WO2020090448A1 - Rotating electric machine - Google Patents

Abstract

A rotating electric machine (10) is provided with: a field element (40) including a magnet portion (42) having a plurality of magnetic poles with alternate polarities in the circumferential direction; an armature (50) having multiple-phase armature windings (51); and cover members (30, 63) covering the field element and the armature. Of the inner surfaces of the cover members, a first opposing surface opposing coil ends (54, 55) of the armature windings is surface-processed to improve emissivity.

Description

Rotating electric machine Cross-reference of related applications

This application is based on Japanese application No. 2018-204498 filed on October 30, 2018, the content of which is incorporated herein by reference.

The disclosure in this specification relates to rotating electrical machines.

Conventionally, as an electric rotating machine, an IPM (Interior Permanent Magnet) type rotor in which a magnet accommodating hole is formed in a rotor core formed by laminating electromagnetic steel plates and a magnet is inserted into the magnet accommodating hole has been widely used. As a magnet used for such a rotor, for example, there is one shown in Patent Document 1. According to Patent Document 1, a magnet having a surface magnetic flux density distribution close to a sine wave can be provided, and eddy current loss can be suppressed due to a gentle change in magnetic flux as compared with a radial magnet. It also becomes possible to increase the magnetic flux density.

JP, 2014-93859, A

By the way, in the rotary electric machine as shown in Patent Document 1, in order to realize a high torque output, heat generation in the winding portion may be large.

The present disclosure has been made in view of the above problems, and an object thereof is to provide a rotating electric machine capable of improving cooling performance.

A first means for solving the above-mentioned problems is a field element having a magnet portion including a plurality of magnetic poles whose polarities alternate in the circumferential direction, an armature having a multi-phase armature winding, and the field. A rotating electric machine comprising: a magnet and a cover member that covers the armature, wherein any one of the field element and the armature rotates with a rotation shaft, and the armature is an inner surface of the cover member. The first facing surface facing the coil end of the winding is surface-treated to improve the emissivity.

The inner surface of the cover member, the first facing surface facing the coil end, is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end can be efficiently absorbed and the heat radiation on the coil side can be assisted.

According to a second aspect, in the first aspect, the field element has a cup-shaped magnet holding portion in which the magnet portion is fixed to an inner surface, and the field magnet is attached to the rotary shaft via the magnet holding portion. The emissivity is improved on a second opposing surface of the inner surface of the magnet holding portion, which is fixed and rotates together with the rotating shaft and faces the coil end of the armature winding. Surface treatment is done to make it.

▽ Of the inner surface of the magnet holding part, the second facing surface facing the coil end is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end can be efficiently absorbed and the heat radiation on the coil side can be assisted.

In the third means, in the second means, the outer surface of the magnet holding portion facing the second facing surface is surface-treated to improve the emissivity.

This will make it easier for heat to escape from the magnet holder to the outside. Therefore, the radiant heat from the coil end can be absorbed more efficiently, and the heat radiation on the coil side can be further assisted.

A fourth means is the second or third means, wherein an outer surface of the outer surface of the magnet holding portion facing the inner surface to which the magnet portion is fixed is surface-treated to improve emissivity.

With this, the heat of the magnet part can be radiated to the outside from the outer surface of the magnet holding part. Therefore, the heat dissipation of the magnet part can be assisted.

A fifth means is any one of the second to fourth means, wherein the third facing surface of the inner surface of the cover member facing the outer surface of the magnet holding portion is surface-treated to improve emissivity. Has been done.

With this, the heat released from the magnet holder can be efficiently absorbed by the cover member. Since the radiant heat from the coil end can be efficiently absorbed as the magnet holding portion radiates heat, it is possible to help the heat radiation on the coil side.

In a sixth means, in any one of the first to fifth means, an outer surface of the cover member facing the facing surface of the cover member is surface-treated to improve emissivity. There is.

With this, the heat of the cover member can be efficiently radiated from the outer surface to the outside. Therefore, the cover member can efficiently absorb the heat from the field element or the armature arranged inside the cover member and assist the heat dissipation.

In a seventh means, in any one of the first to sixth means, a plurality of electric components forming a power converter electrically connected to the armature winding, the magnet portion and the armature winding are provided. A cylindrical member provided on the inner side in the radial direction of the magnetic circuit part made of a wire, and a housing member to which the plurality of electric components are attached, and the cylindrical part has a refrigerant passage through which a refrigerant flows. The housing member is provided with the plurality of electrical components arranged radially inside the tubular portion and circumferentially along the tubular portion.

A cooling passage is provided inside the magnetic circuit in the radial direction. Therefore, the cooling performance to the outside in the radial direction or the outside in the axial direction of the magnetic circuit part is improved by surface processing of the cover member and the cooling performance to the inside in the radial direction of the magnetic circuit part is improved by the cooling passage. You can Therefore, as a whole, the cooling performance of the magnetic circuit unit can be further improved.

An eighth means is any one of the first to seventh means, wherein the magnet portion has a direction of an easy axis of magnetization on a side of a d-axis which is a magnetic pole center as compared with a side of a q-axis which is a magnetic pole boundary. Orientation is made so as to be parallel to the d-axis.

With this, the magnetic flux density on the d-axis can be improved and the output torque can be improved. Further, since the surface magnetic flux density distribution is close to a sine wave shape, it is possible to reduce eddy current and suppress heat generation. It should be noted that although there is a possibility that the heat generation of the magnetic circuit unit will increase as the output torque improves, the cooling performance is improved, so that it is possible to suppress a decrease in the magnetic flux density due to the heat generation.

As a ninth means, in any one of the first to eighth means, the magnet has an intrinsic coercive force of 400 [kA / m] or more and a residual magnetic flux density of 1.0 [T] or more. is there.

With this, the magnetic flux density on the d-axis can be improved and the output torque can be improved. It should be noted that although there is a possibility that the magnetic circuit unit will generate more heat as the output torque improves, the cooling performance is improved, so the effects of heat generation can be suppressed.

A tenth means is any one of the first to ninth means, wherein the armature winding has conductor portions arranged at predetermined intervals in a circumferential direction at a position facing the magnet portion. In the child, an inter-conductor member is provided between the conductor portions in the circumferential direction, and as the inter-conductor member, the circumferential width dimension of the inter-conductor member in one magnetic pole is Wt, and the saturation magnetic flux density of the inter-conductor member is Where Bs is Wm, the circumferential width of the magnet portion in one magnetic pole is Wm, and the residual magnetic flux density of the magnet portion is Br, a magnetic material or a non-magnetic material having a relationship of Wt × Bs ≦ Wm × Br. Or a structure in which an inter-conductor member is not provided between the conductor portions in the circumferential direction, and the conductor portion has a radial thickness dimension corresponding to one phase in one magnetic pole. Is smaller than the width dimension in the circumferential direction.

This will eliminate the torque limitation caused by magnetic saturation. It should be noted that although there is a possibility that the heat generation of the magnetic circuit unit will increase as the output torque improves, the influence can be suppressed because the cooling performance is improved.

An eleventh means is any one of the first to tenth means, wherein the armature winding has conductor portions arranged at predetermined intervals in a circumferential direction at positions facing the field element, The thickness of the conductive wire portion in the radial direction is smaller than the circumferential width of one phase in one magnetic pole.

This will reduce eddy current loss in the conductor part while improving torque. Further, since the cooling performance is improved while suppressing the eddy current loss in the conducting wire portion, the influence of heat generation in the magnetic circuit portion can be suppressed even if the output torque is improved.

A twelfth means is any one of the first to eleventh means, wherein the armature winding has conductor portions arranged at predetermined intervals in a circumferential direction at positions facing the field element, Each of the conductive wires forming the conductive wire portion is a bundle of a plurality of strands, and is a strand assembly in which the resistance value between the bundled strands is larger than the resistance value of the strands themselves.

∙ This can suppress eddy current loss in the conductor. Further, since the cooling performance is improved while suppressing the eddy current loss in the conductive wire portion, the influence of heat generation in the magnetic circuit portion can be suppressed even if the output torque is improved.

The above and other objects, features and advantages of the present disclosure will become more apparent by the following detailed description with reference to the accompanying drawings. The drawing is
1 is a vertical cross-sectional perspective view of a rotating electric machine, FIG. 2 is a vertical cross-sectional view of the rotating electric machine, 3 is a sectional view taken along line III-III of FIG. FIG. 4 is a cross-sectional view showing an enlarged part of FIG. FIG. 5 is an exploded view of the rotating electric machine, FIG. 6 is an exploded view of the inverter unit, FIG. 7 is a torque diagram showing the relationship between the ampere-turn of the stator winding and the torque density, FIG. 8 is a cross-sectional view of the rotor and the stator, FIG. 9 is an enlarged view of a part of FIG. FIG. 10 is a cross-sectional view of the stator, FIG. 11 is a longitudinal sectional view of the stator, FIG. 12 is a perspective view of the stator winding, FIG. 13 is a perspective view showing the configuration of the conductor wire, FIG. 14 is a schematic diagram showing the structure of the strands, FIG. 15 is a diagram showing the form of each conducting wire in the n-th layer, FIG. 16 is a side view showing the conductors of the nth layer and the (n + 1) th layer, FIG. 17 is a diagram showing the relationship between the electrical angle and the magnetic flux density for the magnet of the embodiment, FIG. 18 is a diagram showing the relationship between the electrical angle and the magnetic flux density for the magnet of the comparative example, FIG. 19 is an electric circuit diagram of the control system for the rotating electric machine, FIG. 20 is a functional block diagram showing current feedback control processing by the control device, FIG. 21 is a functional block diagram showing torque feedback control processing by the control device. FIG. 22 is a cross-sectional view of the rotor and the stator according to the second embodiment, FIG. 23 is an enlarged view showing a part of FIG. FIG. 24 is a diagram specifically showing the flow of magnetic flux in the magnet unit, FIG. 25 is a cross-sectional view of the stator according to Modification 1, FIG. 26 is a cross-sectional view of the stator according to Modification 1, FIG. 27 is a cross-sectional view of the stator according to the second modification, FIG. 28 is a cross-sectional view of a stator according to Modification 3, FIG. 29 is a cross-sectional view of the stator according to Modification 4, FIG. 30 is a cross-sectional view of a rotor and a stator according to Modification 7, FIG. 31 is a functional block diagram showing a part of the processing of the operation signal generation unit in Modification Example 8. FIG. 32 is a flowchart showing the procedure of the carrier frequency changing process, FIG. 33 is a diagram showing a connection form of each conductor wire which constitutes the conductor wire group in Modification 9. FIG. 34 is a diagram showing a configuration in which four pairs of conductors are arranged in a laminated manner in Modification 9. FIG. 35 is a cross-sectional view of an inner rotor type rotor and a stator in Modification 10. FIG. 36 is an enlarged view showing a part of FIG. FIG. 37 is a vertical cross-sectional view of an inner rotor type rotating electric machine, FIG. 38 is a vertical cross-sectional view showing a schematic configuration of an inner rotor type rotary electric machine, FIG. 39 is a diagram showing a configuration of a rotating electric machine having an inner rotor structure in Modification 11. 40: is a figure which shows the structure of the rotary electric machine of an inner rotor structure in the modification 11. FIG. 41 is a diagram showing a configuration of a rotary armature-type rotary electric machine in Modification 12. FIG. 42 is a cross-sectional view showing the structure of the conductor wire in the modified example 14, FIG. 43 is a diagram showing the relationship between reluctance torque, magnet torque, and DM, FIG. 44 is a diagram showing teeth, FIG. 45 is a perspective view showing a wheel of an in-wheel motor structure and its peripheral structure, FIG. 46 is a vertical cross-sectional view of the wheel and its peripheral structure, FIG. 47 is an exploded perspective view of a wheel, FIG. 48 is a side view of the rotary electric machine as viewed from the protruding side of the rotary shaft, 49 is a sectional view taken along line 49-49 of FIG. 48, 50 is a sectional view taken along line 50-50 of FIG. 49, FIG. 51 is an exploded sectional view of the rotating electric machine, 52 is a partial cross-sectional view of the rotor, FIG. 53 is a perspective view of a stator winding and a stator core, FIG. 54 is a front view showing the stator winding in a flat state. FIG. 55 is a diagram showing the skew of the conductive wire, FIG. 56 is an exploded sectional view of the inverter unit, FIG. 57 is an exploded sectional view of the inverter unit, FIG. 58 is a diagram showing a state of arrangement of each electric module in the inverter housing, FIG. 59 is a circuit diagram showing the electrical configuration of the power converter, FIG. 60 is a diagram showing an example of the cooling structure of the switch module, FIG. 61 is a diagram showing an example of the cooling structure of the switch module, FIG. 62 is a diagram showing an example of the cooling structure of the switch module, FIG. 63 is a diagram showing an example of the cooling structure of the switch module, FIG. 64 is a diagram showing an example of the cooling structure of the switch module, FIG. 65 is a diagram showing the arrangement order of the electric modules with respect to the cooling water passage, 66 is a sectional view taken along line 66-66 of FIG. 49, 67 is a cross-sectional view taken along line 67-67 of FIG. 49, FIG. 68 is a perspective view showing the bus bar module alone. FIG. 69 is a diagram showing an electrical connection state between each electric module and the bus bar module, FIG. 70 is a diagram showing an electrical connection state between each electric module and the bus bar module, FIG. 71 is a diagram showing an electrical connection state between each electric module and the bus bar module, FIG. 72 is a configuration diagram for explaining a modified example 1 of the in-wheel motor, FIG. 73 is a configuration diagram for explaining a second modification of the in-wheel motor, FIG. 74 is a configuration diagram for explaining Modification Example 3 of the in-wheel motor, FIG. 75 is a configuration diagram for explaining Modification Example 4 of the in-wheel motor, FIG. 76 is a vertical cross-sectional view of a rotor and a stator in Modification 15. FIG. 77 is a vertical cross-sectional view of a rotor and a stator in Modification 16.

A plurality of embodiments will be described with reference to the drawings. In embodiments, functionally and / or structurally corresponding parts and / or associated parts may be given the same reference sign or different reference signs in the hundreds or more. For the corresponding part and / or the related part, the description of other embodiments can be referred to.

The rotating electric machine in this embodiment is used as a vehicle power source, for example. However, the rotary electric machine can be widely used for industrial use, vehicle use, home electric appliance use, OA equipment use, game machine use, and the like. In each of the following embodiments, the same or equivalent portions are denoted by the same reference numerals in the drawings, and the description of the portions having the same reference numeral is cited.

(First embodiment)
The rotary electric machine 10 according to the present embodiment is a synchronous multi-phase AC motor and has an outer rotor structure (outer rotation structure). An outline of the rotary electric machine 10 is shown in FIGS. 1 to 5. 1 is a vertical cross-sectional perspective view of the rotary electric machine 10, FIG. 2 is a vertical cross-sectional view of the rotary electric machine 10 along a rotation axis 11, and FIG. 3 is a cross-sectional view perpendicular to the rotation axis 11. FIG. 3 is a cross-sectional view (cross-sectional view taken along the line III-III of FIG. 2) of the rotating electric machine 10, FIG. 4 is an enlarged sectional view showing a part of FIG. 3, and FIG. 5 is an exploded view of the rotating electric machine 10. Is. Note that, in FIG. 3, for convenience of illustration, the hatching showing the cut surface is omitted except for the rotating shaft 11. In the following description, the direction in which the rotary shaft 11 extends is defined as the axial direction, the direction that extends radially from the center of the rotary shaft 11 is the radial direction, and the direction that extends circumferentially around the rotary shaft 11 is the circumferential direction.

The rotary electric machine 10 roughly includes a bearing unit 20, a housing 30, a rotor 40, a stator 50, and an inverter unit 60. All of these members are arranged coaxially with the rotary shaft 11, and are assembled in the axial direction in a predetermined order to form the rotary electric machine 10. The rotating electric machine 10 of the present embodiment has a configuration including a rotor 40 as a “field element” and a stator 50 as an “armature”, and is embodied as a rotating field type rotating electric machine. It has become one.

The bearing unit 20 has two bearings 21 and 22 that are axially separated from each other, and a holding member 23 that holds the bearings 21 and 22. The bearings 21 and 22 are, for example, radial ball bearings, each having an outer ring 25, an inner ring 26, and a plurality of balls 27 arranged between the outer ring 25 and the inner ring 26. The holding member 23 has a cylindrical shape, and the bearings 21 and 22 are assembled inside the holding member 23 in the radial direction. The rotary shaft 11 and the rotor 40 are rotatably supported inside the bearings 21 and 22 in the radial direction. The bearings 21 and 22 configure a set of bearings that rotatably support the rotating shaft 11.

In each of the bearings 21 and 22, balls 27 are held by a retainer (not shown), and the pitch between the balls is maintained in that state. Each of the bearings 21 and 22 has a sealing member at the upper and lower portions in the axial direction of the retainer, and the inside thereof is filled with a non-conductive grease (for example, a non-conductive urea-based grease). Further, the position of the inner ring 26 is mechanically held by the spacer, and a constant pressure preload is applied so as to project vertically from the inside.

The housing 30 has a cylindrical peripheral wall 31. The peripheral wall 31 has a first end and a second end that face each other in the axial direction. The peripheral wall 31 has an end face 32 at the first end and an opening 33 at the second end. The opening 33 is opened at the entire second end. A circular hole 34 is formed in the center of the end surface 32, and the bearing unit 20 is fixed by a fixing tool such as a screw or a rivet while being inserted into the hole 34. A hollow cylindrical rotor 40 and a hollow cylindrical stator 50 are housed in the housing 30, that is, in the internal space defined by the peripheral wall 31 and the end surface 32. In the present embodiment, the rotary electric machine 10 is an outer rotor type, and the stator 50 is arranged inside the housing 30 inside the cylindrical rotor 40 in the radial direction. The rotor 40 is cantilevered by the rotary shaft 11 on the end face 32 side in the axial direction.

The rotor 40 has a magnet holder 41 formed in a hollow cylindrical shape and an annular magnet unit 42 provided inside the magnet holder 41 in the radial direction. The magnet holder 41 has a substantially cup shape and has a function as a magnet holding member. The magnet holder 41 includes a cylindrical portion 43 having a cylindrical shape, a fixing portion 44 having the same cylindrical shape and a diameter smaller than that of the cylindrical portion 43, and an intermediate portion which is a portion connecting the cylindrical portion 43 and the fixing portion 44. 45 and. The magnet unit 42 is attached to the inner peripheral surface of the cylindrical portion 43.

The magnet holder 41 is made of cold rolled steel plate (SPCC) having sufficient mechanical strength, forging steel, carbon fiber reinforced plastic (CFRP), or the like.

The rotary shaft 11 is inserted into the through hole 44a of the fixed portion 44. The fixed portion 44 is fixed to the rotary shaft 11 arranged in the through hole 44a. That is, the magnet holder 41 is fixed to the rotating shaft 11 by the fixing portion 44. The fixing portion 44 may be fixed to the rotating shaft 11 by spline connection using irregularities, key connection, welding, caulking, or the like. As a result, the rotor 40 rotates integrally with the rotating shaft 11.

Further, the bearings 21 and 22 of the bearing unit 20 are assembled on the radially outer side of the fixed portion 44. Since the bearing unit 20 is fixed to the end surface 32 of the housing 30 as described above, the rotary shaft 11 and the rotor 40 are rotatably supported by the housing 30. As a result, the rotor 40 is rotatable within the housing 30.

The rotor 40 is provided with the fixing portion 44 only on one of the two end portions opposed to each other in the axial direction, whereby the rotor 40 is cantilevered by the rotating shaft 11. Here, the fixed portion 44 of the rotor 40 is rotatably supported by the bearings 21 and 22 of the bearing unit 20 at two different axial positions. That is, the rotor 40 is rotatably supported by the two bearings 21 and 22 that are separated in the axial direction at one of the two end portions of the magnet holder 41 that face each other in the axial direction. Therefore, even if the rotor 40 is cantilevered by the rotary shaft 11, stable rotation of the rotor 40 is realized. In this case, the rotor 40 is supported by the bearings 21 and 22 at a position shifted to one side with respect to the axial center position of the rotor 40.

Further, in the bearing unit 20, the bearing 22 near the center of the rotor 40 (lower side in the figure) and the bearing 21 on the opposite side (upper side in the figure) are the gaps between the outer ring 25 and the inner ring 26 and the balls 27. The dimensions are different, and for example, the bearing 22 near the center of the rotor 40 has a larger clearance dimension than the bearing 21 on the opposite side. In this case, on the side closer to the center of the rotor 40, even if vibration of the rotor 40 or vibration due to imbalance due to component tolerance acts on the bearing unit 20, the effect of the vibration or vibration is well absorbed. It Specifically, by increasing the play size (gap size) in the bearing 22 near the center of the rotor 40 (the lower side in the drawing) by preload, the vibration generated in the cantilever structure is absorbed by the play part. It The preload may be a fixed position preload or a constant pressure preload. In the case of fixed position preload, both the bearing 21 and the outer ring 25 of the bearing 22 are joined to the holding member 23 by a method such as press fitting or adhesion. Further, both the bearing 21 and the inner ring 26 of the bearing 22 are joined to the rotating shaft 11 by a method such as press fitting or adhesion. Here, by arranging the outer ring 25 of the bearing 21 at different positions in the axial direction with respect to the inner ring 26 of the bearing 21, a preload can be generated. The preload can also be generated by disposing the outer ring 25 of the bearing 22 at different axial positions with respect to the inner ring 26 of the bearing 22.

Further, when the constant pressure preload is adopted, a preload spring, for example, a wave washer 24 or the like is used so that a preload is generated from an area sandwiched between the bearing 22 and the bearing 21 toward the outer ring 25 of the bearing 22 in the axial direction. It is arranged in the same region between 22 and the bearing 21. In this case as well, the inner races 26 of the bearing 21 and the bearing 22 are both joined to the rotary shaft 11 by a method such as press fitting or adhesion. The bearing 21 or the outer ring 25 of the bearing 22 is arranged with a predetermined clearance with respect to the holding member 23. With such a configuration, the spring force of the preload spring acts on the outer ring 25 of the bearing 22 in the direction away from the bearing 21. Then, as this force is transmitted through the rotary shaft 11, a force that pushes the inner ring 26 of the bearing 21 toward the bearing 22 acts. As a result, in both the bearings 21 and 22, the axial positions of the outer ring 25 and the inner ring 26 are displaced, and the two bearings can be preloaded in the same manner as the fixed position preload described above.

Note that it is not always necessary to apply a spring force to the outer ring 25 of the bearing 22 when generating the constant pressure preload, as shown in FIG. For example, a spring force may be applied to the outer ring 25 of the bearing 21. Further, one of the inner rings 26 of the bearings 21 and 22 is arranged with respect to the rotary shaft 11 with a predetermined clearance, and the outer ring 25 of the bearings 21 and 22 is press-fitted onto the holding member 23, or a method such as adhesion is used. The two bearings may be preloaded by joining them together.

Further, when a force is applied so that the inner ring 26 of the bearing 21 is separated from the bearing 22, it is better to apply a force so that the inner ring 26 of the bearing 22 is also separated from the bearing 21. On the contrary, when the force is applied so that the inner ring 26 of the bearing 21 approaches the bearing 22, it is better to apply the force so that the inner ring 26 of the bearing 22 also approaches the bearing 21.

When the rotary electric machine 10 is applied to a vehicle for the purpose of a vehicle power source or the like, there is a possibility that vibration having a component in the preload generation direction will be applied to the mechanism for generating the preload, or the target to which the preload is applied. The direction of gravity on an object may change. Therefore, when the present rotary electric machine 10 is applied to a vehicle, it is desirable to adopt the fixed position preload.

Further, the intermediate portion 45 has an annular inner shoulder portion 49a and an annular outer shoulder portion 49b. The outer shoulder portion 49b is located outside the inner shoulder portion 49a in the radial direction of the intermediate portion 45. The inner shoulder portion 49a and the outer shoulder portion 49b are separated from each other in the axial direction of the intermediate portion 45. As a result, the cylindrical portion 43 and the fixed portion 44 partially overlap each other in the radial direction of the intermediate portion 45. That is, the cylindrical portion 43 projects axially outward from the base end portion (lower end portion on the lower side in the drawing) of the fixing portion 44. In this configuration, as compared with the case where the intermediate portion 45 is provided in a flat plate shape without a step, it becomes possible to support the rotor 40 with respect to the rotation shaft 11 at a position near the center of gravity of the rotor 40. 40 stable operations can be realized.

According to the configuration of the intermediate portion 45 described above, the rotor 40 has a bearing accommodating recess 46 that accommodates a part of the bearing unit 20 at a position that surrounds the fixed portion 44 in the radial direction and is located inward of the intermediate portion 45. Is formed in an annular shape, and accommodates a coil end 54 of a stator winding 51 of a stator 50, which will be described later, at a position that surrounds the bearing accommodation recess 46 in the radial direction and is located outside the intermediate portion 45. 47 is formed. The housing recesses 46 and 47 are arranged so as to be adjacent to each other inside and outside in the radial direction. That is, a part of the bearing unit 20 and the coil end 54 of the stator winding 51 are arranged so as to overlap radially inward and outward. As a result, it is possible to reduce the axial length of the rotary electric machine 10.

The intermediate portion 45 is provided so as to project radially outward from the rotary shaft 11 side. Further, a contact avoidance portion that extends in the axial direction and that avoids contact with the coil end 54 of the stator winding 51 of the stator 50 is provided in the intermediate portion 45. The intermediate portion 45 corresponds to the projecting portion.

By bending the coil end 54 inward or outward in the radial direction, the axial dimension of the coil end 54 can be reduced, and the axial length of the stator 50 can be shortened. The bending direction of the coil end 54 may take into consideration the assembling with the rotor 40. Assuming that the stator 50 is assembled on the inner side of the rotor 40 in the radial direction, the coil end 54 may be bent inward in the radial direction on the insertion tip side of the rotor 40. The bending direction of the coil end on the opposite side of the coil end 54 may be arbitrary, but a shape bent outward with a spatial allowance is preferable in manufacturing.

Further, the magnet unit 42 as a magnet portion is composed of a plurality of permanent magnets arranged such that the polarities thereof are alternately changed along the circumferential direction inside the cylindrical portion 43 in the radial direction. As a result, the magnet unit 42 has a plurality of magnetic poles in the circumferential direction. However, details of the magnet unit 42 will be described later.

The stator 50 is provided inside the rotor 40 in the radial direction. The stator 50 has a stator winding 51 formed by winding in a substantially tubular shape (annular shape) and a stator core 52 as a base member arranged inside the stator winding 51. The line 51 is arranged so as to face the annular magnet unit 42 with a predetermined air gap interposed therebetween. The stator winding 51 is composed of a plurality of phase windings. Each of the phase windings is configured by connecting a plurality of conducting wires arranged in the circumferential direction to each other at a predetermined pitch. In the present embodiment, the U-phase, V-phase, and W-phase three-phase windings and the X-phase, Y-phase, and Z-phase three-phase windings are used, and by using these three-phase windings, The stator winding 51 is configured as a 6-phase winding.

The stator core 52 is formed in an annular shape by a laminated steel sheet in which electromagnetic steel sheets which are soft magnetic materials are laminated, and is assembled inside the stator winding 51 in the radial direction. The electromagnetic steel sheet is, for example, a silicon steel sheet obtained by adding about several percent (for example, 3%) of silicon to iron. The stator winding 51 corresponds to an armature winding, and the stator core 52 corresponds to an armature core.

The stator winding 51 is a portion that overlaps with the stator core 52 in the radial direction, and is a coil side portion 53 that is the radial outside of the stator core 52, and one end side of the stator core 52 in the axial direction and the other. It has coil ends 54 and 55 which respectively project to the end side. The coil side portions 53 respectively face the stator core 52 and the magnet unit 42 of the rotor 40 in the radial direction. In the state where the stator 50 is arranged inside the rotor 40, the coil end 54 on the bearing unit 20 side (upper side in the drawing) of the coil ends 54, 55 on both sides in the axial direction is the magnet holder of the rotor 40. It is housed in a coil housing recess 47 formed by 41. However, details of the stator 50 will be described later.

The inverter unit 60 has a unit base 61 fixed to the housing 30 with fasteners such as bolts, and a plurality of electric components 62 assembled to the unit base 61. The unit base 61 is made of, for example, carbon fiber reinforced plastic (CFRP). The unit base 61 has an end plate 63 fixed to the edge of the opening 33 of the housing 30, and a casing 64 integrally provided with the end plate 63 and extending in the axial direction. The end plate 63 has a circular opening 65 at the center thereof, and a casing 64 is formed so as to stand upright from the peripheral edge of the opening 65.

The stator 50 is attached to the outer peripheral surface of the casing 64. That is, the outer diameter of the casing 64 is the same as the inner diameter of the stator core 52 or slightly smaller than the inner diameter of the stator core 52. By mounting the stator core 52 on the outer side of the casing 64, the stator 50 and the unit base 61 are integrated. Further, since the unit base 61 is fixed to the housing 30, the stator 50 is integrated with the housing 30 when the stator core 52 is assembled to the casing 64.

The stator core 52 is preferably attached to the unit base 61 by adhesion, shrink fitting, press fitting, or the like. As a result, the positional deviation of the stator core 52 from the unit base 61 side in the circumferential direction or the axial direction is suppressed.

The inside of the casing 64 in the radial direction is a housing space for housing the electric component 62, and the electric component 62 is arranged in the housing space so as to surround the rotating shaft 11. The casing 64 has a role as a housing space forming portion. The electric component 62 is configured to include a semiconductor module 66 that constitutes an inverter circuit, a control board 67, and a capacitor module 68.

The unit base 61 is provided inside the stator 50 in the radial direction, and corresponds to a stator holder (armature holder) that holds the stator 50. The housing 30 and the unit base 61 form a motor housing of the rotary electric machine 10. In this motor housing, the holding member 23 is fixed to the housing 30 on one side in the axial direction across the rotor 40, and the housing 30 and the unit base 61 are coupled to each other on the other side. For example, in an electric vehicle, which is an electric vehicle, etc., the rotating electric machine 10 is attached to the vehicle by mounting the motor housing on the side of the vehicle or the like.

Here, the configuration of the inverter unit 60 will be further described by using FIG. 6 which is an exploded view of the inverter unit 60 in addition to FIGS. 1 to 5 described above.

In the unit base 61, the casing 64 has a tubular portion 71 and an end surface 72 provided at one of both ends (end portion on the bearing unit 20 side) facing each other in the axial direction. Of the both axial ends of the tubular portion 71, the opposite side to the end surface 72 is entirely opened through the opening 65 of the end plate 63. A circular hole 73 is formed in the center of the end surface 72, and the rotary shaft 11 can be inserted into the hole 73. The hole 73 is provided with a seal material 171 that seals a gap between the hole 73 and the outer peripheral surface of the rotary shaft 11. The sealing material 171 may be a sliding seal made of a resin material, for example.

The tubular portion 71 of the casing 64 serves as a partition portion that partitions between the rotor 40 and the stator 50 arranged radially outside thereof and the electric component 62 arranged radially inside thereof. The rotor 40, the stator 50, and the electric component 62 are arranged side by side inside and outside in the radial direction with the shape portion 71 interposed therebetween.

The electric component 62 is an electric component that constitutes an inverter circuit, and has a power running function of rotating the rotor 40 by supplying a current to each phase winding of the stator winding 51 in a predetermined order, and the rotating shaft 11 It has a power generation function of inputting a three-phase alternating current flowing through the stator winding 51 with the rotation of the above and outputting it as generated power to the outside. The electric component 62 may have only one of the power running function and the power generation function. The power generation function is, for example, a regenerative function of outputting regenerative electric power to the outside when the rotating electric machine 10 is used as a vehicle power source.

As a specific configuration of the electric component 62, as shown in FIG. 4, a hollow cylindrical capacitor module 68 is provided around the rotating shaft 11, and a plurality of capacitor modules 68 are provided on the outer peripheral surface of the capacitor module 68. The semiconductor modules 66 are arranged side by side in the circumferential direction. The capacitor module 68 includes a plurality of smoothing capacitors 68a connected in parallel with each other. Specifically, the capacitor 68a is a laminated film capacitor formed by laminating a plurality of film capacitors, and has a trapezoidal cross section. The capacitor module 68 is configured by arranging twelve capacitors 68a side by side in a ring shape.

In the manufacturing process of the capacitor 68a, for example, a long film having a predetermined width formed by laminating a plurality of films is used, and the film width direction is the trapezoidal height direction, and the trapezoidal upper and lower trapezoids alternate. By cutting the long film into an isosceles trapezoidal shape, the capacitor element is produced. Then, the capacitor 68a is manufactured by attaching an electrode or the like to the capacitor element.

The semiconductor module 66 has semiconductor switching elements such as MOSFETs and IGBTs, and is formed in a substantially plate shape. In the present embodiment, the rotary electric machine 10 includes two sets of three-phase windings, and since an inverter circuit is provided for each of the three-phase windings, a total of twelve semiconductor modules 66 are formed in a ring. The assembled semiconductor module group 66A is provided in the electrical component 62.

The semiconductor module 66 is arranged so as to be sandwiched between the cylindrical portion 71 of the casing 64 and the capacitor module 68. The outer peripheral surface of the semiconductor module group 66A is in contact with the inner peripheral surface of the tubular portion 71, and the inner peripheral surface of the semiconductor module group 66A is in contact with the outer peripheral surface of the capacitor module 68. In this case, the heat generated in the semiconductor module 66 is transmitted to the end plate 63 via the casing 64 and is radiated from the end plate 63.

