Rotating electric machine and method for driving the rotating electric machine

Abstract

A rotating electric machine that satisfies the maximum performance required without increasing the size and has improved efficiency in the low torque region. The rotating electric machine (1) has a first rotary drive unit (200) and a second rotary drive unit (300) that share a rotating shaft (20). The first rotary drive unit is a radial gap type rotary drive unit that includes a first stator (220) and a first rotor (210), while the second rotary drive unit is an axial gap type rotary drive unit that includes a second stator (330) and a second rotor (310) that has a second rotor core (311) and a second rotor magnet (312) that are fastened to the rotating shaft and arranged axially on the first rotary drive unit side with respect to the second stator via a gap.

Description

[Technical field]

[0001] The present disclosure relates to a rotating electric machine and a method for driving a rotating electric machine. [Background technology]

[0002] Rotating electric machines used in electric vehicles are required to have high performance in terms of maximum torque and maximum output required to drive the vehicle. However, general rotating electric machines that meet such requirements have a problem in that their efficiency decreases in the low torque and low output ranges where they are actually used frequently. In particular, in the low torque range, efficiency decreases due to stator iron loss caused by field magnetomotive force and carrier harmonic iron loss caused by inverter drive. For this reason, it has been difficult for general rotating electric machines to satisfy maximum performance while also achieving high efficiency in the low torque range.

[0003] As a conventional rotating electric machine that addresses such problems, a rotating electric machine has been disclosed that improves efficiency in the low torque range by providing two rotation drive units on one rotating shaft (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2021-534717 [Patent Document 2] Special Publication No. 2020-501484 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional rotating electric machines, when two rotary drive parts are operated, mutual magnetic interference occurs between the two rotary drive parts. This magnetic interference causes the magnetic flux of one rotary drive part to interlink with the iron core of the other rotary drive part, resulting in loss. This causes a problem of reduced efficiency improvement effect in the low torque range. If the distance between the two rotary drive parts is increased to avoid magnetic interference, the rotating electric machine will become larger.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a rotating electric machine that satisfies the maximum performance required without increasing the size and has improved efficiency in the low torque range. [Means for solving the problem]

[0007] The rotating electric machine of the present disclosure has a frame, a rotating shaft rotatably supported by the frame, and a first rotation drive unit and a second rotation drive unit built into the frame and sharing the rotating shaft. The first rotation drive unit includes a first stator having a first stator core having an annular shape fixed to the frame and a plurality of first stator coils installed on the first stator core, and a first rotor iron fastened to the rotating shaft and disposed with a gap in the radial direction relative to the first stator. Heart The second rotary drive unit is a radial gap type rotary drive unit having at least one second stator fixed to a frame, and an axial gap type rotary drive unit having a second rotor fastened to a rotating shaft and having at least one second rotor core and a second rotor magnet installed on the second rotor core, the at least one second rotor core being arranged axially across a gap on the first rotary drive unit side relative to the second stator, and the at least one second rotor core is arranged on the first rotary drive unit side relative to all of the second stators, and the first rotary drive unit and the second rotary drive unit rotate synchronously. Effect of the Invention

[0008] In the rotating electric machine of the present disclosure, the second rotary drive unit is fixed to the frame. At least onea second stator, and a second stator fastened to the rotating shaft and disposed on the first rotary drive unit side with a gap in the axial direction with respect to the second stator. At least one A second rotor having a second rotor core and a second rotor magnet installed on the second rotor core. At least one second rotor core is disposed closer to the first rotary drive unit than all the second stators, and the first rotary drive unit and the second rotary drive unit rotate in synchronization with each other. Therefore, it is possible to satisfy the maximum performance required without increasing the size and to improve efficiency in the low torque range. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. [Diagram 2] 2 is a cross-sectional view of a first stator according to the first embodiment. FIG. [Diagram 3] FIG. 4 is a side view of a second load rotor according to the first embodiment. [Figure 4] FIG. 2 is a diagram for explaining the operation of the rotating electric machine according to the first embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of a rotating electric machine according to a second embodiment. [Figure 6] FIG. 11 is a cross-sectional view of a first rotor according to a second embodiment. [Figure 7] FIG. 11 is a cross-sectional view of a rotating electric machine according to a third embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a first rotor according to a third embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a rotating electric machine according to a fourth embodiment. [Figure 10] FIG. 11 is a cross-sectional view of a second stator according to a fourth embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a rotating electric machine according to a fifth embodiment. [Figure 12] FIG. 13 is a cross-sectional view of a rotating electric machine according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a rotating electric machine according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0011] Embodiment 1 Fig. 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. Fig. 1 is a cross-sectional view in a direction parallel to a rotating shaft described later. In the rotating electric machine 1 of this embodiment, the rotating shaft is connected to a load (not shown) on the right side of Fig. 1. Therefore, in Fig. 1, the right side is referred to as the load side, and the left side is referred to as the anti-load side.

