Rotating electric machines, rotating electric machine units, and electric vehicles

Abstract

A rotary electric machine (1) is provided with: a rotor (20) that has, for each pole, a first permanent magnet (22A) and a second permanent magnet (22B); and a stator (30) that has a stator core (31) and a winding (32) and is arranged relative to the rotor (20) with a gap therebetween. The first permanent magnets (22A) are disposed at positions advanced in the forward rotation direction of the rotor (20) with respect to a d-axis (d0) of the rotor (20), and the second permanent magnets (22B) are disposed at delayed positions. On the basis of the difference in heat generation level between the first permanent magnets (22A) and the second permanent magnets (22B) that generate heat in accordance with the operation of the rotary electric machine (1), one group of the magnets among the first and second permanent magnets (22A, 22B) is taken as high-heat-generation magnets, and the other as low-heat-generation magnets, and the rotor (20) is cooled by heat transfer through a fluid (50) by making the heat dissipation from the high-heat-generation magnets larger than the heat dissipation from the low-heat-generation magnet.

Description

Technical Field

[0001] This application relates to a rotating electric machine, a rotating electric machine unit, and an electric vehicle.

Background Art

[0002] Rotating electric machines for electric vehicles are required to be small and have high output. It is effective to improve the uniformity of the temperature distribution within the rotating electric machine and reduce the maximum temperature. In addition, for the purpose of increasing torque, a permanent magnet synchronous motor (PMSM) having permanent magnets on the rotor is often used for rotating electric machines for electric vehicles.

[0003] In the rotating electric machine according to the prior art described in Patent Document 1, in a coil in which coil strands are wound around a stator core, the heat generation amount of the coil strands at a portion where heat dissipation is easy in the heat dissipation path from the coil is increased, and the heat generation amount of the coil strands at a portion where heat dissipation is difficult in the heat dissipation path from the coil is decreased. Thereby, the temperature distribution difference inside the coil can be reduced, and the maximum temperature of the coil can be reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the prior art described in Patent Document 1 above, the temperature distribution inside the coil is adjusted by the size of the cross-sectional area of the coil strands, and the uniformity of the temperature distribution of the rotor having permanent magnets cannot be improved.

[0006] This invention discloses technology to solve the above-mentioned problems, and aims to improve the uniformity of the temperature distribution within a rotating electric machine having a permanent magnet in the rotor, thereby reducing the maximum temperature and enabling miniaturization and high output. Furthermore, it aims to provide a rotating electric machine unit and an electric vehicle equipped with such a rotating electric machine. [Means for solving the problem]

[0007] The rotating electric machine disclosed herein comprises a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor. A rotating electric machine for an electric vehicle, wherein the forward rotation of the rotor is the primary direction of rotation, and is the direction of rotation when the electric vehicle moves forward. The first permanent magnet is positioned advanced in the forward rotation direction of the rotor relative to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the d-axis of the rotor in the forward rotation direction of the rotor. Based on the difference in the heat generation levels of the first and second permanent magnets, which are generated in response to the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. Furthermore, the rotating electric machine disclosed herein comprises a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and arranged with an air gap between it and the rotor, wherein the first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor, and based on the difference in the heat generation levels of the first permanent magnet and the second permanent magnet which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The fluid flows axially to cool the rotor, and the rotor comprises a first block with a first permanent magnet for each pole and a second block with a second permanent magnet for each pole, arranged axially, with the first and second blocks having the high-heat-generating magnets positioned upstream of the fluid and the block having the low-heat-generating magnets positioned downstream of the fluid. Furthermore, the rotating electric machine disclosed herein comprises a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and arranged with an air gap between it and the rotor, wherein the first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor, and based on the difference in the heat generation levels of the first permanent magnet and the second permanent magnet which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The rotor is provided with through holes that penetrate axially through each pole, and the fluid flows through these through holes to cool the rotor. The through holes are positioned such that the distance from the through hole to the high-heat magnet is shorter than the distance from the through hole to the low-heat magnet. Furthermore, the rotating electric machine disclosed herein comprises a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and arranged with an air gap between it and the rotor, wherein the first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor, and based on the difference in the heat generation levels of the first permanent magnet and the second permanent magnet which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The rotor is provided with a first permanent magnet and a second permanent magnet arranged symmetrically with respect to the d-axis for each pole, and further includes a first through-hole and a second through-hole that penetrate in the axial direction for each pole, the fluid flows through the first and second through-holes in the same direction to cool the rotor, the first through-hole is located on the side of the d-axis where the first permanent magnet is located, and the second through-hole is located on the side of the d-axis where the second permanent magnet is located, the first and second through-holes are arranged symmetrically with respect to the d-axis, and the velocity of the fluid flowing through the through-hole on the side where the high-heat-generating magnet is located is greater than the velocity of the fluid flowing through the through-hole on the side where the low-heat-generating magnet is located.

[0008] Furthermore, the rotating electric machine unit disclosed in this application comprises a rotating electric machine and an inverter for driving and controlling the rotating electric machine, the rotor comprises a first block having the first permanent magnet for each pole and a second block having the second permanent magnet for each pole arranged in the axial direction, and the inverter is disposed on one shaft end side of the rotating electric machine, on the side of the first and second blocks that is closer to the block having the low-heat generating magnet.

[0009] Furthermore, the rotating electric machine unit disclosed in this application comprises a rotating electric machine and a reduction gear connected to the rotating electric machine, the rotor comprises a first block having the first permanent magnet for each pole and a second block having the second permanent magnet for each pole arranged in the axial direction, and the reduction gear is disposed on one shaft end side of the rotating electric machine, on the side of the first and second blocks that is closer to the block having the low-heat generating magnet.

[0010] Furthermore, the electric vehicle disclosed herein is driven by the aforementioned rotating electric machine. It is. [Effects of the Invention]

[0011] The rotating electric machine disclosed in this application is a rotating electric machine having a permanent magnet in the rotor, which improves the uniformity of the temperature distribution within the rotating electric machine, reduces the maximum temperature, and enables miniaturization and high output. Furthermore, it is possible to realize a rotating electric machine unit and an electric vehicle equipped with such a rotating electric machine. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram showing the system configuration of an electric vehicle according to Embodiment 1. [Figure 2] This is a cross-sectional view showing the schematic configuration of a rotating electric machine according to Embodiment 1. [Figure 3] This is a cross-sectional view showing the configuration of the rotor according to Embodiment 1. [Figure 4] This is a perspective view illustrating the configuration of one rotor pole according to Embodiment 1. [Figure 5] This is a cross-sectional view showing the configuration of the first block for one rotor pole according to Embodiment 1. [Figure 6] This is a cross-sectional view showing the configuration of the second block for one rotor pole according to Embodiment 1. [Figure 7] This figure shows the positions of the field magnets within the first block of the rotor according to Embodiment 1, using electrical angles. [Figure 8]It is a diagram showing the position of the field magnet in the second block of the rotor according to Embodiment 1 using electrical angle. [Figure 9] It is a cross-sectional view showing the configuration of the rotor and stator according to Embodiment 2. [Figure 10] It is a diagram showing the teeth portion of the axial end region according to Embodiment 2. [Figure 11] It is a diagram showing the teeth portion of the axial center region according to Embodiment 2. [Figure 12] It is a diagram showing the teeth portion of the axial center region according to another example of Embodiment 2. [Figure 13] It is a cross-sectional view showing the configuration of the rotor according to Embodiment 3. [Figure 14] It is a cross-sectional view showing the configuration of the first block of one pole of the rotor according to Embodiment 3. [Figure 15] It is a cross-sectional view showing the configuration of the second block of one pole of the rotor according to Embodiment 3. [Figure 16] It is a cross-sectional view showing the configuration of the rotor according to Embodiment 4. [Figure 17] It is a block diagram showing the system configuration of an electric vehicle according to Embodiment 5. [Figure 18] It is a cross-sectional view showing the configuration of the first block of one pole of the rotor according to Embodiment 6. [Figure 19] It is a cross-sectional view showing the configuration of the second block of one pole of the rotor according to Embodiment 6. [Figure 20] It is a cross-sectional view showing the schematic configuration of the rotating electrical machine unit according to Embodiment 7. [Figure 21] It is a partial detailed view of FIG. 20. [Figure 22] It is a cross-sectional view showing the schematic configuration of the rotating electrical machine unit according to Embodiment 8. [Figure 23] It is a partial detailed view of FIG. 22. [Figure 24] It is a cross-sectional view showing the configuration of the rotor according to Embodiment 9. [Figure 25] It is a cross-sectional view showing the configuration of one pole of the rotor according to Embodiment 9. [Figure 26] This figure shows the position of the field magnets in the rotor according to Embodiment 9, using electrical angles. [Figure 27] This is a cross-sectional view showing the configuration of one rotor pole according to Embodiment 10. [Figure 28] This is a block diagram showing the system configuration of an electric vehicle according to another example of Embodiment 10. [Figure 29] This is a cross-sectional view showing the schematic configuration of a rotating electric machine according to another example of Embodiments 1 to 10. [Modes for carrying out the invention]

[0013] Embodiment 1. Embodiment 1 will be described below with reference to the figures. Figure 1 is a block diagram showing the system configuration of an electric vehicle according to Embodiment 1. As shown in Figure 1, the electric vehicle 100 includes a motor which is a rotating electric machine 1 that drives the electric vehicle 100, a rotation sensor 2 provided on the rotating electric machine 1, an inverter 3 that drives and controls the rotating electric machine 1, and a battery 4 that supplies power to the inverter 3. Rotation sensor 2 may include resolvers, encoders, MR sensors (Magnetro Resistive Sensors), etc. Rotation sensor 2 acquires rotational speed information 2a, such as the angle or angular velocity of the rotating electric machine 1.

