JP2020137143A - Rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine capable of inhibiting flapping at a bearing.SOLUTION: A rotary electric machine 500 comprises: a rotor 510 fixed rotatably around a rotation shaft 501; and a stator 520 disposed so as to face the rotor 510 in the radial direction. The rotary electric machine 500 also comprises: a first bearing 1001 that rotatably supports the rotation shaft 501 of the rotor 510; and a second bearing 1002. The second bearing 1002 is disposed at a position apart from the rotor 510's centroid G100 in an axial direction as compared with the first bearing 1001; an outer diameter of an outer ring 1022 of the second bearing 1002 is configured larger than an outer diameter of an outer ring 1021 of the first bearing 1001.SELECTED DRAWING: Figure 76

Description

The present invention relates to a rotary electric machine.

In a rotary electric machine, it is generally practiced to rotatably support the rotating shaft by a pair of bearings separated in the axial direction (for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2014-213622 JP-A-2018-27007

By the way, the center of gravity of the rotary electric machine is not always in the middle of the pair of bearings in the axial direction. In particular, when it is used as an in-wheel motor like the rotary electric machine of Patent Document 1, it is fixed to the brake disc, so that the center of gravity is likely to be biased toward the brake disc side.

If the center of gravity is biased to either side of the pair of bearings, there is a problem that fluttering is likely to occur in the bearing on the side away from the center of gravity.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotary electric machine capable of suppressing fluttering in a bearing.

The first means for solving the above-mentioned problems is a rotary electric machine including a rotor rotatably fixed about a rotation axis and a stator arranged so as to face the rotor in the radial direction. The first bearing and the second bearing that rotatably support the rotating shaft of the rotor are provided, and the second bearing is axially oriented from the center of gravity of the rotor as compared with the first bearing. The outer diameter of the outer ring of the second bearing is at least larger than the outer diameter of the outer ring of the first bearing.

The outer diameter of the outer ring of the second bearing, which is fixed at a location far from the center of gravity and where large axial shake is likely to occur due to centrifugal force, has been increased. As a result, the number of rolling elements of the second bearing increases, or the contact area of the sliding surface increases. Therefore, the second bearing can suitably receive the load, suppress the shaft shake, and preferably suppress the vibration and fluttering.

The second means is that, in the first means, the stator has a cylindrical bearing holding portion, and the second bearing is fixed to the inner peripheral surface of the bearing holding portion. The coefficient of linear expansion of the holding portion and the coefficient of linear expansion of the second bearing are the same.

With the above configuration, even if the temperature changes due to heat generation or the like, the bearing holding portion and the second bearing expand to the same extent, so that loosening or rattling between the bearing holding portion and the second bearing is suppressed. it can.

The third means, in the first or second means, the rotary electric machine includes an electric module, the rotor has a tubular rotor carrier, and the stator holds a tubular bearing. The second bearing is fixed to the inner peripheral surface of the bearing holding portion, and the electric module is fixed to the stator in a state of being housed inside the rotor carrier. The first bearing and the second bearing are arranged radially inside the electric module, and the bearing holding portion is separated from the electric module in the radial direction.

Since the bearing holding portion and the electric module are separated from each other, it is possible to prevent the second bearing and the heating element called the electric module from coming into contact with each other. Further, since a fluid such as air flows between the second bearing and the electric module, the cooling performance is excellent. Further, by arranging the second bearing inside the electric module in the radial direction, the length of the rotary electric machine in the axial direction can be suppressed.

In any of the first to third means, the fourth means is such that the front rotor has a tubular rotor carrier, and the stator is arranged inside the rotor carrier. The rotating shaft is fixed to an end plate provided on one end side in the axial direction of the rotor carrier, and the second bearing is axially oriented from the end plate as compared with the first bearing. Are separated from each other.

As a result, in the axial direction, the first bearing having a small diameter can be arranged and then the second bearing having a large diameter can be arranged, and the assembling property is improved as compared with the case where the bearings are arranged in the opposite direction. ..

In the fifth means, in the fourth means, a rotation angle sensor for detecting the rotation angle of the rotation shaft is fixed to the rotation shaft, and the second bearing is the first bearing in the axial direction. It is arranged in the vicinity of the rotation angle sensor as compared with.

Since vibration is further suppressed by the second bearing as compared with the first bearing, the detection accuracy of the rotation angle sensor can be improved.

The sixth means is any one of the first to fifth means, wherein the rotor includes a rotor carrier and a magnet portion fixed to the rotor carrier, and the center of gravity of the rotor is set. , At least the rotor carrier, the magnet portion, and the rotation axis are taken into consideration in the calculation.

In any of the first to sixth means, the seventh means is such that a braking device for braking the rotation of the rotor is fixed to the rotating electric machine, and the center of gravity of the rotor is the rotation. The calculation is made in consideration of the braking device fixed to the child.

When the braking device is fixed to the rotor, the center of gravity of the rotor may shift depending on the position of the center of gravity of the braking device. By considering this deviation, the arrangement and size of the bearing can be appropriately performed.

Vertical cross-sectional perspective view of a rotary electric machine. Vertical sectional view of a rotary electric machine. FIG. 2 is a sectional view taken along line III-III of FIG. FIG. 3 is an enlarged cross-sectional view showing a part of FIG. Exploded view of the rotary electric machine. Exploded view of the inverter unit. A torque diagram showing the relationship between the ampere turn of the stator winding and the torque density. Cross-sectional view of the rotor and stator. The figure which shows the part of FIG. 8 enlarged. Cross-sectional view of the stator. Longitudinal section of the stator. Perspective view of the stator winding. The perspective view which shows the structure of the conducting wire. The schematic diagram which shows the structure of a wire. The figure which shows the form of each lead wire in the nth layer. A side view showing each lead wire of the nth layer and the n + 1th layer. The figure which shows the relationship between the electric angle and the magnetic flux density about the magnet of an embodiment. The figure which shows the relationship between the electric angle and the magnetic flux density about the magnet of the comparative example. Electrical circuit diagram of the control system of the rotary electric machine. The functional block diagram which shows the current feedback control processing by a control device. The functional block diagram which shows the torque feedback control processing by a control device. The cross-sectional view of the rotor and the stator in the second embodiment. FIG. 22 is an enlarged view showing a part of FIG. 22. The figure which shows concretely the flow of magnetic flux in a magnet unit. FIG. 3 is a cross-sectional view of the stator in the first modification. FIG. 3 is a cross-sectional view of the stator in the first modification. FIG. 3 is a cross-sectional view of the stator in the second modification. The cross-sectional view of the stator in the modification 3. FIG. 5 is a cross-sectional view of the stator in the modified example 4. The cross-sectional view of the rotor and the stator in the modification 7. FIG. 5 is a functional block diagram showing a part of processing of the operation signal generation unit in the modification 8. The flowchart which shows the procedure of the carrier frequency change processing. The figure which shows the connection form of each lead wire which constitutes a lead wire group in the modification 9. The figure which shows the structure which four pairs of lead wires are laminated and arranged in the modification 9. FIG. 5 is a cross-sectional view of the inner rotor type rotor and stator in the modified example 10. The figure which shows the part of FIG. 35 enlarged. A vertical sectional view of an inner rotor type rotary electric machine. The vertical sectional view which shows the schematic structure of the inner rotor type rotary electric machine. The figure which shows the structure of the rotary electric machine of the inner rotor structure in the modification 11. The figure which shows the structure of the rotary electric machine of the inner rotor structure in the modification 11. The figure which shows the structure of the rotary armature type rotary electric machine in the modification 12. FIG. 5 is a cross-sectional view showing the configuration of the conducting wire in the modified example 14. The figure which shows the relationship between reluctance torque, magnet torque and DM. The figure which shows the teeth. The perspective view which shows the wheel of an in-wheel motor structure and its peripheral structure. A vertical sectional view of a wheel and its peripheral structure. An exploded perspective view of the wheel. A side view of the rotary electric machine as viewed from the protruding side of the rotary shaft. FIG. 48 is a sectional view taken along line 49-49. 50-50 sectional view of FIG. 49. An exploded sectional view of a rotary electric machine. Partial sectional view of the rotor. Perspective view of the stator winding and the stator core. The front view which shows the stator winding developed in a plane. The figure which shows the skew of a lead wire. An exploded sectional view of the inverter unit. An exploded sectional view of the inverter unit. The figure which shows the state of arrangement of each electric module in an inverter housing. A circuit diagram showing the electrical configuration of a power converter. The figure which shows the cooling structure example of a switch module. The figure which shows the cooling structure example of a switch module. The figure which shows the cooling structure example of a switch module. The figure which shows the cooling structure example of a switch module. The figure which shows the cooling structure example of a switch module. The figure which shows the arrangement order of each electric module with respect to a cooling water passage. FIG. 49 is a sectional view taken along line 66-66 of FIG. FIG. 49 is a sectional view taken along line 67-67 of FIG. The perspective view which shows the bus bar module alone. The figure which shows the electrical connection state of each electric module and a bus bar module. The figure which shows the electrical connection state of each electric module and a bus bar module. The figure which shows the electrical connection state of each electric module and a bus bar module. The block diagram for demonstrating the modification 1 in the in-wheel motor. The block diagram for demonstrating the modification 2 in the in-wheel motor. The block diagram for demonstrating the modification 3 in the in-wheel motor. The block diagram for demonstrating the modification 4 in the in-wheel motor. The block diagram for demonstrating the modification 5 in the in-wheel motor. The block diagram for demonstrating the modification 6 in the in-wheel motor.

A plurality of embodiments will be described with reference to the drawings. In a plurality of embodiments, functionally and / or structurally corresponding parts and / or associated parts may be designated with the same reference code or reference codes having a hundreds or more different digits. For corresponding and / or associated parts, the description of other embodiments can be referred to.

The rotary electric machine in the present embodiment is used, for example, as a vehicle power source. However, the rotary electric machine can be widely used for industrial use, vehicle use, home appliance use, OA equipment use, game machine use, and the like. In each of the following embodiments, parts that are the same or equal to each other are designated by the same reference numerals in the drawings, and the description thereof will be incorporated for the parts having the same reference numerals.

(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 (abduction structure). The outline of the rotary electric machine 10 is shown in FIGS. 1 to 5. FIG. 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 in a direction along the rotation axis 11, and FIG. 3 is a direction orthogonal to the rotation axis 11. It is a cross-sectional view of the rotary electric machine 10 (cross-sectional view taken along line III-III in FIG. 2), FIG. 4 is an enlarged cross-sectional view of a part of FIG. 3, and FIG. 5 is an exploded view of the rotary electric machine 10. Is. In FIG. 3, for convenience of illustration, the hatching indicating the cut surface is omitted except for the rotating shaft 11. In the following description, the direction in which the rotating shaft 11 extends is the axial direction, the direction extending radially from the center of the rotating shaft 11 is the radial direction, and the direction extending circumferentially around the rotating shaft 11 is the circumferential direction.

The rotary electric machine 10 is roughly classified into a bearing unit 20, a housing 30, a rotor 40, a stator 50, and an inverter unit 60. Each of these members is arranged coaxially with the rotating shaft 11 and is assembled in the axial direction in a predetermined order to form the rotating electric machine 10. The rotary electric machine 10 of the present embodiment has a configuration having a rotor 40 as a "field magnet" and a stator 50 as an "armature", and is embodied as a rotary field type rotary electric machine. It has become a thing.

The bearing unit 20 has two bearings 21 and 22 arranged apart from each other in the axial direction, and a holding member 23 for holding the bearings 21 and 22. The bearings 21 and 22 are, for example, radial ball bearings, each of which has 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 bearings 21 and 22 are assembled inside the holding member 23 in the radial direction. The rotating shaft 11 and the rotor 40 are rotatably supported inside the bearings 21 and 22 in the radial direction. The bearings 21 and 22 form a set of bearings that rotatably support the rotating shaft 11.

In the bearings 21 and 22, the balls 27 are held by retainers (not shown), and the pitch between the balls is maintained in that state. The bearings 21 and 22 have sealing members at the upper and lower portions in the axial direction of the retainer, and the inside thereof is filled with non-conductive grease (for example, non-conductive urea-based grease). Further, the position of the inner ring 26 is mechanically held by the spacer, and a constant pressure preload that is convex in the vertical direction from the inside is applied.

The housing 30 has a cylindrical peripheral wall 31. The peripheral wall 31 has a first end and a second end facing 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 open throughout the 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 fixture such as a screw or a rivet in a state of being inserted into the hole 34. Further, a hollow cylindrical rotor 40 and a hollow cylindrical stator 50 are housed in the housing 30, that is, in the internal space partitioned 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 a stator 50 is arranged inside the housing 30 in the radial direction of the cylindrical rotor 40. The rotor 40 is cantilevered by the rotating shaft 11 on the side of the end face 32 in the axial direction.

The rotor 40 has a magnet holder 41 formed in a hollow tubular 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 has a cylindrical portion 43 having a cylindrical shape, an attachment 44 having a cylindrical shape and a diameter smaller than that of the cylindrical portion 43, and an intermediate portion serving as a portion connecting the cylindrical portion 43 and the fixed portion 44. It has 45 and. A magnet unit 42 is attached to the inner peripheral surface of the cylindrical portion 43.

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

The rotating shaft 11 is inserted through the through hole 44a of the fixing portion 44. The fixing portion 44 is fixed to the rotating 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 coupling, key coupling, welding, caulking, or the like using unevenness. As a result, the rotor 40 rotates integrally with the rotating shaft 11.

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

The rotor 40 is provided with a fixing portion 44 only on one of its two axially opposed ends, whereby the rotor 40 is cantilevered and supported by the rotating shaft 11. Here, the fixing portion 44 of the rotor 40 is rotatably supported by bearings 21 and 22 of the bearing unit 20 at two positions different in the axial direction. That is, the rotor 40 is rotatably supported by two bearings 21 and 22 which are separated from each other in the axial direction at one of the two end portions of the magnet holder 41 which face each other in the axial direction. Therefore, even if the rotor 40 is cantilevered and supported by the rotating shaft 11, stable rotation of the rotor 40 can be 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 ball 27. The dimensions are different. 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, even if vibration of the rotor 40 or vibration due to imbalance caused by component tolerance acts on the bearing unit 20 on the side closer to the center of the rotor 40, the influence of the vibration or vibration is well absorbed. Tolerant. Specifically, by increasing the play dimension (gap dimension) by preloading the bearing 22 near the center of the rotor 40 (lower side of the figure), the vibration generated in the cantilever structure is absorbed by the play portion. To. The preload may be either 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 bonding. Here, the preload can be generated 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. Preload can also be generated by arranging the outer ring 25 of the bearing 22 at different positions in the axial direction with respect to the inner ring 26 of the bearing 22.

When a constant pressure preload is adopted, a preload spring, for example, a wave washer 24 or the like is bearing so that a preload is generated from the region 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 sandwiched between the 22 and the bearing 21. Also in this case, 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 bonding. The bearing 21 or the outer ring 25 of the bearing 22 is arranged with respect to the holding member 23 via a predetermined clearance. 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, when this force is transmitted through the rotating shaft 11, a force that presses the inner ring 26 of the bearing 21 in the direction of the bearing 22 acts. As a result, the positions of the outer ring 25 and the inner ring 26 in the axial direction of both the bearings 21 and 22 are displaced, and the preload can be applied to the two bearings in the same manner as the above-mentioned fixed position preload.

When generating the constant pressure preload, it is not always necessary to apply the spring force to the outer ring 25 of the bearing 22 as shown in FIG. For example, a spring force may be applied to the outer ring 25 of the bearing 21. Further, the inner ring 26 of any of the bearings 21 and 22 is arranged with respect to the rotating shaft 11 via a predetermined clearance, and the outer ring 25 of the bearings 21 and 22 is press-fitted or bonded to the holding member 23. Preload may be applied to the two bearings 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 direction in which the preload is generated is applied to the mechanism for generating the preload, and a target to which the preload is applied. The direction of gravity on an object may fluctuate. Therefore, when applying the rotary electric machine 10 to a vehicle, it is desirable to adopt a 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 in the radial direction of the intermediate portion 45. That is, the cylindrical portion 43 protrudes outward in the axial direction from the base end portion (lower end portion on the lower side of the figure) of the fixed portion 44. In this configuration, the rotor 40 can be supported with respect to the rotating shaft 11 at a position near the center of gravity of the rotor 40, as compared with the case where the intermediate portion 45 is provided in a flat plate shape without a step. The stable operation of 40 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 fixing portion 44 in the radial direction and is inward of the intermediate portion 45. Is formed in an annular shape, and a coil accommodating recess for accommodating the coil end 54 of the stator winding 51 of the stator 50, which will be described later, at a position surrounding the bearing accommodating recess 46 in the radial direction and being outside the intermediate portion 45. 47 is formed. The accommodating 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 in and out in the radial direction. This makes it possible to shorten the axial length dimension in the rotary electric machine 10.

The intermediate portion 45 is provided so as to project radially outward from the rotation shaft 11 side. A contact avoiding portion extending in the axial direction and avoiding contact of the stator winding 51 of the stator 50 with the coil end 54 is provided in the intermediate portion 45. The intermediate portion 45 corresponds to the overhanging 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 be in consideration of assembly with the rotor 40. Assuming that the stator 50 is assembled radially inward of the rotor 40, it is preferable that the coil end 54 is bent inward in the radial direction on the insertion tip side with respect to 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 sufficient space is preferable in manufacturing.

Further, the magnet unit 42 as the magnet portion is composed of a plurality of permanent magnets arranged so as to alternately change the polarities 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, the 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 radially inside the stator winding. The wire 51 is arranged so as to face the annular magnet unit 42 with a predetermined air gap in between. The stator winding 51 is composed of a plurality of phase windings. Each of these phase windings is configured by connecting a plurality of conductors arranged in the circumferential direction to each other at a predetermined pitch. In the present embodiment, a U-phase, V-phase, and W-phase three-phase winding and an X-phase, Y-phase, and Z-phase three-phase winding are used, and two of these three-phase windings are used. The stator winding 51 is configured as a 6-phase phase winding.

The stator core 52 is formed in an annular shape by laminated steel plates on which electromagnetic steel plates 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 in which about several% (for example, 3%) of silicon is added to iron. The stator winding 51 corresponds to the armature winding, and the stator core 52 corresponds to the armature core.

