WO2021106153A1

WO2021106153A1 - Rotary electric machine

Info

Publication number: WO2021106153A1
Application number: PCT/JP2019/046601
Authority: WO
Inventors: 勇気日高; 盛幸枦山; 宇宙満田
Original assignee: 三菱電機株式会社
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2021-06-03
Also published as: JPWO2021106153A1; JP6839376B1

Abstract

The purpose of the present invention is to provide a rotary electric machine capable of achieving both an improvement in torque/induced voltage ratio and a suppression of torque ripple. The rotary electric machine comprises: a stator (1); and a rotor (2) having a rotor core (21) in which a plurality of holes (22) are formed, a gap expanding portion (25) provided on the outer peripheral surface of the rotor core (21), and a plurality of magnet groups (23) that are a part of magnets arranged in the plurality of holes (22) and constitute a magnetic pole of one magnetic pole, the rotor being provided radially inside the stator (1) with a gap therebetween, wherein when the width perpendicular to the magnetic pole center line of the magnet on the magnetic pole center line, among the magnets constituting the magnet group (23), is defined as a magnet width Wmag, the width perpendicular to the magnetic pole center line of the gap expanding portion (25) is defined as a gap expanding portion width WA, and the width perpendicular to the magnetic pole center line of the rotor core (21) through which the axis line deviates by 90 degrees in the electric angle from the magnetic pole center line in the rotation direction or counter-rotation direction of the rotor (1) is the minimum width WB, the relationship, gap expanding portion width WA > magnet width Wmag > minimum width WB, is satisfied.

Description

Rotating machine

The present disclosure relates to a rotating electric machine equipped with an embedded magnet type rotor.

Patent Document 1 describes a magnet-embedded rotary electric machine. The rotor core of this magnet-embedded rotary electric machine has a plurality of magnetic pole regions in the circumferential direction, and each magnetic pole region has a flux barrier extending along the q-axis magnetic path. The inner wall of the flux barrier has a radial outer wall surface and a radial inner wall surface, and the radial inner wall surface extends from a position along the q-axis magnetic path toward an adjacent magnetic pole region.

International Publication No. 2016/147945

The above-mentioned magnet-embedded rotary electric machine can increase the reluctance torque by the configuration that suppresses the d-axis inductance and maintains the q-axis inductance, but the q-axis leakage magnetic flux of the magnet magnetic flux due to the d-axis inductance suppression increases. There is a problem that the torque ripple characteristic is lowered.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a rotary electric machine capable of achieving both improvement of torque / induced voltage ratio and suppression of torque ripple.

The rotary electric machine according to the present disclosure has a stator, a rotor core in which a plurality of holes are formed, and a gap expanding portion provided on an outer peripheral surface of the rotor core, and magnets arranged in the plurality of holes. Among the magnets constituting the magnet group, which are a part of the magnets and have a plurality of magnet groups constituting one magnetic pole, and a rotor provided inside the diameter of the stator through a gap. The width perpendicular to the magnetic pole center line of the magnet on the magnetic pole center line, which is the magnetic pole center line of one magnetic pole, is defined as the magnet width Wmag, and the width orthogonal to the magnetic pole center line of the gap expanding portion is defined as the gap expanding portion width WA. When the width perpendicular to the magnetic pole center line of the rotor core through which the axis, which is a line deviated by 90 degrees in the electric angle from the line to the rotation direction or counter-rotation direction of the rotor, is the minimum width WB, the gap expansion portion width WA> It satisfies the relationship of magnet width Wmag> minimum width WB.

According to the rotary electric machine of the present disclosure, it is possible to achieve both improvement of the torque / induced voltage ratio and suppression of torque ripple.

It is an external view of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is external drawing of the stator of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is external drawing of the rotor of the rotary electric machine which concerns on Embodiment 1 of this disclosure. FIG. 5 is an external view of a rotor excluding a shaft end component of a rotary electric machine according to a first embodiment of the present disclosure. It is a top view which shows the rotor of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is sectional drawing which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is a top view which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is a circuit diagram which shows the operation of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is a magnetic flux path diagram which showed the path of the magnetic flux which interlinks a rotary electric machine in Embodiment 1 of this disclosure. It is a graph which shows the torque / induced voltage ratio of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is a graph which shows the torque fluctuation width / average torque of the rotary electric machine in Embodiment 1 of this disclosure. It is a top view which shows the modification example of the rotor of the rotary electric machine which concerns on Embodiment 1 of this disclosure. It is a top view which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 2 of this disclosure. It is a magnetic flux path diagram which showed the path of the magnetic flux which interlinks a rotary electric machine in Embodiment 2 of this disclosure. It is a top view which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 3 of this disclosure. It is sectional drawing which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 4 of this disclosure. It is a top view which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 5 of this disclosure. It is a top view which shows the main part of the rotor of the rotary electric machine which concerns on Embodiment 6 of this disclosure. It is a magnetic flux path diagram which showed the path of the magnetic flux which interlinks the rotary electric machine which concerns on Embodiment 6 of this disclosure.

