JP6965677B2 - Rotating machine and rotating machine system - Google Patents

Description

The present invention relates to a surface magnet type rotary electric machine and a rotary electric machine system.

A surface magnet type motor (SPM motor) is known as a rotary electric machine using a permanent magnet, and the surface magnet type motor has become widespread as a high-performance motor because it can utilize the magnetization torque distributed over the entire magnetic pole by the permanent magnet. There is.

On the other hand, a magnetic circuit using a Halbach Array is known as a technique for optimizing the direction of magnetic poles. For example, in Patent Document 1, as a rotor of a wheel-driven rotary electric machine, magnetic pole magnets that are alternately arranged at predetermined pitches in the circumferential direction and magnetized in the substantially radial direction are provided between the magnetic pole magnets, respectively, and have a substantially circumferential circumference. A configuration using a field magnet having a yoke magnet magnetized in the direction is disclosed.

Japanese Unexamined Patent Publication No. 2006-187116

By the way, the surface magnet type motor has a field magnet in which a permanent magnet is attached to the surface of the rotor, and the magnetic resistance seen from the armature side is as large as that of air. Therefore, in general, it is difficult to control the field magnet from the armature side with a rated level current, and no examples have been studied from the viewpoint of practical technology. Therefore, the existing surface magnet type motor has problems such as a decrease in output at a high speed at which the induced voltage becomes high and an increase in iron loss of the armature. It is considered that the rotary electric machine adopting the Halbach array described above cannot realize the variable field magnetic field.

The present invention has been made in view of the above problems, and a main object thereof is to realize a variable field magnetic flux by suitably changing the field magnetic flux generated by a rotor in a surface magnet type rotary electric machine. be.

Hereinafter, means for solving the above problems and their actions and effects will be described. In the following, for the sake of easy understanding, the reference numerals of the corresponding configurations in the embodiment of the invention are appropriately shown in parentheses or the like, but the present invention is not limited to the specific configurations shown in the parentheses or the like.

The first means is
Rotor (12) rotatably supported and
An armature (13) that is coaxially arranged with the rotor and is wound with an armature winding (23) that is energized with a multi-phase alternating current.
It is a rotating electric machine (10) on the permanent magnet side equipped with
The rotor
A plurality of permanent magnets (32) provided at positions separated from each other in the circumferential direction so that the magnetization direction is the radial direction and the poles facing the armature are alternately N poles and S poles.
A yoke member (34) made of an iron core material, connecting the peripheral side surfaces of the permanent magnets between the permanent magnets adjacent to each other in the circumferential direction, and connecting the plurality of permanent magnets in an annular shape.
Have and
By controlling the phase of energization in the armature winding, it is possible to change the strength of the field magnetic flux from the permanent magnet to the armature.

In the rotating electric machine having the above configuration, the rotors are separated from each other in the circumferential direction so that the magnetization direction (direction of the magnetic pole) is the radial direction and the poles facing the armature are alternately N poles and S poles. It has a plurality of permanent magnets provided at the positions. The plurality of permanent magnets are connected (bridged) to each other in the circumferential direction of the permanent magnets by a yoke member which is an iron core, and are connected in an annular shape. Here, the permanent magnet has a configuration in which a field magnetic flux flows through the radial end surface on the armature side and the circumferential side surface on the armature member side, and when the magnetomotive force is generated by the energization of the armature winding, the magnetic flux is generated. The distribution of the field magnetic flux generated by the permanent magnets differs depending on the direction of the magnetomotive force and the magnetic poles of each permanent magnet. In this case, the field magnetic flux flowing through the circumferential side surfaces of the adjacent permanent magnets can be suitably changed. As a result, in the surface magnet type rotary electric machine, the field magnetic flux generated by the rotor can be suitably changed to realize the variable field magnetic flux.