The stator winding 51 is a portion that overlaps the stator core 52 in the radial direction, and is a coil side portion 53 that is radially outside the stator core 52, and one end side of the stator core 52 and others in the axial direction. It has coil ends 54 and 55 overhanging on the end side, respectively. The coil side portion 53 faces the stator core 52 and the magnet unit 42 of the rotor 40 in the radial direction, respectively. When the stator 50 is arranged inside the rotor 40, the coil end 54 on the side of the bearing unit 20 (upper side in the figure) of the coil ends 54 and 55 on both sides in the axial direction is the magnet holder of the rotor 40. It is housed in the coil accommodating recess 47 formed by 41. However, the details of the stator 50 will be described later.

The inverter unit 60 has a unit base 61 fixed to the housing 30 by fasteners such as bolts, and a plurality of electrical 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 the casing 64 is formed so as to stand up from the peripheral edge of the opening 65.

A stator 50 is assembled on 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 assembling the stator core 52 to the outside 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 may be assembled to the unit base 61 by adhesion, shrink fitting, press fitting, or the like. As a result, the displacement of the stator core 52 in the circumferential direction or the axial direction with respect to the unit base 61 side is suppressed.

Further, the radial inside of the casing 64 is a storage space for accommodating the electric component 62, and the electric component 62 is arranged so as to surround the rotating shaft 11 in the accommodation space. The casing 64 has a role as a storage space forming portion. The electric component 62 is configured to include a semiconductor module 66 constituting 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 constitute the 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 with the rotor 40 interposed therebetween, and the housing 30 and the unit base 61 are coupled to each other on the other side. For example, in an electric vehicle or the like which is an electric vehicle, the rotary electric machine 10 is attached to the vehicle or the like by attaching a motor housing to the side of the vehicle or the like.

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

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

The tubular portion 71 of the casing 64 is a partition portion that partitions between the rotor 40 and the stator 50 arranged radially outside and the electrical component 62 arranged radially inside, and is a cylinder. The rotor 40, the stator 50, and the electrical component 62 are arranged so as to be arranged in and out of the radial direction with the shape portion 71 interposed therebetween.

Further, the electric component 62 is an electric component constituting an inverter circuit, and has a power running function of passing a current through each phase winding of the stator winding 51 in a predetermined order to rotate the rotor 40, and a 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 coil and outputting it to the outside as generated power. 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 that outputs regenerative power to the outside when the rotary electric machine 10 is used as a power source for a vehicle.

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 of the above are arranged side by side in the circumferential direction. The capacitor module 68 includes a plurality of smoothing capacitors 68a connected in parallel to each other. Specifically, the capacitor 68a is a laminated film capacitor in which a plurality of film capacitors are laminated, and has a trapezoidal cross section. The capacitor module 68 is configured by arranging 12 capacitors 68a side by side in an annular shape.

In the manufacturing process of the capacitor 68a, for example, a long film having a predetermined width in which a plurality of films are laminated is used, the film width direction is the trapezoidal height direction, and the upper and lower bases of the trapezoid are alternately alternated. A capacitor element is made by cutting a long film into an isobaric shape so as to be. Then, a capacitor 68a is manufactured by attaching an electrode or the like to the capacitor element.

The semiconductor module 66 has a semiconductor switching element such as a MOSFET or an IGBT, and is formed in a substantially plate shape. In the present embodiment, since the rotary electric machine 10 includes two sets of three-phase windings and an inverter circuit is provided for each of the three-phase windings, a total of 12 semiconductor modules 66 are formed by arranging them in an annular shape. The semiconductor module group 66A is provided in the electric component 62.

The semiconductor module 66 is arranged so as to be sandwiched between the tubular 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 transferred to the end plate 63 via the casing 64 and released from the end plate 63.

The semiconductor module group 66A may have a spacer 69 on the outer peripheral surface side, that is, in the radial direction between the semiconductor module 66 and the tubular portion 71. 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, so that the spacer 69 is an inner peripheral surface. Is a flat surface and the outer peripheral surface is a curved surface. The spacer 69 may be integrally provided so as to be connected in an annular shape on the radial outer side of the semiconductor module group 66A. The spacer 69 is a good thermal conductor, and may be, for example, a metal such as aluminum, a heat radiating gel sheet, or the like. It is also possible to make the cross-sectional shape of the inner peripheral surface of the tubular portion 71 the same dodecagon as the capacitor module 68. In this case, it is preferable that both the inner peripheral surface and the outer peripheral surface of the spacer 69 are flat surfaces.

Further, in the present embodiment, a cooling water passage 74 for flowing cooling water is formed in the tubular portion 71 of the casing 64, and the heat generated in the semiconductor module 66 is directed to the cooling water flowing through the cooling water passage 74. Even released. That is, the casing 64 is provided with 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 electrical component 62 (semiconductor module 66 and condenser module 68). The semiconductor module 66 is arranged along the inner peripheral surface of the tubular portion 71, and the cooling water passage 74 is provided at a position where the semiconductor module 66 overlaps the semiconductor module 66 in the radial direction inside and outside.

Since the stator 50 is arranged on the outside of the tubular portion 71 and the electrical component 62 is arranged on the inside, the heat of the stator 50 is transferred to the tubular portion 71 from the outside, and the heat of the stator 50 is transferred to the tubular portion 71. The heat of the electric component 62 (for example, the heat of the semiconductor module 66) is transferred 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 constituting a part or all of the inverter circuit for operating the rotary electric machine by energizing the stator winding 51 is radially outside the tubular portion 71 of the casing 64. It is arranged in the area surrounded by the stator core 52 arranged in. Desirably, the entire semiconductor module 66 is arranged in the region surrounded by the stator core 52. Further, preferably, the entire semiconductor module 66 is arranged in the region surrounded by the stator core 52.

Further, at least a part of the semiconductor module 66 is arranged in the region surrounded by the cooling water passage 74. Desirably, the entire semiconductor module 66 is located in the region surrounded by the yoke 141.

Further, the electrical component 62 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 facing 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 sandwiched between them. A wiring module 76 is assembled on the second end surface of the capacitor module 68 near the opening 65.

The wiring module 76 has a main body portion 76a made of a synthetic resin material and having a circular plate shape, and a plurality of bus bars 76b and 76c embedded therein. The bus bars 76b and 76c are used to form a semiconductor module 66 and a capacitor. It has an electrical connection with module 68. Specifically, the semiconductor module 66 has a connecting pin 66a extending from its axial end face, and the connecting pin 66a is connected to the bus bar 76b on the radial outer side of the main body portion 76a. Further, the bus bar 76c extends to the side opposite to the capacitor module 68 on the radial outer side of the main body portion 76a, and is connected to the wiring member 79 at the tip end portion thereof (see FIG. 2).

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

Further, since the capacitor module 68 has a hollow cylindrical shape and the rotating shaft 11 is arranged on the inner peripheral portion thereof with a predetermined gap interposed therebetween, the heat of the capacitor module 68 can be released from the hollow portion as well. ing. In this case, the rotation of the rotating shaft 11 causes a flow of air, so that the cooling effect is enhanced.

A disk-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 a microcomputer is mounted on the board. There is. The control board 67 is fixed to the wiring module 76 by a fixture such as a screw. The control board 67 has an insertion hole 67a in which the rotation shaft 11 is inserted in the central portion thereof.

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 thereof. The first surface faces the capacitor module 68. The wiring module 76 is provided with a control board 67 on the second surface thereof. The bus bar 76c of the wiring module 76 extends from one side of both sides 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, it is preferable that a part of the outer edge portion of the control board 67 having a circular shape is 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 on the outside thereof, it occurs in the inverter circuit. Electromagnetic noise is suitably shielded. That is, in the inverter circuit, switching control is performed in each semiconductor module 66 by utilizing PWM control with a predetermined carrier frequency, and it is conceivable that 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 radial outer side of the 62.

Further, at least a part of the semiconductor module 66 is arranged in the region surrounded by the stator core 52 arranged radially outside the tubular portion 71 of the casing 64, whereby the semiconductor module 66 and the stator winding are arranged. Compared to the configuration in which the 51 is arranged without the stator core 52, even if the semiconductor module 66 generates a magnetic flux, the stator winding 51 is less likely to be affected. Further, even if the magnetic flux is generated from the stator winding 51, it is unlikely to affect the semiconductor module 66. It is more effective if the entire semiconductor module 66 is arranged in the region surrounded by the stator core 52 arranged on the radial outer side of 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 the effect that the heat generated from the stator winding 51 and the magnet unit 42 is difficult to reach the semiconductor module 66.

In the tubular portion 71, a through hole 78 is formed in the vicinity of the end plate 63 through which a wiring member 79 (see FIG. 2) for electrically connecting the outer stator 50 and the inner electrical component 62 is inserted. There is. As shown in FIG. 2, the wiring member 79 is connected to the end 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 it is desirable that the joint surface thereof be flattened. The through holes 78 are preferably provided at one place or a plurality of places, and in the present embodiment, the through holes 78 are provided at two places. In a configuration in which 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. It has become.

As described above, as shown in FIG. 4, a rotor 40 and a stator 50 are provided in the housing 30 in this order from the outside in the radial direction, and an inverter unit 60 is provided inside the stator 50 in the radial direction. Here, assuming that 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 of d × 0.705 from the rotation center of the rotor 40. There is. In this case, the region of the rotor 40 and the stator 50 that is radially inward from the inner peripheral surface of the stator 50 that is radially inner (that is, the inner peripheral surface of the stator core 52) is defined as the first region X1 in the radial direction. Assuming that 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 the 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, the first region X1 radially inside from the inner peripheral surface of the magnetic circuit component assembly in the housing 30 is the magnetic circuit component assembly in the radial direction. The volume is larger than that of the second region X2 between the inner peripheral surface of the above 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 rotary electric machine, a stator core made of a laminated steel plate and forming an annular shape is provided with a plurality of slots in the circumferential direction, and a stator winding is wound in the slots. There is. Specifically, the stator core has a plurality of teeth extending in the radial direction from the yoke at predetermined intervals, and slots are formed between the teeth adjacent to each other in the circumferential direction. Then, for example, a plurality of layers of conducting wires are accommodated in the slot in the radial direction, and the stator winding is formed by the conducting wires.

However, in the above-mentioned 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 magnetic saturation in the rotating electric machine. It is possible that the torque density is limited. That is, in the stator core, it is considered that magnetic saturation occurs when the rotational magnetic flux generated by the energization of the stator winding is concentrated on the teeth.

Further, generally, as a configuration of an IPM (Interior Permanent Magnet) rotor in a rotary electric machine, a permanent magnet is arranged on the d-axis in the d-q coordinate system, and a rotor core is arranged on the q-axis. In such a case, the stator winding near the d-axis is excited, so that the 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] showing the magnetomotive force of the stator winding and the torque density [Nm / L]. The broken line shows the characteristics of a general IPM rotor type rotary electric machine. As shown in FIG. 7, in a general rotary electric machine, by increasing the magnetomotive force in the stator, magnetic saturation occurs in two places, the tooth portion between the slots and the q-axis core portion, which causes magnetic saturation. 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 rotary electric machine 10 is provided with the following configuration. That is, as a first device, in order to eliminate the magnetic saturation that occurs in the teeth of the stator core in the stator, a slotless structure is adopted in the stator 50, and in order to eliminate the magnetic saturation that occurs in the q-axis core portion of the IPM rotor. , SPM (Surface Permanent Magnet) rotor is adopted. According to the first device, the above-mentioned two parts where magnetic saturation occurs can be eliminated, but it is considered that the torque in the low current region is reduced (see the alternate long and short dash line in FIG. 7). Therefore, as a second device, in order to recover the torque decrease by increasing the magnetic flux of the SPM rotor, the magnet unit 42 of the rotor 40 adopts a polar anisotropic structure in which the magnetic path is lengthened to increase the magnetic force. ing.

Further, as a third device, the coil side portion 53 of the stator winding 51 adopts a flat conductor structure in which the radial thickness of the stator 50 of the conductor is reduced to recover the torque reduction. 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 in which the magnetic force is increased. However, according to the third device, since the flat conducting wire structure is thin in the radial direction, it is possible to suppress the generation of eddy current in the radial direction 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, a magnet having a high magnetic force is used to expect a significant improvement in torque characteristics, but the magnet has a high magnetic force. Concerns about the generation of large eddy currents that can occur can also be improved.

Further, as a fourth device, a magnet unit having a magnetic flux density distribution close to a sine wave is adopted by utilizing an extremely heterogeneous structure. According to this, the sine wave matching rate can be increased by pulse control or the like described later to increase the torque, and eddy current loss (copper loss due to eddy current: eddy current loss) due to a gentler magnetic flux change than that of a radial magnet. ) Can also be further suppressed.

Hereinafter, the sine wave matching factor will be described. The sine wave matching factor 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 the sine wave having the same period and peak value. The ratio of the amplitude of the primary waveform, which is the fundamental wave of the rotating electric machine, to the amplitude of the actually measured waveform, that is, the amplitude obtained by adding other harmonic components to the fundamental wave, corresponds to the sine wave matching factor. As the sinusoidal matching factor increases, the waveform of the surface magnetic flux density distribution approaches the sinusoidal shape. Then, when a first-order sine wave current is supplied from the inverter to a rotating electric machine equipped with a magnet having an improved sine wave matching rate, the waveform of the surface magnetic flux density distribution of the magnet is close to the sine wave shape. , Can 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 equations.

Further, as a fifth device, the stator winding 51 has a wire conductor structure in which a plurality of wire wires are gathered and bundled. According to this, since the strands are connected in parallel, a large current can flow, and the eddy current generated by the conductors that spread in the circumferential direction of the stator 50 in the flat conductor structure is generated by the cross-sectional area of each strand. Is smaller, so it can be suppressed more effectively than thinning in the radial direction by the third device. Then, by forming a structure in which a plurality of strands are twisted together, it is possible to cancel the eddy current with respect to the magnetic flux generated by the right-handed screw rule with respect to the current energizing direction with respect to the magnetomotive force from the conductor.

In this way, if the fourth and fifth devices are further added, the torque can be increased while using the magnet with a high magnetic force, which is the second device, while suppressing the eddy current loss caused by the high magnetic force. Can be planned.

Hereinafter, the slotless structure of the stator 50, the flat conducting wire structure of the stator winding 51, and the extremely heterogeneous structure of the magnet unit 42 will be individually described. Here, first, the slotless structure of the stator 50 and the flat conducting wire structure of the stator winding 51 will be described. FIG. 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. FIG. 10 is a cross-sectional view showing a cross section of the stator 50 along the line XX of FIG. 11, and FIG. 11 is a cross-sectional view showing a vertical cross section of the stator 50. Further, FIG. 12 is a perspective view of the stator winding 51. In addition, in FIG. 8 and FIG. 9, the magnetization 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 sheets 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 assembled on the outer side in the radial direction. In the stator core 52, the outer peripheral surface on the rotor 40 side serves as a conductor area. The outer peripheral surface of the stator core 52 has a curved surface without unevenness, and a plurality of lead wire groups 81 are arranged at predetermined intervals in the circumferential direction on the outer peripheral surface. 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 of the two lead wire groups 81 adjacent to each other 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 of each of the lead wire groups 81. That is, in the stator 50, the inter-lead wire members provided between the lead wire groups 81 in the circumferential direction are configured as the sealing member 57 which is a non-magnetic material. Speaking in the state before sealing of the sealing member 57, the conducting wire groups 81 are arranged at predetermined intervals in the circumferential direction on the radial outer side of the stator core 52, respectively, with a gap 56 which is a region between the conducting wires. As a result, the stator 50 having a slotless structure is constructed. In other words, each conductor group 81 is composed of two conductors 82 as described later, and only the non-magnetic material occupies between the two conductors 81 adjacent to each other in the circumferential direction of the stator 50. There is. The non-magnetic material includes a non-magnetic gas such as air, a non-magnetic liquid, and the like 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 lead 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 each lead wire group has a predetermined width. It can be said that a part of the magnetic circuit, that is, a magnetic 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 lead wire groups 81 is the configuration in which the above-mentioned 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). It is formed. The thickness T2 is the shortest distance between the outer surface and the inner surface facing each other in the radial direction of the stator winding 51. The width W2 is a fixation that functions as one of the polyphases 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 length in the circumferential direction of the stator winding 51 which is a part of the child winding 51. Specifically, in FIG. 10, when two lead wire groups 81 adjacent to each other in the circumferential direction function as one of the three phases, for example, the U phase, the two lead wire groups 81 are end-to-end in the circumferential direction. Width up to W2. The thickness T2 is smaller than the width W2.

The thickness T2 is preferably smaller than the total width dimension of the two lead wire groups 81 existing in the width W2. If the cross-sectional shape of the stator winding 51 (more specifically, the lead wire 82) is a perfect circle shape, an elliptical shape, or a polygonal shape, among the cross sections of the lead wire 82 along the radial direction of the stator 50, In the cross section, the maximum length of the stator 50 in the radial direction may be W12, and the maximum length of the stator 50 in the circumferential direction 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 together with the stator core 52 by a molding material. The resin can be regarded as a non-magnetic material or an equivalent of the non-magnetic material as Bs = 0.

Looking at the cross section of FIG. 10, the sealing member 57 is provided between the lead wire groups 81, that is, the gap 56 is filled with the synthetic resin material, and the sealing member 57 between the lead wire groups 81. Insulation 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 provided on the radial outer side of the stator core 52 in a range including all of the lead wire groups 81, that is, in a range in which the radial thickness dimension is larger than the radial thickness dimension of each lead 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, a sealing member 57 is provided within a range including at least a part of the end faces of the stator core 52 facing in the axial direction. In this case, the stator winding 51 is resin-sealed almost entirely except for the ends of the phase windings of each phase, that is, the connection terminals with the inverter circuit.

In the configuration in which the sealing member 57 is provided in a range including the end face 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. As a result, the sealing member 57 can be used to maintain the laminated state of each steel plate. In the present embodiment, the inner peripheral surface of the stator core 52 is not resin-sealed, but instead, the entire stator core 52 including the inner peripheral surface of the stator core 52 is resin-sealed. It may be a configuration.