Embodiment 1.
The rotary electric machine according to the first embodiment of the present disclosure will be described.

FIG. 1 is an external view of the rotary electric machine according to the first embodiment of the present disclosure. FIG. 2 is an external view of a stator of a rotary electric machine according to the first embodiment of the present disclosure. FIG. 3 is an external view of a rotor of a rotary electric machine according to the first embodiment of the present disclosure. In this specification, the configurations necessary for the explanation are illustrated, and some configurations of the rear bracket, the front bracket, the bearing, and the like are omitted for convenience of explanation. The direction parallel to the axis of the rotation axis is the axial direction, and the axis of the rotation axis is the axis center. The direction orthogonal to the axis center of the rotating shaft is the radial direction, the outer side in the radial direction is the outer diameter direction or the outer diameter direction, and the inner side in the radial direction is the inner diameter direction or the inner diameter direction. The direction of rotation about the rotation axis is the circumferential direction or the rotation direction, and the direction opposite to the rotation direction is the counter-rotation direction.

The rotary electric machine 100 according to the first embodiment of the present disclosure is supported by a stator 1 fixed to the front and rear brackets and front and rear brackets via bearings, and is rotatably arranged inside the diameter of the stator 1. It has a rotor 2 that has been bearing. It also has a shaft 3 that is inserted at the axial position of the rotor 2. The stator 1 is provided so as to surround the outer periphery of the rotor 2 via a gap G that serves as a magnetic gap.

As shown in FIG. 2, the stator 1 has a stator core 11 having a plurality of magnetic pole teeth 13 and a stator winding 12 wound around the stator core 11.
As the rotor 2 rotates, the stator winding 12 receives a magnetic flux from a magnet 231 provided on the rotor 2, which will be described later, and generates an induced voltage.

As shown in FIG. 3, the rotor 2 has a cylindrical rotor core 21 having a shaft insertion hole for arranging the shaft 3 at the axial center position. The shaft 3 arranged in the shaft insertion hole and the rotor core 21 are fixed to each other. The rotor core 21 is configured by, for example, laminating and integrating thin plates of electrical steel sheets in the axial direction.

The rotor 2 according to the first embodiment of the present disclosure will be further described with reference to FIGS. 4 to 6.
FIG. 4 is an external view of a rotor of a rotary electric machine according to the first embodiment of the present disclosure. For convenience of explanation, the shaft 3 and the shaft end parts are omitted. FIG. 5 is a plan view of the rotary electric machine according to the first embodiment of the present disclosure when viewed from the axial direction. FIG. 6 is a cross-sectional view of a main part of the rotor of the rotary electric machine according to the first embodiment of the present disclosure. FIG. 7 is a plan view of a main part of the rotary electric machine according to the first embodiment of the present disclosure when viewed from the axial direction. In order to prevent each drawing from becoming complicated, the reference numerals of some of the illustrated configurations are omitted.

As shown in FIG. 4, the rotor core 21 of the rotor 2 has a plurality of holes 22 extending in the axial direction of the rotor core 21, slits 24, and an enlarged gap provided on the outer peripheral surface of the rotor core 21. A portion 25 and a portion 25 are formed, and a magnet 231 is embedded in each of the plurality of hole portions 22. The plurality of holes 22 penetrate in the axial direction of the rotor core 21. Further, each hole portion 22 is provided in the rotor core 21 in the circumferential direction in accordance with the arrangement position of the magnet 231 described later.

As shown in FIG. 5, each magnet 231 is formed in a rectangular shape. Each magnet 231 is magnetized in the direction from one long side of the rectangle to the other long side, that is, parallel to the short side. Specifically, as shown by the arrow in FIG. 5, in the N-pole magnetic pole forming a path in which the magnetic flux of the magnet is interlinked with the stator 1, the magnetic flux of the magnet 231 is magnetized so as to be directed toward the stator 1. And placed. Further, in the S pole magnetic pole forming a path from the stator 1 to the rotor 2, the magnetic flux of the magnet 231 is magnetized and arranged so as to be inside the diameter of the rotor 2. By magnetizing and arranging in this way, the magnetic flux formed by each magnet 231 and interlinking with the stator 1 can be effectively increased. This makes it possible to form the magnet amount of the magnet 231 arranged on the rotor 2 required to realize the desired output of the rotary electric machine 100 with the minimum amount.