The semiconductor module group 66A preferably has a spacer 69 between the semiconductor module 66 and the cylindrical portion 71 in the outer peripheral surface side, that is, in the radial direction. In this case, in the capacitor module 68, the cross-sectional shape of the cross section orthogonal to the axial direction is a regular dodecagon, while the cross-sectional shape of the inner peripheral surface of the tubular portion 71 is circular. Is a flat surface and the outer peripheral surface is a curved surface. The spacer 69 may be integrally provided so as to be continuous in an annular shape on the radially outer side of the semiconductor module group 66A. The spacer 69 is a good heat conductor, and may be a metal such as aluminum or a heat dissipation gel sheet. It should be noted that the cross-sectional shape of the inner peripheral surface of the tubular portion 71 can be the same dodecagonal shape as the capacitor module 68. In this case, both the inner peripheral surface and the outer peripheral surface of the spacer 69 may be flat surfaces.

Further, in the present embodiment, the tubular portion 71 of the casing 64 is provided with the cooling water passage 74 for circulating the cooling water, and the heat generated in the semiconductor module 66 is applied to the cooling water flowing through the cooling water passage 74. Is also released. That is, the casing 64 has a water cooling mechanism. As shown in FIGS. 3 and 4, the cooling water passage 74 is formed in an annular shape so as to surround the electric component 62 (semiconductor module 66 and capacitor module 68). The semiconductor module 66 is arranged along the inner peripheral surface of the cylindrical portion 71, and a cooling water passage 74 is provided at a position overlapping the semiconductor module 66 inward and outward in the radial direction.

Since the stator 50 is arranged outside the cylindrical portion 71 and the electric component 62 is arranged inside, the heat of the stator 50 is transferred to the cylindrical portion 71 from the outside, The heat of the electric component 62 (for example, the heat of the semiconductor module 66) is transmitted from the inside. In this case, the stator 50 and the semiconductor module 66 can be cooled at the same time, and the heat of the heat generating member in the rotary electric machine 10 can be efficiently released.

Further, at least a part of the semiconductor module 66 forming part or all of the inverter circuit that operates the rotating electric machine by energizing the stator windings 51 is located outside the tubular portion 71 of the casing 64 in the radial direction. The stator core 52 is arranged in a region surrounded by the stator core 52. Desirably, one semiconductor module 66 is wholly arranged in a region surrounded by the stator core 52. Further, preferably, all the semiconductor modules 66 are entirely arranged in the area surrounded by the stator core 52.

Further, at least a part of the semiconductor module 66 is arranged in the area surrounded by the cooling water passage 74. Desirably, all the semiconductor modules 66 are entirely arranged in a region surrounded by the yoke 141.

The electrical component 62 also includes an insulating sheet 75 provided on one end face of the capacitor module 68 and a wiring module 76 provided on the other end face in the axial direction. In this case, the capacitor module 68 has two end faces that face each other in the axial direction, that is, a first end face and a second end face. The first end surface of the capacitor module 68 near the bearing unit 20 faces the end surface 72 of the casing 64, and is superposed on the end surface 72 with the insulating sheet 75 interposed therebetween. A wiring module 76 is attached to the second end surface of the capacitor module 68 near the opening 65.

The wiring module 76 has a circular plate-shaped main body portion 76a made of a synthetic resin material and a plurality of bus bars 76b and 76c embedded therein. The bus bars 76b and 76c allow the semiconductor module 66 and the capacitor to be formed. An electrical connection is made with the module 68. Specifically, the semiconductor module 66 has a connection pin 66a extending from the axial end surface thereof, and the connection pin 66a is connected to the bus bar 76b on the outer side in the radial direction of the main body portion 76a. Further, the bus bar 76c extends to the side opposite to the capacitor module 68 on the outer side in the radial direction of the main body portion 76a, and is connected to the wiring member 79 at the tip portion thereof (see FIG. 2).

As described above, according to the configuration in which the insulating sheet 75 is provided on the first end surface of the capacitor module 68 facing in the axial direction and the wiring module 76 is provided on the second end surface of the capacitor module 68, the heat radiation path of the capacitor module 68 is provided. As a result, a path is formed from the first end surface and the second end surface of the capacitor module 68 to the end surface 72 and the tubular portion 71. That is, a path from the first end surface to the end surface 72 and a path from the second end surface to the tubular portion 71 are formed. As a result, in the capacitor module 68, heat can be radiated from the end surface portion other than the outer peripheral surface where the semiconductor module 66 is provided. That is, it is possible to dissipate heat not only in the radial direction but also in the axial direction.

Further, since the capacitor module 68 has a hollow cylindrical shape and the rotating shaft 11 is arranged in the inner peripheral portion thereof with a predetermined gap therebetween, the heat of the capacitor module 68 can be released from the hollow portion. ing. In this case, the rotation of the rotary shaft 11 causes a flow of air to enhance the cooling effect.

A disc-shaped control board 67 is attached to the wiring module 76. The control board 67 has a printed circuit board (PCB) on which a predetermined wiring pattern is formed, and a control device 77 corresponding to a control unit including various ICs and microcomputers is mounted on the board. There is. The control board 67 is fixed to the wiring module 76 by a fixing tool such as a screw. The control board 67 has an insertion hole 67a in the center thereof for inserting the rotary shaft 11.

The wiring module 76 has a first surface and a second surface that face each other in the axial direction, that is, face each other in the thickness direction. The first surface faces the capacitor module 68. The wiring module 76 is provided with the control board 67 on the second surface thereof. The bus bar 76c of the wiring module 76 extends from one side of the control board 67 to the other side. In such a configuration, the control board 67 may be provided with a notch for avoiding interference with the bus bar 76c. For example, a part of the outer edge of the circular control board 67 may be cut out.

As described above, according to the configuration in which the electric component 62 is housed in the space surrounded by the casing 64 and the housing 30, the rotor 40, and the stator 50 are provided in layers outside the electric component 62, the electric component 62 is generated in the inverter circuit. Electromagnetic noise is preferably shielded. That is, in the inverter circuit, it is conceivable that switching control is performed in each semiconductor module 66 using PWM control with a predetermined carrier frequency, and electromagnetic noise is generated by the switching control. It can be suitably shielded by the housing 30, the rotor 40, the stator 50, etc. on the radially outer side of 62.

Further, by disposing at least a part of the semiconductor module 66 in a region surrounded by the stator core 52 arranged radially outside of the tubular portion 71 of the casing 64, the semiconductor module 66 and the stator windings are disposed. Compared with the configuration in which 51 and 51 are arranged without interposing the stator core 52, even if magnetic flux is generated from the semiconductor module 66, the stator winding 51 is less likely to be affected. Further, even if magnetic flux is generated from the stator winding 51, the semiconductor module 66 is unlikely to be affected. It is more effective if the entire semiconductor module 66 is arranged in a region surrounded by the stator core 52 arranged radially outside the tubular portion 71 of the casing 64. Further, when at least a part of the semiconductor module 66 is surrounded by the cooling water passage 74, it is possible to obtain an effect that heat generated from the stator winding 51 and the magnet unit 42 does not easily reach the semiconductor module 66.

In the vicinity of the end plate 63 in the tubular portion 71, a through hole 78 for inserting a wiring member 79 (see FIG. 2) that electrically connects the outer stator 50 and the inner electric component 62 is formed. There is. As shown in FIG. 2, the wiring member 79 is connected to the end portion of the stator winding 51 and the bus bar 76c of the wiring module 76 by crimping, welding, or the like. The wiring member 79 is, for example, a bus bar, and the joint surface thereof is preferably flat and crushed. The through holes 78 may be provided at one place or a plurality of places, and in the present embodiment, the through holes 78 are provided at two places. With the configuration in which the through holes 78 are provided at two locations, the winding terminals extending from the two sets of three-phase windings can be easily connected by the wiring members 79, which is suitable for performing multi-phase connection. Has become.

As described above, in the housing 30, as shown in FIG. 4, the rotor 40 and the stator 50 are provided in order from the radial outside, and the inverter unit 60 is provided inside the stator 50 in the radial direction. Here, when the radius of the inner peripheral surface of the housing 30 is d, the rotor 40 and the stator 50 are arranged radially outside the distance d × 0.705 from the rotation center of the rotor 40. There is. In this case, a region of the rotor 40 and the stator 50 which is radially inward from the radially inner inner peripheral surface of the stator 50 (that is, the inner peripheral surface of the stator core 52) is the first region X1 in the radial direction. When the region between the inner peripheral surface of the stator 50 and the housing 30 is the second region X2, the cross-sectional area of the first region X1 is larger than the cross-sectional area of the second region X2. There is. Further, the volume of the first region X1 is larger than the volume of the second region X2 when viewed in a range where the magnet unit 42 of the rotor 40 and the stator winding 51 overlap in the radial direction.

When the rotor 40 and the stator 50 are magnetic circuit component assemblies, in the housing 30, the first region X <b> 1 radially inward from the inner peripheral surface of the magnetic circuit component assembly has a radial magnetic circuit component assembly. The volume is larger than that of the second region X2 between the inner peripheral surface and the housing 30.

Next, the configurations of the rotor 40 and the stator 50 will be described in more detail.

Generally, as a structure of a stator in a rotating electric machine, there is known one in which a plurality of slots are provided in a circumferential direction in a stator core made of laminated steel plates and having an annular shape, and a stator winding is wound in the slots. There is. Specifically, the stator core has a plurality of teeth extending in a radial direction from the yoke at predetermined intervals, and a slot is formed between the teeth adjacent to each other in the circumferential direction. Then, for example, a plurality of layers of conductor wires are accommodated in the slots in the radial direction, and the conductor wires form a stator winding.

However, in the above-described stator structure, when the stator winding is energized, magnetic saturation occurs in the teeth portion of the stator core as the magnetomotive force of the stator winding increases, which causes It is conceivable that the torque density will be limited. That is, in the stator core, it is considered that the magnetic flux occurs due to the rotating magnetic flux generated by the energization of the stator windings concentrated on the teeth.

Also, generally known is a configuration of an IPM (Interior Permanent Magnet) rotor in a rotating electric machine in which a permanent magnet is arranged on the d axis in the dq coordinate system and a rotor core is arranged on the q axis. In such a case, by exciting the stator winding near the d-axis, an exciting magnetic flux flows from the stator to the q-axis of the rotor according to Fleming's law. It is considered that this causes a wide range of magnetic saturation in the q-axis core portion of the rotor.

FIG. 7 is a torque diagram showing the relationship between the ampere-turn [AT] indicating the magnetomotive force of the stator winding and the torque density [Nm / L]. The broken line shows the characteristic of a general IPM rotor type rotating electric machine. As shown in FIG. 7, in a general rotating electric machine, by increasing the magnetomotive force in the stator, magnetic saturation occurs at two places, the tooth portion between the slots and the q-axis core portion. The increase in torque is limited. As described above, in the general rotary electric machine, the ampere-turn design value is limited by A1.

Therefore, in the present embodiment, in order to eliminate the limitation caused by magnetic saturation, the rotating electric machine 10 is provided with the following configuration. That is, as a first measure, in order to eliminate magnetic saturation generated in the stator core teeth in the stator, a slotless structure is adopted in the stator 50, and magnetic saturation generated in the q-axis core portion of the IPM rotor is eliminated. , SPM (Surface Permanent Magnet) rotors are used. According to the first device, it is possible to eliminate the above-mentioned two portions where magnetic saturation occurs, but it is considered that the torque in the low current region decreases (see the alternate long and short dash line in FIG. 7). Therefore, as a second measure, in order to recover the torque reduction by increasing the magnetic flux of the SPM rotor, a polar anisotropic structure in which the magnet magnetic path is lengthened in the magnet unit 42 of the rotor 40 to increase the magnetic force is adopted. ing.

Further, as a third device, a flat conductor structure in which the radial thickness of the stator 50 of the conductor wire is reduced in the coil side portion 53 of the stator winding 51 is adopted to recover the torque. Here, it is conceivable that a larger eddy current is generated in the stator winding 51 facing the magnet unit 42 due to the above-mentioned polar anisotropic structure with increased magnetic force. However, according to the third device, since the flat conductor structure is thin in the radial direction, it is possible to suppress the generation of radial eddy currents in the stator winding 51. As described above, according to each of the first to third configurations, as shown by the solid line in FIG. 7, while a magnet having a high magnetic force is adopted and the torque characteristic is expected to be significantly improved, the magnet having a high magnetic force is used. The concern about the generation of large eddy currents that can occur can be alleviated.

Furthermore, as a fourth measure, a magnet unit that uses a polar anisotropic structure and has a magnetic flux density distribution close to a sine wave is adopted. According to this, it is possible to increase the sinusoidal matching rate by the pulse control described later to enhance the torque, and eddy current loss (copper loss due to eddy current: eddy current loss) due to a more gentle change in magnetic flux than a radial magnet. ) Can also be further suppressed.

The sine wave matching rate will be explained below. The sine wave matching rate can be obtained by comparing the measured waveform of the surface magnetic flux density distribution measured by tracing the surface of the magnet with a magnetic flux probe and a sine wave having the same period and peak value. The amplitude of the primary waveform, which is the fundamental wave of the rotating electrical machine, corresponds to the sine wave matching rate, with respect to the amplitude of the actually measured waveform, that is, the amplitude of the fundamental wave plus other harmonic components. As the sine wave matching rate increases, the waveform of the surface magnetic flux density distribution approaches a sine wave shape. Then, when a primary sinusoidal current is supplied from the inverter to a rotating electric machine equipped with a magnet having an improved sinusoidal matching rate, the waveform of the surface magnetic flux density distribution of the magnet is close to a sinusoidal shape. It is possible to generate a large torque. The surface magnetic flux density distribution may be estimated by a method other than actual measurement, for example, electromagnetic field analysis using Maxwell's equation.

Also, as a fifth device, the stator winding 51 has a strand conductor structure in which a plurality of strands are gathered and bundled. According to this, since the strands are connected in parallel, a large current can flow and the generation of eddy currents generated in the conductor spread in the circumferential direction of the stator 50 in the flat conductor structure can be prevented from occurring. Is smaller, it can be more effectively suppressed than the case where the thickness is reduced in the radial direction by the third measure. Further, by arranging a plurality of strands twisted together, it is possible to cancel the eddy current with respect to the magnetic flux generated from the conductor by the right-handed screw law with respect to the magnetomotive force from the conductor.

In this way, by further adding the fourth device and the fifth device, the torque is increased while the magnet having a high magnetic force, which is the second device, is adopted and the eddy current loss due to the high magnetic force is suppressed. Can be planned.

Below, the slotless structure of the stator 50, the flat conductor structure of the stator winding 51, and the polar anisotropic structure of the magnet unit 42 described above will be individually described. Here, first, the slotless structure of the stator 50 and the flat conductor structure of the stator winding 51 will be described. 8 is a cross-sectional view of the rotor 40 and the stator 50, and FIG. 9 is an enlarged view of a part of the rotor 40 and the stator 50 shown in FIG. 10 is a cross-sectional view showing a cross section of the stator 50 taken along line XX of FIG. 11, and FIG. 11 is a cross-sectional view showing a vertical cross section of the stator 50. FIG. 12 is a perspective view of the stator winding 51. 8 and 9, the magnetizing direction of the magnet in the magnet unit 42 is indicated by an arrow.

As shown in FIGS. 8 to 11, the stator core 52 has a cylindrical shape in which a plurality of electromagnetic steel plates are laminated in the axial direction and has a predetermined thickness in the radial direction, and is on the rotor 40 side. The stator winding 51 is attached to the outside in the radial direction. In the stator core 52, the outer peripheral surface on the rotor 40 side is a conductor installation portion (conductor area). The outer peripheral surface of the stator core 52 has a curved surface shape without unevenness, and a plurality of conductor wire groups 81 are arranged on the outer peripheral surface at predetermined intervals in the circumferential direction. The stator core 52 functions as a back yoke that is a part of a magnetic circuit for rotating the rotor 40. In this case, a tooth (that is, an iron core) made of a soft magnetic material is not provided between each two conductive wire groups 81 that are adjacent in the circumferential direction (that is, a slotless structure). In the present embodiment, the resin material of the sealing member 57 is inserted into the gap 56 between the conductor wire groups 81. That is, in the stator 50, the inter-conductor member provided between the conductor groups 81 in the circumferential direction is configured as the sealing member 57 which is a non-magnetic material. Speaking of the state before the sealing of the sealing member 57, the conductor wire groups 81 are arranged on the outer side in the radial direction of the stator core 52 at predetermined intervals in the circumferential direction with a gap 56 which is an area between the conductor wires. Thus, the stator 50 having the slotless structure is constructed. In other words, each conductor wire group 81 is composed of two conductor wires 82, as will be described later, and a space between each two conductor wire groups 81 adjacent to each other in the circumferential direction of the stator 50 is occupied by only a non-magnetic material. There is. The non-magnetic material includes a non-magnetic gas such as air and a non-magnetic liquid in addition to the sealing member 57. In the following, the sealing member 57 is also referred to as a conductor-to-conductor member.

The configuration in which the teeth are provided between the conductor wire groups 81 arranged in the circumferential direction means that the teeth have a predetermined thickness in the radial direction and a predetermined width in the circumferential direction, so that the conductor wire groups are provided. It can be said that a part of the magnetic circuit, that is, a magnet magnetic path is formed between 81. In this respect, it can be said that the configuration in which the teeth are not provided between the conductive wire groups 81 is a configuration in which the above magnetic circuit is not formed.

As shown in FIG. 10, the stator winding (that is, armature winding) 51 has a predetermined thickness T2 (hereinafter, also referred to as first dimension) and width W2 (hereinafter, also referred to as second dimension). Has been formed. The thickness T2 is the shortest distance between the outer side surface and the inner side surface that face each other in the radial direction of the stator winding 51. The width W2 is fixed to function as one of the multiple phases of the stator winding 51 (three phases in the embodiment: three phases of U phase, V phase and W phase or three phases of X phase, Y phase and Z phase). It is the circumferential length of a part of the child winding 51 of the stator winding 51. Specifically, in FIG. 10, when two conductor groups 81 adjacent to each other in the circumferential direction function as one of three phases, for example, a U-phase, the two conductor groups 81 in the circumferential direction are end-to-end. Up to W2. The thickness T2 is smaller than the width W2.

Note that the thickness T2 is preferably smaller than the total width dimension of the two conductor wire groups 81 existing within the width W2. Further, if the cross-sectional shape of the stator winding 51 (more specifically, the conductive wire 82) is a perfect circle shape, an elliptical shape, or a polygonal shape, among the cross-sections of the conductive wire 82 along the radial direction of the stator 50, The maximum radial length of the stator 50 in the cross section may be W12, and the maximum circumferential length of the stator 50 in the cross section may be W11.

As shown in FIGS. 10 and 11, the stator winding 51 is sealed by a sealing member 57 made of a synthetic resin material as a sealing material (molding material). That is, the stator winding 51 is molded by the molding material together with the stator core 52. The resin can be regarded as Bs = 0 as a non-magnetic material or an equivalent of a non-magnetic material.

As seen from the cross section of FIG. 10, the sealing member 57 is provided between the conductor wire groups 81, that is, the gap 56 is filled with a synthetic resin material, and the sealing member 57 allows the space between the conductor wire groups 81. The insulating member is interposed in the structure. That is, the sealing member 57 functions as an insulating member in the gap 56. The sealing member 57 is on the outside in the radial direction of the stator core 52 in a range including all the conductor wire groups 81, that is, in a range in which the radial thickness dimension is larger than the radial thickness dimension of each conductor wire group 81. It is provided.

Further, when viewed in the vertical cross section of FIG. 11, the sealing member 57 is provided in a range including the turn portion 84 of the stator winding 51. Inside the stator winding 51 in the radial direction, the sealing member 57 is provided in a range including at least a part of the end faces of the stator core 52 that face each other in the axial direction. In this case, the stator winding 51 is resin-sealed at the end of each phase winding of each phase, that is, substantially the entire portion except the connection terminal with the inverter circuit.

In the configuration in which the sealing member 57 is provided in the range including the end surface of the stator core 52, the laminated steel plate of the stator core 52 can be pressed inward in the axial direction by the sealing member 57. Thereby, the laminated state of each steel plate can be maintained using the sealing member 57. Although the inner peripheral surface of the stator core 52 is not resin-sealed in the present embodiment, instead of this, the entire stator core 52 including the inner peripheral surface of the stator core 52 is resin-sealed. It may be configured.

When the rotary electric machine 10 is used as a vehicle power source, the sealing member 57 is made of highly heat-resistant fluororesin, epoxy resin, PPS resin, PEEK resin, LCP resin, silicon resin, PAI resin, PI resin, or the like. It is preferably configured. Considering the coefficient of linear expansion from the viewpoint of suppressing cracking due to the difference in expansion, it is desirable that the same material as the outer coating of the conductor wire of the stator winding 51 be used. That is, a silicon resin having a linear expansion coefficient that is generally twice or more that of another resin is preferably excluded. For electric appliances such as electric vehicles that do not have a combustion engine, PPO resin, phenol resin, and FRP resin having heat resistance of about 180 ° C. are also candidates. This is not the case in the field where the ambient temperature of the rotating electric machine can be considered to be less than 100 ° C.

The torque of the rotating electric machine 10 is proportional to the magnitude of magnetic flux. Here, when the stator core has teeth, the maximum magnetic flux amount in the stator is limited depending on the saturation magnetic flux density in the teeth, but the stator core does not have teeth. In that case, the maximum amount of magnetic flux at the stator is not limited. Therefore, the configuration is advantageous in increasing the current flowing through the stator winding 51 to increase the torque of the rotary electric machine 10.

In the present embodiment, the inductance of the stator 50 is reduced by using the structure without the teeth (slotless structure) in the stator 50. Specifically, the stator of a general rotating electric machine in which a conductor is housed in each slot partitioned by a plurality of teeth has an inductance of, for example, about 1 mH, whereas the stator 50 of the present embodiment has an inductance of about 1 mH. It is reduced to about 5 to 60 μH. In this embodiment, the mechanical time constant Tm can be reduced by reducing the inductance of the stator 50 while using the rotating electric machine 10 having the outer rotor structure. That is, it is possible to reduce the mechanical time constant Tm while increasing the torque. When the inertia is J, the inductance is L, the torque constant is Kt, and the back electromotive force constant is Ke, the mechanical time constant Tm is calculated by the following equation.
Tm = (J × L) / (Kt × Ke)
In this case, it can be confirmed that the reduction of the inductance L reduces the mechanical time constant Tm.

Each conductor wire group 81 on the outer side in the radial direction of the stator core 52 is configured by arranging a plurality of conductor wires 82 having a flat rectangular cross-section in the radial direction of the stator core 52. The conductors 82 are arranged in a direction of “diameter in the radial direction <dimension in the circumferential direction” in the cross section. As a result, the thickness of each conductor wire group 81 is reduced in the radial direction. In addition, the thickness of the conductor is reduced in the radial direction, and the conductor region extends flat to the region where the teeth have been in the past, thus forming a flat conductor region structure. As a result, the increase in the heat generation amount of the conductor, which is concerned that the cross-sectional area becomes small due to the thinning, is suppressed by flattening in the circumferential direction to increase the cross-sectional area of the conductor. Even with a configuration in which a plurality of conductors are arranged in the circumferential direction and connected in parallel, the conductor cross-sectional area is reduced by the conductor coating, but the same theory can be obtained. In addition, below, each of the conductor wire group 81 and each of the conductor wire 82 is also referred to as a conductive member.

Since there is no slot, in the stator winding 51 in the present embodiment, the conductor area occupied by the stator winding 51 in one round in the circumferential direction is designed to be larger than the conductor unoccupied area in which the stator winding 51 does not exist. be able to. In the conventional rotary electric machine for a vehicle, it is natural that the conductor region / conductor non-occupancy region in the circumferential direction of the stator winding is 1 or less. On the other hand, in the present embodiment, each conductor wire group 81 is provided such that the conductor region is equal to the conductor unoccupied region or the conductor region is larger than the conductor unoccupied region. Here, as shown in FIG. 10, when the conductor wire region in which the conductor wire 82 (that is, the straight line portion 83 described later) is arranged in the circumferential direction is WA and the inter-conductor wire region between adjacent conductor wires 82 is WB, the conductor wire is The area WA is larger than the inter-conductor area WB in the circumferential direction.

As a configuration of the conductor wire group 81 in the stator winding 51, the radial thickness dimension of the conductor wire group 81 is smaller than the circumferential width dimension of one phase in one magnetic pole. That is, in a configuration in which the conductor wire group 81 is composed of two layers of conductor wire 82 in the radial direction, and two conductor wire groups 81 are provided in one magnetic pole in the circumferential direction for each phase, the radial thickness of each conductor wire 82 is When Tc and the width of the conductor wire 82 in the circumferential direction are Wc, “Tc × 2 <Wc × 2” is satisfied. As another configuration, in a configuration in which the conductor wire group 81 is composed of two layers of conductor wire 82 and one conductor wire group 81 is provided in one magnetic pole in the circumferential direction for each phase, the relationship of “Tc × 2 <Wc” is satisfied. It is good to be constituted so that. In short, the conductor wire portions (conductor wire group 81) arranged in the stator winding 51 at predetermined intervals in the circumferential direction have a radial thickness dimension larger than a circumferential width dimension of one phase in one magnetic pole. It is small.

In other words, the thickness Tc in the radial direction of each conductor 82 is preferably smaller than the width Wc in the circumferential direction. Furthermore, the radial thickness dimension (2Tc) of the conductor wire group 81 including the two conductor wires 82 in the radial direction, that is, the radial thickness dimension (2Tc) of the conductor wire group 81 is smaller than the circumferential width dimension Wc. It should be small.

The torque of the rotating electric machine 10 is substantially inversely proportional to the radial thickness of the stator core 52 of the conductor wire group 81. In this respect, the thickness of the conductor wire group 81 is reduced on the outer side in the radial direction of the stator core 52, which is advantageous in increasing the torque of the rotary electric machine 10. The reason is that the magnetic resistance can be reduced by reducing the distance from the magnet unit 42 of the rotor 40 to the stator core 52 (that is, the distance of the portion without iron). According to this, the interlinkage magnetic flux of the stator core 52 by the permanent magnet can be increased, and the torque can be increased.

Further, by reducing the thickness of the conductor wire group 81, even if the magnetic flux leaks from the conductor wire group 81, it is easy to be collected in the stator core 52, and the magnetic flux leaks to the outside without being effectively used for improving the torque. Can be suppressed. That is, it is possible to suppress a decrease in magnetic force due to magnetic flux leakage, increase the interlinkage magnetic flux of the stator core 52 by the permanent magnet, and increase the torque.

The conductive wire 82 (conductor) is composed of a coated conductive wire in which the surface of a conductor body 82a is covered with an insulating coating 82b, and between the conductive wires 82 that overlap each other in the radial direction and between the conductive wire 82 and the stator core 52. Insulation is secured in each. The insulating coating 82b is formed of a coating if the wire 86 described later is a self-bonding coated wire, or an insulating member stacked separately from the coating of the wire 86. It should be noted that each phase winding formed of the conductor wire 82 retains the insulating property of the insulating coating 82b except for the exposed portion for connection. The exposed portion is, for example, an input / output terminal portion or a neutral point portion in the case of star connection. In the conductor wire group 81, the conductor wires 82 that are adjacent in the radial direction are fixed to each other by using resin fixing or self-bonding coated wire. As a result, dielectric breakdown, vibration, and sound due to the rubbing of the conductive wires 82 are suppressed.

In the present embodiment, the conductor 82a is configured as an assembly of a plurality of wires 86. Specifically, as shown in FIG. 13, the conductor 82a is formed in a twisted shape by twisting a plurality of element wires 86. Further, as shown in FIG. 14, the strands 86 are configured as a composite body in which thin fibrous conductive materials 87 are bundled. For example, the strand 86 is a composite of CNT (carbon nanotube) fibers, and as the CNT fibers, fibers containing boron-containing fine fibers in which at least a part of carbon is replaced with boron are used. As the carbon-based fine fiber, vapor-grown carbon fiber (VGCF) or the like can be used in addition to CNT fiber, but CNT fiber is preferably used. The surface of the wire 86 is covered with a polymer insulating layer such as enamel. Further, the surface of the wire 86 is preferably covered with a so-called enamel coating, which is made of a polyimide coating or an amideimide coating.

The conductor wire 82 constitutes an n-phase winding in the stator winding 51. The element wires 86 of the conductor wire 82 (that is, the conductor 82a) are adjacent to each other in contact with each other. The conductor wire 82 has a portion where the winding conductor is formed by twisting a plurality of element wires 86 in one or more positions in the phase, and the resistance value between the twisted element wires 86 is the element wire 86 itself. It is a wire assembly that is larger than the resistance value of. In other words, each two adjacent wires 86 have a first electrical resistivity in their adjacent direction and each of the wires 86 has a second electrical resistivity in its lengthwise direction. The rate is higher than the second electrical resistivity. The conductor wire 82 may be formed of a plurality of element wires 86, and the element wire assembly may cover the plurality of element wires 86 with an insulating member having a very high first electrical resistivity. Further, the conductor 82a of the conductor wire 82 is composed of a plurality of twisted element wires 86.

In the above conductor 82a, since a plurality of strands 86 are twisted together, the generation of eddy current in each strand 86 is suppressed, and the eddy current in the conductor 82a can be reduced. In addition, since each of the strands 86 is twisted, portions of the single strand 86 in which the magnetic field application directions are opposite to each other are generated, and the counter electromotive voltages are offset. Therefore, it is possible to reduce the eddy current. In particular, by configuring the wire 86 with the fibrous conductive material 87, it is possible to make the wire thinner and to increase the number of twists significantly, and it is possible to more appropriately reduce the eddy current.

The method of insulating the wires 86 from each other here is not limited to the polymer insulating film described above, and may be a method of making it difficult for a current to flow between the twisted wires 86 by utilizing contact resistance. That is, if the resistance value between the twisted wires 86 is larger than the resistance value of the wires 86 themselves, the above effect can be obtained due to the potential difference caused by the difference in resistance value. .. For example, by using the manufacturing equipment that creates the wire 86 and the manufacturing equipment that creates the stator 50 (armature) of the rotating electric machine 10 as separate discontinuous equipment, the wire length is reduced from the moving time and the work interval. 86 is oxidized, and the contact resistance can be increased, which is preferable.

As described above, the conductor wire 82 has a flat rectangular cross section and is arranged in a plurality in the radial direction. For example, a plurality of conductor wires covered with a self-bonding covered wire including a fusion bonding layer and an insulating layer. The strands 86 are assembled in a twisted state, and the fusion layers are fused to maintain the shape. In addition, the twisted wire without the fusion bonding layer or the wire of the self-bonding coated wire may be formed into a desired shape by molding with a synthetic resin or the like. If the thickness of the insulating coating 82b on the conductor wire 82 is, for example, 80 μm to 100 μm and is thicker than the coating thickness (5 to 40 μm) of a generally used conductor wire, insulation is provided between the conductor wire 82 and the stator core 52. Insulation between them can be secured without interposing paper or the like.

Moreover, it is desirable that the insulating coating 82b has a higher insulating performance than the insulating layer of the wire 86 and is configured to be able to insulate between the phases. For example, when the thickness of the polymer insulating layer of the wire 86 is, for example, about 5 μm, the thickness of the insulating coating 82b of the conducting wire 82 is set to about 80 μm to 100 μm so that insulation between phases can be preferably performed. Is desirable.

The conductor wire 82 may have a configuration in which a plurality of element wires 86 are bundled without being twisted. That is, the conductor wire 82 has a configuration in which a plurality of element wires 86 are twisted in its entire length, a configuration in which a plurality of element wires 86 are twisted in a part of its entire length, and a plurality of element wires 86 are twisted in its entire length. It may be any of the configurations that are bundled together. In summary, each conductor wire 82 forming the conductor wire portion is composed of a plurality of element wires 86 bundled together, and a resistance value between the bundled element wires is larger than the resistance value of the element wire 86 itself. Is becoming

Each conductive wire 82 is formed by bending so as to be arranged in a predetermined arrangement pattern in the circumferential direction of the stator winding 51, and thus a phase winding for each phase is formed as the stator winding 51. .. As shown in FIG. 12, in the stator winding 51, a coil side portion 53 is formed by a straight line portion 83 of each conductive wire 82 that extends linearly in the axial direction, and is located outside both sides of the coil side portion 53 in the axial direction. Coil ends 54 and 55 are formed by the protruding turn portion 84. Each of the conducting wires 82 is configured as a series of corrugated conducting wires by alternately repeating the straight portions 83 and the turn portions 84. The straight line portions 83 are arranged at positions radially opposite to the magnet unit 42, and the in-phase straight line portions 83 arranged at predetermined intervals at positions on the outer side in the axial direction of the magnet unit 42, The turn portions 84 are connected to each other. The straight line portion 83 corresponds to the “magnet facing portion”.

In the present embodiment, the stator winding 51 is formed into an annular shape by distributed winding. In this case, in the coil side portion 53, the linear portions 83 are arranged in the circumferential direction at intervals corresponding to one pole pair of the magnet unit 42 for each phase, and in the coil ends 54 and 55, the linear portions 83 for each phase are arranged. , Are connected to each other by a turn portion 84 formed in a substantially V shape. The respective straight line portions 83 forming a pair corresponding to one pole pair have current directions opposite to each other. Further, the one coil end 54 and the other coil end 55 are different in the combination of the pair of straight line portions 83 connected by the turn portion 84, and the connection at the coil ends 54, 55 is in the circumferential direction. By repeating this, the stator winding 51 is formed into a substantially cylindrical shape.

More specifically, the stator winding 51 forms a winding for each phase by using two pairs of conductor wires 82 for each phase, and one of the three windings (U Phase, V phase, W phase) and the other three-phase winding (X phase, Y phase, Z phase) are provided in two layers inside and outside in the radial direction. In this case, assuming that the number of phases of the stator winding 51 is S (6 in the case of the embodiment) and the number per phase of the conductor wire 82 is m, 2 × S × m = 2Sm conductor wires are provided for each pole pair. 82 will be formed. In the present embodiment, the number of phases S is 6, the number m is 4, and the rotating electric machine has 8 pole pairs (16 poles). Therefore, the 6 × 4 × 8 = 192 conductor wires 82 surround the stator core 52. Are arranged in the direction.