The first means described above will be supplementarily described with reference to FIG. In FIG. 12, the permanent magnet 101 and the yoke member 102 (iron core) are linearly developed and shown in the rotor, the upper side is the armature side, and the lower side is the opposite side of the armature. When an electric current is passed through the armature winding, a magnetomotive force is generated in a loop shape as shown by the broken line. The position where the magnetomotive force is generated in the circumferential direction of the rotor, that is, the direction of the magnetomotive force with respect to each permanent magnet 101 depends on the energization phase of the armature winding. Here, in the permanent magnet 101, as shown in FIG. 12A, the direction of the magnetic flux of the magnet (the direction of N → S of the magnet) and the direction of the motive force of the armature winding are the same, and ( As shown in b), the direction of the magnet magnetic flux and the direction of the electromotive force of the armature winding may be opposite, and in the case of (b), the field magnetic flux is weakened. Further, in the yoke member 102, the directions of the internal magnetic fluxes are different between the side closer to the armature and the side farther from the armature in the radial direction according to the directions of the magnetic fluxes of the two permanent magnets 101 adjacent to the yoke member 102. In such a case, as shown in FIGS. 12A and 12B, the strength of the field magnetic flux differs depending on the magnetomotive force of the armature winding, that is, the energization phase of the armature winding. .. As a result, a variable field rotating electric machine can be realized.

Here, the difference from the technique of arranging magnets by the Halbach array will be described. The Halbach array is a special array of permanent magnets for the magnetic flux concentration effect, which was devised by Klaus Halbach, a physicist at the Lawrence Berkeley Laboratory in the United States, for the purpose of converging the beam of the particle accelerator in the 1980s. In recent years, it is a technology that is increasingly used in fields such as permanent magnet type MRI, electric motors, linear motors, magnetic levitation type railways, and undulators for generating free electron lasers.

One of the famous features of the Halbach array is the one-sided concentration phenomenon of magnetic flux shown in FIG. In FIG. 13, the polar magnets 111 and the yoke magnets 112 are alternately arranged in a relationship in which the magnetization directions are orthogonal to each other. The magnetic flux is concentrated on either the upper or lower side of the array. At this time, if the direction of magnetization of the yoke magnet 112 is reversed as shown in FIGS. 13 (a) and 13 (b), the side where the magnetic flux is concentrated is reversed. In this way, the magnetic flux can be concentrated only by the method of arranging the permanent magnets, and it is known as a method of concentrating the magnetic field without using an iron piece or a coil.

In the configuration of FIG. 12 (rotary electric machine in the first means), the magnet between the poles (yoke magnet 112) in FIG. 13 is changed to a yoke member 102 which is an iron core. In the Halbach array, the yoke is a magnet, and it has its own magnetomotive force (magnetization), but in the case of an iron core, it does not. Therefore, as it is, it is only a means for short-circuiting the polar magnet on the side surface. In this regard, in the configuration of FIG. 12, two adjacent permanent magnets 101 are short-circuited on the side surface by the yoke member 102 (iron core), and in such a configuration, the field magnetic flux is controlled by the phase control of the energization in the armature winding as described above. It is possible to change the strength of.

In the second means, a plurality of the yoke members are provided in the radial direction between the permanent magnets adjacent to each other in the circumferential direction.

A plurality of yoke members are provided in the radial direction between the permanent magnets adjacent to each other in the circumferential direction. Here, in the configuration in which the yoke member is connected to the circumferential side surface of the permanent magnet, the magnetic flux circulates in the vicinity of the side surface of the magnet, and the magnetic flux constantly leaks. However, by providing the yoke member in a plurality of parts in the radial direction, it is possible to suppress magnetic flux leakage on the side surface of the magnet.

It should be noted that the plurality of yoke members may be separated into a plurality of members at least on or near the side surface in the circumferential direction, and for example, a bridging portion may be provided in an intermediate portion between adjacent permanent magnets in the yoke member. ..

In the third means, the yoke member has a shape in which an intermediate portion in the circumferential direction is concave in the radial direction with respect to the end portion of the yoke connected to the side surface of the permanent magnet on the peripheral surface on the armature side. ..