When the rotary electric machine 10 is used as a vehicle power source, the sealing member 57 is made of a 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. Further, considering the coefficient of linear expansion from the viewpoint of suppressing cracking due to the difference in expansion, it is desirable that the material is the same as the outer coating of the lead wire of the stator winding 51. That is, a silicon resin having a coefficient of linear expansion that is generally more than double that of other resins is preferably excluded. For electric products that do not have an engine that utilizes combustion, such as electric vehicles, PPO resin, phenol resin, and FRP resin that have heat resistance of about 180 ° C. are also candidates. This does not apply in the field where the ambient temperature of the rotary electric machine can be regarded as less than 100 ° C.

The torque of the rotary electric machine 10 is proportional to the magnitude of the 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 this case, the maximum amount of magnetic flux in the stator is not limited. Therefore, the configuration is advantageous in increasing the energizing current for 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 a structure (slotless structure) in which the stator 50 has no teeth. Specifically, in the stator of a general rotary electric machine in which a lead wire is accommodated in each slot partitioned by a plurality of teeth, the inductance is, for example, about 1 mH, whereas in the stator 50 of the present embodiment, the inductance is high. It is reduced to about 5 to 60 μH. In the present embodiment, it is possible to reduce the mechanical time constant Tm by reducing the inductance of the stator 50 while using the rotary electric machine 10 having an outer rotor structure. That is, it is possible to reduce the mechanical time constant Tm while increasing the torque. Assuming that the inertia is J, the inductance is L, the torque constant is Kt, and the counter 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 mechanical time constant Tm is reduced by reducing the inductance L.

Each lead wire group 81 on the radial outer side of the stator core 52 is configured by arranging a plurality of lead wires 82 having a flat rectangular cross section side by side in the radial direction of the stator core 52. Each lead wire 82 is arranged in a direction such that "diameter direction dimension <circumferential direction dimension" in the cross section. As a result, the thickness of each lead wire group 81 is reduced in the radial direction. In addition, the thickness in the radial direction is reduced, and the conductor region extends flat to the region where the teeth have been conventionally, forming a flat conductor region structure. As a result, the increase in the amount of heat generated by the conductor, which is a concern because the cross-sectional area becomes smaller due to the thinning, is suppressed by flattening in the circumferential direction to increase the cross-sectional area of the conductor. Even if a plurality of conductors are arranged in the circumferential direction and connected in parallel, the conductor cross-section of the conductor coating is reduced, but the same reasoning effect can be obtained. In the following, each of the conductor group 81 and each of the conductor 82 will also be referred to as a conductive member.

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

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

In other words, it is preferable that the thickness dimension Tc in the radial direction of each lead wire 82 is smaller than the width dimension Wc in the circumferential direction. Furthermore, the radial thickness dimension (2Tc) of the lead wire group 81 composed of two layers of lead wires 82 in the radial direction, that is, the radial thickness dimension (2Tc) of the lead wire group 81 is larger than the circumferential width dimension Wc. It should be small.

The torque of the rotary electric machine 10 is substantially inversely proportional to the radial thickness of the stator core 52 of the lead wire group 81. In this respect, the thickness of the lead wire group 81 is reduced on the radial outer side 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 lowered by reducing the distance from the magnet unit 42 of the rotor 40 to the stator core 52 (that is, the distance of the iron-free portion). 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 lead wire group 81, even if the magnetic flux leaks from the lead wire group 81, it is easily collected by the stator core 52, and the magnetic flux leaks to the outside without being effectively used for improving torque. Can be suppressed. That is, it is possible to suppress a decrease in magnetic force due to magnetic flux leakage, and it is possible to increase the interlinkage magnetic flux of the stator core 52 by the permanent magnet to increase the torque.

The conductor 82 is composed of a coated conductor whose surface of the conductor body 82a is covered with an insulating coating 82b, and is between the conductors 82 which overlap each other in the radial direction and between the conductor 82 and the stator core 52. Insulation is ensured in each. The insulating coating 82b is composed of a coating if the strand 86 described later is a self-bonding coated wire, or an insulating member laminated separately from the coating of the strand 86. It should be noted that each phase winding composed of the lead wire 82 retains the insulating property by 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 a star-shaped connection. In the lead wire group 81, the lead wires 82 adjacent to each other 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 rubbing of the lead wires 82 against each other are suppressed.

In this embodiment, the conductor 82a is configured as an aggregate of a plurality of wires 86. Specifically, as shown in FIG. 13, the conductor 82a is formed in a twisted thread shape by twisting a plurality of strands 86. Further, as shown in FIG. 14, the wire 86 is configured as a composite in which thin fibrous conductive materials 87 are bundled. For example, the wire 86 is a composite of CNT (carbon nanotube) fibers, and as the CNT fiber, a fiber containing boron-containing fine fibers in which at least a part of carbon is replaced with boron is used. As the carbon-based fine fiber, a vapor phase growth method carbon fiber (VGCF) or the like can be used in addition to the CNT fiber, but it is preferable to use the CNT fiber. The surface of the wire 86 is covered with a polymer insulating layer such as enamel. Further, it is preferable that the surface of the wire 86 is covered with a so-called enamel film composed of a polyimide film or an amidimide film.

The lead wire 82 constitutes an n-phase winding in the stator winding 51. Then, the respective strands 86 of the conductor 82 (that is, the conductor 82a) are adjacent to each other in contact with each other. In the lead wire 82, the winding conductor has a portion formed by twisting a plurality of strands 86 at one or more places in the phase, and the resistance value between the twisted strands 86 is the strand 86 itself. It is an aggregate of strands larger than the resistance value of. In other words, if each of the two adjacent strands 86 has a first electrical resistivity in its adjacent direction and each of the strands 86 has a second electrical resistivity in its length direction, then the first electrical resistance The rate is larger than the second electrical resistivity. The lead wire 82 may be formed of a plurality of strands 86, and may be an aggregate of strands covering the plurality of strands 86 by an insulating member having an extremely high first electrical resistivity. Further, the conductor 82a of the conducting wire 82 is composed of a plurality of strands 86 twisted together.

Since the conductor 82a is configured by twisting a plurality of strands 86, it is possible to suppress the generation of eddy currents in each of the strands 86 and reduce the eddy currents in the conductor 82a. Further, since each wire 86 is twisted, a portion where the magnetic field application directions are opposite to each other is generated in one wire 86, and the counter electromotive voltage is canceled out. Therefore, the eddy current can also be reduced. In particular, by forming the wire 86 with the fibrous conductive material 87, it becomes possible to make the wire thinner and to significantly increase the number of twists, and it is possible to more preferably reduce the eddy current.

The method of insulating the wires 86 from each other here is not limited to the above-mentioned polymer insulating film, and may be a method of making it difficult for current to flow between the twisted wires 86 by utilizing contact resistance. That is, if the resistance value between the twisted strands 86 is larger than the resistance value of the strands 86 itself, the above effect can be obtained by the potential difference generated due to the difference in the resistance values. .. For example, by using the manufacturing equipment for creating the wire 86 and the manufacturing equipment for making the stator 50 (armature) of the rotary electric machine 10 as separate non-continuous equipment, the wires are used based on the movement time and work interval. 86 is suitable because it can be oxidized and the contact resistance can be increased.

As described above, the lead wires 82 have a flat rectangular cross section and are arranged side by side in the radial direction. For example, a plurality of lead wires 82 covered with a self-bonding coated wire having a fusion layer and an insulating layer. The wire 86 is assembled in a twisted state, and the fused layers are fused to maintain the shape. It should be noted that the strands having no fusion layer or the strands of the self-bonding coated wire may be twisted and molded into a desired shape with a synthetic resin or the like. When the thickness of the insulating coating 82b in the lead wire 82 is set to, for example, 80 μm to 100 μm and is thicker than the film thickness (5 to 40 μm) of the generally used lead wire, insulation is provided between the lead wire 82 and the stator core 52. Insulation between the two can be ensured without the intervention of paper or the like.

Further, it is desirable that the insulating coating 82b has 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 set to, for example, about 5 μm, the thickness of the insulating coating 82b of the lead wire 82 is set to about 80 μm to 100 μm so that insulation between the phases can be preferably performed. Is desirable.

Further, the lead wire 82 may have a configuration in which a plurality of strands 86 are bundled without being twisted. That is, the lead wire 82 has a configuration in which a plurality of strands 86 are twisted in the entire length, a configuration in which a plurality of strands 86 are twisted in a part of the total length, and a plurality of strands 86 are twisted in the total length. It may be any of the configurations that are bundled together. In summary, each lead wire 82 constituting the lead wire portion is a set of strands in which a plurality of strands 86 are bundled and the resistance value between the bundled strands is larger than the resistance value of the strand 86 itself. It has become.

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

In the present embodiment, the stator winding 51 is wound in an annular shape by distributed winding. In this case, in the coil side portion 53, 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, each linear portion 83 for each phase is arranged. , They are connected to each other by a turn portion 84 formed in a substantially V shape. The directions of the currents of the linear portions 83 that are paired corresponding to the one-pole pair are opposite to each other. Further, the combination of the pair of linear portions 83 connected by the turn portion 84 is different between the one coil end 54 and the other coil end 55, and the connections at the coil ends 54 and 55 are in the circumferential direction. By repeating the process, the stator winding 51 is formed in a substantially cylindrical shape.

More specifically, the stator winding 51 constitutes a winding for each phase by using two pairs of lead wires 82 for each phase, and one of the stator windings 51 is a three-phase winding (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, if the number of phases of the stator winding 51 is S (6 in the case of the embodiment) and the number of wires 82 per phase is m, then 2 × S × m = 2 Sm wires for each pole pair. 82 will be formed. In the present embodiment, the number of phases S is 6, the number of m is 4, and since it is an 8-pole pair (16-pole) rotary electric machine, the lead wire 82 of 6 × 4 × 8 = 192 is the circumference of the stator core 52. 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 in two layers adjacent in the radial direction, and in the coil ends 54 and 55, the linear portions overlapping in the radial direction are respectively arranged. From 83, the turn portion 84 extends in the circumferential direction in directions opposite to each other in the circumferential direction. That is, in each of the conducting wires 82 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 lead 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 stacked on a plurality of layers (for example, two layers) adjacent to each other in the radial direction. 15 (a) and 15 (b) are views showing the form of each lead wire 82 in the nth layer, and FIG. 15 (a) shows the lead wire 82 seen from the side of the stator winding 51. The shape is shown, and FIG. 15B shows the shape of the lead wire 82 seen from one side in the axial direction of the stator winding 51. In addition, in FIG. 15A and FIG. 15B, the positions where the lead wire group 81 is arranged are shown as D1, D2, D3, ..., Respectively. Further, for convenience of explanation, only three lead wires 82 are shown, which are referred to as the first lead wire 82_A, the second lead wire 82_B, and the third lead wire 82_C.

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

Specifically, the turn portion 84 of each of the conducting wires 82_A to 82_C is from one inclined portion 84a which is a portion extending in the circumferential direction on the same circle (first circle) and the same circle from the inclined portion 84a. From the top 84b, which shifts inward in the radial direction (upper side in FIG. 15B) and reaches another circle (second circle), the inclined portion 84c extending in the circumferential direction on the second circle, and the first circle. It has a return portion 84d that returns to the second circle. The top portion 84b, the inclined portion 84c, and the return portion 84d correspond to the interference avoidance portion. The inclined portion 84c may be configured to shift outward in the radial direction with respect to the inclined portion 84a.

That is, the turn portions 84 of the lead wires 82_A to 82_C have an inclined portion 84a on one side and an inclined portion 84c on the other side on both sides of the top portion 84b which is the central position in the circumferential direction. The radial positions of the inclined portions 84a and 84c (the position in the front-rear direction of the paper surface in FIG. 15A and the position in the vertical direction in FIG. 15B) are different from each other. For example, the turn portion 84 of the first lead wire 82_A extends along the circumferential direction starting from the D1 position of the n-layer, bends in the radial direction (for example, inward in the radial direction) at the top portion 84b which is the central position in the circumferential direction, and then. By bending again in the circumferential direction, it extends along the circumferential direction again, and further bends in the radial direction (for example, outside in the radial direction) at the return portion 84d to reach the D7 position of the n layer, which is the end point position. There is.

According to the above configuration, in the lead wires 82_A to 82_C, one of the inclined portions 84a is arranged vertically in the order of the first lead wire 82_A → the second lead wire 82_B → the third lead wire 82_C from the top, and the respective lead wires 82_A to the top 84b. The top and bottom of 82_C are interchanged, and the other inclined portions 84c are arranged vertically in the order of the third lead wire 82_C → the second lead wire 82_B → the first lead wire 82_A from the top. Therefore, the lead wires 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 lead wires 82 are stacked in the radial direction to form a lead wire group 81, the turn portion 84 connected to the linear portion 83 on the inner side in the radial direction and the outer side in the radial direction among the straight line portions 83 of the plurality of layers It is preferable that the turn portion 84 connected to the straight portion 83 is arranged radially away from each of the straight portions 83. Further, when the lead wires 82 of a plurality of layers are bent to the same side in the radial direction near the end of the turn portion 84, that is, the boundary portion with the straight portion 83, the insulating properties are provided by the interference between the lead wires 82 of the adjacent layers. It is good to prevent the damage from being damaged.

For example, in D7 to D9 of FIGS. 15A and 15B, each of the conducting wires 82 overlapping in the radial direction is bent in the radial direction at the return portion 84d of the turn portion 84. In this case, as shown in FIG. 16, it is preferable that the radius of curvature of the bent portion is different between the nth layer conducting wire 82 and the n + 1th layer guiding wire 82. Specifically, the radius of curvature R1 of the radial inner (nth layer) lead wire 82 is made smaller than the radius of curvature R2 of the radial outer (n + 1th layer) lead wire 82.

Further, it is preferable that the radial shift amount differs between the n-th layer lead wire 82 and the n + 1-th layer lead wire 82. Specifically, the shift amount S1 of the conductive wire 82 on the inner side in the radial direction (nth layer) is made larger than the shift amount S2 of the lead wire 82 on the outer side in the radial direction (n + 1th layer).

With the above configuration, mutual interference between the conducting wires 82 can be suitably avoided even when the conducting wires 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 the present embodiment, it is assumed that the magnet unit 42 is made of a permanent magnet, has a residual magnetic flux density Br = 1.0 [T], and has an intrinsic coercive force Hcj = 400 [kA / m] or more. In short, the permanent magnet used in this embodiment is a sintered magnet obtained by sintering and solidifying a granular magnetic material, and the intrinsic coercive force Hcj on the JH curve is 400 [kA / m] or more. And the residual magnetic flux density Br is 1.0 [T] or more. When 5000-10000 [AT] is applied by interphase excitation, it passes through the magnet in the magnetic length of one pole pair, that is, the north pole and the south pole, in other words, the path through which the magnetic flux flows between the north pole and the south pole. 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, the magnet unit 42 has a saturation magnetic flux density Js of 1.2 [T] or more, a crystal particle size of 10 [μm] or less, and Js × α of 1 when the orientation rate is α. It is 0.0 [T] or more.

The magnet unit 42 will be supplemented below. The magnet unit 42 (magnet) is characterized in that 2.15 [T] ≧ Js ≧ 1.2 [T]. In other words, examples of the magnet used in the magnet unit 42 include NdFe11TiN, Nd2Fe14B, Sm2Fe17N3, and FeNi magnets having L10 type crystals. In addition, SmCo5, which is usually called Samarium-cobalt, and configurations such as FePt, Dy2Fe14B, and CoPt cannot be used. Note that the same type of compounds, such as Dy2Fe14B and Nd2Fe14B, generally utilize the heavy rare earth dysprosium to slightly lose the high Js properties of neodymium, but the high coercive force of Dy. 2.15 [T] ≧ Js ≧ 1.2 [T] may be satisfied even with a magnet provided with the above, and this case can also be adopted. In such a case, it is called ([Nd1-xDyx] 2Fe14B), for example. Furthermore, it can be achieved with two or more types of magnets having different compositions, for example, magnets made of two or more types of materials such as FeNi plus Sm2Fe17N3. For example, Js = 1.6 [T] and Js. This can be achieved by mixing a small amount of Js <1 [T], for example, Dy2Fe14B, with a magnet of Nd2Fe14B that has a margin to increase the coercive force.

In addition, for rotary electric machines that operate at temperatures outside the range of human activity, for example, 60 ° C or higher, which exceeds the temperature of the desert, for example, in vehicle motor applications where the temperature inside the vehicle is close to 80 ° C in summer. In particular, it is desirable to contain the components of FeNi and Sm2Fe17N3, which have a small temperature dependence coefficient. This is a temperature dependence coefficient in motor operation from a temperature state close to -40 ° C in Scandinavia, which is within the range of human activity, to 60 ° C or higher, which exceeds the desert temperature mentioned above, or to a heat resistant temperature of 180 to 240 ° C for coil enamel coatings. This is because the motor characteristics differ greatly depending on the motor, and it becomes difficult to perform optimum control with the same motor driver. If FeNi having the L10 type crystal, Sm2Fe17N3, or the like is used, the load on the motor driver can be suitably reduced due to its characteristic of having a temperature dependence coefficient of less than half that of Nd2Fe14B.

In addition, the magnet unit 42 is characterized in that the size of the particle size in the fine powder state before orientation is 10 μm or less and the particle size in the single magnetic domain or more by using the magnet combination. In magnets, the coercive force is increased by refining the powder particles to the order of several hundred nm. Therefore, in recent years, powder as fine as possible has been used. However, if the size is too fine, the BH product of the magnet will drop due to oxidation or the like, so a single magnetic domain particle size or larger is preferable. It is known that the coercive force increases due to miniaturization if the particle size is up to the single magnetic domain particle size. The size of the particle size described here is the size of the particle size in the fine powder state at the time of the alignment step in the magnet manufacturing process.

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, in which magnetic powder is baked and hardened at a high temperature. In this sintering, when 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 the orientation ratio is α, Js × α is It is performed so as to satisfy the condition of 1.0 T (tesla) or more. Further, each of the first magnet 91 and the second magnet 92 is sintered so as to satisfy the following conditions. Then, since the orientation is performed in the orientation step in the manufacturing process, the orientation ratio is different from the definition of the magnetic force direction by the magnetizing step of the isotropic magnet. 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. The orientation rate α referred to here refers to each of the first magnet 91 and the second magnet 92, for example, having six easy-to-magnetize axes, five of which face the direction A10 in the same direction, and the remaining one. If one is facing the direction B10 that is tilted 90 degrees with respect to the direction A10, α = 5/6, and if the other one is facing the direction B10 that is tilted 45 degrees with respect to the direction A10, the rest. Since the component facing one direction A10 is cos45 ° = 0.707, α = (5 + 0.707) / 6. In this embodiment, the first magnet 91 and the second magnet 92 are formed by sintering, but if the above conditions are satisfied, the first magnet 91 and the second magnet 92 may be molded by another method. .. For example, a method of forming an MQ3 magnet or the like can be adopted.