In the stator winding 51 shown in FIG. 12, in the coil side portion 53, the linear portions 83 are arranged so as to overlap each other in two layers that are adjacent in the radial direction, and in the coil ends 54 and 55, the linear portions that overlap in the radial direction are arranged. The turn portions 84 extend in the circumferential direction from 83 in the directions opposite to each other in the circumferential direction. That is, in the conductor wires 82 that are adjacent to each other in the radial direction, the directions of the turn portions 84 are opposite to each other except for the end portion of the stator winding 51.

Here, the winding structure of the conductor wire 82 in the stator winding 51 will be specifically described. In the present embodiment, a plurality of conducting wires 82 formed by wave winding are provided so as to be overlapped with a plurality of layers (for example, two layers) adjacent to each other in the radial direction. FIGS. 15A and 15B are views showing the form of each conductor wire 82 in the n-th layer, and FIG. 15A shows the conductor wire 82 as seen from the side of the stator winding 51. FIG. 15B shows the shape of the conductor wire 82 as viewed from one side in the axial direction of the stator winding 51. 15 (a) and 15 (b), the positions where the conductor wire group 81 is arranged are shown as D1, D2, D3 ,. Further, for convenience of explanation, only three conductors 82 are shown, which are referred to as a first conductor 82_A, a second conductor 82_B, and a third conductor 82_C.

In each of the conducting wires 82_A to 82_C, the straight line portions 83 are arranged at the position of the n-th layer, that is, at the same position in the radial direction, and the straight line portions 83 are separated by 6 positions (3 × m pairs) in the circumferential direction. The turn portions 84 are connected to each other. In other words, in each of the conductors 82_A to 82_C, on both ends of the seven straight line portions 83 arranged adjacent to each other in the circumferential direction of the stator winding 51 on the same circle centered on the axial center of the rotor 40. The two are connected to each other by one turn portion 84. For example, in the first conducting wire 82_A, a pair of straight line portions 83 are arranged at D1 and D7, respectively, and the pair of straight line portions 83 are connected by an inverted V-shaped turn portion 84. In addition, the other conductive wires 82_B and 82_C are arranged in the same n-th layer by shifting the positions in the circumferential direction one by one. In this case, since the conductors 82_A to 82_C are all arranged in the same layer, it is considered that the turn portions 84 interfere with each other. Therefore, in the present embodiment, an interference avoiding portion is formed in the turn portion 84 of each of the conductive wires 82_A to 82_C by offsetting a part thereof in the radial direction.

Specifically, the turn portion 84 of each of the conductive wires 82_A to 82_C is one inclined portion 84a that is a portion that extends in the circumferential direction on the same circle (first circle), and the same circle from the inclined portion 84a. Is also shifted radially inward (upward in FIG. 15B) to reach another circle (second circle), from the top 84b, the inclined portion 84c extending in the circumferential direction on the second circle, and the first circle. And a return portion 84d returning to the second circle. The top portion 84b, the inclined portion 84c, and the return portion 84d correspond to the interference avoiding portion. The inclined portion 84c may be configured to shift radially outward with respect to the inclined portion 84a.

That is, the turn portion 84 of each of the conductive wires 82_A to 82_C has the inclined portion 84a on one side and the inclined portion 84c on the other side on both sides of the apex portion 84b which is the center position in the circumferential direction, and these. The radial positions of the inclined portions 84a and 84c (the positions in the front-back direction of the paper in FIG. 15A and the positions in the vertical direction in FIG. 15B) are different from each other. For example, the turn portion 84 of the first conductive wire 82_A extends along the circumferential direction starting from the D1 position of the n-layer, and bends in the radial direction (for example, the radial inner side) at the top portion 84b that is the central position in the circumferential direction, By bending again in the circumferential direction, it extends along the circumferential direction again, and by bending again in the return portion 84d in the radial direction (for example, the radial outside), it reaches the D7 position of the n layer which is the end point position. There is.

According to the above configuration, in the conducting wires 82_A to 82_C, the inclined portions 84a on one side are arranged in the order of the first conducting wire 82_A → the second conducting wire 82_B → the third conducting wire 82_C from the top and the conducting wires 82_A ～ at the top portion 84b. The upper and lower sides of 82_C are interchanged, and the other inclined portions 84c are arranged in the order of the third conductor 82_C → the second conductor 82_B → the first conductor 82_A from the top. Therefore, the conductors 82_A to 82_C can be arranged in the circumferential direction without interfering with each other.

Here, in a configuration in which a plurality of conducting wires 82 are radially overlapped to form a conducting wire group 81, a turn portion 84 connected to a radially inner linear portion 83 of the plurality of layers of linear portions 83 and a radially outer portion It is preferable that the turn portion 84 connected to the straight line portion 83 and the turn portion 84 that are connected to the straight line portion 83 are arranged farther in the radial direction than the straight line portions 83. Further, in the case where the conductor wires 82 of a plurality of layers are bent to the same side in the radial direction near the end portion of the turn portion 84, that is, the boundary portion with the straight line portion 83, insulation is provided by interference between the conductor wires 82 of the adjacent layers. Should not be damaged.

For example, in D7 to D9 of FIGS. 15 (a) and 15 (b), the conductive wires 82 overlapping in the radial direction are respectively bent in the return portion 84d of the turn portion 84 in the radial direction. In this case, as shown in FIG. 16, the radius of curvature of the bent portion may be different between the conductor wire 82 of the nth layer and the conductor wire 82 of the (n + 1) th layer. Specifically, the radius of curvature R1 of the conductor wire 82 on the radially inner side (nth layer) is made smaller than the radius of curvature R2 of the conductor wire 82 on the radially outer side (n + 1th layer).

Also, the amount of shift in the radial direction may be different between the conductor wire 82 of the nth layer and the conductor wire 82 of the n + 1th layer. Specifically, the shift amount S1 of the conductor wire 82 on the radially inner side (nth layer) is made larger than the shift amount S2 of the conductor wire 82 on the radially outer side (n + 1th layer).

With the above configuration, mutual interference between the conductors 82 can be preferably avoided even when the conductors 82 overlapping in the radial direction are bent in the same direction. As a result, good insulation can be obtained.

Next, the structure of the magnet unit 42 in the rotor 40 will be described. In this embodiment, it is assumed that the magnet unit 42 is made of a permanent magnet and has a residual magnetic flux density Br = 1.0 [T] and an intrinsic coercive force Hcj = 400 [kA / m] or more. In short, the permanent magnet used in the present embodiment is a sintered magnet obtained by sintering a granular magnetic material and molding and solidifying it, and the intrinsic coercive force Hcj on the JH curve is 400 [kA / m] or more. The residual magnetic flux density Br is 1.0 [T] or more. When 5000 to 10000 [AT] is applied by the interphase excitation, the magnetic length of one pole pair, that is, the N pole and the S pole, in other words, the magnetic flux between the N pole and the S pole passes through the magnet. If a permanent magnet with a length of 25 [mm] is used, Hcj = 10000 [A], which indicates that demagnetization is not performed.

In other words, in the magnet unit 42, the saturation magnetic flux density Js is 1.2 [T] or more, the crystal grain size is 10 [μm] or less, and Js × α is 1 when the orientation rate is α. It is more than 0.0 [T].

A supplementary explanation about the magnet unit 42 is given below. The magnet unit 42 (magnet) is characterized by 2.15 [T] ≧ Js ≧ 1.2 [T]. In other words, examples of magnets used in the magnet unit 42 include NdFe11TiN, Nd2Fe14B, Sm2Fe17N3, and FeNi magnets having L10 type crystals. In addition, SmCo5, which is usually called Samacoba, FePt, Dy2Fe14B, CoPt, etc. cannot be used. Note that similar types of compounds, such as Dy2Fe14B and Nd2Fe14B, generally use dysprosium, which is a heavy rare earth element, while slightly losing the high Js characteristics of neodymium, but having a high coercive force of Dy. 2.15 [T] ≧ Js ≧ 1.2 [T] may be satisfied even in the case of a magnet having a magnet, and this case can also be adopted. In such a case, it is referred to as ([Nd1-xDyx] 2Fe14B). Furthermore, it is possible to achieve with two or more types of magnets having different compositions, for example, a magnet made of two or more types of materials such as FeNi plus Sm2Fe17N3. For example, Js = 1.6 [T] and Js It is also possible to achieve it by using a mixed magnet having an increased coercive force by mixing a small amount of Jd <1 [T], for example, Dy2Fe14B, into a magnet of Nd2Fe14B with a sufficient margin.

Further, in a rotating electric machine that is operated at a temperature outside the range of human activity, for example, 60 ° C. or higher, which exceeds the temperature of the desert, for example, in a motor application for a vehicle in which the temperature in the vehicle approaches 80 ° C. in summer, In particular, it is desirable to contain components such as FeNi and Sm2Fe17N3, which have a small temperature dependence coefficient. This is a temperature dependence coefficient in the motor operation from the temperature of -40 ° C in Northern Europe, which is within the range of human activity, to 60 ° C or more, which exceeds the desert temperature mentioned above, or to the heat resistant temperature of coil enamel coating of 180 to 240 ° C. This is because the motor characteristics differ greatly depending on the type, and it becomes difficult to perform optimal control with the same motor driver. When FeNi or Sm2Fe17N3 having the L10 type crystal is used, compared with Nd2Fe14B, the characteristic of possessing a temperature dependence coefficient of half or less can favorably reduce the load on the motor driver.

In addition, the magnet unit 42 is characterized in that the particle size in the fine powder state before orientation is 10 μm or less and the single magnetic domain particle diameter or more by using the above-mentioned magnet mixture. In a magnet, coercive force is increased by reducing the size of powder particles to the order of hundreds of nm, so in recent years, powder that has been made as small as possible has been used. However, if it is made too fine, the BH product of the magnet will drop due to oxidation or the like, so a single domain particle size or more is preferable. It is known that coercive force increases due to miniaturization if the particle size is up to a single domain particle size. The particle size described here is the particle size in the fine powder state during the orientation process, which is the manufacturing process of the magnet.

Further, each of the first magnet 91 and the second magnet 92 of the magnet unit 42 is a sintered magnet formed by so-called sintering, which is obtained by baking and hardening magnetic powder at a high temperature. In this sintering, the saturation magnetization Js of the magnet unit 42 is 1.2 T or more, the crystal grain size of the first magnet 91 and the second magnet 92 is 10 μm or less, and when the orientation rate is α, Js × α is It is performed so as to satisfy the condition of 1.0 T (tesla) or more. Each of the first magnet 91 and the second magnet 92 is sintered so as to satisfy the following conditions. And, since the orientation is performed in the orientation process in the manufacturing process, unlike the definition of the magnetic force direction in the magnetizing process of the isotropic magnet, it has an orientation ratio. The saturation magnetization Js of the magnet unit 42 of the present embodiment is 1.2 T or more, and the orientation ratio α of the first magnet 91 and the second magnet 92 is high so that Jr ≧ Js × α ≧ 1.0 [T]. The orientation rate is set. In addition, the orientation rate α referred to here is, for example, in each of the first magnet 91 or the second magnet 92, for example, there are six easy magnetization axes, five of which are oriented in the same direction A10 and the remaining one is If one of them faces the direction B10 that is tilted by 90 degrees with respect to the direction A10, α = 5/6, and if the other one faces the direction B10 that is tilted by 45 degrees with respect to the direction A10, the remaining Since the component that faces one direction A10 of cos is 45 ° = 0.707, α = (5 + 0.707) / 6. Although the first magnet 91 and the second magnet 92 are formed by sintering in this embodiment, the first magnet 91 and the second magnet 92 may be formed by another method as long as the above conditions are satisfied. .. For example, a method of forming an MQ3 magnet or the like can be adopted.

In the present embodiment, since the permanent magnet whose easy axis of magnetization is controlled by the orientation is used, the magnetic circuit length inside the magnet is the same as the magnetic circuit length of the linearly oriented magnet which conventionally produces 1.0 [T] or more. In comparison, it can be made longer. That is, the magnetic circuit length per pole pair can be achieved with a small amount of magnets, and the reversible demagnetization range can be maintained even when exposed to harsh high heat conditions as compared with the conventional design using linearly oriented magnets. You can In addition, the present inventor has found a configuration in which characteristics similar to those of a polar anisotropic magnet can be obtained even when using a conventional magnet.

The easy axis of magnetization refers to the crystal orientation that is easily magnetized in the magnet. The direction of the easy axis of magnetization of the magnet is a direction in which the orientation rate indicating the degree of alignment of the easy axis of magnetization is 50% or more, or the direction of the average orientation of the magnet.

As shown in FIGS. 8 and 9, the magnet unit 42 has an annular shape, and is provided inside the magnet holder 41 (specifically, inside the cylindrical portion 43 in the radial direction). The magnet unit 42 has a first magnet 91 and a second magnet 92 that are polar anisotropic magnets and have polarities different from each other. The first magnets 91 and the second magnets 92 are alternately arranged in the circumferential direction. The first magnet 91 is a magnet that forms an N pole in a portion near the stator winding 51, and the second magnet 92 is a magnet that forms an S pole in a portion near the stator winding 51. The 1st magnet 91 and the 2nd magnet 92 are permanent magnets which consist of rare earth magnets, such as a neodymium magnet, for example.

In each of the magnets 91 and 92, as shown in FIG. 9, a d-axis (direct-axis) which is the magnetic pole center and a magnetic pole boundary between the N pole and the S pole in a known dq coordinate system (in other words, magnetic flux density Is 0 Tesla) and the magnetization direction extends in an arc shape between the q-axis and the quadrature-axis. In each of the magnets 91 and 92, the magnetizing direction on the d-axis side is the radial direction of the annular magnet unit 42, and the magnetizing direction on the q-axis side is the circumferential direction of the annular magnet unit 42. The details will be described below. As shown in FIG. 9, each of the magnets 91 and 92 has a first portion 250 and two second portions 260 located on both sides of the first portion 250 in the circumferential direction of the magnet unit 42. In other words, the first portion 250 is closer to the d-axis than the second portion 260, and the second portion 260 is closer to the q-axis than the first portion 250. The magnet unit 42 is configured such that the direction of the easy axis 300 of the first portion 250 is more parallel to the d-axis than the direction of the easy axis 310 of the second portion 260. In other words, the magnet unit 42 is configured such that the angle θ11 formed by the easy magnetization axis 300 of the first portion 250 and the d axis is smaller than the angle θ12 formed by the easy magnetization axis 310 of the second portion 260 and the q axis. There is.

More specifically, the angle θ11 is an angle formed by the d axis and the easy magnetization axis 300 when the direction from the stator 50 (armature) to the magnet unit 42 is positive on the d axis. The angle θ12 is an angle formed by the q axis and the easy axis of magnetization 310 when the direction from the stator 50 (armature) to the magnet unit 42 in the q axis is positive. Both the angle θ11 and the angle θ12 are 90 ° or less in this embodiment. Each of the easy axes 300 and 310 here is defined as follows. In each part of the magnets 91 and 92, if one easy axis of magnetization is oriented in the direction A11 and the other easy axis of magnetization is oriented in the direction B11, the cosine of the angle θ formed by the direction A11 and the direction B11 is obtained. The absolute value (| cos θ |) is defined as the easy magnetization axis 300 or the easy magnetization axis 310.

That is, in each of the magnets 91 and 92, the direction of the easy magnetization axis is different between the d-axis side (portion near the d-axis) and the q-axis side (portion near the q-axis), and the magnetization on the d-axis side is different. The direction of the easy axis is close to the direction parallel to the d-axis, and on the q-axis side, the direction of the easy magnetization axis is close to the direction orthogonal to the q-axis. An arc-shaped magnet magnetic path is formed according to the direction of the easy axis of magnetization. In each of the magnets 91 and 92, the easy axis of magnetization may be oriented parallel to the d axis on the d-axis side, and the direction of easy magnetization may be orthogonal to the q axis on the q-axis side.

In addition, in the magnets 91 and 92, the stator-side outer surface on the stator 50 side (lower side in FIG. 9) of the peripheral surfaces of the magnets 91 and 92 and the end surface on the q-axis side in the circumferential direction generate magnetic flux. It is a magnetic flux acting surface which is an inflow and outflow surface, and a magnet magnetic path is formed so as to connect these magnetic flux acting surfaces (an outer surface on the stator side and an end surface on the q-axis side).

In the magnet unit 42, since the magnetic flux flows in an arc shape between the adjacent N and S poles by the magnets 91 and 92, the magnet magnetic path is longer than that of a radial anisotropic magnet, for example. Therefore, as shown in FIG. 17, the magnetic flux density distribution is close to a sine wave. As a result, unlike the magnetic flux density distribution of the radial anisotropic magnet shown as a comparative example in FIG. 18, the magnetic flux can be concentrated on the center side of the magnetic poles, and the torque of the rotary electric machine 10 can be increased. In addition, it can be confirmed that the magnet unit 42 of the present embodiment has a difference in the magnetic flux density distribution as compared with the conventional Halbach array magnets. 17 and 18, the horizontal axis represents the electrical angle and the vertical axis represents the magnetic flux density. In FIGS. 17 and 18, 90 ° on the horizontal axis indicates the d axis (that is, the magnetic pole center), and 0 ° and 180 ° on the horizontal axis indicate the q axis.

That is, according to each of the magnets 91 and 92 having the above configuration, the magnetic flux of the magnet on the d-axis is strengthened and the change of the magnetic flux near the q-axis is suppressed. Thereby, the magnets 91 and 92 in which the change of the surface magnetic flux from the q-axis to the d-axis is gentle in each magnetic pole can be suitably realized.

The sine wave matching rate of the magnetic flux density distribution may be set to a value of 40% or more, for example. By doing so, the amount of magnetic flux in the central portion of the waveform can be reliably improved as compared with the case of using a radial oriented magnet or a parallel oriented magnet having a sine wave matching rate of about 30%. Further, if the sine wave matching rate is 60% or more, the amount of magnetic flux in the central portion of the waveform can be reliably improved as compared with the magnetic flux concentration array such as the Halbach array.

In the radial anisotropic magnet shown in FIG. 18, the magnetic flux density changes sharply near the q axis. The steeper the change in magnetic flux density, the greater the eddy current generated in the stator winding 51. Also, the magnetic flux changes sharply on the stator winding 51 side. On the other hand, in the present embodiment, the magnetic flux density distribution has a magnetic flux waveform close to a sine wave. Therefore, in the vicinity of the q axis, the change in magnetic flux density is smaller than the change in magnetic flux density of the radial anisotropic magnet. This can suppress the generation of eddy currents.

In the magnet unit 42, a magnetic flux is generated in the direction orthogonal to the magnetic flux acting surface 280 on the side of the stator 50 near the d axis of each magnet 91, 92 (that is, the magnetic pole center), and the magnetic flux acts on the side of the stator 50. The arc shape is such that the farther from the surface 280, the further from the d-axis. Further, the more the magnetic flux is orthogonal to the magnetic flux acting surface, the stronger the magnetic flux becomes. In this respect, in the rotary electric machine 10 of the present embodiment, since each conductor wire group 81 is thinned in the radial direction as described above, the radial center position of the conductor wire group 81 approaches the magnetic flux acting surface of the magnet unit 42. The stator 50 can receive a strong magnetic flux from the rotor 40.

Further, the stator 50 is provided with a cylindrical stator core 52 on the radially inner side of the stator winding 51, that is, on the opposite side of the rotor 40 with the stator winding 51 interposed therebetween. Therefore, the magnetic flux extending from the magnetic flux acting surface of each magnet 91, 92 is attracted to the stator core 52 and circulates while using the stator core 52 as a part of the magnetic path. In this case, the direction and path of the magnet magnetic flux can be optimized.

Hereinafter, as a method of manufacturing the rotary electric machine 10, an assembly procedure for the bearing unit 20, the housing 30, the rotor 40, the stator 50, and the inverter unit 60 shown in FIG. 5 will be described. The inverter unit 60 has a unit base 61 and an electric component 62 as shown in FIG. 6, and each work process including a process of assembling the unit base 61 and the electric component 62 will be described. In the following description, the assembly including the stator 50 and the inverter unit 60 is the first unit, and the assembly including the bearing unit 20, the housing 30 and the rotor 40 is the second unit.

This manufacturing process is
A first step of mounting the electric component 62 on the inner side of the unit base 61 in the radial direction,
A second step of manufacturing the first unit by mounting the unit base 61 inside the stator 50 in the radial direction;
A third step of manufacturing the second unit by inserting the fixed portion 44 of the rotor 40 into the bearing unit 20 assembled in the housing 30,
A fourth step of mounting the first unit on the radially inner side of the second unit,
A fifth step of fastening and fixing the housing 30 and the unit base 61,
have. The order of performing these respective steps is: first step → second step → third step → fourth step → fifth step.

According to the above manufacturing method, the bearing unit 20, the housing 30, the rotor 40, the stator 50, and the inverter unit 60 are assembled as a plurality of assemblies (subassemblies), and then the assemblies are assembled together. Ease of handling and completion of inspection for each unit can be realized, and a rational assembly line can be constructed. Therefore, it is possible to easily cope with the production of various products.

In the first step, a good thermal conductor having good thermal conductivity is attached to at least one of the inner side of the unit base 61 in the radial direction and the outer side of the electric component 62 by coating or adhesion, and in that state, The electric component 62 may be attached to the unit base 61. As a result, the heat generated by the semiconductor module 66 can be effectively transmitted to the unit base 61.

In the third step, the rotor 40 may be inserted while maintaining the housing 30 and the rotor 40 coaxial with each other. Specifically, for example, the position of the outer peripheral surface of the rotor 40 (the outer peripheral surface of the magnet holder 41) or the inner peripheral surface of the rotor 40 (the inner peripheral surface of the magnet unit 42) is determined with reference to the inner peripheral surface of the housing 30. The housing 30 and the rotor 40 are assembled by using a jig and sliding either the housing 30 or the rotor 40 along the jig. As a result, it becomes possible to assemble heavy parts without applying an unbalanced load to the bearing unit 20, and the reliability of the bearing unit 20 is improved.

In the fourth step, it is recommended to assemble the first unit and the second unit while maintaining the same axis. Specifically, for example, a jig that determines the position of the inner peripheral surface of the unit base 61 with reference to the inner peripheral surface of the fixed portion 44 of the rotor 40 is used, and along the jig, the first unit and the second unit Assemble each of these units while sliding one of them. This makes it possible to assemble the rotor 40 and the stator 50 while preventing them from interfering with each other in a very small gap, so that the stator winding 51 may be damaged or the permanent magnet may be missing. It is possible to eliminate defective products.

It is also possible to set the order of each of the above steps to the second step → the third step → the fourth step → the fifth step → the first step. In this case, the delicate electric component 62 is assembled last, and the stress on the electric component 62 during the assembling process can be minimized.

Next, the configuration of the control system that controls the rotary electric machine 10 will be described. FIG. 19 is an electric circuit diagram of the control system of the rotary electric machine 10, and FIG. 20 is a functional block diagram showing control processing by the control device 110.

In FIG. 19, two sets of three-phase windings 51a and 51b are shown as the stator winding 51, and the three-phase winding 51a is composed of a U-phase winding, a V-phase winding and a W-phase winding. The phase winding 51b includes an X phase winding, a Y phase winding, and a Z phase winding. A first inverter 101 and a second inverter 102 corresponding to a power converter are provided for each of the three-phase windings 51a and 51b. Each of the inverters 101 and 102 is configured by a full bridge circuit having the same number of upper and lower arms as the number of phases of the phase winding, and by turning on / off a switch (semiconductor switching element) provided in each arm, The energizing current is adjusted in each phase winding.

A DC power supply 103 and a smoothing capacitor 104 are connected in parallel to each inverter 101, 102. The DC power supply 103 is composed of, for example, an assembled battery in which a plurality of unit cells are connected in series. Each switch of the inverters 101 and 102 corresponds to the semiconductor module 66 shown in FIG. 1 and the like, and the capacitor 104 corresponds to the capacitor module 68 shown in FIG.

The control device 110 includes a microcomputer including a CPU and various memories, and controls energization by turning on / off each switch in the inverters 101 and 102 based on various detection information of the rotating electric machine 10 and requests for power running drive and power generation. carry out. The control device 110 corresponds to the control device 77 shown in FIG. The detection information of the rotary electric machine 10 includes, for example, a rotation angle (electrical angle information) of the rotor 40 detected by an angle detector such as a resolver, a power supply voltage (inverter input voltage) detected by a voltage sensor, and a current sensor. The energizing current of each phase detected by is included. The control device 110 generates and outputs an operation signal for operating each switch of the inverters 101 and 102. The request for power generation is, for example, a request for regenerative driving when the rotary electric machine 10 is used as a vehicle power source.

The first inverter 101 includes a series connection body of the upper arm switch Sp and the lower arm switch Sn in each of the three phases including the U phase, the V phase, and the W phase. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive electrode terminal of the DC power supply 103, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative electrode terminal (ground) of the DC power supply 103. .. One ends of the U-phase winding, the V-phase winding, and the W-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. The respective phase windings are star-connected (Y connection), and the other ends of the respective phase windings are connected to each other at a neutral point.

The second inverter 102 has a configuration similar to that of the first inverter 101, and includes a series connection body of an upper arm switch Sp and a lower arm switch Sn in each of the three phases including the X phase, the Y phase, and the Z phase. ing. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive electrode terminal of the DC power supply 103, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative electrode terminal (ground) of the DC power supply 103. .. One ends of the X-phase winding, the Y-phase winding, and the Z-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. The respective phase windings are star-connected (Y connection), and the other ends of the respective phase windings are connected to each other at a neutral point.

FIG. 20 shows a current feedback control process for controlling the U, V, W phase currents and a current feedback control process for controlling the X, Y, Z phase currents. Here, first, the control processing on the U, V, W phase side will be described.

In FIG. 20, the current command value setting unit 111 uses a torque-dq map based on a power running torque command value or a power generation torque command value for the rotary electric machine 10 and an electrical angular velocity ω obtained by time differentiating the electrical angle θ. , D-axis current command value and q-axis current command value are set. The current command value setting unit 111 is commonly provided on the U, V, W phase side and the X, Y, Z phase side. The power generation torque command value is, for example, a regenerative torque command value when the rotary electric machine 10 is used as a vehicle power source.

The dq conversion unit 112 uses a current detection value (three phase currents) obtained by a current sensor provided for each phase as an orthogonal 2 with the direction of direction an axis of direction as the d axis. It is converted into a d-axis current and a q-axis current which are components of the dimensional rotational coordinate system.

The d-axis current feedback control unit 113 calculates the d-axis command voltage as an operation amount for feedback controlling the d-axis current to the d-axis current command value. Further, the q-axis current feedback control unit 114 calculates a q-axis command voltage as an operation amount for feedback controlling the q-axis current to a q-axis current command value. In each of these feedback control units 113 and 114, the command voltage is calculated using the PI feedback method based on the deviation of the d-axis current and the q-axis current from the current command value.

The three-phase conversion unit 115 converts the d-axis and q-axis command voltages into U-phase, V-phase, and W-phase command voltages. It should be noted that each of the above sections 111 to 115 is a feedback control section that performs feedback control of the fundamental wave current based on the dq conversion theory, and command voltages of the U phase, V phase, and W phase are feedback control values.

Then, the operation signal generation unit 116 uses the well-known triangular wave carrier comparison method to generate the operation signal of the first inverter 101 based on the three-phase command voltage. Specifically, the operation signal generation unit 116 performs the PWM control based on the magnitude comparison between the signal obtained by normalizing the command voltages of the three phases by the power supply voltage and the carrier signal such as the triangular wave signal, and thereby switches the upper and lower arms in each phase. An operation signal (duty signal) is generated.

Further, the X-, Y-, and Z-phase sides also have the same configuration, and the dq converter 122 determines the current detection value (three phase currents) by the current sensor provided for each phase in the field direction. It is converted into a d-axis current and a q-axis current, which are components of the orthogonal two-dimensional rotation coordinate system which is the d-axis.

The d-axis current feedback control unit 123 calculates the d-axis command voltage, and the q-axis current feedback control unit 124 calculates the q-axis command voltage. The three-phase conversion unit 125 converts the d-axis and q-axis command voltages into X-phase, Y-phase, and Z-phase command voltages. Then, the operation signal generation unit 126 generates the operation signal of the second inverter 102 based on the command voltages of the three phases. Specifically, the operation signal generation unit 126 switches the upper and lower arms in each phase by PWM control based on the magnitude comparison of a signal obtained by normalizing the command voltages of the three phases with the power supply voltage and a carrier signal such as a triangular wave signal. An operation signal (duty signal) is generated.

The driver 117 turns on / off the three-phase switches Sp and Sn in each of the inverters 101 and 102 based on the switch operation signals generated by the operation signal generation units 116 and 126.

Next, the torque feedback control process will be described. This process is mainly used for the purpose of increasing the output of the rotating electrical machine 10 and reducing the loss under operating conditions in which the output voltages of the inverters 101 and 102 increase, such as in the high rotation region and the high output region. The control device 110 selects and executes one of the torque feedback control process and the current feedback control process based on the operating conditions of the rotary electric machine 10.

FIG. 21 shows the torque feedback control processing corresponding to the U, V and W phases and the torque feedback control processing corresponding to the X, Y and Z phases. Note that, in FIG. 21, the same configurations as those in FIG. Here, first, the control processing on the U, V, W phase side will be described.

The voltage amplitude calculator 127 is a command value of the magnitude of the voltage vector based on the power running torque command value or the power generation torque command value for the rotary electric machine 10 and the electrical angular velocity ω obtained by time differentiating the electrical angle θ. Calculate the voltage amplitude command.

The torque estimation unit 128a calculates a torque estimation value corresponding to the U, V, and W phases based on the d-axis current and the q-axis current converted by the dq conversion unit 112. The torque estimation unit 128a may calculate the voltage amplitude command based on the map information in which the d-axis current, the q-axis current, and the voltage amplitude command are associated.

The torque feedback control unit 129a calculates a voltage phase command, which is a command value of the phase of the voltage vector, as an operation amount for feedback controlling the estimated torque value to the power running torque command value or the power generation torque command value. In the torque feedback control unit 129a, the voltage phase command is calculated using the PI feedback method based on the deviation of the estimated torque value with respect to the power running torque command value or the power generation torque command value.

The operation signal generation unit 130a generates an operation signal for the first inverter 101 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit 130a calculates a three-phase command voltage based on the voltage amplitude command, the voltage phase command, and the electrical angle θ, and standardizes the calculated three-phase command voltage with the power supply voltage. And PWM control based on the magnitude comparison with a carrier signal such as a triangular wave signal to generate switch operation signals for the upper and lower arms in each phase.

Incidentally, the operation signal generation unit 130a is based on the pulse amplitude information, the voltage phase instruction, the voltage phase instruction, the electrical angle θ, and pulse pattern information that is map information associated with the switch operation signal, the voltage amplitude instruction, the voltage phase instruction, and the electrical angle θ. Then, the switch operation signal may be generated.

Further, the X-, Y-, and Z-phase sides also have the same configuration, and the torque estimating unit 128b, based on the d-axis current and the q-axis current converted by the dq converting unit 122, the torque estimating unit 128b. The estimated torque value corresponding to the Z phase is calculated.

The torque feedback control unit 129b calculates a voltage phase command as an operation amount for feedback controlling the estimated torque value to the power running torque command value or the power generation torque command value. The torque feedback control unit 129b calculates the voltage phase command using the PI feedback method based on the deviation of the estimated torque value with respect to the power running torque command value or the power generation torque command value.

The operation signal generator 130b generates an operation signal for the second inverter 102 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit 130b calculates a three-phase command voltage based on the voltage amplitude command, the voltage phase command, and the electrical angle θ, and a signal obtained by normalizing the calculated three-phase command voltage with the power supply voltage. And PWM control based on the magnitude comparison with a carrier signal such as a triangular wave signal to generate switch operation signals for the upper and lower arms in each phase. The driver 117 turns on / off the three-phase switches Sp and Sn in the inverters 101 and 102 based on the switch operation signals generated by the operation signal generation units 130a and 130b.

By the way, the operation signal generation unit 130b is based on the pulse amplitude information, the voltage amplitude command, the voltage phase command, and the electrical angle θ that are map information in which the voltage amplitude command, the voltage phase command, the electrical angle θ, and the switch operation signal are related. Then, the switch operation signal may be generated.

By the way, in the rotary electric machine 10, there is a concern that the electrolytic corrosion of the bearings 21 and 22 may occur due to the generation of the shaft current. For example, when the energization of the stator winding 51 is switched by switching, the magnetic flux is distorted due to a minute shift in switching timing (switching imbalance), and as a result, the bearings 21, 22 supporting the rotating shaft 11 are generated. There is a concern that electrolytic corrosion will occur. The distortion of the magnetic flux is generated according to the inductance of the stator 50, and the electromotive voltage in the axial direction generated by the distortion of the magnetic flux causes dielectric breakdown in the bearings 21 and 22 and progresses electrolytic corrosion.

In this regard, in this embodiment, the following three measures are taken as measures against electrolytic corrosion. The first countermeasure against electrolytic corrosion is a countermeasure against electrolytic corrosion by reducing the inductance as the stator 50 is made coreless and by smoothing the magnetic flux of the magnet of the magnet unit 42. The second countermeasure against electrolytic corrosion is a countermeasure against electrolytic corrosion by using a cantilever structure with the bearings 21 and 22 for the rotating shaft. The third countermeasure against electrolytic corrosion is an electrolytic corrosion suppressing measure by molding the annular stator winding 51 together with the stator core 52 with a molding material. Below, the details of each of these measures will be explained individually.

