JP7029243B2 - motor - Google Patents

Description

The technology disclosed relates to motors.

A rotary electric machine (dual rotor motor) in which two rotors and one stator are configured on the same axis in a three-layer structure, and a common coil that generates different rotating magnetic fields for the two rotors is formed in the stator. Is known (see, for example, Patent Document 1).

In Patent Document 1, each rotor is independently driven by passing a composite current obtained by adding a current corresponding to each rotor to a common coil formed in the stator.

Japanese Patent No. 3480300

However, in the conventional invention, there is a problem that the scale of the inverter for passing the combined current is large, complicated, and expensive. Further, since the torque balance is used so that one of the combined currents does not affect the other torque, there is a problem that the efficiency is low.

Further, when such a dual rotor motor is used for driving operation of a washing machine, it is necessary to switch the rotation direction of each rotor, but there has been a dual rotor motor capable of such switching so far. Not done.

The disclosed technology was made in view of this point, and the purpose is to enable one inverter to independently drive two rotors without supplying a combined current with a simple configuration. It is in.

Further, the purpose is to realize a dual rotor motor capable of switching the rotation direction.

The technique disclosed relates to a motor for drive operation.

The motor includes one stator, an inner rotor and an outer rotor independently rotatably arranged inside and outside the stator, and a control unit that controls rotational drive and magnetization processing of the inner rotor and the outer rotor. , Equipped with. During the drive operation, the control unit switches the magnetic poles of the inner rotor and the magnetization-compatible rotor corresponding to the magnetization of at least one of the outer rotors by magnetization processing, so that the inner rotor and the outer rotor are switched. The rotor can be switched between a synchronous rotation mode in which the rotors rotate in the same direction and a reciprocal rotation mode in which the rotors rotate in opposite directions.

That is, this motor is a so-called dual rotor motor. During the drive operation, the magnetic poles of at least one of the inner rotor and the outer rotor are switched by magnetization processing. By doing so, it is possible to switch between a synchronous rotation mode that rotates in the same direction and a reciprocal rotation mode that rotates in opposite directions.

Therefore, according to this dual rotor motor, the rotation direction can be switched, so that it can be used for the drive operation of the washing machine.

Specifically, the magnetization-compatible rotor has a plurality of switching magnets capable of reversing the magnetic poles by supplying a magnetization current, and the stator supplies the magnetization current to the switching magnet at a predetermined timing. Switching between the synchronous rotation mode and the reciprocal rotation mode is performed, and the switching from the synchronous rotation mode to the reciprocal rotation mode is performed in a state where the magnetization-compatible rotor is rotated and rotated, and the switching magnet is used. The anti-magnetization process for supplying the anti-magnetization current that inverts the magnetic poles may be executed a plurality of times.

Here, the state in which the magnetizing-compatible rotor is rotating around means that the other rotor (non-magnetization-compatible rotor) that does not correspond to magnetization is driven to rotate by supplying a predetermined drive current. A state in which the magnetized rotor is rotating due to the action of an electric current. In the synchronous rotation mode, the magnetized rotor rotates in the same direction in synchronization with the non-magnetized rotor, but as the reversal of the magnetic poles progresses, it gradually tries to rotate in the opposite direction, so that it rotates with it. If the anti-magnetization process is performed in this state, the rotation speed of the magnetizing-compatible rotor decreases and the rotation becomes unstable.

Therefore, it is difficult to switch from the synchronous rotation mode to the reciprocal rotation mode, but by performing the diamagnetic processing in a plurality of steps in stages, the rotating rotation of the magnetizing-compatible rotor can be maintained in a relatively stable state. Therefore, even when switching from the synchronous rotation mode to the reciprocal rotation mode, which is difficult to switch, the rotation direction can be switched with high accuracy in a short time. Since a high induced voltage can be secured after the switching, stable rotation driving with high torque can be performed in the reciprocal rotation mode after the switching.

The stator faces the magnetization-compatible rotor in the radial direction, and has a plurality of magnetization-compatible teeth that supply a driving current and the magnetization current to the switching magnet, and the circumferential length of the switching magnet is the said. It may be larger than the pitch of the magnetization-compatible teeth.

In this case, high torque can be realized at low cost in the reciprocal rotation mode.

The diamagnetic treatment may be performed by repeating the partial diamagnetic treatment for supplying the diamagnetic current to different portions of the switching magnet a plurality of times.

Since each switching magnet is magnetized to a partially and stepwise inverted magnetic pole, diamagnetic processing can be performed on a wide area of the switching magnet without destabilizing the accompanying rotation.

The partial diamagnetic treatment may be performed from one end of the switching magnet in the circumferential direction, or the partial diamagnetic treatment may be performed while accelerating the accompanying rotation of the magnetization-compatible rotor. good.

Partial diamagnetic processing can be performed smoothly without destabilizing the accompanying rotation. Since the accompanying rotation can be maintained for a long time, even a plurality of partial diamagnetic treatments can be stably performed.

The partial demagnetization process includes a long magnetization process in which the anti-magnetization current supply time is long and a short magnetization process in which the anti-magnetization current supply time is short, and the long magnetization process is more than the short magnetization process. , It may be performed on the intermediate portion side in the circumferential direction of the switching magnet.

In this case, the number of partial diamagnetic treatments can be reduced without adversely affecting other parts of the switching magnet.

When the control unit determines that the accompanying rotation of the magnetized rotor is equal to or less than a predetermined rotation speed, it is preferable to perform the long magnetization process and end the diamagnetic process.

By doing so, a relatively high torque can be obtained after the rotating rotation of the magnetization-compatible rotor is stopped, so that it becomes easy to drive the magnetization-compatible rotor in rotation.

The partial demagnetization process includes a strong magnetization process having a large anti-magnetization current and a weak magnetization process having a small anti-magnetization current. It may be done on the end side in the direction.

In this case, the magnetic force of the switching magnet after reversing the magnetization can be strengthened without adversely affecting other parts of the switching magnet.

This motor is suitably used for driving the stirring member of the washing machine and the dehydration tub.

Further, the technique disclosed relates to a motor including an annular stator and a first rotor and a second rotor that can rotate independently of the stator, respectively. At least one of the first rotor and the second rotor has a plurality of switching magnets whose magnetic poles are inverted when a magnetization current is supplied, and by supplying the magnetization current, the rotor having the switching magnet is provided. The first rotor and the second rotor are rotated in a plurality of rotation modes by controlling the magnetization operation of the magnetic pole number switching unit that reverses the magnetic poles and switches the number of magnetic poles and the magnetic pole number switching unit. The control unit is provided with a control unit to be operated, and the control unit is divided into a plurality of times while changing the relative position between the rotor and the number of magnetic poles switching unit when switching the number of magnetic poles of the rotor having the switching magnet. It is characterized by performing a magnetization operation.

In this configuration, while changing the relative position between the rotor having the switching magnet and the number of magnetic poles switching unit, the magnetization operation is performed in a plurality of times. For example, if the magnetization operation is performed only once, the previous pole may remain in a part of the switching magnet, but by performing the magnetization operation in multiple times, the magnetic poles of the entire switching magnet are completely reversed. It is possible to make it. As a result, magnetization switching can be performed stably.

Here, the plurality of rotation modes include a synchronous rotation mode in which the first rotor and the second rotor rotate in the same direction at the same speed, and a reciprocal rotation mode in which the first rotor and the second rotor rotate in different directions. In addition, it also includes a rotation mode in which rotation is performed at an arbitrary rotation ratio or at different torques by rotating in the same direction or in different directions at different speeds.

Further, the independent rotation means that the first rotor and the second rotor are configured so as to be able to realize a plurality of rotation modes without being mechanically fixed.

Further, the first rotor, the second rotor, and the stator may have a radial gap type configuration or an axial gap type configuration.

Further, the annular stator may be substantially annular (for example, C-shaped) having a part thereof magnetically cut out.

The control unit may perform all of the magnetization operations performed in a plurality of times during the rotation of the rotor having the switching magnet.

In this configuration, all the magnetization operations are performed during the rotation of the rotor having the switching magnet. In this way, if all the magnetization steps are performed during rotation while grasping the fluctuation of rotation by rotation control, the moment of inertia effect can also be used, which is the most effective.

The control unit may perform the magnetization operation while the rotation of the rotor having the switching magnet is stopped or during low-speed rotation in which the rotation speed of the rotor is lower than a predetermined rotation speed.

In this configuration, the magnetization operation is performed while the rotor having the switching magnet is stopped rotating or rotating at a low speed. As a result, magnetization switching can be performed stably.

Here, during low-speed rotation, the moment of inertia effect during rotation of the rotor having the switching magnet can be used as compared with the stopped state, and by using the position signal, magnetism becomes the original magnetism. Even in the process before the magnetism occurs, the position of magnetization can be determined more accurately, so that the magnetic poles can be switched accurately and easily.

The control unit performs the magnetization operation at least once while the rotation of the rotor having the switching magnet before starting the magnetization operation is stopped, and then the rotor and the magnetic pole number switching unit are relative to each other. The magnetization operation may be performed for the remaining number of times while changing the position.

In this configuration, magnetization switching can be stably performed by performing the magnetization operation at least once while the rotation of the rotor is stopped before the magnetization operation is started.

The control unit may perform the magnetization operation during the synchronous rotation mode in which the first rotor and the second rotor are rotated in the same direction.

In this configuration, magnetization switching can be performed stably by performing the magnetization operation during the synchronous rotation mode.

The control unit may perform the magnetization operation while switching the energization phase according to the movement of the rotor while the rotor having the switching magnet is rotating.

In this configuration, the switching magnet can be properly switched to the opposite magnetic pole by performing the magnetization operation while switching the energization phase while the rotor having the switching magnet is rotating, and the magnetizing switching can be performed stably. ..

The control unit may perform the magnetization operation while switching the energization phase according to the movement of the rotor by setting the initial phase of the rotor having the switching magnet as the initial value and adding the magnet movement amount. ..

In this configuration, the magnetism switching can be stably performed by adding the magnet movement amount to the initial phase of the rotor having the switching magnet and performing the magnetization operation while switching the energization phase.

The rotor having the switching magnet has a plurality of fixed magnets whose magnetic poles do not reverse when a magnetization current is supplied.
It may be provided with a magnet discriminating unit for discriminating between the switching magnet and the fixed magnet.

In this configuration, since the switching magnet and the fixed magnet can be discriminated by the magnet discriminating unit, the magnetizing switching can be easily performed and the magnetizing switching can be stably performed.

The magnet discrimination unit is composed of a position sensor arranged to face the switching magnet, and the switching magnet has a portion facing the position sensor arranged in a state different from that of the fixed magnet. , May be.

In this configuration, since the switching magnet can be discriminated by the position sensor, the magnetizing switching can be easily performed and the magnetizing switching can be performed stably.

The control unit performs the magnetization operation so as to temporarily demagnetize the switching magnet, and the magnet discrimination unit discriminates between the switching magnet and the fixed magnet by detecting the demagnetized magnet. It may be configured to do so.