[0014] The inverter 3 is connected to the battery 4 and converts the DC power from the battery 4 into AC power, which is then supplied to the rotating electric machine 1. The current i of each phase (U phase, V phase, W phase) of the rotating electric machine 1 is detected, and this phase current i, along with the rotation speed information 2a from the rotation sensor 2, is fed back to the inverter 3. Furthermore, the inverter 3 receives a torque command T* and a rotational speed command N* for the electric vehicle 100. Based on the torque command T* and rotational speed command N*, along with the phase current i and rotational speed information 2a, the inverter 3 converts the DC power from the battery 4 into AC power and supplies voltage and current in the form of AC power to the rotating electric machine 1 to drive and control the rotating electric machine 1.

[0015] In this embodiment, the rotating electric machine 1 is a drive motor that is driven in the powering region for more than half of the lifecycle of the electric vehicle 100, that is, it is primarily used for powering operations. Furthermore, when the electric vehicle 100 moves forward, the rotation direction of the rotating electric machine 1 is set to forward rotation.

[0016] Figure 2 is a cross-sectional view showing the schematic configuration of the rotating electric machine 1, and shows a cross-section cut by a plane passing through the axis of the rotating electric machine 1. As shown in the figure, the rotating electric machine 1 comprises a cylindrical shaft 10, a cylindrical rotor 20 fixed to the shaft 10, and a cylindrical stator 30 positioned outside the rotor 20 with an air gap in between. The rotor 20 and the stator 30 are positioned with their axes 10A on the same center. The shaft 10 is rotatably supported by a bearing 41, which is fitted into a bracket 42, and the bracket 42 is fastened to the housing 43 by fastening elements such as screws. The stator 30 is fixed to the housing 43.

[0017] The inside of the rotating electric machine 1 is filled with air 50, which is a fluid, and the heat generated by the rotor 20 is dissipated through the air 50 and the shaft 10 inside the rotating electric machine 1. In other words, the rotor 20 is cooled by heat transfer through the air 50 and the shaft 10.

[0018] The stator 30 is an armature comprising a stator core 31 formed by stacking annular electromagnetic steel sheets in the axial direction, and coils 32 wound around each tooth (not shown) of the stator core 31. Multiple teeth are provided at equal intervals in the circumferential direction. The coil 32 has a coil portion arranged within a slot of the stator core 31 and coil end portions protruding from the stator core 31 on both axial sides. In Figure 2, the illustration of the coil portion arranged within the slot is omitted for convenience. In this case, the rotating electric machine 1 has a three-phase configuration (U-phase, V-phase, W-phase), and the stator 30 has three-phase coils as coils 32. The ends of each phase coil are connected to the AC terminals of the inverter 3. Note that the stator 30 may be provided with multiple sets of three-phase coils (for example, two sets).

[0019] Figure 3 is a cross-sectional view showing the configuration of the rotor 20, schematically representing a cross-section cut by a plane passing through the axis 10A of the rotating electric machine 1. Figure 4 is a perspective view illustrating the configuration of one pole of the rotor 20. As shown in Figures 3 and 4, the rotor 20 comprises a rotor core 21 and first and second permanent magnets 22A and 22B, which are field magnets, and is composed of multiple stages (in this case, four stages) of blocks 20A and 20B in the axial direction. Of the multiple stages of blocks 20A and 20B, the first block 20A on the axial end side comprises the first permanent magnet 22A, and the second block 20B on the axial center side comprises the second permanent magnet 22B.

[0020] The first and second blocks 20A and 20B are formed by stacking them axially with skew at each stage. The skew angle is set in machine angle to (±360° / number of poles / reduced order component / 2) so that the order component of the torque ripple that you want to reduce cancels out. In this case, the rotor 20 has 8 poles, and the angle is set to ±1.875° to reduce the 12th order component. The primary direction of rotation of the rotor 20, the forward rotation direction (arrow 60), is the direction in which the rotor 20 rotates when the electric vehicle 100 moves forward, and in Figure 4, this is the counterclockwise direction when viewed from the front. The positive direction of the skew angle is the forward rotation direction of the rotor 20.

[0021] The first and second blocks 20A and 20B are positioned so that their skew angles are symmetrical with respect to the axial direction. The skew angle of the first block 20A is set to +1.875°, and the skew angle of the second block 20B is set to -1.875°. Thus, the first permanent magnet 22A is positioned +1.875° ahead of the rotor 20 in the forward rotation direction, and the second permanent magnet 22B is positioned -1.875° behind the rotor 20 in the forward rotation direction.

[0022] Figure 5 is a cross-sectional view showing the configuration of the first block 20A for one pole of the rotor 20, and shows a cross-section perpendicular to the axial direction. As shown in Figure 5, the d-axis d1 of the first block 20A alone, which is the line connecting the center of the first permanent magnet 22A and the center of rotation, is located at a position advanced by θ1 (+1.875°) in the forward rotation direction (arrow 60) of the rotor 20 from the d-axis d0 of the rotor 20 as a whole. Figure 6 is a cross-sectional view showing the configuration of the second block 20B for one pole of the rotor 20, and shows a cross-section perpendicular to the axial direction. As shown in Figure 6, the d-axis d2 of the second block 20B alone, which is the line connecting the center of the second permanent magnet 22B and the center of rotation, is located at a position lag by θ2 (-1.875°) in the forward rotation direction (arrow 60) of the rotor 20 as a whole, relative to the d-axis d0 of the rotor 20.

[0023] When the d-axis d1 of the first block 20A and the d-axis d2 of the second block 20B are projected onto the same plane perpendicular to the axial direction, the vector D0 indicating the direction of the d-axis d0 of the entire rotor 20 is expressed by the following formula. D0=(L1 / (L1+L2))·D1+(L2 / (L1+L2))·D2 However, L1 is the axial length of the first block 20A, L2 is the axial length of the second block 20B, D1 is the two-dimensional direction vector when d1 is projected onto a plane, and D2 is the two-dimensional direction vector when d2 is projected onto a plane. In this case, L1 = L2, and d0 is located exactly halfway between d1 and d2.

[0024] When the rotating electric machine 1 is operated under power, a constant advance angle β is generally applied to utilize reluctance torque or to control magnetic flux weakening. This advance angle is based on the q-axis q0 of the rotor 20 as a whole. In the case of power operation, β takes a range of 0° < β < 90°. Figure 7 shows the positions of the field magnets within the first block 20A of the rotor 20 using electrical angles. As shown in Figure 7, the magnetic flux vector Q from the stator 30 has an advance angle β0 with respect to the q-axis q0 of the rotor 20 as a whole, and an advance angle β1 with respect to the q-axis q1 of the first block 20A. Furthermore, the d-axis d1 of the first block 20A is the position advanced from the d-axis d0 of the rotor 20 in the forward rotation direction of the rotor 20 (arrow 60). The advance angles β0 and β1 are related by the relationship β1 = β0 - θ1 × (number of poles), and in this case, β1 = β0 - 15°.

[0025] Figure 8 shows the positions of the field magnets within the second block 20B of the rotor 20 using electrical angles. As shown in Figure 8, the magnetic flux vector Q from the stator 30 has an advance angle β0 with respect to the q-axis q0 of the rotor 20 as a whole, and an advance angle β2 with respect to the q-axis q2 of the second block 20B. In addition, the d-axis d2 of the second block 20B is positioned lagging behind the d-axis d0 of the rotor 20 in the forward rotation direction of the rotor 20 (arrow 60). The advance angles β0 and β2 are related by the relationship β2 = β0 - θ2 × (number of poles), and in this case, β2 = β0 + 15°.

