JP6645351B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electric machine.

  As a rotating electric machine that outputs torque by using a magnetic flux of a permanent magnet, a rotating electric machine that can vary an effective magnetic flux amount by a permanent magnet is known. For example, Patent Literature 1 discloses a rotating electric machine having a stator on which an armature winding is wound and a rotor rotatably provided through a gap between the stator and the stator. A structure is described in which the rotor is divided into two parts, a first rotor and a second rotor, and field magnets having different polarities are alternately arranged in the rotation direction.

  With such a structure, the rotating electric machine described in Patent Literature 1 operates the second rotor in accordance with a change in the torque or the number of revolutions, and determines the polarity of the permanent magnet of the first rotor and the permanent magnet of the second rotor. By changing the positional relationship with the polarity, the effective magnetic flux amount of the permanent magnet can be adjusted. At this time, the rotating electric machine described in Patent Document 1 changes the positional relationship between the polarity of the permanent magnet of the first rotor and the polarity of the permanent magnet of the second rotor by using a control signal input to the actuator. Control is performed so that the two rotors are positioned in a predetermined state.

JP 2010-246196 A

  However, the rotating electric machine described in Patent Literature 1 requires an actuator and a control device for controlling the actuator in order to position the second rotor in a predetermined state, as described above. Further, precise control is required because the second rotor is mechanically moved so that the first rotor and the second rotor have a predetermined positional relationship. Therefore, the magnetic flux of the permanent magnet cannot be varied with a low-cost configuration.

  The present invention has been made in view of the above circumstances, and has as its object to provide a rotating electric machine that can vary the magnetic flux of a permanent magnet with a low-cost configuration.

  In order to achieve the above object, the present invention is a rotating electric machine including a stator having an armature coil and a rotor having a permanent magnet, wherein the stator has a plurality of the armature coils wound in a concentrated manner. The stator has a stator tooth, the rotor includes a plurality of rotor teeth including the permanent magnet, and an induction coil wound around the rotor tooth on the stator side of the permanent magnet. A magnetic path member is disposed between the adjacent rotor teeth via a gap, and the permanent magnets adjacent to each other in the circumferential direction are provided on the magnetic path member based on an induction current generated by the induction coil. A variable field coil capable of adjusting the amount of magnetic flux that is short-circuited between the permanent magnet and the rotor tooth is provided with a gap extending in the axial direction on the radially outer side of the permanent magnet. And wherein the are.

  According to the present invention, it is possible to provide a rotating electric machine capable of changing the magnetic flux of a permanent magnet with a low-cost configuration.

FIG. 1 is a cross-sectional view of a rotating electric machine according to an embodiment of the present invention, cut along a plane orthogonal to a rotation axis. FIG. 2 is a diagram showing a magnetic flux density and a magnetic flux line of a second spatial harmonic generated in the rotating electric machine according to one embodiment of the present invention. FIG. 3 is a schematic diagram showing connection between an induction coil, a variable field coil, and a diode in the rotary electric machine according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a magnetic flux path when the rotor of the rotary electric machine according to one embodiment of the present invention is rotating at a low speed. FIG. 5 is a diagram showing a magnetic flux density and a magnetic flux line when the rotor of the rotary electric machine according to one embodiment of the present invention is rotating at a low speed. FIG. 6 is a schematic diagram illustrating a magnetic flux path when the rotor of the rotary electric machine according to one embodiment of the present invention is rotating at a high speed. FIG. 7 is a diagram illustrating a magnetic flux density and a magnetic flux line when the rotor of the rotary electric machine according to one embodiment of the present invention is rotating at a high speed. FIG. 8 is a cross-sectional view showing a magnetic flux that is short-circuited between stator teeth. FIG. 9 is a sectional view showing a modification of the rotating electric machine according to one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 8 are diagrams illustrating a rotating electric machine according to one embodiment of the present invention.

  As shown in FIG. 1, a rotating electric machine 1 includes a stator 10 having three-phase armature coils 11 of W-phase, V-phase, and U-phase that generate a magnetic flux when energized, and rotates by passing a magnetic flux generated by the stator 10. Rotor 20 and a magnetic path member 30.

(Stator)
Stator 10 is fixed to a motor case (not shown). The stator 10 includes an annular stator core 12 made of a magnetic material having a high magnetic permeability. A plurality of stator teeth 13 protruding radially inward are formed on the stator core 12 along the circumferential direction.

