JP6984164B2 - Rotating machine - Google Patents

Description

The present invention relates to a rotary electric machine.

Permanent magnet type synchronous motors are known as rotary electric machines used as drive sources for vehicles such as hybrid vehicles and electric vehicles. The operating point of the permanent magnet type synchronous motor differs depending on the running condition of the vehicle. For example, the operating point in the high torque region is used when the vehicle starts, the operating point in the low torque region is used when the vehicle is traveling in the city, and the operating point in the high speed region is used when the vehicle is traveling at high speed.

As a conventional rotary electric machine of this kind, the one described in Patent Document 1 is known. The one described in Patent Document 1 includes a bypass path for bypassing the magnetic flux of a permanent magnet from one magnetic pole formed by a rotor to another magnetic pole.

Japanese Patent No. 6033424

By the way, in a rotary electric machine provided with a bypass path like the rotary electric machine described in Patent Document 1, the amount of magnetic flux of a permanent magnet passing through the bypass path is strengthened by the magnetic flux of the armature coil so that a desired operating point can be obtained. It is conceivable to perform strong field control.

However, in the rotary electric machine described in Patent Document 1, since the magnetic flux of the permanent magnet is linked to the stator in a sinusoidal manner, the armature is rotated at high speed in a no-load state in which no current is passed through the armature coil. An induced voltage is generated in the coil. When an induced voltage is generated in the armature coil, the motor rotation speed must be limited so that the induced voltage does not exceed the power supply voltage of the inverter, and the operating point of the motor becomes narrow.

Further, in the rotary electric machine described in Patent Document 1, since a permanent magnet having a high magnetoresistance is arranged on the d-axis and an outer magnetic gap portion is arranged on the q-axis, the d-axis and the q-axis are arranged. The magnetic resistances of the d-axis and the q-axis become the same, the reluctance ratio, which is the magnetic resistance ratio of the d-axis and the q-axis, decreases, and the reluctance torque decreases.

Therefore, in the rotary electric machine described in Patent Document 1, the operating point of the motor is narrowed, the reluctance torque cannot be effectively utilized, and the output torque and the efficiency are lowered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotary electric machine capable of widening an operating point and increasing a reluctance torque.

The present invention is a rotary electric machine including a stator having an armature coil and a rotor having a rotor core and a plurality of salient poles provided on a surface of the rotor core facing the stator in order to achieve the above object. The rotor is arranged in the first bypass path connecting the adjacent salient poles and the first bypass path at a position closest to the axis so as to face the magnetic pole in the extending direction of the first bypass path. It is characterized by comprising a first permanent magnet and a first flux barrier formed between the rotor core and the first bypass path.

According to the present invention, the operating point can be widened and the reluctance torque can be increased.

FIG. 1 is a cross-sectional view of a rotary electric machine according to an embodiment of the present invention cut along a plane orthogonal to a rotation axis. FIG. 2 is an enlarged cross-sectional view of a part of the rotary electric machine according to the embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of a part of the rotary electric machine according to the embodiment of the present invention. FIG. 4 is a magnetic flux diagram illustrating the effect of the concave portion on the outer peripheral surface of the rotor in the rotary electric machine according to the embodiment of the present invention. FIG. 5 is a magnetic flux diagram illustrating the effect of the cutout portion of the fourth bypass path in the rotary electric machine according to the embodiment of the present invention. FIG. 6 is a cross-sectional view showing a bridge portion of a rotor of a rotary electric machine according to an embodiment of the present invention. FIG. 7 is a cross-sectional view showing a locking portion of a rotor of a rotary electric machine according to an embodiment of the present invention. FIG. 8 is a magnetic flux vector diagram showing a magnetic flux vector at the time of a strong field in the rotary electric machine according to the embodiment of the present invention. FIG. 9 is a magnetic flux vector diagram showing a magnetic flux vector at the time of field weakening in the rotary electric machine according to the embodiment of the present invention.

The rotary electric machine according to the embodiment of the present invention is a rotary electric machine including a stator having an armature coil and a rotor core and a rotor having a plurality of salient poles provided on facing surfaces of the rotor core with respect to the stator. The rotor includes a first bypass path connecting adjacent salient poles, a first permanent magnet arranged in the first bypass path so as to face a magnetic pole in the extending direction of the first bypass path, a rotor core, and a first rotor. It is characterized by including a first flux barrier formed between the bypass path and the bypass path. As a result, the rotary electric machine according to the embodiment of the present invention can have a wide operating point and can increase the reluctance torque.

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

As shown in FIGS. 1, 2, and 3, the rotary electric machine 1 according to the present embodiment is an embedded magnet synchronous rotary electric machine (IPMSM: Interior Permanent Magnet Synchronous Motor) in which a permanent magnet is embedded in a rotor. The rotary electric machine 1 has a performance suitable for mounting on, for example, a hybrid vehicle or an electric vehicle.