The yoke member has a shape in which the middle portion in the circumferential direction is recessed in the radial direction on the peripheral surface on the armature side. Therefore, the flow of magnetic flux between the permanent magnets arranged in the circumferential direction and the yoke member can be promoted, and the leakage flux from the yoke member to the armature can be reduced. This makes it possible to improve energy efficiency.

In the fourth means, a yoke support portion (35) extending to the opposite side of the armature is connected between the permanent magnets adjacent to each other in the circumferential direction to the yoke member, and the yoke member is connected to the yoke member. The yoke support portion is integrally connected by the connecting portion (33).

A yoke support portion extending in the direction opposite to the armature is connected to the yoke member between permanent magnets adjacent to each other in the circumferential direction, and the yoke support portion for each yoke member is integrally connected by the connecting portion. Thereby, in the configuration in which the yoke members are provided between the permanent magnets adjacent to each other in the circumferential direction, the plurality of permanent magnets and the plurality of yoke members can be suitably coupled while being arranged in an annular shape. In this case, since the yoke support portion is connected to the opposite side of the armature between adjacent permanent magnets, magnetic flux leakage through the yoke support portion is suppressed.

The fifth means is a rotary electric machine system including a rotary electric machine and a control unit (42) for performing phase control of energization in the armature winding, and the control unit controls the phase of the armature current. Control is performed to weaken the field magnetic flux by advancing in the rotational direction with respect to the q-axis of the rotor, and to strengthen the field magnetic flux by delaying the phase of the armature current in the rotational direction with respect to the q-axis of the rotor. do.

The control unit advances or delays the phase of the armature current in the rotational direction with respect to the q-axis of the rotor to weaken or strengthen the field magnetic flux. Thereby, the torque and the like can be controlled as desired.

Vertical sectional view of a rotary electric machine. Cross-sectional view showing a rotor and an armature. The figure which shows the main part of a rotor in an enlarged manner. The figure which shows the relationship between the direction of the excitation by an armature and the magnetic field distribution. Explanatory drawing of consideration using an equivalent circuit about the rotary electric machine of an embodiment. Explanatory drawing of consideration using an equivalent circuit about a general surface magnet type motor. Explanatory drawing that a double-layer yoke has an advantage over a single-layer yoke. The figure which shows the simulation result of the magnetic flux distribution in the state of torque output. The figure which shows the simulation result of the finite element method magnetic field analysis. The figure which shows the magnetic flux density distribution at the time of the maximum torque and the time of the minimum magnetic flux by the finite element method magnetic field analysis simulation. The cross-sectional view which shows the rotor and the armature in another example. The figure which shows the relationship between the direction of the excitation by an armature and the magnetic field distribution. The figure which shows the magnetic field concentration phenomenon in the Halbach array.

Hereinafter, embodiments will be described with reference to the drawings. The rotary electric machine in this embodiment is used, for example, as a vehicle power source. However, the rotary electric machine can be widely used for industrial use, vehicle use, home appliance use, OA equipment use, game machine use, and the like. In each of the following embodiments, parts that are the same or equal to each other are designated by the same reference numerals in the drawings, and the description thereof will be incorporated for the parts having the same reference numerals.

The rotary electric machine 10 according to the present embodiment is a surface magnet type synchronous multi-phase AC motor having an inner rotor structure (adduction structure). The outline of the rotary electric machine 10 is shown in FIGS. 1 and 2. FIG. 1 is a vertical cross-sectional view of the rotary electric machine 10 in a direction along the rotation axis 11, and FIG. 2 is a cross-sectional view of the rotor 12 and the armature 13 in a direction orthogonal to the rotation axis 11. In the following description, the direction in which the rotating shaft 11 extends is the axial direction, the direction in which the rotating shaft 11 extends radially is the radial direction, and the direction in which the rotating shaft 11 extends in a circumferential shape is the circumferential direction.