[0012] The rotating electric machine 1 of this embodiment includes a first rotary drive unit 200 arranged on the load side and a second rotary drive unit 300 arranged on the counter-load side. The first rotary drive unit 200 and the second rotary drive unit 300 are built into one frame 100 and share one rotating shaft 20. The rotating shaft 20 is rotatably supported by a load side bearing 30 and a counter-load side bearing 40 relative to the frame 100. The load side end of the rotating shaft 20 is extended to the outside of the frame 100 and connected to the load. Hereinafter, the direction parallel to the rotating shaft 20 is referred to as the axial direction, the direction perpendicular to the rotating shaft 20 is referred to as the radial direction, and the direction in which the rotating shaft 20 rotates is referred to as the circumferential direction. The inner diameter side is the direction approaching the rotating shaft 20 in the radial direction, and the outer diameter side is the direction moving away from the rotating shaft 20 in the radial direction.

[0013] The frame 100 is composed of a cylindrical central frame 101 that covers the first rotary drive unit 200 and the second rotary drive unit 300 on the radial outside, a load side plate 102 that covers the load side end of the central frame 101, and a counter-load side plate 103 that covers the counter-load side end. A resolver rotor 51, which is a rotational position sensor that detects the rotational position of the rotary shaft 20, is fastened to the counter-load side end of the rotary shaft 20. A resolver stator 52 is fastened to the counter-load side plate 103 and is disposed with a gap between the resolver rotor 51 and the resolver stator 52. A resolver cover 53 that covers the resolver rotor 51 and the resolver stator 52 is attached to the counter-load side plate 103.

[0014] The first rotary drive unit 200 is an induction machine and is disposed on the load side in the rotating electric machine 1. The first rotary drive unit 200 has a first rotor 210 fastened to the rotating shaft 20 and a first stator 220 fastened to the central frame 101. The first rotor 210 and the first stator 220 are disposed with a gap in the radial direction. The first rotor 210 is composed of a first rotor core 211 having an annular shape fastened to the rotating shaft 20 and a first rotor coil 212. Although not shown, the first rotor core 211 has an annular main body and 59 teeth protruding from the main body to the outer diameter side. The first rotor coil 212 is a cage conductor disposed in a slot, which is a space between the teeth.

[0015] FIG. 2 is a cross-sectional view of the first stator according to this embodiment. The first stator 220 is composed of a first stator core 221 in an annular shape fastened to the central frame 101, and a first stator coil 222. The first stator core 221 has a main body in an annular shape and 48 teeth protruding from the main body to the inner diameter side. The first stator coil 222 is wound around the teeth in a distributed winding manner. The first rotary drive unit 200 thus configured is an 8-pole radial gap type cage induction machine. The radial gap type is a structure in which a gap exists between the rotor and the stator in the radial direction.

[0016] The second rotary drive unit 300 is a permanent magnet synchronous rotating machine, and is disposed on the anti-load side within the rotating electric machine 1. The second rotary drive unit 300 has a load side second rotor 310 and an anti-load side second rotor 320 fastened to the rotating shaft 20, and a second stator 330 fastened to the central frame 101. The load side second rotor 310 is disposed on the axial load side of the second stator 330 via a gap. The anti-load side second rotor 320 is disposed on the axial anti-load side of the second stator 330 via a gap.