[0026] Since the advance angle β0 is based on the q-axis q0 of the rotor 20 as a whole, the advance angle β2 of the second block 20B, based on the q-axis q2, is greater than the advance angle β1 of the first block 20A, based on the q-axis q1. In other words, the advance angle of the second block 20B is closer to 90 degrees than that of the first block 20A, resulting in a larger amount of flux weakening. Generally, when flux weakening control is performed, the iron loss generated in the rotor 20 decreases, so the heat generated by the second block 20B is lower than that of the first block 20A. In other words, the first block 20A generates more heat than the second block 20B. Similarly, the first permanent magnet 22A generates more heat than the second permanent magnet 22B, making the first permanent magnet 22A a high-heat magnet and the second permanent magnet 22B a low-heat magnet.

[0027] In this embodiment, the first block 20A is positioned on the axial end side, and the second block 20B is positioned on the axial center side. As such, the first block 20A, which generates a high amount of heat, is positioned on the axial end side, resulting in a large contact area with the air 50 inside the rotating electric machine 1, making it easier to dissipate heat from the shaft end. Furthermore, since the first block 20A is also close to the end of the shaft 10, heat can easily be diffused to the outside air through the shaft 10. In this way, the heat dissipation capacity of the first block 20A, which generates more heat, is made greater than that of the second block 20B, resulting in a more uniform temperature distribution between the first block 20A and the second block 20B. As a result, the maximum temperature of the entire rotor 20 can be reduced, enabling a smaller and more powerful rotating electric machine 1.

[0028] Furthermore, the heat generated in the rotor 20 is mainly from the first and second permanent magnets 22A and 22B, which are field magnets. In this case, making the heat dissipation capacity of the first block 20A greater than that of the second block 20B is equivalent to making the heat dissipation capacity of the first permanent magnet 22A greater than that of the second permanent magnet 22B.

[0029] As described above, in this embodiment, based on the difference in heat generation levels between the first permanent magnet 22A and the second permanent magnet 22B, which generate heat in accordance with the operation of the rotating electric machine 1, the first permanent magnet 22A is designated as a high-heat-generating magnet and the second permanent magnet 22B as a low-heat-generating magnet. The rotor 20 is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. Therefore, the uniformity of the temperature distribution within the rotating electric machine 1 can be improved, reducing the maximum temperature and enabling the rotating electric machine 1 to be made smaller and more powerful.

[0030] Furthermore, in this embodiment, the rotor 20 is provided with multiple layers of blocks arranged axially, each layer consisting of at least one first block 20A having a first permanent magnet 22A for each pole and at least one second block 20B having a second permanent magnet 22B for each pole. Of the multiple layers of blocks, the blocks equipped with the high-heat-generating magnets are located at the axial end, and the blocks equipped with the low-heat-generating magnets are located at the axial center. Therefore, the heat dissipation capacity of the high-heat-generating magnet can be increased more easily and reliably than that of the low-heat-generating magnet, and the rotor 20 is effectively cooled.

[0031] In the above embodiment, the rotor 20 is configured as a four-stage block in the axial direction, but any number of stages other than four is acceptable as long as the first block 20A is located at the axial end and the second block 20B is located at the axial center. Furthermore, although the above embodiment shows the rotor 20 being cooled via air 50 and shaft 10, the fluid is not limited to air 50; for example, oil may be used.

[0032] Furthermore, when the rotating electric machine 1 performs regenerative operation, the second block 20B, in which the second permanent magnet 22B is positioned lagging behind the rotor 20 in the forward rotation direction, generates more heat than the first block 20A. The advance angle β mentioned above is in the range of 0° < β < 90° during powered operation, while it is in the range of 90° < β < 180° during regenerative operation. That is, during regeneration, the first block, which is positioned in a phase-advancing position, has β closer to 90 degrees, resulting in a larger amount of weakened magnetic flux and reduced heat generation. For this reason, the second block 20B generates more heat.

[0033] In the above embodiment, the rotating electric machine 1 was described as a drive motor that primarily performs powering operations. However, in an electric vehicle 100, a rotating electric machine that acts as a generator may be provided separately from the drive motor. When the rotating electric machine 1 is a generator that primarily performs regenerative operations, it is configured as follows.

[0034] If the rotating electric machine 1 is a generator that primarily performs regenerative operation, the second block 20B, in which the second permanent magnet 22B is positioned lagging behind the rotor 20 in the forward rotation direction, generates more heat than the first block 20A, in which the first permanent magnet 22A is positioned advancing in the forward rotation direction of the rotor 20. Similarly, the second permanent magnet 22B generates more heat than the first permanent magnet 22A, making the second permanent magnet 22B a high-heat magnet and the first permanent magnet 22A a low-heat magnet. The second block 20B is positioned on the axial end side of the rotor 20, and the first block 20A is positioned on the axial center side. Note that in Figures 3 and 4, the arrangement of the first block 20A and the second block 20B is reversed, and for convenience, the figures are omitted from the illustration.

[0035] In this case as well, the rotor 20 is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet (second permanent magnet 22B) being greater than that of the low-heat-generating magnet (first permanent magnet 22A). This improves the uniformity of the temperature distribution within the rotating electric machine 1, reduces the maximum temperature, and enables the rotating electric machine 1 to be made smaller and more powerful.

[0036] Embodiment 2. Next, Embodiment 2 will be described with reference to the figures. This second embodiment differs from the first embodiment in the configuration of the stator 30 compared to the rotating electric machine 1. Figure 9 is a cross-sectional view showing the configuration of the rotor and stator according to Embodiment 2, schematically showing a cross-section cut by a plane passing through the axis 10A of the rotating electric machine 1. As shown in Figure 9, the configuration of the rotor 20 is the same as in the first embodiment described above, and the stator core 31 of the stator 30, which is arranged outside the rotor 20 with an air gap in between, has teeth that differ in shape between the axial end region 31A of the stator core 31 and the axial central region 31B sandwiched between the axial end regions 31A on both sides.

[0037] The stator core 31 is made up of stacked teeth that protrude toward the rotor 20, in this case from the outer circumference toward the inner circumference, and is provided with multiple teeth made up of stacked teeth at equal intervals in the circumferential direction. Figure 10 shows the teeth portion of the axial end region 31A. Figure 11 shows the teeth portion of the axial central region 31B. As shown in Figure 10, the tooth portion 31AA in the axial end region 31A has a tip angle of x[°] and a base width of a[mm]. Also, as shown in Figure 11, the tooth portion 31BA in the axial central region 31B has a tip angle of y(>x)[°] and a base width of b(>a)[mm]. Note that a larger tip angle results in a larger tip width.

[0038] In this embodiment, the tooth portion 31AA in the axial end region 31A has a narrower tip width and base width than the tooth portion 31BA in the axial central region 31B. Therefore, the tooth portion 31AA in the axial end region 31A has a narrower magnetic path width than the tooth portion 31BA in the axial central region 31B, making it more susceptible to magnetic saturation. As a result, in the stator 30, the axial end region 31A has less loss than the axial central region 31B. In addition, the magnetic flux from the teeth portion 31AA of the axial end region 31A to the rotor 20 is reduced, and the losses generated in the rotor 20 in the corresponding region are also reduced.

[0039] As described above, in the rotor 20, a first block 20A with a high heat generation is arranged on the axial end side, and a second block 20B with a low heat generation is arranged on the axial center side. By combining this rotor 20 with a stator 30 in which the teeth portion 31AA of the axial end region 31A is narrower than the teeth portion 31BA of the axial center region 31B, the uniformity of the temperature distribution within the rotating electric machine 1 can be improved, and the maximum temperature can be further reduced. Furthermore, since the teeth portion 31AA of the axial end region 31A is narrower than the teeth portion 31BA of the axial central region 31B, winding of the coil 32 becomes easier.

[0040] In the stator core 31 according to the above embodiment, the teeth portion 31AA of the axial end region 31A has a narrower tip width and root width than the teeth portion 31BA of the axial central region 31B. However, a similar effect can be obtained if at least one of the tip width and root width is narrower.

[0041] Figure 12 shows the teeth portion of the axial central region 31B according to another example of Embodiment 2. In this case, the teeth portion 31AA shown in Figure 10 is used in the axial end region 31A. As shown in Figure 12, the tooth portion 31BB in the axial central region 31B has a tip angle z (>x) [°] and a base width b (>a) [mm]. In this case, the shape of the tooth portion 31BB is a so-called flange shape, where the width is wider only at the tip. In this example, since the tip width of the tooth portion 31BB is greater than the base width, the base width of the tooth portion 31BB may be the same as the base width of the tooth portion 31AA in the axial end region 31A.

[0042] Thus, the structure of the stator core 31, which combines multiple tooth sections 31AA and 31BB with different tip widths, is effective in reducing torque ripple and is particularly suitable for the rotating electric machine 1, which is operated in a way that is undesirable due to torque ripple.