The rotary electric machine 10 includes a rotor 12 fixed to a rotary shaft 11, an armature 13 provided at a position surrounding the rotor 12, and a housing 14 for accommodating the rotor 12 and the armature 13. .. The rotor 12 and the armature 13 are arranged coaxially. The housing 14 has a pair of bottomed cylindrical housing members 14a and 14b, and the housing members 14a and 14b are integrated by fastening bolts 15 in a state where the housing members 14a and 14b are joined to each other at the openings. Bearings 16 and 17 are provided in the housing 14, and the rotating shaft 11 and the rotor 12 are rotatably supported by the bearings 16 and 17.

As shown in FIG. 2, the armature 13 includes an annular armature core 22 having a plurality of slots 21 in the circumferential direction, and three phases (U phase, V) wound around each slot 21 of the armature core 22. It is provided with an armature winding 23 (phase, W phase). The armature core 22 is configured by laminating a plurality of annular electromagnetic steel sheets in the axial direction and fixing them by caulking or the like. The armature core 22 has an annular yoke 24 and a plurality of teeth 25 protruding inward in the radial direction from the yoke 24 and arranged at a predetermined distance in the circumferential direction, and a slot 21 is provided between the adjacent teeth 25. Is formed. Each tooth 25 is provided at equal intervals in the circumferential direction.

Two slots 21 are provided side by side for each phase of the armature winding 23. That is, the armature core 22 is formed with two U-phase slots, two V-phase slots, and two W-phase slots repeatedly arranged in the circumferential direction. An armature winding 23 is wound around each slot 21 so as to be wound around the teeth 25. The armature winding 23 is configured, for example, by joining a plurality of conductor segments to each other.

The rotor 12 has a rotor core 31 fixed to the rotating shaft 11 and a plurality of permanent magnets 32 held by the rotor core 31. The rotor core 31 connects (bridges) the peripheral side surfaces of the permanent magnets 32 between the cylindrical central fixing portion 33 fixed to the rotating shaft 11 and the permanent magnets 32 adjacent to each other in the circumferential direction. ), And a rotor yoke 34 that connects a plurality of permanent magnets 32 in an annular shape, and a plurality of yoke support portions 35 that extend radially around the rotation shaft 11 and connect the central fixing portion 33 and the rotor yoke 34. .. The rotor yoke 34 is made of an iron core material, which corresponds to a "yoke member". In the present embodiment, the central fixing portion 33, the rotor yoke 34, and the yoke supporting portion 35 are integrally formed of an electromagnetic steel plate, and a plurality of electromagnetic steel plates are laminated in the axial direction and fixed by caulking or the like to rotate. The child core 31 is configured.

A plurality of permanent magnets 32 are assembled to the rotor yoke 34 at predetermined intervals. Specifically, the plurality of permanent magnets 32 are arranged by the rotor yoke 34 in the circumferential direction at the same intervals as the pitch at which the armature windings 23 having the same phase are wound on the armature 13. Further, each permanent magnet 32 is provided at a position separated from each other in the circumferential direction so that the magnetization direction (direction of the magnetic pole) is the radial direction and the poles facing the armature 13 are alternately N poles and S poles. Has been done.

Further, as shown in FIG. 3, the rotor yoke 34 is provided separately in the inner and outer directions in the radial direction, and the outer peripheral side is the outer peripheral side yoke 34a and the inner peripheral side is the inner peripheral side yoke 34b. Both the outer peripheral side yoke 34a and the inner peripheral side yoke 34b are provided so as to extend in the circumferential direction from the circumferential side surface of the permanent magnet 32, and a space portion is provided between them. A bridging portion connecting both yokes 34a and 34b may be provided in the space between the outer peripheral side yoke 34a and the inner peripheral side yoke 34b. The outer peripheral side yoke 34a is provided on the side closer to the armature 13 in the radial direction, and the inner peripheral side yoke 34b is provided on the side farther from the armature 13 in the radial direction. The outer peripheral side yoke 34a and the inner peripheral side yoke 34b form two magnetic circuits separated in the radial direction. The radial width L1 of the outer peripheral side yoke 34a and the radial width L2 of the inner peripheral side yoke 34b are L1> L2. However, L1 = L2 or L1 <L2 may be satisfied.