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

The easily magnetized axis refers to a crystal orientation that is easily magnetized in a magnet. The direction of the easy-to-magnetize axis in the magnet is a direction in which the orientation ratio indicating the degree to which the directions of the easy-to-magnetize axes are aligned is 50% or more, or a direction in which the orientation of the magnet is average.

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, which are polar anisotropic magnets and have different polarities. The first magnet 91 and the second magnet 92 are arranged alternately in the circumferential direction. The first magnet 91 is a magnet that forms an N pole in a portion close to the stator winding 51, and the second magnet 92 is a magnet that forms an S pole in a portion close to the stator winding 51. The first magnet 91 and the second magnet 92 are permanent magnets made of rare earth magnets such as neodymium magnets.

In each of the magnets 91 and 92, as shown in FIG. 9, in the known dq coordinate system, the d-axis (direct-axis) which is the center of the magnetic pole and the magnetic pole boundary between the N pole and the S pole (in other words, the magnetic flux density). The magnetization direction extends in an arc shape with the q axis (quadrature-axis) (where is 0 tesla). In each of the magnets 91 and 92, the magnetization direction is the radial direction of the annular magnet unit 42 on the d-axis side, and the magnetization direction of the annular magnet unit 42 is the circumferential direction on the q-axis side. Hereinafter, it will be described in more detail. 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, as shown in FIG. 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 so that the direction of the easy-to-magnetize axis 300 of the first portion 250 is more parallel to the d-axis than the direction of the easy-to-magnetize axis 310 of the second portion 260. In other words, the magnet unit 42 is configured so that the angle θ11 formed by the easily magnetized axis 300 of the first portion 250 with the d-axis is smaller than the angle θ12 formed by the easily magnetized axis 310 of the second portion 260 with the q-axis. There is.

More specifically, the angle θ11 is an angle formed by the d-axis and the easily magnetized 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 easily magnetized axis 310 when the direction from the stator 50 (armature) to the magnet unit 42 is positive on the q-axis. Both the angle θ11 and the angle θ12 are 90 ° or less in this embodiment. Each of the easily magnetized axes 300 and 310 referred to here is defined by the following. Assuming that one easy-to-magnetize axis points to the direction A11 and the other easy-to-magnetize axis points to the direction B11 in each of the magnets 91 and 92, the cosine of the angle θ formed by the direction A11 and the direction B11. The absolute value (| cosθ |) is defined as the easy magnetization axis 300 or the easy magnetization axis 310.

That is, each of the magnets 91 and 92 has a different easy axis orientation between the d-axis side (the part near the d-axis) and the q-axis side (the part near the q-axis), and magnetizes on the d-axis side. The direction of the easy axis is close to the direction parallel to the d-axis, and the direction of the easy magnetization axis is close to the direction orthogonal to the q-axis on the q-axis side. Then, an arcuate magnet magnetic path is formed according to the direction of the easily magnetized axis. In each of the magnets 91 and 92, the easy magnetization axis may be oriented parallel to the d-axis on the d-axis side, and the easy-magnetization axis may be oriented orthogonal to the q-axis on the q-axis side.

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

In the magnet unit 42, magnetic flux flows in an arc shape between adjacent N and S poles due to the magnets 91 and 92, so that the magnet path is longer than, for example, a radial anisotropic magnet. Therefore, as shown in FIG. 17, the magnetic flux density distribution is close to that of 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 pole, and the torque of the rotary electric machine 10 can be increased. Further, 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 magnet. In FIGS. 17 and 18, the horizontal axis represents the electric angle and the vertical axis represents the magnetic flux density. Further, in FIGS. 17 and 18, 90 ° on the horizontal axis indicates the d-axis (that is, the center of the magnetic pole), and 0 ° and 180 ° on the horizontal axis indicate the q-axis.

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

The sinusoidal matching factor of the magnetic flux density distribution may be, for example, a value of 40% or more. By doing so, it is possible to surely improve the amount of magnetic flux in the central portion of the waveform as compared with the case of using a radial alignment magnet or a parallel alignment magnet having a sinusoidal matching factor of about 30%. Further, if the sine wave matching factor is 60% or more, the amount of magnetic flux in the central portion of the waveform can be surely improved as compared with the magnetic flux concentrated arrangement 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. Further, the change in magnetic flux on the stator winding 51 side is also steep. On the other hand, in the present embodiment, the magnetic flux density distribution is a magnetic flux waveform close to a sine wave. Therefore, the change in the magnetic flux density near the q-axis is smaller than the change in the magnetic flux density of the radial anisotropic magnet. As a result, the generation of eddy current can be suppressed.

In the magnet unit 42, a magnetic flux is generated in the vicinity of the d-axis (that is, the center of the magnetic pole) of each of the magnets 91 and 92 in a direction orthogonal to the magnetic flux action surface 280 on the stator 50 side, and the magnetic flux acts on the magnetic flux action on the stator 50 side. The farther away from the surface 280, the more arcuate the shape is from the d-axis. Further, the magnetic flux orthogonal to the magnetic flux acting surface becomes stronger. In this respect, in the rotary electric machine 10 of the present embodiment, since each lead wire group 81 is thinned in the radial direction as described above, the radial center position of the lead 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 radial inside 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 of the magnets 91 and 92 is attracted to the stator core 52 and orbits while using the stator core 52 as a part of the magnetic path. In this case, the direction and path of the magnetic flux of the magnet can be optimized.

The procedure for assembling 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 below as a method for manufacturing the rotary electric machine 10. As shown in FIG. 6, the inverter unit 60 has a unit base 61 and an electric component 62, and each work process including an assembly process of 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 referred to as the first unit, and the assembly including the bearing unit 20, the housing 30 and the rotor 40 is referred to as the second unit.

This manufacturing process is
-The first step of mounting the electrical component 62 inside the unit base 61 in the radial direction,
-The second step of mounting the unit base 61 inside the stator 50 in the radial direction to manufacture the first unit, and
A third step of inserting the fixing portion 44 of the rotor 40 into the bearing unit 20 assembled to the housing 30 to manufacture the second unit, and
・ The fourth step of mounting the first unit inside the second unit in the radial direction, and
Fifth step of fastening and fixing the housing 30 and the unit base 61,
have. The execution order of each of these steps is as follows: 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 high-mix production.

In the first step, a good thermal conductor having good thermal conductivity is attached to at least one of the radial inside of the unit base 61 and the radial outside of the electric component 62 by coating or adhesion, and in that state, The electrical component 62 may be attached to the unit base 61. This makes it possible to effectively transmit the heat generated by the semiconductor module 66 to the unit base 61.

In the third step, the rotor 40 may be inserted while maintaining the coaxiality between the housing 30 and the rotor 40. Specifically, for example, the position of the outer peripheral surface of the rotor 40 (outer peripheral surface of the magnet holder 41) or the inner peripheral surface of the rotor 40 (inner peripheral surface of the magnet unit 42) is determined with reference to the inner peripheral surface of the housing 30. Using a magnet, the housing 30 and the rotor 40 are assembled while sliding either the housing 30 or the rotor 40 along the magnet. As a result, heavy parts can be assembled without applying an eccentric load to the bearing unit 20, and the reliability of the bearing unit 20 is improved.

In the fourth step, it is preferable to assemble both units while maintaining the coaxiality between the first unit and the second unit. Specifically, for example, a jig for determining 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 the first unit and the second unit are formed along the jig. Assemble each of these units while sliding one of them. As a result, it is possible to assemble while preventing mutual interference between the rotor 40 and the stator 50, which is caused by the assembly such as damage to the stator winding 51 and chipping of permanent magnets. It is possible to eradicate defective products.

The order of each of the above steps may be 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 in 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 a control process by the control device 110.

In FIG. 19, two sets of three-phase windings 51a and 51b are shown as stator windings 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, which correspond to power converters, are provided for each of the three-phase windings 51a and 51b, respectively. The inverters 101 and 102 are composed of a full bridge circuit having the same number of upper and lower arms as the number of phases of the phase windings, and the stator windings 51 can be turned on and off by turning on / off a switch (semiconductor switching element) provided on 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 the inverters 101 and 102. The DC power supply 103 is composed of, for example, an assembled battery in which a plurality of single batteries are connected in series. The switches of the inverters 101 and 102 correspond 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. 1 and the like.

The control device 110 includes a microcomputer composed of a CPU and various memories, and performs energization control by turning on / off each switch in the inverters 101 and 102 based on various detection information in the rotary 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, the rotation angle (electric angle information) of the rotor 40 detected by an angle detector such as a resolver, the power supply voltage (inverter input voltage) detected by the voltage sensor, and the current sensor. Includes the energizing current of each phase detected by. The control device 110 generates and outputs an operation signal for operating each of the switches of the inverters 101 and 102. The power generation requirement is, for example, a regenerative drive requirement when the rotary electric machine 10 is used as a power source for a vehicle.

The first inverter 101 includes a series connection body of the upper arm switch Sp and the lower arm switch Sn in 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 the intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase, respectively. Each of these phase windings is star-shaped (Y-connected), and the other end of each phase winding is connected to each other at a neutral point.

The second inverter 102 has the same configuration as the first inverter 101, and includes a series connection body of the upper arm switch Sp and the lower arm switch Sn in 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 the intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase, respectively. Each of these phase windings is star-shaped (Y-connected), and the other end of each phase winding is connected to each other at a neutral point.

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

In FIG. 20, the current command value setting unit 111 uses a torque −dq map and is based on a power running torque command value or a power generation torque command value for the rotary electric machine 10 and an electric angular velocity ω obtained by time-differentiating the electric angle θ. , The d-axis current command value and the 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 power source for a vehicle.

The dq conversion unit 112 sets the current detection values (three phase currents) by the current sensors provided for each phase to the orthogonal 2 with the direction of an axis of a magnetic field, or field direction as the d-axis. It is converted into a d-axis current and a q-axis current, which are components of the dimensional rotation 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 the q-axis command voltage as an operation amount for feedback-controlling the q-axis current to the 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 with respect to 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. Each of the above units 111 to 115 is a feedback control unit that performs feedback control of the fundamental wave current according to the dq conversion theory, and the U-phase, V-phase, and W-phase command voltages are feedback control values.

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

Further, the X, Y, and Z phases also have the same configuration, and the dq conversion unit 122 sets 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 an orthogonal two-dimensional rotating coordinate system having 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 an operation signal of the second inverter 102 based on the three-phase command voltage. Specifically, the operation signal generation unit 126 switches the upper and lower arms in each phase by PWM control based on the magnitude comparison between the signal obtained by standardizing the command voltage of the three phases with the power supply voltage and the carrier signal such as the triangular wave signal. Generates an operation signal (duty signal).

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

Subsequently, the torque feedback control process will be described. This process is mainly used for the purpose of increasing the output of the rotary electric machine 10 and reducing the loss under operating conditions in which the output voltage of each of the inverters 101 and 102 becomes large, such as in a high rotation region and a 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 a torque feedback control process corresponding to the U, V, and W phases and a torque feedback control process corresponding to the X, Y, and Z phases. In FIG. 21, the same configuration as that in FIG. 20 is designated by the same reference numerals and the description thereof will be omitted. Here, first, the control processing on the U, V, and W phases will be described.

The voltage amplitude calculation unit 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 electric angular velocity ω obtained by time-differentiating the electric angle θ. Calculate the voltage amplitude command.

The torque estimation unit 128a calculates the 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 associated with the d-axis current, the q-axis current, and the voltage amplitude command.

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 torque estimation value to the power running torque command value or the generated torque command value. In the torque feedback control unit 129a, the voltage phase command is calculated by using the PI feedback method based on the deviation of the torque estimated value with respect to the power running torque command value or the generated torque command value.

The operation signal generation unit 130a generates an operation signal of the first inverter 101 based on the voltage amplitude command, the voltage phase command, and the electric 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 electric angle θ, and the calculated three-phase command voltage is standardized by the power supply voltage. And, by PWM control based on the magnitude comparison with the carrier signal such as a triangular wave signal, the switch operation signal of the upper and lower arms in each phase is generated.

Incidentally, the operation signal generation unit 130a is based on the pulse pattern information, the voltage amplitude command, the voltage phase command, and the electric angle θ, which are map information associated with the voltage amplitude command, the voltage phase command, the electric angle θ, and the switch operation signal. The switch operation signal may be generated.

Further, the X, Y, Z phase side also has the same configuration, and the torque estimation unit 128b has the X, Y, X, Y, based on the d-axis current and the q-axis current converted by the dq conversion unit 122. The torque estimate 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 torque estimation value to the power running torque command value or the generated torque command value. The torque feedback control unit 129b calculates a voltage phase command using the PI feedback method based on the deviation of the torque estimated value with respect to the force running torque command value or the generated torque command value.

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

Incidentally, the operation signal generation unit 130b is based on the pulse pattern information, the voltage amplitude command, the voltage phase command, and the electric angle θ, which are map information associated with the voltage amplitude command, the voltage phase command, the electric angle θ, and the switch operation signal. The switch operation signal may be generated.

By the way, in the rotary electric machine 10, there is a concern that electrolytic corrosion of bearings 21 and 22 may occur due to the generation of axial current. For example, when the energization of the stator winding 51 is switched by switching, magnetic flux distortion occurs due to a slight deviation in switching timing (switching imbalance), which causes bearings 21 and 22 to support the rotating shaft 11. There is a concern that electrolytic corrosion will occur in the bearing. The distortion of the magnetic flux occurs 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 electrolytic corrosion proceeds.

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

First, as a first measure against electrolytic corrosion, in the stator 50, the space between each lead group 81 in the circumferential direction is made toothless, and the seal between each lead group 81 is made of a non-magnetic material instead of the tooth (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 of the stator 50, even if the switching timing shift occurs when the stator winding 51 is energized, the occurrence of magnetic flux distortion due to the shift timing shift can be suppressed, and eventually the bearings 21 and 22. It is possible to suppress the electrolytic corrosion of. It is preferable that the d-axis inductance is equal to or less than the q-axis inductance.

Further, the magnets 91 and 92 are oriented so that the direction of the easy-magnetizing axis is parallel to the d-axis on the d-axis side as compared with the q-axis side (see FIG. 9). As a result, the magnetic flux of the magnet on the d-axis is strengthened, and the change in surface magnetic flux (increase / decrease in magnetic flux) from the q-axis to the d-axis at each magnetic pole becomes gentle. Therefore, the sudden voltage change caused by the switching imbalance is suppressed, and the configuration is such that it can contribute to the suppression of electrolytic corrosion.

As a second countermeasure against electrolytic corrosion, in the rotary electric machine 10, the bearings 21 and 22 are arranged unevenly on either side in the axial direction with respect to the center in the axial direction of the rotor 40 (see FIG. 2). As a result, the influence of electrolytic corrosion can be reduced as compared with a configuration in which a plurality of bearings are provided on both sides of the rotor in the axial direction. That is, in a configuration in which the rotor is supported by a plurality of bearings, 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 in between) is generated as a high frequency magnetic flux is generated. It is formed, and there is a concern about electrolytic corrosion of the bearing due to the axial current. On the other hand, in the configuration in which the rotor 40 is cantilevered by a plurality of bearings 21 and 22, the closed circuit is not formed and the electrolytic corrosion of the bearings is suppressed.

Further, the rotary electric machine 10 is involved in the configuration for one-sided arrangement of the bearings 21 and 22, and has the following configuration. In the magnet holder 41, a contact avoiding portion that extends in the axial direction and avoids contact with the stator 50 is provided at an 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 shaft current is formed via the magnet holder 41, the closed circuit length can be lengthened 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 with the rotor 40 interposed therebetween, and the housing 30 and the unit base 61 (stator holder) are coupled to each other on the other side. (See FIG. 2). According to this configuration, it is possible to preferably realize a configuration in which the bearings 21 and 22 are unevenly arranged on one side of the rotating shaft 11 in the axial direction. Further, in this configuration, since the unit base 61 is connected to the rotating shaft 11 via the housing 30, the unit base 61 can be arranged at a position electrically separated from the rotating shaft 11. If an insulating member such as resin is interposed between the unit base 61 and the housing 30, the unit base 61 and the rotating shaft 11 are electrically separated from each other. As a result, electrolytic corrosion of the bearings 21 and 22 can be appropriately suppressed.

In the rotary electric machine 10 of the present embodiment, the shaft voltage acting on the bearings 21 and 22 is reduced by arranging the bearings 21 and 22 on one side and the like. Further, the potential difference between the rotor 40 and the stator 50 is reduced. Therefore, it is possible to reduce the potential difference acting on the bearings 21 and 22 without using conductive grease in the bearings 21 and 22. Since the 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, the inconvenience of noise in the bearings 21 and 22 can be suppressed. For example, when it is applied to an electric vehicle such as an electric vehicle, it is considered that a countermeasure against the noise of the rotary electric machine 10 is required, and it is possible to preferably implement the countermeasure against the noise.

In the third electrolytic corrosion countermeasure, the stator winding 51 is molded together with the stator core 52 with a molding material to suppress the displacement of the stator winding 51 in the stator 50 (see FIG. 11). ). In particular, since the rotary electric machine 10 of the present embodiment does not have a wire-to-lead member (teeth) between the wire groups 81 in the circumferential direction of the stator winding 51, there is a concern that the stator winding 51 may be displaced. Although it is conceivable, by molding the stator winding 51 together with the stator core 52, deviation of the lead wire position of the stator winding 51 is suppressed. Therefore, it is possible to suppress the distortion of the magnetic flux due to the misalignment 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 where it is made of, for example, aluminum. As a result, suitable measures against electrolytic corrosion are possible.

In addition, as a countermeasure against electrolytic corrosion of the bearings 21 and 22, it is also possible to use a configuration 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 on the outside of the outer ring 25.