[0043] Embodiment 3. Next, Embodiment 3 will be described with reference to the figures. In the first embodiment described above, the rotor 20 was constructed with four blocks in the axial direction. However, in this third embodiment, fluid is flowed in the axial direction, and the rotor is constructed with two blocks positioned on the upstream and downstream sides of the fluid. Figure 13 is a cross-sectional view showing the rotor configuration according to Embodiment 3, schematically illustrating a cross-section cut by a plane passing through the axis 10A of the rotating electric machine 1.

[0044] As shown in Figure 13, the rotor 200 comprises a rotor core 21 and first and second permanent magnets 22A and 22B, and is cooled by a fluid 51, which is oil, flowing through a through-hole 55 that penetrates in the axial direction. The rotor 200 is composed of a first block 200A on the upstream side of the fluid 51 in the axial direction and a second block 200B on the downstream side, with the first block 200A comprising the first permanent magnet 22A and the second block 200B comprising the second permanent magnet 22B.

[0045] Figure 14 is a cross-sectional view showing the configuration of the first block 200A for one pole of the rotor 200, and shows a cross-section perpendicular to the axial direction. Figure 15 is a cross-sectional view showing the configuration of the second block 200B for one pole of the rotor 200, and shows a cross-section perpendicular to the axial direction. The first block 200A, similar to Embodiment 1 above, includes a first permanent magnet 22A positioned at each pole in the forward rotation direction (arrow 60) of the rotor 200. The second block 200B, similar to Embodiment 1 above, includes a second permanent magnet 22B positioned at each pole in the forward rotation direction (arrow 60) of the rotor 200. In addition, a through hole 55 that penetrates axially is provided for each pole of the rotor 200 on the d axis d0 of the entire rotor 200.

[0046] As described in Embodiment 1 above, when the rotating electric machine 1 is operated under power, a constant advance angle is set with respect to the q-axis q0 of the rotor 200 as a whole, for the purpose of utilizing reluctance torque or controlling magnetic flux weakening. Similarly, in this embodiment as well, the advance angle of the second block 200B with respect to the q-axis is larger than the advance angle of the first block 200A with respect to the q-axis. That is, the advance angle of the second block 200B is closer to 90 degrees than that of the first block 200A, and because the amount of magnetic flux weakened is larger, the amount of heat generated is lower. In this case, the first permanent magnet 22A becomes a high-heat-generating magnet, and the second permanent magnet 22B becomes a low-heat-generating magnet.

[0047] In this embodiment, the rotating electric machine 1 is a drive motor that primarily performs powering operations, and a first block 200A with a high heat generation is placed upstream of the fluid 51 in the axial direction, while a second block 200B with a low heat generation is placed downstream. The fluid 51 flowing through the through hole 55 absorbs heat from the first block 200A and then absorbs heat from the second block 200B. The temperature of the fluid 51 in contact with the first block 200A is lower than the temperature of the fluid 51 in contact with the second block 200B, resulting in a high heat dissipation effect. Therefore, the temperatures of the first block 200A and the second block 200B can be made uniform.

[0048] In this way, the heat dissipation capacity of the first block 200A, which generates more heat, is made greater than that of the second block 200B, resulting in a more uniform temperature distribution between the first block 200A and the second block 200B. As a result, the maximum temperature of the entire rotor 200 can be reduced, enabling a smaller and more powerful rotating electric machine 1. In this case as well, making the heat dissipation capacity of the first block 200A greater than that of the second block 200B is equivalent to making the heat dissipation capacity of the first permanent magnet 22A greater than that of the second permanent magnet 22B.

[0049] In the above embodiment 3, the rotating electric machine 1 was described as a drive motor that mainly performs powering operations. However, if the rotating electric machine 1 is a generator that mainly performs regenerative operations, it will be configured as follows. In that case, as described above, the second permanent magnet 22B generates more heat than the first permanent magnet 22A, so the second permanent magnet 22B is a high-heat magnet and the first permanent magnet 22A is a low-heat magnet. The second block 200B, which generates more heat, is placed on the upstream side of the fluid 51 in the axial direction, and the first block 200A, which generates less heat, is placed on the downstream side.

[0050] In this case as well, the rotor 20 is cooled by heat transfer via the fluid 51, with the heat dissipation capacity of the high-heat-generating magnet (second permanent magnet 22B) being greater than that of the low-heat-generating magnet (first permanent magnet 22A). This improves the uniformity of the temperature distribution within the rotating electric machine 1, reduces the maximum temperature, and enables the rotating electric machine 1 to be made smaller and more powerful.

[0051] Embodiment 4. Next, Embodiment 4 will be described with reference to the figures. In the above embodiment 3, the rotor 200 was cooled by a fluid 51 flowing through through holes 55 provided for each pole of the rotor 200. In this embodiment 4, the rotor is cooled by a fluid flowing axially within the rotating electric machine 1 without providing through holes. Figure 16 is a cross-sectional view showing the rotor configuration according to Embodiment 4, schematically illustrating a cross-section cut by a plane passing through the axis 10A of the rotating electric machine 1. In this case, the rotating electric machine 1 is described as a drive motor that primarily performs powering operations.

[0052] As shown in Figure 16, the rotor 201 comprises a rotor core 21 and first and second permanent magnets 22A and 22B, and is cooled by a fluid 50A, which is air flowing in the axial direction. The rotor 201 is composed of a first block 20A upstream of the fluid 50A in the axial direction and a second block 20B downstream of the fluid 50A. The first block 20A comprises the first permanent magnet 22A, and the second block 20B comprises the second permanent magnet 22B. The configuration of the first and second blocks 20A and 20B is the same as in Embodiment 1 described above (see Figures 5 and 6). In this case as well, the first permanent magnet 22A is a high-heat magnet, and the second permanent magnet 22B is a low-heat magnet.

[0053] In this embodiment, as in the third embodiment described above, a first block 20A with a high heat generation rate is placed upstream of the fluid 50A in the axial direction, and a second block 20B with a low heat generation rate is placed downstream. The fluid 50A flowing in the axial direction absorbs heat from the first block 20A and then absorbs heat from the second block 20B. The temperature of the fluid 50A in contact with the first block 20A is lower than the temperature of the fluid 50A in contact with the second block 20B, resulting in a high heat removal effect. Therefore, the temperatures of the first block 20A and the second block 20B can be made uniform.

[0054] In this way, the heat dissipation capacity of the first block 20A, which generates more heat, is made greater than that of the second block 20B, resulting in a more uniform temperature distribution between the first block 20A and the second block 20B. As a result, the maximum temperature of the entire rotor 201 can be reduced, enabling a smaller and more powerful rotating electric machine 1. Furthermore, since it is a ventilated cooling type rotating electric machine 1 that does not require the provision of separate through holes, it can be realized with a simple configuration.

[0055] In the above embodiment 4, the rotating electric machine 1 was described as a drive motor that mainly performs powering operations. However, if the rotating electric machine 1 is a generator that mainly performs regenerative operations, it will be configured as follows. In that case, as described above, the second permanent magnet 22B generates more heat than the first permanent magnet 22A, so the second permanent magnet 22B is a high-heat magnet and the first permanent magnet 22A is a low-heat magnet. The second block 20B, which generates more heat, is placed upstream of the fluid 50A in the axial direction, and the first block 20A, which generates less heat, is placed downstream.

[0056] In this case as well, the rotor 201 is cooled by heat transfer via the fluid 50A, with the heat dissipation capacity of the high-heat-generating magnet (second permanent magnet 22B) being greater than that of the low-heat-generating magnet (first permanent magnet 22A). This improves the uniformity of the temperature distribution within the rotating electric machine 1, reduces the maximum temperature, and enables the rotating electric machine 1 to be made smaller and more powerful.

[0057] The fluids 51 and 50A used in embodiments 3 and 4 described above are not limited to oil or air; any fluid with high heat transfer performance is acceptable.

[0058] Embodiment 5. Next, Embodiment 5 will be described with reference to the figures. Figure 17 is a block diagram showing the system configuration of an electric vehicle according to Embodiment 5. As shown in Figure 17, the electric vehicle 100A comprises a motor which is a rotating electric machine 1 that drives the electric vehicle 100A, a rotation sensor 2 provided on the rotating electric machine 1, an inverter 3 that drives and controls the rotating electric machine 1, a battery 4 that supplies power to the inverter 3, and a flow path switch 5 provided on the rotating electric machine 1. The rotating electric machine 1, the rotating sensor 2, the inverter 3, and the battery 4 are the same as those described using Figure 1 of Embodiment 1 above, but the configuration of the rotor inside the rotating electric machine 1 is the same as in Embodiment 3 or 4 above.

[0059] In this case, an example using the rotating electric machine 1 according to Embodiment 3 described above is shown. As shown in Embodiment 3 above, the rotor 200 is cooled by a fluid 51 flowing axially through the through hole 55. The flow path switch 5 reverses the direction of the fluid 51 when switching between the motoring operation and the regenerative operation of the rotating electric machine 1. The flow path switch 5, for example, has a solenoid-type directional control valve inside and operates according to a switching command 3a from the inverter 3. When the driving condition of the rotating electric machine 1 changes from powering to regenerative braking, the inverter 3 issues a switching command 3a to the flow path switch 5, which reverses the direction in which the fluid 51 flows. As a result, the fluid 51 that flows from the first block 200A to the second block 200B during powering is reversed during regenerative braking and flows from the second block 200B to the first block 200A.