  Slots 14 that are groove-shaped spaces are formed between the stator teeth 13 that are adjacent in the circumferential direction. The radial direction indicates a direction orthogonal to the direction in which the rotation axis of the rotor 20 extends. The inner side in the radial direction indicates a side closer to the rotation axis of the rotor 20 in the radial direction. The outer side in the radial direction indicates a side farther from the rotation axis of the rotor 20 in the radial direction. The circumferential direction indicates a circumferential direction around the rotation axis of the rotor 20. Note that the radial direction is shown in a radial direction about the rotation axis.

  In each slot 14 of the stator core 12, three-phase armature coils 11 of W-phase, V-phase, and U-phase are arranged along the circumferential direction of the stator core 12. The W-phase, V-phase and U-phase armature coils 11 are wound around the stator teeth 13 by concentrated winding.

  Thus, the stator 10 has the plurality of stator teeth 13 around which the armature coils 11 are concentratedly wound. The stator 10 generates a rotating magnetic field that rotates in the circumferential direction when the three-phase alternating current is supplied to the armature coil 11. The magnetic flux generated in the stator 10 (hereinafter, this magnetic flux is referred to as “main magnetic flux”) is linked to the rotor 20. Thereby, the stator 10 can rotate the rotor 20.

  As described above, the stator 10 has the armature coil 11 wound around the stator teeth 13 in a concentrated manner. For this reason, when a three-phase alternating current is supplied to the armature coil 11, in addition to a rotating magnetic field that rotates in synchronization with the rotation of the rotor 20, a harmonic rotating magnetic field that is asynchronous with the rotation of the rotor 20 is generated in the stator 10. I do. The harmonic rotating magnetic field includes a second spatial harmonic in the stationary coordinate system (a third time harmonic in the synchronous rotating coordinate system). Therefore, a harmonic component is superimposed on the magnetic flux generated in the stator 10.

(Rotor)
The rotor 20 is disposed radially inward of the stator core 12 such that the outer peripheral surface faces the inner peripheral surface of the stator core 12. The rotor 20 includes an annular rotor core 21 and an induction coil 22.

  The rotor core 21 is made of a magnetic material having a high magnetic permeability, and is fixed so as to be able to rotate integrally with the rotation axis of the rotor 20. A plurality of rotor teeth 23 projecting radially outward from the rotor core 21 are formed on the rotor core 21 at predetermined intervals along the circumferential direction of the rotor core 21. The rotation axis of the rotor 20 is fixed to the inner peripheral surface of the rotor core 21 and extends in a direction orthogonal to the radial direction of the rotor core 21. In the following, the direction in which the rotation axis of the rotor 20 extends is referred to as the axial direction.

  The rotor teeth 23 include a permanent magnet 24. The permanent magnet 24 is formed of, for example, a neodymium magnet (Nd-Fe-B magnet), and is included in the rotor teeth 23. The permanent magnet 24 is arranged on the rotor teeth 23 such that the direction of the magnetic flux is radial. The permanent magnets 24 are arranged so that the polarities of the rotor teeth 23 adjacent in the circumferential direction are opposite to each other. As the permanent magnet 24, a set of a pair of permanent magnets which are arranged in a V-shape in each rotor tooth 23 may be used.

  The induction coil 22 is wound around each rotor tooth 23 on the stator 10 side with respect to the permanent magnet 24. The induction coil 22 is wound so as to surround the side surface of the tip 23 a of the rotor tooth 23.

  The induction coil 22 generates an induction current based on a harmonic component superimposed on a magnetic flux generated on the stator 10 side. Specifically, when the three-phase alternating current is supplied to the armature coil 11 and a rotating magnetic field is generated in the stator 10, the magnetic flux of the harmonic component generated on the stator 10 is linked to the induction coil 22. Thereby, the induction coil 22 induces an induced current.

  FIG. 2 shows the magnetic flux density and magnetic flux lines of the second spatial harmonic generated on the stator 10 side. FIG. 2 shows that the smaller the distance between the magnetic flux lines, the higher the magnetic flux density.

  As shown in FIG. 2, most of the magnetic flux of the second spatial harmonic generated on the side of the stator 10 is linked to the tip 23 a of the rotor tooth 23. Accordingly, more magnetic flux of the second spatial harmonic is linked to the induction coil 22 wound so as to surround the side surface of the tip 23a of the rotor tooth 23.