The rotary electric machine 1 includes a stator 10 formed in an annular shape and a rotor 20 rotatably housed in the stator 10. The rotor 20 is fixed to a rotating shaft 2 that rotates about the axis O, and rotates integrally with the rotating shaft 2.

The stator 10 is fixed to a motor case (not shown). The stator 10 includes an annular stator core 11 made of a magnetic material having a high magnetic permeability. The stator core 11 is formed by laminating electromagnetic steel sheets in the axial direction along the axis of the rotating shaft 2.

The stator core 11 is provided with a plurality of stator teeth 12 (48 in this embodiment) protruding inward in the radial direction along the circumferential direction. Slots 13, which are groove-shaped spaces, are formed between the stator teeth 12 adjacent to each other in the circumferential direction.

Here, the radial direction indicates a direction orthogonal to the above-mentioned axial direction. The radial inner side indicates the side closer to the rotating shaft 2 in the radial direction, and the radial outer side indicates the side farther from the rotating shaft 2 in the radial direction. The circumferential direction indicates a circumferential direction about the rotation axis 2.

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

The stator 10 generates a rotating magnetic field that rotates in the circumferential direction by supplying a three-phase alternating current to the armature coil 14. The magnetic flux generated in the stator 10 is coupled to the rotor 20. As a result, the stator 10 can rotate the rotor 20.

An armature coil 14 is connected to an inverter (not shown) for controlling the current flowing through the armature coil 14, and the inverter is a three-phase alternating current supplied to the armature coil 14, that is, a supply armature. Controls the amplitude and phase of the current.

The amplitude and phase of the armature current are appropriately controlled within the range that meets the required operating point. Depending on the power efficiency of the motor, only one of the amplitude and the phase may be controlled at any given time, or both may be controlled.

The rotor 20 includes an annular rotor core 21. The rotor core 21 is formed by laminating an electromagnetic steel plate, which is a magnetic material having a high magnetic permeability, in the axial direction along the axis of the rotating shaft 2.

A plurality (eight) salient poles 22 are formed at equal intervals on the outer peripheral surface of the rotor core 21 along the circumferential direction of the rotor 20. The salient pole 22 projects outward in the radial direction, that is, in the direction of the stator 10. The adjacent salient poles 22 are separated by a mechanical angle of 45 [deg] in the circumferential direction.

Here, the rotor core 21 and the salient pole 22 are integrally formed and are magnetically coupled. Therefore, the rotor core 21 in this embodiment functions as a yoke portion, and mechanically and magnetically couples the base portions of the plurality of salient poles 22.

In this embodiment, the axis passing through the salient pole 22 is defined as the d-axis, and the axis electrically and magnetically orthogonal to the d-axis (the axis separated by 90 [deg] in electrical angle) is defined as the q-axis. The q-axis is separated from the d-axis by a mechanical angle of 22.5 [deg] in the circumferential direction, and passes through the middle of the salient poles 22 adjacent to each other in the circumferential direction. The salient pole 22 is a magnetic path through which magnetic flux passes, and the salient pole 22 is hereinafter also referred to as a salient pole magnetic path or a d-axis magnetic path.

In the rotary electric machine 1 according to the present embodiment, the rotor 20 includes a first bypass path BP1 that connects adjacent salient poles 22 to each other.

The first bypass path BP1 connects the base ends of the salient pole 22 on the rotor core 21 side, and extends linearly in parallel with the tangent line of the rotor 20.

The rotor 20 includes a first permanent magnet PM1 arranged in the first bypass path BP1 so as to face a magnetic pole in the extending direction of the first bypass path BP1. The first permanent magnet PM1 comprises one permanent magnet which is not divided in this embodiment.

The rotor 20 includes a first flux barrier FB1 formed between the rotor core 21 and the first bypass path BP1.

The first flux barrier FB1, the second flux barrier FB2, the third flux barrier FB3, the fourth flux barrier FB4, and the fifth flux barrier FB5, which will be described later, prevent the wraparound of the magnetic flux, and are substances having a low magnetic permeability (the present). In the embodiment, it is composed of air).

A second flux barrier FB2 is provided at the base end of the salient pole 22. The second flux barrier FB2 is arranged at a connecting portion with the rotor core 21 at the base end portion of the salient pole 22. The second flux barrier FB2 is formed in a triangular shape so that the base end portion of the salient pole 22 is diagonally connected to the rotor core 21.

Between adjacent salient poles 22 and on the stator 10 side of the first bypass path BP1, the other salient pole 22 straddles the q-axis from the vicinity of one salient pole 22 on the surface of the rotor 20 facing the stator 10. A second bypass path BP2 extending toward the vicinity of the above is provided.

The second bypass path BP2 extends radially inward in parallel with the salient pole 22 in the vicinity of the tip of one salient pole 22 on the outer peripheral surface of the rotor 20, and then straddles the q-axis and the other salient pole 22. It is curved and extended in a U-shape toward the direction of, and reaches the vicinity of the tip of the other salient pole 22.