The outer peripheral side yoke 34a has a circumferential middle portion recessed in the radial direction with respect to the yoke end portion connected to the side surface of the permanent magnet 32 on the outer peripheral surface on the armature 13 side (upper side in the drawing), and the concave portion 36 and the outer peripheral side yoke 34a. It has become. In this case, the outer peripheral side yoke 34a has a shape (boot shape) in which the peripheral intermediate portion is reduced in the radial direction and both end portions are enlarged between the permanent magnets 32 adjacent to each other in the circumferential direction.

Further, the inner peripheral side yoke 34b has a circumferential intermediate portion in the radial direction with respect to the yoke end portion connected to the side surface of the permanent magnet 32 on the inner peripheral surface on the opposite side (lower side in the drawing) of the armature 13. It is recessed and has a recess 37. In this case, the inner peripheral side yoke 34b has a shape (boot shape) in which the peripheral intermediate portion is reduced in the radial direction and both end portions are enlarged between the permanent magnets 32 adjacent to each other in the circumferential direction.

A yoke support portion 35 extending in the direction opposite to the armature 13 is connected between the permanent magnets 32 adjacent to each other in the circumferential direction to each inner peripheral side yoke 34b, and a yoke support portion 35 for each inner peripheral side yoke 34b is connected. Is integrally connected by a central fixing portion 33 as a connecting portion. Since the yoke support portion 35 is connected between the adjacent permanent magnets on each inner peripheral side yoke 34b, the inner (anti-armature side) radial end surface of the permanent magnets 32 is soft magnetic such as an electromagnetic steel plate. The body does not exist, and even if it exists, it covers the surface of the permanent magnet 32.

As shown in FIG. 1, the rotary electric machine system includes an inverter 41 and a control unit 42. The inverter 41 is connected to the armature winding 23 of each phase in the rotary electric machine 10, and adjusts the energizing current for each phase. As is well known, the inverter 41 is a bridge circuit having the same number of upper and lower arms as the number of phases of the phase winding, and each arm is provided with a switch (semiconductor switching element). The control unit 42 comprises a CPU and a microcomputer having various memories, and turns on and off each switch of the inverter 41 at a predetermined switching frequency (carrier frequency) based on, for example, a power running torque command value and a generated voltage command value. Feedback control is performed for each phase current of the rotary electric machine 10. Further, the control unit 42 can control the phase of the current (phase current) of each phase of the armature winding 23.

The characteristic action of the rotary electric machine 10 having the above configuration is as described with reference to FIG. 12, but the characteristic action of the rotary electric machine 10 will be described again with reference to FIG.

When a current is passed through the armature winding 23, a magnetomotive force is generated in a loop shape as shown by a broken line according to the energization phase of the armature winding 23. Here, in the permanent magnet 32, as shown in FIG. 4A, the direction of the magnetic flux of the magnet (the direction of N → S of the magnet) and the direction of the magnetomotive force of the armature winding 23 are the same. As shown in (b), the direction of the magnetic flux of the magnet and the direction of the magnetomotive force of the armature winding 23 may be opposite to each other. In the case of (a) has occurred magnetomotive force in the clockwise direction in the orientation of FIG, magnetic flux flows through the far side of the inner peripheral side yoke 34b relative to the armature 13. In the case of (b) is generated magnetomotive force in the counterclockwise direction in the orientation of FIG, magnetic flux flows through the outer peripheral side yoke 34a near side with respect to the armature 13. In the case of (a), the field magnetic flux is strengthened, and in the case of (b), the field magnetic flux is weakened. In such a case, the field magnetic flux can be changed according to the magnetomotive force of the armature winding, that is, the energization phase of the armature winding.