  In the rotor teeth 23, a gap 25 extending in the axial direction is formed radially outward of the permanent magnet 24. Specifically, the grooves of the rotor teeth 23 are cut out from the outer peripheral surface 23c on the outer side in the radial direction to the outer peripheral surface on the outer side in the radial direction of the permanent magnet 24. The groove is formed so as to penetrate the rotor teeth 23 in the axial direction. The air gap 25 is a space defined by a surface facing the circumferential direction of the groove and an outer circumferential surface on a radially outer side of the permanent magnet 24.

  As described above, the gap 25 is formed in a groove shape cut out from the outer peripheral surface 23 c on the radially outer side of the rotor teeth 23 toward the permanent magnet 24. The air gap 25 functions as a high magnetic resistance region so that the main magnetic flux does not short-circuit between the adjacent stator teeth 13.

  The length of the gap 25 in the radial direction is set such that the end on the radially inner side is located closer to the permanent magnet 24 than at least the intermediate position between the outer peripheral surface 23c and the permanent magnet 24. . In the present embodiment, the radial length of the gap 25 is set to a length at which the radially inner end of the gap 25 reaches the permanent magnet 24. The radial length of the gap 25 may be set to a length such that the radially inner end of the gap 25 does not reach the permanent magnet 24.

  The width of the gap 25 in the circumferential direction is set to be at least as large as the distance between the inner peripheral surface of the stator teeth 13 and the outer peripheral surface of the rotor teeth 23. Accordingly, when the rotation speed of the rotor 20 is high, the gap 25 has a high magnetic resistance, and short-circuit of the main magnetic flux between the adjacent stator teeth 13 is suppressed.

(Magnetic path member)
As shown in FIG. 1, the magnetic path member 30 guides a part of the magnetic flux of the permanent magnet 24 to short-circuit between the rotor teeth 23 adjacent in the circumferential direction. Specifically, the magnetic path member 30 guides the magnetic flux generated by the permanent magnet 24 magnetized to the N pole as a short-circuited magnetic flux to the permanent magnet 24 magnetized to the S pole.

  The magnetic path members 30 are arranged on each q axis (see FIG. 3) between the rotor teeth 23 adjacent in the circumferential direction. The magnetic path member 30 is disposed with a gap G between the magnetic path member 30 and the rotor teeth 23 facing in the circumferential direction.

  The magnetic path member 30 is held between the rotor teeth 23 adjacent in the circumferential direction via an insulator 40 made of a non-magnetic material such as a resin, for example. As a result, the magnetic path member 30 rotates integrally with the rotor 20.

  The insulator 40 includes a holder portion 41 in which the magnetic path member 30 is accommodated, and a flange portion 42 integrally formed on a radially outer side of the holder portion 41.

  The rotor core 21 between the adjacent rotor teeth 23 is formed with a concave portion 21a into which a radially inner end of the holder portion 41 fits. On the circumferential side surface of the tip 23a of the rotor tooth 23, a groove 23b into which the circumferential end of the flange 42 fits is formed so as to extend in the axial direction.

  The insulator 40 is held between the adjacent rotor teeth 23 by the holder 41 being fitted into the recess 21 a and the flange 42 being fitted into the groove 23 b. Note that the magnetic path member 30 may be configured to be held on the rotating shaft of the rotor 20 or the rotor core 21 via a bracket or a connecting member (not shown) made of a non-magnetic material such as a resin, instead of the insulator 40. .

  When the magnetic path member 30 is held on the rotation axis of the rotor 20 or the rotor core 21 without using a nonmagnetic material, the magnetic coupling between the magnetic path member 30 and the rotation axis of the rotor 20 or the rotor core 21 is minimized. Preferably, they are connected to each other in a state.

  As described above, the magnetic path member 30 is disposed on the q axis in a state where the magnetic path member 30 is magnetically shielded from the rotor teeth 23 of the rotor core 21. As a result, the salient pole ratio is prevented from decreasing, and the reluctance torque is prevented from decreasing.

  The magnetic path member 30 is formed by stacking a plurality of electromagnetic steel sheets in the axial direction. The magnetic path member 30 may be formed by a dust core formed by compressing and hardening ferromagnetic fine powder.

  The variable field coil 35 is wound around the magnetic path member 30 in a toroidal shape in the axial direction. The variable field coil 35 is a coil that can adjust the amount of magnetic flux of the short-circuited magnetic flux that short-circuits between the adjacent permanent magnets 24 according to the magnitude of the induced current generated by the induction coil 22. The adjacent permanent magnets 24 are the permanent magnets 24 included in each of the rotor teeth 23 adjacent in the circumferential direction.