In other words, the second bypass path BP2 is U-shaped so as to go from the side of the tip of one of the adjacent salient poles 22 to the side of the tip of the other salient pole 22 through the inner peripheral side of the rotor core 21. It is curved like a shape.

Here, since the rotor 20 of this embodiment is an inner rotor type radial gap rotor, the “opposing surface” of the rotor 20 with the stator 10 means the outer peripheral surface of the rotor 20. If the rotor 20 is an outer rotor type radial gap rotor, the inner peripheral surface of the rotor 20 constitutes a facing surface with the stator 10. When the rotor 20 is an axial gap rotor, the surface facing the stator 10 in the axial direction constitutes the facing surface.

Further, the range of the “nearby” of the salient poles 22 is between the salient poles 22 adjacent to each other, and is between the salient poles 22 and the q-axis, which are the d-axis. That is, the vicinity of one or the other salient pole 22 means the space between the salient pole 22 and the q-axis.

Further, in the second bypass path BP2, the second permanent magnet PM2 is arranged so as to face the magnetic pole in the extending direction of the second bypass path BP2. The second permanent magnet PM2 is a set of permanent magnets arranged so as to face each other across the q-axis.

Further, a third flux barrier FB3 is provided between the first bypass path BP1 and the second bypass path BP2.

When the width of the third flux barrier FB3 in the vicinity of the stator 10 is Wb, the width of the third flux barrier FB3 in the vicinity of the q-axis is Wq, and the tooth spacing of the portion of the stator 10 facing the rotor 20 is Ws. Wb <Ws and Wb <Wq are satisfied. Here, the tooth spacing is the opening width of the slot 13, that is, the spacing between adjacent stator teeth 12.

Here, by narrowing the width of the second bypass path BP2 in the vicinity of the q-axis to such an extent that magnetic saturation is not caused, the width Wq can be expanded to a desired size.

Between adjacent salient poles 22 and on the stator 10 side of the second bypass path BP2, the other salient pole 22 straddles the q-axis from the vicinity of one salient pole 22 on the surface of the rotor 20 facing the stator 10. A third bypass path BP3 extending toward the vicinity of the above is provided. Further, a fourth flux barrier FB4 is provided between the second bypass path BP2 and the third bypass path BP3.

The third bypass path BP3 extends radially inward in parallel with the salient pole 22 in the vicinity of the tip of one salient pole 22 on the outer peripheral surface of the rotor 20, and then straddles the q-axis and the other salient pole 22. It is curved and extended in a U-shape toward the direction of, and reaches the vicinity of the tip of the other salient pole 22.

In other words, the third bypass path BP3 is U-shaped so as to go from the side of the tip of one of the adjacent salient poles 22 to the side of the tip of the other salient pole 22 through the inner peripheral side of the rotor core 21. It is curved like a shape.

Between adjacent salient poles 22 and on the stator 10 side of the third bypass path BP3, the other salient pole 22 straddles the q-axis from the vicinity of one salient pole 22 on the surface of the rotor 20 facing the stator 10. A fourth bypass path BP4 extending toward the vicinity of the above is provided.

The fourth bypass path BP4 extends radially inward in parallel with the salient pole 22 in the vicinity of the tip of one salient pole 22 on the outer peripheral surface of the rotor 20, and then straddles the q-axis and the other salient pole 22. It is curved and extended in a U-shape toward the direction of, and reaches the vicinity of the tip of the other salient pole 22.

In other words, the fourth bypass path BP4 is U-shaped so as to go from the side of the tip of one of the adjacent salient poles 22 to the side of the tip of the other salient pole 22 through the inner peripheral side of the rotor core 21. It is curved like a shape.

Further, a fifth flux barrier FB5 is provided between the third bypass path BP3 and the fourth bypass path BP4.

Further, in the fourth bypass path BP4, a third permanent magnet PM3 is arranged so as to face the magnetic pole in the extending direction of the fourth bypass path BP4. The third permanent magnet PM3 is a set of permanent magnets arranged so as to face each other across the q-axis.

Further, the fourth bypass path BP4 has a recess 25 recessed from the outer peripheral surface of the rotor 20 toward the rotor core 21 on the q-axis. The recess 25 is arranged at a portion of the fourth bypass path BP4 that forms the outer peripheral surface of the rotor 20.

At the end of the fourth bypass path BP4 on the stator 10 side, a notch 24 forming a predetermined angle with respect to the tangent to the outer peripheral surface of the rotor 20 is formed. The notch portion 24 has a concave shape corresponding to the claw shape by forming the end portion of the fifth flux barrier FB 5 on the stator 10 side so as to project into a claw shape.

The pair of second permanent magnets PM2 and the pair of third permanent magnets PM3 that are adjacent to each other with one of the adjacent salient poles 22 sandwiched are arranged so that the outer peripheral side of the rotor 20 is the north pole. Further, the pair of second permanent magnets PM2 and the pair of third permanent magnets PM3 that are adjacent to each other with the other of the adjacent salient poles 22 interposed therebetween are arranged so that the outer peripheral side of the rotor 20 is the other side of the S pole. .. Therefore, in the rotor 20, the salient poles 22 of the N pole and the salient poles 22 of the S pole are alternately arranged in the circumferential direction.