In the above configuration, the rotor yoke 34 is connected to the side surface of the permanent magnet 32, in other words, the rotor yoke 34 is in close contact with the permanent magnet 32 substantially perpendicular to the magnetization direction. Further, the rotor yoke 34 is connected to substantially the entire surface of the side surface of the magnet. Therefore, it is easy to change the flow of magnetic flux.

Further, FIGS. 5 and 6 are explanatory views of consideration using an equivalent circuit. FIG. 5 shows an equivalent circuit assuming the rotary electric machine 10 of the present embodiment, and FIG. 6 shows an equivalent circuit assuming a general surface magnet type motor having the same magnet arrangement and amount as the present embodiment. show. Rg corresponds to the air gap between the armature 13 and the rotor 12, Ry corresponds to the outer peripheral side yoke 34a and the inner peripheral side yoke 34b, respectively, and Rc corresponds to the rotor core C of a general surface magnet type motor. do. In FIGS. 5 and 6, FIG. 5B shows the time when the armature is energized, and FIG. 6C shows the time when the armature is not energized. The state of FIG. 5 (b) corresponds to the state of FIG. 4 (a).

In FIG. 5, it is considered that the magnet magnetic flux reaches the armature 13 with almost no leakage between the poles when the armature of (b) is energized. More specifically, even if a leakage occurs between the poles, a magnetic flux in the opposite direction exceeding that is supplied from the armature 13, the difference in subtraction becomes low, and eventually the outer peripheral side yoke 34a (armature side yoke) passes through. The amount of magnetic flux (amount of leakage flux) will be reduced.

Further, when the power is not supplied in (c), the rotor yokes 34 (34a, 34b) are in contact with the side surface of the permanent magnet 32, so that the magnetic flux is short-cut. In other words, it is considered that the magnetomotive force of the permanent magnet 32 is not fully used, resulting in self-circulation leakage.

In this case, the magnetic flux of the permanent magnet 32 is fully used when the armature is energized, whereas the magnetic flux is short-cut when the armature is not energized. Therefore, the rotary electric machine 10 having the above configuration has a configuration in which the working range of the permanent magnet 32 is relatively long in the magnetization direction when the armature is energized, and the working range of the permanent magnet 32 is relatively short in the magnetization direction when the armature is not energized. become. In this respect, the rotary electric machine 10 has an element that can be said to be a variable magnetic flux magnetic circuit.

As shown in FIG. 6, in a general surface magnet type motor, a permanent magnet 32 is coupled to a soft magnetic rotor core C on the side opposite to the armature (lower side in the figure), and the armature is energized. The magnetic flux path is the same at both the time and the non-energized state. Therefore, it is difficult to change the field magnetic flux.

Here, the advantage of providing the rotor yoke 34 separately on the inner peripheral side and the outer peripheral side will be supplemented with reference to FIG. 7. FIG. 7A shows a configuration in which the rotor yoke 34 is provided as a single layer without dividing the rotor yoke 34 into the inside and outside in the radial direction, and FIG. 7B shows a configuration in which the rotor yoke 34 is divided into the inside and outside in the radial direction and provided in two layers. ..

In the present embodiment, since the rotor yoke 34 is connected to the side surface of the permanent magnet 32, the magnetic flux circulates in the vicinity of the side surface of the magnet, and the magnetic flux constantly leaks. Here, in the case of FIG. 7A, since the magnetic flux constantly leaks from the side surface of the magnet, there is a concern that the efficiency may decrease. On the other hand, in the case of (b), by dividing the rotor yoke 34 in the radial direction, the magnetic flux circulation range is narrowed, so that magnetic flux leakage on the side surface of the magnet is reduced.