[0060] As described above, the first block 200A is equipped with a first permanent magnet 22A positioned advanced in the forward rotation direction of the rotor 200 for each pole, and the second block 200B is equipped with a second permanent magnet 22B positioned lagging behind in the forward rotation direction of the rotor 200 for each pole. Between the first block 200A and the second block 200B, the first block 200A generates more heat during powering, while the second block 200B generates more heat during regeneration.

[0061] In this embodiment, a flow path switch 5 that reverses the direction of fluid flow 51 is provided on the rotating electric machine 1. As a result, fluid 51 flows from the block with higher heat generation to the block with lower heat generation among the first block 200A and the second block 200B, not only during power generation but also during regeneration. Therefore, the rotor 200 can be effectively cooled, and the temperature distribution between the first block 200A and the second block 200B is made uniform even during regeneration, thereby reducing the maximum temperature of the entire rotor 200.

[0062] In the above embodiment, an example using the rotating electric machine 1 according to Embodiment 3 is shown, but the rotating electric machine 1 according to Embodiment 4 can also be used in the same way. In this case as well, when the driving condition of the rotating electric machine 1 changes from powering to regeneration, the inverter 3 gives a switching command 3a to the flow path switch 5, and the flow path switch 5 reverses the direction in which the fluid 50A flows. As a result, the fluid 50A that flows from the first block 20A to the second block 20B during powering is reversed during regeneration and flows from the second block 20B to the first block 20A. Therefore, the rotor 201 can be effectively cooled not only during powering but also during regeneration.

[0063] Furthermore, the flow path switch 5 is not limited to operating in response to commands from the inverter 3; it may also switch based on other information, such as the current value or angular velocity information of the rotating electric machine 1.

[0064] Furthermore, the above embodiment 5 can also be applied to a rotating electric machine 1, which is a generator that primarily performs regenerative operation. In this case, the second permanent magnet 22B is a high-heat-generating magnet, and the first permanent magnet 22A is a low-heat-generating magnet. The second block 20B, which generates more heat, is positioned upstream of the fluid 50A in the axial direction, and the first block 20A, which generates less heat, is positioned downstream. When the driving conditions of the rotating electric machine 1 change from regeneration to powering, the flow path switcher 5 reverses the direction in which the fluid 50A flows. As a result, the fluid 50A that flows from the second block 20B to the first block 20A during regeneration is reversed during powering and flows from the first block 20A to the second block 20B. Therefore, the rotor 201 can be effectively cooled not only during regeneration but also during powering.

[0065] Embodiment 6. Next, Embodiment 6 will be described with reference to the figures. The rotating electric machine 1 will be described primarily as a drive motor that performs powering operations. In the above embodiment 3, a through hole 55 that penetrates in the axial direction is provided on the d-axis d0 of the rotor 200, but in this embodiment 6, the through hole is provided at a different position. Figure 18 is a cross-sectional view showing the configuration of the first block 210A for one pole of the rotor 200, and shows a cross-section perpendicular to the axial direction. Figure 19 is a cross-sectional view showing the configuration of the second block 210B for one pole of the rotor 200, and shows a cross-section perpendicular to the axial direction.

[0066] In this embodiment 6, as in embodiment 3 above, the rotor 200 comprises a rotor core 21 and first and second permanent magnets 22A and 22B, and is cooled by a fluid 51, which is oil, flowing through a through hole 55A that penetrates in the axial direction. The rotor 200 is composed of a first block 210A on the upstream side of the fluid 51 in the axial direction and a second block 210B on the downstream side, with the first block 210A comprising the first permanent magnet 22A and the second block 210B comprising the second permanent magnet 22B.

[0067] The first block 210A includes a first permanent magnet 22A positioned at each pole in the forward rotation direction (arrow 60) of the rotor 200. The second block 210B includes a second permanent magnet 22B positioned at each pole in the forward rotation direction (arrow 60) of the rotor 200. In addition, each pole of the rotor 200 is provided with a through hole 55A that penetrates axially. The through-hole 55A is positioned on the d-axis d1 side of the first block 210A with respect to the d-axis d0 of the rotor 200. In other words, the through-hole 55A is located at a position where the distance DA from the through-hole 55A to the first permanent magnet 22A is shorter than the distance DB from the through-hole 55A to the second permanent magnet 22B.

[0068] Furthermore, in order to bring the first permanent magnet 22A and the second permanent magnet 22B to the same magnetic temperature, it is preferable that the ratio of distance DA to distance DB be the inverse ratio of the heat generated by the first and second permanent magnets 22A and 22B.

[0069] In this embodiment, the through-hole 55A, which penetrates in the axial direction, is positioned closer to the first permanent magnet 22A, which is a high-heat-generating magnet, than to the second permanent magnet 22B, which is a low-heat-generating magnet. As a result, the heat generated by the first permanent magnet 22A in the first block 210A is more easily dissipated into the fluid 51 flowing through the through-hole 55A than the heat generated by the second permanent magnet 22B in the second block 210B. Therefore, the heat dissipation capacity of the first permanent magnet 22A (high-heat-generating magnet) is greater than that of the second permanent magnet 22B (low-heat-generating magnet). In this way, the first block 210A, which generates more heat, can dissipate heat more efficiently than the second block 210B, which generates less heat, and the temperature distribution between the first block 210A and the second block 210B becomes more uniform. As a result, the maximum temperature of the entire rotor 200 can be reduced, enabling the rotating electric machine 1 to be made smaller and more powerful.

[0070] In this embodiment, the first block 210A is placed upstream of the fluid 51 and the second block 210B is placed downstream. Combined with the effect of the arrangement of the through-hole 55A, this further improves the heat dissipation of the first block 210A, which generates a lot of heat, and reduces the maximum temperature of the entire rotor 200.

[0071] The arrangement of the first block 210A and the second block 210B is not limited to the above embodiment. For example, they may be arranged in the same way as in Embodiment 1, or the first block 210A and the second block 210B may be arranged alternately in a total of four stages. In these cases as well, by providing the through hole 55A closer to the first permanent magnet 22A than to the second permanent magnet 22B, the heat dissipation of the first permanent magnet 22A becomes greater than that of the second permanent magnet 22B, thereby reducing the maximum temperature of the entire rotor 200.

[0072] In this embodiment as well, the fluid 51 is not limited to oil or air; any fluid with high heat transfer performance is acceptable.

[0073] Furthermore, the above embodiment 6 can also be applied to a rotating electric machine 1, which is a generator that primarily performs regenerative operation. In that case, the second permanent magnet 22B is a high-heat-generating magnet, and the first permanent magnet 22A is a low-heat-generating magnet. The second block 210B, which generates more heat, is positioned upstream of the fluid 51 in the axial direction, and the first block 210A, which generates less heat, is positioned downstream. In addition, a through-hole 55A is provided for each pole of the rotor 200, extending axially. In this case, the through-hole 55A is positioned on the d-axis d2 side of the second block 210B with respect to the d-axis d0 of the rotor 200. That is, the through-hole 55A is positioned so that the distance from the through-hole 55A to the second permanent magnet 22B is shorter than the distance from the through-hole 55A to the first permanent magnet 22A.

[0074] Therefore, the heat dissipation capacity of the second permanent magnet 22B (high-heat generating magnet) is greater than that of the first permanent magnet 22A (low-heat generating magnet), which reduces the maximum temperature of the rotor 200 as a whole.

[0075] Embodiment 7. Next, Embodiment 7 will be described with reference to the figures. The rotating electric machine 1 will be described as a drive motor that primarily performs powering operations. Figure 20 is a cross-sectional view showing the schematic configuration of the rotating electric machine unit according to Embodiment 7, and shows a cross-section cut by a plane passing through the axis of the rotating electric machine 1. Figure 21 is a detailed view of a part of Figure 20, and schematically shows the cross-section. As shown in the figure, the rotating electric machine unit 6 has a structure in which the rotating electric machine 1 and the inverter 3 that drives the rotating electric machine 1 are integrated, and the inverter 3 is located on one shaft end side of the rotating electric machine 1.

[0076] In this embodiment, the rotating electric machine 1 uses a rotor 201 in which a first block 20A and a second block 20B are arranged in two stages in the axial direction. The configuration of the rotating electric machine 1 other than the rotor 201 is the same as that of Embodiment 1 shown in Figure 2. The configuration of the first and second blocks 20A and 20B is also the same as that of Embodiment 1 (see Figures 5 and 6), with the first block 20A comprising a first permanent magnet 22A and the second block 20B comprising a second permanent magnet 22B.