A pair of air layers 23 are provided in the vicinity of the surface of the rotor 20 and surrounded by the fourth bypass path BP4 with the q-axis interposed therebetween, and the air layers 23 prevent the magnetic flux from wrapping around.

Here, the first permanent magnet PM1, the second permanent magnet PM2, and the third permanent magnet PM3 are formed in the shape of a rectangular parallelepiped. In this embodiment, the length in the direction orthogonal to the magnetizing direction of the second permanent magnet PM2 is larger than the length in the direction orthogonal to the magnetizing direction of the permanent magnet PM1. Further, the length in the direction orthogonal to the magnetizing direction of the third permanent magnet PM3 is larger than the length in the direction orthogonal to the magnetizing direction of the second permanent magnet PM2. Further, the length of the third permanent magnet PM3 in the magnetizing direction is smaller than the length of the second permanent magnet PM2 in the magnetizing direction.

Next, the operation and action / effect of the rotary electric machine 1 according to this embodiment will be described.

As described above, in this embodiment, the first bypass path BP1, the second bypass path BP2, and the fourth bypass path BP4, which are bypass paths provided with permanent magnets, have a three-layer structure. As a result, the magnetic flux of the first permanent magnet PM1, the magnetic flux of the second permanent magnet PM2, and the magnetic flux of the third permanent magnet PM3 form the first bypass path BP1, the second bypass path BP2, and the fourth bypass path BP4, respectively. It becomes easy to flow through, and these magnet magnetic fluxes can be easily short-circuited in the rotor 20. The magnet magnetic flux of the first permanent magnet PM1, the magnet magnetic flux of the second permanent magnet PM2, and the magnet magnetic flux of the third permanent magnet PM3 are collectively referred to as a magnet magnetic flux.

The first flux barrier FB1, the third flux barrier FB3, and the fourth flux barrier FB4 straddle the q-axis, and the first permanent magnet PM1 is arranged on the q-axis. Therefore, it is difficult for the magnetic flux to pass in the q-axis direction. On the other hand, the magnetic flux easily passes through the d-axis having the salient pole 22.

That is, the inductance in the d-axis direction (d-axis inductance Ld) passing through the salient pole 22 is larger than the inductance in the q-axis direction (q-axis inductance Lq). Therefore, the rotor 20 has a structure having a forward polarity) (Ld> Lq) (hereinafter, also referred to as a forward polarity structure), and has a reverse polarity (Ld <Lq) generally used in hybrid vehicles and the like today. It is different from the rotary electric machine having a structure (hereinafter, also referred to as a reverse salient pole structure).

By forming the rotor 20 into a forward inductance structure in this way, the rotary electric machine 1 of the present embodiment has a magnet torque generated by the first permanent magnet PM1, the second permanent magnet PM2, and the third permanent magnet PM3, in addition to the magnet torque generated by the first permanent magnet PM1 and the second permanent magnet PM3. Reluctance torque can be generated according to the difference between the d-axis inductance Ld and the q-axis inductance Lq.

Since the rotary electric machine 1 of this embodiment includes a rotor 20 having a structure having a forward collision polarity (Ld> Lq), the armature current (id) and the q-axis current (iq) are represented on the d−q coordinates. In the vector diagram, the current vector is driven so as to be arranged in the first quadrant (+ id and + iq) in which the d-axis current (id) has a positive value and the q-axis current (iq) has a positive value.

That is, in this rotary electric machine 1, torque can be generated while performing a strong field by energizing a d-axis current (id) as a rotor field current in the same direction as the magnet magnetic flux vector. That is, the rotor field amount can be adjusted by adjusting the amplitude of the d-axis current (id).

On the other hand, in the reverse salient pole structure, the negative d-axis current (-id) increases the d-axis current vector so that it becomes a countermagnetic field with respect to the magnet magnetic flux vector of the rotor 20, and the field is weakened by the cancellation of the magnetic flux. Realizes magnetism.

However, the rotary electric machine having the reverse polarity uses a negative d-axis current (-id) that does not contribute to the torque due to the field weakening, so that the efficiency deteriorates. Further, in the rotary electric machine having the reverse polarity, the iron loss is greatly increased due to the large distortion of the magnetic flux waveform. Further, in a rotary electric machine having a reverse polarity, spatial harmonics increase due to distortion of the magnetic flux waveform, and torque ripple, electromagnetic vibration and vibration increase.

On the other hand, since the rotary electric machine 1 of the present embodiment has a forward polarity, the positive d-axis current (+ id) is reduced (advanced to the q-axis side or the amplitude is reduced). The amount of d-axis magnetization can be adjusted. Therefore, the d-axis current that does not directly contribute to the torque is reduced, and the efficiency can be increased.