FIG. 8 shows the result of analyzing the flow of magnetic flux in the rotary electric machine 10 by FEA (finite element method) simulation. This shows the analysis result at the time of torque output. According to FIG. 8, it can be seen that the magnetic flux of the permanent magnet 32 effectively extends to the armature 13 rather than leaking back through the outer peripheral side yoke 34a. When a weakened field magnetic flux is generated, a large amount of magnetic flux leaks through the outer peripheral side yoke 34a.

Further, FIG. 9 compares the degree of weakening of the magnetic flux with respect to the armature current between the rotary electric machine 10 of the present embodiment and the general surface magnet type motor. It can be seen that the rotary electric machine 10 of the present embodiment can suppress the magnetic flux to the same level with a current about half that of a general surface magnet type motor. That is, it can be seen that the magnetic flux can be significantly changed by saving current.

Further, FIG. 10 shows the magnetic flux density distribution at the maximum torque and the minimum magnetic flux by the finite element method magnetic field analysis simulation. (A) shows the simulation result of the rotary electric machine 10 of the present embodiment at the maximum torque, (b) shows the simulation result of the rotary electric machine 10 of the present embodiment at the minimum magnetic flux, and (c) is the general. The simulation result at the maximum torque is shown for a typical surface magnet type motor, and (d) shows the simulation result at the minimum magnetic flux for a general surface magnet type motor.

In the rotary electric machine 10 of the present embodiment, the magnet magnetic flux reaches the armature 13 at full in the case of FIG. 10A, and the magnet magnetic flux is short-cut by the rotor yoke 34 in the case of (b) (self-circulation leakage occurs). It turns out that it is happening). Further, it can be seen that in the general surface magnet type motor, in the case of (d), the leakage flux to the armature side is larger than that of the rotary electric machine 10 shown in (b).

According to the present embodiment described in detail above, the following excellent effects can be obtained.

In the rotor 12 of the rotating electric machine 10, the plurality of permanent magnets 32 are separated from each other in the circumferential direction so that the magnetization direction is the radial direction and the poles facing the armature 13 are alternately N poles and S poles. The plurality of permanent magnets 32 are connected to each other by a rotor yoke 34, which is an iron core, and are connected in an annular shape. Here, the permanent magnet 32 has a configuration in which a field magnetic flux flows through the radial end surface on the armature 13 side and the circumferential side surface on the rotor yoke 34 side, and a magnetomotive force is generated by energization of the armature winding 23. In addition, the distribution of the field magnetic flux generated by the permanent magnet 32 differs depending on the direction of the magnetomotive force and the magnetic pole of each permanent magnet 32. In this case, the field magnetic flux flowing through the circumferential side surfaces of the adjacent permanent magnets 32 can be preferably changed. As a result, in the surface magnet type rotary electric machine 10, the field magnetic flux generated by the rotor 12 can be suitably changed to realize the variable field magnetic flux.

The rotor yoke 34 is provided in a plurality of radial directions between the permanent magnets 32 adjacent to each other in the circumferential direction. Here, in the configuration in which the rotor yoke 34 is connected to the side surface of the permanent magnet 32, the magnetic flux circulates in the vicinity of the side surface of the magnet, and the magnetic flux constantly leaks. However, by providing the rotor yoke 34 in a plurality of parts in the radial direction, magnetic flux leakage on the side surface of the magnet can be suppressed.

The rotor yoke 34 has a shape in which the middle portion in the circumferential direction is concave in the radial direction on the peripheral surface on the armature 13 side. Therefore, the flow of magnetic flux between the permanent magnets 32 arranged in the circumferential direction and the rotor yoke 34 can be promoted, and the leakage flux from the rotor yoke 34 to the armature 13 can be reduced. This makes it possible to improve energy efficiency.

A yoke support portion 35 extending in the direction opposite to the armature 13 is connected to the rotor yoke 34 between permanent magnets 32 adjacent to each other in the circumferential direction, and a plurality of yoke support portions 35 are integrated by a central fixing portion 33 (connecting portion). It was configured to be connected to. Thereby, in the configuration in which the rotor yokes 34 are provided between the permanent magnets 32 adjacent to each other in the circumferential direction, the plurality of permanent magnets 32 and the plurality of rotor yokes 34 can be suitably coupled while being arranged in an annular shape. In this case, since the yoke support portion 35 is connected to the opposite side of the armature 13 between the adjacent permanent magnets 32, magnetic flux leakage through the yoke support portion 35 can be suppressed.