[0017] The load side second rotor 310 is composed of a disk-shaped load side second rotor core 311 fastened to the rotating shaft 20, and a load side second rotor magnet 312. The load side second rotor magnet 312 is embedded in the surface of the load side second rotor core 311 facing the second stator 330. The load side second rotor magnets 312 are sector-shaped, and 24 of them are arranged at equal intervals in the circumferential direction, with the N poles and S poles alternately facing in the axial direction.

[0018] Fig. 3 is a side view of the load side second rotor 310 according to this embodiment. Fig. 3 is a side view of the load side second rotor 310 as viewed from the second stator 330 side. The load side second rotor 310 has 24 load side second rotor magnets 312 arranged at equal intervals in the circumferential direction on a disk-shaped load side second rotor core 311.

[0019] The counter-load side second rotor 320 is composed of a disk-shaped counter-load side second rotor core 321 fastened to the rotating shaft 20, and a counter-load side second rotor magnet 322. The counter-load side second rotor magnet 322 is embedded in the surface of the counter-load side second rotor core 321 facing the second stator 330. The counter-load side second rotor magnets 322 are sector-shaped, and 24 of them are arranged at equal intervals in the circumferential direction, with the N poles and S poles alternately facing the axial direction. The side surface of the counter-load side second rotor 320 seen from the second stator 330 side is similar to the side surface of the load side second rotor 310 shown in FIG. 3.

[0020] The load side second rotor magnet 312 of the load side second rotor 310 and the anti-load side second rotor magnet 322 of the anti-load side second rotor 320 are arranged so that the magnetic poles of the magnets at the same position in the circumferential direction face each other with their north and south poles facing the second stator 330.

[0021] The second stator 330 is composed of a second stator base 331 in an annular shape fastened to the central frame 101, and a second stator coil 332. The second stator base 331 has 72 slots formed at equal intervals at a mechanical angle pitch of 5 degrees in the circumferential direction. The second stator coil 332 is wound around these 72 slots at a 6-slot pitch. The second rotary drive unit 300 thus configured is an axial gap type permanent magnet synchronous rotating machine. The axial gap type is a structure in which a gap exists between a disk-shaped rotor and a stator in the axial direction.

[0022] Here, the materials will be described. The frame 100, the rotating shaft 20, the second stator 330, and the second stator base 331 are non-magnetic and are made of, for example, aluminum, resin, etc. These members are desirably made of resin, which is a non-conductive material, so that eddy current loss due to magnetic flux fluctuation does not occur. The first rotor core 211, the first stator core 221, the load side second rotor core 311, and the counter-load side second rotor core 321 are magnetic and are made of, for example, laminated electromagnetic steel sheets. The first rotor coil 212, the first stator coil 222, and the second stator coil 332 are made by winding a conductor wire made of, for example, copper, aluminum, iron, etc. The load side second rotor magnet 312 and the counter-load side second rotor magnet 322 are permanent magnets, for example, rare earth magnets.

[0023] Next, the operation of the rotating electric machine according to this embodiment will be described. FIG. 4 is a diagram showing the operation of the rotating electric machine according to the present embodiment. In FIG. 4, the horizontal axis represents the rotation speed, and the vertical axis represents the torque. Also, S MAX is the maximum rotation speed of the rotating electric machine 1, S H is the threshold value for the high rotation speed side, S L is the threshold value for the low rotation speed side, and S L H MAX Furthermore, T MAX is the maximum torque of the rotating electric machine 1, T H is the high torque threshold, T L is the threshold value for the low torque side, and T L ​​<T H <T MAX It is.

[0024] As shown in FIG. 4, the rotating electric machine 1 of the present embodiment has a torque that varies from 0 to T L The rotating electric machine 1 is driven only by the second rotary drive unit 300 until the rotation speed is increased from 0 to S L In the region up to and including the torque T L From T H The rotating electric machine 1 is driven only by the first rotary drive unit 200 until the rotation speed reaches 0 to S L In the region up to and including the torque T H From T MAX Up to this point, the rotation is driven by both the first rotary drive unit 200 and the second rotary drive unit 300.