In this configuration, since the demagnetized switching magnet can be discriminated by the magnet discriminating unit, the magnetizing switching can be easily performed and the magnetizing switching can be stably performed.

The magnet discrimination unit is composed of a magnetic sensor arranged so as to face the switching magnet, and even if the shape of the portion of the switching magnet facing the magnetic sensor is different from that of the fixed magnet. good.

In this configuration, since the switching magnet can be discriminated by the magnetic sensor, the magnetizing switching can be easily performed and the magnetizing switching can be performed stably.

The magnet discrimination unit is composed of a magnetic sensor arranged so as to face the switching magnet, and the magnetizing state of the portion of the switching magnet facing the magnetic sensor is different from that of the fixed magnet. May be.

In this configuration, since the switching magnet can be discriminated by the magnetic sensor, the magnetizing switching can be easily performed and the magnetizing switching can be performed stably.

At least one of the first rotor and the second rotor has a plurality of fixed magnets whose magnetic poles do not reverse when a magnetization current is supplied, and the control unit is based on the position of the fixed magnets. It may be possible to control the rotational operation of the first rotor and the second rotor.

In this configuration, by controlling the rotational operation of the first rotor and the second rotor based on the position of the fixed magnet, magnetization switching can be easily performed and magnetization switching can be performed stably.

The magnetic pole number switching portion is the teeth of the stator, and the coil wound around the teeth has a larger number of turns on the rotor side having the switching magnet than on the other rotor side. good.

In this configuration, by increasing the number of turns of the teeth coil on the rotor side having the switching magnet, the magnetic flux on the switching magnet side can be concentrated more than on the opposite side, and the magnetic flux density is increased. Magnetization switching can be easily performed, and magnetization switching can be performed stably.

The magnetic pole number switching portion is a tooth of the stator, and the tooth has a width detail so that the width of the tooth on the rotor side having the switching magnet is narrower than the width of the tooth on the other rotor side. May be provided.

In this configuration, the magnetic flux density can be increased by providing width details in the teeth and narrowing the width of the teeth on the rotor side having the switching magnet. That is, the magnetization magnetic flux generated by the current flowing through the coil can be concentrated and flowed toward the switching magnet, and the magnetic pole reversal of the switching magnet can be stably performed with a small current.

Since the width of the teeth on the rotor side having the switching magnet may be narrower than the width of the teeth on the other rotor side, the shape of the width details is not particularly limited. For example, the width of the teeth may be tapered toward the rotor side having the switching magnet, or may be a stepped shape in which the width of the teeth on the rotor side having the switching magnet of the teeth is narrowed.

The magnetic pole number switching portion is the teeth of the stator, and the angular width or cross-sectional area of the tip portion of the teeth is smaller on the rotor side having the switching magnet than on the other rotor side. May be.

In this configuration, the angular width or cross-sectional area of the tip of the tooth is made smaller on the rotor side having the switching magnet, so that the magnetic flux density is increased to facilitate magnetizing switching and magnetization. Switching can be performed stably.

According to the disclosed technique, the first rotor and the second rotor can be rotated in a plurality of rotation modes with a simple configuration. It is possible to realize a dual motor that can switch the direction of rotation.

It is a schematic perspective view of the washing machine disclosed in this embodiment. It is a schematic cross-sectional view in XX line of FIG. It is a schematic vertical sectional view which shows the assembly structure of a motor. It is a circuit diagram which shows the structure of an inverter. It is a top view which shows the structure of a motor, and shows the state which the number of magnetic poles of an outer rotor is 32 poles. It is a figure explaining the drive operation of a motor in the synchronous rotation mode (the number of magnetic poles of an outer rotor is 32 poles). It is a figure explaining the drive operation of a motor in the reciprocal rotation mode (the number of magnetic poles of an outer rotor is 16 poles). It is a figure which shows the rotation direction of a pulsator and a dehydration tank in a reciprocal rotation mode (a) and a synchronous rotation mode (b). It is a figure for demonstrating the magnetization process from a synchronous rotation mode to a reciprocal rotation mode. It is a plane sectional view which shows the movement path of the magnetic flux in the synchronous rotation mode. It is a figure for demonstrating the magnetization process from the reciprocal rotation mode to the synchronous rotation mode. It is a plane sectional view which shows the movement path of the magnetic flux in the reciprocal rotation mode. It is a figure which shows the BH curve when the magnets having different coercive force are used for the fixed magnet and the switching magnet. It is a plan sectional view which shows the structure of the motor of the modification 1, and shows the state which the number of magnetic poles of an outer rotor is 32 poles. It is a plan sectional view which shows the structure of the motor of the modification 1, and shows the state which the number of magnetic poles of an outer rotor is 16 poles. It is a figure for demonstrating the procedure of the magnetization processing with the motor of the modification 1. FIG. It is a figure for demonstrating the procedure of the magnetization processing with the motor of the modification 1. FIG. It is a figure for demonstrating the procedure of the magnetization processing with the motor of the modification 1. FIG. It is a figure for demonstrating the procedure of the magnetization processing with the motor of the modification 1. FIG. It is a figure for demonstrating the procedure of the magnetization processing with the motor of the modification 1. FIG. It is a figure for demonstrating the procedure of the magnetization processing with the motor of the modification 1. FIG. It is a figure explaining the positional relationship between a switching magnet and a tooth when the energization phase is not switched. It is a figure explaining the positional relationship between a switching magnet and a tooth when switching the energization phase. It is a figure explaining the arrangement of the magnetic sensor with respect to a switching magnet and a fixed magnet. It is a figure when the switching magnet is detected by the magnetic sensor. It is a figure explaining the arrangement of the magnetic sensor with respect to a switching magnet and a fixed magnet. It is a figure when the different pole part of a fixed magnet is detected by a magnetic sensor. It is a partially enlarged view of the main part which shows the modification 2 of a motor. It is a flow chart which shows the basic operation example of the washing machine which used the motor of the modification 2. It is a figure for demonstrating the 1st magnetization process. (A) to (D) show a series of flow of the first magnetization process. It is a flow chart of the 1st magnetization process. It is a flow chart of the 2nd magnetization process. It is a figure for demonstrating application example 1 of partial diamagnetism processing. (A) and (B) show the series of flows. It is a figure for demonstrating application example 2 of partial diamagnetism processing. (A) and (B) show the series of flows. It is a figure for demonstrating application example 2 of partial diamagnetism processing. It is a figure for demonstrating the application example of the diamagnetism processing. (A) to (C) show the series of flows. It is a top view which shows the structure of the motor of the modification 3. FIG. It is a top view which shows the structure of the motor of the modification 4. FIG. It is a plan sectional view which shows the structure of the motor of the modification 5. It is a plan sectional view of the state where the groove part is formed in the tip part of a tooth.

Hereinafter, embodiments of the disclosed technology will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its application or its use.

<Washing machine configuration>
FIG. 1 shows a washing machine 1 to which the motor of the present embodiment is applied. The washing machine 1 is a fully automatic washing machine in which each process of washing, rinsing, and dehydration can be performed by automatic control. The washing machine 1 has a vertically long rectangular box-shaped housing 2, and an input port 4 that opens and closes with a lid 3 is formed on the upper portion thereof. Laundry is taken in and out through the loading port 4 (so-called vertical washing machine). Various switches and display units operated by the user are provided behind the slot 4.

As shown in FIG. 2, a washing tub 10, a dehydration tub 11, a motor 12, a pulsator 13 (an example of a stirring member), a balancer 14, a control device 15, and the like are installed inside the housing 2. In particular, in this washing machine 1, the disclosed technology is applied to the motor 12 for drive operation, so that the washing machine 1 can exhibit appropriate performance according to each process in the washing machine 1 in a compact size.

The washing tub 10 is a bottomed cylindrical container capable of storing water, and is suspended inside the housing 2 by a plurality of hanging members 16 with the opening facing the upper inlet 4. Water can be injected into the washing tub 10 through a water injection mechanism (not shown). A drainage pipe 17 whose opening and closing is controlled by a valve is connected to the lower part of the washing tub 10, and unnecessary water is drained to the outside of the washing machine 1 through the drainage pipe 17.

The dehydration tub 11 is a bottomed cylindrical container that receives laundry, which is one size smaller than the washing tub 10. The dehydration tub 11 is housed in the washing tub 10 in a state in which the opening thereof can be rotated around the vertical axis J extending in the vertical direction toward the charging port 4. All the laundry processing is performed inside the dehydration tub 11. A large number of drain holes 11a are formed over the entire surface of the cylindrical peripheral wall of the dehydration tank 11 (only a part thereof is shown in the figure).

A balancer 14 is installed at the opening of the dehydration tank 11. The balancer 14 is an annular member containing a plurality of balls and viscous fluids therein, and adjusts the imbalance of weight balance caused by the bias of the laundry when the dehydration tub 11 is rotated. At the bottom of the dehydration tank 11, a disk-shaped pulsator 13 having a stirring blade on the upper surface is rotatably installed.

The control device 15 (which constitutes a control unit) is composed of hardware such as a CPU and ROM and software such as a control program, and comprehensively controls each process performed by the washing machine 1. The control device 15 is electrically connected to various switches, motors 12, and the like, and a control program executes each process of washing, rinsing, and dehydration according to a user's instruction.

The control device 15 controls the drive operation of the motor 12. For example, in the washing process, the motor 12 rotates and drives the pulsator 13 and the dehydration tank 11 while reversing them at regular intervals to stir the laundry together with water and detergent. In the dehydration process, the motor 12 rotates and drives the pulsator 13 and the dehydration tank 11 in a fixed direction at high speed in synchronization with each other, and the laundry is pressed against the peripheral wall by the action of centrifugal force to dehydrate the laundry.

Further, the control device 15 also controls the magnetization process of the motor 12. That is, the control device 15 controls a process of switching the magnetic poles (S pole, N pole) of the magnet provided in the motor 12 and energizing and demagnetizing the magnetic force (details will be described later).

(motor)
The motor 12 has a flat columnar appearance having a diameter smaller than that of the washing tub 10, and is assembled to the lower side of the washing tub 10 so that the vertical axis J passes through the center thereof.

As shown in FIG. 3, the motor 12 includes an outer rotor 20 (second rotor), an inner rotor 30 (first rotor), an inner shaft 40, an outer shaft 50, a stator 60, and the like. That is, the motor 12 is a so-called dual rotor motor in which the outer rotor 20 and the inner rotor 30 are provided on the outer and inner sides of one stator 60 in the radial direction.

The outer rotor 20 and the inner rotor 30 are connected to the pulsator 13 and the dehydration tank 11 without interposing a clutch, an accelerator or a speed reducer, and are configured to directly drive them.

The outer rotor 20 and the inner rotor 30 share the coil 63 of the stator 60, and by supplying a drive current to the coil 63, the motor 12 rotates each of the outer rotor 20 and the inner rotor 30 independently. It can be driven. The stator 60 is attached to a bearing bracket 70 provided on the bottom surface of the washing tub 10.

