JP6074980B2 - Rotating machine - Google Patents

Description

  The present invention relates to a rotating machine that rotates a rotor with respect to a stator.

  Conventionally, a rotating machine including a stator and a rotor arranged with a magnetic gap (a narrow gap called an air gap, hereinafter referred to as a “magnetic gap”) between the stator and the stator. (For example, a PM motor) is known. A stator of a rotating machine is provided with a plurality of stator poles arranged at equal pitches in the circumferential direction, and windings (stator windings) are arranged in slots formed between adjacent stator poles. A magnetic field is generated in the stator by supplying electric power to the stator winding, and the rotor is rotated by the interaction between the magnetic field and the magnetic flux of the permanent magnet attached to the rotor (for example, Patent Documents). 1).

  By the way, recently, there are many rotating machines used in applications with large load fluctuations, such as automobile drive motors, and for these rotating machines, expansion of the output range and higher efficiency are required. Yes.

  In a conventional rotating machine with a permanent magnet attached to the rotor, the magnetic flux of the permanent magnet passes through the magnetic gap and is linked to the stator winding wound around the stator core and the stator pole, thereby generating an induced voltage. Here, the induced voltage determined by the magnetic flux amount and the rotational speed of the field, which is a magnetic field generated when rotating, increases in proportion to the rotational speed of the rotor. If a high induced voltage is set to ensure a large output (large torque) in the frequency range, it cannot be driven due to voltage limitations (exceeding the power supply voltage) in the high speed range, while it can be driven to the high speed range. If it is possible, the induced voltage becomes low in the low speed range, and the necessary high output (large torque) cannot be secured.

  Therefore, in the conventional permanent magnet synchronous rotating machine, when operating the rotor at a high speed by increasing the rotational speed of the rotor, the electrical design of the rotating machine (so as not to exceed the voltage limit) so that the induced voltage does not exceed the terminal voltage of the controller. In the high-speed range where the induced voltage is too high due to too much magnetic flux of the permanent magnets linked to the stator, the induced voltage is weakened by the stator power. It is configured to suppress.

  Thus, in the conventional rotating machine, the operation range is expanded by performing field-weakening control that actively weakens the magnetic flux of the permanent magnet.

JP2012-080715A

  However, if field-weakening control becomes excessive, the permanent magnet is irreversibly demagnetized beyond the nick point of the permanent magnet.

  Therefore, in a conventional rotating machine, the magnetic flux of the permanent magnet attached to the rotor is always in a state where it can act as a field magnetic flux interlinking with the stator iron core and the stator winding, so that the permanent magnet is not irreversibly demagnetized. Even if the magnetic flux density of the permanent magnet can be reduced to weaken the magnetic force, it is difficult to make the magnetic force zero, that is, the magnetic flux of the permanent magnet that can act as a field magnetic flux. And since the magnetic flux of the permanent magnet that can act as a field magnetic flux leaks from the rotor to the magnetic gap and always flows to the stator, there is a loss during rotation.

  Moreover, if it is an aspect which attaches a permanent magnet to a rotor, the situation where a permanent magnet will fly at the time of high-speed rotation of a rotor is assumed. In order to avoid such a situation, for example, a configuration in which a non-magnetic scattering prevention ring is attached so as to cover the surface of the permanent magnet closer to the stator pole is also conceivable, but in this case, the thickness of the scattering prevention ring is considered. The magnetic gap is enlarged by that amount, which can hinder high efficiency.

  Furthermore, in the process of assembling the motor with the rotor disposed inside the stator, the permanent magnets of the rotor are attracted to the stator poles, and the assembly work cannot be performed efficiently.

  The main cause of such a problem is that the magnetic flux of the permanent magnet cannot be adjusted in a rotating machine with a permanent magnet attached to the rotor.

  The main object of the present invention is to provide a rotating machine capable of adjusting the amount of magnetic flux of the field according to the fluctuation of the rotational speed and the operating state based on such examination results and realizing high efficiency. It is what.

  That is, the present invention relates to a rotating machine including a stator, a rotor that is arranged coaxially with the stator and forms a magnetic gap between the stator, and a shaft that rotatably supports the rotor with respect to the stator. is there. Here, the axis “coaxial with the stator” is a shaft. The number of “stator poles” is determined based on the number of poles, the number of phases, and the coefficient of the rotor.