If it is more efficient to drive with a field weakening with a negative d-axis current (-id) than to reduce the positive d-axis current (+ id), it may be driven with a field weakening. Even if it is driven by a weak field, the current value of the negative d-axis current (-id) can be reduced by the effect of the leakage flux as compared with the conventional technique, so that the efficiency is improved.

Further, since the third bypass path BP3 is provided between the second bypass path BP2 and the fourth bypass path BP4, the rotor 20 has a structure in which a multi-layer magnet magnetic path and a multi-layer salient pole magnetic path are alternately formed. It has become. Here, in the rotary electric machine 1, the line voltage of each phase of the armature coil 14 is restricted by the DC bus voltage.

In this embodiment, when the line voltage reaches the voltage limit, the magnetic flux leaks to the salient pole magnetic path due to the reverse magnetic field due to the negative d-axis current (-id), and a short-circuit magnetic path is formed in the rotor 20. Ru. As a result, the amount of magnetic flux interlinking with the armature coil 14 can be significantly reduced, and a wide variable field characteristic can be obtained.

Further, in this embodiment, since the magnetic poles of the first permanent magnet PM1, the second permanent magnet PM2, and the third permanent magnet PM3 are arranged as shown in FIGS. The salient poles 22 of the poles are alternately arranged in the circumferential direction of the rotor 20.

In such a rotary electric machine 1, when driving in a strong field region where a positive d-axis current (+ id) is obtained, the magnetic flux generated by the armature coil 14 of the stator 10 in the d-axis magnetic path having the largest inductance (hereinafter,). , Also called armature magnetic flux), and a magnetic circuit is constructed with the magnetic magnetic path as a bypass path.

On the other hand, when the rotary electric machine 1 is driven in the field weakened field region where the negative d-axis current (-id) is obtained, the armature magnetic flux in the direction opposite to the magnet magnetic flux vector is interlinked with the d-axis magnetic path having the largest inductance. do. Then, a leakage flux path of the magnet magnetic flux is formed in the salient magnetic path whose magnetic resistance is smaller than that of the stator 10 in which the reverse magnetic field generated by the negative d-axis current (-id) is generated.

Therefore, the magnet magnetic flux is short-circuited in the rotor 20. Due to such a leakage flux effect, the magnetic flux interlinking from the rotor 20 to the stator 10 (hereinafter, also referred to as armature interlinkage magnetic flux) can be reduced, and a variable field effect can be obtained.

Further, in this embodiment, a bypass path for the magnetic magnetic path is provided at the innermost inner diameter portion of the rotor 20 in the salient pole magnetic path.

As a result, when the field is driven to have a positive d-axis current (+ id), the field is strengthened so that the amount of magnetic flux interlinking with the armature coil 14 increases due to the magnetic flux assist effect of the + d-axis magnetic flux. ..

On the other hand, when the field is weakened to have a negative d-axis current (-id), the magnet magnetic flux on the magnet bypass path is caused by the reverse field effect due to the -id axis magnetic flux, and the innermost portion of the rotor 20 in the salient pole magnetic path. A short-circuit magnetic path is formed so as to be short-circuited to.

Therefore, as compared with the case where the bypass path of the magnetic magnetic path is not formed, the torque can be improved at the time of strong field, and the armature interlinkage magnetic flux can be significantly reduced at the time of weak field.

Further, in this embodiment, by providing the recess 25 on the q-axis of the outer circumference of the rotor 20, the magnetic resistance in the q-axis can be increased, and a magnetic flux is formed as shown in FIG. Therefore, the q-axis inductance can be reduced, and the difference (Ld-Lq) from the d-axis inductance can be improved. As a result, the salient pole ratio can be increased and the reluctance torque can be improved.

Further, in this embodiment, a notch portion 24 forming a predetermined angle with respect to the tangent line to the outer peripheral surface of the rotor 20 is formed at the end portion of the fourth bypass path BP4 on the stator 10 side. By forming this notch portion 24, as shown in FIG. 5, the direction of the magnetic flux from the fourth bypass path BP4 toward the stator 10 can be changed from the radial outer direction to the circumferential direction, and the circumferential direction can be changed. The electromagnetic force can be improved and the torque can be improved.

Further, in this embodiment, as shown in FIG. 6, a bridge portion 27 is provided in the first bypass path BP1 and a bridge portion 26 is provided in the second bypass path BP2.

When there is no load, the magnetic flux is short-circuited to the assault magnetic path via the bridge portion 27 of the first bypass path BP1 and the bridge portion 26 of the second bypass path BP2. The bridge portions 27 and 26 are arranged on the outer diameter side of the first permanent magnet PM1 and the second permanent magnet PM2 in the first bypass path BP1 and the second bypass path BP2, respectively, and the first bypass path BP1 and the second bypass It has a function of ensuring the mechanical strength of the road BP2.