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

(Second Embodiment)
In the present 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 by using a magnet array called a Halbach array. That is, the magnet unit 42 has a first magnet 131 whose magnetization direction (direction of the magnetization vector) is the radial direction, and a second magnet 132 whose circumferential direction (direction of the magnetization vector) is the circumferential direction. The first magnets 131 are arranged at predetermined intervals in the circumferential direction, and the second magnet 132 is arranged at a position between the adjacent first magnets 131 in the circumferential direction. The first magnet 131 and the second magnet 132 are permanent magnets made of rare earth magnets such as neodymium magnets.

The first magnet 131 is arranged so as to be spaced apart from each other in the circumferential direction so that the poles on the side facing the stator 50 (inside in the radial direction) are alternately N poles and S poles. Further, the second magnet 132 is arranged next to each first magnet 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 is preferably 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 magnetization axis with respect to the d-axis and the q-axis in the dq coordinate system as in the first embodiment.

Further, a magnetic material 133 made of a soft magnetic material is arranged on the radial side of the first magnet 131, that is, on the side of the cylindrical portion 43 of the magnet holder 41. For example, the magnetic material 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 (particularly, the circumferential length of the outer peripheral portion of the first magnet 131). Further, the radial thickness of the integrated object in the state where the first magnet 131 and the magnetic body 133 are integrated is the same as the radial thickness of the second magnet 132. In other words, the thickness of the first magnet 131 in the radial direction is thinner than that of the second magnet 132 by the amount of the magnetic body 133. The magnets 131 and 132 and the magnetic material 133 are fixed to each other by, for example, an adhesive. In the magnet unit 42, the radial outside of the first magnet 131 is on the opposite side of the stator 50, and the magnetic body 133 is on the opposite side of the stator 50 from both sides of the first magnet 131 in the radial direction (opposite). 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 protruding outward in the radial direction, that is, toward the cylindrical portion 43 of the magnet holder 41. Further, a key groove 135 is formed on the inner peripheral surface of the cylindrical portion 43 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 key 134 are formed corresponding to the key 134 formed on each magnetic material 133. By engaging the key 134 and the key groove 135, the displacement of the first magnet 131 and the second magnet 132 and the magnet holder 41 in the circumferential direction (rotation direction) is suppressed. It may be arbitrary whether the key 134 and the key groove 135 (convex portion and concave portion) are provided in the cylindrical portion 43 or the magnetic body 133 of the magnet holder 41, and contrary to the above, on the outer peripheral portion of the magnetic body 133. In addition to providing the key groove 135, it is also possible to provide 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 magnet 131 and the second magnet 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 radial outer side of the first magnet 131, that is, on the anti-fixer side, it is possible to suppress partial magnetic saturation on the radial outer side of the first magnet 131, which is caused by magnetic saturation. The demagnetization of the first magnet 131 that occurs can be suppressed. As a result, it is possible to increase the magnetic force of the magnet unit 42. The magnet unit 42 of the present embodiment has, so to speak, a configuration in which a portion of the first magnet 131 in which demagnetization is likely to occur is replaced with a magnetic body 133.

24 (a) and 24 (b) are views specifically showing the flow of magnetic flux in the magnet unit 42, and FIG. 24 (a) shows a conventional configuration in which the magnet unit 42 does not have a magnetic body 133. 24 (b) shows the case where the configuration of the present embodiment having the magnetic material 133 in the magnet unit 42 is used. In FIGS. 24 (a) and 24 (b), the cylindrical portion 43 of the magnet holder 41 and the magnet unit 42 are shown in a straight line, with the lower side of the drawing being the stator side and the upper side being the anti-stator side. 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. Further, 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, the cylindrical portion 43 receives a magnetic flux F1 that enters the contact surface with the first magnet 131 through the outer path of the second magnet 132 and a magnetic flux F2 that is substantially parallel to the cylindrical portion 43 and enters the contact surface of the second magnet 132. A combined magnetic flux with the attractive magnetic flux is generated. Therefore, there is a concern that magnetic saturation may partially occur in the vicinity of the contact surface between the first magnet 131 and the second magnet 132 in the cylindrical portion 43.

On the other hand, in the configuration of FIG. 24B, the magnetic material 133 is formed 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 it is provided, the magnetic body 133 allows the passage of magnetic flux. Therefore, magnetic saturation in the cylindrical portion 43 can be suppressed, and the proof stress against demagnetization is improved.

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

Further, the magnet magnetic path passing through the inside of the magnet becomes longer than that of the radial magnet in the conventional SPM rotor. Therefore, the magnet permeance can be increased, the magnetic force can be increased, and the torque can be increased. Further, the magnetic flux is concentrated in the center of the d-axis, so that the sine wave matching rate can be increased. In particular, if the current waveform is made into a sine wave or a trapezoidal wave by PWM control, or if a switching IC energized at 120 degrees is used, the torque can be increased 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 center of the magnetic pole in the magnet unit 42. Further, the radial thickness of the stator core 52 is preferably smaller than the radial thickness of the magnet unit 42. In this case, the magnet magnetic flux is about 1 [T], and the saturation magnetic flux density of the stator core 52 is 2 [T]. Therefore, the radial thickness of the stator core 52 is the radial thickness of the magnet unit 42. By setting the value to 1/2 or more of the above, it is possible to prevent magnetic flux leakage to the inner peripheral side of the stator core 52.

In a magnet having a Halbach structure or a polar anisotropic structure, since the magnetic path has a pseudo-arc shape, 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 through the stator core 52 does not exceed the magnetic flux in the circumferential direction. That is, when an iron-based metal having a saturation magnetic flux density of 2 [T] is used with respect to the magnetic flux of the magnet 1 [T], if the thickness of the stator core 52 is set to half or more of the magnet thickness, magnetic saturation is not preferably performed. It is possible to provide a small and lightweight rotary electric machine. Here, since the demagnetic 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 kept preferably high.

A modified example in which a part of the above configuration is modified will be described below.

(Modification example 1)
In the above embodiment, the outer peripheral surface of the stator core 52 is formed into a curved surface without unevenness, and a plurality of lead wire groups 81 are arranged side by side at predetermined intervals on the outer peripheral surface, but this may be changed. For example, as shown in FIG. 25, the stator core 52 includes an annular yoke 141 provided on both sides of the stator winding 51 in the radial direction opposite to the rotor 40 (lower side in the drawing). It has a protrusion 142 extending from the yoke 141 so as to project between the straight portions 83 adjacent to each other in the circumferential direction. The protrusions 142 are provided at predetermined intervals on the radial outer side of the yoke 141, that is, on the rotor 40 side. Each lead wire group 81 of the stator winding 51 is engaged with the protrusion 142 in the circumferential direction, and is arranged side by side in the circumferential direction while using the protrusion 142 as a positioning portion of the lead wire group 81. The protrusion 142 corresponds to a "member between conductors".

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

Further, a straight 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 radial thickness dimension of the protrusion 142 from the yoke 141 may be smaller than 1/2 of the radial thickness dimension of the straight portion 83.

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

According to the above configuration, the protrusion 142 has a limited thickness dimension in the radial direction and does not function as a teeth between the straight portions 83 adjacent to each other in the circumferential direction. Therefore, the teeth are formed between the straight portions 83. It is possible to bring the adjacent straight 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 the heat generated by the energization of the stator winding 51 can be reduced. In such a configuration, the absence of teeth makes it possible to eliminate magnetic saturation and increase the energizing current to the stator winding 51. In this case, it is possible to preferably 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 is radially shifted and has an interference avoidance portion that 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, heat dissipation can be improved even in the turn portion 84. As described above, it is possible to optimize the heat dissipation performance of the stator 50.

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 thickness dimension of the protrusion 142 in the radial direction is shown in FIG. 25. It is not tied to H1. Specifically, if the yoke 141 and the magnet unit 42 are separated by 2 mm or more, the radial thickness dimension of the protrusion 142 may be H1 or more in FIG. 25. For example, when the radial thickness dimension of the straight portion 83 exceeds 2 mm and the lead wire group 81 is composed of two layers of lead wires 82 inside and outside the radial direction, the straight portion 83 that is 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 second layer lead wire 82. In this case, if the radial thickness dimension of the protrusion 142 is up to "H1 x 3/2", the effect can be obtained not a little by increasing the cross-sectional area of the conductor in the conductor group 81.

Further, the stator core 52 may have the configuration shown in FIG. 26. 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 shown in a linearly developed manner.

In the configuration of FIG. 26, the stator 50 has a protrusion 142 as a member between the conductors between the conductors 82 (that is, the straight portion 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 a part 350 extending in the circumferential direction of the stator 50 is formed. Have. Assuming that the circumferential length of the stator 50 of this portion 350 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) is set. When Wt, 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 composed of a magnetic material that serves as.

The range Wn is set so as to include a plurality of lead wire groups 81 adjacent to each other in the circumferential direction and include a plurality of lead wire groups 81 having overlapping excitation times. At that time, it is preferable to set the center of the gap 56 of the lead 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 lead wire group 81 corresponds to the plurality of lead wire groups 81 in order from the one having the shortest distance from the magnetic pole center of the N pole in the circumferential direction. Then, the range Wn is set so as to include the four lead wire groups 81. At that 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 half of the protrusions 142 are included at both ends of the range Wn, the range Wn includes a total of four protrusions 142. 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, that is, the distance between the adjacent lead wire groups 81) is A, the total of the protrusions 142 included in the range Wn. 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 a distributed winding, and in the stator winding 51, the number of protrusions 142 with respect to one pole of the magnet unit 42, that is, each The number of gaps 56 between the lead wire groups 81 is "number of phases x Q". Here, Q is the number of the one-phase lead wires 82 that are in contact with the stator core 52. When the lead wires 82 are the lead wire groups 81 stacked in the radial direction of the rotor 40, it can be said that the number of the lead wires 82 is on the inner peripheral side of the one-phase lead 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 in one pole. Therefore, the total width dimension 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 the width of the protrusion 142 (that is, the gap 56) in the circumferential direction. Assuming that the dimension is A, "the number of excited phases x Q x A = 2 x 2 x A".

Then, after the total width dimension Wt is defined in this way, in the stator core 52, the protrusion 142 is configured as a magnetic material satisfying the relationship (1) above. The total width dimension Wt is also the circumferential dimension of the portion where the relative magnetic permeability can be larger than 1 in one pole. Further, in consideration of a margin, the total width dimension Wt may be set as the width dimension in the circumferential direction of the protrusion 142 at one magnetic pole. Specifically, since the number of protrusions 142 with respect to one pole of the magnet unit 42 is "number of phases x Q", the width dimension (total width dimension Wt) of the protrusions 142 in one magnetic pole in the circumferential direction is set to ". The number of phases × Q × A = 3 × 2 × A = 6A ”may be used.

The distributed winding referred to here is a one-pole pair period (N-pole and S-pole) of the magnetic poles, and has a one-pole pair of the stator winding 51. The one-pole pair of the stator winding 51 referred to here is composed of two straight portions 83 and a turn portion 84 in which currents flow in opposite directions and are electrically connected by the turn portion 84. If the above conditions are met, even if it is a short Pitch Winding, it is regarded as an equivalent of the distribution volume of the Full Pitch Winding.

Next, an example in the case of concentrated winding is shown. The centralized winding here means that the width of the one-pole pair of magnetic poles and the width of the one-pole pair of the stator winding 51 are different. As an example of concentrated winding, there are three lead wire groups 81 for one magnetic pole pair, three lead wire groups 81 for two magnetic pole pairs, and nine lead wire groups 81 for four magnetic pole pairs, and 5 Examples thereof include a case in which the lead wire group 81 has a relationship of nine with respect to one magnetic pole pair.

Here, when the stator winding 51 is a centralized winding, when the three-phase windings of the stator winding 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 dimension 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”. Then, after the width dimension Wt is defined in this way, the protrusion 142 is configured as a magnetic material satisfying the relationship (1) above. In the case of the concentrated winding shown above, the total width of the protrusions 142 in the circumferential direction of the stator 50 is set to A in the region surrounded by the conductors 81 of the same phase. Further, Wm in the concentrated winding corresponds to "the entire circumference of the surface of the magnet unit 42 facing the air gap" x "the number of phases" ÷ "the number of dispersions of the lead wire group 81".

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

Further, when the lead wire 82 includes the outer layer coating 182 as described later, the lead wire 82 may be arranged in the circumferential direction of the stator core 52 so that the outer layer coatings 182 of the lead 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.

In the configurations of FIGS. 25 and 26, the interlead wire member (projection 142) is disproportionately small with respect to the magnetic flux of the magnet on the rotor 40 side. The rotor 40 is a surface magnet type rotor having a low inductance and a flat surface, and has no reluctance in terms of magnetic resistance. In such a configuration, the inductance of the stator 50 can be reduced, the generation of magnetic flux distortion due to the deviation of the switching timing of the stator winding 51 is suppressed, and the electrolytic corrosion of the bearings 21 and 22 is suppressed. ..

(Modification 2)
The following configuration can also be adopted as the stator 50 using the inter-lead wire member satisfying the relationship of the above formula (1). In FIG. 27, a tooth-shaped portion 143 is provided as a member between the conductors on the outer peripheral surface side (upper surface side in the drawing) of the stator core 52. The dentate portions 143 are provided at predetermined intervals in the circumferential direction so as to protrude from the yoke 141, and have the same thickness dimension as the lead wire group 81 in the radial direction. The side surface of the dentate portion 143 is in contact with each lead wire 82 of the lead wire group 81. However, there may be a gap between the tooth-shaped portion 143 and each lead wire 82.

The dentate portion 143 is provided with a limitation on the width dimension in the circumferential direction, and is provided with polar teeth (statoth teeth) that are disproportionately thin with respect to the amount of magnets. With such a configuration, the dentate portion 143 is surely saturated by the magnetic flux of the magnet at 1.8 T or more, and the inductance can be lowered by lowering the permeance.

Here, in the magnet unit 42, assuming that 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, the surface area on the rotor side of each dentate portion 143 is St, the number per phase of the conducting wire 82 is m, and the dentate portions 143 for two phases are excited in one pole by energization of 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 dimensions of the tooth-shaped portion 143 so that the relationship of

When the magnet unit 42 and the toothed portion 143 have the same axial dimension, the width dimension of one pole of the magnet unit 42 in the circumferential direction is Wm, and the width dimension of the toothed portion 143 in the circumferential direction is Wst. Then, the above equation (2) is replaced with the equation (3).
Wst x m x 2 x Bs <Wm x Br ... (3)
More specifically, assuming that, for example, Bs = 2T, Br = 1T, and m = 2, 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 tooth-shaped 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 x m x 2" has a width dimension in the circumferential direction of the tooth-shaped 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 interlead wire member (dental portion 143) which is disproportionately small with respect to the magnetic flux of the magnet on the rotor 40 side is provided. In such a configuration, the inductance of the stator 50 can be reduced, the generation of magnetic flux distortion due to the deviation of the switching timing of the stator winding 51 is suppressed, and the electrolytic corrosion of the bearings 21 and 22 is suppressed. ..

(Modification 3)
In the above embodiment, the sealing member 57 covering the stator winding 51 is included in the radial outer side of the stator core 52 including all the lead wire groups 81, that is, the thickness dimension in the radial direction is the diameter of each lead wire group 81. The configuration is provided in a range larger than the thickness dimension in the direction, but this may be changed. For example, as shown in FIG. 28, the sealing member 57 is provided so that a part of the lead wire 82 protrudes. More specifically, the sealing member 57 is provided in a state where a part of the conducting wire 82, which is the outermost in the radial direction in the conducting wire group 81, is exposed on the radial outer side, that is, on the stator 50 side. In this case, the radial thickness dimension of the sealing member 57 may be the same as or smaller than the radial thickness dimension of each lead wire group 81.

(Modification example 4)
As shown in FIG. 29, in the stator 50, each lead wire group 81 may not be sealed by the sealing member 57. That is, the structure does not use the sealing member 57 that covers the stator winding 51. In this case, no inter-lead wire member is provided between the lead wire groups 81 arranged in the circumferential direction, and a gap is formed. In short, no interleading member is provided between the conducting wire groups 81 arranged in the circumferential direction. In addition, air may be regarded as a non-magnetic material or an equivalent of a non-magnetic material as Bs = 0, and air may be arranged in this void.

(Modification 5)
When the wire-to-lead member in the stator 50 is made of a non-magnetic material, a material other than resin can be used as the non-magnetic material. For example, a metal-based non-magnetic material may be used, such as using SUS304, which is an austenitic stainless steel.

(Modification 6)
The stator 50 may be configured not to include the stator core 52. In this case, the stator 50 is composed of the stator winding 51 shown in FIG. In the stator 50 that does not include the stator core 52, the stator winding 51 may be sealed with a sealing material. Alternatively, the stator 50 may be configured to include an annular winding holding portion 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, a plurality of magnets 91 and 92 arranged in the circumferential direction are used as the magnet unit 42 of the rotor 40, but this is changed and the magnet unit 42 is an annular permanent magnet. 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 having alternating polarities in the circumferential direction, and the magnet is integrally formed on both the d-axis and the q-axis. The annular magnet 95 is formed with an arcuate magnet magnetic path such that the direction of orientation is the radial direction on the d-axis of each magnetic pole and the direction of orientation is the circumferential direction on the q-axis between the magnetic poles.

In the annular magnet 95, the easy-magnetizing axis is parallel to the d-axis or close to parallel to the d-axis in the portion near the d-axis, and the easy-magnetizing axis is orthogonal to the q-axis or the q-axis in the portion near the q-axis. It suffices if the orientation is made so that an arcuate magnet magnetic path having a direction close to orthogonal is formed.

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

First, the processes 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. 31. The processing in each operation signal generation unit 116, 126, 130a, 130b is basically the same. Therefore, in the following, the processing of the operation signal generation unit 116 will be described 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 Sigma generated by the carrier generation unit 116a and the U, V, W phase command voltage calculated by the three-phase conversion unit 115 are input to the U, V, W phase comparators 116bU, 116bV, 116bW. To. The U, V, W phase command voltage has, for example, a sinusoidal waveform, and the phase is shifted by 120 ° depending on the electric angle.