As shown in FIG. 6, each of the holes 22 is composed of a magnet insertion portion 221 in which the magnet 231 is embedded and an opening 222 in which the magnet 231 is not embedded. The magnet insertion portion 221 is formed so as to border the shape of the magnet 231 to be embedded. The openings 222 other than the magnet insertion portion 221 are formed at both ends of the magnet insertion portion 221 in the longitudinal direction. Further, the opening 222 is hollow.

Further, a magnet group 23 arranged so as to form one magnetic pole is configured by some magnets 231 of the plurality of magnets 231. A plurality of the magnet groups 23 are arranged adjacent to each other in the circumferential direction of the rotor core 21. The magnet group 23 constituting one magnetic pole is composed of three magnets 231 and arranged so that the three magnets 231 form an arc shape having a bulge toward the center of the axis from the outer peripheral surface side of the rotor 2. One of the magnets 231 constituting the magnet group 23 is located on the center of the magnetic pole, which is the center of the magnetic pole formed by the magnet group 23. That is, when the line from the axis center of the rotor core 21 through the magnetic pole center formed by the magnet group 23 is defined as the magnetic pole center line (hereinafter, also referred to as d-axis), the magnetic pole center line (d-axis) is straddled in the circumferential direction. Be placed. Of the magnets 231 constituting the magnet group 23, the magnet 231 located on the d-axis is referred to as the magnet 232 for convenience of explanation.

As shown in FIG. 6, the slit 24 is surrounded by the magnet group 23 constituting one magnetic pole, which is outside the diameter of the rotor 2 with respect to the magnet 232 located on the center of the magnetic pole among the magnet group 23 constituting one magnetic pole. It is provided on the rotor core 21 within the circumferential range. The slit 24 is formed in an arc shape having a bulge in the same direction as the arc shape formed by the magnet group 23. That is, both ends of the slit 24 in the circumferential direction are formed on the rotor core 21 whose diameter is outside the central portion of the slit.

The slit 24 penetrates the rotor core 21 in the axial direction and is hollow. Further, it is formed so as to straddle the above-mentioned magnetic pole center line in the circumferential direction. By providing the slit 24 in this way, the magnetic resistance of the magnetic flux path through the d-axis can be increased regardless of the distance of the gap G between the stator 1 and the rotor 2. That is, it is possible to achieve both the effect of increasing the d-axis magnetic resistance while maintaining the surface area of the outer peripheral surface which is the magnetic flux output surface of the rotor 2.

The gap expanding portion 25 is provided on the outer peripheral surface of the rotor core 21 surrounded by the slit 24 and the gap G. The gap expanding portion 25 is provided in an arc shape recessed from the outer peripheral surface of the rotor core 21 toward the center of the shaft. As a result, the range of the gap is expanded from each of the two intersections on the outer peripheral surface of the rotor core 21 on which the gap expanding portion 25 is formed toward the axial center of the rotor 2. Further, the circumferential range of the gap expanding portion 25 is formed to be smaller than the circumferential width of the slit 24.

The relationship between the hole portion 22, the slit 24, the void enlargement portion 25, and the magnet 231 of the rotor core 21 will be described with reference to FIG. 7.

As shown in FIG. 7, the length in the rotation direction connecting the two intersections of the gap expanding portion 25 and the outermost circumference of the rotor core 21 so as to be orthogonal to the d-axis is defined as the gap expanding portion width WA. Further, among the magnet group 23 forming one magnetic pole, the length of the line connecting both end points of the magnet 232 located on the magnetic pole center line in the rotational direction so as to be orthogonal to the d-axis is defined as the magnet width Wmag. Then, a line deviated from the magnetic pole center line (d-axis) by 90 degrees in the electric angle in the rotation direction or the counter-rotation direction is defined as the axis (q-axis).

At this time, the q-axis passes through the rotor core 21 between the adjacent magnet groups 23. The width of the rotor core 21 in the orthogonal plane where the rotor core 21 and the q-axis located between the adjacent magnet groups 23 are orthogonal to each other is the hole closest to the q-axis of one of the adjacent magnet groups 23. It is the smallest in the rotor core 21 between 22 and the hole 22 closest to the q-axis of the other adjacent magnet group 23. The width of the smallest rotor core 21 is defined as the minimum width WB.

The rotary electric machine 100 according to the first embodiment of the present disclosure satisfies WA> Wmag in the relationship between the gap expanding portion width WA of the gap expanding portion 25 and the magnet width Wmag of the magnet 232. Further, Wmag> WB is satisfied in the minimum width WB and the magnet width Wmag of the magnet 232. Then, the relationship of WA> Wmag> WB is satisfied in the relationship between the gap expanding portion width WA, the magnet width Wmag, and the minimum width WB.