  The variable field coil 35 is toroidally wound around the magnetic path member 30 so as to form a magnetic pole in which the magnetic flux is short-circuited between the adjacent permanent magnets 24. Accordingly, when the DC current rectified by the rectifier circuit 50 described later is supplied, the variable field coil 35 generates an induced magnetic flux in such a direction that the magnetic flux is short-circuited between the adjacent permanent magnets 24, and the magnetic path member The magnetic poles are formed on 30. That is, the magnetic path member 30 is magnetized according to the direction of the induced magnetic flux generated by the variable field coil 35.

  Specifically, when a DC current is supplied to the variable field coil 35, as shown in FIG. 6, the magnetic path member 30 is magnetized to the N pole on the S pole permanent magnet 24 side, and the N pole permanent magnet The 24 side is magnetized to the S pole. As a result, a part of the magnetic flux of the N-pole permanent magnet 24 is short-circuited to the S-pole permanent magnet 24 via the magnetic path member 30.

  The amount of the induced magnetic flux generated by the variable field coil 35 is adjusted according to the magnitude of the DC current supplied to the variable field coil 35. By adjusting the amount of the induction magnetic flux, the amount of the short-circuit magnetic flux between the adjacent permanent magnets 24 is adjusted.

  The amount of the induced magnetic flux increases as the DC current supplied to the variable field coil 35 increases and as the number of turns of the variable field coil 35 increases. The number of turns of the variable field coil 35 is set to the number of turns experimentally obtained in advance.

  The DC current supplied to the variable field coil 35 is adjusted according to the magnitude of the induction current generated in the induction coil 22. Thus, the amount of the short-circuit magnetic flux is adjusted according to the magnitude of the induced current generated in the induction coil 22. The induction current generated in the induction coil 22 increases as the rotation speed of the rotor 20 increases. Therefore, the magnetic flux amount of the short-circuit magnetic flux increases as the rotation speed of the rotor 20 increases.

  A gap G having a predetermined size is formed between the magnetic path member 30 and the rotor teeth 23 as a region having a high magnetic resistance. The gap G is such that when no DC current is supplied to the variable field coil 35, the magnetic flux of the permanent magnet 24 does not flow between the rotor teeth 23 and the magnetic path member 30, or even if it does flow, the magnetic flux is minimal. Size. The gap G is set to a size such that the magnetic flux of the permanent magnet 24 flows between the rotor teeth 23 and the magnetic path member 30 when a DC current is supplied to the variable field coil 35.

(Rectifier circuit)
The rotating electric machine 1 includes a rectifier circuit 50 that rectifies an alternating current induced by the induction coil 22 into a direct current and supplies the direct current to the variable field coil 35.

  As shown in FIG. 3, the rectifying circuit 50 includes two diodes D1 and D2 as rectifying elements, and connects the diodes D1 and D2 to the two induction coils 22 and the two variable field coils 35. Is configured as

  The diodes D1 and D2 are provided on the rotor 20, for example, in a state housed in a diode case (not shown). The diodes D1 and D2 may be mounted inside the rotor 20.

  In the rectifier circuit 50, the AC induced current generated by the two induction coils 22 is rectified by the diodes D1 and D2, and the rectified DC current is applied to the two variable field coils 35 connected in series. Supplied as The two variable field coils 35 generate an induced magnetic flux when supplied with a direct current.

(Operation of rotating electric machine)
Next, the operation of the rotating electric machine 1 according to the present embodiment will be described with reference to FIGS.

  As described above, the rotating electric machine 1 according to the present embodiment is a permanent magnet type synchronous motor that includes the permanent magnet 24 on the rotor 20 and outputs torque using the magnetic flux of the permanent magnet 24.

  In the conventional permanent magnet type synchronous motor, since the magnetic flux of the permanent magnet is constant, the back electromotive force generated in the armature coil of the stator by the magnetic flux of the permanent magnet increases as the rotation speed of the rotor increases. When the rotation speed of the rotor reaches a certain rotation speed, the back electromotive force generated in the armature coil becomes equal to the power supply voltage of the permanent magnet type synchronous motor. As a result, no more current can flow through the permanent magnet type synchronous motor. As a result, the rotation speed of the rotor cannot be increased.