The rotating machine according to the present invention includes, as a stator, a ring-shaped stator iron core, a single permanent magnet provided at a predetermined location of the stator iron core and having magnetism in the circumferential direction of the stator iron core, and a stator iron core. A single field winding wound around a position facing the permanent magnet and generating a magnetic flux in a direction opposite to the magnetic flux of the permanent magnet, and facing the rotor between the permanent magnet and the field winding of the stator core. And a plurality of 2n (n is a positive integer excluding zero) stator poles provided at equal pitches in the circumferential direction, and a stator winding wound around each stator pole, A rotor having a ring-shaped rotor core and a number of rotor poles protruding from the rotor core toward the stator and having a constant pitch in the circumferential direction and different from the stator poles is applied. Flux flow in non state magnetic flux of the permanent magnet passes through only the internal stator without passing through the magnetic gap of the stator poles and rotor poles, the field field winding generated by passing a predetermined direction of the current in the winding In addition, the magnetic gap and the magnetic flux passing through the rotor can be changed.

  The rotating machine according to the present invention is mainly an inner movable type in which the rotor is disposed on the inner peripheral side of the stator in the radial direction of the shaft that is the rotating shaft, but the rotor is disposed on the outer peripheral side of the stator in the radial direction of the rotating shaft. It does not actively exclude the outer movable type.

  In such a rotating machine according to the present invention, since the magnetism of a single permanent magnet arranged at a predetermined location of the stator iron core is provided in the circumferential direction of the stator core, the stator iron core is provided at a position facing the permanent magnet. If no current is flowing through the field winding (field winding non-excited state), the magnetic flux of the permanent magnet becomes a short-circuit magnetic flux that returns via the stator core. That is, when the magnetomotive force of the field winding is zero, the magnetic flux of the permanent magnet does not pass through the rotor due to the presence of the magnetic gap.

  On the other hand, when a current in a predetermined direction is passed through the field winding, the magnetic flux in the field winding is generated as a magnetic flux in the direction opposite to that of the permanent magnet. Therefore, the magnetic flux of the permanent magnet flowing in the stator core collides with the magnetic flux of the field winding in the stator core, and from the portion of the stator core where the permanent magnet is arranged to the portion of the stator core where the field winding is arranged. It passes through the magnetic pole with the rotor pole that can be opposed to this stator pole through the existing stator pole and reaches the rotor pole, the rotor core, another rotor pole, and the stator pole that can face this rotor pole. It flows through the magnetic gap, stator pole, and stator core in this order to reach the permanent magnet. Further, in a state where a current in a predetermined direction does not flow through the field winding (field winding non-excited state), the magnetic flux of the field winding is taken as the starting point of the stator core where the field winding is disposed. And flows through the stator iron core from this starting point, collides with the magnetic flux of the permanent magnet in the stator iron core, passes through the stator pole together with the magnetic flux of the permanent magnet, and passes through the magnetic gap between the rotor pole and the stator pole. The magnetic pole gap, rotor core, other rotor pole, magnetic gap with the stator pole that can face this rotor pole, stator pole, and stator core flow in this order to reach the above starting point.

  As described above, the rotating machine according to the present invention is in a state where the permanent magnetic flux does not flow or is difficult to flow in the rotor if a current in a predetermined direction does not flow through the field winding (field winding non-excited state). Can be secured. Therefore, in the rotating machine according to the present invention, an induced voltage is not generated in a state where a current in a predetermined direction does not flow through the field winding, and the cogging torque and the loss torque are zero or substantially zero, so that high efficiency can be achieved. it can. In a state where a current in a predetermined direction is passed through the field winding (field winding excitation state), the magnetic flux of the permanent magnet and the magnetic flux of the field winding are passed through the rotor (the magnetic flux of the permanent magnet is passed through the field winding). If a voltage is applied to the stator winding in this state, the magnetic flux of the permanent magnet and the magnetic flux of the field winding are interlinked with the stator winding. Acting as a magnetic flux, an induced voltage can be generated to rotate the rotor. Furthermore, in the rotating machine of the present invention, since the number of stator poles and rotor poles is different, sinusoidal excitation can be used, and a general-purpose inverter can be used. In the rotating machine of the present invention, since sinusoidal excitation can be used, it can be driven by a pulse power source used when the number of stator poles and rotor poles is the same.