That is, the first permanent magnet PM1 and the second permanent magnet PM2 can be supported in the radial direction by these bridge portions 27 and 26. Therefore, the centrifugal force acting on the first permanent magnet PM1 and the second permanent magnet PM2 can be assigned to the bridge portions 27 and 26, and the resistance of the first permanent magnet PM1 and the second permanent magnet PM2 to the centrifugal force can be increased. Can be improved.

In this embodiment, since the magnet magnetic flux is short-circuited to the assault magnetic path via the bridge portions 26 and 27, the amount of magnetic flux interlinking with the stator can be reduced, iron loss can be reduced when there is no load, and cogging torque can be reduced. It can be reduced and the induced voltage can be reduced.

The heat generated by the eddy currents in the first permanent magnet PM1 and the second permanent magnet PM2 can be dissipated on the open surface on the inner diameter side of the first permanent magnet PM1 and the second permanent magnet PM2. Further, the heat generated by the eddy current can be dissipated through the bridge portions 27 and 28 on the outer diameter side of the first permanent magnet PM1 and the second permanent magnet PM2.

Further, in this embodiment, as shown in FIG. 7, a claw-shaped locking portion 30 is provided on the first bypass path BP1, a claw-shaped locking portion 29 is provided on the second bypass path BP2, and the fourth bypass path BP4 is provided. Is provided with a claw-shaped locking portion 28. As a result, the assembling property of the first permanent magnet PM1, the second permanent magnet PM2, and the third permanent magnet PM3 can be improved, and the first permanent magnet PM1, the second permanent magnet PM2, and the third permanent magnet PM3 can be improved without using a special jig. Positioning of the permanent magnet PM3 can be easily performed.

Further, in this embodiment, as shown in FIG. 2, the width (Wb) of the third flux barrier FB3, the fourth flux barrier FB4, and the fifth flux barrier FB5 is made smaller than the opening width (Ws) of the slot 13. There is. For example, when Ws is 1.8 mm, Wb is 1.0 mm.

By doing so, as shown in FIGS. 2 and 8, the reluctance torque can be improved by increasing the salient pole ratio of Ld> Lq at the time of strong field. Further, since the opening width (Ws) of the slot 13 is larger than the width (Wb) of the flux barrier, as shown in FIGS. 2 and 9, the magnet magnetic flux passes through the gap with the stator 10 at the time of field weakening. Rather than interlinking with the stator 10, it is more likely to pass through the third flux barrier FB3, the fourth flux barrier FB4, and the fifth flux barrier FB5 in the rotor 20 to become a leakage flux. As a result, a large amount of magnetic flux can be leaked into the rotor 20 when driving in the field weakening region, and the magnetic flux interlinking with the stator 10 can be significantly reduced.

As described above, in the rotary electric machine 1 according to the present embodiment, the rotor 20 extends the first bypass path BP1 to the first bypass path BP1 connecting the adjacent salient poles 22 to each other and the first bypass path BP1. It includes a first permanent magnet PM1 arranged so as to face a magnetic pole in the direction, and a first flux barrier FB1 formed between the rotor core 21 and the first bypass path BP1.

As a result, as shown in FIG. 9, the adjacent salient poles 22, the first bypass path BP1 and the rotor core 21 form a magnetic flux bypass circuit that orbits around the first flux barrier FB1.

Therefore, the magnetic flux of the first permanent magnet PM1 is likely to be short-circuited in the rotor 20, so that the amount of magnetic flux interlinking with the stator 10 can be reduced. Further, when the rotor 20 is rotating at high speed in a no-load state where the armature coil 14 is not energized, the induced voltage generated in the armature coil 14 can be reduced, and the permissible rotation speed in the no-load state can be expanded. Can be done. Therefore, the operating point can be widened.

Further, as shown by the broken line arrow A in FIG. 1, the magnetic flux of the armature coil 14 wraps around from one adjacent salient pole 22 to a deep part of the core 21 of the rotor 20 and then reaches the other salient pole 22. Therefore, the reluctance torque can be increased. Here, the "deep portion" of the rotor 20 is a position on the axial center O (see FIG. 1) side of the first flux barrier FB1. In other words, the "deep part" of the rotor 20 is a portion of the core 21 of the rotor 20 that is far from the stator 10. When the present invention is applied to an outer rotor type radial gap rotor, the portion of the core of the outer rotor that is far from the stator in the outer peripheral direction becomes the deep part. Further, when the present invention is applied to the axial gap rotor, the portion of the core of the axial gap rotor on the side farther in the axial direction from the stator becomes the deep part.

As a result, the operating point can be widened and the reluctance torque can be increased.

Further, in the rotary electric machine 1 according to the present embodiment, the second flux barrier FB2 is provided at the base end portion of the salient pole 22.

By providing the second flux barrier FB2 at the base end portion of the salient pole 22 in this way, the base end portion of the salient pole 22 has a structure in which the base end portion thereof branches in the circumferential direction with the second flux barrier FB2 as a boundary. Therefore, each magnetic flux short-circuit path of the first permanent magnet PM1 of the two first bypass paths BP1 adjacent to each other in the circumferential direction with the salient pole 22 interposed therebetween can be magnetically separated.