[0025] The rotating electric machine 1 has a rotation speed of S L From S H In the region up to and including the torque T L From T H The rotary electric machine 1 is driven only by the first rotary drive unit 200 until the constant output curve of . L From S MAX In the region up to and including the torque T H From the constant power curve of T MAX 3, the rotary drive unit 200 and the second rotary drive unit 300 are driven by both of the rotary drive units.

[0026] In the rotating electric machine of this embodiment, when both rotary drive units are driven, the torque distribution is such that the second rotary drive unit 300 always provides the torque T L The first rotary drive unit 200 outputs the remaining required torque. L is the maximum torque that the second rotary drive unit 300 can output, and T H is the maximum torque that the first rotary drive unit 200 can output. MAX =T L +T H and T MAX is the maximum torque that the rotating electric machine 1 can output. Maximum rotation speed S of rotating electric machine 1 MAXThe second rotary drive unit 300 alone produces the maximum torque T L This is the maximum rotation speed at which the The threshold value for the low rotation speed is S L is the maximum rotation speed at which the first rotary drive unit 200 and the second rotary drive unit 300 can generate maximum torque.

[0027] When the rotating electric machine 1 is used in a region where the drive is switched between the first rotary drive unit 200 and the second rotary drive unit 300, the drive may be frequently switched. Frequent drive switching can be avoided by providing a hysteresis characteristic to the border line indicating the switching region shown in Fig. 4. For example, when the torque increases and decreases across the border line, frequent drive switching can be avoided by setting the threshold value that is the border line when the torque decreases to 95% of the threshold value that is the border line when the torque increases.

[0028] First, a case where this rotating electric machine 1 is driven only by the second rotary drive unit 300 will be described. In this rotating electric machine 1, the torque is T L In the following cases, the motor is driven only by the second rotary drive unit 300, which is an axial gap type permanent magnet synchronous rotating machine, so that it is possible to reduce iron loss caused by PWM carrier harmonics that are generated when the second rotary drive unit 300 is inverter-driven, thereby improving efficiency in the low torque range.

[0029] In addition, second rotary drive unit 300 has permanent magnets as field sources in load side second rotor 310 and anti-load side second rotor 320, but since second stator base 331 of second stator 330 is made of a non-magnetic material, no stator iron loss occurs due to the rotating magnetic field generated by the rotor field magnet. Therefore, the efficiency of rotating electric machine 1 can be improved.

[0030] When only the second rotary drive unit 300 is driven, the first rotary drive unit 200 also rotates in conjunction with it. However, since the first rotary drive unit 200 is an induction machine, no electromagnetic loss occurs due to the interlocking rotation.

[0031] Next, a case where this rotating electrical machine 1 is driven only by the first rotary drive unit 200 will be described. In this rotating electric machine, the region where only the first rotary drive unit 200, which is a squirrel-cage induction machine, is driven is not a low torque region where efficiency is low. Therefore, it is possible to suppress the decrease in efficiency in the low torque region. In addition, when only the first rotary drive unit 200 is driven, the second rotary drive unit 300 also rotates in conjunction with it. However, although the second rotary drive unit 300 is provided with a permanent magnet as a field source, the second stator base 331 of the second stator 330 is made of a non-magnetic material, so that no stator iron loss occurs due to the rotating magnetic field generated by the rotor field magnet. Therefore, it is possible to improve the efficiency of the rotating electric machine 1.

[0032] In addition, when the axial distance between the first rotary drive unit 200 and the second rotary drive unit 300 is shortened, the rotating magnetic field generated between the first rotor 210 and the first stator 220 of the first rotary drive unit 200 interlinks with the load side second rotor core 311 of the second rotary drive unit 300. However, since the rotating magnetic field generated in the first rotary drive unit 200 rotates at the same rotation speed as the load side second rotor core 311, it does not become an alternating magnetic field in the load side second rotor core 311. As a result, no iron loss occurs in the load side second rotor core 311. Therefore, even if the axial distance between the first rotary drive unit 200 and the second rotary drive unit 300 is shortened, the efficiency does not decrease. As a result, the rotating electric machine of this embodiment can be prevented from becoming large.