[0077] As shown in the figure, the inverter 3 is positioned on the shaft end side, closer to the second block 20B, which generates less heat. In other words, the first block 20A, which generates more heat, is positioned away from the inverter 3, while the second block 20B, which generates less heat, is positioned closer to the inverter 3. When the rotating electric machine 1 is driven, not only the rotating electric machine 1 generates heat, but the inverter 3 also generates heat. In the rotating electric machine unit 6 according to this embodiment, the first block 20A, which generates a high amount of heat, is positioned away from the inverter 3, thereby reducing the thermal impact from the inverter 3 to the first block 20A.

[0078] Therefore, the heat dissipation capacity of the first permanent magnet 22A (high heat generation magnet) is greater than that of the second permanent magnet 22B (low heat generation magnet), the temperature distribution between the first block 20A and the second block 20B is made uniform, and the maximum temperature of the entire rotor 201 can be reduced.

[0079] In addition, in the above embodiment, as in the fourth embodiment, the first block 20A may be placed on the upstream side and the second block 20B on the downstream side, and the cooling fluid 50A may be flowed in the axial direction, further improving the uniformity of the temperature distribution.

[0080] Furthermore, similar to Embodiment 3 or Embodiment 6 above, a rotor 200 having through holes 55, 55A may be used to flow the cooling fluid 50A in the axial direction. In this case as well, by arranging the first blocks 200A and 210A, which generate a high amount of heat, at a position away from the inverter 3, the thermal influence from the inverter 3 to the first blocks 200A and 210A can be reduced, and the uniformity of the temperature distribution can be further improved.

[0081] Embodiment 8. Next, Embodiment 8 will be described with reference to the figures. The rotating electric machine 1 will be described primarily as a drive motor that performs powering operations. Figure 22 is a cross-sectional view showing the schematic configuration of the rotating electric machine unit according to Embodiment 8, and shows a cross-section cut by a plane passing through the axis of the rotating electric machine 1. Figure 23 is a detailed view of a part of Figure 22, and schematically shows the cross-section. As shown in the figure, the rotating electric machine unit 8 has a structure that includes a rotating electric machine 1 and a reduction gear 7 connected to the shaft 10 of the rotating electric machine 1 to adjust the rotational speed, with the reduction gear 7 being located on one end of the shaft of the rotating electric machine 1.

[0082] In this embodiment, the rotating electric machine 1 uses a rotor 201 in which a first block 20A and a second block 20B are arranged in two stages in the axial direction. The configuration of the rotating electric machine 1 other than the rotor 201 is the same as that of Embodiment 1 shown in Figure 2. The configuration of the first and second blocks 20A and 20B is also the same as that of Embodiment 1 (see Figures 5 and 6), with the first block 20A comprising a first permanent magnet 22A and the second block 20B comprising a second permanent magnet 22B.

[0083] As shown in the figure, the reduction gear 7 is positioned on the shaft end side, closer to the second block 20B, which generates less heat. In other words, the first block 20A, which generates more heat, is positioned away from the reduction gear 7, while the second block 20B, which generates less heat, is positioned closer to the reduction gear 7. When the rotating electric machine 1 is driven, not only the rotating electric machine 1 generates heat, but the reduction gear 7 also generates heat. In the rotating electric machine unit 8 according to this embodiment, the first block 20A, which generates a high amount of heat, is positioned away from the reduction gear 7, thereby reducing the thermal influence from the reduction gear 7 to the first block 20A.

[0084] Therefore, the heat dissipation capacity of the first permanent magnet 22A (high heat generation magnet) is greater than that of the second permanent magnet 22B (low heat generation magnet), the temperature distribution between the first block 20A and the second block 20B is made uniform, and the maximum temperature of the entire rotor 201 can be reduced.

[0085] In addition, in the above embodiment, as in the fourth embodiment, the first block 20A may be placed on the upstream side and the second block 20B on the downstream side, and the cooling fluid 50A may be flowed in the axial direction, further improving the uniformity of the temperature distribution.

[0086] Furthermore, similar to Embodiment 3 or Embodiment 6 above, a rotor 200 having through holes 55, 55A may be used to flow the cooling fluid 50A in the axial direction. In this case as well, by arranging the first blocks 200A and 210A, which generate a high amount of heat, at a position away from the reduction gear 7, the thermal influence from the inverter 3 to the first blocks 200A and 210A can be reduced, and the temperature distribution can be made even more uniform.

[0087] Although embodiments 7 and 8 described above assume that the rotating electric machine 1 is a drive motor that primarily performs powering operations, the embodiments can also be applied to a rotating electric machine 1 that is a generator that primarily performs regenerative operations. In that case, the second permanent magnet 22B is a high-heat-generating magnet, and the first permanent magnet 22A is a low-heat-generating magnet. The second block 20B, which generates more heat, is positioned upstream of the fluid 50A in the axial direction, and the first block 20A, which generates less heat, is positioned downstream. Furthermore, the inverter 3 (or reduction gear 7), which generates heat, is positioned closer to the shaft end where the first block 20A generates less heat. That is, the second block 20B, which generates more heat, is positioned away from the inverter 3 (or reduction gear 7), while the first block 20A, which generates less heat, is positioned closer to the inverter 3 (or reduction gear 7). As a result, similar to embodiments 7 and 8 described above, the temperature distribution between the first block 20A and the second block 20B is made uniform, and the maximum temperature of the entire rotor 201 can be reduced.

[0088] Embodiment 9. Next, Embodiment 9 will be described with reference to the figures. The rotating electric machine 1 will be described primarily as a drive motor that performs powering operations. In the embodiments described above, rotors 20, 200, and 201 having multiple blocks in the axial direction were used, but in this embodiment, a single configuration is used in the axial direction. Figure 24 is a cross-sectional view showing the rotor configuration according to Embodiment 9, schematically illustrating a cross-section cut by a plane passing through the axis 10A of the rotating electric machine 1. Figure 25 is a cross-sectional view showing the configuration of one rotor pole, with the cross-section perpendicular to the axial direction.

[0089] As shown in Figures 24 and 25, the rotor 220 comprises a rotor core 21 and first and second permanent magnets 22A and 22B, and is cooled by a fluid 51, which is oil, flowing through through holes 55A that penetrate in the axial direction. The rotor 220 is provided with a first permanent magnet 22A positioned advanced in the forward rotation direction of the rotor 220 (arrow 60), a second permanent magnet 22B positioned lagging behind, and a through hole 55A through which the fluid 51 flows, for each pole.

[0090] The first permanent magnet 22A and the second permanent magnet 22B are arranged symmetrically or nearly symmetrically with respect to the d-axis d0 of the rotor 220. The through hole 55A is located on the side of the first permanent magnet 22A with respect to the d-axis d0 of the rotor 220. That is, the through hole 55A is located at a position where the distance DA from the through hole 55A to the first permanent magnet 22A is shorter than the distance DB from the through hole 55A to the second permanent magnet 22B.

[0091] Figure 26 shows the positions of the field magnets within the rotor 220 using electrical angles. As described above, when the rotating electric machine 1 is operated under power, it is operated with a constant advance angle β (0° < β < 90°) relative to the q-axis q0, for the purpose of utilizing reluctance torque or controlling weakened magnetic flux. As shown in Figure 26, the magnetic flux vector Q from the stator 30 has an advance angle β0 with respect to the q-axis q0 of the rotor 220. Furthermore, with respect to the d-axis d0 of the rotor 220, the first permanent magnet 22A is positioned advanced in the forward rotation direction (arrow 60), and the second permanent magnet 22B is positioned lagging in the forward rotation direction (arrow 60).

[0092] When the rotor 220 is driven at an advance angle β0, the second permanent magnet 22B is more strongly affected by the weakening of the field flux than the first permanent magnet 22A. Therefore, the second permanent magnet 22B and the surrounding rotor core 21 generate less heat than the first permanent magnet 22A and the surrounding rotor core 21. In other words, the first permanent magnet 22A generates more heat than the second permanent magnet 22B, making the first permanent magnet 22A a high-heat magnet and the second permanent magnet 22B a low-heat magnet.

[0093] On the other hand, the heat transfer from the first and second permanent magnets 22A and 22B to the fluid 51 increases as the distance from the fluid 51 decreases. In other words, the first permanent magnet 22A, which is closer to the through-hole 55A through which the fluid 51 flows, dissipates heat more easily and has higher heat dissipation performance than the second permanent magnet 22B.