Therefore, it is possible to prevent the magnetic fluxes passing through the respective magnetic flux short-circuit paths from colliding and interfering with each other at the proximal end portion of the salient pole 22 in an attempt to reduce the overlapping range of the two magnetic flux short-circuit paths. Therefore, it is possible to prevent the magnetic resistance of the magnetic flux short-circuit path from increasing at the base end portion of the salient pole 22 due to collision and interference between the magnetic fluxes and reducing the short-circuit magnetic flux amount. Further, it is possible to prevent the magnetic flux that could not be short-circuited from being short-circuited at another location or interlinking with the stator 10.

Further, as shown in FIG. 8, the magnetic flux of the armature coil 14 can smoothly merge at the base end portion of the salient pole 22. Therefore, it is possible to prevent the magnetic flux of the armature coil 14 from colliding with the proximal end portion of the salient pole 22 to increase the magnetic resistance and prevent the armature magnetic flux from becoming difficult to flow.

Further, in the rotary electric machine 1 according to the present embodiment, between adjacent salient poles 22, the vicinity of one salient pole 22 on the surface of the rotor 20 facing the stator 10 on the stator 10 side of the first bypass path BP1. A second bypass path BP2 that straddles the q-axis and extends toward the vicinity of the other salient pole 22 is provided.

Further, in the second bypass path BP2, the second permanent magnet PM2 is arranged so as to face the magnetic pole in the extending direction of the second bypass path BP2. Further, a third flux barrier FB3 is provided between the first bypass path BP1 and the second bypass path BP2.

As a result, since the rotor 20 is provided with the second permanent magnet PM2 in addition to the first permanent magnet PM1, the number of permanent magnets is increased, and the magnet torque can be increased when the rotary electric machine 1 is loaded.

Further, when the rotary electric machine 1 is not loaded, the magnetic flux of the second permanent magnet PM2 short-circuited in the rotor 20 is short-circuited in the short-circuit path of the first permanent magnet PM1 via the second bypass path BP2 and the salient pole 22. Therefore, it is possible to reduce the magnetic flux of the magnet interlinking with the stator 10 when there is no load.

Further, in the rotary electric machine 1 according to the present embodiment, the width of the third flux barrier FB3 in the vicinity of the stator 10 is Wb, the width of the third flux barrier FB3 in the vicinity of the q-axis is Wq, and the rotor 20 in the stator 10 is used. When the tooth spacing of the facing portion is Ws, Wb <Ws and Wb <Wq are satisfied.

By setting Wb <Ws in this way, it is possible to easily short-circuit the magnetic flux of the magnet in the rotor 20 when the rotary electric machine 1 is not loaded. Further, by setting Wb <Wq, it is possible to prevent a short circuit of the magnetic flux between the first bypass path BP1 and the second bypass path BP2, which does not contribute to torque, and improve the reluctance ratio when the rotary electric machine 1 is loaded. Therefore, the reluctance torque can be improved.

Further, in the rotary electric machine 1 according to the present embodiment, between adjacent salient poles 22, the vicinity of one salient pole 22 on the surface facing the stator 10 of the rotor 20 on the stator 10 side from the second bypass path BP2. A third bypass path BP3 that straddles the q-axis and extends toward the vicinity of the other salient pole 22 is provided. Further, a fourth flux barrier FB4 is provided between the second bypass path BP2 and the third bypass path BP3.

As a result, the magnet magnetic flux of the second permanent magnet PM2 can also be short-circuited from the third bypass path BP3, and the magnet magnetic flux of the second permanent magnet PM2 is short-circuited to the stator 10 side when the rotary electric machine 1 is not loaded. Can be prevented. Further, the reluctance torque can be increased by passing the armature magnetic flux through the third bypass path BP3 when the rotary electric machine 1 is loaded.

Further, in the rotary electric machine 1 according to the present embodiment, between adjacent salient poles 22, the vicinity of one salient pole 22 on the surface of the rotor 20 facing the stator 10 on the stator 10 side of the third bypass path BP3. A fourth bypass path BP4 that straddles the q-axis and extends toward the vicinity of the other salient pole 22 is provided.

Further, a fifth flux barrier FB5 is provided between the third bypass path BP3 and the fourth bypass path BP4. Further, a third permanent magnet PM3 is arranged on the fourth bypass path BP4 so as to face the magnetic pole in the extending direction of the fourth bypass path BP4, and the third permanent magnet PM3 is arranged so as to face each other with the q-axis interposed therebetween. A set of permanent magnets. Further, the fourth bypass path BP4 has a recess 25 recessed toward the rotor core 21 on the q-axis.