The U, V, W phase comparators 116bU, 116bV, 116bW are U in the first inverter 101 by PWM (pulse width modulation) control based on the magnitude comparison between the U, V, W phase command voltage and the carrier signal Sigma. , V, W phase upper arm 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, W phase command voltage with the power supply voltage and the carrier signal. Generates operation signals for switches Sp and Sn. The driver 117 turns on / off 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 SignC, 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 low in the high torque region of the rotary electric machine 10. This setting is made in order to suppress a decrease 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 becomes low, the electrical time constant of the rotary electric machine 10 becomes small. 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 there is a concern that the current control diverges. The effect of this decrease in controllability can be more pronounced when the current flowing through the winding (for example, the effective value of the current) is included in the low current region than in the high current region. In order to deal with this problem, in this 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. 32. This process is repeatedly executed by the control device 110, for example, at a predetermined control cycle as the process of the operation signal generation unit 116.

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. Examples of the method for determining whether or not the product is included in the low current region include the following first and second methods.

<First method>
The torque estimation value of the rotary electric machine 10 is calculated based on the d-axis current and the q-axis current converted by the dq conversion unit 112. When it is determined that the calculated torque estimated 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 torque estimated value is equal to or more than the torque threshold value. , Judged as being included in the high current region. Here, the torque threshold value may be set to, for example, 1/2 of the starting torque (also referred to as restraint torque) of the rotary 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 greater 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, in the high rotation region. Here, the speed threshold value may be set to, for example, the rotation speed when the maximum torque of the rotary electric machine 10 becomes the torque threshold value.

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.

If a positive determination is made in step S10, the process proceeds to step S12, and the carrier frequency fc is set to the second frequency fH, which is 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 when it is included 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 in 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 in the low current region, so that the increase in current ripple due to the low inductance has a small 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 the inverters 101 and 102 can be reduced.

In this modified example, the following embodiments can be implemented.

When the carrier frequency fc is set to the first frequency fL and a positive 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. May be good.

Further, when the carrier frequency fc is set to the second frequency fH and a 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, a switch operation signal may be generated by space vector modulation (SVM) control. Even in this case, the above-mentioned change in switching frequency can be applied.

(Modification 9)
In each of the above embodiments, two pairs of lead wires for each phase constituting the lead wire group 81 are connected in parallel as shown in FIG. 33 (a). 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), the first and second conductors 88a and 88b may be connected in series as shown in FIG. 33 (b).

Further, three or more pairs of multilayer conductors may be laminated in the radial direction. FIG. 34 shows a configuration in which the first to fourth conductors 88a to 88d, which are four pairs of conductors, are laminated and arranged. The first to fourth conductors 88a to 88d are arranged in the radial direction in the order of the first, second, third, and fourth conductors 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. When connected in parallel, the current density of the conductors connected in parallel can be reduced, and heat generation during energization can be suppressed. 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 conductors 88a and 88b that are not connected in parallel come into contact with the unit base 61. The configuration is such that the third and fourth conductors 88c and 88d arranged in parallel on the stator core 52 side are arranged on the anti-stator core side. Thereby, the cooling performance of each of the conductors 88a to 88d in the multilayer conductor structure can be equalized.

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

(Modification example 10)
The rotary electric machine 10 may have an inner rotor structure (additional structure). In this case, for example, in the housing 30, it is preferable that the stator 50 is provided on the outer side in the radial direction and the rotor 40 is provided on the inner side in the radial direction. Further, it is preferable that the inverter unit 60 is provided on one side or both sides of both ends of the stator 50 and the rotor 40 in the axial direction. FIG. 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. 35.

The configurations of FIGS. 35 and 36, which are premised on the inner rotor structure, have the rotor 40 and the stator 50 reversed in the radial direction with respect to the configurations of FIGS. 8 and 9 which are premised on the outer rotor structure. Except for, it has the same configuration. Briefly, 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 interleading member is provided between each conducting wire portion in the circumferential direction, and as the interleading member, the width dimension of the interleading member at one magnetic pole in the circumferential direction is Wt, and the interleading member is saturated. When the magnetic flux density is Bs and the width dimension of the magnet unit at one magnetic pole in the circumferential direction 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, a member between the conductors is provided between the conductors in the circumferential direction, and a non-magnetic material is used as the member between the conductors.
(C) The stator 50 has a configuration in which no interlead wire member is provided between the lead wire portions in the circumferential direction.

The same applies to the magnets 91 and 92 of the magnet unit 42. That is, the magnet unit 42 is oriented so that the direction of the easy magnetization axis is parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, as compared with the q-axis side, which is the magnetic pole boundary. It is configured using. Details such as the magnetization directions 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 an inner rotor type, which is a drawing corresponding to FIG. 2 described above. The difference 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 interposed therebetween. Similar to FIG. 2, each of the bearings 21 and 22 is biased to one side in the axial direction with respect to the axial center of the rotor 40, whereby the rotor 40 is cantilevered and supported. There is. Further, an 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, the rotating shaft 11 is rotatably supported by bearings 21 and 22 in the housing 30, and the rotor 40 is fixed to the rotating shaft 11. Similar to the configuration shown in FIG. 2 and the like, the bearings 21 and 22 are arranged unevenly on either side in the axial direction with respect to the center in the axial direction of the rotor 40. The rotor 40 has a magnet holder 41 and a magnet unit 42.

The rotary electric machine 10 of FIG. 38 is different from the rotary electric machine 10 of 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 inside the magnet unit 42 in the radial direction. 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 as a rotary electric machine having an inner rotor structure will be described below. FIG. 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. Here, the vertical direction is shown with reference to the states of FIGS. 39 and 40.

As shown in FIGS. 39 and 40, the rotary electric machine 200 is rotatably arranged inside the stator core 201 and the stator 203 having an annular stator core 201 and a multi-phase stator winding 202. It is equipped with a rotor 204. The stator 203 corresponds to the armature and the rotor 204 corresponds to the field magnet. The stator core 201 is formed by laminating a large number of silicon steel plates, and a 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. Each of the magnet insertion holes is equipped with a permanent magnet magnetized so that the magnetization direction changes alternately for each adjacent magnetic pole. The permanent magnet of the magnet unit may have a Halbach array or a similar configuration as described in FIG. 23. Alternatively, the permanent magnet of the magnet unit has a pole in which the orientation direction (magnetization direction) extends in an arc shape between the d-axis which is the center of the magnetic pole and the q-axis which is the boundary of the magnetic poles as described with reference to FIGS. 9 and 30. It is preferable that the magnet has anisotropy characteristics.

Here, the stator 203 may have any of the following configurations.
(A) In the stator 203, an inter-lead wire member is provided between each lead wire portion in the circumferential direction, and as the inter-lead wire member, the width dimension of the inter-lead wire member at one magnetic pole in the circumferential direction is Wt, and the inter-lead wire member is saturated. When the magnetic flux density is Bs and the width dimension of the magnet unit at one magnetic pole in the circumferential direction 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, a member between the conductors is provided between the conductors in the circumferential direction, and a non-magnetic material is used as the member between the conductors.
(C) The stator 203 has a configuration in which no interlead wire member is provided between the lead wire portions in the circumferential direction.

Further, in the rotor 204, the magnet unit is oriented on the d-axis side, which is the center of the magnetic pole, so that the direction of the easy-magnetizing axis is parallel to the d-axis as compared with 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. Inside the inverter case 211, a plurality of power modules 212 constituting the inverter circuit, a smoothing capacitor 213 that suppresses voltage / current pulsation (ripple) generated by the switching operation of the semiconductor switching element, and a control board 214 having a control unit are provided. A current sensor 215 that detects the phase current and a resolver stator 216 that is a rotation speed sensor of the rotor 204 are provided. The power module 212 has an IGBT and a diode which are semiconductor switching elements.

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

On both sides of the stator core 201 in the axial direction, on the opposite side of the inverter case 211, a bearing unit 221 that rotatably holds the rotating shaft of the rotor 204 and an annular rear case 222 that houses the bearing unit 221 are provided. It is provided. The bearing unit 221 has, for example, a pair of bearings, and is arranged so as to be biased to either one of the axial directions with respect to the axial center of the rotor 204. However, a plurality of bearings in the bearing unit 221 may be provided so as to be dispersed on both sides in the axial direction of the stator core 201, and the rotating shaft may be supported by both bearings. The rotary electric machine 200 can be attached to the vehicle side by fastening the rear case 222 to the attachment portion of the vehicle such as a gear case or a transmission with bolts.

A cooling flow path 211a for flowing a refrigerant is formed in the inverter case 211. The cooling flow path 211a is formed by closing a space recessed in an annular shape 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 in the cooling flow path 211a. A cooling flow path 222a is also formed in the rear case 222 so as to surround the coil end of the stator winding 202. The cooling flow path 222a is formed by closing a space recessed in an annular shape from the upper surface of the rear case 222 with the lower surface of the stator core 201.

(Modification 12)
So far, the configuration embodied in the rotating field type rotating electric machine has been described, but it is also possible to change this and embody it in the rotating armature type rotating electric machine. FIG. 41 shows the configuration of the 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 by impregnating a porous metal with oil. A rotor 234 as an armature is fixed to the rotating shaft 233. The rotor 234 has a rotor core 235 and a polyphase rotor winding 236 fixed to the outer peripheral portion thereof. In the rotor 234, the rotor core 235 has a slotless structure, and the rotor winding 236 has a flat conducting 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.

Further, a stator 237 as a field magnet is provided on the radial outer side 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 has a configuration including a plurality of magnetic poles having alternating polarities in the circumferential direction, and is a magnetic pole boundary on the d-axis side, which is the center of the magnetic poles, like the magnet unit 42 described above. It is configured so that the direction of the easily magnetized axis is parallel to the d-axis as compared with the side of the axis. The magnet unit 239 has an oriented sintered neodymium magnet, the intrinsic coercive force thereof is 400 [kA / m] or more, and the residual magnetic flux density is 1.0 [T] or more.

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

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 thereof. The commutator 241 is electrically connected to the rotor winding 236 via a lead 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 lead 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 electrical wiring, or may be connected to a DC power source via a terminal block or the like.

The rotary shaft 233 is provided with a resin washer 244 as a sealing material between the bearing 232 and the commutator 241. The resin washer 244 suppresses the oil seeping out 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 rotary electric machine 10, each conducting wire 82 may have a plurality of insulating coatings inside and outside. For example, it is preferable to bundle a plurality of conductive wires (wires) with an insulating coating into one and cover it with an outer layer coating to form the conductive wire 82. In this case, the insulating coating of the wire constitutes the inner insulating coating, and the outer layer coating constitutes the outer insulating coating. Further, in particular, it is preferable that the insulating capacity of the outer insulating coating among the plurality of insulating coatings on the lead wire 82 is higher than the insulating capacity of the inner insulating coating. Specifically, the thickness of the outer insulating film is made thicker than the thickness of the inner insulating film. 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 coating may be used as the outer insulating coating. At least one of these may be applied. It is preferable that the strands are configured as an aggregate of a plurality of conductive materials.

By strengthening the insulation of the outermost layer of the lead wire 82 as described above, it becomes suitable for use in a high voltage vehicle system. Further, even in highlands where the atmospheric pressure is low, the rotary electric machine 10 can be properly driven.

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

In FIG. 42, the lead wires 82 are a plurality of (four in the figure) strands 181 and, for example, a resin outer layer coating 182 (outer insulating coating) surrounding the plurality of strands 181 and each element in the outer layer coating 182. It has an intermediate layer 183 (intermediate insulating film) filled around the wire 181. The wire 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 layer coating 182 insulates the phases. It is preferable that the strand 181 is configured as an aggregate of a plurality of conductive materials.

The intermediate layer 183 has a coefficient of linear expansion higher than that of the conductor coating 181b of the wire 181 and a coefficient of linear expansion lower than that of the outer layer coating 182. That is, in the lead wire 82, the coefficient of linear expansion 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 an intermediate layer 183 having an intermediate 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 conducting wire 82, the conductive portion 181a and the conductor coating 181b are adhered to each other in the wire 181 and the conductor coating 181b and the intermediate layer 183 and the intermediate layer 183 and the outer layer coating 182 are adhered to each other. Then, the adhesive strength becomes weaker toward the outside of the conductor 82. That is, the adhesive strength of the conductive portion 181a and the conductor coating 181b is weaker than the adhesive strength of the conductor coating 181b and the intermediate layer 183 and the adhesive strength of the intermediate layer 183 and the outer layer coating 182. Further, comparing the adhesive strength of the conductor coating 181b and the intermediate layer 183 with the adhesive strength of the intermediate layer 183 and the outer layer coating 182, it is preferable that the latter (outer side) is weaker or equivalent. The magnitude of the adhesive strength between the coatings can be grasped from, for example, the tensile strength required when peeling off the two layers of coatings. By setting the adhesive strength of the lead wire 82 as described above, it is possible to suppress cracking (co-cracking) on both the inner layer side and the outer layer side even if an internal / external temperature difference occurs due to heat generation or cooling. ..

Here, the heat generation and temperature change of the rotary electric machine mainly occur as a copper loss generated from the conductive portion 181a of the wire 181 and an iron loss generated from the inside of the iron core, and these two types of losses occur in the conducting wire 82. It is transmitted from the outside of the conductive portion 181a or the conducting wire 82, and the intermediate layer 183 does not have a heat generating source. In this case, since the intermediate layer 183 has an adhesive force that can serve as a cushion for both, simultaneous cracking can be prevented. Therefore, suitable use is possible even when used in fields with high withstand voltage or large temperature changes such as vehicle applications.

It is supplemented below. The strand 181 may be, for example, an enamel wire, and in such a case, it has a resin coating layer (conductor coating 181b) such as PA, PI, and PAI. Further, it is desirable that the outer layer coating 182 outside the wire 181 is made of the same PA, PI, PAI, etc., and has a large thickness. As a result, 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 such as PPS, PEEK, fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, and LCP, in addition to those made by thickening the materials such as PA, PI, and PAI. It is also desirable to use one smaller than PI and PAI in order to increase the conductor density of the rotating machine. With these resins, even if they are thinner than the PI and PAI coatings equivalent to the conductor coating 181b or the thickness equivalent to the conductor coating 181b, their dielectric strength can be increased, thereby occupying the conductive portion. Can be increased. In general, the resin has better insulation than the insulating coating of enamel wire with a dielectric constant. Naturally, there are cases where the dielectric constant is deteriorated depending on the molding state and the mixture. Among them, PPS and PEEK are suitable as the outer layer coating of the second layer because their linear expansion coefficient is generally larger than that of the enamel coating but smaller than that of other resins.

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

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 of a resin in which the insulating layer of the wire 181 and the two types of coatings are different, the thermal stress and 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 wire (enamel wire) and a gap 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 having a low dielectric constant made of epoxy or the like and having a low coefficient of linear expansion. By doing so, it is possible to suppress not only the mechanical strength but also the destruction of the coating film due to friction caused by the vibration of the conductive portion or the destruction of the outer layer coating film due to the difference in linear expansion coefficient.

Formability of epoxy, PPS, PEEK, LCP, etc. is used as the outermost layer fixing, which is generally the final step around the stator winding, which is responsible for mechanical strength, fixing, etc. to the lead wire 82 having the above configuration. A resin having properties such as dielectric constant and linear expansion coefficient similar to those of an enamel coating is preferable.

Generally, resin potting with urethane or silicon is usually performed, but the linear expansion coefficient of the resin is almost twice as large as that of other resins, and thermal stress capable of shearing the resin is generated. Therefore, it is not suitable for applications of 60V or higher, which are used internationally due to strict insulation regulations. In this regard, according to the final insulation step easily made by injection molding or the like using epoxy, PPS, PEEK, LCP or the like, each of the above requirements can be achieved.

Modification examples other than the above are listed below.

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

As a rotary electric machine having a slotless structure, a small-scale rotary electric machine having an output of several tens of watts to several hundreds of watts is known. The inventor of the present application does not know the case where the slotless structure is generally adopted in a large industrial rotary electric machine having a speed of more than 10 kW. The inventor of the present application examined the reason.

In recent years, the mainstream rotary electric machines are roughly classified into the following four types. These rotary electric motors are a brushed motor, a basket type induction motor, a permanent magnet type synchronous motor, and a reluctance motor.

An exciting current is supplied to the brushed motor through the brush. For this reason, in the case of a motor with a brush of a large machine, the brush becomes large and maintenance becomes complicated. As a result, with the remarkable development of semiconductor technology, it has been replaced by brushless motors such as induction motors. On the other hand, in the world of small motors, coreless motors are also supplied to the world because of their low inertia and economic advantages.

In a cage-type induction motor, a magnetic field generated by the stator winding on the primary side is received by the iron core of the rotor on the secondary side, and an induced current is intensively passed through the cage-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 core on both the stator side and the rotor side.

The reluctance motor is a motor that utilizes the reluctance change of the iron core, and it is not desirable to eliminate the iron core in principle.

In recent years, IPMs (that is, embedded magnet type rotors) have become the mainstream of permanent magnet synchronous motors, and in large machines in particular, IPMs are often used unless there are special circumstances.

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

According to the analysis of the inventor of the present application, the torque on the surface of the rotor that generates the magnet torque and the reluctance torque is measured by the radial distance DM between the surface of the magnet unit on the armature side and the axis of the rotor, that is, The radius of the stator core of a general inner rotor is drawn with the horizontal axis as shown in FIG. 43.

The potential of the magnet torque is determined by the magnetic field strength generated by the permanent magnet as shown in the following equation (eq1), whereas the reluctance torque is determined by the inductance, especially q, as shown in the following equation (eq2). The magnitude of the shaft 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 will be the surface area of the cylinder. Strictly speaking, since there are N pole and S pole, it is proportional to the occupied area of half of 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 depends on the shape of the iron core, but its sensitivity is low, and rather it is proportional to the square of the number of turns of the stator winding, so that the number of turns is highly dependent. 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 L = μ · N ^ 2 × 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, since the slot shape is substantially quadrangular, the slot area is proportional to the product a × b of the circumferential length dimension a and the radial length dimension b.

The circumferential length dimension of the slot is proportional to the diameter of the cylinder because it increases as the diameter of the cylinder increases. The radial length dimension of the slot is exactly proportional to the diameter of the cylinder. That is, the slot area is proportional to the square of the diameter of the cylinder. Also, 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 electric machine is determined by how large the current can flow, and that 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 plotting the relationship between the magnet torque and the reluctance torque and DM.

As shown in FIG. 43, the magnet torque increases linearly 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 the DM is relatively small, and the reluctance torque is dominant as the stator core radius increases. The inventor of the present application has concluded 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 10 kW class motor whose stator core radius sufficiently exceeds 50 mm because it is the current mainstream to utilize reluctance torque, and this is the field of large machines. It is presumed to be one of the reasons why the slotless structure is not adopted.