[0094] In this embodiment, each pole of the rotor 220 is equipped with a first permanent magnet 22A and a second permanent magnet 22B. Furthermore, a through hole 55A for which a fluid 51 flows axially is provided at each pole, closer to the first permanent magnet 22A (high heat generation magnet) than to the second permanent magnet 22B (low heat generation magnet). As a result, the heat generated by the first permanent magnet 22A is more easily dissipated by the fluid 51 flowing through the through hole 55A than the heat generated by the second permanent magnet 22B, and the heat dissipation capacity of the first permanent magnet 22A is greater than that of the second permanent magnet 22B. In this way, the first permanent magnet 22A, which generates more heat, can dissipate heat more efficiently than the second permanent magnet 22B, which generates less heat, thus uniformizing the temperature distribution of the rotor 220 and reducing the maximum temperature, which in turn allows for a smaller and more powerful rotating electric machine 1.

[0095] Furthermore, it is desirable that the through-hole 55A be provided in a position that does not interfere with the magnetic circuit, and that the distances DA and DB between each of the first and second permanent magnets 22A and 22B and the through-hole 55A be selected so as not to interfere with the magnetic circuit by the through-hole 55A. For example, the through-hole 55A should be provided in a position where the distance DA is as small as possible within the region where the magnetic flux density of the rotor core 21 is 0.1 [T] or less when the through-hole 55A is not provided.

[0096] Furthermore, in order to make the first permanent magnet 22A and the second permanent magnet 22B have the same magnetic temperature, the ratio of distance DA to distance DB may be the inverse ratio of the heat generated by the first and second permanent magnets 22A and 22B.

[0097] Although the above embodiment 9 was described as a drive motor in which the rotating electric machine 1 primarily performs powering operations, it can also be applied to a rotating electric machine 1 that is a generator primarily performing regenerative operations. In that case, the second permanent magnet 22B is a high-heat generating magnet, the first permanent magnet 22A is a low-heat generating magnet, and the through hole 55A is positioned on the second permanent magnet 22B side with respect to the d-axis d0 of the rotor 220. That is, the through hole 55A is provided at a position where the distance from the through hole 55A to the second permanent magnet 22B is shorter than the distance from the through hole 55A to the first permanent magnet 22A. As a result, the second permanent magnet 22B, which generates more heat, can dissipate heat more efficiently than the first permanent magnet 22A, which generates less heat, thus uniformizing the temperature distribution of the rotor 220 and reducing the maximum temperature, which in turn allows for a smaller and more powerful rotating electric machine 1.

[0098] Embodiment 10. Next, Embodiment 10 will be described with reference to the figures. The rotating electric machine 1 will be described as a drive motor that primarily performs powering operations. In the above embodiment 9, the rotor 220 had one through-hole 55A that penetrated axially for each pole, but in this embodiment, it has two through-holes. Figure 27 is a cross-sectional view showing the rotor configuration according to Embodiment 10, schematically illustrating a cross-section cut by a plane passing through the axis 10A of the rotating electric machine 1. In this embodiment as well, similar to embodiment 9 described above, the rotor 230 has a single configuration in the axial direction.

[0099] As shown in Figure 27, the rotor 230 is provided with a first permanent magnet 22A positioned in the forward direction of rotation of the rotor 230 (arrow 60), a second permanent magnet 22B positioned in a lagging position, and a first through-hole 55B and a second through-hole 55C through which the fluid 51 flows, for each pole. The first permanent magnet 22A and the second permanent magnet 22B are arranged symmetrically or nearly symmetrically with respect to the d axis d0 of the rotor 230. The first through hole 55B is located on the side of the first permanent magnet 22A with respect to the d axis d0 of the rotor 230, and the second through hole 55C is located on the side of the second permanent magnet 22B with respect to the d axis d0 of the rotor 230.

[0100] The first through-hole 55B and the second through-hole 55C are arranged symmetrically or nearly symmetrically with respect to the d-axis d0 of the rotor 230. The fluid 51 for cooling the rotor 230 flows through the first through-hole 55B and the second through-hole 55C in the same axial direction, but the velocity of the fluid flowing through the first through-hole 55B is set to be greater than the velocity of the fluid flowing through the second through-hole 55C. Furthermore, the first permanent magnet 22A generates more heat than the second permanent magnet 22B, making the first permanent magnet 22A a high-heat magnet and the second permanent magnet 22B a low-heat magnet.

[0101] In this embodiment, each pole of the rotor 230 is equipped with a first permanent magnet 22A and a second permanent magnet 22B, and further, a first through-hole 55B and a second through-hole 55C are provided for each pole through which a fluid 51 flows in the axial direction. The fluid 51 flowing in the axial direction is set to have a flow velocity greater than that of the first through-hole 55B than that of the second through-hole 55C. That is, the fluid 51 flows at high speed through the first through-hole 55B, which is located closer to the first permanent magnet 22A (high-heat magnet) that generates a high amount of heat, and flows at low speed through the second through-hole 55C, which is located closer to the second permanent magnet 22B (low-heat magnet) that generates a low amount of heat.

[0102] Since heat transfer from a solid to a fluid increases with increasing flow velocity, the heat generated by the first permanent magnet 22A escapes more easily into the fluid 51 than the heat generated by the second permanent magnet 22B, resulting in greater heat dissipation capacity for the first permanent magnet 22A than for the second permanent magnet 22B. In this way, the first permanent magnet 22A, which generates more heat, can dissipate heat more efficiently than the second permanent magnet 22B, which generates less heat, thus making the temperature distribution of the rotor 230 more uniform and reducing the maximum temperature, which in turn allows for a smaller and more powerful rotating electric machine 1.

[0103] Furthermore, in this embodiment, the rotor 230 can have a symmetrical structure with respect to the d-axis d0, which simplifies the design of the magnetic circuit.

[0104] Furthermore, the position of the first and second through holes 55B and 55C is not limited to any particular method, as long as it is symmetrical with respect to the d-axis d0 of the rotor 230. For example, flux barriers on the magnetic circuit can be used as the first and second through holes 55B and 55C.

[0105] Although the above embodiment 10 was described as a drive motor in which the rotating electric machine 1 mainly performs powering operations, it can also be applied to a rotating electric machine 1 that is a generator mainly performing regenerative operations. In that case, the second permanent magnet 22B is a high-heat-generating magnet and the first permanent magnet 22A is a low-heat-generating magnet, and the flow velocity of the fluid 51 flowing in the axial direction is set to be greater than the flow velocity of the fluid flowing through the second through-hole 55C than the flow velocity of the fluid flowing through the first through-hole 55B. That is, the fluid 51 flows at high speed through the second through-hole 55C which is located closer to the second permanent magnet 22B (high-heat-generating magnet) which generates a high amount of heat, and flows at low speed through the first through-hole 55B which is located closer to the first permanent magnet 22A (low-heat-generating magnet) which generates a low amount of heat. As a result, the second permanent magnet 22B, which generates more heat, can dissipate heat more efficiently than the first permanent magnet 22A, which generates less heat, thus uniformizing the temperature distribution of the rotor 230 and reducing the maximum temperature, which in turn enables the rotating electric machine 1 to be made smaller and more powerful.

[0106] Furthermore, in this embodiment, the rotating electric machine 1 may be equipped with a flow velocity switch 9 for switching the flow velocity of the fluid 51, as shown below. Figure 28 is a block diagram showing the system configuration of an electric vehicle according to another example of Embodiment 10. As shown in Figure 28, the electric vehicle 100B comprises a rotating electric machine 1, a rotation sensor 2, an inverter 3, a battery 4, and a flow rate switch 9 provided on the rotating electric machine 1. The flow velocity switch 9 reverses the relative speed of the fluid flowing through the first through-hole 55B and the fluid flowing through the second through-hole 55C when switching between the power operation and regenerative operation of the rotating electric machine 1.

[0107] When the driving condition of the rotating electric machine 1 changes from powering to regenerative braking, the inverter 3 gives a switching command 3a to the flow velocity switch 9, and the flow velocity switch 9 decreases the flow velocity of the fluid 51 flowing through the first through hole 55B and increases the flow velocity of the fluid 51 flowing through the second through hole 55C. In other words, the flow velocity switch 9 switches so that the flow velocity of the fluid 51 flowing through the first through hole 55B is less than the flow velocity of the fluid 51 flowing through the second through hole 55C. During powering of the rotating electric machine 1, the first permanent magnet 22A generates more heat, while during regeneration, the second permanent magnet 22B generates more heat. In this case, because the flow rate switch 9 is provided on the rotating electric machine 1, the rotor 230 can be effectively cooled not only during powering but also during regeneration.

[0108] In this way, by providing the flow rate switch 9, the rotor 230 can be effectively cooled during both powering and regenerative braking operations. Therefore, whether the primary operation of the rotating electric machine 1 is powering, regenerative braking, or both operations are performed to an equal degree, the rotor 230 can be cooled equally effectively.

[0109] In Embodiment 1 described above, an inner rotor type rotating electric machine 1 having a stator 30 on the outside of the rotor 20 was shown. However, each of Embodiments 1 to 10 may also use an outer rotor type rotating electric machine as shown in Figure 29, and similar effects can be obtained. Figure 29 is a cross-sectional view showing the schematic configuration of the rotating electric machine 1A, and shows a cross-section cut by a plane passing through the axis of the rotating electric machine 1A.