Next, the operation of the rotary electric machine 100 according to the first embodiment of the present disclosure will be described. FIG. 8 illustrates the operation of the rotary electric machine 100 as an electric motor of the AC generator motor for vehicles. It has a power circuit unit 4, a control circuit unit 5, and a battery 6 as a configuration other than the rotary electric machine 100 for operating as an electric motor of an AC generator motor for vehicles.

The power circuit unit 4 has a switching element. This switching element is ON / OFF controlled by the control circuit unit 5. Then, the power circuit unit 4 converts the DC power supplied from the battery 6 into AC power by ON / OFF control of the switching element and supplies it to the rotary electric machine 100.

The control circuit unit 5 has a processor 51 and a storage unit 52. The processor 51 performs the above-mentioned processing by executing the program stored in the storage unit 52. Here, the storage unit 52 is composed of a memory in which parameters necessary for control, a program describing the above processing, and the like are stored. The processor is composed of a microcomputer (microcomputer), a DSP (Digital Signal Processor), an FPGA, and the like. Further, the plurality of processors 51 and the plurality of storage units 52 may cooperate to execute the above function.
Since the power circuit unit 4, the control circuit unit 5, and the battery 6 are well-known techniques, other detailed description of each configuration will be omitted.

Specifically, the AC power supplied to the rotary electric machine 100 is supplied to the stator winding 12 of the stator 1. The driving torque is generated by the magnetic flux generated at this time and the magnetic flux formed by the magnet 232 interlinking with the direct current or alternating current flowing through the stator winding 12. The rotor 2 is rotationally driven by this drive torque.

FIG. 9 is a magnetic flux path diagram showing the path of the magnetic flux interlinking the rotary electric machine 100 in the first embodiment of the present disclosure. The solid line shown in FIG. 9 schematically shows the path of the magnetic flux generated from the magnet group 23 through the stator 1. As described above, the magnetic flux interlinking the stator winding 12 of the stator 1 contributes to the drive torque. Therefore, the magnetic flux passing through the path shown by the solid line is the output contributing magnetic flux that contributes to the output. Further, the alternate long and short dash line shown in FIG. 9 schematically shows the path of the magnetic flux that closes in the rotor core 21 without passing through the stator winding 12 of the stator 1. The magnetic flux passing through the path indicated by the alternate long and short dash line is a leakage magnetic flux that does not contribute to the output because the stator winding 12 of the stator 1 is not interlocked.

The output contributing magnetic flux is mainly contributed by the magnetic flux created by the magnet 232 arranged on the d-axis line. That is, the drive torque can be increased by increasing the magnetic flux of the magnet 232 on the d-axis line. On the other hand, as the magnetic flux of each

magnet

231 and 232 increases, the induced voltage increases. When the induced voltage increases, the induced voltage of the rotary electric machine 100 exceeds the voltage of the battery 6 shown in FIG. When the induced voltage of the rotary electric machine 100 exceeds the voltage of the battery 6, the regenerative mode in which power is supplied from the rotary electric machine 100 to the battery 6 side is entered. In principle, the drive torque cannot be obtained unless the voltage of the rotary electric machine 100 is lower than the voltage of the battery 6. For example, if a current that suppresses the induced voltage of the rotary electric machine 100 is supplied by ON / ОFF control of the switching element of the power circuit unit 4, the induced voltage of the rotary electric machine 100 can be made lower than the voltage of the battery 6. It is also possible to obtain the drive torque. However, since the current for suppressing the induced voltage is not the current for obtaining torque, the current required for obtaining the desired torque increases, and the loss increases. As a result, the output of the rotary electric machine 100 decreases. From these facts, it is desirable to reduce the induced voltage, and in order to reduce the induced voltage, it is desirable to reduce the magnetic flux induced in the stator winding 12 of the stator 1.

Leakage magnetic flux contributes to torque ripple by increasing. Torque ripple is expressed as torque fluctuation range / average torque. Therefore, it is possible to suppress the torque ripple by reducing the leakage magnetic flux shown in FIG.

In the first embodiment of the present disclosure, the gap expanding portion 25 is provided so as to cover the circumferential direction on the outer diameter of the magnet 231 arranged on the d-axis line. That is, the gap expanding portion 25 is provided on the path of the magnet magnetic flux created by the magnet 232 arranged on the d-axis line. As a result, the magnetic resistance of the rotor core 21 in the range where the void expansion portion 25 is formed increases. Therefore, the effect of reducing the induced voltage induced in the stator winding 12 of the stator 1 can be obtained. Further, by providing the gap expanding portion 25 and increasing the d-axis magnetic resistance, the q-axis magnetic resistance with respect to the d-axis magnetic resistance becomes relatively lower than when the gap expanding portion 25 is not provided. Therefore, it is possible to increase the reluctance torque obtained by the difference in the magnetic resistance between the d-axis and the q-axis.