First, in the first countermeasure against electrolytic corrosion, in the stator 50, the space between the conductor wire groups 81 in the circumferential direction is made teethless, and the conductor wire group 81 is sealed with a non-magnetic material instead of the teeth (iron core). The member 57 is provided (see FIG. 10). This makes it possible to reduce the inductance of the stator 50. By reducing the inductance in the stator 50, even if the switching timing shifts when the stator winding 51 is energized, the generation of magnetic flux distortion due to the switching timing shift is suppressed, and by extension the bearings 21 and 22. It is possible to suppress the electrolytic corrosion of. Note that the d-axis inductance is preferably equal to or less than the q-axis inductance.

Also, the magnets 91 and 92 are oriented such that the direction of the easy axis of magnetization is parallel to the d-axis on the d-axis side compared to the q-axis side (see FIG. 9). As a result, the magnet magnetic flux on the d-axis is strengthened, and the change in the surface magnetic flux (increase / decrease in magnetic flux) from the q-axis to the d-axis becomes gentle in each magnetic pole. Therefore, a rapid voltage change caused by the switching imbalance is suppressed, which in turn contributes to suppression of electrolytic corrosion.

As a second countermeasure against electrolytic corrosion, in the rotating electric machine 10, the bearings 21 and 22 are arranged so as to be offset to either the axial center of the rotor 40 in the axial direction (see FIG. 2). As a result, the influence of electrolytic corrosion can be reduced as compared with the configuration in which a plurality of bearings are provided on both sides of the rotor in the axial direction. In other words, in a configuration in which the rotor is supported by a plurality of bearings on both sides, a closed circuit that passes through the rotor, the stator, and each bearing (that is, each bearing on both sides in the axial direction with the rotor interposed) is generated as the high-frequency magnetic flux is generated. Formed, there is a concern that the shaft current may cause electrolytic corrosion of the bearing. On the other hand, in the configuration in which the rotor 40 is cantilevered by the plurality of bearings 21 and 22, the closed circuit is not formed and electrolytic corrosion of the bearings is suppressed.

Further, the rotary electric machine 10 has the following configuration in relation to the configuration for arranging the bearings 21 and 22 on one side. In the magnet holder 41, a contact avoidance portion that extends in the axial direction and avoids contact with the stator 50 is provided in the intermediate portion 45 that projects in the radial direction of the rotor 40 (see FIG. 2). In this case, when a closed circuit of the axial current is formed via the magnet holder 41, the closed circuit length can be increased to increase the circuit resistance. Thereby, the electrolytic corrosion of the bearings 21 and 22 can be suppressed.

The holding member 23 of the bearing unit 20 is fixed to the housing 30 on one side in the axial direction across the rotor 40, and the housing 30 and the unit base 61 (stator holder) are connected to each other on the other side. (See Figure 2). According to the present configuration, it is possible to preferably realize a configuration in which the bearings 21 and 22 are arranged eccentrically on one side in the axial direction of the rotating shaft 11. Further, in this configuration, since the unit base 61 is connected to the rotary shaft 11 via the housing 30, the unit base 61 can be arranged at a position electrically separated from the rotary shaft 11. It should be noted that if an insulating member such as resin is interposed between the unit base 61 and the housing 30, the unit base 61 and the rotary shaft 11 are electrically separated from each other. Thereby, the electrolytic corrosion of the bearings 21 and 22 can be suppressed appropriately.

In the rotary electric machine 10 of the present embodiment, the shaft voltage acting on the bearings 21 and 22 is reduced by the one-sided arrangement of the bearings 21 and 22 and the like. Further, the potential difference between the rotor 40 and the stator 50 is reduced. Therefore, the potential difference acting on the bearings 21 and 22 can be reduced without using conductive grease in the bearings 21 and 22. Since conductive grease generally contains fine particles such as carbon, it is considered that noise is generated. In this respect, in the present embodiment, the bearings 21 and 22 are configured to use non-conductive grease. Therefore, it is possible to suppress the inconvenience that noise is generated in the bearings 21 and 22. For example, when it is applied to an electric vehicle such as an electric vehicle, it is considered necessary to take noise countermeasures for the rotating electric machine 10, but the noise countermeasures can be suitably implemented.

In the third countermeasure against electrolytic corrosion, the stator winding 51 and the stator core 52 are molded with a molding material to suppress the positional deviation of the stator winding 51 in the stator 50 (see FIG. 11). ). In particular, in the rotating electric machine 10 of the present embodiment, since there is no inter-conductor member (teeth) between each conductor group 81 in the circumferential direction of the stator winding 51, there is a concern that the stator winding 51 may be displaced. Although conceivable, by molding the stator winding 51 together with the stator core 52, the displacement of the conductor wire position of the stator winding 51 is suppressed. Therefore, it is possible to suppress the distortion of the magnetic flux due to the positional deviation of the stator winding 51 and the occurrence of electrolytic corrosion of the bearings 21 and 22 due to the distortion.

Since the unit base 61 as a housing member for fixing the stator core 52 is made of carbon fiber reinforced plastic (CFRP), discharge to the unit base 61 is suppressed as compared with the case of being made of, for example, aluminum. As a result, it is possible to take suitable measures against electrolytic corrosion.

In addition, as a countermeasure against electrolytic corrosion of the bearings 21 and 22, it is possible to use a structure in which at least one of the outer ring 25 and the inner ring 26 is made of a ceramic material, or an insulating sleeve is provided outside the outer ring 25.

Below, other embodiments will be described focusing on the differences from the first embodiment.

(Second embodiment)
In this embodiment, the polar anisotropic structure of the magnet unit 42 in the rotor 40 is changed, which will be described in detail below.

As shown in FIGS. 22 and 23, the magnet unit 42 is configured using a magnet array called a Halbach array. That is, the magnet unit 42 has a first magnet 131 having a magnetization direction (direction of the magnetization vector) as a radial direction and a second magnet 132 having a magnetization direction (direction of the magnetization vector) as a circumferential direction, The first magnets 131 are arranged at predetermined intervals in the circumferential direction, and the second magnets 132 are arranged at positions between adjacent first magnets 131 in the circumferential direction. The 1st magnet 131 and the 2nd magnet 132 are permanent magnets which consist of rare earth magnets, such as a neodymium magnet, for example.

The first magnets 131 are arranged in the circumferential direction so as to be spaced apart from each other so that the poles on the side facing the stator 50 (radially inside) are alternately N poles and S poles. The second magnets 132 are arranged next to the first magnets 131 so that the polarities alternate in the circumferential direction. The cylindrical portion 43 provided so as to surround each of the magnets 131 and 132 may be a soft magnetic material core made of a soft magnetic material, and functions as a back core. The magnet unit 42 of the second embodiment also has the same relationship of the easy axis of magnetization with the d axis and the q axis in the dq coordinate system as in the first embodiment.

A magnetic body 133 made of a soft magnetic material is arranged on the outer side in the radial direction of the first magnet 131, that is, on the side of the cylindrical portion 43 of the magnet holder 41. For example, the magnetic body 133 may be made of an electromagnetic steel plate, soft iron, or a dust core material. In this case, the circumferential length of the magnetic body 133 is the same as the circumferential length of the first magnet 131 (in particular, the circumferential length of the outer peripheral portion of the first magnet 131). Further, the radial thickness of the first magnet 131 and the magnetic body 133 in the integrated state is the same as the radial thickness of the second magnet 132. In other words, the first magnet 131 is thinner than the second magnet 132 in the radial direction by the amount of the magnetic body 133. The magnets 131 and 132 and the magnetic body 133 are fixed to each other with an adhesive, for example. In the magnet unit 42, the outside in the radial direction of the first magnet 131 is the side opposite to the stator 50, and the magnetic body 133 is on the opposite side (counter side) to the stator 50 on both sides of the first magnet 131 in the radial direction. It is provided on the stator side).

A key 134 is formed on the outer peripheral portion of the magnetic body 133 as a convex portion that protrudes radially outward, that is, toward the cylindrical portion 43 side of the magnet holder 41. Further, on the inner peripheral surface of the cylindrical portion 43, a key groove 135 is formed as a recess for accommodating the key 134 of the magnetic body 133. The protruding shape of the key 134 and the groove shape of the key groove 135 are the same, and the same number of key grooves 135 as the keys 134 are formed corresponding to the keys 134 formed on each magnetic body 133. The engagement of the key 134 and the key groove 135 suppresses the positional deviation between the magnet holder 41 and the first magnet 131 and the second magnet 132 in the circumferential direction (rotational direction). The key 134 and the key groove 135 (the convex portion and the concave portion) may be provided on either the cylindrical portion 43 of the magnet holder 41 or the magnetic body 133, and conversely to the above, on the outer peripheral portion of the magnetic body 133. It is possible to provide the key groove 135 and the key 134 on the inner peripheral portion of the cylindrical portion 43 of the magnet holder 41.

Here, in the magnet unit 42, the magnetic flux density in the first magnet 131 can be increased by alternately arranging the first magnets 131 and the second magnets 132. Therefore, in the magnet unit 42, the magnetic flux can be concentrated on one side, and the magnetic flux can be strengthened on the side closer to the stator 50.

Further, by arranging the magnetic body 133 on the outer side in the radial direction of the first magnet 131, that is, on the side opposite to the stator, it is possible to suppress partial magnetic saturation on the outer side in the radial direction of the first magnet 131, which in turn causes the magnetic saturation. It is possible to suppress demagnetization of the first magnet 131 that occurs as a result. As a result, it is possible to increase the magnetic force of the magnet unit 42 as a result. The magnet unit 42 of the present embodiment has, so to speak, a configuration in which a portion of the first magnet 131, which is easily demagnetized, is replaced with the magnetic body 133.

24A and 24B are views specifically showing the flow of magnetic flux in the magnet unit 42, and FIG. 24A shows a conventional configuration in which the magnet unit 42 does not have the magnetic body 133. 24B shows the case where the configuration of the present embodiment having the magnetic body 133 in the magnet unit 42 is used. 24A and 24B, the cylindrical portion 43 of the magnet holder 41 and the magnet unit 42 are linearly developed, and the lower side of the figure is the stator side and the upper side is the anti-stator. It is on the side.

In the configuration of FIG. 24A, the magnetic flux acting surface of the first magnet 131 and the side surface of the second magnet 132 are in contact with the inner peripheral surface of the cylindrical portion 43, respectively. The magnetic flux acting surface of the second magnet 132 is in contact with the side surface of the first magnet 131. In this case, in the cylindrical portion 43, the magnetic flux F1 that enters the contact surface with the first magnet 131 through the outer path of the second magnet 132 and the magnetic flux F2 of the second magnet 132 that is substantially parallel to the cylindrical portion 43. A synthetic magnetic flux with the attractive magnetic flux is generated. Therefore, there is a concern that magnetic saturation partially occurs in the cylindrical portion 43 near the contact surface between the first magnet 131 and the second magnet 132.

On the other hand, in the configuration of FIG. 24B, the magnetic body 133 is provided between the magnetic flux acting surface of the first magnet 131 and the inner peripheral surface of the cylindrical portion 43 on the side opposite to the stator 50 of the first magnet 131. Since the magnetic substance 133 is provided, the passage of the magnetic flux is allowed. Therefore, magnetic saturation in the cylindrical portion 43 can be suppressed, and the proof stress against demagnetization is improved.

Also, in the configuration of FIG. 24 (b), unlike in FIG. 24 (a), F2 that promotes magnetic saturation can be erased. Thereby, the permeance of the entire magnetic circuit can be effectively improved. With this configuration, the magnetic circuit characteristics can be maintained even under severe high heat conditions.

Also, compared to the radial magnet in the conventional SPM rotor, the magnet magnetic path that runs inside the magnet becomes longer. Therefore, the magnet permeance can be increased, the magnetic force can be increased, and the torque can be increased. Furthermore, since the magnetic flux concentrates at the center of the d-axis, the sine wave matching rate can be increased. In particular, if the current waveform is a sine wave or a trapezoidal wave by PWM control, or if a 120-degree energized switching IC is used, the torque can be enhanced more effectively.

When the stator core 52 is made of an electromagnetic steel plate, the radial thickness of the stator core 52 is preferably 1/2 or more than 1/2 of the radial thickness of the magnet unit 42. For example, the radial thickness of the stator core 52 may be ½ or more of the radial thickness of the first magnet 131 provided at the magnetic pole center of the magnet unit 42. The radial thickness of the stator core 52 is preferably smaller than the radial thickness of the magnet unit 42. In this case, since the magnetic flux of the magnet is about 1 [T] and the saturation magnetic flux density of the stator core 52 is 2 [T], the radial thickness of the stator core 52 is set to the radial thickness of the magnet unit 42. The magnetic flux leakage to the inner peripheral side of the stator core 52 can be prevented by setting the ratio to 1/2 or more.

▽ In the magnet of Halbach structure or polar anisotropic structure, the magnetic path is a pseudo arc shape, so that the magnetic flux can be increased in proportion to the thickness of the magnet that handles the magnetic flux in the circumferential direction. In such a configuration, it is considered that the magnetic flux flowing in the stator core 52 does not exceed the magnetic flux in the circumferential direction. That is, when using an iron-based metal having a saturation magnetic flux density of 2 [T] with respect to the magnetic flux of 1 [T] of the magnet, if the thickness of the stator core 52 is set to be at least half the magnet thickness, magnetic saturation will not occur, which is preferable. It is possible to provide a small and lightweight rotating electric machine. Here, since the demagnetizing field from the stator 50 acts on the magnet magnetic flux, the magnet magnetic flux is generally 0.9 [T] or less. Therefore, if the stator core has half the thickness of the magnet, its magnetic permeability can be suitably kept high.

Below, a modified example in which a part of the above-mentioned configuration is changed will be explained.

(Modification 1)
In the above-described embodiment, the outer peripheral surface of the stator core 52 is formed into a curved surface having no unevenness, and the plurality of conductor wire groups 81 are arranged on the outer peripheral surface at predetermined intervals, but this may be changed. For example, as shown in FIG. 25, the stator core 52 includes an annular yoke 141 provided on the opposite side of the stator winding 51 in the radial direction from the rotor 40 (lower side in the figure). From the yoke 141, there is a protrusion 142 that extends so as to protrude between the linear portions 83 that are adjacent in the circumferential direction. The protrusions 142 are provided radially outside the yoke 141, that is, on the rotor 40 side at predetermined intervals. Each conductor wire group 81 of the stator winding 51 is engaged with the protruding portion 142 in the circumferential direction, and is arranged side by side in the circumferential direction while using the protruding portion 142 as a positioning portion of the conductor wire group 81. The protrusion 142 corresponds to the “inter-conductor member”.

The protrusion 142 has a thickness in the radial direction from the yoke 141, in other words, as shown in FIG. 25, the protrusion 142 extends from the inner side surface 320 of the linear portion 83 adjacent to the yoke 141 in the radial direction of the yoke 141. The distance W to the apex is smaller than 1/2 (H1 in the figure) of the radial thickness dimension of the linear portion 83, which is adjacent to the yoke 141 in the radial direction, among the linear portions 83 in the plurality of layers inside and outside the radial direction. It is composed. In other words, the size (thickness) T1 (twice the thickness of the conductor wire 82) of the conductor wire group 81 (conductive member) in the radial direction of the stator winding 51 (stator core 52), in other words, the stator core of the conductor wire group 81. The non-magnetic member (sealing member 57) may occupy a range of 3/4 of the shortest distance between the surface 320 in contact with 52 and the surface 330 of the conductor wire group 81 facing the rotor 40. Due to the thickness limitation of the protrusions 142, the protrusions 142 do not function as teeth between the conductor wire groups 81 (that is, the straight portions 83) that are adjacent to each other in the circumferential direction, and magnetic paths are not formed by the teeth. .. The protrusions 142 may not be provided all between the conductor groups 81 arranged in the circumferential direction, but may be provided between at least one conductor group 81 adjacent in the circumferential direction. For example, the protrusions 142 may be provided at equal intervals in the circumferential direction for each predetermined number between the conductor wire groups 81. The shape of the protrusion 142 may be an arbitrary shape such as a rectangular shape or an arc shape.

The linear portion 83 may be provided as a single layer on the outer peripheral surface of the stator core 52. Therefore, in a broad sense, the thickness of the protrusion 142 in the radial direction from the yoke 141 may be smaller than 1/2 of the thickness of the straight portion 83 in the radial direction.

Assuming a virtual circle centered on the axis of the rotary shaft 11 and passing through the radial center position of the linear portion 83 radially adjacent to the yoke 141, the protrusion 142 is within the range of the virtual circle. It is preferable to have a shape that projects from the yoke 141, in other words, a shape that does not project radially outward of the virtual circle (that is, the rotor 40 side).

According to the above configuration, the protrusion 142 has a limited thickness in the radial direction, and does not function as a tooth between the linear portions 83 that are adjacent in the circumferential direction. It is possible to bring the adjacent straight line portions 83 closer to each other as compared with the case where is provided. As a result, the cross-sectional area of the conductor 82a can be increased, and heat generation due to the energization of the stator winding 51 can be reduced. With such a configuration, it is possible to eliminate magnetic saturation due to the absence of teeth, and it is possible to increase the energization current to the stator winding 51. In this case, it is possible to suitably cope with the increase in the amount of heat generated as the energizing current increases. Further, in the stator winding 51, since the turn portion 84 has the interference avoiding portion that is shifted in the radial direction and avoids interference with other turn portions 84, the different turn portions 84 are separated from each other in the radial direction. Can be placed. As a result, the heat dissipation of the turn portion 84 can be improved. As described above, the heat dissipation performance of the stator 50 can be optimized.

Further, if the yoke 141 of the stator core 52 and the magnet unit 42 of the rotor 40 (that is, the magnets 91 and 92) are separated by a predetermined distance or more, the radial thickness of the protrusion 142 is as shown in FIG. It's not bound to H1. Specifically, if the yoke 141 and the magnet unit 42 are separated by 2 mm or more, the radial thickness of the protrusion 142 may be H1 or more in FIG. For example, when the radial thickness of the linear portion 83 exceeds 2 mm and the conductor wire group 81 is composed of the two conductor wires 82 inside and outside the radial direction, the linear portion 83 not adjacent to the yoke 141, That is, the protrusion 142 may be provided in the range from the yoke 141 to the half position of the conductor wire 82 of the second layer. In this case, if the radial thickness of the protrusion 142 is up to “H1 × 3/2”, the effect can be obtained to some extent by increasing the conductor cross-sectional area of the conductor wire group 81.

Further, the stator core 52 may have the configuration shown in FIG. Although the sealing member 57 is omitted in FIG. 26, the sealing member 57 may be provided. In FIG. 26, for convenience, the magnet unit 42 and the stator core 52 are linearly expanded and shown.

In the configuration of FIG. 26, the stator 50 has the protrusions 142 as inter-conductor members between the conductors 82 (that is, the straight portions 83) adjacent to each other in the circumferential direction. When the stator winding 51 is energized, the stator 50 magnetically functions together with one of the magnetic poles (N pole or S pole) of the magnet unit 42 and forms a portion 350 extending in the circumferential direction of the stator 50. Have. Assuming that the length of the portion 350 in the circumferential direction of the stator 50 is Wn, the total width of the protrusions 142 existing in this length range Wn (that is, the total dimension of the stator 50 in the circumferential direction). When Wt is set, the saturation magnetic flux density of the protrusion 142 is Bs, the width dimension of one pole of the magnet unit 42 in the circumferential direction is Wm, and the residual magnetic flux density of the magnet unit 42 is Br, the protrusion 142 is
Wt × Bs ≦ Wm × Br (1)
It is made of a magnetic material.

Note that the range Wn is set so as to include a plurality of conductor wire groups 81 adjacent to each other in the circumferential direction and a plurality of conductor wire groups 81 whose excitation timings overlap. At this time, it is preferable to set the center of the gap 56 of the conductor wire group 81 as a reference (boundary) when setting the range Wn. For example, in the case of the configuration illustrated in FIG. 26, the fourth to the fourth conductor wire groups 81 in order from the shortest distance from the magnetic pole center of the N pole in the circumferential direction correspond to the plurality of conductor wire groups 81. Then, the range Wn is set so as to include the four conducting wire groups 81. At this time, the ends (starting point and ending point) of the range Wn are set as the center of the gap 56.

In FIG. 26, since the projections 142 are included in half at both ends of the range Wn, a total of four projections 142 are included in the range Wn. Therefore, assuming that the width of the protrusion 142 (that is, the dimension of the protrusion 142 in the circumferential direction of the stator 50, in other words, the interval between the adjacent conductor wire groups 81) is A, the total of the protrusions 142 included in the range Wn is calculated. The width is Wt = 1 / 2A + A + A + A + 1 / 2A = 4A.

Specifically, in the present embodiment, the three-phase winding of the stator winding 51 is distributed winding, and in the stator winding 51, one pole of the magnet unit 42 has the number of protrusions 142, that is, The number of gaps 56 between the conductor wire groups 81 is “the number of phases × Q”. Here, Q is the number of one-phase conductors 82 in contact with the stator core 52. When the conductor wire 82 is the conductor wire group 81 laminated in the radial direction of the rotor 40, it can be said that it is the number of the conductor wires 82 on the inner peripheral side of the one-phase conductor wire group 81. In this case, when the three-phase windings of the stator winding 51 are energized in a predetermined order for each phase, the protrusions 142 for two phases are excited within one pole. Therefore, the total width dimension Wt in the circumferential direction of the protrusion 142 that is excited by the energization of the stator winding 51 in the range of one pole of the magnet unit 42 is the width of the protrusion 142 (that is, the gap 56) in the circumferential direction. If the dimension is A, then the number of excited phases × Q × A = 2 × 2 × A.

Then, after the total width dimension Wt is defined in this way, the protrusion 142 in the stator core 52 is formed as a magnetic material that satisfies the relationship of (1) above. The total width dimension Wt is also the circumferential dimension of a portion where the relative magnetic permeability can be greater than 1 within one pole. Further, considering the allowance, the total width dimension Wt may be the circumferential width dimension of the protrusion 142 in one magnetic pole. Specifically, since the number of the protrusions 142 for one pole of the magnet unit 42 is “the number of phases × Q”, the circumferential width dimension (total width dimension Wt) of the protrusions 142 for one magnetic pole is represented by “ The number of phases × Q × A = 3 × 2 × A = 6A ”.

Note that the distributed winding referred to here is one pole pair period (N pole and S pole) of the magnetic pole, and there is one pole pair of the stator winding 51. The one pole pair of the stator winding 51 mentioned here is composed of two straight portions 83 and a turn portion 84 in which currents flow in mutually opposite directions and are electrically connected by the turn portion 84. As long as the above conditions are met, even short-pitch winding (Short Pitch Winding) is considered to be an equivalent of full Pitch Winding distributed winding.

Next, an example of concentrated winding is shown. The term "concentrated winding" as used herein means that the width of one pole pair of magnetic poles is different from the width of one pole pair of the stator winding 51. As an example of concentrated winding, one conductor pair 81 is three for one magnetic pole pair, three conductor conductor groups 81 are two for two magnetic pole pairs, and nine conductor conductor groups 81 are for four magnetic pole pairs, 5 For example, there are nine conductor groups 81 for one magnetic pole pair.

Here, when the stator windings 51 are concentrated windings, when the three-phase windings of the stator windings 51 are energized in a predetermined order, the stator windings 51 for two phases are excited. As a result, the protrusions 142 for the two phases are excited. Therefore, the width Wt in the circumferential direction of the protrusion 142 excited by the energization of the stator winding 51 in the range of one pole of the magnet unit 42 is “A × 2”. In addition, the width dimension Wt is thus defined, and the protrusion 142 is formed of a magnetic material that satisfies the relationship of (1). In the case of the concentrated winding described above, the total width of the projections 142 in the circumferential direction of the stator 50 in the region surrounded by the same-phase conductor wire group 81 is A. Further, Wm in the concentrated winding corresponds to “entire circumference of a surface of the magnet unit 42 facing the air gap” × “number of phases” ÷ “dispersion number of the conductor wire group 81”.

By the way, for neodymium magnets, samarium-cobalt magnets, and ferrite magnets, which have a BH product of 20 [MGOe (kJ / m ^ 3)] or more, Bd = 1.0 or more [T], and iron Br = 2.0 or more [T]. ]. Therefore, as the high-power motor, the protrusion 142 in the stator core 52 may be any magnetic material that satisfies the relationship of Wt <1/2 × Wm.

Further, as will be described later, when the conductive wire 82 includes the outer layer coating 182, the conductive wire 82 may be arranged in the circumferential direction of the stator core 52 so that the outer coating films 182 of the conductive wires 82 come into contact with each other. In this case, Wt can be regarded as 0 or the thickness of the outer layer coating 182 of both conducting wires 82 in contact with each other.

25 and 26 are configured to have inter-conductor members (protrusions 142) that are disproportionately small with respect to the magnet magnetic flux on the rotor 40 side. The rotor 40 is a flat surface magnet type rotor having a low inductance and a magnetic resistance having no saliency. With such a configuration, it is possible to reduce the inductance of the stator 50, suppress the occurrence of magnetic flux distortion due to the deviation of the switching timing of the stator winding 51, and thus suppress the electrolytic corrosion of the bearings 21 and 22. ..

(Modification 2)
It is also possible to employ the following configuration as the stator 50 using the inter-conductor member that satisfies the relationship of the above formula (1). In FIG. 27, a toothed portion 143 is provided as an inter-conductor member on the outer peripheral surface side (upper surface side in the figure) of the stator core 52. The tooth portions 143 are provided at predetermined intervals in the circumferential direction so as to project from the yoke 141, and have the same thickness dimension as the conductor wire group 81 in the radial direction. The side surface of the toothed portion 143 is in contact with each conductor wire 82 of the conductor wire group 81. However, there may be a gap between the tooth-shaped portion 143 and each conductive wire 82.

The tooth-shaped portion 143 has a limited width in the circumferential direction, and is provided with pole teeth (stator teeth) that are disproportionately thin with respect to the amount of magnets. With this configuration, the tooth portion 143 is reliably saturated by the magnetic flux of the magnet at 1.8 T or more, and the inductance can be reduced due to the reduction of the permeance.

Here, in the magnet unit 42, when the surface area per pole of the magnetic flux acting surface on the stator side is Sm and the residual magnetic flux density of the magnet unit 42 is Br, the magnetic flux on the magnet unit side is, for example, “Sm × Br”. Become. Further, assuming that the surface area of each tooth portion 143 on the rotor side is St and the number of the conductor wire 82 per phase is m, the tooth winding portions 143 for two phases are excited in one pole by energizing the stator winding 51. If so, the magnetic flux on the stator side is, for example, “St × m × 2 × Bs”. in this case,
St × m × 2 × Bs <Sm × Br (2)
The inductance is reduced by limiting the size of the tooth-like portion 143 such that

When the magnet unit 42 and the toothed portion 143 have the same axial dimension, the circumferential width dimension of one pole of the magnet unit 42 is Wm, and the circumferential width dimension of the toothed portion 143 is Wst. Then, the above equation (2) is replaced by the equation (3).
Wst × m × 2 × Bs <Wm × Br (3)
More specifically, assuming that Bs = 2T, Br = 1T, and m = 2, for example, the above equation (3) has a relationship of “Wst <Wm / 8”. In this case, the inductance is reduced by making the width dimension Wst of the tooth-shaped portion 143 smaller than 1/8 of the width dimension Wm of one pole of the magnet unit 42. If the number m is 1, the width dimension Wst of the toothed portion 143 may be smaller than 1/4 of the width dimension Wm of one pole of the magnet unit 42.

In the above formula (3), “Wst × m × 2” is a circumferential width dimension of the toothed portion 143 excited by energization of the stator winding 51 in the range of one pole of the magnet unit 42. Equivalent to.

In the configuration of FIG. 27, similar to the configurations of FIGS. 25 and 26 described above, the configuration has an inter-conductor member (tooth portion 143) that is disproportionately small with respect to the magnet magnetic flux on the rotor 40 side. With such a configuration, it is possible to reduce the inductance of the stator 50, suppress the occurrence of magnetic flux distortion due to the deviation of the switching timing of the stator winding 51, and thus suppress the electrolytic corrosion of the bearings 21 and 22. ..

(Modification 3)
In the above-described embodiment, the sealing member 57 that covers the stator winding 51 is in a range including all the conductor wire groups 81 on the outer side in the radial direction of the stator core 52, that is, the radial thickness dimension is the diameter of each conductor wire group 81. Although it is configured to be provided in a range larger than the thickness dimension in the direction, this may be changed. For example, as shown in FIG. 28, the sealing member 57 may be provided so that a part of the conductor wire 82 protrudes. More specifically, the sealing member 57 is provided such that a part of the conductor wire 82, which is the radially outermost portion of the conductor wire group 81, is exposed radially outward, that is, on the stator 50 side. In this case, the radial thickness of the sealing member 57 is preferably the same as or smaller than the radial thickness of each conductor wire group 81.

(Modification 4)
As shown in FIG. 29, in the stator 50, each conductor wire group 81 may not be sealed by the sealing member 57. That is, the sealing member 57 that covers the stator winding 51 is not used. In this case, an inter-conductor member is not provided between the conductor groups 81 arranged in the circumferential direction, so that there is a gap. In short, the inter-conductor members are not provided between the conductor groups 81 arranged in the circumferential direction. Note that air may be regarded as Bs = 0 as a non-magnetic substance or an equivalent of a non-magnetic substance, and the air may be arranged in this gap.

(Modification 5)
When the inter-conductor member of the stator 50 is made of a non-magnetic material, it is possible to use a material other than resin as the non-magnetic material. For example, a metallic non-magnetic material such as SUS304 which is austenitic stainless steel may be used.

(Modification 6)
The stator 50 may not have the stator core 52. In this case, the stator 50 is composed of the stator winding 51 shown in FIG. In the stator 50 not including the stator core 52, the stator winding 51 may be sealed with a sealing material. Alternatively, the stator 50 may include an annular winding holder made of a non-magnetic material such as synthetic resin, instead of the stator core 52 made of a soft magnetic material.

(Modification 7)
In the first embodiment described above, a plurality of magnets 91 and 92 arranged in the circumferential direction are used as the magnet unit 42 of the rotor 40. However, this is changed, and the magnet unit 42 is an annular permanent magnet. A configuration using a magnet may be used. Specifically, as shown in FIG. 30, an annular magnet 95 is fixed inside the cylindrical portion 43 of the magnet holder 41 in the radial direction. The annular magnet 95 is provided with a plurality of magnetic poles whose polarities alternate in the circumferential direction, and the magnets are integrally formed on both the d-axis and the q-axis. The annular magnet 95 is formed with an arc-shaped magnet magnetic path in which the orientation of the magnetic poles in the d-axis is the radial direction and the orientation of the q-axis between the magnetic poles is the circumferential direction.

In the annular magnet 95, the easy magnetization axis is parallel to or close to the d axis in the portion near the d axis, and the easy magnetization axis is orthogonal to the q axis or in the q axis in the portion near the q axis. It suffices that the orientation is such that an arc-shaped magnet magnetic path that is oriented almost orthogonally is formed.

(Modification 8)
In this modification, a part of the control method of the control device 110 is changed. In this modification, differences from the configuration described in the first embodiment will be mainly described.

First, the processing in the operation signal generation units 116 and 126 shown in FIG. 20 and the operation signal generation units 130a and 130b shown in FIG. 21 will be described with reference to FIG. The processing in each operation signal generation unit 116, 126, 130a, 130b is basically the same. Therefore, the processing of the operation signal generation unit 116 will be described below as an example.

The operation signal generation unit 116 includes a carrier generation unit 116a and U, V, W phase comparators 116bU, 116bV, 116bW. In the present embodiment, the carrier generation unit 116a generates and outputs a triangular wave signal as the carrier signal SigC.

The carrier signal SigC generated by the carrier generation unit 116a and the U, V, W phase command voltages calculated by the three-phase conversion unit 115 are input to the U, V, W phase comparators 116bU, 116bV, 116bW. It The U-, V-, and W-phase command voltages have, for example, sinusoidal waveforms, and their phases are shifted by 120 ° in terms of electrical angle.

The U, V, W phase comparators 116bU, 116bV, 116bW perform U (PWM) control in the first inverter 101 by PWM (PWM: pulse width modulation) control based on the magnitude comparison of the U, V, W phase command voltage and the carrier signal SigC. , V, W phase upper and lower arm switches Sp, Sn operation signals are generated. Specifically, the operation signal generation unit 116 performs each of the U, V, and W phases by PWM control based on the magnitude comparison between the signal obtained by normalizing the U, V, and W phase command voltages with the power supply voltage and the carrier signal. An operation signal for the switches Sp and Sn is generated. The driver 117 turns on / off each of the U-, V-, and W-phase switches Sp and Sn in the first inverter 101 based on the operation signal generated by the operation signal generation unit 116.

The control device 110 performs a process of changing the carrier frequency fc of the carrier signal SigC, that is, the switching frequency of each of the switches Sp and Sn. The carrier frequency fc is set high in the low torque region or high rotation region of the rotary electric machine 10 and set low in the high torque region of the rotary electric machine 10. This setting is performed in order to suppress deterioration in controllability of the current flowing through each phase winding.

That is, as the stator 50 becomes coreless, the inductance of the stator 50 can be reduced. Here, when the inductance decreases, the electric time constant of the rotating electric machine 10 decreases. As a result, the ripple of the current flowing through each phase winding increases, the controllability of the current flowing through the winding decreases, and the current control may diverge. The influence of this decrease in controllability can be more remarkable when the current flowing through the winding (for example, the effective value of the current) is included in the low current region than when it is included in the high current region. In order to deal with this problem, in the present modification, the control device 110 changes the carrier frequency fc.