  In the rotating machine of the present invention, the amount of magnetic flux passing through the rotor (the magnetic flux of the permanent magnet) is adjusted by adjusting the amount of current flowing through the field winding according to the required number of rotations (output) and torque. The amount of magnetic flux superposed on the magnetic flux of the field winding, and the amount of magnetic flux that is the sum of the magnetic flux of the permanent magnet and the magnetic flux of the field winding can be increased or decreased. The amount of magnetic flux can be increased or decreased. At this time, since the field weakening that weakens the field of the permanent magnet is unnecessary, the demagnetization phenomenon of the permanent magnet can be prevented, and for example, compared to the mode of performing the field weakening control and the field strengthening control selectively, Since the direction of current flowing through the field winding is only a fixed direction, it is not necessary to switch the direction of current flowing through the field winding.

  Moreover, since the rotating machine of the present invention is not configured to attach a permanent magnet to the rotor, it is possible to avoid a situation where the permanent magnets are scattered during high-speed rotation of the rotor. Furthermore, if the rotating machine has a permanent magnet attached to the rotor, the anti-scattering member provided to prevent the permanent magnet from scattering is not necessary in the rotating machine of the present invention. It is possible to avoid the enlargement of the magnetic gap by attaching the anti-scattering member to the surface of the permanent magnet that faces the stator, which contributes to higher efficiency.

  In particular, the rotating machine of the present invention is advantageous in that the rotor can be formed only from a magnetic material.

  In addition, in the rotating machine of the present invention, the magnetic flux of the permanent magnet stays in the stator without current flowing through the field windings attached to the stator. In the process of inserting the unit in which the rotor and the shaft are assembled, by preventing current from flowing through the field winding, it is possible to prevent the permanent magnet from being attracted to the rotor unexpectedly, and to perform the insertion work smoothly and appropriately. It can be carried out.

  In the present invention, it is also possible to configure a rotating machine in which a plurality of sets of stators and rotors are arranged in the axial direction of the shaft, and the phases of the sets are shifted in the circumferential direction of the shaft. In this case, for example, if the number of groups is “n”, the groups may be shifted in the circumferential direction of the shaft by “360 ÷ n” degrees. The number n of stator / rotor pairs means the number n of phases of the rotating machine. For example, if there are three pairs, the rotating machine has a three-phase structure, and “360 ÷ 3”, that is, 120 degrees in the circumferential direction of the shaft. As a result, the torque due to all phase currents becomes positive, the combined torque is large, and the torque pulsation is small. If the three sets of stators and the shaft are not shifted in the circumferential direction, the torque due to a certain one-phase current becomes positive, but the torque becomes negative due to the remaining two-phase current, resulting in torque pulsation.

  According to the present invention, one permanent magnet and one field winding are arranged at opposing positions in the stator core so that they do not leak into the magnetic gap or are difficult to leak in the non-excited state of the field winding. The magnetic flux of the magnetic short-circuited permanent magnet is made to flow into the magnetic gap and the rotor together with the magnetic flux of the field winding by passing a current through the field winding so that it can be changed to a magnetic flux that can act as a field magnetic flux. Therefore, the amount of magnetic flux of the field can be adjusted according to the fluctuation of the rotation speed and the operating condition, and a rotating machine that operates with high efficiency in any rotation range corresponding to a wide range of operation can be provided. .

The cross-sectional schematic diagram of the rotary machine which concerns on one Embodiment of this invention. The figure which shows typically the flow of the magnet magnetic flux in a field winding non-excitation state corresponding to FIG. The figure which shows typically the flow of the magnet magnetic flux in a field winding excitation state corresponding to FIG. The figure which shows the modification of the rotary machine which concerns on the same embodiment. The figure which shows arrangement | positioning of a stator among the rotary machines of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The rotating machine X according to the present embodiment can be applied as a drive motor of an electric vehicle (EV) or a hybrid vehicle (HEV) (not shown), for example.

  As shown in FIG. 1, the rotating machine X includes a stator 1, a rotor 2 that is arranged coaxially with the stator 1 and that forms a magnetic gap with the stator 1, and the rotor 2 can rotate with respect to the stator 1. And a rotor support member 3 to be supported. The rotating machine X according to the present embodiment is an inner movable rotating machine X in which the rotor 2 is disposed radially inward of the rotating shaft W with respect to the stator 1.

  In the present embodiment, the shaft 3 that functions as the rotation axis W itself of the rotor 2 is applied as the rotor support member. That is, the shaft 3 and the rotor 2 are configured to be integrally rotatable.