FIG. 10 is a graph showing the effect of improving the torque / induced voltage ratio of the rotary electric machine 100 in the first embodiment of the present disclosure. One of the graphs shown in FIG. 9 is a case where WA> Wmag is configured between the gap expanding portion width WA of the gap expanding portion 25 and the magnet width Wmag of the magnet 232 on the d-axis. It is the result of the torque / induced voltage ratio. The other is the result of the torque / induced voltage ratio when the relationship of WA <Wmag is established between the gap expanding portion width WA and the magnet width Wmag of the magnet 232 on the d-axis. As shown in FIG. 10, the torque / induced voltage ratio can be improved by configuring WA> Wmag in relation to the gap expanding portion width WA and the magnet width Wmag of the rotor magnet on the d-axis. ..

In the first embodiment of the present disclosure, the minimum width WB is smaller than the magnet width Wmag of the magnet 232 on the d-axis. As the path surface of the leakage magnetic flux path of the rotor core 21 on the q-axis side with respect to the magnetic flux output surface of the magnet 231 becomes smaller, the magnetic resistance of the rotor core 21 on the leakage magnetic flux path increases. Therefore, the leakage magnetic flux can be reduced.

FIG. 11 is a graph showing the effect of suppressing the torque ripple of the torque fluctuation width / average torque of the rotary electric machine 100 in the first embodiment of the present disclosure. One of the graphs shown in FIG. 11 is the result of the torque fluctuation width / average torque when Wmag> WB is satisfied in the relationship between the minimum width WB and the magnet width Wmag of the magnet 232 on the d-axis. The other is the result of the torque fluctuation width / average torque when Wmag <WB in the relationship between the minimum width WB and the magnet width Wmag of the magnet 232 on the d-axis. As shown in FIG. 11, in the relationship between the minimum width WB and the magnet width Wmag of the magnet 232 on the d-axis, the torque fluctuation width / average torque, that is, the torque ripple is suppressed by configuring so that Wmag> WB is satisfied. be able to.

In the first embodiment of the present disclosure, as described above, in the relationship between the gap expanding portion width WA of the gap expanding portion 25, the magnet width Wmag of the magnet 232 arranged on the d-axis, and the minimum width WB, WA> Wmag> Meet the WB. That is, the magnet width of the magnet 232 is smaller than the width of the void expansion portion, and the minimum width WB of the rotor core 21 on the leakage magnetic flux path of the magnet 232 is the minimum width WB of the magnet 232 arranged on the d-axis line. Is configured to be smaller than. As a result, in addition to the effect of improving the torque / induced voltage ratio, the torque ripple suppression function can be obtained, and both the torque / induced voltage ratio improvement and the torque ripple suppression can be achieved at the same time.

Further, the magnet group 23 is arranged in an arc shape intermittently by a plurality of

magnets

231 and 232. As a result, the rotor core 21 is present between the

magnets

231 and 232 forming the arc shape. Specifically, a rotor core 21 that connects the outer diameter and the inner diameter of the magnet group 23 exists between the

magnets

231 and 232. As a result, the maximum principal stress applied to the rotor core 21 passing through the q-axis between the adjacent magnet groups 23 can be reduced.

Although the magnet group 23 has been described with reference to an example in which the magnet group 23 is composed of three magnets in the first embodiment of the present disclosure, the number of magnets 231 constituting the magnet group 23 is not limited to three. The magnets 231 constituting the magnet group 23 may be arranged in an arc shape along the magnetic flux created by the stator winding 12. For example, as shown in FIG. 12, the stator winding 12 has five magnets 231. It may be arranged in an arc along the magnetic flux to be created. Further, although the shape of each magnet 231 is rectangular, the shape is not limited to a rectangle, and the magnets 231 may be formed in an arc shape and arranged along the magnetic flux generated by the stator winding 12. Further, the magnetizing method does not need to be magnetized parallel to the short side.

Further, the opening 222 and the slit 24 do not necessarily have to be hollow, and for example, a non-magnetic material such as resin may be embedded. Further, the hole portion 22 may be configured not to have the opening portion 222.

In addition, an example of operating as an electric motor for an AC generator motor for vehicles has been shown, but the application is not limited to this and can be applied as long as it operates as a rotary electric machine.

In either case, the same effect as described above can be obtained.

Embodiment 2.
The rotary electric machine according to the second embodiment of the present disclosure will be described. Those having the same reference numerals as those in FIGS. 1 to 12 indicate the same or corresponding configurations, and the description thereof will be omitted. Only the part different from the first embodiment will be described. FIG. 13 is an axial plan view showing a main part of the rotor of the rotary electric machine according to the second embodiment of the present disclosure. FIG. 14 is a magnetic flux path diagram showing the path of the magnetic flux interlinking the rotary electric machine according to the second embodiment of the present disclosure.