The process of changing the carrier frequency fc will be described with reference to FIG. This process is repeatedly executed by the control device 110 as a process of the operation signal generation unit 116, for example, in a predetermined control cycle.

In step S10, it is determined whether or not the current flowing through the winding 51a of each phase is included in the low current region. This process is a process for determining that the current torque of the rotary electric machine 10 is in the low torque region. The following first and second methods can be given as examples of the method of determining whether or not they are included in the low current region.

<First method>
Based on the d-axis current and the q-axis current converted by the dq converter 112, the estimated torque value of the rotary electric machine 10 is calculated. When it is determined that the calculated estimated torque value is less than the torque threshold value, it is determined that the current flowing through the winding 51a is included in the low current region, and it is determined that the estimated torque value is equal to or greater than the torque threshold value. , It is determined that the high current region is included. Here, the torque threshold may be set to, for example, 1/2 of the starting torque (also referred to as the restraint torque) of the rotating electric machine 10.

<Second method>
When it is determined that the rotation angle of the rotor 40 detected by the angle detector is equal to or higher than the speed threshold value, it is determined that the current flowing through the winding 51a is included in the low current region, that is, the high rotation region. Here, the speed threshold may be set to the rotation speed when the maximum torque of the rotary electric machine 10 becomes the torque threshold, for example.

If a negative determination is made in step S10, it is determined that the current region is high, and the process proceeds to step S11. In step S11, the carrier frequency fc is set to the first frequency fL.

When the affirmative determination is made in step S10, the process proceeds to step S12, and the carrier frequency fc is set to the second frequency fH higher than the first frequency fL.

According to the present modification described above, the carrier frequency fc is set higher when the current flowing through each phase winding is included in the low current region than in the high current region. Therefore, in the low current region, the switching frequencies of the switches Sp and Sn can be increased, and the increase of current ripple can be suppressed. As a result, it is possible to suppress a decrease in current controllability.

On the other hand, when the current flowing through each phase winding is included in the high current region, the carrier frequency fc is set lower than when it is included in the low current region. In the high current region, the amplitude of the current flowing through the winding is larger than that in the low current region, so that the increase in the current ripple due to the lower inductance has less effect on the current controllability. Therefore, in the high current region, the carrier frequency fc can be set lower than in the low current region, and the switching loss of each inverter 101, 102 can be reduced.

In this modification, the following forms can be implemented.

When the carrier frequency fc is set to the first frequency fL and the affirmative determination is made in step S10 of FIG. 32, the carrier frequency fc is gradually changed from the first frequency fL to the second frequency fH. Good.

In addition, when the carrier frequency fc is set to the second frequency fH and the negative determination is made in step S10, the carrier frequency fc may be gradually changed from the second frequency fH to the first frequency fL. ..

-Instead of PWM control, the switch operation signal may be generated by space vector modulation (SVM) control. Even in this case, the change of the switching frequency described above can be applied.

(Modification 9)
In each of the above-described embodiments, the conductor wires for each pair of the phases forming the conductor wire group 81 are connected in parallel as shown in FIG. FIG. 33A is a diagram showing the electrical connection of the first and second conductors 88a and 88b, which are two pairs of conductors. Here, instead of the configuration shown in FIG. 33 (a), as shown in FIG. 33 (b), the first and second conducting wires 88a, 88b may be connected in series.

Also, three or more pairs of multi-layer conductors may be laminated in the radial direction. FIG. 34 shows a configuration in which four pairs of first to fourth conductors 88a to 88d, which are conductors, are stacked. The first to fourth conductive wires 88a to 88d are arranged in the radial direction in the order of the first, second, third and fourth conductive wires 88a, 88b, 88c, 88d from the side closer to the stator core 52. ..

Here, as shown in FIG. 33 (c), the third and fourth conductors 88c and 88d are connected in parallel, the first conductor 88a is connected to one end of the parallel connection body, and the second conductor is connected to the other end. 88b may be connected. The parallel connection can reduce the current density of the conductors connected in parallel, and can suppress heat generation during energization. Therefore, in the configuration in which the tubular stator winding is assembled to the housing (unit base 61) in which the cooling water passage 74 is formed, the first and second conducting wires 88a and 88b that are not connected in parallel contact the unit base 61. The third and fourth conducting wires 88c and 88d arranged on the stator core 52 side and connected in parallel are arranged on the side opposite to the stator core side. This makes it possible to equalize the cooling performance of the conductors 88a to 88d in the multilayer conductor structure.

The radial thickness dimension of the conductor wire group 81 including the first to fourth conductor wires 88a to 88d may be smaller than the circumferential width dimension of one phase in one magnetic pole.

(Modification 10)
The rotary electric machine 10 may have an inner rotor structure (inner rotation structure). In this case, for example, in the housing 30, the stator 50 may be provided radially outside and the rotor 40 may be provided radially inside thereof. In addition, the inverter unit 60 may be provided on one side or both sides of the axial ends of the stator 50 and the rotor 40. 35 is a cross-sectional view of the rotor 40 and the stator 50, and FIG. 36 is an enlarged view of a part of the rotor 40 and the stator 50 shown in FIG.

The configurations shown in FIGS. 35 and 36, which assume the inner rotor structure, are that the rotor 40 and the stator 50 are opposite to each other in the radial direction inside and outside of the configurations shown in FIGS. 8 and 9 that assume the outer rotor structure. It has the same configuration except. Briefly described, the stator 50 has a stator winding 51 having a flat conductor structure and a stator core 52 having no teeth. The stator winding 51 is assembled inside the stator core 52 in the radial direction. The stator core 52 has one of the following configurations, as in the case of the outer rotor structure.
(A) In the stator 50, an inter-conductor member is provided between the conductor portions in the circumferential direction, and as the inter-conductor member, the circumferential width dimension of the inter-conductor member in one magnetic pole is Wt, and the inter-conductor member is saturated. When the magnetic flux density is Bs, the circumferential width of the magnet unit in one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit is Br, a magnetic material having a relationship of Wt × Bs ≦ Wm × Br is used.
(B) In the stator 50, an inter-conductor member is provided between the conductor portions in the circumferential direction, and a non-magnetic material is used as the inter-conductor member.
(C) In the stator 50, the inter-conductor member is not provided between the conductor portions in the circumferential direction.

The same applies to the magnets 91 and 92 of the magnet unit 42. That is, in the magnet unit 42, the magnets 91, 92 are oriented so that the direction of the easy axis of magnetization is parallel to the d-axis on the side of the d-axis, which is the center of the magnetic pole, than on the side of the q-axis, which is the magnetic pole boundary. It is configured using. The details of the magnetization directions and the like of the magnets 91 and 92 are as described above. It is also possible to use an annular magnet 95 (see FIG. 30) in the magnet unit 42.

FIG. 37 is a vertical cross-sectional view of the rotary electric machine 10 in the case of the inner rotor type, which corresponds to FIG. 2 described above. Differences from the configuration of FIG. 2 will be briefly described. In FIG. 37, an annular stator 50 is fixed inside the housing 30, and a rotor 40 is rotatably provided inside the stator 50 with a predetermined air gap in between. Similar to FIG. 2, the bearings 21 and 22 are arranged so as to be biased to either side in the axial direction with respect to the axial center of the rotor 40, whereby the rotor 40 is supported in a cantilever manner. There is. Further, the inverter unit 60 is provided inside the magnet holder 41 of the rotor 40.

FIG. 38 shows another configuration of the rotary electric machine 10 having an inner rotor structure. In FIG. 38, in the housing 30, the rotary shaft 11 is rotatably supported by bearings 21 and 22, and the rotor 40 is fixed to the rotary shaft 11. Similar to the configuration shown in FIG. 2 and the like, the bearings 21 and 22 are arranged so as to be deviated to one side in the axial direction with respect to the axial center of the rotor 40. The rotor 40 has a magnet holder 41 and a magnet unit 42.

The rotating electric machine 10 in FIG. 38 is different from the rotating electric machine 10 in FIG. 37 in that the inverter unit 60 is not provided inside the rotor 40 in the radial direction. The magnet holder 41 is connected to the rotating shaft 11 at a position on the inner side in the radial direction of the magnet unit 42. Further, the stator 50 has a stator winding 51 and a stator core 52, and is attached to the housing 30.

(Modification 11)
Another configuration of the rotating electric machine having the inner rotor structure will be described below. 39 is an exploded perspective view of the rotary electric machine 200, and FIG. 40 is a side sectional view of the rotary electric machine 200. Note that, here, the vertical direction is shown based on the states of FIGS. 39 and 40.

As shown in FIGS. 39 and 40, a rotating electric machine 200 includes a stator 203 having an annular stator core 201 and a multi-phase stator winding 202, and is rotatably arranged inside the stator core 201. And a rotor 204. The stator 203 corresponds to an armature, and the rotor 204 corresponds to a field element. The stator core 201 is configured by laminating a large number of silicon steel plates, and the stator winding 202 is attached to the stator core 201. Although not shown, the rotor 204 has a rotor core and a plurality of permanent magnets as magnet units. The rotor core is provided with a plurality of magnet insertion holes at equal intervals in the circumferential direction. In each of the magnet insertion holes, a permanent magnet magnetized so that the magnetization direction is alternately changed for each adjacent magnetic pole is mounted. The permanent magnets of the magnet unit may have the Halbach array as described in FIG. 23 or a configuration similar thereto. Alternatively, the permanent magnet of the magnet unit is a pole whose orientation direction (magnetization direction) extends in an arc shape between the d axis that is the magnetic pole center and the q axis that is the magnetic pole boundary as described with reference to FIGS. 9 and 30. It is preferable to have an anisotropic characteristic.

Here, the stator 203 may have any one of the following configurations.
(A) In the stator 203, an inter-conductor member is provided between the conductor portions in the circumferential direction, and as the inter-conductor member, the circumferential width dimension of the inter-conductor member in one magnetic pole is Wt, and the inter-conductor member is saturated. When the magnetic flux density is Bs, the circumferential width of the magnet unit in one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit is Br, a magnetic material having a relationship of Wt × Bs ≦ Wm × Br is used.
(B) In the stator 203, an inter-conductor member is provided between the conductor portions in the circumferential direction, and a non-magnetic material is used as the inter-conductor member.
(C) In the stator 203, the inter-conductor members are not provided between the conductor portions in the circumferential direction.

Further, in the rotor 204, the magnet unit is oriented so that the easy axis of magnetization is parallel to the d-axis on the side of the d-axis, which is the center of the magnetic pole, compared to the side of the q-axis, which is the magnetic pole boundary. It is composed of a plurality of magnets.

An annular inverter case 211 is provided on one end side of the rotary electric machine 200 in the axial direction. The inverter case 211 is arranged so that the lower surface of the case is in contact with the upper surface of the stator core 201. In the inverter case 211, a plurality of power modules 212 that form an inverter circuit, a smoothing capacitor 213 that suppresses pulsation (ripple) of voltage / current generated by a switching operation of a semiconductor switching element, and a control board 214 having a controller. A current sensor 215 for detecting a phase current and a resolver stator 216 which is a rotation speed sensor of the rotor 204 are provided. The power module 212 has an IGBT or a diode which is a semiconductor switching element.

Around the periphery of the inverter case 211, a power connector 217 connected to a DC circuit of a battery mounted on the vehicle, and a signal connector 218 used for passing various signals between the rotating electrical machine 200 side and the vehicle side control device. Is provided. The inverter case 211 is covered with a top cover 219. DC power from the vehicle-mounted battery is input through the power connector 217, converted into AC by switching of the power module 212, and sent to the stator winding 202 of each phase.

A bearing unit 221 that rotatably holds the rotation shaft of the rotor 204 and an annular rear case 222 that houses the bearing unit 221 are provided on opposite sides of the inverter case 211 on both axial sides of the stator core 201. It is provided. The bearing unit 221 has, for example, a set of two bearings, and is arranged so as to be biased to one side in the axial direction with respect to the axial center of the rotor 204. However, a plurality of bearings in the bearing unit 221 may be dispersedly provided on both sides of the stator core 201 in the axial direction, and the rotating shaft may be supported on both sides by these bearings. The rotary case 200 is attached to the vehicle side by fastening the rear case 222 to a mounting portion such as a gear case or a transmission of the vehicle by bolting.

A cooling flow path 211a for flowing a refrigerant is formed inside the inverter case 211. The cooling channel 211a is formed by closing a space, which is annularly recessed from the lower surface of the inverter case 211, with the upper surface of the stator core 201. The cooling flow path 211a is formed so as to surround the coil end of the stator winding 202. The module case 212a of the power module 212 is inserted into the cooling flow path 211a. A cooling passage 222a is also formed in the rear case 222 so as to surround the coil end of the stator winding 202. The cooling channel 222a is formed by closing a space, which is annularly recessed from the upper surface of the rear case 222, with the lower surface of the stator core 201.

(Modification 12)
Up to now, the configuration embodied in the rotating field type rotating electric machine has been described, but it is also possible to change the configuration and embody it in the rotating armature type rotating electric machine. FIG. 41 shows the configuration of a rotary armature-type rotary electric machine 230.

In the rotary electric machine 230 of FIG. 41, bearings 232 are fixed to the housings 231a and 231b, respectively, and the rotary shaft 233 is rotatably supported by the bearings 232. The bearing 232 is, for example, an oil-impregnated bearing made of porous metal containing oil. A rotor 234 as an armature is fixed to the rotary shaft 233. The rotor 234 has a rotor core 235 and a multi-phase rotor winding 236 fixed to the outer peripheral portion of the rotor core 235. In the rotor 234, the rotor core 235 has a slotless structure and the rotor winding 236 has a flat conductor wire structure. That is, the rotor winding 236 has a flat structure in which the region for each phase is longer in the circumferential direction than in the radial direction.

Moreover, a stator 237 as a field element is provided on the outer side in the radial direction of the rotor 234. The stator 237 has a stator core 238 fixed to the housing 231a and a magnet unit 239 fixed to the inner peripheral side of the stator core 238. The magnet unit 239 is configured to include a plurality of magnetic poles whose polarities alternate in the circumferential direction. Like the magnet unit 42 and the like described above, the magnetic unit 239 has a magnetic pole boundary q on the side of the d axis that is the magnetic pole center. The orientation is made such that the direction of the easy axis of magnetization is parallel to the d-axis as compared with the side of the axis. The magnet unit 239 has an oriented sintered neodymium magnet, and its intrinsic coercive force is 400 [kA / m] or more and the residual magnetic flux density is 1.0 [T] or more.

The rotating electrical machine 230 of this example is a 2-pole 3-coil brushless coreless motor, the rotor winding 236 is divided into three, and the magnet unit 239 has 2 poles. The number of poles and the number of coils of the brushed motor are various such as 2: 3, 4:10, and 4:21 depending on the application.

A commutator 241 is fixed to the rotating shaft 233, and a plurality of brushes 242 are arranged on the outer side in the radial direction. The commutator 241 is electrically connected to the rotor winding 236 via a conductor wire 243 embedded in the rotating shaft 233. A direct current flows in and out of the rotor winding 236 through the commutator 241, the brush 242, and the conductor wire 243. The commutator 241 is appropriately divided in the circumferential direction according to the number of phases of the rotor winding 236. The brush 242 may be directly connected to a DC power source such as a storage battery via an electric wiring, or may be connected to a DC power source via a terminal block or the like.

The rotation shaft 233 is provided with a resin washer 244 as a seal material between the bearing 232 and the commutator 241. The resin washer 244 suppresses the oil exuding from the bearing 232, which is an oil-impregnated bearing, from flowing out to the commutator 241 side.

(Modification 13)
In the stator winding 51 of the rotating electric machine 10, each conductive wire 82 may have a plurality of insulating coatings inside and outside. For example, a plurality of conducting wires (strands) with an insulating coating may be bundled into one and covered with an outer coating to form the conducting wire 82. In this case, the insulating coating of the wire constitutes the inner insulating coating and the outer coating constitutes the outer insulating coating. Further, it is particularly preferable that the insulating ability of the outer insulating coating of the plurality of insulating coatings of the conductor wire 82 is higher than that of the inner insulating coating. Specifically, the thickness of the outer insulating coating is made thicker than the thickness of the inner insulating coating. For example, the thickness of the outer insulating coating is 100 μm, and the thickness of the inner insulating coating is 40 μm. Alternatively, a material having a lower dielectric constant than the inner insulating film may be used as the outer insulating film. At least one of these may be applied. The strands of wire may be configured as an aggregate of a plurality of conductive materials.

By strengthening the insulation of the outermost layer of the conductor 82 as described above, it becomes suitable for use in a high-voltage vehicle system. Further, the rotating electric machine 10 can be appropriately driven even in a high altitude where the atmospheric pressure is low.

(Modification 14)
In the conductive wire 82 having a plurality of insulating coatings inside and outside, at least one of the coefficient of linear expansion (coefficient of linear expansion) and the adhesive strength may be different between the outer insulating coating and the inner insulating coating. The structure of the conductor wire 82 in this modification is shown in FIG.

In FIG. 42, the conducting wire 82 includes a plurality of (four in the drawing) element wires 181, an outer layer coating 182 (outer insulating coating) made of, for example, resin surrounding the plurality of element wires 181, and each element in the outer layer coating 182. And an intermediate layer 183 (intermediate insulating coating) filled around the line 181. The strand 181 has a conductive portion 181a made of a copper material and a conductor coating 181b (inner insulating coating) made of an insulating material. When viewed as a stator winding, the outer coating 182 insulates the phases. The strand 181 may be configured as an aggregate of a plurality of conductive materials.

The intermediate layer 183 has a higher linear expansion coefficient than the conductor coating 181b of the strand 181 and a lower linear expansion coefficient than the outer coating 182. That is, the linear expansion coefficient of the conductive wire 82 is higher toward the outside. Generally, the outer layer coating 182 has a higher coefficient of linear expansion than the conductor coating 181b, but by providing the intermediate layer 183 having a linear expansion coefficient between them, the intermediate layer 183 functions as a cushioning material. Simultaneous cracking on the outer layer side and the inner layer side can be prevented.

Further, in the conductor 82, the conductive portion 181a and the conductor coating 181b are adhered to each other on the wire 181, and the conductor coating 181b and the intermediate layer 183 are adhered to each other, and the intermediate layer 183 and the outer coating 182 are adhered to each other. Then, the adhesive strength becomes weaker toward the outer side of the conducting wire 82. That is, the adhesive strength between the conductive portion 181a and the conductor coating 181b is weaker than the adhesive strength between the conductor coating 181b and the intermediate layer 183 and the adhesive strength between the intermediate layer 183 and the outer coating 182. Further, comparing the adhesive strengths of the conductor coating 181b and the intermediate layer 183 with the adhesive strengths of the intermediate layer 183 and the outer coating 182, it is preferable that the latter (outer) is weaker or equivalent. It should be noted that the magnitude of the adhesive strength between the respective coatings can be grasped, for example, by the tensile strength or the like required when peeling the two coating layers. By setting the adhesive strength of the conductive wire 82 as described above, it is possible to suppress cracking (co-cracking) both on the inner layer side and the outer layer side even if a difference in temperature between the inside and outside occurs due to heat generation or cooling. ..

Here, the heat generation and the temperature change of the rotating electric machine mainly occur as a copper loss generated from the conductive portion 181a of the wire 181 and an iron loss generated from within the iron core. Is transmitted from outside the conductive portion 181a or the conductive wire 82, and the intermediate layer 183 does not have a heat source. In this case, since the intermediate layer 183 has an adhesive force capable of serving as a cushion for both, the simultaneous cracking can be prevented. Therefore, it can be preferably used even in the field of high withstand voltage or large temperature change such as vehicle application.

Supplement to the following. The strand 181 may be, for example, an enameled wire, and in such a case, has a resin coating layer (conductor coating 181b) of PA, PI, PAI or the like. Further, it is desirable that the outer layer coating 182 on the outer side of the wire 181 is made of the same PA, PI, PAI or the like and has a large thickness. Thereby, the destruction of the coating film due to the difference in linear expansion coefficient is suppressed. The outer layer coating 182 has a dielectric constant of PPS, PEEK, fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, LCP, etc., in addition to thickening the above materials such as PA, PI, and PAI. It is also desirable to use a material smaller than PI or PAI in order to increase the conductor density of the rotating machine. If these resins are used, even if they are thinner than the PI and PAI coatings equivalent to the conductor coating 181b or have the same thickness as the conductor coating 181b, the insulating ability thereof can be increased, whereby the occupancy rate of the conductive portion is increased. Can be increased. Generally, the resin has better insulation than the insulating coating of enamel wire. Of course, there are cases where the dielectric constant is deteriorated depending on the molding state and the mixture. Among them, PPS and PEEK have a coefficient of linear expansion that is generally larger than that of the enamel coating, but are smaller than those of other resins, and are therefore suitable as the outer layer coating of the second layer.

Further, the adhesive strength between the two kinds of coatings (intermediate insulating coating and outer insulating coating) on the outside of the wire 181 and the enamel coating of the wire 181 is the adhesive strength between the copper wire and the enamel coating on the wire 181. It is desirable to be weaker than Sa. This suppresses the phenomenon that the enamel coating and the two types of coatings are destroyed at once.

When a water-cooled structure, a liquid-cooled structure, or an air-cooled structure is added to the stator, it is considered that thermal stress or impact stress is basically applied to the outer layer coating 182 first. However, even in the case where the insulating layer of the wire 181 and the two types of coatings are made of different resins, the thermal stress and the impact stress can be reduced by providing a portion where the coatings are not adhered. That is, the insulating structure is formed by providing a gap between the element wire (enamel wire) and arranging fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, and LCP. In this case, it is desirable to bond the outer layer coating and the inner layer coating using an adhesive material such as epoxy having a low dielectric constant and a low linear expansion coefficient. By doing so, not only the mechanical strength but also the destruction of the coating due to the friction due to the vibration of the conductive portion or the destruction of the outer coating due to the difference in the linear expansion coefficient can be suppressed.

The outermost layer fixing, which is generally the final step around the stator winding, is responsible for the mechanical strength, fixing, etc. of the conductor wire 82 having the above-mentioned structure, and the moldability of epoxy, PPS, PEEK, LCP or the like. It is preferable to use a resin which has good properties and has properties such as dielectric constant and linear expansion coefficient similar to those of the enamel coating.

Generally, resin potting with urethane or silicone is generally used, but the linear expansion coefficient of the resin is nearly double that of other resins, and thermal stress that can shear the resin is generated. Therefore, it is unsuitable for applications of 60 V or higher, which are used internationally under strict insulation regulations. In this respect, according to the final insulation process which is easily made by injection molding or the like with epoxy, PPS, PEEK, LCP, etc., it is possible to achieve the above-mentioned requirements.

Modifications other than the above are listed below.

The radial distance DM between the armature-side surface of the magnet unit 42 and the rotor shaft center may be 50 mm or more. Specifically, for example, in the radial direction between the radially inner surface of the magnet unit 42 (specifically, the first and second magnets 91 and 92) shown in FIG. 4 and the axial center of the rotor 40. The distance DM may be 50 mm or more.

As a slotless rotating electric machine, a small-scale one is known, whose output is used for models of tens to hundreds of W class. The present inventor does not understand a case in which a slotless structure is adopted in a large industrial rotary electric machine that generally exceeds 10 kW. The present inventor examined the reason.

The mainstream rotating electric machines in recent years are roughly classified into the following four types. The rotary electric machines are a brush motor, a basket-type induction motor, a permanent magnet synchronous motor, and a reluctance motor.

Excitation current is supplied to the brushed motor via the brush. Therefore, in the case of a brushed motor of a large machine, the brush becomes large and maintenance becomes complicated. As a result, along with the remarkable development of semiconductor technology, it has been replaced by a brushless motor such as an induction motor. On the other hand, in the world of small motors, coreless motors have been supplied to the majority due to their advantages of low inertia and economy.

In the basket-type induction motor, the magnetic field generated by the stator winding on the primary side is received by the iron core of the secondary-side rotor, and an induction current is concentrated in the basket-type conductor to form a reaction magnetic field. This is the principle of generating torque. Therefore, from the viewpoint of small size and high efficiency of the device, it is not always a good idea to eliminate the iron cores on both the stator side and the rotor side.

Reluctance motors are motors that utilize reluctance changes in the iron core, and it is not desirable to eliminate the iron core in principle.

In permanent magnet synchronous motors, the IPM (that is, embedded magnet type rotor) has become the mainstream in recent years, and especially in large machines, it is often the IPM unless there are special circumstances.

The IPM has the characteristic of having both magnet torque and reluctance torque, and is operated while the ratio of those torques is adjusted in a timely manner by the inverter control. Therefore, the IPM is a motor that is small and has excellent controllability.

According to the analysis of the present disclosure, the torque of the rotor surface that generates the magnet torque and the reluctance torque is determined by the distance DM in the radial direction between the surface of the magnet unit on the armature side in the radial direction and the axial center of the rotor, that is, FIG. 43 is a diagram in which the radius of the stator core of a general inner rotor is plotted on the horizontal axis.

The magnet torque has its potential determined by the magnetic field strength generated by the permanent magnet as shown in the following equation (eq1), whereas the reluctance torque has an inductance, especially q as shown in the following equation (eq2). The magnitude of the axial inductance determines its potential.

Magnet torque = k · Ψ · Iq ···· (eq1)
Reluctance torque = k · (Lq-Ld) · Iq · Id (eq2)
Here, the magnetic field strength of the permanent magnet and the magnitude of the inductance of the winding are compared by DM. The magnetic field strength generated by the permanent magnet, that is, the amount of magnetic flux Ψ, is proportional to the total area of the permanent magnet on the surface facing the stator. If it is a cylindrical rotor, it has the surface area of a cylinder. Strictly speaking, since there are N poles and S poles, they are proportional to the area occupied by half the cylindrical surface. The surface area of a cylinder is proportional to the radius of the cylinder and the length of the cylinder. That is, if the cylinder length is constant, it is proportional to the radius of the cylinder.

On the other hand, the inductance Lq of the winding has a low sensitivity though it depends on the shape of the iron core, and is rather proportional to the square of the number of windings of the stator winding, so that the dependence on the number of windings is high. When μ is the magnetic permeability of the magnetic circuit, N is the number of turns, S is the cross-sectional area of the magnetic circuit, and δ is the effective length of the magnetic circuit, the inductance is L = μ · N̂2 × S / δ. Since the number of turns of the winding depends on the size of the winding space, in the case of a cylindrical motor, it depends on the winding space of the stator, that is, the slot area. As shown in FIG. 44, the slot area is proportional to the product a × b of the length dimension a in the circumferential direction and the length dimension b in the radial direction, because the shape of the slot is substantially quadrangular.

The length of the slot in the circumferential direction increases as the diameter of the cylinder increases, so it is proportional to the diameter of the cylinder. The radial dimension of the slot is in proportion to the diameter of the cylinder. That is, the slot area is proportional to the square of the diameter of the cylinder. Further, as can be seen from the above equation (eq2), the reluctance torque is proportional to the square of the stator current, so the performance of the rotating electrical machine is determined by how large the current can flow, and its performance depends on the slot area of the stator. Dependent. From the above, if the length of the cylinder is constant, the reluctance torque is proportional to the square of the diameter of the cylinder. Based on this, FIG. 43 is a diagram in which the relationship between the magnet torque and the reluctance torque and DM is plotted.

As shown in FIG. 43, the magnet torque linearly increases with respect to DM, and the reluctance torque increases quadratically with respect to DM. It can be seen that the magnet torque is dominant when DM is relatively small, and the reluctance torque is dominant as the stator core radius increases. The present inventor has come to the conclusion that the intersection of the magnet torque and the reluctance torque in FIG. 43 is approximately in the vicinity of the stator core radius = 50 mm under predetermined conditions. In other words, it is difficult to eliminate the iron core in a large machine field because it is the current mainstream to utilize reluctance torque in a 10 kW class motor whose stator iron core radius exceeds 50 mm. It is estimated that this is one of the reasons why the slotless structure is not adopted.

In the case of a rotating electric machine that uses an iron core for the stator, magnetic saturation of the iron core is always a problem. Particularly in radial gap type rotating electrical machines, the vertical cross-sectional shape of the rotating shaft is fan-shaped per magnetic pole, and the width of the magnetic path becomes narrower toward the inner peripheral side of the equipment, and the inner diameter of the teeth forming the slots is the performance of the rotating electrical machine. Set limits. No matter how high-performance the permanent magnet is used, if magnetic saturation occurs in this part, the performance of the permanent magnet cannot be sufficiently brought out. In order to prevent magnetic saturation at this portion, the inner diameter must be designed to be large, resulting in an increase in the size of the device.

For example, in a three-phase winding in a distributed-winding rotary electric machine, magnetic flux is shared by three to six teeth per magnetic pole, but the magnetic flux tends to concentrate on the teeth in the front in the circumferential direction. The magnetic flux does not flow evenly through the three to six teeth. In this case, the magnetic flux intensively flows in a part (for example, one or two) of the teeth, and the teeth that are magnetically saturated also move in the circumferential direction as the rotor rotates. This is also a factor that causes slot ripple.

From the above, we would like to abolish teeth in the slotless rotating electrical machine with DM of 50 mm or more in order to eliminate magnetic saturation. However, when the teeth are eliminated, the magnetic resistance of the magnetic circuits in the rotor and the stator increases, and the torque of the rotating electric machine decreases. The reason for the increase in magnetic resistance is, for example, that the air gap between the rotor and the stator becomes large. Therefore, there is room for improvement in increasing the torque in the above-described slotless rotary electric machine having a DM of 50 mm or more. Therefore, there is a great merit in applying the above-described configuration capable of increasing the torque to the rotary electric machine having the slotless structure in which the DM is 50 mm or more.

Not only in the rotating electric machine having the outer rotor structure but also in the rotating electric machine having the inner rotor structure, the radial distance DM between the armature-side surface of the magnet unit and the rotor shaft center is set to 50 mm or more. May be.

In the stator winding 51 of the rotary electric machine 10, the linear portion 83 of the conductor wire 82 may be provided in a single layer in the radial direction. Further, when the linear portion 83 is arranged in a plurality of layers inside and outside in the radial direction, the number of layers may be arbitrary and may be three layers, four layers, five layers, six layers or the like.

-For example, in the configuration of FIG. 2, the rotary shaft 11 is provided so as to project to both the one end side and the other end side of the rotary electric machine 10 in the axial direction, but this is modified so that it projects only to one end side. Good. In this case, the rotary shaft 11 may be provided so as to extend outward in the axial direction with the end portion being a portion that is cantilevered and supported by the bearing unit 20. In this configuration, since the rotating shaft 11 does not project inside the inverter unit 60, the internal space of the inverter unit 60, more specifically, the internal space of the tubular portion 71 can be used more widely.

-In the rotating electric machine 10 having the above-described configuration, the bearings 21 and 22 are configured to use non-conductive grease, but this may be changed and the bearings 21 and 22 may be configured to use conductive grease. For example, a conductive grease containing metal particles, carbon particles, or the like is used.

-As a configuration for rotatably supporting the rotary shaft 11, bearings may be provided at two positions on the one end side and the other end side in the axial direction of the rotor 40. In this case, in terms of the configuration of FIG. 1, it is preferable that bearings are provided at two positions on one end side and the other end side with the inverter unit 60 interposed therebetween.

In the rotating electric machine 10 having the above-described configuration, in the rotor 40, the intermediate portion 45 of the magnet holder 41 has the inner shoulder portion 49a and the emotional outer shoulder portion 49b. However, these shoulder portions 49a and 49b are eliminated and flattened. It is also possible to adopt a configuration having a different surface.

In the rotating electric machine 10 having the above-described configuration, the conductor 82a in the conductor wire 82 of the stator winding 51 is configured as an assembly of a plurality of element wires 86, but this is changed and a rectangular conductor wire having a rectangular cross section is used as the conductor wire 82. It may be configured. Alternatively, a round conductor having a circular cross section or an elliptical cross section may be used as the conductor 82.

In the rotating electric machine 10 having the above-described configuration, the inverter unit 60 is provided inside the stator 50 in the radial direction, but instead, the inverter unit 60 may not be provided inside the stator 50 in the radial direction. .. In this case, it is possible to set a space in the inner region of the stator 50 on the radially inner side. Further, it is possible to dispose a component different from the inverter unit 60 in the internal area.

The rotary electric machine 10 having the above configuration may not have the housing 30. In this case, for example, the rotor 40, the stator 50, and the like may be held in a part of the wheel or other vehicle parts.

(Embodiment as in-wheel motor for vehicle)
Next, an embodiment in which the rotary electric machine is provided as an in-wheel motor integrally with the wheels of the vehicle will be described. 45 is a perspective view showing a wheel 400 of the in-wheel motor structure and its peripheral structure, FIG. 46 is a vertical cross-sectional view of the wheel 400 and its peripheral structure, and FIG. 47 is an exploded perspective view of the wheel 400. is there. Each of these drawings is a perspective view of the wheel 400 as viewed from the inside of the vehicle. Note that the in-wheel motor structure of the present embodiment can be applied to various forms in a vehicle. For example, in a vehicle having two wheels on the front and the rear of the vehicle, two wheels on the front side of the vehicle and two wheels on the rear side of the vehicle can be used. It is possible to apply the in-wheel motor structure of this embodiment to two wheels or four wheels before and after the vehicle. However, application to a vehicle in which at least one of the front and rear of the vehicle has one wheel is also possible. The in-wheel motor is an example of application as a vehicle drive unit.