[0033] Furthermore, the load side second rotor core 311 of the second rotary drive unit 300 is disposed closer to the first rotary drive unit 200 than the second stator 330. The second rotary drive unit 300 and the first rotary drive unit 200 rotate synchronously. Therefore, the load side second rotor core 311 shields the rotating magnetic field of the first rotary drive unit 200, so that the rotating magnetic field of the first rotary drive unit 200 does not interlink with the second stator 330. As a result, the rotating electric machine 1 of this embodiment can improve efficiency without increasing its size.

[0034] Finally, a case where the rotating electric machine 1 is driven by both the first rotary drive unit 200 and the second rotary drive unit 300 will be described. The second rotary drive unit 300, which has a second stator base 331 made of a non-magnetic material and rotates using the field magnet of a permanent magnet, has high efficiency. In a region driven by both the first rotary drive unit 200 and the second rotary drive unit 300, the highly efficient second rotary drive unit 300 always generates maximum torque, thereby improving the maximum performance of the rotating electric machine 1.

[0035] In a rotating electric machine configured in this manner, it is possible to satisfy the maximum performance required without increasing the size and to improve the efficiency in the low torque range.

[0036] The second rotary drive unit 300, which is a permanent magnet synchronous rotating machine, is greatly influenced by the rotational position in terms of control. In the rotating electric machine of this embodiment, a resolver rotor 51, which is a rotational position sensor, is disposed at the end of the rotating shaft 20 on the anti-load side. Therefore, since the resolver rotor 51 is disposed in the vicinity of the second rotary drive unit 300, it is less influenced by the torsion of the rotating shaft 20, and the controllability of the second rotary drive unit 300 can be improved.

[0037] Embodiment 2 In the rotating electric machine according to the first embodiment, the first rotary drive unit is an eight-pole radial gap squirrel-cage induction machine. In the rotating electric machine according to the second embodiment, the first rotary drive unit is configured as a synchronous reluctance motor.

[0038] Fig. 5 is a cross-sectional view of a rotating electric machine according to this embodiment. The configuration of the rotating electric machine of this embodiment is similar to that of the rotating electric machine of embodiment 1 shown in Fig. 1, but the configuration of first rotary drive unit 200 is different from that of the first rotary drive unit of embodiment 1. First rotor 210 of this embodiment is composed only of annular first rotor core 211 fastened to rotating shaft 20. This first rotor core 211 is formed with a plurality of slits 213 penetrating in the axial direction.

[0039] FIG. 6 is a cross-sectional view of a first rotor according to this embodiment. FIG. 6 is a cross-sectional view in a direction perpendicular to the rotation axis. As shown in FIG. 6, first rotor 210 of this embodiment has a plurality of slits 213 formed in first rotor core 211. These slits 213 serve as flux barriers that form salient poles facing the inner diameter side. Eight sets of these flux barriers are formed at equal intervals in the circumferential direction. That is, rotating electric machine 1 of this embodiment has first rotary drive unit 200 configured as a synchronous reluctance motor.

[0040] The rotating electric machine 1 of this embodiment is driven in the same manner as the rotating electric machine of embodiment 1. Therefore, like the rotating electric machine of embodiment 1, it is possible to satisfy the required maximum performance without increasing the size and to improve the efficiency in the low torque region.

[0041] Embodiment 3 In the rotating electric machine according to the first embodiment, the first rotary drive unit is an eight-pole radial gap squirrel-cage induction machine. In the rotating electric machine according to the third embodiment, the first rotary drive unit is configured as a switched reluctance motor.

[0042] Fig. 7 is a cross-sectional view of a rotating electric machine according to this embodiment. The configuration of the rotating electric machine of this embodiment is similar to the configuration of the rotating electric machine of embodiment 1 shown in Fig. 1, but the configuration of first rotary drive unit 200 is different from the configuration of the first rotary drive unit of embodiment 1.