The outer rotor 20 is a flat bottomed cylindrical member, and is composed of a bottom wall portion 21 having an open central portion, a rotor yoke 22 erected on the peripheral edge of the bottom wall portion 21, and a plurality of arc-shaped permanent magnets. It has an outer magnet 24 of the above. The bottom wall portion 21 and the rotor yoke 22 are formed by pressing an iron plate so as to function as a back yoke.

In the present embodiment, the outer rotor 20 is a concave rotor. 16 outer magnets 24 are arranged on the outer rotor 20 so as to be arranged at regular intervals in the circumferential direction, and are fixed to the inner surface of the rotor yoke 22.

The outer magnet 24 can invert the magnetic poles (invert from S pole to N pole or from N pole to S pole) by magnetization processing (switching magnet described later). Further, the outer magnet 24 can strengthen or weaken the magnetic force (enhancement or demagnetization). That is, in the present embodiment, the outer rotor 20 is a rotor corresponding to the magnetization processing thereof, and the number of magnetic poles can be switched between 16 poles and 32 poles (magnetization compatible rotor, details are described). Later).

The inner rotor 30 is a flat bottomed cylindrical member having a smaller outer diameter than the outer rotor 20, and has an inner bottom wall portion 31 having an open central portion and an inner side erected around the inner bottom wall portion 31. It has a peripheral wall portion 32 and a plurality of inner magnets 34 composed of rectangular plate-shaped permanent magnets (fixed magnets described later).

In the present embodiment, the inner rotor 30 is a spoke type rotor. In the inner rotor 30, 32 inner magnets 34 are arranged so as to be arranged radially at regular intervals in the circumferential direction, and are fixed to the inner peripheral wall portion 32. Rotor cores 33 are arranged in the circumferential direction between the inner magnets 34.

The inner shaft 40 is a columnar shaft member, and is rotatably supported by a bearing bracket 70 via an inner bearing 73, an outer shaft 50, and ball bearings 71 and 72. The lower end of the inner shaft 40 is connected to the outer rotor 20. The upper end of the inner shaft 40 is connected to the pulsator 13.

The outer shaft 50 is a cylindrical shaft member that is shorter than the inner shaft 40 and has an inner diameter larger than the outer diameter of the inner shaft 40. The upper and lower inner bearings 73, 73, the inner shaft 40, and the ball bearings 71, 72. It is rotatably supported by the bearing bracket 70 via the bearing bracket 70. The lower end of the outer shaft 50 is connected to the inner rotor 30. The upper end of the outer shaft 50 is connected to the dehydration tank 11.

The stator 60 is formed of an annular member having an outer diameter smaller than the inner diameter of the outer rotor 20 and an inner diameter larger than the outer diameter of the inner rotor 30. As shown in FIG. 5, the stator 60 is provided with a plurality of teeth 61, coils 63, and the like embedded in the resin. The stator 60 of the present embodiment is provided with 24 I-shaped teeth 61 and a coil 63.

The steel 61 is an iron member having an I-shaped cross section in the direction in which the vertical axis J extends. The teeth 61 are arranged on the entire circumference of the stator 60 so as to be arranged radially at equal intervals via the slots. The inner and outer side ends of the teeth 61 in the radial direction project from both corners in a flange shape in the circumferential direction.

The teeth 61 has an inner flange portion 61a at its inner side end and an outer flange 61b at its outer side end. In the present embodiment, the outer portion of these teeth 61 where the outer rotor 20 is located, including the outer flange portion 61b, constitutes a magnetization-corresponding tooth.

The gap between the outer flanges 61b, 61b of the two adjacent teeth 61 (outer opening of the slot) is larger than the gap between the inner flanges 61a, 61a of the two adjacent teeth 61 (inner opening of the slot). It's getting bigger. By increasing the outer opening of the slot in this way, it becomes easier to perform the magnetization processing of the outer rotor 20.

A coil 63 is formed in each tooth 61 by continuously winding three wires coated with an insulating material through a slot in a predetermined order and configuration (so-called concentration). roll). Each tooth 61 on which the coil 63 is formed is embedded in a thermosetting resin by molding in an insulated state with only the end faces of the inner flange portion 61a and the outer flange portion 61b exposed.

The stator 60, the inner rotor 30, and the outer rotor 20 face the inner flange portion 61a with a slight gap between the rotor core 33 and the outer flange portion 61b with a slight gap between the outer flange portion 61b. It is assembled.

A position sensor 64 is arranged between the adjacent teeth 61. The position sensor 64 is arranged on the side of the inner rotor 30 and is for grasping the position of the inner rotor 30.

As shown in FIG. 4, a three-phase inverter 18 is connected to the motor 12. By controlling the inverter 18 by the control device 15, in the motor 12, the driving currents of three phases (U phase, V phase, W phase) are energized to each coil 63 of the stator 60 at a predetermined timing. By doing so, different magnetic poles are simultaneously generated on the outer side and the inner side of the teeth 61, and the outer rotor 20 and the inner rotor 30 rotate independently with the rotating magnetic field.

In the motor 12, one rotor of the outer rotor 20 and the inner rotor 30 is used as a main rotor, and the other rotor is used as a sub rotor in order to set a drive control reference. The drive current is controlled with reference to the main rotor, and in this motor 12, the inner rotor 30 is the main rotor.

Further, in the motor 12, the control device 15 controls the inverter 18, so that the predetermined coil 63 of the stator 60 is energized with a magnetization current sufficiently larger than the drive current at a predetermined timing. By doing so, the predetermined outer magnet 24 of the outer rotor 20 is magnetized.

<Rotation mode>
The motor 12 can be driven and operated in a plurality of rotation modes by switching the number of magnetic poles of the outer rotor 20 by magnetization processing. Since the motor 12 is the motor of the washing machine 1, the main rotation modes are a mode in which the outer rotor 20 and the inner rotor 30 are synchronously rotated in the same direction (synchronous rotation mode), and the outer rotor 20 and the inner rotor 20. This is a mode in which the rotors 30 are rotated in opposite directions (reciprocal rotation mode).

6 and 7 show the positions of the stator 60, the outer rotor 20, and the inner rotor 30 during the rotation of the motor 12 with an electric angle of 360 °, divided into six steps. The principle that the outer rotor 20 and the inner rotor 30 rotate in the synchronous rotation mode and the reciprocal rotation mode is schematically shown. The drive current is controlled by detecting the position of the inner rotor 30 with the position sensor 64 and specifying the positions of the outer rotor 20 and the inner rotor 30 based on the position.

(Synchronous rotation mode)
In the synchronous rotation mode, the number of magnetic poles of the outer rotor 20 is 32, which is the same as that of the inner rotor 30. FIG. 6 shows the machine angle of 45 °. When a drive current is passed through the three-phase coils 63 of the U phase, the V phase, and the W phase, magnetic poles are generated in the teeth 61. The magnetic poles are opposite poles on the inner rotor 30 side and the outer rotor 20 side of the teeth 61. In the following description, only the pole on the inner rotor 30 side of the teeth 61 will be described.

The first step (1) represents a state in which the inner rotor 30 side of the U-phase and V-phase teeth 61 is the N pole, and the inner rotor 30 side of the W-phase teeth 61 is the S pole. Therefore, the outer rotor 20 side of the U-phase and V-phase teeth 61 has an S pole, and the outer rotor 20 side of the W-phase teeth 61 has an N pole.

In the state of the first step (1), the outer rotor 20 and the inner rotor 30 receive a force rotating to the right in FIG. 6 as torque in a state where the electric angle is deviated by 180 °.

In the state of the second step (2), the magnetic poles of the V-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the N pole, the V-phase teeth 61 becomes the S pole, the W-phase teeth 61 remains the S pole, and the outer rotor 20 and the inner rotor 30 remain. Move to the right.

In the state of the third step (3), the magnetic poles of the W-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the N pole, the V-phase teeth 61 remains the S pole, the W-phase teeth 61 becomes the N pole, and the outer rotor 20 and the inner rotor 30 move to the right. Moving.

In the state of the fourth step (4), the magnetic poles of the U-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side becomes the S pole, the V-phase teeth 61 remains the S pole, the W-phase teeth 61 remains the N pole, and the outer rotor 20 and the inner rotor 30 move to the right. Moving.

In the state of the fifth step (5), the magnetic poles of the V-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the S pole, the V-phase teeth 61 becomes the N pole, the W-phase teeth 61 remains the N pole, and the outer rotor 20 and the inner rotor 30 remain. Move to the right.

In the state of the sixth step (6), the magnetic poles of the W-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the S pole, the V-phase teeth 61 remains the N pole, the W-phase teeth 61 becomes the S pole, and the outer rotor 20 and the inner rotor 30 move to the right. Moving.

In this way, the outer rotor 20 and the inner rotor 30 rotate in the same direction at the same speed (synchronous rotation mode). The phases of the outer rotor 20 and the inner rotor 30 may be slightly out of phase due to a load or load fluctuation, but in this example, it is described as assuming that there is no phase shift.

Further, in this example, the drive current is controlled by using the position sensor 64, but the present invention is not limited to this. For example, instead of the position sensor 64, a magnetic sensor that detects a magnet on the inner rotor 30 side or the outer rotor 20 side may be used. Further, a so-called sensorless method may be adopted, such as using an induced voltage or using a detected current. Further, the drive current may be controlled by using another method such as an encoder.

(Reciprocal rotation mode)
As shown in FIG. 7, in the reciprocal rotation mode, the number of magnetic poles of the outer rotor 20 is 16 poles.

The first step (1) represents a state in which the inner rotor 30 side of the U-phase and V-phase teeth 61 is the N pole, and the inner rotor 30 side of the W-phase teeth 61 is the S pole. Therefore, the outer rotor 20 side of the U-phase and V-phase teeth 61 has an S pole, and the outer rotor 20 side of the W-phase teeth 61 has an N pole.

In the state of the first step (1), the inner rotor 30 receives a force rotating to the right in FIG. 7 as a torque. On the other hand, the outer rotor 20 receives a force that rotates to the left in FIG. 7 as torque.

In the state of the second step (2), the magnetic poles of the V-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the N pole, the V-phase teeth 61 becomes the S pole, the W-phase teeth 61 remains the S pole, and the inner rotor 30 moves to the right. Then, the outer rotor 20 moves to the left.

In the state of the third step (3), the magnetic poles of the W-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the N pole, the V-phase teeth 61 remains the S pole, the W-phase teeth 61 becomes the N pole, the inner rotor 30 moves to the right, and the outer rotor 30 moves to the right. The rotor 20 moves to the left.

In the state of the fourth step (4), the magnetic poles of the U-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side becomes the S pole, the V-phase teeth 61 remains the S pole, and the W-phase teeth 61 remains the N pole, the inner rotor 30 moves to the right, and the outer rotor 30 moves to the right. The rotor 20 moves to the left.

In the state of the fifth step (5), the magnetic poles of the V-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the S pole, the V-phase teeth 61 becomes the N pole, the W-phase teeth 61 remains the N pole, and the inner rotor 30 moves to the right. Then, the outer rotor 20 moves to the left.