In the first embodiment of the present disclosure, the minimum width WB is the other of the orthogonal surfaces of the rotor core 21 orthogonal to the q-axis, which is adjacent to the hole 22 closest to the q-axis of one of the adjacent magnet groups 23. It was explained that it is the width of the rotor core 21 between the magnet group 23 and the hole 22 closest to the q-axis. In the second embodiment of the present disclosure, this minimum width WB is the width of the rotor core 21 between the end points of one adjacent hole 22 and the other 22 end points.

I will explain more specifically. As described above, the hole portion 22 is composed of a magnet insertion portion 221 in which the magnet 231 is embedded and an opening 222 in which the magnet 231 is not embedded. Further, the magnet insertion portion 221 is formed so as to border the shape of the magnet 231 to be embedded. In the second embodiment of the present disclosure, the rotor core 21 between the end point of the magnet insertion portion 221 formed so as to border the magnet 231 and the end point of the adjacent magnet insertion portion 221 has a minimum width WB. .. In other words, the minimum width WB is between the end points of the magnet insertion portions 221 of the magnet group 23 closest to the q-axis passing between the adjacent magnet groups 23.

As described above, the rotor core 21 passing through the q-axis serves as a path of leakage magnetic flux that closes in the rotor core 21 without passing through the stator winding 12 of the stator 1. This leakage magnetic flux includes the leakage magnetic flux from the magnet 232 located on the d-axis constituting the magnet group 23 as shown by the alternate long and short dash line in FIG. 9, and separately, as shown by the alternate long and short dash line in FIG. The magnetic flux leakage from the magnet 231 arranged on the q-axis side of the magnet group 23 is also included. The path of the magnetic flux leakage of the magnet 231 arranged on the q-axis side passes through the inside of the arc formed by the magnet group 23, and goes to the same magnet 231 via the rotor core 21 through which the q-axis passes without passing through the stator 1. It will be a return route. At this time, the inflow surface when the leakage magnetic flux returns to the magnet 231 is the rotor core 21 between the end point of the magnet insertion portion 221 and the end point of the adjacent magnet insertion portion 221.

In this way, the minimum width WB is set between the end points of the magnet insertion portions 221 of the magnet group 23 closest to the q-axis passing between the adjacent magnet groups 23, so that the minimum width WB is obtained from the

magnets

231 and 232. The magnetic resistance of the rotor core 21 in the leakage magnetic flux path through which the leakage magnetic flux passes can be increased. Further, in particular, it is possible to maximize the reluctance at the inflow surface to the magnet 231 in the path of the magnetic flux leakage in which the magnetic flux generated from the magnet 231 arranged on the q-axis side returns to the same magnet 231 without passing through the stator 1. it can.

This makes it possible to further suppress the magnetic flux leakage to the rotor core 21 passing through the q-axis, and has the effect of suppressing torque ripple. Further, the magnet insertion portion 221 also has a function of holding the position of the magnet 231 to be embedded. Therefore, in addition to the same effect as that of the first embodiment of the present disclosure, the effect of being able to further reduce the torque ripple while maintaining the position of the magnet 231 is also obtained.

Embodiment 3.
The rotary electric machine according to the third embodiment of the present disclosure will be described. Those having the same reference numerals as those in FIGS. 1 to 14 indicate the same or corresponding configurations, and the description thereof will be omitted. Only the parts different from the first embodiment and the second embodiment will be described. FIG. 15 is an axial plan view showing a main part of the rotor of the AC rotary electric machine according to the third embodiment of the present disclosure.

As shown in FIG. 15, among the end points of the magnet insertion portions 221 of the adjacent holes 22 via the rotor core 21 through which the q-axis passes, the end points inside the diameter of the rotor core 21 are orthogonal to the q-axis. The width tied to is the maximum width WC.

At this time, in relation to the magnet width Wmag of the magnet 232 on the d-axis, the magnet width Wmag> the maximum width WC is satisfied. That is, the entire width of the path of the leakage magnetic flux on the q-axis side generated by the magnetic flux of the magnet 231 is smaller than the magnet width Wmag of the magnet 231 on the d-axis line. As a result, the magnetic resistance of the rotor core 21 passing through the q-axis, which is the path of the leakage magnetic flux, can be increased.

Therefore, in addition to the same effects as those of the first and second embodiments of the present disclosure, the torque ripple can be further suppressed by further enhancing the function of reducing the leakage magnetic flux.