  The stator 1 includes a stator core 11 (corresponding to the stator iron core of the present invention) and a plurality of stator teeth 12 protruding from the stator core 11 toward the rotor 2 and arranged at an equiangular pitch in the circumferential direction A (the stator pole of the present invention). ), A stator winding 13 wound around each stator tooth 12, and a single coil disposed at a predetermined location (in the illustrated example, the central portion of one side of the stator core 11 having a rectangular tube shape). Permanent magnet 14 and a single field winding 15 wound around the stator core 11 at a position facing the permanent magnet 14.

  The stator core 11 is a magnetic body whose cross-sectional shape perpendicular to the axial direction of the shaft 3 forms a ring shape. In the present embodiment, the stator core 11 in which unit stator cores 11a divided into four in the circumferential direction A are integrally joined by an appropriate means is applied. However, a stator core that is not divided in the circumferential direction A may of course be used. . A part of the stator core 11 is formed with a hollow portion 11s in which the permanent magnet 14 is disposed. As shown in FIG. 1, the hollow portion 11 s may penetrate the stator core 11 in the thickness direction (diameter direction of the shaft 3), or the stator core 11 is recessed by a predetermined region in the thickness direction. (Not shown) may be used. Further, in the present embodiment, the stator core 11 is used in which the cross-sectional shape orthogonal to the axial direction of the shaft 3 forms a substantially rectangular tube shape (the corners are partially cylindrical), but a polygonal tube shape other than the square tube shape or A cylindrical stator core 11 may be used. The stator core 11 of this embodiment forms a through-hole penetrating in the axial direction of the shaft 3 at the corner, and the stator 1 can be fixed to an attachment object through the through-hole.

  The stator teeth 12 protrude from the inward surface of the stator core 11 toward the rotor 2 side (the radially inner side of the shaft 3). The rotating machine X of the present embodiment has a total of four stator teeth 12 protruding from each corner of the stator core 11 toward the rotor 2, and a stator winding 13 is wound around each stator tooth 12.

  In the rotating machine X of the present embodiment, the permanent magnet 14 is disposed in the hollow portion 11 s of the stator core 11. In the present embodiment, a permanent magnet 14 is used in which the dimension along the radial direction of the shaft 3 is set to be the same as or substantially the same as the thickness of the stator core 11. The permanent magnet 14 is magnetized in the circumferential direction A of the stator core 11. In FIG. 1, a configuration in which a permanent magnet 14 is arranged in a part of the stator core 11 in which the surface on the left side in the circumferential direction A of the stator core 11 in FIG. Illustrated. The permanent magnet 14 of the present embodiment is disposed on a part of the stator core 11 in a state where the S pole and the N pole are in close contact with the end face of the stator core 11 (opening edge of the cavity portion 11s) without any gap.

  The field winding 15 is wound around the stator core 11 at a position facing the permanent magnet 14. When a direct current is passed through the field winding 15, a magnetic flux in the direction opposite to the magnetic flux of the permanent magnet 14 is generated.

  In the present embodiment, the permanent magnet 14 is arranged on one side (upper side in FIG. 1) of two opposing sides of the stator core 11 having a rectangular tube shape, and the other side (lower side in FIG. 1). ) Is wound with the field winding 15. Therefore, the rotating machine X according to the present embodiment in which the stator teeth 12 are provided at each corner of the stator core 11 is arranged between the portion where the permanent magnet 14 is disposed and the portion where the field winding 15 is wound in the stator core 11. It has 2n (n is a positive integer excluding zero, and is 1 in this embodiment) stator teeth 12 at an equal pitch in the direction A.

  As shown in FIG. 1, the rotor 2 includes a ring-shaped rotor core 21 (corresponding to the rotor core of the present invention), and a rotor tooth 22 (projecting from the rotor core 21 toward the stator 1 side (the radially outer side of the shaft 3)). Equivalent to the rotor pole of the present invention). In the rotor 2 of the present embodiment, the rotor core 21 and the rotor teeth 22 are integrally formed. In this embodiment, the rotor core 21 in which the unit rotor core 21 divided into six in the circumferential direction A is integrally joined by an appropriate means is applied. However, a rotor core that is not divided in the circumferential direction A may be used. . Further, a shaft insertion hole 21 s through which the shaft 3 can be inserted is formed at the center of the rotor core 21. The shaft 3 inserted through the shaft insertion hole 21 s can rotate integrally with the rotor 2.