As shown in FIGS. 45 to 47, a wheel 400 is, for example, a tire 401 which is a well-known pneumatic tire, a wheel 402 fixed to the inner peripheral side of the tire 401, and an inner peripheral side of the wheel 402. And a rotating electric machine 500. Rotating electric machine 500 has a fixed part that is a part that includes a stator (stator) and a rotary part that is a part that includes a rotor (rotor). The fixed part is fixed to the vehicle body side, and the rotary part is The tire 401 and the wheel 402 are fixed to the wheel 402, and the tire 401 and the wheel 402 are rotated by the rotation of the rotating portion. The detailed configuration of the rotating electric machine 500 including the fixed portion and the rotating portion will be described later.

Further, a suspension device that holds the wheel 400 with respect to a vehicle body (not shown), a steering device that makes the direction of the wheel 400 variable, and a brake device that brakes the wheel 400 are attached to the wheel 400 as peripheral devices. Has been.

The suspension device is an independent suspension type suspension, and any type such as trailing arm type, strut type, wishbone type, multi-link type can be applied. In this embodiment, as the suspension device, the lower arm 411 is provided so as to extend toward the center of the vehicle body, and the suspension arm 412 and the spring 413 are provided so as to extend in the vertical direction. The suspension arm 412 may be configured as a shock absorber, for example. However, its detailed illustration is omitted. Each of the lower arm 411 and the suspension arm 412 is connected to the vehicle body side and is also connected to a disk-shaped base plate 405 fixed to a fixed portion of the rotating electric machine 500. As shown in FIG. 46, on the rotary electric machine 500 side (base plate 405 side), a lower arm 411 and a suspension arm 412 are coaxially supported by support shafts 414 and 415.

Also, as the steering device, for example, a rack & pinion type structure, a ball & nut type structure, a hydraulic power steering system, an electric power steering system can be applied. In this embodiment, a rack device 421 and a tie rod 422 are provided as a steering device, and the rack device 421 is connected to the base plate 405 on the rotary electric machine 500 side via the tie rod 422. In this case, when the rack device 421 is operated with the rotation of a steering shaft (not shown), the tie rod 422 moves in the vehicle left-right direction. As a result, the wheel 400 rotates about the support shafts 414 and 415 of the lower arm 411 and the suspension arm 412, and the wheel direction is changed.

Applying disc brakes and drum brakes is suitable as the braking device. In the present embodiment, a disc rotor 431 fixed to the rotating shaft 501 of the rotating electric machine 500 and a brake caliper 432 fixed to the base plate 405 on the rotating electric machine 500 side are provided as the braking device. In the brake caliper 432, a brake pad is operated by hydraulic pressure or the like, and when the brake pad is pressed against the disc rotor 431, a braking force due to friction is generated and rotation of the wheel 400 is stopped.

Further, the wheel 400 is provided with a housing duct 440 for housing the electrical wiring H1 extending from the rotating electric machine 500 and the cooling pipe H2. The accommodating duct 440 is provided so as to extend along the end surface of the rotating electric machine 500 from the end of the rotating electric machine 500 on the side of the fixed portion and avoid the suspension arm 412, and is fixed to the suspension arm 412 in this state. As a result, the connection position of the accommodation duct 440 in the suspension arm 412 has a fixed positional relationship with the base plate 405. Therefore, it is possible to suppress the stress generated in the electric wiring H1 and the cooling pipe H2 due to the vibration of the vehicle and the like. The electric wiring H1 is connected to an in-vehicle power supply unit or an in-vehicle ECU (not shown), and the cooling pipe H2 is connected to a radiator (not shown).

Next, the configuration of the rotary electric machine 500 used as an in-wheel motor will be described in detail. In this embodiment, an example in which the rotary electric machine 500 is applied to an in-wheel motor is shown. The rotary electric machine 500 has excellent operation efficiency and output as compared with the motor of the vehicle drive unit having a speed reducer as in the conventional technique. That is, if the rotary electric machine 500 is used for a purpose in which a practical price can be realized by reducing the cost as compared with the related art, it may be used as a motor for purposes other than the vehicle drive unit. Even in such a case, as in the case of being applied to the in-wheel motor, excellent performance is exhibited. The operating efficiency refers to an index used during a test in a driving mode that derives the fuel efficiency of the vehicle.

An outline of the rotating electric machine 500 is shown in FIGS. 48 to 51. 48 is a side view of the rotary electric machine 500 as seen from the protruding side (inside the vehicle) of the rotary shaft 501, and FIG. 49 is a vertical sectional view of the rotary electric machine 500 (a sectional view taken along the line 49-49 in FIG. 48). 50 is a horizontal cross-sectional view (cross-sectional view taken along line 50-50 of FIG. 49) of rotating electric machine 500, and FIG. 51 is an exploded cross-sectional view in which constituent elements of rotating electric machine 500 are disassembled. In the following description, the rotation shaft 501 has a direction extending outward in the vehicle body direction as an axial direction in FIG. 51, and a direction radially extending from the rotation shaft 501 as a radial direction. In FIG. 48, the center of the rotation shaft 501, in other words, For example, two directions that extend circumferentially from an arbitrary point other than the rotation center of the rotating portion on the center line drawn to make a cross section 49 passing through the rotation center of the rotating portion are both circumferential directions. In other words, the circumferential direction may be either a clockwise direction starting from an arbitrary point on the cross section 49 or a counterclockwise direction. 49, the right side is the vehicle outside and the left side is the vehicle inside in FIG. 49. In other words, in the vehicle mounted state, the rotor 510, which will be described later, is arranged on the outer side of the vehicle body with respect to the rotor cover 670.

The rotary electric machine 500 according to the present embodiment is an outer rotor type surface magnet type rotary electric machine. The rotary electric machine 500 is roughly provided with a rotor 510, a stator 520, an inverter unit 530, a bearing 560, and a rotor cover 670. All of these members are coaxially arranged with respect to a rotary shaft 501 provided integrally with the rotor 510, and are assembled in a predetermined order in the axial direction to form the rotary electric machine 500.

In the rotating electric machine 500, the rotor 510 and the stator 520 each have a cylindrical shape, and are arranged to face each other with an air gap interposed therebetween. When the rotor 510 rotates integrally with the rotating shaft 501, the rotor 510 rotates on the radially outer side of the stator 520. The rotor 510 corresponds to a “field element”, and the stator 520 corresponds to an “armature”.

The rotor 510 has a substantially cylindrical rotor carrier 511 and an annular magnet unit 512 fixed to the rotor carrier 511. The rotary shaft 501 is fixed to the rotor carrier 511.

The rotor carrier 511 has a cylindrical portion 513. The magnet unit 512 is fixed to the inner peripheral surface of the cylindrical portion 513. That is, the magnet unit 512 is provided so as to be surrounded by the cylindrical portion 513 of the rotor carrier 511 from the outside in the radial direction. Further, the cylindrical portion 513 has a first end and a second end that face each other in the axial direction. The first end is located outside the vehicle body, and the second end is located along the base plate 405. In the rotor carrier 511, an end plate 514 is continuously provided at the first end of the cylindrical portion 513. That is, the cylindrical portion 513 and the end plate 514 have an integrated structure. The second end of the cylindrical portion 513 is open. The rotor carrier 511 is made of, for example, a cold rolled steel plate (SPCC or SPHC having a plate thickness thicker than SPCC) having sufficient mechanical strength, forging steel, carbon fiber reinforced plastic (CFRP), or the like.

The axial length of the rotary shaft 501 is longer than the axial dimension of the rotor carrier 511. In other words, the rotary shaft 501 projects toward the open end side (inward direction of the vehicle) of the rotor carrier 511, and the above-described brake device or the like is attached to the end portion on the projecting side.

A through hole 514a is formed in the center of the end plate 514 of the rotor carrier 511. The rotary shaft 501 is fixed to the rotor carrier 511 while being inserted into the through hole 514 a of the end plate 514. The rotary shaft 501 has a flange 502 extending in a direction intersecting (orthogonal to) the axial direction at a portion where the rotor carrier 511 is fixed, and the flange and a surface of the end plate 514 outside the vehicle are surface-bonded to each other. In this state, the rotary shaft 501 is fixed to the rotor carrier 511. In addition, in the wheel 400, the wheel 402 is fixed by using a fastener such as a bolt that is erected from the flange 502 of the rotating shaft 501 in the vehicle outer direction.

The magnet unit 512 is composed of a plurality of permanent magnets arranged so that the polarities of the magnets 512 alternate along the circumferential direction of the rotor 510. Thereby, the magnet unit 512 has a plurality of magnetic poles in the circumferential direction. The permanent magnet is fixed to the rotor carrier 511 by adhesion, for example. The magnet unit 512 has the configuration described as the magnet unit 42 in FIGS. 8 and 9 of the first embodiment, and is a permanent magnet having an intrinsic coercive force of 400 [kA / m] or more and a residual magnetic flux. A sintered neodymium magnet having a density Br of 1.0 [T] or higher is used.

Like the magnet unit 42 shown in FIG. 9 and the like, the magnet unit 512 has a first magnet 91 and a second magnet 92 that are polar anisotropic magnets and have polarities different from each other. As described with reference to FIGS. 8 and 9, in each of the magnets 91 and 92, the direction of the easy axis of magnetization differs between the d-axis side (portion near the d-axis) and the q-axis side (portion near the q-axis). On the d-axis side, the direction of the easy axis of magnetization is close to the direction parallel to the d-axis, and on the q-axis side, the direction of the easy axis of magnetization is close to the direction orthogonal to the q-axis. An arc-shaped magnet magnetic path is formed by the orientation according to the direction of the easy axis of magnetization. In each of the magnets 91 and 92, the easy axis of magnetization may be oriented parallel to the d axis on the d-axis side, and the direction of easy magnetization may be orthogonal to the q axis on the q-axis side. In short, the magnet unit 512 is configured such that the direction of the easy axis of magnetization is closer to the d-axis on the side of the d-axis, which is the center of the magnetic pole, than the side of the q-axis, which is the magnetic pole boundary. ..

According to each of the magnets 91 and 92, the magnetic flux of the magnet on the d axis is strengthened and the change of the magnetic flux near the q axis is suppressed. As a result, it is possible to preferably realize the magnets 91 and 92 in which the surface magnetic flux changes gently from the q-axis to the d-axis in each magnetic pole. As the magnet unit 512, the configuration of the magnet unit 42 shown in FIGS. 22 and 23 or the configuration of the magnet unit 42 shown in FIG. 30 can be used.

The magnet unit 512 has a rotor core (back yoke) formed by axially stacking a plurality of electromagnetic steel plates on the side of the cylindrical portion 513 of the rotor carrier 511, that is, on the outer peripheral surface side. Good. That is, it is possible to provide the rotor core on the radially inner side of the cylindrical portion 513 of the rotor carrier 511 and to provide the permanent magnets (magnets 91, 92) on the radially inner side of the rotor core.

As shown in FIG. 47, the cylindrical portion 513 of the rotor carrier 511 is formed with recesses 513a extending in the axial direction at predetermined circumferential intervals. The concave portion 513a is formed by, for example, press working, and as shown in FIG. 52, a convex portion 513b is formed on the inner peripheral surface side of the cylindrical portion 513 at a position on the back side of the concave portion 513a. On the other hand, on the outer peripheral surface side of the magnet unit 512, a concave portion 512a is formed so as to match the convex portion 513b of the cylindrical portion 513, and the convex portion 513b of the cylindrical portion 513 enters the concave portion 512a, so that the magnet unit 512 is formed. The positional displacement in the circumferential direction is suppressed. That is, the convex portion 513b on the rotor carrier 511 side functions as a rotation stopping portion of the magnet unit 512. The method of forming the convex portion 513b may be any method other than press working.

In FIG. 52, the directions of the magnet magnetic paths in the magnet unit 512 are indicated by arrows. The magnet magnetic path extends in an arc shape so as to straddle the q-axis which is the magnetic pole boundary, and the d-axis which is the center of the magnetic pole is oriented parallel or nearly parallel to the d-axis. The magnet unit 512 has recesses 512b formed on the inner peripheral surface thereof at positions corresponding to the q-axis. In this case, in the magnet unit 512, the length of the magnet magnetic path is different between the side closer to the stator 520 (lower side in the figure) and the far side (upper side in the figure), and the side closer to the stator 520 is magnetized. The path length is short, and the recess 512b is formed at the position where the magnet magnetic path length is the shortest. That is, in the magnet unit 512, considering that it is difficult to generate a sufficient magnet magnetic flux in a place where the magnet magnetic path length is short, the magnet is deleted in a place where the magnet magnetic flux is weak.

Here, the effective magnetic flux density Bd of the magnet increases as the length of the magnetic circuit passing inside the magnet increases. In addition, the permeance coefficient Pc and the effective magnetic flux density Bd of the magnet have a relationship that when one of them becomes higher, the other becomes higher. According to the configuration of FIG. 52 described above, it is possible to reduce the amount of magnets while suppressing a decrease in the permeance coefficient Pc that is an index of the height of the effective magnetic flux density Bd of the magnets. In the BH coordinate, the intersection of the permeance line and the demagnetization curve corresponding to the shape of the magnet is the operating point, and the magnetic flux density at that operating point is the effective magnetic flux density Bd of the magnet. In the rotary electric machine 500 of the present embodiment, the stator 520 has a reduced amount of iron, and in such a configuration, the method of setting the magnetic circuit across the q axis is extremely effective.

Also, the recess 512b of the magnet unit 512 can be used as an air passage extending in the axial direction. Therefore, it is possible to improve the air cooling performance.

Next, the structure of the stator 520 will be described. The stator 520 has a stator winding 521 and a stator core 522. FIG. 53 is an exploded perspective view of the stator winding 521 and the stator core 522.

The stator winding 521 is composed of a plurality of phase windings wound in a substantially tubular shape (annular shape), and a stator core 522 as a base member is attached to the inside of the stator winding 521 in the radial direction. There is. In this embodiment, the stator winding 521 is configured as a three-phase winding by using the U-phase, V-phase, and W-phase windings. Each phase winding is composed of inner and outer two-layer conductor wires 523 in the radial direction. The stator 520 is characterized by having a slotless structure and a flat conductor wire structure of the stator winding 521, like the above-mentioned stator 50, and is different from the stator 50 shown in FIGS. 8 to 16. It has a similar or similar configuration.

The structure of the stator core 522 will be described. Similar to the stator core 52 described above, the stator core 522 has a cylindrical shape in which a plurality of electromagnetic steel plates are laminated in the axial direction and has a predetermined thickness in the radial direction. The stator winding 521 is assembled on the radially outer side on the side of the rotor 510. The outer peripheral surface of the stator core 522 has a curved surface shape without unevenness, and when the stator winding 521 is assembled, the conductor wire 523 forming the stator winding 521 is attached to the outer peripheral surface of the stator core 522. They are arranged side by side in the circumferential direction. The stator core 522 functions as a back core.

The stator 520 may use any of the following (A) to (C).
(A) In the stator 520, an inter-conductor member is provided between each conductor 523 in the circumferential direction, and as the inter-conductor member, the circumferential width dimension of the inter-conductor member in one magnetic pole is Wt, and the inter-conductor member is saturated. When the magnetic flux density is Bs, the circumferential width of the magnet unit 512 in one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit 512 is Br, a magnetic material having a relationship of Wt × Bs ≦ Wm × Br is used. There is.
(B) In the stator 520, an inter-conductor member is provided between each conductor 523 in the circumferential direction, and a non-magnetic material is used as the inter-conductor member.
(C) In the stator 520, a member between conductors is not provided between the conductors 523 in the circumferential direction.

According to such a configuration of the stator 520, the inductance is smaller than that of a general electric rotating machine having a teeth structure in which teeth (iron cores) for establishing a magnetic path are provided between the conductor portions as the stator windings. Will be reduced. Specifically, the inductance can be reduced to 1/10 or less. In this case, since the impedance decreases as the inductance decreases, it is possible to increase the output power with respect to the input power in the rotary electric machine 500, and thus contribute to the torque increase. Further, it becomes possible to provide a rotating electric machine with a large output as compared with a rotating electric machine using an embedded magnet type rotor that performs torque output using the voltage of the impedance component (in other words, uses reluctance torque). ing.

In the present embodiment, the stator winding 521 is integrally molded with the stator core 522 by a molding material (insulating member) made of resin or the like, and the molding material is provided between the conductor wires 523 arranged in the circumferential direction. It has an intervening structure. With this configuration, the stator 520 of this embodiment corresponds to the configuration (B) of the above (A) to (C). Further, the conductor wires 523 adjacent to each other in the circumferential direction are arranged such that their end faces in the circumferential direction are in contact with each other, or are arranged in proximity to each other with a minute gap therebetween. Good. When the configuration (A) is adopted, the stator core 522 is adjusted in accordance with the direction of the conductor wire 523 in the axial direction, that is, in the case of the stator winding 521 having a skew structure, for example, in accordance with the skew angle. A protrusion may be provided on the outer peripheral surface.

Next, the structure of the stator winding 521 will be described with reference to FIG. FIG. 54 is a front view showing the stator winding 521 developed in a plane shape. FIG. 54 (a) shows each conductor wire 523 positioned in the outer layer in the radial direction, and FIG. 54 (b) shows the diameter. Each conducting wire 523 located in the inner layer in the direction is shown.

The stator winding 521 is formed in an annular shape by distributed winding. In the stator winding 521, a conductive wire material is wound in two radial inner and outer layers, and the inner conductor wire 523 and the outer conductor wire 523 are skewed in different directions (Fig. 54 (a), 54 (b)). The conductors 523 are insulated from each other. The conducting wire 523 is preferably configured as an assembly of a plurality of element wires 86 (see FIG. 13). Further, for example, two conducting wires 523 having the same phase and the same energizing direction are arranged side by side in the circumferential direction. In the stator winding 521, two conductors 523 in the radial direction and two conductors 523 in the circumferential direction (that is, a total of four) constitute one conductor part of the same phase, and each conductor part is one in one magnetic pole. It is provided.

In the conductor portion, it is preferable that the radial thickness dimension thereof is smaller than the circumferential width dimension of one phase in one magnetic pole, so that the stator winding 521 has a flat conductor structure. Specifically, for example, in the stator winding 521, one conductor wire portion of the same phase may be configured by the two conductor wires 523 in the radial direction and the four conductor wires 523 in the circumferential direction (that is, eight in total). Alternatively, in the conductor cross section of the stator winding 521 shown in FIG. 50, the width dimension in the circumferential direction may be larger than the thickness dimension in the radial direction. The stator winding 51 shown in FIG. 12 can be used as the stator winding 521. However, in this case, it is necessary to secure a space for housing the coil end of the stator winding in the rotor carrier 511.

In the stator winding 521, the conductor wires 523 are arranged side by side in the circumferential direction while being inclined at a predetermined angle on the coil side 525 that overlaps the stator core 522 inward and outward in the radial direction, and at the same time, outside the stator core 522 in the axial direction. The coil ends 526 on both sides, which are defined as follows, are inverted (folded back) inward in the axial direction to form a continuous connection. FIG. 54A shows a range serving as the coil side 525 and a range serving as the coil end 526. The inner-layer-side conductor wire 523 and the outer-layer-side conductor wire 523 are connected to each other at the coil end 526, so that the conductor wire 523 is connected to the conductor wire 523 every time the conductor wire 523 is axially reversed (turned back) at the coil end 526. The inner layer side and the outer layer side are alternately switched. In short, in the stator winding 521, the inner and outer layers are switched in accordance with the reversal of the direction of the current in each of the conducting wires 523 continuous in the circumferential direction.

Further, in the stator winding 521, two kinds of skews having different skew angles are applied between the end regions that are both ends in the axial direction and the central region sandwiched between the end regions. That is, as shown in FIG. 55, in the conducting wire 523, the skew angle θs1 in the central region is different from the skew angle θs2 in the end region, and the skew angle θs1 is smaller than the skew angle θs2. In the axial direction, the end region is defined in the range including the coil side 525. The skew angle θs1 and the skew angle θs2 are tilt angles at which the conductors 523 are tilted with respect to the axial direction. The skew angle θs1 in the central region is preferably set in an appropriate angle range for reducing the harmonic component of the magnetic flux generated by the energization of the stator winding 521.

By reducing the skew angle of each conductor 523 in the stator winding 521 between the central region and the end region and making the skew angle θs1 in the central region smaller than the skew angle θs2 in the end region, the coil end 526 is reduced. It is possible to increase the winding coefficient of the stator winding 521 while achieving the above. In other words, it is possible to reduce the length of the coil end 526, that is, the length of the conductor wire that extends axially from the stator core 522, while ensuring a desired winding coefficient. This makes it possible to improve the torque while reducing the size of the rotary electric machine 500.

Here, an appropriate range for the skew angle θs1 in the central area will be described. When X conductors 523 are arranged in one magnetic pole in the stator winding 521, it is conceivable that the X-th harmonic component is generated by the energization of the stator winding 521. When the number of phases is S and the logarithm is m, X = 2 × S × m. Since the X-order harmonic component is a component that forms a composite wave of the X-1 order harmonic component and the X + 1 order harmonic component, the present disclosure discloses that the X-1 order harmonic component or the X + 1 order harmonic component. It was noted that the X-order harmonic component can be reduced by reducing at least one of the following harmonic components. Based on this attention, the present disclosure sets the skew angle θs1 within the angle range of “360 ° / (X + 1) to 360 ° / (X−1)” in terms of electrical angle to obtain the X-order harmonic component. It was found that

For example, when S = 3 and m = 2, the skew angle θs1 is set within the angular range of “360 ° / 13 to 360 ° / 11” to reduce the X = 12th harmonic component. That is, the skew angle θs1 may be set within the range of 27.7 ° to 32.7 °.

By setting the skew angle θs1 in the central region as described above, it is possible to positively interlink NS alternating magnet magnetic fluxes in the central region and increase the winding coefficient of the stator winding 521. be able to.

The skew angle θs2 in the end area is larger than the skew angle θs1 in the central area described above. In this case, the angle range of the skew angle θs2 is “θs1 <θs2 <90 °”.

Further, in the stator winding 521, the inner layer side conductive wire 523 and the outer layer side conductive wire 523 may be connected by welding or adhering ends of the respective conductive wires 523, or may be connected by bending. In the stator winding 521, the end of each phase winding is electrically connected to the power converter (inverter) via a bus bar or the like on one side (that is, one end side in the axial direction) of the coil ends 526 on both sides in the axial direction. It is configured to be connected to. Therefore, here, a configuration will be described in which the conductors are connected to each other at the coil end 526 while distinguishing between the coil end 526 on the bus bar connection side and the coil end 526 on the opposite side.

As a first configuration, each conductor 523 is connected by welding at the coil end 526 on the bus bar connection side, and each conductor 523 is connected by means other than welding at the coil end 526 on the opposite side. The means other than welding may be, for example, connection by bending the conductive wire material. At the coil end 526 on the bus bar connection side, it is assumed that the bus bar is connected to the end of each phase winding by welding. Therefore, by adopting a configuration in which each conductor 523 is connected by welding at the same coil end 526 as that, each welded portion can be performed in a series of steps, and work efficiency can be improved.

As a second configuration, the conductors 523 are connected by means other than welding at the coil end 526 on the bus bar connection side, and the conductors 523 are connected by welding at the coil end 526 on the opposite side. In this case, if the conductors 523 are connected by welding at the coil end 526 on the bus bar connection side, the distance between the bus bar and the coil end 526 is sufficiently large to avoid contact between the welded part and the bus bar. However, with this configuration, the distance between the bus bar and the coil end 526 can be reduced. As a result, it is possible to loosen the restriction on the length of the stator winding 521 in the axial direction or the bus bar.

③ As a third configuration, each wire 523 is connected by welding at the coil ends 526 on both sides in the axial direction. In this case, any of the conductive wire materials prepared before welding may have a short wire length, and the work efficiency can be improved by reducing the bending process.

The fourth configuration is to connect the conductors 523 at the coil ends 526 on both sides in the axial direction by means other than welding. In this case, the portion of the stator winding 521 where welding is performed can be reduced as much as possible, and it is possible to reduce the concern that insulation peeling will occur during the welding process.

Also, in the process of manufacturing the annular stator winding 521, it is preferable to manufacture a band-shaped winding arranged in a plane and then shape the band-shaped winding into a ring. In this case, it is advisable to weld the conductor wires at the coil end 526 to each other, if necessary, in the state of the flat strip winding. When the flat strip winding is formed into an annular shape, a cylindrical jig having the same diameter as that of the stator core 522 may be used to wind the strip winding around the cylindrical jig. Alternatively, the strip winding may be directly wound around the stator core 522.

The configuration of the stator winding 521 can be changed as follows.

For example, in the stator winding 521 shown in FIGS. 54 (a) and 54 (b), the skew angles of the central region and the end region may be the same.

In the stator winding 521 shown in FIGS. 54 (a) and 54 (b), the ends of the in-phase conducting wires 523 adjacent in the circumferential direction are connected to each other by a crossover portion extending in a direction orthogonal to the axial direction. May be

The number of layers of the stator windings 521 may be 2 × n layers (n is a natural number), and the stator windings 521 may have four layers, six layers or the like other than two layers.

Next, the inverter unit 530, which is a power conversion unit, will be described. Here, the configuration of the inverter unit 530 will be described with reference to FIGS. 56 and 57, which are exploded cross-sectional views of the inverter unit 530. 57, each member shown in FIG. 56 is shown as two subassemblies.

The inverter unit 530 includes an inverter housing 531, a plurality of electric modules 532 assembled in the inverter housing 531 and a bus bar module 533 that electrically connects the electric modules 532.

The inverter housing 531 includes a cylindrical outer wall member 541, an inner wall member 542 arranged radially inside the outer wall member 541 and a shaft of the inner wall member 542. It has a boss forming member 543 fixed to one end side in the direction. Each of these members 541 to 543 is preferably made of a conductive material, for example, carbon fiber reinforced plastic (CFRP). The inverter housing 531 is configured such that the outer wall member 541 and the inner wall member 542 are radially and inwardly and outwardly overlapped and combined, and the boss forming member 543 is attached to one end side of the inner wall member 542 in the axial direction. The assembled state is the state shown in FIG. 57.

A stator core 522 is fixed to the outer side of the outer wall member 541 of the inverter housing 531 in the radial direction. As a result, the stator 520 and the inverter unit 530 are integrated.

As shown in FIG. 56, the outer wall member 541 has a plurality of recesses 541a, 541b, 541c formed on the inner peripheral surface thereof, and the inner wall member 542 has a plurality of recesses 542a, 542b, 542c formed on the outer peripheral surface thereof. Are formed. The outer wall member 541 and the inner wall member 542 are assembled with each other, so that three hollow portions 544a, 544b, 544c are formed between them (see FIG. 57). Of these, the central hollow portion 544b is used as a cooling water passage 545 through which cooling water as a refrigerant flows. A sealant 546 is housed in the hollow portions 544a and 544c on both sides of the hollow portion 544b (cooling water passage 545). The sealing member 546 seals the hollow portion 544b (cooling water passage 545). The cooling water passage 545 will be described later in detail.

Further, the boss forming member 543 is provided with a disc ring-shaped end plate 547 and a boss portion 548 protruding from the end plate 547 toward the inside of the housing. The boss portion 548 is provided in a hollow cylindrical shape. For example, as shown in FIG. 51, the boss forming member 543 is a second end of the first end of the inner wall member 542 in the axial direction and the second end on the protruding side (that is, the vehicle inner side) of the rotating shaft 501 facing the first end. It is fixed to. 45 to 47, the base plate 405 is fixed to the inverter housing 531 (more specifically, the end plate 547 of the boss forming member 543).

The inverter housing 531 is configured to have a double peripheral wall in the radial direction around the axis, and the outer peripheral wall of the double peripheral wall is formed by the outer wall member 541 and the inner wall member 542 and the inner peripheral wall. Is formed by the boss portion 548. In the following description, the outer peripheral wall formed by the outer wall member 541 and the inner wall member 542 is also referred to as “outer peripheral wall WA1”, and the inner peripheral wall formed by the boss portion 548 is also referred to as “inner peripheral wall WA” 2.

An annular space is formed in the inverter housing 531 between the outer peripheral wall WA1 and the inner peripheral wall WA2, and a plurality of electric modules 532 are arranged side by side in the peripheral direction in the annular space. The electric module 532 is fixed to the inner peripheral surface of the inner wall member 542 by adhesion, screw fastening, or the like. In this embodiment, the inverter housing 531 corresponds to a “housing member”, and the electric module 532 corresponds to an “electric component”.

A bearing 560 is housed inside the inner peripheral wall WA2 (boss portion 548), and the rotary shaft 501 is rotatably supported by the bearing 560. The bearing 560 is a hub bearing that rotatably supports the wheel 400 at the center of the wheel. The bearing 560 is provided at a position that axially overlaps the rotor 510, the stator 520, and the inverter unit 530. In the rotating electric machine 500 of the present embodiment, the magnet unit 512 can be thinned according to the orientation in the rotor 510, and the slotless structure or the flat conductor structure is adopted in the stator 520, so that the magnetic circuit unit It is possible to reduce the thickness in the radial direction and expand the hollow space inside the magnetic circuit portion in the radial direction. This allows the magnetic circuit portion, the inverter unit 530, and the bearing 560 to be arranged in a radially stacked state. The boss portion 548 is a bearing holding portion that holds the bearing 560 inside thereof.

The bearing 560 is, for example, a radial ball bearing, and has an inner ring 561 having a tubular shape, an outer ring 562 having a tubular shape having a diameter larger than that of the inner ring 561 and arranged radially outside the inner ring 561, the inner ring 561 and the outer ring 561. And a plurality of balls 563 arranged between 562. The bearing 560 is fixed to the inverter housing 531 by assembling the outer ring 562 with the boss forming member 543, and the inner ring 561 is fixed to the rotating shaft 501. The inner ring 561, the outer ring 562 and the balls 563 are all made of a metal material such as carbon steel.

The inner ring 561 of the bearing 560 has a tubular portion 561a that houses the rotating shaft 501, and a flange 561b that extends from one axial end of the tubular portion 561a in a direction intersecting (orthogonal to) the axial direction. .. The flange 561b is a portion that comes into contact with the end plate 514 of the rotor carrier 511 from the inside, and is sandwiched by the flange 502 of the rotating shaft 501 and the flange 561b of the inner ring 561 when the bearing 560 is assembled to the rotating shaft 501. In this state, the rotor carrier 511 is held. In this case, the flange 502 of the rotating shaft 501 and the flange 561b of the inner ring 561 have the same angle of intersection with the axial direction (both are right angles in this embodiment), and are sandwiched between the respective flanges 502, 561b. The rotor carrier 511 is held in the opened state.

According to the configuration in which the rotor ring 511 is supported from the inside by the inner ring 561 of the bearing 560, the angle of the rotor carrier 511 with respect to the rotation shaft 501 can be maintained at an appropriate angle, and thus the parallelism of the magnet unit 512 with respect to the rotation shaft 501 can be improved. Can be kept. As a result, even in the configuration in which the rotor carrier 511 is expanded in the radial direction, it is possible to improve resistance to vibration and the like.

Next, the electric module 532 housed in the inverter housing 531 will be described.

The plurality of electric modules 532 are electric components such as a semiconductor switching element and a smoothing capacitor that form a power converter, and are divided into a plurality of modules, and the electric modules 532 are power elements. A switch module 532A having a semiconductor switching element and a capacitor module 532B having a smoothing capacitor are included.

As shown in FIGS. 49 and 50, a plurality of spacers 549 each having a flat surface for attaching the electric module 532 are fixed to the inner peripheral surface of the inner wall member 542, and the electric module 532 is attached to the spacer 549. There is. That is, since the inner peripheral surface of the inner wall member 542 is a curved surface, while the mounting surface of the electric module 532 is a flat surface, the spacer 549 forms a flat surface on the inner peripheral surface side of the inner wall member 542. The electric module 532 is fixed to the flat surface.

Note that the configuration in which the spacer 549 is interposed between the inner wall member 542 and the electric module 532 is not essential, and the inner peripheral surface of the inner wall member 542 may be a flat surface, or the mounting surface of the electric module 532 may be curved. It is also possible to attach the electrical module 532 directly to the member 542. It is also possible to fix the electric module 532 to the inverter housing 531 in a non-contact state with the inner peripheral surface of the inner wall member 542. For example, the electric module 532 is fixed to the end plate 547 of the boss forming member 543. The switch module 532A can be fixed to the inner peripheral surface of the inner wall member 542 in a contact state, and the capacitor module 532B can be fixed to the inner peripheral surface of the inner wall member 542 in a non-contact state.

When the spacer 549 is provided on the inner peripheral surface of the inner wall member 542, the outer peripheral wall WA1 and the spacer 549 correspond to the “cylindrical portion”. When the spacer 549 is not used, the outer peripheral wall WA1 corresponds to the “cylindrical portion”.

As described above, the outer peripheral wall WA1 of the inverter housing 531 is provided with the cooling water passage 545 through which the cooling water as the refrigerant flows. The cooling water flowing through the cooling water passage 545 cools each electric module 532. It has become. It is also possible to use cooling oil instead of cooling water as the refrigerant. The cooling water passage 545 is provided in an annular shape along the outer peripheral wall WA1, and the cooling water flowing in the cooling water passage 545 flows from the upstream side to the downstream side via each electric module 532. In the present embodiment, the cooling water passage 545 is provided annularly inside and outside in the radial direction so as to overlap each electric module 532 and surround each electric module 532.

The inner wall member 542 is provided with an inlet passage 571 through which cooling water flows into the cooling water passage 545 and an outlet passage 572 through which cooling water flows out from the cooling water passage 545. As described above, the plurality of electric modules 532 are fixed to the inner peripheral surface of the inner wall member 542, and in such a configuration, the interval between the electric modules adjacent to each other in the circumferential direction is expanded by only one place and the expansion thereof is increased. A part of the inner wall member 542 is projected inward in the radial direction to form a protruding portion 573 in the formed portion. The projecting portion 573 is provided with an inlet passage 571 and an outlet passage 572 arranged side by side along the radial direction.