Embodiment 4.
The rotary electric machine according to the fourth embodiment of the present disclosure will be described. Those having the same reference numerals as those in FIGS. 1 to 15 indicate the same or corresponding configurations, and the description thereof will be omitted. Only the parts different from the first to third embodiments will be described. FIG. 16 is a plan view of a main part of the rotor of the rotary electric machine according to the fourth embodiment of the present disclosure.

As shown in FIG. 16, in the magnetic pole tooth 13 protruding from the stator 1 to the rotor 2 side, the magnetic pole tooth width of the surface (innermost diameter inner surface) located on the innermost diameter side in the radial direction and facing the gap G is WT. And. Specifically, it is the width when both ends of one magnetic pole tooth 13 in the rotation direction are connected so as to be orthogonal to the q-axis.

At this time, WT> WB is satisfied in relation to the minimum width WB. That is, in the path of the magnetic flux flowing from the magnetic pole tooth width of the magnetic pole tooth 13 to the rotor core 21 passing through the q-axis, the width of the surface of the rotor core 21 into which the magnetic flux flows is smaller.

As described above, the leakage magnetic flux illustrated and described in FIG. 14 does not contribute to the drive torque because it does not pass through the magnetic pole teeth 13 of the stator 1. Therefore, it is preferable that the magnetic flux passing through the path on the q-axis side without passing through the magnetic pole teeth 13 is small.

In the fourth embodiment of the present disclosure, by satisfying WT> WB in the relationship between the magnetic pole tooth width WT and the minimum width WB of the magnetic pole tooth 13, the rotation in which the leakage magnetic flux flows into the magnetic flux output surface of the magnet 231. The width of the surface of the child core 21 can be reduced. As a result, the magnetic resistance of the rotor core 21 on the leakage magnetic flux path can be increased, and in particular, the rotor core 21 can be moved from the magnet 231 other than the magnet 232 located on the d-axis to the rotor core 21 without the magnetic pole teeth 13 of the stator 1. The leakage magnetic flux can be reduced.

Therefore, in addition to the same effects as those of the first to third embodiments of the present disclosure, the leakage magnetic flux of the magnet 231 not arranged on the d-axis can be reduced, and the torque ripple can be further suppressed. It has the effect of

Embodiment 5.
The rotary electric machine according to the fifth embodiment of the present disclosure will be described. Those having the same reference numerals as those in FIGS. 1 to 16 indicate the same or corresponding configurations, and the description thereof will be omitted. Only the parts different from the first to fourth embodiments of the present disclosure will be described. FIG. 17 is a plan view of a main part of the rotor of the rotary electric machine according to the fifth embodiment of the present disclosure.

As shown in FIG. 17, the gap expanding portion 25 is provided line-symmetrically with respect to the d-axis. Further, the magnet 231 located on the d-axis of the magnet group 23 is also provided line-symmetrically with respect to the d-axis. That is, the center line of the gap expanding portion 25 and the center line of the magnet 232 located on the d-axis are on the same line. The center line of the gap expanding portion 25 is a line bisected by perpendicular to a line connecting both ends of the gap expanding portion 25 in the rotation direction so as to be orthogonal to the q-axis. The center line of the magnet 231 located on the d-axis is a line bisected by perpendicular to a line connecting both ends of the magnet 231 located on the d-axis in the rotational direction so as to be orthogonal to the q-axis.

As a result, the gap expanding portion 25 can more effectively suppress the magnetic flux generated by the magnet 231 located on the d-axis. Therefore, in addition to the same effects as those of the first to fourth embodiments of the present disclosure, the torque / induced voltage ratio can be further improved.

The line that bisects the void expansion portion 25 in the rotation direction (first bisector) and the magnet 231 located on the d-axis are bisected in the rotation direction (second bisector line). ) Are the same, and the gap expanding portion 25 and the magnet 231 located on the d-axis do not necessarily have to be provided line-symmetrically on the d-axis. Further, each center line does not have to coincide with the d-axis. Even in this case, the effect of improving the torque / induced voltage ratio is achieved.

Embodiment 6.
The rotary electric machine according to the sixth embodiment of the present disclosure will be described. Those having the same reference numerals as those in FIGS. 1 to 17 indicate the same or corresponding configurations, and the description thereof will be omitted. Only the parts different from the first to fifth embodiments of the present disclosure will be described. FIG. 18 is an axial plan view showing a main part of the rotor of the rotary electric machine according to the fifth embodiment of the present disclosure. FIG. 19 is a magnetic flux path diagram showing the path of the magnetic flux interlinking the rotary electric machine according to the sixth embodiment of the present disclosure.

As shown in FIG. 18, the magnet length of half of the magnet 231 obtained by dividing the length of the magnet 231 on the d-axis in the rotation direction by the d-axis is defined as Wmagk. At this time, Wmagk> WB is satisfied in relation to the minimum width WB.