In the state of the sixth step (6), the magnetic poles of the W-phase teeth 61 are inverted. As a result, the U-phase teeth 61 on the inner rotor 30 side remains the S pole and the V-phase teeth 61 remains the N pole, the W-phase teeth 61 becomes the S pole, the inner rotor 30 moves to the right, and the outer rotor 30 moves to the right. The rotor 20 moves to the left. At this time, the amount of movement of the outer rotor 20 is twice that of the inner rotor 30.

In this way, the outer rotor 20 and the inner rotor 30 rotate in different directions at different speeds (reciprocal rotation mode).

The synchronous rotation mode and the reciprocal rotation mode can be configured by combining the number of magnetic poles other than these or by different rotation ratios. That is, the synchronous rotation mode and the reciprocal rotation mode include the case of rotating at an arbitrary rotation ratio or rotating with different torques.

In this way, one inverter 18 can independently rotate and drive the outer rotor 20 and the inner rotor 30 that share one stator 60. As a result, the control device 15 switches the drive operation of the motor 12 between the synchronous rotation mode and the reciprocal rotation mode, so that the pulsator 13 and the dehydration tank 11 are rotated in the same direction and the reciprocal direction in the washing machine 1. You can do it.

That is, as shown in FIG. 8A, by switching to the reciprocal rotation mode, the pulsator 13 and the dehydration tank 11 rotate in opposite directions. As shown in FIG. 8B, by switching to the synchronous rotation mode, the pulsator 13 and the dehydration tank 11 rotate in the same direction with each other.

(Motor magnetization treatment)
In the washing machine 1, in order to switch the operation mode between the synchronous rotation mode and the reciprocal rotation mode, the control device 15 refers to the outer rotor 20 during the driving operation, in other words, during the washing process. The number of magnetic poles is switched by performing the magnetization process.

FIG. 9 is a plan sectional view showing a main part of the motor, and shows a state of a machine angle of 45 °. As described above, the outer magnet 24 is all composed of the switching magnet 25. The inner magnets 34 are all composed of fixed magnets 35.

The switching magnet 25 is a magnet whose polarity is reversed when a magnetization current is supplied to the coil 63 as a magnetic pole number switching unit. The fixed magnet 35 is a magnet in which the polarity of the magnet is not reversed even if a magnetization current is supplied to the coil 63. It is not necessary to depend on the magnitude of coercive force and the type of magnet, which will be described later. Reversing or not reversing indicates the polarity of the entire magnet, and even if there is a reverse pole in a part, it may be determined by the total magnetic flux.

The number of poles St of the stator 60 is 24 poles, the number of poles Mi of the inner rotor 30 is 32 poles, and the number of poles Mo of the outer rotor 20 is 32 poles or 16 poles. The ratio of magnetic poles is St: Mi: Mo = 3: 4: 4 or 2.

FIG. 9 shows the state of the synchronous rotation mode. The switching magnets 25 are all S poles. By doing so, as shown in FIG. 10, the rotor yoke 22 of the outer rotor 20 between the adjacent switching magnets 25 becomes the north pole. Therefore, the number of magnetic poles of the outer rotor 20 is 32 poles.

Since the north pole portion of the rotor yoke 22 does not have a salient pole structure, the magnetic resistance between the rotor yoke 22 and the teeth 61 is substantially the same. By using a concave rotor without such a salient pole structure, it is possible to obtain a configuration in which vibration and noise are suppressed.

As shown by the alternate long and short dash line in FIG. 10, the magnetic flux emitted from the N pole portion of the rotor yoke 22 enters the teeth 61, and enters the switching magnet 25 (S pole) from different teeth 61.

In this case, since the gap (air gap) between the rotor yoke 22 (N pole) and the teeth 61 is large, the induced voltage becomes small. This is advantageous for dehydration processing, which requires high speed and low torque.

On the other hand, FIG. 11 shows the state of the reciprocal rotation mode. The switching magnet 25 is configured such that the north pole and the south pole are arranged alternately. By having such a configuration of the switching magnet 25, as shown in FIG. 12, the rotor yoke 22 of the outer rotor 20 between the switching magnets 25 does not form a magnetic pole. Therefore, the number of magnetic poles of the outer rotor 20 is 16 poles.

As shown by the alternate long and short dash line in FIG. 12, the magnetic flux emitted from the switching magnet 25 (N pole) enters the teeth 61, and enters the switching magnet 25 (S pole) from different teeth 61.

In this case, since the gap (air gap) between the switching magnet 25 (N pole) and the teeth 61 is smaller than that in the case of 32 poles, the induced voltage becomes large. This is advantageous for washing processes that require low speed and high torque.

(Switching the number of magnetic poles)
FIG. 9 shows a case where the number of magnetic poles of the outer rotor 20 is switched from 32 poles to 16 poles (switching from the synchronous rotation mode to the reciprocal rotation mode). A magnetizing current is passed through the coil 63 to generate a magnetic field so that the magnetic field lines shown by the arrows in FIG. 9 are formed on the first tooth 61 from the bottom and the second tooth 61 from the bottom. Thereby, the magnetic pole of the first switching magnet 25 from the bottom can be inverted from the S pole to the N pole.

FIG. 11 shows a case where the number of magnetic poles of the outer rotor 20 is switched from 16 poles to 32 poles (switching from the reciprocal rotation mode to the synchronous rotation mode). A magnetizing current is passed through the coil 63 to generate a magnetic field so that the magnetic field lines shown by the arrows in FIG. 11 are formed on the first tooth 61 from the bottom and the second tooth 61 from the bottom. Thereby, the magnetic pole of the first switching magnet 25 from the bottom can be inverted from the N pole to the S pole.

When switching the magnetic poles, the previous pole may remain in a part of the switching magnet 25 in which the magnetic poles are inverted, and the switching of the magnetic poles may not be completed. In that case, it is possible to complete the magnetization switching by appropriately matching the angle of the outer rotor 20 and the phase of the magnetization current flowing through the coil 63 and performing the magnetization treatment a plurality of times. The procedure for performing such a plurality of magnetization treatments will be described later separately.

Here, the magnetic reluctance of the magnetic flux path passing through the switching magnet 25 between the magnetized teeth 61 is larger than the magnetic resistance of the magnetic flux path passing near the air gap of the inner rotor 30. That is, in the inner rotor 30, a part of the magnetic flux passing through the fixed magnet 35 is branched so as to pass in the vicinity of the air gap.

As a result, when a magnetization current is supplied, a larger amount of magnetic flux flows in the switching magnet 25 than in the fixed magnet 35, and the magnetization force of the switching magnet 25 part becomes larger than the magnetization force of the fixed magnet 35 part. ..

By appropriately setting the magnetic path of the magnetic flux for magnetism in this way, for example, even when the switching magnet 25 and the fixed magnet 35 are composed of ferrite magnets having the same coercive force, only the switching magnet 25 can be used. Magnetic flux switching can be performed stably.

The switching magnet 25 and the fixed magnet 35 may be composed of two or more types of magnets having different coercive forces. For example, by making the coercive force of the fixed magnet 35 larger than the coercive force of the switching magnet 25, more stable magnetization can be obtained. Further, by using a rare earth magnet for the fixed magnet 35 of the inner rotor 30, the torque balance between the inner rotor 30 and the outer rotor 20 can be more easily obtained.

FIG. 13 is a diagram showing a BH curve (magnetic hysteresis curve) when magnets having different coercive forces are used for the fixed magnet 35 and the switching magnet 25. Here, when a magnetic field that does not exceed + A or more, −A or less, and the coercive force of the fixed magnet 35 is generated by passing a magnetization current through the coil 63, as can be seen from the figure, the magnetic poles of the switching magnet 25 are inverted. It is possible. The magnetizing current may be a pulse current, and magnetization is possible in a time of about several tens of msec.

By the way, in magnetizing the switching magnet 25, it is advantageous that the voltage applied to the coil 63 is as high as possible in order to increase the magnetization current. Also, when high-speed rotation is performed with low torque such as in the dehydration stroke, it is easier to do it when the voltage is high. However, in the case of low-speed rotation with high torque such as a washing stroke or a rinsing stroke, the efficiency of the inverter 18 is generally better if it is not too high.

Therefore, in this motor 12, when high-speed rotation is performed with low torque, the same voltage as the magnetization processing is supplied to the inverter 18, while when low-speed rotation is performed with high torque, a voltage lower than the magnetization voltage is supplied to the inverter. I am trying to supply to 18. As a result, power consumption can be reduced.

According to this motor 12, the outer rotor 20 and the inner rotor 30 can be rotated in a plurality of rotation modes without supplying a combined current. Therefore, unlike the conventional case, a plurality of inverters 18 for supplying a combined current are not required, and the scale of the inverter 18 can be reduced to make the product more compact and reduce the cost.

Further, since the motor 12 does not require the separation current processing of the combined current, it is not easily affected by the harmonic current, and vibration and sound due to the harmonic distortion are not generated.

Further, since the magnetizing current is supplied to the coil 63 to switch the magnetic poles of the switching magnet 25 using the saturated magnetizing region, the magnetic flux amount is stable, and the sound and vibration caused by the variation in the magnetic flux amount. Is less likely to occur.

<Motor deformation example 1>
FIG. 14 shows a modification 1 (motor 12A) of the motor 12. Hereinafter, the same parts as those in the above-described embodiment are designated by the same reference numerals, the description thereof will be omitted, and only the differences will be described (the same applies to the following modified examples).

The outer rotor 20 is an SPM type rotor, and 32 outer magnets 24 are arranged so that S poles and N poles are alternately arranged in the circumferential direction, and are fixed to the inner surface of the rotor yoke 22.

The outer magnet 24 is composed of a switching magnet 25 and a fixed magnet 35. Specifically, among the five outer magnets 24 shown in FIG. 14, the first, second, and fifth magnets from the bottom are composed of the switching magnet 25. The third and fourth magnets from the bottom are composed of fixed magnets 35. That is, two adjacent magnets are composed of magnets having the same function.

Then, when a magnetization current is supplied to the coil 63 to invert the magnetic poles of all the switching magnets 25, as shown in FIG. 15, the first and fifth switching magnets 25 from the bottom are inverted from the S pole to the N pole. Then, the second switching magnet 25 from the bottom is inverted from the N pole to the S pole. In this way, the set of two adjacent S-pole magnets and the set of two adjacent N-poles are switched so as to be arranged alternately in the circumferential direction, so that the number of magnetic poles of the outer rotor 20 becomes 16 poles. Become.

Here, when the drive current is supplied to the coil 63 when the number of magnetic poles of the outer rotor 20 is 32, both the outer rotor 20 and the inner rotor 30 are clockwise as shown by an arrow in FIG. Rotate. That is, it can be rotationally driven in the synchronous rotation mode.