  The rotating machine X of the present embodiment shown in FIG. 1 has six rotor teeth 22 projecting radially from the outward surface (outer peripheral surface) of a cylindrical rotor core 21. Here, in the rotating machine X of the present embodiment, the stator teeth 12 provided at an equal pitch on the inward surface of the ring-shaped stator core 11, and the rotor provided at an equal pitch on the outer surface of the ring-shaped rotor core 21. The number of teeth 22 is different from each other. In the present embodiment, the number of stator teeth 12 is set to 4, and the number of rotor teeth 22 is set to 6.

  The rotating machine X according to the present embodiment forms a magnetic gap that circulates in the circumferential direction A of the rotating shaft W between the stator 1 and the rotor 2, more specifically between the stator teeth 12 and the rotor teeth 22. ing. In the present embodiment, the inwardly facing surface (projecting end surface) of each stator tooth 12 is set to a partial arc surface that coincides on the same arc centered on the axial center of the shaft 3, and the outward surface ( The projecting end surface is set to a partial arc surface that is concentric with the inward surface of each stator tooth 12 and coincides with an arc whose diameter is set slightly smaller than the inward surface of each stator tooth 12.

  Here, in the rotating machine X of the present embodiment, a plurality of rotors 2 are arranged in the axial direction A of the shaft 3 (hereinafter sometimes simply referred to as “axial direction A”), and each rotor 2 has a stator. 1 are associated with each other. The sets of the stator 1 and the rotor 2 are arranged in the axial direction of the shaft 3, and the phase of each set is set to a predetermined angle with respect to the circumferential direction A of the shaft 3, specifically, the number of sets is “n”. In this case, they are arranged in a state of being shifted in the circumferential direction of the shaft 3 by an angle of “360 ÷ n”. Just shift it. Here, the set number n means the number of phases of the rotating machine X. For example, the rotating machine X having three sets of the stator 1 and the rotor 2 is a three-phase rotating machine X, and the set of the stator 1 and the rotor 2 Are arranged in a state shifted by 120 degrees in the circumferential direction of the shaft 3.

  Next, the operation and action of the rotating machine X according to this embodiment having such a configuration will be described.

  In the rotating machine X of the present embodiment, when no direct current is flowing in the field winding 15 provided in the stator core 11 (field winding is not excited), the magnetic flux of the permanent magnet 14 (hereinafter referred to as “magnet flux”). FIG. 2 (the figure schematically shows the magnetic flux of the permanent magnet 14 in the field winding non-excited state). Compared to FIG. 1, each of the stator 1 and the rotor 2 is shown in FIG. Although some distortion appears in the outer edge shape of the portion, the distortion has no essential meaning, and the distortion of the magnetic flux itself of the permanent magnet 14 has no essential meaning, as shown in FIG. 14, when the surface magnetized to the N pole (N pole magnetized surface) is taken as the starting point, the N pole magnetized surface of the permanent magnet 14, the other magnetized surface of the permanent magnet 14 flowing through the stator core 11. That is, the magnetic flux path of the permanent magnet 14 (magnetism) ) Is inevitably selected as the magnetic path having the smallest overall magnetic resistance, so that the magnetic flux in the field winding non-excited state flows while avoiding the magnetic gap between the rotor 2 and the stator 1. Accordingly, in the field winding non-excited state, the magnetic flux of the permanent magnet 14 becomes a short-circuit magnetic flux that returns via the stator core 11. Hereinafter, the magnetic flux of the permanent magnet 14 in the field winding non-excited state is referred to as “non-excited state magnet”. In this way, the non-excited state magnet magnetic flux is confined in the stator 1 and does not flow into the rotor 2. Therefore, no induced voltage is generated, and it can be said that the permanent magnet 14 is in a safe state. The amount of magnetic flux is always constant.

  On the other hand, in the rotating machine X of the present embodiment, when a direct current in a predetermined direction is passed through the field winding 15 (field winding excitation state), specifically, as shown in FIG. When a direct current in a direction opposite to the direction of the magnet magnetic flux is passed through the field winding 15, the magnet magnetic flux collides with the magnetic flux of the field winding 15 in the stator core 11, and the magnetic flux of the field winding 15 resists. And passes through the magnetic gap between the rotor 2 and the stator 1, which has a smaller resistance than the magnetic flux of the field winding 15, and the rotor teeth 22, the rotor core 21, the other rotor teeth 22, and the magnetism between the rotor teeth 22 and the stator teeth 12. The magnetic flux returns to the permanent magnet 14 through the gap, the stator teeth 12 and the stator core 11. As the direct current flowing through the field winding 15 is increased, the amount of magnetic flux in the field winding 15 can be increased, and the region where the field winding 15 is disposed in the stator core 11 and the vicinity thereof. Becomes close to magnetic saturation, and it becomes difficult for the magnetic flux to flow in these regions, and the amount of the magnetic flux flowing in the magnetic gap and the rotor 2 increases accordingly.