The dotted line in FIG. 19 shows the path of the magnetic flux created by the magnet 231 located on the d-axis.
Half of the magnetic flux generated by the magnet 231 located on the d-axis creates a magnetic flux leakage path in the rotor core 21 passing through the q-axis on the rotation direction side, and the other half creates a leakage magnetic flux in the rotor core 21 on the opposite rotation direction side. Form the path of.

In the sixth embodiment of the present disclosure, the minimum width WB of the rotor core 21 on the leakage magnetic flux path is smaller than the length Wmagk divided by the d-axis of the magnet 231 located on the d-axis, so that it is on the q-axis side. The magnetic resistance can be increased. Therefore, the magnetic flux leakage to the q-axis side can be further reduced.

Therefore, in addition to the same effects as those of the first to fifth embodiments of the present disclosure, the torque ripple can be further suppressed.

Although the magnet lengths divided by the d-axis have been described by showing an example of being the same, they do not necessarily have to be the same and may be larger than the corresponding minimum width WB. Further, the magnet 231 on the d-axis does not necessarily have to be provided so as to be orthogonal to the d-axis. In that case, Wmagk is defined as the magnet length by the length connecting the ends of the magnets 231 in the rotation direction so as to be orthogonal to the d-axis, and if Wmagk> WB is satisfied in relation to the minimum width WB. Good. The same effect can be obtained in this case as well.

Each embodiment can be freely combined, and each embodiment can be appropriately modified or omitted.

1 stator, 2 rotor, 3 shaft, 4 power circuit, 5 control circuit, 6 battery, 11 stator core, 12 stator winding, 13 magnetic pole teeth, 21 rotor core, 22 holes, 23 magnets Group, 24 slits, 25 void enlargement part, 100 rotary electric machine, 221 magnet insertion part, 222 opening part, 231 and 232 magnets

Claims

Stator and
It has a rotor core in which a plurality of holes are formed, a gap expanding portion provided on the outer peripheral surface of the rotor core, and is a part of magnets arranged in the plurality of holes and has one magnetic pole. A rotor having a plurality of magnet groups constituting the magnetic poles of the above and provided inside the diameter of the stator through a gap, and
With
Among the magnets constituting the magnet group, the width perpendicular to the magnetic pole center line of the magnet on the magnetic pole center line, which is the magnetic pole center line of one magnetic pole, is defined as the magnet width Wmag.
The width of the gap expanding portion perpendicular to the magnetic pole center line is defined as the gap expanding portion width WA.
When the width perpendicular to the magnetic pole center line of the rotor core passing through the axis, which is a line deviated by 90 degrees in the electric angle from the magnetic pole center line in the rotation direction or the counter-rotation direction of the rotor, is defined as the minimum width WB.
A rotary electric machine that satisfies the relationship of void expansion portion width WA> magnet width Wmag> minimum width WB.
The minimum width WB is the width of the rotor core between one of the holes adjacent via the axis and the other hole adjacent via the axis, according to claim 1. Rotating electric machine.
The hole portion has a magnet insertion portion in which the magnet is arranged and an opening other than the magnet insertion portion.
The minimum width WB is the width of the rotor core between one magnet insertion portion adjacent via the axis and the other magnet insertion portion adjacent via the axis. The rotary electric machine described in.
The minimum width WB includes an end point closest to the axis of one of the magnet insertion portions adjacent via the axis, and an end point closest to the axis of the other magnet insertion portion adjacent via the axis. The rotary electric machine according to claim 3, which is the width of the rotor core between the two.
Of the end points of one of the magnet insertion portions adjacent via the axis, the end points inside the diameter of the rotor core and the end points of the other magnet insertion portion adjacent via the axis, the rotor core When the width of the rotor core between the end points on the inner diameter of the rotor core is the maximum width WC,
The rotary electric machine according to claim 3 or 4, which satisfies the relationship of magnet width Wmag> maximum width WC.
When the line that bisects the gap expansion portion in the rotation direction is defined as the first bisector, and the line that bisects the magnet on the magnetic pole center line in the rotation direction is defined as the second bisector. ,
The rotary electric machine according to any one of claims 1 to 5, wherein the first bisector and the second bisector are on the same line.
The rotary electric machine according to any one of claims 1 to 6, wherein the minimum width WB of the rotor core is smaller than half the width of the magnet width Wmag.
The stator has magnetic pole teeth protruding toward the rotor side.
When the width of the innermost diameter inner surface of the magnetic pole tooth is defined as the magnetic pole tooth width WT,
The rotary electric machine according to any one of claims 1 to 7, which satisfies the relationship of magnetic pole tooth width WT> minimum width WB.