[0043] The first stator 220 in the rotating electric machine of this embodiment is composed of a first stator core 221 having an annular shape fastened to the central frame 101, and a first stator coil 222. Although not shown, the first stator core 221 has a main body having an annular shape and twelve teeth protruding from the main body to the inner diameter side. The first stator coil 222 is wound around the teeth in a concentrated winding manner.

[0044] The first rotor 210 of the present embodiment is composed only of a first rotor core 211 fastened to the rotating shaft 20. This first rotor core 211 is composed of a circular ring-shaped main body and eight protrusions 214 protruding from the main body to the outer diameter side.

[0045] Fig. 8 is a cross-sectional view of a first rotor according to this embodiment. Fig. 8 is a cross-sectional view in a direction perpendicular to the rotation axis. As shown in Fig. 8, first rotor 210 of this embodiment has eight protrusions 214 protruding from a ring-shaped main body of first rotor core 211 to the outer diameter side. The eight protrusions 214 are formed at equal intervals in the circumferential direction. That is, in rotating electric machine 1 of this embodiment, first rotary drive unit 200 is configured as a switched reluctance motor.

[0046] The rotating electric machine 1 of this embodiment is driven in the same manner as the rotating electric machine of embodiment 1. Therefore, like the rotating electric machine of embodiment 1, it is possible to satisfy the required maximum performance without increasing the size and to improve the efficiency in the low torque region.

[0047] Embodiment 4 In the rotating electric machine according to the first embodiment, the second rotary drive unit is an axial gap type permanent magnet synchronous rotating machine having no magnetic body in the stator. In the rotating electric machine according to the fourth embodiment, the second rotary drive unit has a magnetic stator.

[0048] Fig. 9 is a cross-sectional view of a rotating electric machine according to the present embodiment. The configuration of the rotating electric machine of the present embodiment is similar to the configuration of the rotating electric machine of the first embodiment shown in Fig. 1, but the configuration of second rotary drive unit 300 is different from the configuration of the second rotary drive unit of the first embodiment.

[0049] 10 is a cross-sectional view of a second stator according to this embodiment. The second stator 330 in the rotating electric machine of this embodiment is composed of a second stator core 333 having an annular shape fastened to a central frame 101, and a second stator coil 332. The second stator core 333 is composed of a magnetic material. The second stator core 333 has 48 teeth through which magnetic flux passes in the axial direction, and a teeth connection portion that connects the 48 teeth at the center in the axial direction. The circumferential width of the teeth connection portion is smaller than the circumferential width of the teeth. The second stator coil 332 is wound around the teeth.

[0050] In the rotating electric machine of this embodiment, since second rotary drive unit 300 has second stator core 333 made of a magnetic material, iron loss occurs due to PWM carrier harmonics that are generated when second rotary drive unit 300 is inverter-driven. In addition, when only first rotary drive unit 200 is driven, second rotary drive unit 300 also rotates in conjunction with it, and stator iron loss occurs due to a rotating magnetic field. Therefore, the efficiency of the rotating electric machine of this embodiment is lower than that of the rotating electric machine of embodiment 1.

[0051] However, in the rotating electric machine of this embodiment, second rotary drive unit 300 has second stator core 333 made of a magnetic material, so that the torque of second rotary drive unit 300 can be further improved.

[0052] Furthermore, in the rotating electric machine of this embodiment, the teeth connection parts that connect the teeth of second stator core 333 in the circumferential direction are small and do not function as a yoke, so there is almost no iron loss due to the magnetic flux passing through second stator core 333 in the circumferential direction. Therefore, there is less decrease in efficiency compared to general rotating electric machines.