  Conventionally, in order to solve such a problem, field weakening control has been performed in which a back electromotive force generated in the armature coil is equivalently reduced by flowing a current through the armature coil of the stator to cancel the magnetic flux generated by the permanent magnet.

  However, this field-weakening control generates a magnetic flux that does not contribute to the torque because current flows to generate a magnetic flux in a direction to cancel the magnetic flux of the permanent magnet. This has led to a decrease in efficiency.

  Further, in the field-weakening control, since a harmonic magnetic flux is generated, there is a possibility that iron loss and electromagnetic vibration of the permanent magnet type synchronous motor increase due to the harmonic magnetic flux. Further, in the field-weakening control, a magnetic flux in a direction opposite to the magnetic flux of the permanent magnet is generated to suppress the magnetic flux of the permanent magnet, so that irreversible demagnetization of the permanent magnet may occur. For this reason, it is necessary to use a permanent magnet having a relatively high coercive force, which increases the cost.

  When a neodymium magnet is used as the permanent magnet, an eddy current is generated in the permanent magnet due to a change in the external magnetic field due to the field weakening control, and the permanent magnet generates heat. This heat may cause irreversible demagnetization of the permanent magnet. Therefore, it is necessary to add a material such as a rare earth having high heat resistance to the permanent magnet. However, in this case, since the added material such as rare earth becomes an impurity for the permanent magnet, there is a possibility that the intrinsic performance of the permanent magnet cannot be exhibited.

  Therefore, in the rotating electric machine 1 according to the present embodiment, the amount of magnetic flux linked from the permanent magnet 24 to the stator 10 is adjusted by the action of the magnetic path member 30 and the variable field coil 35 without performing the field weakening control. Possible configuration. Thereby, the rotating electric machine 1 according to the present embodiment can solve the problem caused by the field weakening control as described above.

(At low rotor speed)
In the rotating electric machine 1 according to the present embodiment, when the rotation speed of rotor 20 is low, the magnetic flux of the harmonic component is not generated in stator 10, or even if generated, the amount is small. For this reason, the variable field coil 35 does not generate an induced magnetic flux, or generates a very small amount even if it does.

  Therefore, the magnetic resistance is high in the gap G, and the magnetic pole member 30 does not have the N pole and the S pole. Therefore, the magnetic flux of the N-pole permanent magnet 24 does not short-circuit to the S-pole permanent magnet 24 via the magnetic path member 30 or only short-circuits. As a result, when the rotation speed of the rotor 20 is low, all or most of the magnetic flux of the permanent magnet 24 is linked to the stator 10 as shown in FIGS.

  As described above, when the rotation speed of the rotor 20 is low, the amount of magnetic flux linked to the stator 10 from the permanent magnet 24 can be increased as compared to when the rotation speed of the rotor 20 described later is high.

(At high rotor speed)
In the rotating electric machine 1 according to the present embodiment, when the rotation speed of rotor 20 is high, magnetic flux of a harmonic component is generated in stator 10. The amount of magnetic flux of the harmonic component increases as the rotation speed of the rotor 20 increases.

  The magnetic flux of the harmonic component is linked to the induction coil 22, so that an induction current is induced in the induction coil 22 (see FIG. 1) of the rotor 20, and the induced current is induced by the rectifier circuit 50 (see FIG. 3). The current is rectified and supplied to the variable field coil 35 as a direct current.

  The variable field coil 35 supplied with the DC current generates an induced magnetic flux such that the magnetic flux is short-circuited between the adjacent permanent magnets 24. That is, in the magnetic path member 30, the N pole and the S pole are formed such that the magnetic flux is short-circuited between the adjacent permanent magnets 24.

  As a result, a Halbach array in which the magnetization directions of the magnetic path member 30 and the permanent magnet 24 are different from each other by 90 ° is formed. Accordingly, the magnetic resistance in the gap G decreases. The Halbach array refers to an array in which magnets are arranged so that the magnetization directions differ by 90 ° between adjacent magnets.

  As described above, when the magnetic resistance in the gap G decreases, as shown in FIGS. 6 and 7, a part of the magnetic flux of the N-pole permanent magnet 24 becomes short-circuited magnetic flux via the magnetic path member 30 as the S-pole permanent magnet. Short to 24. Thereby, the magnetic flux of the magnetic flux amount excluding the short-circuit magnetic flux amount of the total magnetic flux amount of the magnetic flux of the permanent magnet 24 is linked to the stator 10. That is, when the rotation speed of the rotor 20 is high, the amount of magnetic flux linked to the stator 10 from the permanent magnet 24 is suppressed as compared with when the rotation speed of the rotor 20 is low.