In the case of a rotary electric machine in which an iron core is used for the stator, magnetic saturation of the iron core is always an issue. In particular, in a radial gap type rotary electric machine, the vertical cross-sectional shape of the rotating shaft is a fan shape per magnetic pole, and the magnetic path width becomes narrower toward the inner peripheral side of the device, and the inner peripheral side dimension of the teeth part forming the slot is the performance of the rotary electric machine. Set limits. No matter how high-performance permanent magnets are used, if magnetic saturation occurs in this part, the performance of the permanent magnets cannot be fully brought out. In order to prevent magnetic saturation from occurring in this part, the inner circumference must be designed to be large, resulting in an increase in the size of the equipment.

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

From the above, we would like to abolish the teeth in order to eliminate magnetic saturation in a rotary electric machine with a slotless structure in which the DM is 50 mm or more. However, when the teeth are abolished, the magnetic resistance of the magnetic circuit 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, in the above-mentioned rotary electric machine having a slotless structure in which the DM is 50 mm or more, there is room for improvement in increasing the torque. Therefore, there is a great merit of applying the above-mentioned configuration capable of increasing torque to the rotary electric machine having a slotless structure in which the DM is 50 mm or more.

Not only the rotary electric machine having an outer rotor structure but also the rotary electric machine having an inner rotor structure has a distance DM of 50 mm or more 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. You may be.

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

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

-In the rotary electric machine 10 having the above configuration, the bearings 21 and 22 are configured to use non-conductive grease, but this may be changed to a configuration in which the bearings 21 and 22 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 rotating shaft 11, bearings may be provided at two locations on one end side and the other end side in the axial direction of the rotor 40. In this case, in the configuration of FIG. 1, bearings may be provided at two locations on one end side and the other end side of the inverter unit 60.

In the rotary electric machine 10 having the above configuration, in the rotor 40, the intermediate portion 45 of the magnet holder 41 has an inner shoulder portion 49a and an emotional outer shoulder portion 49b, but these shoulder portions 49a and 49b are eliminated and the rotor portion 40 is flat. It may be configured to have various surfaces.

In the rotary electric machine 10 having the above configuration, the conductor 82a is configured as an aggregate of a plurality of strands 86 in the conductor 82 of the stator winding 51, but this is changed and a square conductor having a rectangular cross section is used as the conductor 82. It may be configured. Further, the lead wire 82 may be configured to use a round lead wire having a circular cross section or an elliptical cross section.

-In the rotary electric machine 10 having the above configuration, the inverter unit 60 is provided inside the stator 50 in the radial direction, but instead of this, the inverter unit 60 may not be provided inside the stator 50 in the radial direction. .. In this case, it is possible to set an internal region inside the stator 50 in the radial direction as a space. Further, it is possible to arrange parts different from the inverter unit 60 in the internal region.

-The rotary electric machine 10 having the above configuration may not include 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 an in-wheel motor for a vehicle)
Next, an embodiment in which the rotary electric machine is provided integrally with the wheels of the vehicle as an in-wheel motor will be described. 45 is a perspective view showing the wheel 400 having an in-wheel motor structure and its peripheral structure, FIG. 46 is a vertical 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 figures is a perspective view of the wheel 400 as viewed from the inside of the vehicle. In the vehicle, the in-wheel motor structure of the present embodiment can be applied in various forms. For example, in a vehicle having two wheels in the front and rear of the vehicle, two wheels on the front side of the vehicle and two wheels on the rear side of the vehicle. It is possible to apply the in-wheel motor structure of the present embodiment to two wheels or four wheels in front of and behind the vehicle. However, it can also be applied to a vehicle in which at least one of the front and rear of the vehicle is one wheel. The in-wheel motor is an application example as a vehicle drive unit.

As shown in FIGS. 45 to 47, the wheel 400 is fixed to, for example, the tire 401, which is a well-known pneumatic tire, the wheel 402 fixed to the inner peripheral side of the tire 401, and the inner peripheral side of the wheel 402. It is equipped with a rotary electric machine 500. The rotary electric machine 500 has a fixed portion which is a portion including a stator (stator) and a rotating portion which is a portion including a rotor (rotor), and the fixed portion is fixed to the vehicle body side and the rotating portion is formed. It is fixed to the wheel 402, and the tire 401 and the wheel 402 rotate due to the rotation of the rotating portion. The detailed configuration of the rotary electric machine 500 including the fixed portion and the rotating portion will be described later.

Further, as peripheral devices, a suspension device for holding the wheels 400 with respect to a vehicle body (not shown), a steering device for changing the direction of the wheels 400, and a braking device for braking the wheels 400 are attached to the wheels 400. Has been done.

The suspension device is an independent suspension type suspension, and any type such as a trailing arm type, a strut type, a wishbone type, and a multi-link type can be applied. In the present 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, for example, a shock absorber. However, the detailed illustration is omitted. The lower arm 411 and the suspension arm 412 are each connected to the vehicle body side and to a disk-shaped base plate 405 fixed to a fixed portion of the rotary electric machine 500. As shown in FIG. 46, the lower arm 411 and the suspension arm 412 are supported on the rotary electric machine 500 side (base plate 405 side) by the support shafts 414 and 415 in a coaxial state with each other.

Further, as the steering device, for example, a rack & pinion type structure, a ball & nut type structure, a hydraulic power steering system, and an electric power steering system can be applied. In the present embodiment, a rack device 421 and a tie rod 422 are provided as steering devices, 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 operates with the rotation of the steering shaft (not shown), the tie rod 422 moves in the left-right direction of the vehicle. As a result, the wheel 400 rotates around the support shafts 414 and 415 of the lower arm 411 and the suspension arm 412, and the wheel direction is changed.

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

Further, the wheel 400 is attached with an accommodation duct 440 that accommodates the electric wiring H1 extending from the rotary electric machine 500 and the cooling pipe H2. The accommodating duct 440 extends from the end of the rotary electric machine 500 on the fixed portion side along the end surface of the rotary electric machine 500 and is provided so as to avoid the suspension arm 412, and is fixed to the suspension arm 412 in that state. As a result, the connection portion 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 stress caused by vibration of the vehicle in the electric wiring H1 and the cooling pipe H2. The electrical wiring H1 is connected to an in-vehicle power supply unit and 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 the 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 operating efficiency and output as compared with the motor of a vehicle drive unit having a speed reducer as in the prior art. That is, if the rotary electric machine 500 is adopted in an application in which a practical price can be realized by reducing the cost as compared with the conventional technology, it may be used as a motor for an application other than the vehicle drive unit. Even in such a case, the excellent performance is exhibited as in the case of applying it to an in-wheel motor. The operating efficiency refers to an index used at the time of a test in a driving mode that derives the fuel efficiency of the vehicle.

The outline of the rotary electric machine 500 is shown in FIGS. 48 to 51. FIG. 48 is a side view of the rotary electric machine 500 as viewed 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 (cross-sectional view taken along lines 49-49 of FIG. 48). 50 is a cross-sectional view of the rotary electric machine 500 (a cross-sectional view taken along the line 50-50 of FIG. 49), and FIG. 51 is an exploded cross-sectional view of the components of the rotary electric machine 500. In the following description, in FIG. 51, the direction in which the rotary shaft 501 extends outward of the vehicle body is the axial direction, the direction extending radially from the rotary shaft 501 is the radial direction, and in FIG. 48, the center of the rotary shaft 501, in other words. For example, the circumferential direction is defined as two directions extending in a circumferential shape from any point other than the rotation center of the rotating portion on the center line drawn to form a cross section 49 passing through the rotation center of the rotating portion. 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. Further, from the vehicle mounted state, the right side is the outside of the vehicle and the left side is the inside of the vehicle in FIG. 49. In other words, from the vehicle-mounted state, the rotor 510, which will be described later, is arranged in the outer direction 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 classified into a rotor 510, a stator 520, an inverter unit 530, a bearing 560, and a rotor cover 670. Each of these members is arranged coaxially with respect to the rotating shaft 501 integrally provided on the rotor 510, and is assembled in the axial direction in a predetermined order to form the rotating electric machine 500.

In the rotary electric machine 500, the rotor 510 and the stator 520 each have a cylindrical shape, and are arranged so as to face each other with an air gap in between. As the rotor 510 rotates integrally with the rotating shaft 501, the rotor 510 rotates on the radial outer side of the stator 520. The rotor 510 corresponds to the "field magnet" and the stator 520 corresponds to the "armature".

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

The rotor carrier 511 has a cylindrical portion 513. A magnet unit 512 is fixed to the inner peripheral surface of the cylindrical portion 513. That is, the magnet unit 512 is provided in a state of being 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 facing each other in the axial direction thereof. The first end is located in the direction outside the vehicle body, and the second end is located in the direction in which the base plate 405 is present. 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 integral structure. The second end of the cylindrical portion 513 is open. The rotor carrier 511 is formed of, for example, a cold-rolled steel plate having sufficient mechanical strength (SPCC or SPHC thicker than SPCC), forging steel, carbon fiber reinforced plastic (CFRP), or the like.

The axial length of the rotating shaft 501 is longer than the axial dimension of the rotor carrier 511. In other words, the rotating shaft 501 projects toward the open end side (inward direction of the vehicle) of the rotor carrier 511, and the above-mentioned braking device or the like is attached to the protruding end side.

A through hole 514a is formed in the central portion of the end plate 514 of the rotor carrier 511. The rotating shaft 501 is fixed to the rotor carrier 511 in a state of being inserted into the through hole 514a of the end plate 514. The rotating shaft 501 has a flange 502 extending in a direction intersecting (orthogonal) in the axial direction at a portion where the rotor carrier 511 is fixed, and the flange and the outer surface of the end plate 514 are surface-joined. In this state, the rotation shaft 501 is fixed to the rotor carrier 511. In the wheel 400, the wheel 402 is fixed by using fasteners such as bolts erected from the flange 502 of the rotating shaft 501 toward the outside of the vehicle.

Further, the magnet unit 512 is composed of a plurality of permanent magnets arranged so that the polarities are alternately changed along the circumferential direction of the rotor 510. As a result, 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, for example, adhesion. The magnet unit 512 has the configuration described as the magnet unit 42 in FIGS. 8 and 9 of the first embodiment, and as a permanent magnet, has an intrinsic coercive force of 400 [kA / m] or more and a residual magnetic flux. It is constructed by using sintered neodymium magnets having a density Br of 1.0 [T] or more.

Similar to the magnet unit 42 shown in FIG. 9, the magnet unit 512 has a first magnet 91 and a second magnet 92, which are polar anisotropic magnets and have different polarities. As described with reference to FIGS. 8 and 9, in each of the magnets 91 and 92, the orientation of the easy axis of magnetization is different between the d-axis side (the portion closer to the d-axis) and the q-axis side (the portion closer to the q-axis). On the d-axis side, the direction of the easy-to-magnetize axis is close to the direction parallel to the d-axis, and on the q-axis side, the direction of the easy-to-magnetize axis is close to the direction orthogonal to the q-axis. Then, an arcuate magnet magnetic path is formed by the orientation according to the direction of the easily magnetized axis. In each of the magnets 91 and 92, the easy magnetization axis may be oriented parallel to the d-axis on the d-axis side, and the easy-magnetization axis may be oriented orthogonal to the q-axis on the q-axis side. In short, the magnet unit 512 is configured so that the direction of the easy magnetization axis is parallel to the d-axis on the d-axis side, which is the center of the magnetic pole, as compared with the q-axis side, which is the magnetic pole boundary. ..

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

The magnet unit 512 has a rotor core (back yoke) formed by laminating a plurality of electromagnetic steel sheets in the axial direction on the side of the cylindrical portion 513 of the rotor carrier 511, that is, on the outer peripheral surface side. May be good. That is, it is also possible to provide the rotor core on the radial inside of the cylindrical portion 513 of the rotor carrier 511 and to provide the permanent magnets (magnets 91, 92) on the radial inside of the rotor core.

As shown in FIG. 47, the cylindrical portion 513 of the rotor carrier 511 is formed with recesses 513a in a direction extending in the axial direction at predetermined intervals in the circumferential direction. 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 in accordance with the convex portion 513b of the cylindrical portion 513, and the convex portion 513b of the cylindrical portion 513 enters the concave portion 512a, whereby the magnet unit 512 The displacement in the circumferential direction of the magnet is suppressed. That is, the convex portion 513b on the rotor carrier 511 side functions as a detent 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 direction of the magnetic path of the magnet in the magnet unit 512 is indicated by an arrow. 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 to or close to parallel to the d-axis. The magnet unit 512 is formed with recesses 512b at positions corresponding to the q-axis on the inner peripheral surface side thereof. In this case, in the magnet unit 512, the length of the magnet magnetic path differs between the side closer to the stator 520 (lower side in the figure) and the side farther from the stator 520 (upper side in the figure), and the side closer to the stator 520 is magnetized. The path length is shortened, and the recess 512b is formed at a position where the 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 the place where the magnet magnetic flux is weak.

Here, the effective magnetic flux density Bd of the magnet becomes higher as the length of the magnetic circuit passing through the inside of the magnet becomes longer. Further, the permeance coefficient Pc and the effective magnetic flux density Bd of the magnet are in a relationship that the higher one is, the higher the other is. According to the configuration of FIG. 52, the amount of magnets can be reduced while suppressing a decrease in the permeance coefficient Pc, which is an index of the height of the effective magnetic flux density Bd of the magnet. In the BH coordinates, the intersection of the permeance straight line and the demagnetization curve according to the shape of the magnet is the operating point, and the magnetic flux density at the operating point is the effective magnetic flux density Bd of the magnet. The rotary electric machine 500 of the present embodiment has a configuration in which the amount of iron in the stator 520 is reduced, and in such a configuration, a method of setting a magnetic circuit straddling the q-axis is extremely effective.

Further, 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 configuration of the stator 520 will be described. The stator 520 has a stator winding 521 and a stator core 522. FIG. 53 is a perspective view showing the stator winding 521 and the stator core 522 in an exploded manner.

The stator winding 521 is composed of a plurality of phase windings formed by winding in a substantially tubular shape (annular shape), and a stator core 522 as a base member is assembled inside the stator winding 521 in the radial direction. There is. In the present embodiment, the stator winding 521 is configured as a three-phase phase winding by using U-phase, V-phase, and W-phase phase windings. Each phase winding is composed of two inner and outer layers of lead wires 523 in the radial direction. The stator 520 is characterized by having a slotless structure and a flat conducting wire structure of the stator winding 521, similarly to the stator 50 described above, and the stator 50 shown in FIGS. 8 to 16 It has a similar or similar configuration.

The configuration 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 sheets are laminated in the axial direction and has a predetermined thickness in the radial direction, and the stator core 522 has a shape. The stator winding 521 is assembled on the outer side in the radial direction on the rotor 510 side. The outer peripheral surface of the stator core 522 has a curved surface without unevenness, and when the stator winding 521 is assembled, the lead wire 523 constituting 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 interleading member is provided between each conducting wire 523 in the circumferential direction, and as the interleading member, the width dimension of the interleading member in one magnetic pole in the circumferential direction is Wt, and the interleading member is saturated. When the magnetic flux density is Bs, the width dimension of the magnet unit 512 at one magnetic pole in the circumferential direction 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, a member between the conductors is provided between the conductors 523 in the circumferential direction, and a non-magnetic material is used as the member between the conductors.
(C) The stator 520 has a configuration in which no interleading member is provided between the conducting wires 523 in the circumferential direction.

According to the configuration of the stator 520, the inductance is higher than that of a rotating electric machine having a general teeth structure in which a tooth (iron core) for establishing a magnetic path is provided between each conducting wire portion as a stator winding. It will be reduced. Specifically, it is possible to reduce the inductance to 1/10 or less. In this case, since the impedance decreases as the inductance decreases, the output power with respect to the input power of the rotary electric machine 500 can be increased, which in turn can contribute to the increase in torque. In addition, it is possible to provide a rotary electric machine with a higher output than a rotary electric machine using an embedded magnet type rotor that outputs torque 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 together with the stator core 522 by a molding material (insulating member) made of resin or the like, and the molding material is formed between the conductive wires 523 arranged in the circumferential direction. It has an intervening configuration. Based on this configuration, the stator 520 of the present embodiment corresponds to the configuration of (B) among the above (A) to (C). Further, the conductive wires 523 adjacent to each other in the circumferential direction are arranged so that the end faces in the circumferential direction are in contact with each other or are arranged close to each other at a minute interval, which is the configuration of (C) above in terms of this configuration. May be good. When adopting the configuration of the above (A), the stator core 522 is aligned with the orientation of the lead wire 523 in the axial direction, that is, according to the skew angle of the stator winding 521 having a skew structure, for example. It is preferable that a protrusion is provided on the outer peripheral surface.

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

The stator winding 521 is formed to be wound in an annular shape by distributed winding. In the stator winding 521, the wire rod is wound around the inner and outer two layers in the radial direction, and the wire wires 523 on the inner layer side and the outer layer side are skewed in different directions (FIG. 54 (a), FIG. See FIG. 54 (b)). Each lead wire 523 is insulated from each other. The lead wire 523 may be configured as an aggregate of a plurality of strands 86 (see FIG. 13). Further, for example, two lead wires 523 having the same phase and the same energization direction are provided side by side in the circumferential direction. In the stator winding 521, one lead wire portion having the same phase is formed by each lead wire 523 having two layers in the radial direction and two wires in the circumferential direction (that is, a total of four wires), and the lead wire portions are one by one in one magnetic pole. It is provided.

It is desirable that the thickness dimension of the conductor portion in the radial direction be smaller than the width dimension in the circumferential direction of one phase in one magnetic pole, whereby the stator winding 521 has a flat conductor structure. Specifically, for example, in the stator winding 521, one lead wire portion having the same phase may be formed by each lead wire 523 having two layers in the radial direction and four wires in the circumferential direction (that is, a total of eight wires). Alternatively, in the cross section of the conductor 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. As the stator winding 521, the stator winding 51 shown in FIG. 12 can also be used. However, in this case, it is necessary to secure a space in the rotor carrier 511 for accommodating the coil end of the stator winding.