The control unit 42 advances or delays the phase of the armature current in the rotational direction with respect to the q-axis of the rotor 12, thereby weakening or increasing the field magnetic flux. Thereby, the torque and the like can be controlled as desired.

(Other embodiments)
The above embodiment may be changed as follows, for example.

-In the above embodiment, the rotor yoke 34 is divided into two inside and outside in the radial direction, and each of them is the outer peripheral side yoke 34a and the inner peripheral side yoke 34b, but this configuration may be changed. The rotor yoke 34 may be divided into three or more in and out in the radial direction. Alternatively, the rotor yoke 34 may be provided without being divided in the radial direction.

-It is also possible to configure the rotor 12 as shown in FIG. In FIG. 11, a substantially disk-shaped insulating plate 51 fixed to the rotating shaft 11 is provided, and permanent magnets 32 are attached to the outer peripheral side of the insulating plate 51 at predetermined intervals, and between the permanent magnets 32. A rotor yoke 34 is attached to each. The insulating plate 51 is made of an insulating material such as synthetic resin. In this configuration, the insulating plate 51 is a holding member that holds the permanent magnet 32 and the rotor yoke 34.

-In the above embodiment, an example of application to an inner rotor type rotary electric machine has been described, but other than this, it can also be applied to an outer rotor type rotary electric machine.

10 ... Rotor, 12 ... Rotor, 13 ... Armature, 23 ... Armature winding, 32 ... Permanent magnet, 34 ... Rotor yoke (yoke member).

Claims (5)

Rotor (12) rotatably supported and
An armature (13) that is coaxially arranged with the rotor and is wound with an armature winding (23) that is energized with a multi-phase alternating current.
A surface magnet type rotary electric machine (10) equipped with
The rotor
A plurality of permanent magnets (32) provided at positions separated from each other in the circumferential direction so that the magnetization direction is the radial direction and the poles facing the armature are alternately N poles and S poles.
A yoke member (34) made of an iron core material, connecting the peripheral side surfaces of the permanent magnets between the permanent magnets adjacent to each other in the circumferential direction, and connecting the plurality of permanent magnets in an annular shape.
Have and
In the yoke member, it is possible to generate a field magnetic flux in the direction from one permanent magnet side to the other permanent magnet side between the peripheral side surfaces of the permanent magnets adjacent to each other in the circumferential direction.
The strength of the field magnetic flux from the permanent magnet to the armature is changed by generating field magnetic fluxes in the yoke members in opposite directions in the circumferential direction according to the energization phase of the armature winding. A rotating electric machine that makes it possible. The yoke members are provided between the peripheral side surfaces of the permanent magnets adjacent to each other in the circumferential direction as a plurality of yoke members (34a, 34b) extending in the circumferential direction from the circumferential side surfaces and arranging in the radial direction. The rotary electric machine according to claim 1. 2. The rotating electric machine described. A yoke support portion (35) extending in the direction opposite to the armature is connected to the yoke member between the permanent magnets adjacent to each other in the circumferential direction, and the yoke support portion for each yoke member is connected to the connecting portion. The rotary electric machine according to any one of claims 1 to 3, which is integrally connected by (33). The rotary electric machine according to any one of claims 1 to 4,
A control unit (42) that controls the phase of energization in the armature winding, and
It is a rotary electric system equipped with
The control unit weakens the field magnetic flux by advancing the phase of the armature current in the rotational direction with respect to the q-axis of the rotor, and causes the phase of the armature current to be in the rotational direction with respect to the q-axis of the rotor. A rotary armature system that controls to strengthen the field magnetic current by delaying it.

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