FIG. 58 shows the arrangement of the electric modules 532 in the inverter housing 531. Note that FIG. 58 is the same vertical cross-sectional view as FIG.

As shown in FIG. 58, the electric modules 532 are arranged side by side in the circumferential direction such that the intervals between the electric modules in the circumferential direction are the first interval INT1 or the second interval INT2. The second interval INT2 is wider than the first interval INT1. The intervals INT1 and INT2 are, for example, distances between the center positions of two electric modules 532 that are adjacent to each other in the circumferential direction. In this case, the interval between the electric modules adjacent to each other in the circumferential direction without sandwiching the protrusion 573 is the first interval INT1, and the interval between the electric modules adjacent to each other in the circumferential direction with the protrusion 573 interposed is the second interval INT2. ing. That is, the interval between the electric modules adjacent to each other in the circumferential direction is partially widened, and the projecting portion 573 is provided at, for example, the central portion of the expanded interval (second interval INT2).

Each of the intervals INT1 and INT2 may be an arc distance between the center positions of two electric modules 532 that are circumferentially adjacent to each other on the same circle centered on the rotation axis 501. Alternatively, the intervals between the electric modules in the circumferential direction may be defined by angular intervals θi1 and θi2 about the rotation axis 501 (θi1 <θi2).

In the configuration shown in FIG. 58, the electric modules 532 arranged in the first interval INT1 are arranged in a state of being separated from each other in the circumferential direction (non-contact state), but instead of this configuration, the electric modules are arranged. 532 may be arranged so as to be in contact with each other in the circumferential direction.

As shown in FIG. 48, the end plate 547 of the boss forming member 543 is provided with a water passage port 574 in which passage end portions of an inlet passage 571 and an outlet passage 572 are formed. A circulation path 575 for circulating cooling water is connected to the inlet passage 571 and the outlet passage 572. The circulation path 575 includes a cooling water pipe. A pump 576 and a heat dissipation device 577 are provided in the circulation path 575, and the cooling water circulates through the cooling water passage 545 and the circulation path 575 when the pump 576 is driven. The pump 576 is an electric pump. The heat dissipation device 577 is, for example, a radiator that releases heat of cooling water to the atmosphere.

As shown in FIG. 50, since the stator 520 is arranged on the outer side of the outer peripheral wall WA1 and the electric module 532 is arranged on the inner side, the outer peripheral wall WA1 is covered with the stator 520 from the outer side. As heat is transferred, the heat of the electric module 532 is transferred from the inside. In this case, the stator 520 and the electric module 532 can be cooled at the same time by the cooling water flowing through the cooling water passage 545, and the heat of the heat generating component in the rotary electric machine 500 can be efficiently released.

Here, the electrical configuration of the power converter will be described with reference to FIG. 59.

As shown in FIG. 59, the stator winding 521 is composed of a U-phase winding, a V-phase winding and a W-phase winding, and the inverter 600 is connected to the stator winding 521. The inverter 600 is configured by a full bridge circuit having the same number of upper and lower arms as the number of phases, and a series connection body including an upper arm switch 601 and a lower arm switch 602 is provided for each phase. Each of these switches 601 and 602 is turned on / off by the drive circuit 603, and the winding of each phase is energized by the on / off. Each of the switches 601 and 602 is composed of a semiconductor switching element such as MOSFET or IGBT. In addition, a capacitor 604 for supplying a charge that supplies a charge required at the time of switching to each switch 601 and 602 is connected in parallel to the series connection body of the switches 601 and 602 to the upper and lower arms of each phase.

The control device 607 includes a microcomputer including a CPU and various memories, and performs energization control by turning on / off the switches 601 and 602 based on various detection information in the rotating electric machine 500 and requests for power running drive and power generation. .. The control device 607 performs on / off control of the switches 601 and 602 by PWM control at a predetermined switching frequency (carrier frequency) or rectangular wave control, for example. The control device 607 may be a built-in control device built in the rotary electric machine 500 or an external control device provided outside the rotary electric machine 500.

By the way, in the rotary electric machine 500 of the present embodiment, the electrical time constant is small because the inductance of the stator 520 is reduced, and under the circumstances where the electrical time constant is small, the switching frequency (carrier frequency ) Is high and the switching speed is fast. In this respect, since the charge supply capacitor 604 is connected in parallel to the series connection body of the switches 601 and 602 of each phase, the wiring inductance is reduced, and even if the switching speed is increased, an appropriate surge can be obtained. Measures can be taken.

The high potential side terminal of the inverter 600 is connected to the positive electrode terminal of the DC power source 605, and the low potential side terminal is connected to the negative electrode terminal (ground) of the DC power source 605. A smoothing capacitor 606 is connected in parallel to the DC power source 605 to the high potential side terminal and the low potential side terminal of the inverter 600.

The switch module 532A has switches 601 and 602 (semiconductor switching elements) as heat generating components, a drive circuit 603 (specifically, electric elements forming the drive circuit 603), and a capacitor 604 for supplying electric charge. Further, the capacitor module 532B has a smoothing capacitor 606 as a heat generating component. FIG. 60 shows a specific configuration example of the switch module 532A.

As shown in FIG. 60, the switch module 532A has a module case 611 as a housing case, and switches 601 and 602 for one phase housed in the module case 611, a drive circuit 603, and charge supply Capacitor 604. The drive circuit 603 is configured as a dedicated IC or a circuit board and provided in the switch module 532A.

The module case 611 is made of, for example, an insulating material such as resin, and is fixed to the outer peripheral wall WA1 with its side surface abutting the inner peripheral surface of the inner wall member 542 of the inverter unit 530. The module case 611 is filled with a molding material such as resin. In the module case 611, the switches 601, 602 and the drive circuit 603, and the switches 601, 602 and the capacitor 604 are electrically connected by a wiring 612, respectively. More specifically, the switch module 532A is attached to the outer peripheral wall WA1 via the spacer 549, but the spacer 549 is not shown.

In the state where the switch module 532A is fixed to the outer peripheral wall WA1, the closer to the outer peripheral wall WA1 in the switch module 532A, that is, the closer to the cooling water passage 545, the higher the cooling performance is. Therefore, the switches 601 and 602 are connected according to the cooling performance. The order of arrangement of the drive circuit 603 and the capacitor 604 is determined. Specifically, when comparing the heat generation amounts, the switches 601 and 602, the capacitor 604, and the drive circuit 603 are arranged in order from the largest heat generation amount. Therefore, the switches are arranged from the side closer to the outer peripheral wall WA1 according to the order of the heat generation amount. The capacitors 601 and 602, the capacitor 604, and the drive circuit 603 are arranged in this order. The contact surface of the switch module 532A is preferably smaller than the contactable surface of the inner peripheral surface of the inner wall member 542.

Although detailed illustration of the capacitor module 532B is omitted, in the capacitor module 532B, the capacitor 606 is housed in a module case having the same shape and size as the switch module 532A. Like the switch module 532A, the capacitor module 532B is fixed to the outer peripheral wall WA1 in a state where the side surface of the module case 611 is in contact with the inner peripheral surface of the inner wall member 542 of the inverter housing 531.

The switch module 532A and the capacitor module 532B do not necessarily have to be arranged concentrically inside the outer peripheral wall WA1 of the inverter housing 531 in the radial direction. For example, the switch module 532A may be arranged inside the capacitor module 532B in the radial direction, or may be arranged so as to be the opposite.

When the rotating electric machine 500 is driven, heat is exchanged between the switch module 532A and the condenser module 532B and the cooling water passage 545 through the inner wall member 542 of the outer peripheral wall WA1. Thereby, the switch module 532A and the condenser module 532B are cooled.

Each electric module 532 may be configured so that cooling water is drawn into the electric module 532 and cooling is performed by the cooling water inside the module. Here, the water cooling structure of the switch module 532A will be described with reference to FIGS. 61 (a) and 61 (b). 61A is a vertical cross-sectional view showing a cross-sectional structure of the switch module 532A in a direction crossing the outer peripheral wall WA1, and FIG. 61B is a cross-sectional view taken along line 61B-61B of FIG. 61A. ..

As shown in FIGS. 61A and 61B, the switch module 532A has a module case 611, switches 601 and 602 for one phase, a drive circuit 603, and a capacitor 604 as in FIG. In addition to this, it has a cooling device including a pair of piping portions 621 and 622 and a cooler 623. In the cooling device, the pair of pipe parts 621 and 622 are provided with an inflow side pipe part 621 through which cooling water flows from the cooling water passage 545 of the outer peripheral wall WA1 to the cooler 623, and from the cooler 623 to the cooling water passage 545. And a pipe portion 622 on the outflow side for outflowing. The cooler 623 is provided according to the object to be cooled, and the cooling device uses one or a plurality of stages of coolers 623. In the configuration of FIGS. 61 (a) and 61 (b), two stages of coolers 623 are provided in the direction away from the cooling water passage 545, that is, in the radial direction of the inverter unit 530 in a state of being separated from each other, and a pair of pipes is provided. Cooling water is supplied to the respective coolers 623 through the parts 621 and 622. The cooler 623 has a hollow inside, for example. However, inner fins may be provided inside the cooler 623.

In the configuration including the two-stage cooler 623, (1) the outer peripheral wall WA1 side of the first-stage cooler 623, (2) between the first-stage and second-stage coolers 623, and (3) the second-stage The outer peripheral wall side of the cooler 623 is a place for arranging the electric parts to be cooled, and these places are (2), (1), and (3) in descending order of cooling performance. There is. That is, the place between the two coolers 623 has the highest cooling performance, and in the place adjacent to any one cooler 623, the closer to the outer peripheral wall WA1 (cooling water passage 545), the higher the cooling performance. ing. In consideration of this, in the configurations shown in FIGS. 61A and 61B, the switches 601 and 602 are arranged between the coolers 623 of (2) the first stage and the second stage, and the condenser 604 is ( 1) It is arranged on the outer peripheral wall WA1 side of the first stage cooler 623, and the drive circuit 603 is arranged (3) on the opposite outer peripheral wall side of the second stage cooler 623. Although not shown, the drive circuit 603 and the capacitor 604 may be arranged in reverse.

In any case, in the module case 611, the switches 601, 602 and the drive circuit 603, and the switches 601, 602 and the capacitor 604 are electrically connected by the wiring 612, respectively. Further, since the switches 601 and 602 are located between the drive circuit 603 and the capacitor 604, the wiring 612 extending from the switches 601 and 602 toward the drive circuit 603 and the wiring 612 extending from the switches 601 and 602 toward the capacitor 604. Are relationships extending in opposite directions.

As shown in FIG. 61B, the pair of piping portions 621 and 622 are arranged side by side in the circumferential direction, that is, on the upstream side and the downstream side of the cooling water passage 545, and the piping portion on the inflow side located on the upstream side. Cooling water flows into the cooler 623 from 621, and then the cooling water flows out from the outflow side pipe portion 622 located on the downstream side. In order to promote the inflow of the cooling water to the cooling device, the cooling water passage 545 is provided at a position between the inflow side pipe portion 621 and the outflow side pipe portion 621 when viewed in the circumferential direction. It is advisable to provide a restriction unit 624 that restricts the flow. The restriction unit 624 may be a blocking unit that blocks the cooling water passage 545 or a throttle unit that reduces the passage area of the cooling water passage 545.

FIG. 62 shows another cooling structure of the switch module 532A. 62A is a vertical cross-sectional view showing a cross-sectional structure of the switch module 532A in a direction crossing the outer peripheral wall WA1, and FIG. 62B is a cross-sectional view taken along line 62B-62B of FIG. 62A. ..

In the configurations of FIGS. 62 (a) and 62 (b), as a difference from the configurations of FIGS. 61 (a) and 61 (b) described above, the arrangement of the pair of pipe portions 621 and 622 in the cooling device is different, and The piping portions 621 and 622 are arranged side by side in the axial direction. Further, as shown in FIG. 62 (c), in the cooling water passage 545, a passage portion communicating with the inflow side pipe portion 621 and an passage portion communicating with the outflow side pipe portion 622 are axially separated. The respective passage portions are communicated with each other through the pipe portions 621 and 622 and the coolers 623.

Besides, it is also possible to use the following configuration as the switch module 532A.

In the configuration shown in FIG. 63 (a), the cooler 623 is changed from two stages to one stage as compared with the configuration in FIG. 61 (a). In this case, the location where the cooling performance is highest in the module case 611 is different from that in FIG. 61A, and the location on the outer peripheral wall WA1 side is the most out of the radial sides of the cooler 623 (both sides in the horizontal direction in the figure). The cooling performance is high, then the cooling performance is lower in the order of the location on the side of the outer peripheral wall of the cooler 623 and the location away from the cooler 623. In consideration of this, in the configuration shown in FIG. 63 (a), the switches 601 and 602 are arranged at the outer peripheral wall WA1 side of both sides of the cooler 623 in the radial direction (both sides in the horizontal direction in the figure), and the condenser 604 is provided. The drive circuit 603 is arranged at a position on the side opposite to the outer peripheral wall of the cooler 623, and the drive circuit 603 is arranged at a position distant from the cooler 623.

Also, in the switch module 532A, it is possible to change the configuration in which the switches 601, 602 for one phase, the drive circuit 603, and the capacitor 604 are housed in the module case 611. For example, the configuration may be such that the switches 601 and 602 for one phase and one of the drive circuit 603 and the capacitor 604 are housed in the module case 611.

In FIG. 63 (b), a pair of piping parts 621 and 622 and a two-stage cooler 623 are provided in the module case 611, and the switches 601 and 602 are connected to the first and second coolers 623. The condenser 604 or the drive circuit 603 is arranged between them and is arranged on the outer peripheral wall WA1 side of the first stage cooler 623. Alternatively, the switches 601 and 602 and the drive circuit 603 may be integrated into a semiconductor module, and the semiconductor module and the capacitor 604 may be housed in the module case 611.

In FIG. 63 (b), in the switch module 532A, a condenser is arranged on the opposite side of the switches 601 and 602 in at least one of the coolers 623 arranged on both sides of the switches 601 and 602. It should have been done. That is, there is a configuration in which the condenser 604 is arranged only on one of the outer peripheral wall WA1 side of the first-stage cooler 623 and the opposite peripheral wall side of the second-stage cooler 623, or the condenser 604 is arranged on both sides. It is possible.

In the present embodiment, only the switch module 532A of the switch module 532A and the condenser module 532B is configured to draw the cooling water from the cooling water passage 545 into the module. However, the configuration may be changed so that the cooling water is drawn into the both modules 532A and 532B from the cooling water passage 545.

It is also possible to cool each electric module 532 by directly applying cooling water to the outer surface of each electric module 532. For example, as shown in FIG. 64, by embedding the electric module 532 in the outer peripheral wall WA1, cooling water is applied to the outer surface of the electric module 532. In this case, a part of the electric module 532 is immersed in the cooling water passage 545, or the cooling water passage 545 is expanded more radially than the structure of FIG. It is conceivable that the structure is soaked in. When the electric module 532 is immersed in the cooling water passage 545, the cooling performance can be further improved by providing fins in the module case 611 (the immersed portion of the module case 611) to be immersed.

Also, the electric module 532 includes a switch module 532A and a capacitor module 532B, and there is a difference in the amount of heat generated when the two are compared. In consideration of this point, it is possible to devise the arrangement of the electric modules 532 in the inverter housing 531.

For example, as shown in FIG. 65, a plurality of switch modules 532A are arranged in the circumferential direction without being dispersed, and are arranged on the upstream side of the cooling water passage 545, that is, on the side close to the inlet passage 571. In this case, the cooling water flowing from the inlet passage 571 is first used to cool the three switch modules 532A, and then used to cool each capacitor module 532B. In FIG. 65, the pair of piping portions 621 and 622 are arranged side by side in the axial direction as shown in FIGS. 62 (a) and 62 (b), but the configuration is not limited to this, and FIG. , (B), a pair of piping portions 621 and 622 may be arranged side by side in the circumferential direction.

Next, the configuration related to electrical connection in each electric module 532 and bus bar module 533 will be described. 66 is a sectional view taken along line 66-66 of FIG. 49, and FIG. 67 is a sectional view taken along line 67-67 of FIG. FIG. 68 is a perspective view showing the bus bar module 533 alone. Here, the configuration relating to the electrical connection of each electric module 532 and bus bar module 533 will be described by using these respective figures together.

As shown in FIG. 66, in the inverter housing 531 the circumferential direction of the projecting portion 573 provided on the inner wall member 542 (that is, the projecting portion 573 provided with the inlet passage 571 and the outlet passage 572 leading to the cooling water passage 545). The three switch modules 532A are arranged side by side in the circumferential direction at positions adjacent to each other, and the six capacitor modules 532B are further arranged side by side in the circumferential direction. As an outline, in the inverter housing 531, the inner side of the outer peripheral wall WA1 is divided into ten areas (that is, the number of modules + 1) in the circumferential direction, and one electric module 532 is arranged in each of the nine areas. In addition, the protruding portion 573 is provided in the remaining one region. The three switch modules 532A are a U-phase module, a V-phase module, and a W-phase module.

As shown in FIG. 66, the above-described FIG. 56, FIG. 57, etc., each electric module 532 (switch module 532A and capacitor module 532B) has a plurality of module terminals 615 extending from the module case 611. The module terminal 615 is a module input / output terminal for performing electrical input / output in each electric module 532. The module terminal 615 is provided so as to extend in the axial direction, and more specifically, is provided so as to extend from the module case 611 toward the inner side of the rotor carrier 511 (outside the vehicle) (FIG. 51). reference).

The module terminal 615 of each electric module 532 is connected to the bus bar module 533, respectively. The number of module terminals 615 differs between the switch module 532A and the capacitor module 532B. The switch module 532A is provided with four module terminals 615, and the capacitor module 532B is provided with two module terminals 615.

Further, as shown in FIG. 68, the bus bar module 533 extends from the annular portion 631 having an annular shape and extends from the annular portion 631, and enables connection with an external device such as a power supply device or an ECU (electronic control device). It has three external connection terminals 632 and a winding connection terminal 633 connected to the winding end of each phase in the stator winding 521. The bus bar module 533 corresponds to the “terminal module”.

The annular portion 631 is arranged inside the outer peripheral wall WA1 in the inverter housing 531 in the radial direction and on one side in the axial direction of each electric module 532. The annular portion 631 has, for example, an annular main body formed of an insulating member such as resin, and a plurality of bus bars embedded in the main body. The plurality of bus bars are connected to the module terminal 615 of each electric module 532, each external connection terminal 632, and each phase winding of the stator winding 521. The details will be described later.

The external connection terminal 632 includes a high-potential-side power terminal 632A and a low-potential-side power terminal 632B that are connected to the power supply device, and one signal terminal 632C that is connected to the external ECU. These external connection terminals 632 (632A to 632C) are arranged in a line in the circumferential direction, and are provided so as to extend in the axial direction inside the annular portion 631 in the radial direction. As shown in FIG. 51, when the bus bar module 533 is assembled in the inverter housing 531 together with the electric modules 532, one end of the external connection terminal 632 is configured to project from the end plate 547 of the boss forming member 543. .. Specifically, as shown in FIGS. 56 and 57, an insertion hole 547a is provided in the end plate 547 of the boss forming member 543, and a cylindrical grommet 635 is attached to the insertion hole 547a and the grommet 635 is attached. The external connection terminal 632 is provided in a state in which the 635 is inserted. Grommet 635 also functions as a sealed connector.

The winding connection terminal 633 is a terminal connected to the winding end portion of each phase of the stator winding 521, and is provided so as to extend radially outward from the annular portion 631. The winding connection terminals 633 are winding connection terminals 633U connected to the ends of the U-phase windings of the stator winding 521, winding connection terminals 633V connected to the ends of the V-phase windings, and W-phase windings. The ends of the wires have winding connection terminals 633W which are respectively connected to the connections. A current sensor 634 that detects the current (U-phase current, V-phase current, W-phase current) flowing through each winding connection terminal 633 and each phase winding may be provided (see FIG. 70).

The current sensor 634 may be arranged outside the electric module 532 and around each winding connection terminal 633, or may be arranged inside the electric module 532.

Here, the connection between each electric module 532 and the bus bar module 533 will be described more specifically with reference to FIGS. 69 and 70. FIG. 69 is a diagram showing each electric module 532 in a developed state in a plane and schematically showing an electrical connection state of each electric module 532 and the bus bar module 533. FIG. 70 is a diagram schematically showing the connection between the electric modules 532 and the bus bar module 533 in a state where the electric modules 532 are arranged in an annular shape. Note that, in FIG. 69, paths for power transmission are indicated by solid lines, and paths for signal transmission systems are indicated by alternate long and short dash lines. FIG. 70 shows only a path for power transmission.

The busbar module 533 has a first busbar 641, a second busbar 642, and a third busbar 643 as busbars for power transmission. Of these, the first bus bar 641 is connected to the power terminal 632A on the high potential side, and the second bus bar 642 is connected to the power terminal 632B on the low potential side. Further, the three third bus bars 643 are connected to the U-phase winding connection terminal 633U, the V-phase winding connection terminal 633V, and the W-phase winding connection terminal 633W, respectively.

Further, the winding connection terminal 633 and the third bus bar 643 are portions that easily generate heat due to the operation of the rotating electric machine 10. Therefore, a terminal block (not shown) may be interposed between the winding connection terminal 633 and the third bus bar 643, and the terminal block may be brought into contact with the inverter housing 531 having the cooling water passage 545. Alternatively, the winding connection terminal 633 and the third bus bar 643 may be bent in a crank shape to bring the winding connection terminal 633 and the third bus bar 643 into contact with the inverter housing 531 having the cooling water passage 545.

With such a configuration, the heat generated in the winding connection terminal 633 and the third bus bar 643 can be radiated to the cooling water in the cooling water passage 545.

In addition, in FIG. 70, the first bus bar 641 and the second bus bar 642 are illustrated as annular bus bars, but the bus bars 641 and 642 do not necessarily have to be connected in an annular shape, and are arranged in a circumferential direction. It may have a substantially C-shape in which the part is interrupted. Further, since each winding connection terminal 633U, 633V, 633W may be individually connected to the switch module 532A corresponding to each phase, each switch module 532A (actually, in actuality, not through the bus bar module 533. It may be configured to be connected to the module terminal 615).

On the other hand, each switch module 532A has four module terminals 615 consisting of a positive electrode side terminal, a negative electrode side terminal, a winding terminal and a signal terminal. Among them, the positive electrode side terminal is connected to the first bus bar 641, the negative electrode side terminal is connected to the second bus bar 642, and the winding terminal is connected to the third bus bar 643.

Further, the bus bar module 533 has a fourth bus bar 644 as a signal transmission system bus bar. The signal terminal of each switch module 532A is connected to the fourth bus bar 644, and the fourth bus bar 644 is connected to the signal terminal 632C.

In the present embodiment, the control signal for each switch module 532A is input from the external ECU via the signal terminal 632C. That is, the switches 601 and 602 in each switch module 532A are turned on / off by the control signal input via the signal terminal 632C. Therefore, each switch module 532A is configured to be connected to the signal terminal 632C without passing through the control device with a built-in rotating electric machine on the way. However, it is also possible to change this configuration so that a control device is built in the rotating electric machine and a control signal from the control device is input to each switch module 532A. Such a structure is shown in FIG.

The configuration of FIG. 71 has a control board 651 on which a control device 652 is mounted, and the control device 652 is connected to each switch module 532A. Further, a signal terminal 632C is connected to the control device 652. In this case, the control device 652 inputs a command signal regarding power running or power generation from, for example, an external ECU that is a host control device, and appropriately turns on / off the switches 601 and 602 of each switch module 532A based on the command signal.

In the inverter unit 530, the control board 651 may be arranged on the vehicle outer side (the inner side of the rotor carrier 511) than the bus bar module 533. Alternatively, the control board 651 may be arranged between each electric module 532 and the end plate 547 of the boss forming member 543. The control board 651 may be arranged such that at least a part of each of the electric modules 532 overlaps in the axial direction.

Further, each capacitor module 532B has two module terminals 615 consisting of a positive electrode side terminal and a negative electrode side terminal, the positive electrode side terminal is connected to the first bus bar 641, and the negative electrode side terminal is connected to the second bus bar 642. Has been done.

As shown in FIGS. 49 and 50, the inverter housing 531 is provided with a protrusion 573 having an inlet passage 571 and an outlet passage 572 of the cooling water in a position aligned with each electric module 532 in the circumferential direction. The external connection terminal 632 is provided so as to be adjacent to the protruding portion 573 in the radial direction. In other words, the protrusion 573 and the external connection terminal 632 are provided at the same angular position in the circumferential direction. In the present embodiment, the external connection terminal 632 is provided at a position on the radially inner side of the protruding portion 573. Further, when viewed from the inside of the inverter housing 531 in the vehicle, the water passage port 574 and the external connection terminal 632 are provided on the end plate 547 of the boss forming member 543 so as to be aligned in the radial direction (see FIG. 48).

In this case, by arranging the plurality of electric modules 532 together with the protruding portions 573 and the external connection terminals 632 in the circumferential direction, it is possible to reduce the size of the inverter unit 530 and the size of the rotating electric machine 500.

45 and 47 showing the structure of the wheel 400, the cooling pipe H2 is connected to the water channel port 574 and the electric wiring H1 is connected to the external connection terminal 632, and in this state, the electric wiring H1 and the cooling The piping H2 is housed in the housing duct 440.

In the above configuration, three switch modules 532A are arranged side by side in the circumferential direction in the inverter housing 531 next to the external connection terminal 632, and further, six capacitor modules 532B are arranged next to it in the circumferential direction. Although it is configured, this may be changed. For example, the configuration may be such that the three switch modules 532A are arranged side by side at a position farthest from the external connection terminal 632, that is, at a position on the opposite side with the rotary shaft 501 interposed therebetween. Further, it is possible to disperse the switch modules 532A so that the capacitor modules 532B are arranged on both sides of each of the switch modules 532A.

If each switch module 532A is arranged at the position farthest from the external connection terminal 632, that is, at the position on the opposite side across the rotary shaft 501, the mutual inductance between the external connection terminal 632 and each switch module 532A is set. It is possible to suppress malfunctions and the like caused by.

Next, the configuration of the resolver 660 provided as the rotation angle sensor will be described.

As shown in FIGS. 49 to 51, the inverter housing 531 is provided with a resolver 660 that detects the electrical angle θ of the rotating electric machine 500. The resolver 660 is an electromagnetic induction type sensor, and includes a resolver rotor 661 fixed to the rotating shaft 501 and a resolver stator 662 arranged radially outside of the resolver rotor 661 to face each other. The resolver rotor 661 has a disc ring shape and is provided coaxially with the rotary shaft 501 with the rotary shaft 501 inserted therethrough. The resolver stator 662 includes an annular stator core 663 and a stator coil 664 wound around a plurality of teeth formed on the stator core 663. The stator coil 664 includes a one-phase exciting coil and a two-phase output coil.

The excitation coil of the stator coil 664 is excited by a sinusoidal excitation signal, and the magnetic flux generated in the excitation coil by the excitation signal interlinks the pair of output coils. At this time, since the relative positional relationship between the exciting coil and the pair of output coils periodically changes according to the rotation angle of the resolver rotor 661 (that is, the rotation angle of the rotation shaft 501), the pair of output coils are interlinked. The number of magnetic fluxes generated changes periodically. In the present embodiment, the pair of output coils and the exciting coil are arranged such that the phases of the voltages generated in the pair of output coils are shifted from each other by π / 2. As a result, the output voltage of each of the pair of output coils becomes a modulated wave obtained by modulating the excitation signal with each of the modulated waves sin θ and cos θ. More specifically, when the excitation signal is “sinΩt”, the modulated waves are “sinθ × sinΩt” and “cosθ × sinΩt”, respectively.

The resolver 660 has a resolver digital converter. The resolver digital converter calculates the electrical angle θ by detection based on the generated modulated wave and excitation signal. For example, the resolver 660 is connected to the signal terminal 632C, and the calculation result of the resolver digital converter is output to the external device via the signal terminal 632C. Further, when the rotating electric machine 500 has a built-in control device, the calculation result of the resolver digital converter is input to the control device.

Here, the assembly structure of the resolver 660 in the inverter housing 531 will be described.

As shown in FIGS. 49 and 51, the boss portion 548 of the boss forming member 543 forming the inverter housing 531 has a hollow cylindrical shape, and the inner peripheral side of the boss portion 548 has a direction orthogonal to the axial direction. Is formed with a protrusion 548a. Then, the resolver stator 662 is fixed by a screw or the like in a state where the resolver stator 662 is in axial contact with the protruding portion 548a. Inside the boss portion 548, a bearing 560 is provided on one side in the axial direction with the protruding portion 548a interposed therebetween, and a resolver 660 is coaxially provided on the other side.

Further, the hollow portion of the boss portion 548 is provided with a projecting portion 548a on one side of the resolver 660 in the axial direction, and on the other side, a disk ring-shaped housing cover 666 that closes the accommodation space of the resolver 660. Is attached. The housing cover 666 is made of a conductive material such as carbon fiber reinforced plastic (CFRP). A hole 666a through which the rotary shaft 501 is inserted is formed in the center of the housing cover 666. In the hole 666a, a sealing material 667 that seals a space between the hole 666a and the outer peripheral surface of the rotating shaft 501 is provided. The resolver accommodating space is sealed by the sealing material 667. The sealing material 667 may be a sliding seal made of a resin material, for example.

The space in which the resolver 660 is housed is a space surrounded by the annular boss portion 548 in the boss forming member 543 and axially sandwiched by the bearing 560 and the housing cover 666, and the periphery of the resolver 660 is electrically conductive. Surrounded by material. As a result, the influence of electromagnetic noise on the resolver 660 can be suppressed.

Further, as described above, the inverter housing 531 has the double outer peripheral wall WA1 and the inner peripheral wall WA2 (see FIG. 57), and the outer side of the double peripheral wall (outer side of the outer peripheral wall WA1) is provided. A stator 520 is arranged, an electric module 532 is arranged between the double peripheral walls (between WA1 and WA2), and a resolver 660 is arranged inside the double peripheral walls (inside the inner peripheral wall WA2). There is. Since the inverter housing 531 is a conductive member, the stator 520 and the resolver 660 are arranged so as to be separated by a conductive partition wall (particularly a double conductive partition wall in this embodiment). It is possible to preferably suppress mutual magnetic interference between the child 520 side (magnetic circuit side) and the resolver 660.

Next, the rotor cover 670 provided on the open end side of the rotor carrier 511 will be described.

As shown in FIGS. 49 and 51, one side of the rotor carrier 511 in the axial direction is open, and a substantially disc ring-shaped rotor cover 670 is attached to the open end. The rotor cover 670 may be fixed to the rotor carrier 511 by an arbitrary joining method such as welding, adhesion, or screw fixing. It is more preferable that the rotor cover 670 has a portion that is dimensioned smaller than the inner circumference of the rotor carrier 511 so that the movement of the magnet unit 512 in the axial direction can be suppressed. The outer diameter of the rotor cover 670 matches the outer diameter of the rotor carrier 511, and the inner diameter of the rotor cover 670 is slightly larger than the outer diameter of the inverter housing 531. The outer diameter of the inverter housing 531 and the inner diameter of the stator 520 are the same.

As described above, the stator 520 is fixed to the outside of the inverter housing 531 in the radial direction, and at the joint portion where the stator 520 and the inverter housing 531 are joined to each other, the inverter housing 531 is axially attached to the stator 520. Protruding in the direction. A rotor cover 670 is attached so as to surround the protruding portion of the inverter housing 531. In this case, a seal material 671 is provided between the inner peripheral end surface of the rotor cover 670 and the outer peripheral surface of the inverter housing 531 to seal the gap between them. The housing space for the magnet unit 512 and the stator 520 is sealed by the sealing material 671. The sealing material 671 may be a sliding seal made of a resin material, for example.

According to this embodiment described in detail above, the following excellent effects can be obtained.

In the rotary electric machine 500, the outer peripheral wall WA1 of the inverter housing 531 is arranged radially inside the magnetic circuit portion including the magnet unit 512 and the stator winding 521, and the cooling water passage 545 is formed in the outer peripheral wall WA1. In addition, a plurality of electric modules 532 are arranged radially inside the outer peripheral wall WA1 along the outer peripheral wall WA1 in the circumferential direction. As a result, the magnetic circuit portion, the cooling water passage 545, and the power converter can be arranged so as to be laminated in the radial direction of the rotating electric machine 500, and efficient component arrangement is possible while reducing the dimension in the axial direction. Becomes Further, it is possible to efficiently cool the plurality of electric modules 532 that form the power converter. As a result, in the rotary electric machine 500, high efficiency and miniaturization can be realized.

An electric module 532 (switch module 532A, capacitor module 532B) having heat-generating components such as semiconductor switching elements and capacitors is provided in contact with the inner peripheral surface of the outer peripheral wall WA1. As a result, heat in each electric module 532 is transferred to the outer peripheral wall WA1, and the electric module 532 is appropriately cooled by heat exchange in the outer peripheral wall WA1.

In the switch module 532A, coolers 623 are arranged on both sides of the switches 601 and 602, respectively, and at least one cooler of the coolers 623 on both sides of the switches 601 and 602 is provided on the opposite side to the switches 601 and 602. The capacitor 604 is arranged. As a result, the cooling performance of the switches 601 and 602 can be improved, and the cooling performance of the condenser 604 can also be improved.

In the switch module 532A, the coolers 623 are arranged on both sides of the switches 601 and 602, respectively, and one of the coolers 623 on both sides of the switches 601 and 602 is driven on the opposite side to the switches 601 and 602. The circuit 603 is arranged, and the condenser 604 is arranged on the opposite side of the switches 601 and 602 in the other cooler 623. As a result, the cooling performance for the switches 601 and 602 can be improved, and the cooling performance for the drive circuit 603 and the condenser 604 can also be improved.