On the other hand, when the outer rotor 20 has 16 poles and a drive current is supplied to the coil 63, the outer rotor 20 rotates counterclockwise and the inner rotor 30 rotates clockwise as shown by an arrow in FIG. Rotate. That is, it can be rotationally driven in the reciprocal rotation mode.

(Switching the number of magnetic poles)
In the motor 12A of the first modification, the number of magnetic poles is switched by magnetizing the switching magnet 25 in a plurality of times. Here, a case where the number of magnetic poles of the outer rotor 20 is switched from 32 poles to 16 poles (switching from the synchronous rotation mode to the reciprocal rotation mode) will be described with reference to FIGS. 16 to 21. When switching the magnetic poles of the outer rotor 20 from 16 poles to 32 poles (switching from the reciprocal rotation mode to the synchronous rotation mode), the following procedure may be performed in reverse in the same way, and the description thereof will be omitted.

As shown in FIG. 16, the outer rotor 20 is positioned. Specifically, a current is passed through the coil 63 so that the magnetic field lines shown by the arrows in FIG. 16 are formed in the first tooth 61 (U phase) from the bottom and the second tooth 61 (W phase) from the bottom. To generate a magnetic field.

Here, a current (positioning current) of about 5 A is passed so that a magnetic field sufficient to fix the outer rotor 20 at the position shown in FIG. 16 is generated. As a result, the magnetic poles of the outer rotor 20 and the inner rotor 30 facing the teeth 61 are balanced and stopped at the position shown in FIG.

Next, as shown in FIG. 17, at the position where the outer rotor 20 is stopped, the coil is formed so that the magnetic field lines shown by the arrows in FIG. 17 are formed on the first tooth 61 from the bottom and the second tooth 61 from the bottom. A current is passed through 63 to generate a magnetic field. Here, a magnetizing current (magnetization current) of, for example, about 30 A, which is larger than that when the outer rotor 20 is positioned, is made to flow. As a result, in the first and second switching magnets 25 from the bottom, the magnetic poles are partially inverted as shown in FIG.

Next, as shown in FIG. 18, the magnetic field lines indicated by the arrows in FIG. 18 are formed on the first (U phase), second (W phase), and third (V phase) teeth 61 from the bottom. , A positioning current is passed through the coil 63 to generate a magnetic field. As a result, the magnetic poles of the outer rotor 20 and the inner rotor 30 are balanced and stopped at the position shown in FIG.

Next, as shown in FIG. 19, at the position where the outer rotor 20 is stopped, the magnetic field lines shown by the arrows in FIG. 19 are formed on the first tooth 61 from the bottom and the second tooth 61 from the bottom. A magnetizing current is passed through the coil 63 to generate a magnetic field. At this time, since the region of the switching magnet 25 second from the bottom facing the teeth 61 is widened, the reversal of the magnetic poles from the N pole to the S pole is completed.

Next, as shown in FIG. 20, a positioning current is passed through the coil 63 to generate a magnetic field so that the magnetic field lines indicated by the arrows in FIG. 20 are formed on the first, second, and third teeth 61 from the bottom. Let me. As a result, the magnetic poles of the outer rotor 20 and the inner rotor 30 facing the teeth 61 are balanced and stopped at the position shown in FIG.

Next, as shown in FIG. 21, at the position where the outer rotor 20 is stopped, the magnetic field lines shown by the arrows in FIG. 21 are formed on the first tooth 61 from the bottom and the second tooth 61 from the bottom. A magnetizing current is passed through the coil 63 to generate a magnetic field. At this time, since the region of the switching magnet 25, which is the first from the bottom, faces the teeth 61 is widened, the reversal of the magnetic poles from the S pole to the N pole is completed.

(Possibilities of application)
In the motor 12A of the first modification, the magnetization treatment is performed while the rotation of the outer rotor 20 is stopped, but the magnetization treatment may be performed while the outer rotor 20 is rotating at a low speed. In that case, before the start of the magnetization treatment (during the rotation stop), the magnetization treatment is performed at least once, and then the outer rotor 20 is rotated at a low speed to change the relative position with the teeth 61, and the remaining number of times. , Magnetization processing may be performed. That is, the magnetization current may be applied at the timing when the outer rotor 20 during low-speed rotation reaches the position where it should be magnetized. In this case, it is preferable to perform the magnetization treatment during the synchronous rotation mode.

For the positioning of the outer rotor 20, a sensorless position signal may be used, or the position signal of the inner magnet 34 on the inner rotor 30 side by the position sensor 64 may be used. Further, a position signal processed by a position signal such as averaging between the inner rotor 30 side and the outer rotor 20 side may be used.

Further, since the moment of inertia of the outer rotor 20 can be used while the outer rotor 20 is rotating at a low speed, the position of the switching magnet 25 can be accurately determined by using the position signal even when the magnetization processing is not completed. .. Further, if all the magnetization processing is performed during the rotation of the outer rotor 20 while grasping the fluctuation of the rotation of the outer rotor 20 by the rotation control by the control device 15, the moment of inertia can be used, which is effective.

By the way, when the magnetization process is performed during the rotation of the outer rotor 20, it is preferable to switch the energization phase according to the movement of the outer rotor 20.

That is, when magnetizing only with the U-phase teeth 61, if the outer rotor 20 rotates faster than the energization time of the magnetizing current, the position of the teeth 61 with respect to the switching magnet 25 shifts as shown in FIG. Therefore, proper magnetization processing may not be possible. It is conceivable to slow down the rotation speed of the outer rotor 20, but this is not preferable because the effect of the moment of inertia of the outer rotor 20 is reduced and the position accuracy and the magnetizing fluctuation are increased.

Therefore, in such a case, as shown in FIG. 23, it is advisable to switch the teeth 61 to be magnetized from the U phase to the V phase according to the amount of rotation of the outer rotor 20. Then, the target switching magnet 25 can be appropriately magnetized.

At this time, the energization phase during magnetism is performed by setting the initial phase of the outer rotor 20 as the initial value and adding the movement amount of the switching magnet 25.

The initial value of the initial phase means the current phase when the magnetization current is applied. For example, the initial value when magnetizing in the U phase is 0 ° + offset amount, the initial value when magnetizing in the W phase is -120 ° + offset amount, and the initial value when magnetizing in the V phase is 120 °. + Offset amount. The offset amount is a parameter adjusted so that the magnetization current peaks when the switching magnet 25 reaches the target position.

By the way, in order to invert the magnetic poles of the switching magnet 25 and switch the number of magnetic poles, it is necessary to determine the positions of the switching magnet 25 and the fixed magnet 35. Therefore, in the motor 12A of the first modification, a position sensor or a magnetic sensor 65 is used as the magnet discrimination unit.

As shown in FIG. 24, in the outer rotor 20, a set of two adjacent switching magnets 25 and a set of two adjacent fixed magnets 35 are arranged so as to be arranged alternately in the circumferential direction. The lower end of the switching magnet 25 projects downward from the lower end of the fixed magnet 35 and extends. That is, the switching magnet 25 is longer than the fixed magnet 35.

Then, the magnetic sensor 65 is arranged so as to face the portion of the switching magnet 25 that is longer than the fixed magnet 35. The magnetic sensor 65 is fixed to, for example, a stator 60 or another structure.

At the position of the outer rotor 20 shown in FIG. 24, the magnetic sensor 65 is located below the fixed magnet 35. Here, when the outer rotor 20 rotates, as shown in FIG. 25, the magnetic sensor 65 faces the switching magnet 25 and receives a signal different from the state shown in FIG. 24. Based on this different signal, the switching magnet 25 and the fixed magnet 35 can be discriminated by the magnetic sensor 65. Then, the control device 15 controls the rotational operation of the outer rotor 20 and the inner rotor 30 based on the position of the fixed magnet 35.

The magnetic sensor 65 may be arranged on either the outside or the inside of the outer rotor 20, and the same function can be obtained even if the magnetic sensor 65 is arranged on the end face portion. Further, even if the configuration has the switching magnet 25 on the inner rotor 30 side, the magnet can be discriminated by arranging the magnetic sensor 65 in the same manner.

In the example shown in FIG. 24, the lengths of the switching magnet 25 and the fixed magnet 35 are changed so that the magnetic sensor 65 can distinguish them, but the present invention is not limited to this form. For example, the magnetizing operation may be performed so as to temporarily demagnetize the switching magnet 25, the position of the switching magnet 25 may be determined based on the change, and then the switching magnet 25 may be returned to the original state.

It is also possible to discriminate the magnet by changing the magnetizing state such as the magnetizing amount and the magnetizing shape of the portion facing the magnetic sensor 65. Specifically, as shown in FIG. 26, a different pole may be formed in a part of the fixed magnet 35, and the magnetic sensor 65 may be arranged so as to face the different pole portion. Here, when the outer rotor 20 rotates, as shown in FIG. 27, the magnetic sensor 65 faces the different electrode portion of the fixed magnet 35. Therefore, the position of the fixed magnet 35 is specified, and the switching magnet 25 is used by the magnetic sensor 65. And the fixed magnet 35 can be discriminated.

Further, although the outer magnet 24 is composed of the switching magnet 25 and the fixed magnet 35, all of them may be composed of the switching magnet 25. In this case, the number of magnetic poles can be switched by reversing only the magnetic poles of an arbitrary half of the switching magnets 25. By doing so, magnetization switching can be performed without distinguishing between the switching magnet 25 and the fixed magnet 35.

<Motor deformation example 2>
FIG. 28 shows a modification 2 (motor 12B) of the motor 12. The outer rotor 20 of the motor 12B of the modification 2 is the same sequential type rotor as the above-described embodiment. The number of poles of the stator 60, the inner rotor 30, and the outer rotor 20 is the same (the ratio of magnetic poles is St: Mi: Mo = 3: 4: 4 or 2).

Therefore, 16 outer magnets 24 (all of which are switching magnets 25) are arranged on the inner surface of the rotor yoke 22 at regular intervals in the circumferential direction. However, in this motor 12B, the length of the switching magnet 25 in the circumferential direction is formed to be large.

Specifically, the circumferential length L1 of the switching magnet 25 is larger than the length L2 between two adjacent switching magnets 25, and the ratio L1: L2 is approximately 2: 1. The circumferential length L1 of the switching magnet 25 is also formed to be larger than the pitch P of the outer flange portion 61b of the two adjacent teeth 61, 61 facing the switching magnet 25.

By increasing the circumferential length L1 of the switching magnet 25 in this way, the torque when the outer rotor 20 is rotationally driven in the reciprocal rotation mode can be increased as compared with the motor 12 of the above-described embodiment. As a result, the stirring power in the washing process is improved, and the washing performance can be improved.

However, if the length L1 in the circumferential direction of the switching magnet 25 is increased in this way, the entire magnetic poles of the switching magnet 25 cannot be switched by one magnetization process. Therefore, in this case, it is necessary to perform the magnetization treatment a plurality of times as in the motor 12A of the modification 1.