  Therefore, even if the rotation speed of the rotor 20 is high, the field weakening control can be unnecessary. For this reason, it is possible to prevent iron loss and electromagnetic vibration caused by harmonic magnetic flux generated by the field weakening control.

  Further, since the field-weakening control is not required, there is no need to use a permanent magnet having a high coercive force, and it is not necessary to add a material such as a rare earth having high heat resistance to the permanent magnet. Thereby, the cost of the rotary electric machine 1 can be reduced.

  As described above, in the rotating electric machine 1 according to the present embodiment, the amount of magnetic flux linked from the permanent magnet 24 to the stator 10 can be adjusted without performing the field-weakening control. Specifically, when the rotation speed of the rotor 20 is high, a decrease in efficiency can be prevented. Further, when the rotation speed of the rotor 20 is low, the output can be improved.

(Operation of the void 25)
FIG. 8 shows the rotating electric machine 101 in which the air gap 25 is not formed. This rotating electric machine 101 is different from rotating electric machine 1 of the present embodiment in that gap 25 is not formed, but the other configuration is the same as rotating electric machine 1. The same reference numerals as in the present embodiment are used for the same configuration as rotating electric machine 1.

  As shown in FIG. 8, in the stator 10 in which the armature coils 11 are concentratedly wound, the magnetic poles of the adjacent stator teeth 13 are opposite magnetic poles. For this reason, a part of the main magnetic flux generated in the stator 10 is short-circuited between the adjacent stator teeth 13 through the rotor teeth 23 as shown by an arrow A in FIG.

  The amount of magnetic flux short-circuited between adjacent stator teeth 13 differs between when the rotor is rotating at a low speed and when the rotor is rotating at a high speed. At the time of low rotation of the rotor, the amount of magnetic flux linked from the permanent magnet 24 to the stator 10 is large, and thus the magnetic flux of the permanent magnet 24 acts to cancel the main magnetic flux short-circuited between the adjacent stator teeth 13. This suppresses the amount of magnetic flux short-circuited between the adjacent stator teeth 13 during low rotation of the rotor.

  As described above, the amount of magnetic flux linked from the permanent magnet 24 to the stator 10 at the time of high rotation of the rotor decreases, and therefore, the amount of magnetic flux short-circuited between the adjacent stator teeth 13 increases as compared with the time of low rotation of the rotor. .

  Here, in the armature coil 11, the magnetic flux of the permanent magnet 24 and the main magnetic flux short-circuited between the adjacent stator teeth 13 as described above are linked. The induced electromotive force generated in the armature coil 11 is obtained by time-differentiating Φ when the total amount of magnetic flux linked to the armature coil 11 is “Φ”. That is, the induced electromotive force V generated in the armature coil 11 is “V = −dΦ / dt”.

  For this reason, if the amount of magnetic flux short-circuited between adjacent stator teeth 13 increases even though the amount of magnetic flux of the permanent magnet 24 is reduced, the total number of magnetic fluxes linked to the armature coil 11 is reduced. You will not be able to do it.

  As a result, when the rotor rotates at a high speed, the induced electromotive force generated in the armature coil 11 does not decrease even though the amount of magnetic flux of the permanent magnet 24 is reduced.

  In the rotating electrical machine 1 according to the present embodiment, the above-described groove-shaped gap 25 is formed in rotor teeth 23 so that the main magnetic flux does not short-circuit between adjacent stator teeth 13 during high rotation of the rotor. The air gap 25 functions as a region of high magnetic resistance when the rotor rotates at a high speed, thereby suppressing a short circuit of the main magnetic flux between the adjacent stator teeth 13.

  As described above, according to the rotating electric machine 1 of the present embodiment, an induction current is generated by linking the harmonic component superimposed on the magnetic flux generated on the stator 10 side to the induction coil 22, and the induction current is generated. Is rectified by the rectifier circuit 50 and supplied to the variable field coil 35. Thereby, the amount of magnetic flux of the short-circuited magnetic flux that short-circuits between the permanent magnets 24 adjacent in the circumferential direction can be adjusted.