  The rotating machine X according to the present embodiment causes the field winding 15 of the stator core 11 to be turned on when a current (large current) of a predetermined value or more is passed through the field winding 15 (field winding excitation state). As shown in FIG. 3, the magnetic flux does not flow in these regions and all or almost all of the magnetic flux leaks to the magnetic gap, and the magnetic flux that flows in the rotor 2 becomes magnetic saturation. The amount of increases. The magnetic flux of the field winding 15 is also the same as that of the rotor core 21, the rotor teeth 22, the magnetic gap, the rotor teeth 22, the rotor core 21, the other rotor teeth 22, the magnetic gap between the rotor teeth 22 and the stator teeth 12, the stator teeth 12, The stator core 11 flows in this order. Therefore, as the amount of current flowing through the field winding 15 increases, the total amount of magnetic flux passing through the rotor 2 (the sum of the magnet magnetic flux and the magnetic flux of the field winding 15) also increases.

  In the rotating machine X according to the present embodiment, an induced voltage is generated when a magnetic flux flows to the rotor 2 together with the magnetic flux of the field winding 15 and further current flows to the stator winding 13. 2 can be rotated, and the amount of magnetic flux (permanent magnet) flowing through the rotor 2 can be adjusted by adjusting the amount of current (field power) flowing through the field winding 15 according to the required number of rotations (output) and torque. 14) and the magnetic flux of the field winding 15 can be increased or decreased.

  When such a rotating machine X is applied as a drive motor for an electric vehicle or a hybrid vehicle, the coil (stator winding 13) of the stator 1 is energized and the field winding 15 is predetermined in a low speed range including the start time. The excited rotor 2 is rotationally driven by flowing a direct current in the direction to switch from the field winding non-excitation state to the field winding excitation state.

  The rotating machine X according to the present embodiment increases the amount of current flowing through the field winding 15 (increases the field power) in a low speed range where a large torque is required, thereby increasing the magnitude according to the field power. The magnetic flux of the field winding 15 and the magnetic flux of the permanent magnet 14 induced by the magnetic flux of the field winding 15 can pass through the rotor 2, and the field that flows through the rotor 2 and interlinks with the stator winding 13. The amount of magnetic flux can be increased (the magnetic flux density can be increased). Therefore, for example, even when the current flowing through the stator winding 13 is not increased, a large torque can be obtained by performing field control for flowing a current in a predetermined direction through the field winding 15, and when field control is not performed. Compared to the induced voltage, the induced voltage can be increased.

  Further, the rotating machine X of the present embodiment operates in the field winding excitation state in the medium speed range, and maintains the induced voltage constant by reducing the field power as compared with the low speed range, and requires torque. The magnetic flux density in the rotor 2 is suppressed by reducing the magnetic flux that passes through the rotor 2 and interlinks with the stator winding 13 from the low-speed region by further reducing the field power when reaching the region that is not. Can do. And in the rotary machine X of this embodiment, iron loss can be reduced by suppressing the magnetic flux density of the rotor 2.

  Further, the rotating machine X according to the present embodiment can be rotated only by the reluctance torque by bringing the field power close to zero in the high speed range. That is, by bringing the field power close to zero, the amount of magnetic flux of the field winding 15 approaches zero, and the amount of magnetic flux that passes through the rotor 2 and interlinks with the stator winding 13 is reduced from the middle speed range. The magnetic flux density in the rotor 2 can be further suppressed. Further, by bringing the field power close to zero, the copper loss of the field winding 15 is reduced as compared with the low speed region and the medium speed region, and the iron loss can be reduced along with the reduction of the magnetic flux density in the high speed region. In the rotating machine X according to the present embodiment, since the induced voltage is low (magnetic flux density is low) in the high-speed rotation region, iron loss can be reduced.