[0053] Furthermore, the load side second rotor core 311 of the second rotary drive unit 300 is disposed closer to the first rotary drive unit 200 than the second stator core 333. The second rotary drive unit 300 and the first rotary drive unit 200 rotate synchronously. Therefore, the load side second rotor core 311 shields the rotating magnetic field of the first rotary drive unit 200, so that the rotating magnetic field of the first rotary drive unit 200 does not interlink with the second stator core 333. As a result, the rotating electric machine 1 of this embodiment can improve efficiency without increasing its size.

[0054] Embodiment 5. The rotating electric machine according to the fifth embodiment is obtained by removing the anti-load side second rotor from the rotating electric machine according to the fourth embodiment.

[0055] Fig. 11 is a cross-sectional view of a rotating electric machine according to this embodiment. The configuration of the rotating electric machine according to this embodiment is similar to that of the rotating electric machine according to the fourth embodiment shown in Fig. 9, but the configuration of the second rotary drive unit 300 is different from that of the second rotary drive unit according to the fourth embodiment. The second rotary drive unit 300 according to this embodiment has a load-side second rotor 310 fastened to the rotating shaft 20 and a second stator 330 fastened to the central frame 101. The load-side second rotor 310 is disposed on the axial load side of the second stator 330 via a gap.

[0056] The second stator 330 in the rotating electric machine of this embodiment is composed of a second stator core 333 having an annular shape fastened to the central frame 101, and a second stator coil 332. The second stator core 333 is composed of a magnetic material. The second stator core 333 has 48 teeth through which magnetic flux passes in the axial direction, and a teeth connection portion that connects the 48 teeth at the anti-load side end in the axial direction. The circumferential width of the teeth connection portion is larger than the circumferential width of the teeth. The second stator coil 332 is wound around the teeth.

[0057] In the rotating electric machine of this embodiment, the load side second rotor core 311 is arranged closer to the first rotary drive unit 200 than the second stator core 333. The second rotary drive unit 300 and the first rotary drive unit 200 rotate synchronously. Therefore, the load side second rotor core 311 shields the rotating magnetic field of the first rotary drive unit 200, so that the rotating magnetic field of the first rotary drive unit 200 does not interlink with the second stator core 333. As a result, the rotating electric machine 1 of this embodiment can improve efficiency without increasing the size, similar to the fourth embodiment.

[0058] Furthermore, in the rotating electric machine of this embodiment, since the second rotary drive section does not have a second rotor on the anti-load side, the number of parts can be reduced and the size can be reduced compared to the rotating electric machine of the fourth embodiment.

[0059] Embodiment 6 Fig. 12 is a cross-sectional view of a rotating electric machine according to the sixth embodiment. The configuration of the rotating electric machine of the present embodiment is similar to the configuration of the rotating electric machine of the first embodiment shown in Fig. 1, but the outer diameter of the second rotary drive part 300 is larger than the outer diameter of the first rotary drive part 200.

[0060] As shown in Figure 12, in the rotating electric machine 1 of this embodiment, the frame 100 is composed of a cylindrical load side central frame 101a that covers the first rotational drive unit 200 on the radial outside, a cylindrical anti-load side central frame 101b that covers the second rotational drive unit 300 on the radial outside, a load side plate 102 that covers the load side end of the load side central frame 101a, and an anti-load side plate 103 that covers the anti-load side end of the anti-load side central frame 101b.

[0061] The outer diameter of the counter-load side central frame 101b is larger than the outer diameter of the load side central frame 101a. Therefore, the outer diameter of the second rotary drive unit 300 disposed inside the counter-load side central frame 101b can be larger than the outer diameter of the first rotary drive unit 200 disposed inside the load side central frame 101a.

[0062] In the rotating electric machine configured in this manner, the torque of the second rotary drive portion 300 can be improved, and therefore the torque of the entire rotating electric machine can be improved.

[0063] In the first to sixth embodiments, the configurations of the number of poles and the number of slots of the first and second rotary drive units are exemplified, but the present invention is not limited to these configurations. For example, in the second embodiment, the first rotary drive unit has 8 poles and 48 slots, and the second rotary drive unit has 8 poles and 48 slots, but the first rotary drive unit may have 6 poles and 36 slots, and the second rotary drive unit may have 12 poles and 72 slots.