By providing the fourth bypass path BP4, the fifth flux barrier FB5, and the third permanent magnet PM3 in this way, the magnet torque can be increased when the rotary electric machine 1 is loaded. Further, the third permanent magnet PM3 is used as a set of permanent magnets arranged opposite to each other with the q-axis in between, and the fourth bypass path BP4 has a recess 25 on the q-axis which is recessed toward the rotor core 21 to obtain salient polarity. It can be improved and the reluctance torque can be increased.

Further, in the rotary electric machine 1 according to the present embodiment, a notch portion 24 forming a predetermined angle with respect to the tangent to the outer peripheral surface of the rotor 20 is formed at the end portion of the fourth bypass path BP4 on the stator 10 side. ..

As a result, the magnetic repulsive force of the third permanent magnet PM3 with respect to the armature magnetic flux can be applied in the tangential direction of the rotor 20, and the magnet torque can be increased.

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

In this embodiment, the present invention has been applied to an inner rotor type radial gap rotor, but the present invention can also be applied to an outer rotor type radial gap rotor and an axial gap rotor.

Further, in this embodiment, a plurality of permanent magnets arranged in each bypass path are arranged diagonally with respect to the q-axis, but the permanent magnets are arranged so that the magnetic poles of the permanent magnets are oriented in the direction perpendicular to the q-axis. Alternatively, the permanent magnets may be arranged in a cross pole shape.

In this embodiment, a rotary electric machine having 8 poles is illustrated, but the same magnetic circuit configuration can be adopted even in the case of a number of poles other than 8 poles such as 6 poles and 10 poles.

1 Rotating electric machine 10 Stator 11 Stator core 12 Stator teeth 14 Armature coil 20 Rotor 21 Rotor core 22 Pirate 24 Notch 25 Recess BP1 First bypass path BP2 Second bypass path BP3 Third bypass path BP4 Fourth bypass path FB1 First Flux barrier FB2 2nd flux barrier FB3 3rd flux barrier FB4 4th flux barrier FB5 5th flux barrier PM1 1st permanent magnet PM2 2nd permanent magnet PM3 3rd permanent magnet

Claims (8)

A rotary electric machine comprising a stator having an armature coil and a rotor core and a rotor having a plurality of salient poles provided on a surface of the rotor core facing the stator.
The rotor is
The first bypass path connecting the adjacent salient poles and the
A first permanent magnet arranged in the first bypass path at a position closest to the axis so as to face the magnetic pole in the extending direction of the first bypass path.
A rotary electric machine including a first flux barrier formed between the rotor core and the first bypass path. The rotary electric machine according to claim 1, wherein a second flux barrier is provided at the base end portion of the salient pole. A rotary electric machine comprising a stator having an armature coil and a rotor core and a rotor having a plurality of salient poles provided on a surface of the rotor core facing the stator.
The rotor is
The first bypass path connecting the adjacent salient poles and the
A first permanent magnet arranged in the first bypass path so as to face a magnetic pole in the extending direction of the first bypass path,
A first flux barrier formed between the rotor core and the first bypass path is provided.
A rotary electric machine characterized in that a second flux barrier is provided at the base end of the salient pole. Between the adjacent salient poles, on the stator side from the first bypass path, from the vicinity of one salient pole on the surface of the rotor facing the stator to the vicinity of the other salient pole across the q-axis. A second bypass path extending towards is provided,
A second permanent magnet is arranged in the second bypass path so as to face the magnetic pole in the extending direction of the second bypass path.
The rotary electric machine according to any one of claims 1 to 3, wherein a third flux barrier is provided between the first bypass path and the second bypass path. When the width of the third flux barrier in the vicinity of the stator is Wb, the width of the third flux barrier in the vicinity of the q-axis is Wq, and the tooth spacing of the portion of the stator facing the rotor is Ws.
The rotary electric machine according to claim 4, wherein Wb <Ws and Wb <Wq are satisfied. Between the adjacent salient poles, on the stator side from the second bypass path, from the vicinity of one salient pole on the surface of the rotor facing the stator to the vicinity of the other salient pole across the q-axis. A third bypass path extending towards is provided,
The rotary electric machine according to claim 4, wherein a fourth flux barrier is provided between the second bypass path and the third bypass path. Between the adjacent salient poles, on the stator side from the third bypass path, from the vicinity of one salient pole on the surface of the rotor facing the stator to the vicinity of the other salient pole across the q-axis. A fourth bypass path extending towards is provided,
A fifth flux barrier is provided between the third bypass path and the fourth bypass path.
A third permanent magnet is arranged in the fourth bypass path so as to face the magnetic pole in the extending direction of the fourth bypass path.
The third permanent magnet is a set of permanent magnets arranged opposite to each other across the q-axis.
The rotary electric machine according to claim 6, wherein the fourth bypass path has a recess on the q-axis that is recessed toward the rotor core. The rotary electric machine according to claim 7, wherein a notch portion forming a predetermined angle with respect to a tangent to the outer peripheral surface of the rotor is formed at an end portion of the fourth bypass path on the stator side. ..

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