  The rotating machine X of the present embodiment having such a configuration is configured such that the magnetic flux of the permanent magnet 14 does not pass through the rotor 2 or hardly passes through the rotor 2 in the field winding non-excited state. Thus, the magnetic flux interlinking with the stator winding 13 can be made zero or substantially zero, and the cogging torque can be made zero or substantially zero. In addition, in this field winding non-excitation state, no induced voltage is generated and a safe state can be ensured, and when the control device (power supply, inverter, etc.) is stopped, a state in which no induced voltage is naturally generated is ensured. It helps to prevent damage to the control equipment. Further, in the rotating machine X of the present embodiment, when a current in one direction flows through the field winding 15, the magnetic flux of the permanent magnet 14 along with the magnetic flux of the field winding 15 passes through the rotor 2 and is stator. The windings 13 are linked to each other, an induced voltage can be generated to rotate the rotor 2, and the amount of current flowing through the field winding 15 is adjusted according to the required number of rotations (output) and torque. Thus, the amount of magnetic flux interlinked with the stator winding 13 via the rotor 2 can be increased or decreased. At this time, since the field weakening that weakens the field of the permanent magnet 14 is unnecessary, the demagnetization phenomenon of the permanent magnet 14 constituting the permanent magnet 14 can be prevented. The rotating machine X according to the present embodiment can prevent / suppress the occurrence of field copper loss that may occur when the field weakening control is executed. Compared with a mode in which the field weakening control and the field strengthening control are selected and performed, Since the direction of the current flowing through the magnetic winding 15 is only a fixed direction, there is no need to switch the direction of the current flowing through the field winding 15, and a “stator that does not contribute to torque” is required for field weakening control at high speeds. "Electric power" becomes unnecessary, and the stator copper loss can be reduced.

  Thus, in the rotating machine X of the present embodiment, when the magnetomotive force of the field winding 15 is zero, the magnetic flux of the permanent magnet 14 that does not pass through the rotor 2 flows through the field winding 15. Thus, it is possible to superimpose it on the magnetic flux of the field winding 15 and change it to a magnetic flux (field magnetic flux) that passes through the rotor 2 and is linked to the stator winding 13. While avoiding, high efficiency can be realized in any rotation region corresponding to a wide range of operation from low speed / high torque state to high speed / low torque state.

  Moreover, since the rotating machine X of this embodiment is not the structure which attaches the permanent magnet 14 to the rotor 2, the situation where the permanent magnet 14 scatters during the high speed rotation of the rotor 2 can be avoided. Furthermore, if the rotating machine X of the present embodiment has a configuration in which the permanent magnet 14 is attached to the rotor 2, a scattering prevention member provided to prevent the permanent magnet 14 from scattering is unnecessary. Reduction of the number of points and prevention of expansion of the magnetic gap due to the presence of the scattering prevention member can be realized.

  In particular, the rotating machine X of the present embodiment is advantageous in that the rotor 2 can be formed only from a magnetic material.

  In addition, in the rotating machine X of the present embodiment, the magnetic flux of the permanent magnet 14 stays in the stator 1 in a state where no current is passed through the field winding 15 attached to the stator 1. Among them, in the step of inserting the unit in which the rotor 2 and the shaft 3 are assembled into the internal space of the stator 1, the situation that the permanent magnet 14 is unexpectedly attracted to the rotor 2 by not passing current through the field winding 15. Therefore, the insertion operation can be performed smoothly and appropriately.

  Further, in the rotating machine X of the present embodiment, since the numbers of the stator poles 12 and the rotor poles 22 are different, sinusoidal excitation can be used, and a general-purpose inverter can be used. Further, in the rotating machine X of the present embodiment, since sinusoidal excitation can be used, it can be driven by a pulse power source used when the number of stator poles 12 and rotor poles 22 is the same. Rich in versatility.

  Further, the rotating machine X of the present embodiment includes a plurality of sets of the stator 1 and the rotor 2, and the phases of the groups arranged in the axial direction of the shaft 3 are set to a predetermined angle in the circumferential direction of the shaft 3, specifically, A value obtained by dividing one rotation of 360 degrees by the number n of sets of the stator 1 and the rotor 2. If there are three sets, they are shifted by 120 degrees in the circumferential direction of the shaft 3. Thus, the combined torque is large and the torque pulsation is small.

  In addition, this invention is not limited to embodiment mentioned above. For example, the rotating machine of each embodiment described above is used for applications other than vehicle drive motors such as electric vehicles and hybrid vehicles, for example, or a test apparatus for performing a load test on a motor mounted on a hybrid vehicle or electric vehicle. Speed and output of load devices, VSCF (variable speed constant frequency power supply device for short), wind power generators, large generators, starter generators (aircraft), or electric motors for construction machinery It can be used as various load devices, generators and electric motors that vary greatly.