However, if the magnetization process is performed while stopping the rotation of the outer rotor 20 as in the motor 12A of the first modification, it takes a lot of time to switch the number of magnetic poles. It is practically difficult to do during drive operation. Therefore, in the motor 12B of the modification 2, the outer rotor 20 is driven to rotate the inner rotor 30 based on the possibility of application of the motor 12A of the modification 1 described above so that the number of magnetic poles can be switched in a short time. The magnetizing process is performed multiple times while rotating with the rotation.

(Example of washing machine operation)
FIG. 29 shows a basic operation example of the washing machine 1 using the motor 12B. Prior to the operation of the washing machine 1, the user puts the laundry together with the detergent into the dehydration tub 11. The lid 3 is locked when closed. Then, when the washing course is instructed by the user's operation, the washing machine 1 starts operation.

When the operation of the washing machine 1 is started, water is supplied to the washing tub 10 and the dehydration tub 11 until a predetermined amount of water (usually, the degree to which the laundry is immersed in water) is reached (step S1). After that, the control device 15 controls the motor 12B and executes the first magnetization process (process of switching from the synchronous rotation mode to the reciprocal rotation mode) (step S2). After the first magnetization process, a process of magnetizing may be performed.

When the mode is switched to the reciprocal rotation mode by the first magnetization process, the washing process is performed (step S3). Specifically, when the motor 12B is driven by a predetermined drive current, the dehydration tub 11 and the pulsator 13 rotate in opposite directions for a predetermined time, and the laundry is agitated.

When the washing process is completed, the water is drained, and the control device 15 controls the motor 12B to execute a second magnetization process (a process of switching from the reciprocal rotation mode to the synchronous rotation mode) (step S4). After the second magnetization process, a process of magnetizing may be performed.

When the mode is switched to the synchronous rotation mode by the second magnetization process, the rinsing process is performed (step S5). In the rinsing process, as in the washing process, water is supplied to the washing tub 10 and the dehydration tub 11, and when a predetermined amount of water is stored, the motor 12B is driven by a predetermined drive current to drive the dehydration tub 11 and the dehydration tub 11. The pulsator 13 and the pulsator 13 rotate in the same direction at a low speed for a predetermined time, and the laundry is agitated. The rinsing process may be performed multiple times.

Then, when the rinsing process is completed, the dehydration process is performed (step S6). In the dehydration stroke, the dehydration tank 11 and the pulsator 13 are rotated at a higher speed than the rinsing stroke for a predetermined time. As a result, the water contained in the laundry is dehydrated by the action of centrifugal force and drained through the drain pipe 17. When the dehydration process is completed, the user is notified by a buzzer or the like that the operation is stopped, the lock of the lid 3 is released, and the operation of the washing machine 1 is completed.

(First magnetization treatment)
As described above, the first magnetization process is a process of switching from the synchronous rotation mode to the reciprocal rotation mode, and is devised so that the switching can be performed stably in a short time.

Specifically, in the first magnetization process, a magnetization current (anti-magnetization current) that reverses the magnetic poles is applied to the switching magnet 25 in a state where the motor 12B is driven in the synchronous rotation mode and the outer rotor 20 is rotating with the outer rotor 20. The supply process (anti-magnetization process) is executed a plurality of times.

Here, the state in which the outer rotor 20 is rotating with rotation means that when the inner rotor 30 (non-magnetized rotor) is rotationally driven by the supply of a predetermined drive current, the outer rotor is acted on by the drive current. 20 is rotating.

The first magnetization process is performed during the operation of the washing machine 1, in other words, during the period during which the motor 12B is being driven. Therefore, at the time of the first magnetization treatment, there is laundry in the dehydration tub 11 and water is stored in it. These loads are applied to the pulsator 13 to which the outer rotor 20 is connected. The same applies to the dehydration tank 11 to which the inner rotor 30 is connected.

Therefore, since a large moment of inertia acts on the outer rotor 20, it is possible to rotate the outer rotor 20 relatively stably for a long time even if it is rotated alongside. Since the demagnetization process can be performed using the long time, it can be stably performed even if the number of times is multiple.

On the other hand, a large torque is required to drive the outer rotor 20 to rotate.

When switching from the synchronous rotation mode to the reciprocal rotation mode, unlike the case of switching from the reciprocal rotation mode to the synchronous rotation mode, it is very difficult to switch stably. That is, if the magnetic poles of all the switching magnets 25 can be switched to an appropriate state by one diamagnetic treatment, there is no problem, but as described above, in the case of this motor 12B, the diamagnetic treatment is performed a plurality of times. There is a need.

In the middle of the diamagnetism process, a part of the switching magnet 25 is in a halfway state in which the magnetic poles are inverted. In that state, the magnetic force cancels out, so that the magnetic force of the switching magnet 25 weakens. When the magnetic force of the switching magnet 25 is weakened, even if a drive current is applied to drive the outer rotor 20 to rotate, only a weak torque is obtained. Therefore, if the rotation of the outer rotor 20 is stopped in such a state, the outer rotor 20 may not be rotationally driven. Therefore, it is necessary to perform diamagnetic processing while rotationally driving the inner rotor 30 which is the main rotor at a low speed, and to strengthen the magnetic force of the switching magnet 25 until the outer rotor 20 which is the sub-rotor cannot rotate around.

If the magnetism of the switching magnet 25 is in the weak reciprocal operation mode, the outer rotor 20 can be rotated around even in the synchronous operation mode. Therefore, in this motor 12B, the magnetization process is divided into a plurality of times so that the state of the reciprocal operation mode gradually becomes stronger, and the magnetic poles are gradually reversed while rotating around.

In the case of this motor 12B, the diamagnetic process is performed by repeating the process of supplying the diamagnetic current to different parts of the switching magnet 25 (partial diamagnetic process) a plurality of times. By doing so, the switching magnet 25 when the mode is switched to the reciprocal operation mode can be brought into a more appropriate magnetization state, and the induced voltage can be significantly increased.

The first magnetization process will be specifically described with reference to FIGS. 30 and 31. As shown in FIG. 31, when the first magnetization process is started, the control device 15 supplies a drive current to the motor 12B and drives the motor 12B in the synchronous rotation mode (step S10). The control device 15 supplies a controlled drive current to the motor 12B so that the rotation speed of the inner rotor 30 which is the main rotor rotates at a predetermined low rotation speed r1 (for example, 50 rpm). As a result, the outer rotor 20, which is a sub-rotor, also rotates in the same direction at substantially the same rotation speed as the inner rotor 30.

After that, the control device 15 detects the position of the outer rotor 20, specifically, the position of the switching magnet 25 to be switched (step S11). For detecting this position, various means such as the position sensor 64 and the magnetic sensor 65 described above, the Hall IC attached to the motor 12B, and the magnetic flux estimation from the current waveform of the motor 12B can be used.

Then, the control device 15 specifies the timing at which the outer rotor 20 is positioned at a predetermined magnetization position with respect to the teeth 61 to be magnetized during the accompanying rotation (step S12).

The control device 15 determines whether or not the rotation speed of the outer rotor 20 is a predetermined rotation speed r2 (for example, 5 rpm) or less during the accompanying rotation (step S13). If the rotation speed of the outer rotor 20 is not equal to or less than the predetermined rotation speed r2, the control device 15 supplies a pulsed diamagnetic current to the predetermined teeth 61 at a specified timing, and performs a partial diamagnetic treatment (partial). (Diamagnetic treatment) is performed (step S14).

FIG. 30A shows a state at the timing when the partial diamagnetic treatment is first performed on a certain switching magnet 25. The thin arrow in FIG. 30 represents the rotation of the outer rotor 20. The partial diamagnetic treatment is performed in order from one end (rear end in the rotation direction) in the circumferential direction of the switching magnet 25 toward the other end. A similar partial diamagnetization process is performed simultaneously or at different timings on the plurality of switching magnets 25.

At the timing when the outer rotor 20 that rotates with the rotation becomes the position (a) in FIG. 30, the control device 15 causes a diamagnetic current to a predetermined tooth 61 (in the example, a current that reverses from the north pole to the south pole). Is supplied, for example, for about 3 seconds. By doing so, as shown in FIG. 30B, the end portion of the switching magnet 25 is magnetized and the magnetic poles are inverted.

If the partial diamagnetic treatment is performed from the end of the switching magnet 25, since the switching magnet 25 does not exist on the rear side in the rotation direction, a strong magnetic force that slows down the accompanying rotation does not occur. Therefore, the magnetic field formed by the diamagnetic current supplied from the teeth 61 at that time can be used to accelerate the accompanying rotation. Therefore, the rotating rotation can be maintained for a longer time. On the other hand, if the partial diamagnetic treatment is performed from the middle portion of the switching magnet 25, since the switching magnet 25 exists on the rear side in the rotation direction, a strong magnetic force that slows down the accompanying rotation can be generated. Therefore, it is not possible to maintain the rotating rotation for a long time.

When the magnetized state of the switching magnet 25 changes due to the partial diamagnetic treatment, the position of the outer rotor 20 cannot be detected with high accuracy. Therefore, when the partial diamagnetic treatment is completed, the process returns to the front of step S11 again, and the position of the outer rotor 20 is detected again.

Then, the control device 15 specifies the timing at which the predetermined teeth 61 are positioned at the portion adjacent to the end where the magnetic pole of the switching magnet 25 is inverted, which is then magnetized. Subsequently, the control device 15 supplies a diamagnetic current to the predetermined teeth 61 at that timing. As a result, as shown in FIG. 30 (C), the magnetic pole of the portion adjacent to the end where the magnetic pole of the switching magnet 25 is inverted is inverted.

The control device 15 repeatedly performs such partial diamagnetism processing while the outer rotor 20 rotates around (steps S11 to S14). For example, the partial diamagnetic treatment is performed 10 to 30 times while rotating with the outer rotor 20. By doing so, as shown in (D) of FIG. 30, a partial diamagnetic treatment is performed on a wide region of each switching magnet 25, and the diamagnetic treatment is completed (step S15).

Since the magnetic poles of the switching magnet 25 are inverted step by step, unstable rotating rotation can be maintained for a long time while avoiding the risk of step-out. Since the partial diamagnetic treatment is continuously performed while rotating the outer rotor 20, the diamagnetic treatment can be completed in a short time. Since the time required for washing does not become excessively long, convenience is not impaired.

If most of the magnetic poles of the switching magnet 25 are inverted in this way, a strong torque can be obtained in the drive operation in the reciprocal rotation mode. Therefore, by supplying the drive current, the outer rotor 20 can be rotationally driven without stepping out. If the outer rotor 20 can be stably rotationally driven in the reciprocal rotation mode, partial diamagnetic processing of the magnetic poles of the unprocessed portion can be easily performed, and demagnetization of the switching magnet 25 can be easily performed, if necessary.

If the rotation speed of the outer rotor 20 becomes the rotation speed r2 or less during the partial anti-magnetization treatment, the rotating rotation of the outer rotor 20 may stop before the anti-magnetization processing is completed. If the rotating rotation of the outer rotor 20 is stopped while the magnetizing state of the switching magnet 25 is halfway in the reciprocal rotation mode, the required torque cannot be obtained even if the drive current is supplied, and the outer rotor is not obtained. There is a risk that the 2 cannot be driven to rotate.