[0110] As shown in the figure, the rotating electric machine 1A comprises a cylindrical shaft 10, a cylindrical rotor 20, and a cylindrical stator 30 positioned inside the rotor 20 with an air gap in between. The rotor 20 and the stator 30 are positioned with their axis 10A being the same. The shaft 10 is rotatably supported by a bearing 41, which is fitted into a bracket 42, and the bracket 42 is fastened to a housing 43 by fastening elements such as screws. The stator 30 is an armature comprising a stator core 31 and coils 32 wound around each tooth (not shown) of the stator core 31.

[0111] Although this application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are conceivable within the scope of the art disclosed herein. These include, for example, modifying, adding or omitting at least one component, or even extracting at least one component and combining it with components of other embodiments. [Explanation of Symbols]

[0112] 1,1A Rotating electric machine, 3 Inverter, 5 Flow path switch, 6 Rotating electric machine unit, 7 Reducer, 8 Rotating electric machine unit, 9 Flow rate switch, 20 Rotor, 20A First block, 20B Second block, 22A First permanent magnet, 22B Second permanent magnet, 30 Stator, 31 Stator core, 31A Axial end region, 31B Axial central region, 31AA,31BA,31BB Teeth section, 32 Coil, 50 Air, 50A Fluid, 51 Fluid, 55,55A Through hole, 55B First through hole, 55C Second through hole, 100,100A,100B Electric vehicle, 200 Rotor, 200A First block, 200B Second block, 201 Rotor, 210A First block, 210B Second block, 220 Rotor, d0 The d-axis of the rotor.

Claims

1. A rotating electric machine for an electric vehicle comprising a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor, The forward rotation of the rotor is the primary direction of rotation, and is the direction of rotation when the electric vehicle moves forward. The first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor. Based on the difference in heat generation levels between the first permanent magnet and the second permanent magnet, which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet. The rotor is cooled by heat transfer via a fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. Rotating electric machine.

2. The rotor comprises multiple layers of blocks arranged axially, each consisting of at least one first block having the first permanent magnet for each pole and at least one second block having the second permanent magnet for each pole. Of the aforementioned multiple layers of blocks, the block equipped with the high-heat-generating magnet is positioned on the axial end side, and the block equipped with the low-heat-generating magnet is positioned on the axial center side. The rotating electric machine according to claim 1.

3. The stator core is formed by stacking teeth portions in the axial direction, with teeth portions protruding toward the rotor side, and the teeth portions in the axial end region are narrower in at least one of their tip width and root width than the teeth portions in the axial central region. The rotating electric machine according to claim 2.

4. A rotating electric machine comprising a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor, The first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor. Based on the difference in heat generation levels between the first permanent magnet and the second permanent magnet, which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The fluid flows axially to cool the rotor, The rotor comprises a first block having the first permanent magnet for each pole and a second block having the second permanent magnet for each pole, arranged in the axial direction. Of the first and second blocks, the block equipped with the high-heat magnet is located upstream of the fluid, and the block equipped with the low-heat magnet is located downstream of the fluid. Rotating electric machine.

5. The rotor is provided with through holes that penetrate axially through each pole, and the fluid flows through these through holes. The rotating electric machine according to claim 4.

6. The rotating electric machine is equipped with a switch that reverses the direction of the fluid flow, and when switching between the powered operation and the regenerative operation, the direction of the fluid is reversed. The rotating electric machine according to claim 4 or claim 5.

7. A rotating electric machine comprising a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor, The first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor. Based on the difference in heat generation levels between the first permanent magnet and the second permanent magnet, which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The rotor is provided with through holes that penetrate axially at each pole, and the fluid flows through these through holes to cool the rotor. The through-hole is provided at a position where the distance from the through-hole to the high-heat magnet is shorter than the distance from the through-hole to the low-heat magnet. Rotating electric machine.

8. The rotor is provided with the first permanent magnet and the second permanent magnet arranged symmetrically with respect to the d-axis for each pole. The rotating electric machine according to claim 7.

9. A rotating electric machine comprising a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor, The first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor. Based on the difference in heat generation levels between the first permanent magnet and the second permanent magnet, which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The rotor is provided with the first permanent magnet and the second permanent magnet arranged symmetrically with respect to the d-axis for each pole, and further provided with a first through hole and a second through hole that penetrate in the axial direction for each pole. The fluid flows through the first and second through holes in the same direction to cool the rotor. The first through-hole is located on the side of the d-axis where the first permanent magnet is located, and the second through-hole is located on the side of the d-axis where the second permanent magnet is located, and the first and second through-holes are arranged symmetrically with respect to the d-axis. Of the first and second through holes, the velocity of the fluid flowing through the through hole on the high-heat magnet side is greater than the velocity of the fluid flowing through the through hole on the low-heat magnet side. Rotating electric machine.

10. The rotating electric machine is equipped with a switch for switching the speed of the fluid, and when switching between the powering operation and the regenerative operation, the relative speed of the fluid flowing through the first through-hole and the speed of the fluid flowing through the second through-hole are reversed. The rotating electric machine according to claim 9.

11. The aforementioned rotating electric machine is a motor that primarily performs power-driving operations, the high-heat-generating magnet is the first permanent magnet, and the low-heat-generating magnet is the second permanent magnet. A rotating electric machine according to any one of claims 1 to 5, 9, or 10.

12. The rotating electric machine is a generator that primarily performs regenerative operation, the high-heat-generating magnet is the second permanent magnet, and the low-heat-generating magnet is the first permanent magnet. A rotating electric machine according to any one of claims 1 to 5, 9, or 10.

13. A rotating electric machine comprising a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor, and an inverter for driving and controlling the rotating electric machine, The first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor. Based on the difference in heat generation levels between the first permanent magnet and the second permanent magnet, which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The rotor comprises a first block having the first permanent magnet for each pole and a second block having the second permanent magnet for each pole, arranged in the axial direction. The inverter is located on one shaft end side of the rotating electric machine, on the side of the first and second blocks that is closer to the block containing the low-heat magnet. Rotating electric machine unit.

14. The invention comprises a rotating electric machine according to claim 4 or claim 5, and an inverter for driving and controlling the rotating electric machine, The inverter is installed on the shaft end side downstream of the fluid in the aforementioned rotating electric machine. Rotating electric machine unit.

15. The rotating electric machine described in claim 6 and an inverter connected to the rotating electric machine are provided. The aforementioned switch operates in response to a switching command from the inverter. Rotating electric machine unit.

16. The rotating electric machine described in claim 10 and an inverter connected to the rotating electric machine are provided. The aforementioned switch operates in response to a switching command from the inverter. Rotating electric machine unit.

17. A rotating electric machine comprising a cylindrical rotor having at least one first permanent magnet and at least one second permanent magnet for each pole, and a cylindrical stator having a stator core and windings and disposed with an air gap between it and the rotor, and a reduction gear connected to the rotating electric machine, The first permanent magnet is positioned advanced in the forward rotation direction of the rotor with respect to the d-axis of the rotor, and the second permanent magnet is positioned lagging behind the forward rotation direction of the rotor with respect to the d-axis of the rotor. Based on the difference in heat generation levels between the first permanent magnet and the second permanent magnet, which generate heat in accordance with the operation of the rotating electric machine, one of the first and second permanent magnets is designated as a high-heat-generating magnet and the other as a low-heat-generating magnet, and the rotor is cooled by heat transfer via fluid, with the heat dissipation capacity of the high-heat-generating magnet being greater than that of the low-heat-generating magnet. The rotor comprises a first block having the first permanent magnet for each pole and a second block having the second permanent magnet for each pole, arranged in the axial direction. The reduction gear is located on one shaft end side of the rotating electric machine, and is positioned on the side of the first and second blocks that is closer to the block containing the low-heat generating magnet. Rotating electric machine unit.

18. A rotating electric machine according to claim 4 or claim 5, and a reduction gear connected to the rotating electric machine, The reduction gear is installed on the shaft end side downstream of the fluid in the rotating electric machine. Rotating electric machine unit.

19. The aforementioned rotating electric machine is a motor that primarily performs power-driving operations, the high-heat-generating magnet is the first permanent magnet, and the low-heat-generating magnet is the second permanent magnet. A rotating electric machine unit according to any one of claims 13, 16, or 17.

20. The rotating electric machine is a generator that primarily performs regenerative operation, the high-heat-generating magnet is the second permanent magnet, and the low-heat-generating magnet is the first permanent magnet. A rotating electric machine unit according to any one of claims 13, 16, or 17.

21. An electric vehicle driven by a rotating electric machine according to any one of claims 1 to 5, 9, or 10.

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