  A harmonic component superimposed on the magnetic flux generated on the stator 10 side is obtained by supplying a three-phase alternating current to the armature coil 11 concentratedly wound on the stator 10. For this reason, a special device such as a DC / DC converter is not required to generate the DC current supplied to the variable field coil 35.

  Thereby, the rotating electric machine 1 of the present embodiment adjusts the amount of magnetic flux of the magnetic flux linked from the permanent magnet 24 to the stator 10 with a simple configuration without using a special device such as a DC / DC converter. be able to. As a result, the rotating electric machine 1 of the present embodiment can change the magnetic flux of the permanent magnet 24 with a low-cost configuration.

  Further, in rotating electric machine 1 of the present embodiment, since groove-shaped gap 25 is formed in rotor teeth 23, it is possible to suppress a short circuit of the main magnetic flux between adjacent stator teeth 13 during high rotation of the rotor. . Thereby, the total number of magnetic fluxes linked to the armature coil 11 at the time of high rotation of the rotor can be reduced. Therefore, at the time of high rotation of the rotor, the induced electromotive force generated in the armature coil 11 can be reduced.

  The rotating electric machine 1 can be suitably adopted, for example, as a motor for a vehicle, a generator for a wind power generator, or a motor for a machine tool.

  In the present embodiment, the rotating electric machine 1 is applied to a radial gap type rotating electric machine, but may be applied to an axial gap type rotating electric machine.

  In the rotating electric machine 1 of the present embodiment, if the ratio of the number of the slots 14 of the stator 10 to the number of the rotor teeth 23 of the rotor 20, that is, the slot combination of the stator 10 and the rotor 20 is “3: 2”, The combination of the number 14 and the number of the rotor teeth 23 may be any combination.

  Further, rotating electric machine 1 of the present embodiment may employ rotor 220 shown in FIG. As shown in FIG. 9, rotor 220 differs from the present embodiment in the shape of the void formed in rotor teeth 23.

  In the rotor teeth 23 of the rotor 220, a gap 225 extending in the axial direction is formed radially outward of the permanent magnet 24. The gap 225 is formed in a tapered shape in which the width in the circumferential direction is reduced from the radially outer side of the rotor teeth 23 toward the permanent magnet 24.

  The gap 225 shown in FIG. 9 employs a triangular shape as a tapered shape. The tapered shape is not limited to a triangular shape, but may be any of various shapes such as a trapezoidal shape, a semicircular shape, and a warhead shape, as long as the circumferential width decreases from the radially outward side toward the inward side. Shapes can be employed.

  Further, in the example shown in FIG. 9, a bridge portion 223 c that forms the outer peripheral portion of the rotor tooth 23 is formed on the radially outer side of the gap 225. The bridge portion 223c is provided to maintain the strength of the rotor teeth 23, but may not be provided when the strength of the rotor teeth 23 is sufficiently ensured.

  While embodiments of the present invention have been disclosed, it will be apparent that modifications may be made by those skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

REFERENCE SIGNS LIST 1 rotating electric machine 10 stator 11 armature coil 12 stator core 13 stator teeth 14 slot 20, 220 rotor 21 rotor core 22 induction coil 23 rotor teeth 23a tip 23c outer peripheral surface 24 permanent magnet 25, 225 air gap 30 magnetic path member 35 variable field coil 50 Rectifier circuit D1, D2 Diode G Clearance

Claims (3)

A rotating electric machine including a stator having an armature coil and a rotor having a permanent magnet,
The stator is
The armature coil has a plurality of stator teeth wound concentratedly,
The rotor,
A plurality of rotor teeth containing the permanent magnet,
An induction coil wound around the rotor teeth on the stator side relative to the permanent magnet,
Between the rotor teeth adjacent in the circumferential direction, a magnetic path member is disposed via a gap,
The magnetic path member is provided with a variable field coil capable of adjusting a magnetic flux amount of a magnetic flux that is short-circuited between the circumferentially adjacent permanent magnets based on an induction current generated in the induction coil,
A rotating electric machine, wherein a gap extending in the axial direction is formed in the rotor teeth on a radially outer side of the permanent magnet.   2. The rotating electric machine according to claim 1, wherein the gap is formed in a groove shape cut out from an outer peripheral surface on a radially outer side of the rotor teeth toward the permanent magnet. 3. The said gap | gap is formed in the taper shape which becomes small in the circumferential direction as it goes to the said permanent magnet side from the radially outer side of the said rotor teeth, The said 1 or 2 characterized by the above-mentioned. The rotating electric machine as described.

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