Therefore, when the rotation speed of the outer rotor 20 becomes the rotation speed r2 or less (Yes in step S13) during the partial diamagnetism processing, the control device 15 forcibly forcibly performs the diamagnetism processing. To finish.

At that time, as the final partial diamagnetic treatment, a magnetization current longer than that of the normal partial diamagnetic treatment is supplied, and the magnetic poles in a wide range of the switching magnet 25 are inverted (step S16). By doing so, when the outer rotor 20 is rotationally driven in the reciprocal rotation mode, a relatively strong torque can be obtained, and the outer rotor 20 can be rotationally driven without stepping out.

Therefore, in this case, after the accompanying rotation of the outer rotor 20 is stopped, the outer rotor 20 is rotationally driven in the reciprocal rotation mode, and the partial diamagnetic processing of the portion where the magnetization is not completed is performed. If necessary, a magnetizing process is also performed, and an additional magnetization process is performed so that the magnetized state of each switching magnet 25 matches the reciprocal rotation mode.

(Second magnetization treatment)
As described above, the second magnetization process is a process of switching from the reciprocal rotation mode to the synchronous rotation mode. Unlike the first magnetization process, the second magnetization process can be easily magnetized. That is, since the magnetic poles of each switching magnet 25 are switched in the direction of rotation by driving in the synchronous rotation mode, the magnetizing state of the reciprocal rotation mode becomes weaker as the magnetic poles are switched (the magnetization state of the synchronous rotation mode is stronger). Become). Therefore, even if the outer rotor 20 is stopped in that state, the outer rotor 20 can be easily rotationally driven by driving in the synchronous operation mode.

The second magnetization process will be specifically described with reference to FIG. 32. The main steps of the second magnetization treatment are the same as those of the first magnetization treatment. The control device 15 repeatedly performs a partial diamagnetism process for switching from the reciprocal rotation mode to the synchronous rotation mode while the outer rotor 20 is rotating around. Therefore, the same reference numerals will be used for the same steps, the description thereof will be omitted, and different steps will be described.

In the first magnetization treatment, when the rotation speed of the outer rotor 20 became the rotation speed r2 or less, the diamagnetic treatment was forcibly terminated once, but in the second magnetization treatment, the outer rotor 20 stopped in the middle. However, since the outer rotor 20 can be easily rotationally driven, it is not necessary.

Therefore, when the rotation speed of the outer rotor 20 becomes the rotation speed r2 or less during the partial diamagnetism processing, the control device 15 returns to the front of step S10 and supplies the drive current again to the rotation speed. (Yes in step S13), and then the partial diamagnetic process may be restarted.

Switching from the reciprocal rotation mode to the synchronous rotation mode does not have problems such as torque drop and step-out unlike the reciprocal rotation mode. Therefore, the second magnetization process can be performed relatively freely. Therefore, in the second magnetization treatment, the portion where the partial diamagnetization treatment is performed, the order in which the partial diamagnetization treatment is performed, and the like can be appropriately changed according to the specifications.

(Application example 1 of partial diamagnetic treatment)
FIG. 33 shows an application example 1 of the partial diamagnetic treatment of the motor 12B of the modification 2.

In the above-mentioned partial anti-magnetization treatment, the length of the anti-magnetization current supplied by each partial anti-magnetization treatment is substantially constant, whereas in Application Example 1, the anti-magnetization treatment in which the supply time of the anti-magnetization current is long is long. (Long magnetization processing) and anti-magnetization processing (short magnetization processing) in which the supply time of the anti-magnetization current is short are included, and the long magnetization processing is performed on the intermediate portion side in the circumferential direction of the switching magnet 25 rather than the short magnetization treatment.

As shown in FIG. 33A, in the partial demagnetization treatment of Application Example 1, the first partial demagnetization treatment is the same as the above-mentioned partial demagnetization treatment, that is, the end portion of the switching magnet 25 in the circumferential direction. Performed on the side (corresponding to short magnetization treatment). Then, on the intermediate portion side in the circumferential direction of the switching magnet 25 after the second time, as shown in FIG. 33 (B), the supply time of the diamagnetic current is lengthened, and the region of the switching magnet 25 is relatively wide. The magnetic poles are reversed (corresponding to long magnetization processing).

In the short magnetization process, a demagnetization current (triangular wave antimagnetization current) having a triangular current waveform with a peak is supplied, and in the long magnetization process, a demagnetization current (trapezoidal wave) having a trapezoidal current waveform with an extended peak is supplied. Anti-magnetization current) is supplied. The maximum value of the current is the same for both. In the partial anti-magnetization process described above, the control device 15 performs the partial anti-magnetization process with a plurality of triangular wave anti-magnetization currents, whereas in the partial anti-magnetization process of Application Example 1, a plurality of triangular wave anti-magnetization currents and one or more are performed. Partial anti-magnetization processing is performed by combining the trapezoidal wave anti-magnetization currents of.

On the intermediate portion side in the circumferential direction of the switching magnet 25, even if the region to be partially demagnetized is widened in this way, the target switching magnet 25 can be reliably partially demagnetized. Can be reduced.

In particular, as described above, the partial diamagnetic treatment of Application Example 1 is a partial diamagnetic treatment at the time of switching from the synchronous rotation mode to the reciprocal rotation mode, and the rotating rotation of the outer rotor 20 may be stopped. Can be used effectively in some cases.

(Application example 2 of partial diamagnetic treatment)
FIG. 34 shows an application example 2 of the partial diamagnetic treatment of the motor 12B of the modification 2.

In the above-mentioned partial anti-magnetization treatment, the strength of the anti-magnetization current supplied by each partial anti-magnetization treatment is substantially constant, whereas in Application Example 2, the anti-magnetization treatment (strong magnetization) in which the anti-magnetization current is large is large. The process) and the anti-magnetization process (weak magnetization process) in which the anti-magnetization current is small are included, and the weak magnetization process is performed on the end side in the circumferential direction of the switching magnet 25 rather than the strong magnetization process.

In both the weak magnetization treatment and the strong magnetization treatment, a demagnetization current (triangular wave antimagnetization current) having a triangular current waveform having a peak is supplied. The current supply times are the same for both, and they differ in that the peak of the strong magnetization treatment is higher (larger) than the peak of the weak magnetization treatment.

As described above, in the motor 12B of the modification 2, since the length of the switching magnet 25 in the circumferential direction is large, the tooth 61 that performs the magnetization treatment performs diamagnetic treatment on one end of the switching magnet 25. At times, as shown in FIG. 35, the teeth 61 adjacent to the teeth 61 will be located near the other end of the switching magnet 25.

Then, in order to perform diamagnetic processing on one end of the switching magnet 25, for example, when a diamagnetic current for switching the N pole to the S pole is supplied to the teeth 61, the action of the diamagnetic current causes the other end of the switching magnet 25. The ends of the magnet tend to be magnetized to the north pole side. Therefore, if the other end of the switching magnet 25 is N pole, it will be magnetized, and there is no problem, but if the other end of the switching magnet 25 is S pole, it will be demagnetized. It will be disadvantageous.

Therefore, as shown in FIG. 34 (A), even in the partial diamagnetic treatment of Application Example 2, the first partial diamagnetic treatment is performed in the circumferential direction of the switching magnet 25, as in the above-mentioned partial diamagnetic treatment. Performed on the end side (corresponding to weak magnetization treatment). Then, on the intermediate portion side in the circumferential direction of the switching magnet 25 after the second time, the diamagnetic current is increased as shown in FIG. 34 (B), and the magnetic pole in the region of the intermediate portion of the switching magnet 25 is strongly strengthened. Invert (corresponds to strong magnetization treatment).

On the intermediate portion side in the circumferential direction of the switching magnet 25, even if the partial diamagnetic treatment is strengthened in this way, the other portions are not adversely affected. Since the magnetic force of the switching magnet 25 becomes large, the induced voltage increases and a high torque can be obtained, so that the outer rotor 20 can be stably rotationally driven.

(Application example of diamagnetic treatment)
In the motor 12B of the modification 2 described above, an example in which the switching magnet 25 is partially diamagnetically processed is shown, but while the switching magnet 25 is rotating around, each of the switching magnets 25 is diamagnetic stepwise. Magnetization treatment may be performed.

Specifically, as shown in each step (A), (B), and (C) of FIG. 36, the entire magnetic pole of one target switching magnet 25 is inverted by one diamagnetic treatment. .. The number of magnetic poles is switched by performing the process a plurality of times during the accompanying rotation.

<Motor deformation example 3>
FIG. 37 is a plan sectional view showing the configuration of the motor 12C of the modified example 3. The inner rotor 30 is an embedded SPM type rotor, and 32 inner magnets 34 are arranged so that S poles and N poles are alternately arranged in the circumferential direction, and are embedded in the inner peripheral wall portion 32. There is. The inner magnets 34 are all composed of fixed magnets 35.

The outer rotor 20 is an SPM type rotor, and 32 outer magnets 24 are arranged so that S poles and N poles are alternately arranged in the circumferential direction, and are fixed to the inner surface of the rotor yoke 22. The outer magnet 24 is composed of a switching magnet 25 and a fixed magnet 35, but the arrangement thereof is the same as that of the motor 12A of the first modification, and thus the description thereof will be omitted.

<Motor deformation example 4>
FIG. 38 is a plan sectional view showing the configuration of the motor 12D of the modified example 4. The inner rotor 30 is an embedded SPM type rotor, and 32 inner magnets 34 are arranged so that S poles and N poles are alternately arranged in the circumferential direction, and are embedded in the inner peripheral wall portion 32. There is. The inner magnets 34 are all composed of fixed magnets 35.

The outer rotor 20 is a concave rotor, and 16 outer magnets 24 are arranged so that S poles are lined up at intervals in the circumferential direction, and are fixed to the inner surface of the rotor yoke 22. The outer magnet 24 is all composed of a switching magnet 25, and the number of magnetic poles of the outer rotor 20 can be switched between 16 poles and 32 poles by reversing the magnetic poles of the switching magnet 25. Since the reversing operation of the magnetic poles of the switching magnet 25 is the same as that of the motor 12 of the embodiment, the description thereof will be omitted.

<Motor deformation example 5>
FIG. 39 is a plan sectional view showing the configuration of the motor 12E of the modified example 5. The teeth 61 are provided with width details 67 so that the width of the teeth 61 on the outer rotor 20 side having the switching magnet 25 is narrower than the width of the teeth 61 on the inner rotor 30 side. The width detail 67 is formed so that the width of the teeth 61 is tapered toward the outer rotor 20 side.

In this way, the magnetic flux density can be increased by providing the teeth 61 with the width details 67 and narrowing the width of the teeth 61 on the outer rotor 20 side. That is, the magnetization magnetic flux generated by the current flowing through the coil 63 can be concentrated and flowed toward the switching magnet 25, and the magnetic pole reversal of the switching magnet 25 can be stably performed with a small current. The shape of the width detail 67 is not particularly limited, and may be, for example, a stepped shape in which the teeth width on the outer rotor 20 side of the teeth 61 is narrowed.