[0064] While the present disclosure describes various exemplary embodiments, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not exemplified are assumed within the scope of the technology disclosed in this specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment. [Explanation of symbols]

[0065] REFERENCE SIGNS LIST 1 rotating electric machine, 20 rotating shaft, 30 load side bearing, 40 counter load side bearing, 51 resolver rotor, 52 resolver stator, 53 resolver cover, 100 frame, 101 central frame, 101a load side central frame, 101b counter load side central frame, 102 load side plate, 103 counter load side plate, 200 first rotary drive section, 210 first rotor, 211 first rotor core, 212 first rotor coil, 213 slit, 214 protrusion, 220 first stator, 221 first stator core, 222 first stator coil, 300 second rotary drive section, 310 load side second rotor, 311 load side second rotor core, 312 load side second rotor magnet, 320 counter load side second rotor, 321 A second rotor core on the opposite load side, 322 a second rotor magnet on the opposite load side, 330 a second stator, 331 a second stator base, 332 a second stator coil, and 333 a second stator core.

Claims

1. A rotating electrical machine having a frame, a rotating shaft rotatably supported by the frame, and a first rotation driving unit and a second rotation driving unit built in the frame and sharing the rotating shaft, wherein the first rotation driving unit includes a first stator having an annular first stator core fixed to the frame and a plurality of first stator coils installed on the first stator core, and a first rotor core fastened to the rotating shaft and arranged radially with a gap from the first stator, and a first rotor having a first rotor coil installed on the first rotor core, and is a radial gap type rotation driving unit, the second rotation driving unit includes at least one second stator fixed to the frame, and at least one second rotor core fastened to the rotating shaft and arranged axially with a gap from the second stator on the first rotation driving unit side, and a second rotor having a second rotor magnet installed on the second rotor core, and is an axial gap type rotation driving unit, and at least one of the second rotor cores is arranged on the first rotation driving unit side with respect to all of the second stators, and the first rotation driving unit and the second rotation driving unit rotate synchronously. A rotating electrical machine characterized by that.

2. A rotating electrical machine having a frame, a rotating shaft rotatably supported by the frame, and a first rotation driving unit and a second rotation driving unit built in the frame and sharing the rotating shaft, wherein the first rotation driving unit includes a first stator having an annular first stator core fixed to the frame and a plurality of first stator coils installed on the first stator core, and a first rotor core fastened to the rotating shaft and arranged radially with a gap from the first stator, and a first rotor having a first rotor coil installed on the first rotor core, and is a radial gap type rotation driving unit, the second rotation driving unit includes a second stator fixed to the frame, and a second rotor core fastened to the rotating shaft and arranged axially with a gap from the second stator on the first rotation driving unit side, and a second rotor having a second rotor magnet installed on the second rotor core, and is an axial gap type rotation driving unit, and the second stator of the second rotation driving unit is made of a non-magnetic material. A rotating electrical machine characterized by that.

3. The rotating electrical machine according to claim 1 or 2, characterized in that the maximum output torque of the second rotation driving unit is smaller than the maximum output torque of the first rotation driving unit.

4. The rotating electrical machine according to claim 1 or 2, characterized in that the outer diameter of the second stator of the second rotation driving unit is larger than the outer diameter of the first stator of the first rotation driving unit.

5. The rotating electrical machine according to claim 1, characterized in that the second stator of the second rotation driving unit is made of a non-magnetic material.

6. The rotating electrical machine according to claim 1 or 2, characterized in that the second rotation driving unit further includes another second rotor fastened to the rotating shaft and located on the side opposite to the first rotation driving unit with respect to the second stator.

7. The rotating electrical machine according to claim 1 or 2, further comprising a rotation position sensor for detecting the rotation position of the rotating shaft, wherein the rotation position sensor is arranged at a position closer to the second rotation driving unit than to the first rotation driving unit.

8. A driving method for the rotating electrical machine according to claim 1 or 2, characterized in that when outputting a torque smaller than the maximum output torque of the second rotation driving unit, only the second rotation driving unit is driven.

Images