For example, in the switch module 532A, cooling water is introduced from the cooling water passage 545 into the module, and the cooling water is used to cool the semiconductor switching elements and the like. In this case, the switch module 532A is cooled by heat exchange by the cooling water inside the module in addition to the heat exchange by the cooling water at the outer peripheral wall WA1. This can enhance the cooling effect of the switch module 532A.

In the cooling system in which the cooling water flows into the cooling water passage 545 from the external circulation path 575, the switch module 532A is arranged on the upstream side near the inlet passage 571 of the cooling water passage 545, and the condenser module 532B is arranged in the switch module 532A. It is configured to be arranged on the downstream side. In this case, assuming that the cooling water flowing through the cooling water passage 545 has a lower temperature on the upstream side, it is possible to realize a configuration in which the switch module 532A is preferentially cooled.

A part of the interval between the electric modules adjacent to each other in the circumferential direction is expanded, and a projecting portion 573 having an inlet passage 571 and an outlet passage 572 is provided in a portion that becomes the expanded interval (second interval INT2). As a result, the inlet passage 571 and the outlet passage 572 of the cooling water passage 545 can be preferably formed in the portion on the radially inner side of the outer peripheral wall WA1. That is, it is necessary to secure the flow rate of the refrigerant in order to improve the cooling performance, and for that purpose, it is conceivable to increase the opening area of the inlet passage 571 and the outlet passage 572. In this respect, as described above, by partially expanding the interval between the electric modules and providing the protrusion 573, it is possible to preferably form the inlet passage 571 and the outlet passage 572 of a desired size.

The external connection terminals 632 of the bus bar module 533 are arranged at positions radially aligned with the protruding portion 573 on the radially inner side of the outer peripheral wall WA1. That is, the external connection terminal 632 is arranged together with the protrusion 573 in a portion (a portion corresponding to the second gap INT2) where the gap between the electric modules adjacent to each other in the circumferential direction is widened. As a result, the external connection terminals 632 can be preferably arranged while avoiding interference with the electric modules 532.

In the outer rotor type rotary electric machine 500, the stator 520 is fixed on the outer side of the outer peripheral wall WA1 in the radial direction, and the plurality of electric modules 532 are arranged on the inner side in the radial direction. As a result, the heat of the stator 520 is transmitted to the outer peripheral wall WA1 from the outer side in the radial direction, and the heat of the electric module 532 is transmitted from the inner side in the radial direction. In this case, the stator 520 and the electric module 532 can be simultaneously cooled by the cooling water flowing through the cooling water passage 545, and the heat of the heat generating member in the rotary electric machine 500 can be efficiently released.

The electric module 532 on the inner side in the radial direction and the stator winding 521 on the outer side in the radial direction with the outer peripheral wall WA1 sandwiched are electrically connected by the winding connection terminals 633 of the bus bar module 533. Further, in this case, the winding connection terminal 633 is provided at a position axially separated from the cooling water passage 545. As a result, even if the cooling water passage 545 is annularly formed in the outer peripheral wall WA1, that is, the inside and outside of the outer peripheral wall WA1 are divided by the cooling water passage 545, the electric module 532 and the stator winding 521 are separated. And can be suitably connected.

In the rotary electric machine 500 according to the present embodiment, by reducing or eliminating the teeth (iron core) between the conductors 523 arranged in the circumferential direction in the stator 520, the torque limitation caused by the magnetic saturation generated between the conductors 523 is limited. In addition to suppressing the above, the conductive wire 523 is made flat and thin to suppress the torque decrease. In this case, even if the outer diameter of the rotating electric machine 500 is the same, it is possible to expand the radially inner region of the magnetic circuit unit by thinning the stator 520, and use the inner region to cool the rotor. The outer peripheral wall WA1 having the water passage 545 and the plurality of electric modules 532 provided on the radially inner side of the outer peripheral wall WA1 can be suitably arranged.

In the rotary electric machine 500 of the present embodiment, the magnet magnetic flux gathers on the d-axis side in the magnet unit 512, so that the magnet magnetic flux on the d-axis is strengthened and the torque can be increased accordingly. In this case, as the radial thickness of the magnet unit 512 can be reduced (thinned), the radially inner region of the magnetic circuit portion can be expanded, and the inner region is used. Thus, the outer peripheral wall WA1 having the cooling water passage 545 and the plurality of electric modules 532 provided inside the outer peripheral wall WA1 in the radial direction can be suitably arranged.

Further, not only the magnetic circuit portion, the outer peripheral wall WA1 and the plurality of electric modules 532, but also the bearing 560 and the resolver 660 can be similarly preferably arranged in the radial direction.

The wheel 400 using the rotating electric machine 500 as an in-wheel motor is mounted on the vehicle body via a base plate 405 fixed to the inverter housing 531 and a mounting mechanism such as a suspension device. Here, since the rotating electric machine 500 has been downsized, it is possible to save space even when it is supposed to be mounted on a vehicle body. Therefore, it is possible to realize an advantageous configuration in expanding the installation area of a power supply device such as a battery and expanding the vehicle interior space in a vehicle.

Below, a modification of the in-wheel motor will be described.

(Modification 1 of in-wheel motor)
In the rotating electric machine 500, the electric module 532 and the bus bar module 533 are arranged inside the outer peripheral wall WA1 of the inverter unit 530 in the radial direction, and the electric module 532 and the bus bar are arranged inside and outside the outer peripheral wall WA1 in the radial direction. The module 533 and the stator 520 are arranged respectively. In such a configuration, the position of the bus bar module 533 with respect to the electric module 532 can be set arbitrarily. Further, when connecting each phase winding of the stator winding 521 and the bus bar module 533 across the outer peripheral wall WA1 in the radial direction, a winding connecting wire (for example, a winding connecting terminal 633) used for the connection is provided. The guidance position can be set arbitrarily.

That is, as the position of the bus bar module 533 with respect to the electric module 532, the configuration in which the (α1) bus bar module 533 is located outside the electric module 532 in the axial direction, that is, on the inner side on the rotor carrier 511 side,
(Α2) A configuration in which the bus bar module 533 is located inside the electric module 532 in the axial direction, that is, on the front side of the rotor carrier 511 side,
Can be considered.

Also, as the position for guiding the winding connection line,
(Β1) a configuration in which the winding connection line is guided outside the vehicle in the axial direction, that is, on the back side on the rotor carrier 511 side,
(Β2) a configuration in which the winding connecting wire is guided inside the vehicle in the axial direction, that is, on the front side of the rotor carrier 511 side,
Can be considered.

Below, four configuration examples regarding the arrangement of the electric module 532, the bus bar module 533, and the winding connection lines will be described with reference to FIGS. 72 (a) to 72 (d). 72 (a) to 72 (d) are vertical cross-sectional views showing a simplified configuration of the rotary electric machine 500, in which the configurations already described are denoted by the same reference numerals. The winding connection line 637 is an electrical wiring that connects each phase winding of the stator winding 521 and the bus bar module 533, and the winding connection terminal 633 described above corresponds to this, for example.

In the configuration of FIG. 72 (a), the position (α1) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the position (β1) is adopted as the position for guiding the winding connection wire 637. That is, the electric module 532, the bus bar module 533, the stator winding 521, and the bus bar module 533 are all connected outside the vehicle (on the inner side of the rotor carrier 511). Note that this corresponds to the configuration shown in FIG.

According to this configuration, the cooling water passage 545 can be provided in the outer peripheral wall WA1 without concern about interference with the winding connection wire 637. Further, the winding connecting wire 637 for connecting the stator winding 521 and the bus bar module 533 can be easily realized.

In the configuration of FIG. 72 (b), the above (α1) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above (β2) is adopted as the position for guiding the winding connection wire 637. That is, the electric module 532 and the busbar module 533 are connected outside the vehicle (the inner side of the rotor carrier 511), and the stator winding 521 and the busbar module 533 are inside the vehicle (the front side of the rotor carrier 511). It is configured to be connected with.

According to this configuration, the cooling water passage 545 can be provided in the outer peripheral wall WA1 without concern about interference with the winding connection wire 637.

In the configuration of FIG. 72 (c), the above (α2) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above (β1) is adopted as the position for guiding the winding connecting wire 637. That is, the electric module 532 and the bus bar module 533 are connected inside the vehicle (front side of the rotor carrier 511), and the stator winding 521 and the bus bar module 533 are outside the vehicle (back side of the rotor carrier 511). It is configured to be connected with.

In the configuration of FIG. 72 (d), the above (α2) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above (β2) is adopted as the position for guiding the winding connection wire 637. That is, the electric module 532, the bus bar module 533, the stator winding 521, and the bus bar module 533 are all connected inside the vehicle (front side of the rotor carrier 511).

According to the configurations of FIGS. 72 (c) and 72 (d), the bus bar module 533 is arranged inside the vehicle (on the front side of the rotor carrier 511) so that an electric component such as a fan motor is temporarily added. In that case, it is considered that the wiring becomes easy. Further, it is possible that the bus bar module 533 can be brought closer to the resolver 660 arranged on the vehicle inner side than the bearing, and wiring to the resolver 660 can be facilitated.

(Modification 2 of in-wheel motor)
A modified example of the mounting structure of the resolver rotor 661 will be described below. That is, the rotating shaft 501, the rotor carrier 511, and the inner ring 561 of the bearing 560 are rotating bodies that rotate integrally, and a modified example of the mounting structure of the resolver rotor 661 on the rotating bodies will be described below.

FIGS. 73 (a) to 73 (c) are configuration diagrams showing an example of a mounting structure of the resolver rotor 661 to the rotating body. In either configuration, the resolver 660 is surrounded by the rotor carrier 511, the inverter housing 531 and the like, and is provided in a closed space protected from water and mud from the outside. In FIG. 73 (a) among FIGS. 73 (a) to 73 (c), the bearing 560 has the same structure as in FIG. Further, in FIGS. 73 (b) and 73 (c), the bearing 560 has a configuration different from that of FIG. 49 and is arranged at a position away from the end plate 514 of the rotor carrier 511. In each of these drawings, two locations are illustrated as the mounting locations of the resolver rotor 661. Although the resolver stator 662 is not illustrated, for example, the boss portion 548 of the boss forming member 543 may be extended to the outer peripheral side of the resolver rotor 661 or the vicinity thereof, and the resolver stator 662 may be fixed to the boss portion 548. ..

In the configuration of FIG. 73 (a), a resolver rotor 661 is attached to the inner ring 561 of the bearing 560. Specifically, the resolver rotor 661 is provided on the axial end surface of the flange 561b of the inner ring 561 or on the axial end surface of the tubular portion 561a of the inner ring 561.

In the configuration of FIG. 73 (b), the resolver rotor 661 is attached to the rotor carrier 511. Specifically, the resolver rotor 661 is provided on the inner surface of the end plate 514 of the rotor carrier 511. Alternatively, in a configuration in which the rotor carrier 511 has the tubular portion 515 extending from the inner peripheral edge portion of the end plate 514 along the rotation axis 501, the resolver rotor 661 is provided on the outer peripheral surface of the tubular portion 515 of the rotor carrier 511. ing. In the latter case, the resolver rotor 661 is arranged between the end plate 514 of the rotor carrier 511 and the bearing 560.

In the configuration of FIG. 73 (c), a resolver rotor 661 is attached to the rotary shaft 501. Specifically, the resolver rotor 661 is provided on the rotary shaft 501 between the end plate 514 of the rotor carrier 511 and the bearing 560, or is opposite to the rotor carrier 511 with the bearing 560 being sandwiched on the rotary shaft 501. It is located on the side.

(Modification 3 of in-wheel motor)
Hereinafter, a modification of the inverter housing 531 and the rotor cover 670 will be described with reference to FIG. 74 (a) and 74 (b) are vertical cross-sectional views showing a simplified configuration of the rotary electric machine 500, in which the same reference numerals are given to the configurations already described. The configuration shown in FIG. 74 (a) substantially corresponds to the configuration described in FIG. 49 and the like, and the configuration shown in FIG. 74 (b) is a configuration obtained by partially modifying the configuration of FIG. 74 (a). Equivalent to.

In the configuration shown in FIG. 74 (a), a rotor cover 670 fixed to the open end of the rotor carrier 511 is provided so as to surround the outer peripheral wall WA1 of the inverter housing 531. That is, the inner diameter side end surface of the rotor cover 670 faces the outer peripheral surface of the outer peripheral wall WA1, and the seal material 671 is provided between them. Further, a housing cover 666 is attached to the hollow portion of the boss portion 548 of the inverter housing 531 and a seal material 667 is provided between the housing cover 666 and the rotary shaft 501. The external connection terminal 632 forming the bus bar module 533 penetrates the inverter housing 531 and extends to the inside of the vehicle (the lower side in the figure).

Further, the inverter housing 531 is provided with an inlet passage 571 and an outlet passage 572 which communicate with the cooling water passage 545, and a water passage port 574 including passage end portions of the inlet passage 571 and the outlet passage 572. ..

On the other hand, in the configuration shown in FIG. 74 (b), the inverter housing 531 (specifically, the boss forming member 543) is provided with the annular convex portion 681 extending to the protruding side (inside the vehicle) of the rotating shaft 501. A rotor cover 670 is provided so as to surround the convex portion 681 of the inverter housing 531. In other words, the end surface on the inner diameter side of the rotor cover 670 faces the outer peripheral surface of the convex portion 681, and the seal material 671 is provided between them. Further, the external connection terminals 632 forming the bus bar module 533 penetrate the boss portion 548 of the inverter housing 531 to extend into the hollow region of the boss portion 548, and penetrate the housing cover 666 to the inside of the vehicle (lower side in the figure). Extends to.

Further, the inverter housing 531 is formed with an inlet passage 571 and an outlet passage 572 which communicate with the cooling water passage 545. The inlet passage 571 and the outlet passage 572 extend into the hollow region of the boss portion 548, and have a relay pipe. It extends to the inside of the vehicle (lower side in the drawing) from the housing cover 666 via 682. In this configuration, the pipe portion extending from the housing cover 666 to the inside of the vehicle serves as the water channel port 574.

According to the configurations of FIGS. 74 (a) and 74 (b), the rotor carrier 511 and the rotor cover 670 are connected to the inverter while the internal space of the rotor carrier 511 and the rotor cover 670 is kept airtight. It can be suitably rotated with respect to the housing 531.

In particular, according to the configuration of FIG. 74 (b), the inner diameter of the rotor cover 670 is smaller than that of the configuration of FIG. 74 (a). Therefore, the inverter housing 531 and the rotor cover 670 are doubly provided in the axial direction at a position on the inner side of the vehicle with respect to the electric module 532, and an inconvenience due to electromagnetic noise of the electric module 532 is suppressed. can do. Further, by making the inner diameter of the rotor cover 670 small, the sliding diameter of the seal material 671 becomes small, and it is possible to suppress mechanical loss in the rotating sliding portion.

(Modification 4 of in-wheel motor)
Hereinafter, modified examples of the stator winding 521 will be described. FIG. 75 shows a modification of the stator winding 521.

As shown in FIG. 75, the stator winding 521 uses a conductor wire having a rectangular cross section, and is wound by corrugation with the long sides of the conductor wire extending in the circumferential direction. In this case, the conductor wires 523 of each phase, which are coil sides in the stator winding 521, are arranged at a predetermined pitch interval for each phase and are connected to each other at the coil ends. The conductor wires 523 adjacent to each other in the circumferential direction on the coil side are arranged such that their end faces in the circumferential direction are in contact with each other, or are closely arranged with a minute gap therebetween.

Also, in the stator winding 521, the conductor wire is bent in the radial direction for each phase at the coil end. More specifically, the stator winding 521 (conductor wire) is bent inward in the radial direction at different positions for each phase in the axial direction, whereby the U-phase, V-phase, and W-phase windings are wound. Interference with each other is avoided. In the configuration shown in the drawing, each phase winding is made to differ by the thickness of the conductor wire, and the conductor wire is bent at a right angle inward in the radial direction for each phase. It is preferable that the lengths of the conductors 523 arranged in the circumferential direction between both ends in the axial direction are the same for the conductors 523.

When the stator core 522 is assembled to the stator winding 521 and the stator 520 is manufactured, a part of the annular shape of the stator winding 521 is disconnected and disconnected (that is, the stator winding 521). It is advisable to make the stator winding 521 into an annular shape by assembling the stator core 522 to the inner peripheral side of the stator winding 521 and connecting the separated portions to each other.

In addition to the above, the stator core 522 is divided into a plurality (for example, three or more) in the circumferential direction, and a plurality of divided core pieces are provided on the inner peripheral side of the stator winding 521 formed in an annular shape. It is also possible to attach.

(Other modifications)
-For example, as shown in FIG. 50, in the rotary electric machine 500, the inlet passage 571 and the outlet passage 572 of the cooling water passage 545 are collectively provided at one place. However, this configuration is modified to include the inlet passage 571 and the outlet. The passage 572 may be provided at different positions in the circumferential direction. For example, the inlet passage 571 and the outlet passage 572 may be provided at positions different by 180 degrees in the circumferential direction, or at least one of the inlet passage 571 and the outlet passage 572 may be provided in plural.

In the wheel 400 of the above embodiment, the rotating shaft 501 is projected to one side in the axial direction of the rotating electric machine 500, but this may be changed and the rotating shaft 501 may be projected in both axial directions. Thereby, for example, a suitable configuration can be realized in a vehicle in which at least one of the front and rear of the vehicle has one wheel.

An inner rotor type rotating electric machine may be used as the rotating electric machine 500 used for the wheel 400.

(Modification 15)
In the above-described embodiment or modified example, in order to improve the cooling performance of the rotary electric machine 10, the magnet holder 41, the housing 30, the end plate 63, and the like may be modified as described below.

As shown in FIG. 76, when the magnet unit 42 of the rotor 40 is arranged to face the outer side of the stator winding 51 of the stator 50 in the radial direction, the coil end 55 is disposed on the inner surface of the end plate 63. The first facing surface of the facing end plate 63 is surface-treated to improve the emissivity (emissivity). Note that, in FIG. 76, the portion subjected to the surface processing is highlighted by a solid line. Examples of the surface treatment include alumite treatment (including black alumite treatment) and resin coating. In this modified example, the first facing surface includes the inner surface (bottom surface) 1063a of the end plate 63 that faces the coil end 55, without the shield, outside the coil end 55 in the axial direction. In this case, the end plate 63 corresponds to the cover member.

Also, of the outer surfaces of the end plate 63, the outer surface 1063b of the end plate 63 that faces the first facing surface in the axial direction is also similarly surface-treated to improve the emissivity.

Further, when the magnet unit 42 is arranged to face the stator winding 51, the second portion of the magnet holder 41, which faces the coil end 54, of the inner surface of the magnet holder 41 as a magnet holding portion. The facing surface is surface-treated to improve the emissivity. In this modification, on the second facing surface, the inner surface of the intermediate portion 45 (more specifically, the annular outer shoulder portion) that faces the coil end 54 on the axial outer side of the coil end 54 without the shield. The inner surface of 49b) 1045a is included. Further, in this modified example, the second facing surface includes the inner surface (inner peripheral surface) 1043a of the cylindrical portion 43 that faces the coil end 54 on the radially outer side of the coil end 54 without a shield. Be done.

Also, of the outer surfaces of the magnet holder 41, the outer surface facing the second facing surface is similarly surface-treated to improve the emissivity. In this modification, the outer surface facing the second facing surface includes the outer surface 1045b of the intermediate portion 45 axially facing the inner surface 1045a of the intermediate portion 45 serving as the second facing surface. Further, in this modified example, the outer surface (outer peripheral surface) of the cylindrical portion 43, which is radially opposed to the inner surface 1043a of the cylindrical portion 43 as the second opposed surface, is provided on the outer surface facing the second opposed surface. 1043b is included.

Note that the outer surface 1043b of the cylindrical portion 43 is surface-processed, so that the outer surface of the outer surface of the magnet holder 41 facing the inner surface to which the magnet unit 42 is fixed is also surface-processed. It will be.

Further, among the inner surfaces of the housing 30, a third facing surface facing the outer surface of the magnet holder 41 is surface-treated to improve the emissivity. In this modified example, the third facing surface includes the inner surface 1032a of the end surface 32 that faces the outer surface 1045b of the intermediate portion 45 on the axially outer side of the magnet holder 41 without a shield. In addition, in this modification, the inner surface (inner peripheral surface) 1031a of the peripheral wall 31 that faces the outer surface 1043b of the cylindrical portion 43 on the outer side in the radial direction of the magnet holder 41 without a shield is provided on the third opposing surface. Is included.

The inner surface 1031a of the peripheral wall 31 is also a first facing surface that faces the coil end 55 without a shield between the coil end 55 and the outside in the radial direction. Therefore, the housing 30 corresponds to a cover member.

The outer surface of the housing 30 facing the third facing surface is surface-treated to improve the emissivity. In this modification, the outer surface of the housing 30 facing the third facing surface includes the outer surface 1032b of the end surface 32 axially facing the inner surface 1032a of the end surface 32 as the third facing surface. In addition, in this modification, the outer surface of the housing 30 facing the third facing surface has an outer surface (an outer peripheral surface) of the peripheral wall 31 radially facing the inner surface 1031a of the peripheral wall 31 as the third facing surface. ) 1031b is included.

The outer surface 1031b of the peripheral wall 31 is also the outer surface of the housing 30 that faces the inner surface 1031a of the peripheral wall 31 as the first facing surface in the radial direction.

In summary, in this modified example, in the housing 30, the inner surface 1031a and the outer surface 1031b of the peripheral wall 31, and the inner surface 1032a and the outer surface 1032b of the end surface 32 are surface-treated. Further, in this modified example, in the magnet holder 41, the inner surface 1045a and the outer surface 1045b of the intermediate portion 45, and the inner surface 1043a and the outer surface 1043b of the cylindrical portion 43 are subjected to surface processing. Further, in this modified example, the inner surface 1063a and the outer surface 1063b of the end plate 63 are surface-processed.

According to this modification, it has the following excellent effects.

The inner surface 1063a of the end plate 63, which faces the coil end 55 in the axial direction, is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 55 can be efficiently absorbed and the coil end 55 can be efficiently cooled.

The outer surface 1063b of the end plate 63, which faces the inner surface 1063a, is also surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 55 can be absorbed through the inner surface 1063a of the end plate 63, passed through the inside of the end plate 63, and efficiently radiated to the outside from the outer surface 1063b of the end plate 63.

Similarly, the inner surface 1031a of the peripheral wall 31 that faces the coil end 55 in the radial direction is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 55 can be efficiently absorbed and the coil end 55 can be efficiently cooled.

The outer surface 1031b of the peripheral wall 31 facing the inner surface 1031a is also surface-treated to improve the emissivity. Therefore, radiant heat from the coil end 55 can be absorbed through the inner surface 1031a of the peripheral wall 31, transmitted inside the peripheral wall 31, and efficiently radiated to the outside from the outer surface 1031b of the peripheral wall 31.

The inner surface 1045a of the intermediate portion 45 axially opposed to the coil end 54 is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 54 can be efficiently absorbed and the coil end 54 can be efficiently cooled.

The outer surface 1045b of the intermediate portion 45, which faces the inner surface 1045a, is also surface-treated to improve the emissivity. At the same time, the inner surface 1032a of the end surface 32 of the housing 30 that faces the outer surface 1045b of the intermediate portion 45 in the axial direction and the outer surface 1032b that faces the inner surface 1032a are also surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 54 can be efficiently radiated to the outside of the housing 30 via the intermediate portion 45 and the end surface 32.

Also, the inner surface 1043a of the cylindrical portion 43, which faces the coil end 54 in the radial direction, is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 54 can be efficiently absorbed and the coil end 54 can be efficiently cooled.

Further, the outer surface 1043b of the cylindrical portion 43 facing the inner surface 1043a is also surface-treated to improve the emissivity. At the same time, the inner surface 1031a of the peripheral wall 31 of the housing 30 facing the outer surface 1043b of the cylindrical portion 43 in the axial direction and the outer surface 1031b facing the inner surface 1031a are also surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 54 can be efficiently radiated to the outside of the housing 30 via the cylindrical portion 43 and the peripheral wall 31.

Further, the outer surface 1043b of the cylindrical portion 43 having the magnet unit 42 fixed to the inner surface thereof, the inner surface 1031a of the peripheral wall 31 radially opposed to the outer surface 1043b, and the outer surface 1031b of the inner wall 1031a of the peripheral wall 31. Each is surface-treated. Therefore, the heat of the magnet unit 42 can be efficiently radiated to the outside of the housing 30.

A cooling water passage 74 is provided radially inside the coil side portion 53. Therefore, in the coil side portion 53, heat is radiated through the cooling water passage 74, and in the coil ends 54 and 55, as described above, to the outside of the housing 30 via the magnet holder 41, the housing 30, and the like. The heat will be dissipated efficiently. With the above configuration, the magnetic circuit such as the magnet unit 42 and the stator winding 51 can be efficiently cooled from inside and outside in the radial direction.

In this modification, the entire surface of each facing surface is surface-treated, but a part of the surface may be surface-treated. For example, of the inner surface of the peripheral wall 31, only the inner surface that faces the coil end 55 in the radial direction (the portion located outside the magnet holder 41 in the axial direction) may be subjected to the surface processing.

(Modification 16)
In the above-described embodiment or modified example, in order to improve the cooling performance of the rotary electric machine 500, the rotor carrier 511, the rotor cover 670, and the like may be modified as described below.

As shown in FIG. 77, when the magnet units 512 are arranged to face each other on the outer side in the radial direction of the stator winding 521, of the inner surface of the rotor cover 670, the rotor cover 670 that faces the coil end 526b is covered. The first facing surface is surface-treated to improve the emissivity (emissivity). Note that, in FIG. 77, the portion subjected to the surface processing is shown by a solid line. In this modification, the first facing surface includes the inner surface 1670a of the rotor cover 670, which faces the coil end 526b without the shield, on the axially outer side of the stator winding 521. The coil end 526b is disposed on the rotor cover 670 side in the axial direction of the coil end 526, and the coil end 526a is disposed on the end plate 514 side of the coil end 526 in the axial direction. It is arranged.

Also, of the outer surfaces of the rotor cover 670, the outer surface 1670b that faces the inner surface 1670a of the rotor cover 670 in the axial direction is also surface-treated to improve the emissivity.

Further, as shown in FIG. 77, when the magnet unit 512 is arranged to face the outer side of the stator winding 521 in the radial direction, the end plate 514 of the inner surface of the end plate 514 facing the coil end 526a is cut. The third facing surface is surface-treated to improve the emissivity. In this modified example, the third facing surface includes the inner surface 1514a of the end plate 514 that faces the coil end 526a, without the shield, outside the coil end 526a in the axial direction.

Also, of the outer surfaces of the end plate 514, the outer surface 1514b that faces the inner surface 1514a of the end plate 514 in the axial direction is also similarly surface-treated to improve the emissivity.

Further, of the outer surfaces of the cylindrical portion 513 to which the magnet unit 512 is fixed on the inner surface, the outer surface 1513b facing the inner surface on which the magnet unit 512 is fixed is also surface-treated.

In summary, in this modification, in the rotor carrier 511, the inner surface 1514a and the outer surface 1514b of the end plate 514 and the outer surface 1514b of the cylindrical portion 513 are surface-treated. In this modification, the rotor cover 670 has its inner surface 1670a and outer surface 1670b surface-treated.

According to this modification, it has the following excellent effects.

The inner surface 1670a of the rotor cover 670, which faces the coil end 526b in the axial direction, is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 526b can be efficiently absorbed and the coil end 526b can be efficiently cooled.

The outer surface 1670b of the rotor cover 670, which faces the inner surface 1670a, is also surface-treated to improve the emissivity. Therefore, radiant heat from the coil end 526b can be absorbed through the inner surface 1670a of the rotor cover 670, transmitted inside the rotor cover 670, and efficiently radiated to the outside from the outer surface 1670b of the rotor cover 670. it can.

Further, the inner surface 1514a of the end plate 514, which is axially opposed to the coil end 526a, is surface-treated to improve the emissivity. Therefore, the radiant heat from the coil end 526a can be efficiently absorbed and the coil end 526a can be efficiently cooled.

The outer surface 1514b of the end plate 514 facing the inner surface 1514a is also surface-treated to improve the emissivity. Therefore, radiant heat from the coil end 526a can be absorbed through the inner surface 1514a of the end plate 514, transmitted inside the end plate 514, and efficiently radiated to the outside from the outer surface 1514b of the end plate 514.

Also, the outer surface 1513b of the cylindrical portion 513 having the magnet unit 512 fixed to the inner surface is also surface-treated. Therefore, the heat of the magnet unit 512 can be efficiently radiated to the outside of the rotor carrier 511.

A cooling water passage 545 is provided inside the coil side 525 in the radial direction. Therefore, in the coil side 525, heat is efficiently radiated through the cooling water passage 545, and in the coil ends 526a and 526b, as described above, to the outside via the end plate 514, the rotor cover 670, and the like. The heat will be dissipated efficiently. Therefore, the entire stator winding 51 can be efficiently cooled.

In this modification, the entire surface of each facing surface is surface-treated, but a part of the surface may be surface-treated.

The disclosure in this specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations on them based on them. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure may have additional parts that may be added to the embodiments. The disclosure includes omissions of parts and / or elements of the embodiments. The disclosure includes replacements or combinations of parts and / or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. It is to be understood that some technical scopes disclosed are shown by the description of the claims and include meanings equivalent to the description of the claims and all modifications within the scope.

Although the present disclosure has been described according to the embodiments, it is understood that the present disclosure is not limited to the embodiments and the structure. The present disclosure also includes various modifications and modifications within an equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more, or less than those, also fall within the scope and spirit of the present disclosure.

Claims (12)

1. A field element (40, 510) having a magnet portion (42, 512) including a plurality of magnetic poles whose polarities alternate in the circumferential direction, and an armature (50 having a multi-phase armature winding (51, 521). , 520) and a cover member (30, 63, 670) that covers the field element and the armature, and one of the field element and the armature together with the rotating shaft (11, 501). A rotating electric machine (10,500),
   Of the inner surface of the cover member, the first facing surface that faces the coil ends (54, 55, 526a, 526b) of the armature winding has a surface processed to improve the emissivity. Electric machinery.
2. The field element is
   The magnet part has a cup-shaped magnet holding part (41, 511) fixed to the inner surface,
   It is fixed to the rotary shaft via the magnet holding portion and is configured to rotate together with the rotary shaft,
   The rotary electric machine according to claim 1, wherein a surface processing for improving emissivity is performed on a second facing surface of the inner surface of the magnet holding portion that faces the coil end of the armature winding.
3. The rotating electric machine according to claim 2, wherein an outer surface of the outer surface of the magnet holding portion facing the second facing surface is surface-treated to improve emissivity.
4. The rotating electric machine according to claim 2 or 3, wherein an outer surface of the outer surface of the magnet holding portion facing the inner surface to which the magnet portion is fixed is surface-treated to improve emissivity.
5. 5. The third facing surface of the inner surface of the cover member, which faces the outer surface of the magnet holding portion, is surface-treated to improve the emissivity. Rotating electric machine.
6. The rotating electric machine according to any one of claims 1 to 5, wherein an outer surface of the cover member facing the facing surface of the cover member is surface-treated to improve emissivity.
7. A plurality of electric components (532) constituting a power converter (600) electrically connected to the armature winding,
   A housing member (531) having a tubular portion (WA1, 549) provided inside the magnetic circuit portion including the magnet portion and the armature winding in the radial direction, to which the plurality of electric components are attached; Prepare,
   The cylindrical portion is provided with a refrigerant passage (545) for circulating a refrigerant,
   7. The housing member according to claim 1, wherein the plurality of electric components are arranged radially inside the tubular portion and circumferentially along the tubular portion. Rotating electric machine.
8. The magnet portion is configured such that the direction of the easy axis of magnetization on the side of the d-axis which is the center of the magnetic pole is parallel to the direction of the axis of easy magnetization on the side of the q-axis which is the magnetic pole boundary. The rotary electric machine according to any one of 1 to 7.
9. The rotating electric machine according to any one of claims 1 to 8, wherein the magnet has an intrinsic coercive force of 400 [kA / m] or more and a residual magnetic flux density of 1.0 [T] or more.
10. The armature winding has conductor portions (523) arranged at predetermined intervals in the circumferential direction at positions facing the magnet portion,
    In the armature,
    An inter-conductor member is provided between the conductor portions in the circumferential direction, and as the inter-conductor member, the circumferential width dimension of the inter-conductor member in one magnetic pole is Wt, the saturation magnetic flux density of the inter-conductor member is Bs, A configuration using a magnetic material or a non-magnetic material having a relationship of Wt × Bs ≦ Wm × Br, where Wm is the width of the magnet portion in the circumferential direction in one magnetic pole and Br is the residual magnetic flux density of the magnet portion. Or
    Or, it is configured such that no inter-conductor member is provided between the conductor portions in the circumferential direction,
    The rotary electric machine according to any one of claims 1 to 9, wherein a radial dimension of the conductor portion is smaller than a circumferential width dimension of one phase in one magnetic pole.
11. The armature winding has conductor portions (81, 82) arranged at predetermined intervals in the circumferential direction at positions facing the field element,
    The rotating electrical machine according to any one of claims 1 to 10, wherein the conductor wire portion has a radial thickness dimension smaller than a circumferential width dimension of one phase in one magnetic pole.
12. The armature winding has conductor portions (81, 82) arranged at predetermined intervals in the circumferential direction at positions facing the field element,
    Each of the conducting wires forming the conducting wire portion is a bundle of a plurality of strands (86), and is a strand assembly in which the resistance value between the bundled strands is larger than the resistance value of the strand itself. The rotating electric machine according to any one of claims 1 to 11.

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