Further, the coil 63 wound around the teeth 61 has a larger number of turns on the outer rotor 20 side having the switching magnet 25 than on the inner rotor 30 side. As a result, the magnetic flux on the switching magnet 25 side can be concentrated more than on the opposite side.

Further, the angle width of the tip portion of the teeth 61 is smaller in the angle width B on the outer rotor 20 side having the switching magnet 25 than in the angle width A on the inner rotor 30 side (B <A). As a result, the magnetic flux on the switching magnet 25 side can be concentrated more than on the opposite side.

Further, even if the angle width of the tip portion of the teeth 61 is the same on the outer rotor 20 side and the inner rotor 30 side, the cross-sectional area of the tip portion of the teeth 61 is larger on the outer rotor 20 side having the switching magnet 25. The same function can be obtained by making the inner rotor 30 smaller than the inner rotor 30 side.

Specifically, as shown in FIG. 40, a groove portion 68 extending in the axial direction is formed on the surface of the tip portion of the teeth 61 facing the outer rotor 20. Two groove portions 68 are formed with an interval in the circumferential direction. In this way, by making the air gap area substantially facing the outer magnet 24 at the tip of the teeth 61 excluding the groove portion 68 smaller than the air gap area on the inner rotor 30 side, the magnetic flux on the switching magnet 25 side. Can be more concentrated than on the other side.

<Others>
In the disclosed embodiment, the configuration in which the coil 63 of the stator 60 is used as the magnetic pole number switching unit and the magnetic pole of the switching magnet 25 is inverted by supplying a magnetization current to the coil 63 has been described. Separately from the coil 63, a magnetizing coil for supplying a magnetization current to the switching magnet 25 to invert the magnetic poles may be provided.

Further, although the inverter for the motor is used for the control device 15 that supplies the magnetization current to the coil 63, for example, another dedicated control device may be used.

The rotation drive method of the outer rotor 20 and the inner rotor 30 can be arbitrarily selected from a rectangular wave energization method, a sine wave drive, vector control, and the like.

The number of poles of the stator 60, the outer rotor 20, and the inner rotor 30 can be appropriately set according to the specifications of the motor. For example, when the number of magnetic poles on the inner rotor 30 side is 2N (N is a natural number of 2 or more), the magnetic poles on the outer rotor 20 side may be switched between 2N and N.

The configuration in which the inner rotor 30 on the high-speed rotation side is connected to the dehydration tank 11 and the outer rotor 20 on the low-speed rotation side is connected to the pulsator 13 has been described. However, the inner rotor 30 is connected to the dehydration tank 11 and the outer rotor 20 is connected to other parts. By connecting to a rotating shaft having the above functions, it is possible to improve commerciality such as dehydration performance and washing performance.

Although the number of magnetic poles of the outer rotor 20 can be switched by providing the outer rotor 20 with the switching magnet 25, the number of magnetic poles of the inner rotor 30 may be switched by providing the inner rotor 30 with the switching magnet 25.

The washing machine is not limited to the vertical type, and may be a drum type. In that case, for example, the dehydration tank 11 corresponds to a basket, and the pulsator 13 corresponds to a stirring blade arranged inside the basket.

12 Motor 15 Control device (control unit)
20 Outer rotor (second rotor)
25 Switching magnet 30 Inner rotor (1st rotor)
35 Fixed magnet 60 Stator 61 Teeth (switching number of magnetic poles)
63 Coil (switching number of magnetic poles)
64 Position sensor (magnet discriminator)
65 Magnetic sensor (magnet discriminator)

Claims (23)

It is a motor for drive operation,
One stator, and an inner rotor and an outer rotor that are independently rotatably arranged inside and outside the stator.
A control unit for controlling the rotational drive and magnetization processing of the inner rotor and the outer rotor is provided.
During the drive operation, the control unit switches the magnetic poles of the inner rotor and the magnetization-compatible rotor corresponding to the magnetization of at least one of the outer rotors by magnetization processing, so that the inner rotor and the outer rotor are switched. The rotor is configured to be switchable between a synchronous rotation mode in which the rotors rotate in the same direction and a reciprocal rotation mode in which the rotors rotate in opposite directions.
The magnetization-compatible rotor has a plurality of switching magnets capable of reversing the magnetic poles by supplying a magnetization current.
By supplying the magnetization current to the switching magnet at a predetermined timing, the stator switches between the synchronous rotation mode and the reciprocal rotation mode.
The switching from the synchronous rotation mode to the reciprocal rotation mode is performed a plurality of times in a state where the magnetization-compatible rotor is rotating with the rotation, and a demagnetization process of supplying a demagnetization current that reverses the magnetic poles to the switching magnet is executed. Motor made by doing. In the motor according to claim 1,
The stator faces the magnetization-compatible rotor in the radial direction, and has a plurality of magnetization-compatible teeth that supply a driving current and the magnetization current to the switching magnet.
A motor in which the length of the switching magnet in the circumferential direction is larger than the pitch of the magnetization-compatible teeth. In the motor according to claim 2,
A motor in which the diamagnetic treatment is performed by repeating the partial diamagnetic treatment for supplying the diamagnetic current to different parts of the switching magnet a plurality of times. In the motor according to claim 3,
A motor in which the partial diamagnetic treatment is performed from one end of the switching magnet in the circumferential direction. In the motor according to claim 3 or 4.
A motor in which the partial diamagnetic treatment is performed while accelerating the rotating rotation of the magnetization-compatible rotor. In the motor according to claim 3 or 4.
The partial anti-magnetization process includes a long magnetization process in which the anti-magnetization current supply time is long and a short magnetization process in which the anti-magnetization current supply time is short.
A motor in which the long magnetization treatment is performed on the intermediate portion side in the circumferential direction of the switching magnet rather than the short magnetization treatment. In the motor according to claim 6,
A motor that performs the long magnetization process and ends the diamagnetic process when the control unit determines that the accompanying rotation of the magnetization-compatible rotor is a predetermined rotation speed or less. In the motor according to any one of claims 3 to 7.
The partial demagnetization treatment includes a strong magnetization treatment having a large antimagnetization current and a weak magnetization treatment having a small antimagnetization current.
A motor in which the weak magnetization treatment is performed on the end side in the circumferential direction of the switching magnet rather than the strong magnetization treatment. The motor according to any one of claims 1 to 8.
A motor for a washing machine used to drive the stirring member of the washing machine and the dehydration tub. A motor including an annular stator and a first rotor and a second rotor that can rotate independently of the stator.
At least one of the first rotor and the second rotor has a plurality of switching magnets whose magnetic poles are inverted when a magnetization current is supplied and a plurality of fixed magnets whose magnetic poles are not inverted .
A magnetic pole number switching unit that performs a magnetization operation for switching the number of magnetic poles by reversing the magnetic poles of the rotor having the switching magnet by supplying a magnetization current.
A control unit that controls the magnetization operation of the magnetic pole number switching unit to rotate the first rotor and the second rotor in a plurality of rotation modes .
A magnet discriminating unit for discriminating between the switching magnet and the fixed magnet is provided.
The control unit is configured to perform the magnetization operation in a plurality of times while changing the relative position between the rotor and the number of magnetic poles switching unit when switching the number of magnetic poles of the rotor having the switching magnet. Being done
The control unit further performs the magnetization operation so as to temporarily demagnetize the switching magnet, and the magnet discriminating unit detects the demagnetized magnet to obtain the switching magnet and the fixed magnet. A motor that is configured to discriminate . In the motor according to claim 10,
The control unit is a motor that performs all of the magnetization operations performed in a plurality of times while the rotor having the switching magnet is rotating. In the motor according to claim 10,
The control unit is a motor that performs the magnetization operation while the rotation of the rotor having the switching magnet is stopped or during low-speed rotation in which the rotation speed of the rotor is lower than a predetermined rotation speed. In the motor according to claim 12,
The control unit performs the magnetization operation at least once while the rotation of the rotor having the switching magnet before starting the magnetization operation is stopped, and then the rotor and the magnetic pole number switching unit are relative to each other. A motor that performs the magnetization operation for the remaining number of times while changing the position. In the motor according to any one of claims 10 to 13.
The control unit is a motor that performs the magnetization operation during a synchronous rotation mode in which the first rotor and the second rotor are rotated in the same direction. In the motor according to any one of claims 10 to 14,
The control unit is a motor that performs the magnetization operation while switching the energization phase according to the movement of the rotor while the rotor having the switching magnet is rotating. In the motor according to claim 15,
The control unit is a motor that performs the magnetization operation while switching the energization phase according to the movement of the rotor by setting the initial phase of the rotor having the switching magnet as the initial value and adding the magnet movement amount. In the motor according to claim 10,
The magnet discrimination unit is composed of a position sensor arranged so as to face the switching magnet.
The switching magnet is a motor in which a portion facing the position sensor is arranged in a state different from that of the fixed magnet. In the motor according to claim 10,
The magnet discrimination unit is composed of a magnetic sensor arranged so as to face the switching magnet.
The switching magnet is a motor in which the shape of the portion facing the magnetic sensor is different from that of the fixed magnet. In the motor according to claim 10,
The magnet discrimination unit is composed of a magnetic sensor arranged so as to face the switching magnet.
The switching magnet is a motor in which the magnetized state of the portion facing the magnetic sensor is different from that of the fixed magnet. A motor including an annular stator and a first rotor and a second rotor that can rotate independently of the stator.
At least one of the first rotor and the second rotor has a plurality of switching magnets whose magnetic poles are inverted when a magnetization current is supplied and a plurality of fixed magnets whose magnetic poles are not inverted .
A magnetic pole number switching unit that performs a magnetization operation for switching the number of magnetic poles by reversing the magnetic poles of the rotor having the switching magnet by supplying a magnetization current.
A control unit that controls the magnetization operation of the magnetic pole number switching unit to rotate the first rotor and the second rotor in a plurality of rotation modes is provided.
The control unit is configured to perform the magnetization operation in a plurality of times while changing the relative position between the rotor and the number of magnetic poles switching unit when switching the number of magnetic poles of the rotor having the switching magnet. ,
A motor in which the control unit further controls the rotational operation of the first rotor and the second rotor based on the position of the fixed magnet . In the motor according to any one of claims 10 to 20,
The magnetic pole number switching unit is a tooth of the stator, and is
The coil wound around the teeth is a motor having a larger number of turns on the rotor side having the switching magnet than on the other rotor side. In the motor according to any one of claims 10 to 21,
The magnetic pole number switching unit is a tooth of the stator, and is
The motor is provided with width details such that the width of the teeth on the rotor side having the switching magnet is narrower than the width of the teeth on the other rotor side. The motor according to any one of claims 10 to 22.
The magnetic pole number switching unit is a tooth of the stator, and is
A motor in which the angular width or cross-sectional area of the tip of the tooth is smaller on the rotor side having the switching magnet than on the other rotor side.

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