  Further, the stator core and the rotor core may be a laminated body formed by laminating magnetic plate-like members, or may be a lump that is one block as a whole. The number of stator teeth and rotor teeth and the pitch between teeth adjacent in the circumferential direction of the rotating shaft can be appropriately changed.

  The outer edge shape (the shape of the radially outward surface) and the inner edge shape (the shape of the radially inward surface) of the stator core are not limited to the shapes shown in the above-described embodiments, and may be a circle or a polygon other than a rectangle. Alternatively, the shape of the radially outward surface and the shape of the radially inward surface may be different from each other. FIG. 4 shows a rotating machine X that employs a stator core 11 in which the radially outward surface has a circular shape and the radially inward surface has a substantially octagonal shape. The rotating machine X shown in FIG. 4 has a configuration similar to that of the rotating machine X shown in FIG. 1, and parts / parts corresponding to the parts and parts in FIG. Yes. Further, the rotating machine X shown in FIG. 4 is a three-phase type including three sets of the stator 1 and the rotor 2, and can be grasped from FIG. 5 showing the intervals between the stators 1 in FIG. 4 and FIG. In order to make it possible, the phases of the three sets of the stator 1 and the rotor 2 arranged side by side in the axial direction of the shaft 3 are arranged in a state where they are shifted by 120 degrees in the circumferential direction of the shaft 3. Specifically, based on FIG. 5, among the three stators 1 arranged in the axial direction of the shaft 3, the center of the permanent magnet 14 of the middle stator 1 is used as a reference (reference point), and the lower left (front) of the figure. The center of the permanent magnet 14 of the stator 1 is shifted by minus 120 degrees in the circumferential direction of the shaft 3 with respect to the reference point. They are arranged in a state shifted by 120 degrees in the direction. Thereby, the current phase of the field winding 15 attached to each stator 1 becomes a phase shift of 120 degrees. As a result, the torque due to all phase currents is in the positive direction, the combined torque is large, and the torque pulsation is small. In particular, each of the plurality of sets of stators 1 and rotors 2 arranged side by side in the axial direction of the shaft 3 has a permanent magnet 14 and a field winding 15 to shift the phases of the sets of the stator 1 and the rotor 2 in the circumferential direction of the shaft 3 by a predetermined angle. By shifting the position of the stator 1 by a predetermined angle in the circumferential direction of the shaft 3, it is possible to avoid a situation in which the field windings 15 wound around the respective stators 1 interfere with each other in the axial direction of the shaft 3. .

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Stator 11 ... Stator iron core (stator core)
12: Stator pole (stator teeth)
13 ... Stator winding 14 ... Permanent magnet 15 ... Field winding 2 ... Rotor 21 ... Rotor core (rotor core)
22 ... Rotor pole
3 ... Rotor support member (shaft)
X ... Rotating machine

Claims (2)

A rotating machine comprising: a stator; a rotor disposed coaxially with the stator and forming a magnetic gap with the stator; and a shaft that rotatably supports the rotor with respect to the stator;
The stator is
A ring-shaped stator iron core, a single permanent magnet provided at a predetermined position of the stator iron core and having magnetism in the circumferential direction, wound around a position facing the permanent magnet in the stator iron core, and A single field winding that generates a magnetic flux in a direction opposite to the magnetic flux of the permanent magnet, and projects out toward the rotor between the permanent magnet and the field winding in the stator core and has an equal pitch in the circumferential direction 2n (where n is a positive integer excluding zero) provided with a plurality of stator poles, and stator windings wound around each of these stator poles,
The rotor is
A ring-shaped rotor core, and a number of rotor poles that protrude from the rotor core toward the stator and have a different number from the stator poles at an equal pitch in the circumferential direction;
The magnetic flux of the permanent magnet that passes through the stator without passing through the magnetic gap between the stator pole and the rotor pole in a predetermined direction to the field winding in a state where no current is passed through the field winding. The rotating machine is characterized in that it can be changed to a magnetic flux passing through the magnetic gap and the rotor together with the magnetic flux of the field winding generated by flowing the current. The rotating machine according to claim 1, wherein a plurality of sets of the stator and the rotor are arranged in the axial direction of the shaft, and the phases of the sets are shifted in the circumferential direction of the shaft.

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