In the stator winding 521, the lead wires 523 are arranged side by side in the circumferential direction at the coil side 525 that overlaps the stator core 522 in the radial direction at a predetermined angle, and is axially outside the stator core 522. The coil ends 526 on both sides are inverted (folded back) inward in the axial direction to form a continuous connection. FIG. 54A shows a range of the coil side 525 and a range of the coil end 526, respectively. The inner layer side lead wire 523 and the outer layer side lead wire 523 are connected to each other at the coil end 526, so that the lead wire 523 is rotated each time the lead wire 523 is axially inverted (each time it is folded back) at the coil end 526. The inner layer side and the outer layer side are switched alternately. In short, the stator winding 521 has a configuration in which 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 that are continuous in the circumferential direction.

Further, in the stator winding 521, two types of skews are applied in which the skew angles are different 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 lead wire 523, the skew angle θs1 in the central region and the skew angle θs2 in the end region are different, and the skew angle θs1 is smaller than the skew angle θs2. In the axial direction, the end region is defined to include the coil side 525. The skew angle θs1 and the skew angle θs2 are inclination angles at which each lead wire 523 is inclined with respect to the axial direction. The skew angle θs1 in the central region may be set in an angle range appropriate for reducing the harmonic component of the magnetic flux generated by the energization of the stator winding 521.

The coil end 526 is reduced by making the skew angle of each lead wire 523 in the stator winding 521 different 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. However, the winding coefficient of the stator winding 521 can be increased. In other words, the length of the coil end 526, that is, the lead wire length of the portion protruding in the axial direction from the stator core 522 can be shortened while ensuring a desired winding coefficient. As a result, it is possible to improve the torque while reducing the size of the rotary electric machine 500.

Here, an appropriate range as the skew angle θs1 in the central region will be described. When X lead wires 523 are arranged in one magnetic pole in the stator winding 521, it is conceivable that the Xth harmonic component is generated by energization of the stator winding 521. When the number of phases is S and the logarithm is m, X = 2 × S × m. The inventor of the present application considers that the X-th order harmonic component is a component that constitutes a composite wave of the X-1st-order harmonic component and the X + 1-th order harmonic component, and therefore is the X-1st-order harmonic component or X + 1 It was noted that the Xth harmonic component can be reduced by reducing at least one of the following harmonic components. Based on this focus, the inventor of the present application sets the skew angle θs1 within the angle range of “360 ° / (X + 1) to 360 ° / (X-1)” in terms of the electric angle, so that the Xth harmonic component It was found that can be reduced.

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

By setting the skew angle θs1 in the central region as described above, the magnet magnetic fluxes alternating with NS can be positively interlocked in the central region, and the winding coefficient of the stator winding 521 is increased. be able to.

The skew angle θs2 in the end region is larger than the skew angle θs1 in the central region 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 lead wire 523 and the outer layer side lead wire 523 may be connected by welding or adhesion between the ends of the respective lead 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 each coil end 526 on both sides in the axial direction. It is configured to be connected to. Therefore, here, the configuration in which the lead wires are connected to each other at the coil end 526 will be described while distinguishing between the coil end 526 on the bus bar connection side and the coil end 526 on the opposite side.

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

The second configuration is such that each lead wire 523 is connected by means other than welding at the coil end 526 on the bus bar connection side, and each lead wire 523 is connected by welding at the coil end 526 on the opposite side. In this case, if the coil end 526 on the bus bar connection side is configured to connect each lead wire 523 by welding, the separation distance between the bus bar and the coil end 526 is sufficient to avoid contact between the welded portion and the bus bar. However, with this configuration, the separation distance between the bus bar and the coil end 526 can be reduced. Thereby, the regulation regarding the length of the stator winding 521 in the axial direction or the bus bar can be relaxed.

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

As a fourth configuration, the coil ends 526 on both sides in the axial direction are connected to each lead wire 523 by means other than welding. In this case, the portion of the stator winding 521 to be welded can be reduced as much as possible, and the concern that insulation peeling may occur in the welding process can be reduced.

Further, in the step of manufacturing the annular stator winding 521, it is preferable to manufacture the strip-shaped windings arranged in a plane shape, and then to form the strip-shaped windings in an annular shape. In this case, it is preferable to weld the conducting wires at the coil end 526 in a state where the winding is a flat strip-shaped winding. When forming a flat band-shaped winding in an annular shape, it is preferable to use a cylindrical jig having the same diameter as the stator core 522 and wind the strip-shaped winding around the cylindrical jig to form the band-shaped winding in an annular shape. Alternatively, the strip winding may be wound directly around the stator core 522.

It is also possible to change the configuration of the stator winding 521 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.

Further, in the stator windings 521 shown in FIGS. 54 (a) and 54 (b), the ends of the in-phase lead wires 523 adjacent to each other in the circumferential direction are connected by a crossover portion extending in a direction orthogonal to the axial direction. It may be.

The number of layers of the stator winding 521 may be 2 × n layers (n is a natural number), and the stator winding 521 may have 4 layers, 6 layers, or the like in addition to the 2 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 sectional views of the inverter unit 530. In FIG. 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 to the inverter housing 531 and a bus bar module 533 for electrically connecting each of the electric modules 532.

The inverter housing 531 has a cylindrical outer wall member 541, an inner wall member 542 having an outer peripheral diameter smaller than that of the outer wall member 541 and arranged inside the outer wall member 541 in the radial direction, 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, made of 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 overlapped and combined in the radial direction inside and outside, and the boss forming member 543 is assembled on one end side in the axial direction of the inner wall member 542. The assembled state is the state shown in FIG. 57.

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

As shown in FIG. 56, the outer wall member 541 is formed with a plurality of recesses 541a, 541b, 541c on the inner peripheral surface thereof, and the inner wall member 542 has a plurality of recesses 542a, 542b, 542c on the outer peripheral surface thereof. Is formed. Then, by assembling the outer wall member 541 and the inner wall member 542 to each other, three hollow portions 544a, 544b, and 544c are formed between them (see FIG. 57). Of these, the central hollow portion 544b is used as a cooling water passage 545 for circulating cooling water as a refrigerant. Further, the sealing material 546 is housed in the hollow portions 544a and 544c on both sides of the hollow portion 544b (cooling water passage 545). The hollow portion 544b (cooling water passage 545) is sealed by the sealing material 546. The cooling water passage 545 will be described in detail later.

Further, the boss forming member 543 is provided with a disk 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 tubular shape. For example, as shown in FIG. 51, the boss forming member 543 is the 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, inside the vehicle) of the rotating shaft 501 facing the first end. It is fixed to. In the wheels 400 shown in FIGS. 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 has a configuration having a double peripheral wall in the radial direction about 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. 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 WA2".

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 circumferential 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 tightening, or the like. In this embodiment, the inverter housing 531 corresponds to the "housing member" and the electric module 532 corresponds to the "electric component".

A bearing 560 is housed inside the inner peripheral wall WA2 (boss portion 548), and the rotating 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 where it overlaps the rotor 510, the stator 520, and the inverter unit 530 in the axial direction. In the rotary electric machine 500 of the present embodiment, the magnet unit 512 can be made thinner in accordance with the orientation of the rotor 510, and the stator 520 adopts a slotless structure or a flat lead wire structure. It is possible to expand the hollow space inside the magnetic circuit portion in the radial direction by reducing the thickness dimension in the radial direction. This makes it possible to arrange the magnetic circuit unit, the inverter unit 530, and the bearing 560 in a state of being stacked in the radial direction. The boss portion 548 is a bearing holding portion that holds the bearing 560 inside the boss portion 548.

The bearing 560 is, for example, a radial ball bearing, and includes 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, and the inner ring 561 and the outer ring. It has a plurality of balls 563 arranged between 562. The bearing 560 is fixed to the inverter housing 531 by assembling the outer ring 562 to 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 ball 563 are all made of a metal material such as carbon steel.

Further, the inner ring 561 of the bearing 560 has a tubular portion 561a for accommodating the rotating shaft 501 and a flange 561b extending in an axially intersecting (orthogonal) direction from one end in the axial direction of the tubular portion 561a. .. 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 between the flange 502 of the rotating shaft 501 and the flange 561b of the inner ring 561 in a state where 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 respect to the axial direction (both are right angles in the present embodiment), and are sandwiched between the flanges 502 and 561b. The rotor carrier 511 is held in this state.

According to the configuration in which the rotor carrier 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 rotating shaft 501 can be maintained at an appropriate angle, and the parallelism of the magnet unit 512 with respect to the rotating shaft 501 is improved. Can be kept. As a result, resistance to vibration and the like can be increased even in a configuration in which the rotor carrier 511 is expanded in the radial direction.

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

The plurality of electric modules 532 are obtained by dividing electric components such as semiconductor switching elements and smoothing capacitors constituting a power converter into a plurality of individual modules, and the electric module 532 is a power element. 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 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, the mounting surface of the electric module 532 is a flat surface, so that 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 a flat surface.

It should be noted 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 wall is made by flattening the inner peripheral surface of the inner wall member 542 or by making the mounting surface of the electric module 532 curved. It is also possible to attach the electric module 532 directly to the member 542. It is also possible to fix the electric module 532 to the inverter housing 531 in a state of non-contact 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. It is also possible to fix the switch module 532A to the inner peripheral surface of the inner wall member 542 in a contact state, and to fix the capacitor module 532B 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 formed with a cooling water passage 545 through which cooling water as a refrigerant flows, so that each electric module 532 is cooled by the cooling water flowing through the cooling water passage 545. It has become. It is also possible to use cooling oil as the refrigerant instead of the cooling water. 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 in an annular shape so as to overlap each of the electric modules 532 in the radial direction and to surround each of the electric modules 532.

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

FIG. 58 shows a state of arrangement of each electric module 532 in the inverter housing 531. Note that FIG. 58 is the same vertical cross-sectional view as that of FIG. 50.

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

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

In the configuration shown in FIG. 58, the electric modules 532 arranged at 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. The 532s 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 channel port 574 in which the passage ends of the inlet passage 571 and the outlet passage 57 2 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 comprises a cooling water pipe. A pump 576 and a heat radiating device 575 are provided in the circulation path 575, and the cooling water circulates through the cooling water passage 545 and the circulation path 575 as the pump 576 is driven. The pump 576 is an electric pump. The heat radiating device 577 is, for example, a radiator that releases the heat of the cooling water to the atmosphere.

As shown in FIG. 50, since the stator 520 is arranged on the outside of the outer peripheral wall WA1 and the electric module 532 is arranged on the inner side, the stator 520 is arranged from the outside of the outer peripheral wall WA1. As the 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 parts 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 an inverter 600 is connected to the stator winding 521. The inverter 600 is composed of 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, 602 is turned on and off by the drive circuit 603, and the windings of each phase are energized by the on / off. Each switch 601, 602 is composed of a semiconductor switching element such as a MOSFET or an IGBT. Further, the upper and lower arms of each phase are connected in parallel with the series connection of the switches 601, 602 to a charge supply capacitor 604 for supplying the charges required for switching to the switches 601, 602.

The control device 607 includes a microcomputer composed of a CPU and various memories, and performs energization control by turning on / off each switch 601 and 602 based on various detection information in the rotary electric machine 500 and a request for power running drive and power generation. .. The control device 607 performs on / off control of each switch 601 and 602 by, for example, PWM control at a predetermined switching frequency (carrier frequency) and rectangular wave control. 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 electric time constant is small because the inductance of the stator 520 is reduced, and in a situation where the electric time constant is small, the switching frequency (carrier frequency). ) Is increased and the switching speed is increased. In this respect, since the charge supply capacitor 604 is connected in parallel to the series connection of the switches 601, 602 of each phase, the wiring inductance becomes low, and an appropriate surge even in a configuration in which the switching speed is increased. Countermeasures are possible.

The high potential side terminal of the inverter 600 is connected to the positive electrode terminal of the DC power supply 605, and the low potential side terminal is connected to the negative electrode terminal (ground) of the DC power supply 605. Further, a smoothing capacitor 606 is connected in parallel with the DC power supply 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), a drive circuit 603 (specifically, an electric element constituting the drive circuit 603), and a capacitor 604 for electric charge supply as heat generating components. Further, the capacitor module 532B has a smoothing capacitor 606 as a heat generating component. A specific configuration example of the switch module 532A is shown in FIG.

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

The module case 611 is made of an insulating material such as resin, and is fixed to the outer peripheral wall WA1 with its side surface in contact with 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 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.

When the switch module 532A is fixed to the outer peripheral wall WA1, the side closer to the outer peripheral wall WA1 in the switch module 532A, that is, the side closer to the cooling water passage 545 has higher cooling performance. Therefore, the switches 601 and 602 are cooled according to the cooling performance. , The order of arrangement of the drive circuit 603 and the capacitor 604 is defined. Specifically, when comparing the amount of heat generated, the order is from the largest to the switches 601, 602, the capacitor 604, and the drive circuit 603. Therefore, the switches are switched from the side closer to the outer peripheral wall WA1 according to the order of the amount of heat generated. These are arranged in the order of 601, 602, the capacitor 604, and the drive circuit 603. The contact surface of the switch module 532A is preferably smaller than the contactable surface on the inner peripheral surface of the inner wall member 542.

Although detailed illustration of the capacitor module 532B is omitted, the capacitor module 532B is configured such that the capacitor 606 is housed in a module case having the same shape and size as the switch module 532A. Similar to 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 on the radial inside of the outer peripheral wall WA1 of the inverter housing 531. For example, the switch module 532A may be arranged radially inside the capacitor module 532B, or vice versa.

When the rotary electric machine 500 is driven, heat exchange is performed between the switch module 532A and the condenser module 532B and the cooling water passage 545 via the inner wall member 542 of the outer peripheral wall WA1. As a result, the switch module 532A and the capacitor module 532B are cooled.

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

As shown in FIGS. 61A and 61B, the switch module 532A has a module case 611, one-phase switches 601, 602, a drive circuit 603, and a capacitor 604, as in FIG. 60. In addition, 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 piping portions 621 and 622 are the piping portion 621 on the inflow side for flowing the cooling water from the cooling water passage 545 of the outer peripheral wall WA1 to the cooler 623, and the cooling water from the cooler 623 to the cooling water passage 545. It is composed of a piping portion 622 on the outflow side that allows The cooler 623 is provided according to the object to be cooled, and a one-stage or a plurality of stages of the cooler 623 is used in the cooling device. In the configurations of FIGS. 61 (a) and 61 (b), two-stage coolers 623 are provided in a 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. Cooling water is supplied to each of these coolers 623 via units 621 and 622. The cooler 623 has, for example, a hollow inside. However, an inner fin 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 opposite outer peripheral wall side of the cooler 623 is a place where electrical parts to be cooled are arranged, and each of these places is (2), (1), (3) in order from the one with the highest cooling performance. There is. That is, the place sandwiched between the two coolers 623 has the highest cooling performance, and in the place adjacent to any one of the coolers 623, the place closer to the outer peripheral wall WA1 (cooling water passage 545) has higher cooling performance. ing. Taking this into consideration, in the configurations shown in FIGS. 61 (a) and 61 (b), switches 601, 602 are arranged between (2) first-stage and second-stage coolers 623, and the condenser 604 is (2). 1) The drive circuit 603 is arranged on the outer peripheral wall WA1 side of the first-stage cooler 623, and (3) the drive circuit 603 is arranged 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 either 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 wiring 612, respectively. Further, since the switches 601, 602 are located between the drive circuit 603 and the capacitor 604, the wiring 612 extending from the switches 601, 602 toward the drive circuit 603 and the wiring 612 extending from the switches 601, 602 toward the capacitor 604 Is a relationship that extends in opposite directions.

As shown in FIG. 61 (b), 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 portions 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 piping portion 622 located on the downstream side. In order to promote the inflow of the cooling water into the cooling device, the cooling water is provided in the cooling water passage 545 at a position between the inflow side piping portion 621 and the outflow side piping portion 621 when viewed in the circumferential direction. It is preferable that a regulation unit 624 is provided to regulate the flow of the water. The regulating portion 624 may be a blocking portion that shuts off the cooling water passage 545 or a throttle portion that reduces the passage area of the cooling water passage 545.

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

The configurations of FIGS. 62 (a) and 62 (b) differ from the configurations of FIGS. 61 (a) and 61 (b) described above in that the pair of piping portions 621 and 622 in the cooling device are arranged differently. The piping portions 621 and 622 of the above are arranged side by side in the axial direction. Further, as shown in FIG. 62C, in the cooling water passage 545, the passage portion communicating with the inflow side piping portion 621 and the passage portion communicating with the outflow side piping portion 622 are separated in the axial direction. Each of these passage portions is communicated with each other through each piping portion 621, 622 and each cooler 623.

In addition, the following configuration can be used 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 shown in FIG. 61 (a). In this case, the location with the highest cooling performance in the module case 611 is different from that in FIG. 61 (a), and the location on the outer peripheral wall WA1 side of the radial sides (both left and right sides in the figure) of the cooler 623 is the highest. The cooling performance is high, followed by the location on the opposite outer peripheral wall side of the cooler 623 and the location away from the cooler 623, in that order. Taking this into consideration, in the configuration shown in FIG. 63 (a), the switches 601, 602 are arranged at the locations on the outer peripheral wall WA1 side of the radial sides (left and right sides in the figure) of the cooler 623, and the condenser 604 is provided. , The drive circuit 603 is arranged at a place on the opposite outer peripheral wall side of the cooler 623, and is arranged at a place away from the cooler 623.

Further, 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 module case 611 may accommodate one of the switches 601, 602 for one phase, the drive circuit 603, and the capacitor 604.

In FIG. 63 (b), a pair of piping portions 621 and 622 and a two-stage cooler 623 are provided in the module case 611, and switches 601, 602 are installed in the first-stage and second-stage coolers 623. The capacitor 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. It is also possible to integrate the switches 601, 602 and the drive circuit 603 into a semiconductor module, and to accommodate the semiconductor module and the capacitor 604 in the module case 611.

In FIG. 63 (b), in the switch module 532A, a capacitor is arranged on the opposite side of the switch 601, 602 in at least one of the coolers 623 arranged on both sides of the switch 601, 602. It should be 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 a configuration in which the condenser 604 is arranged on both sides. It is possible.

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

Further, it is also possible to cool each electric module 532 by directly applying the 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, the 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 in the radial direction from the configuration shown in FIG. 58, and all of the electric module 532 is in the cooling water passage 545. It is conceivable to immerse it 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.

Further, 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 both of them are compared. In consideration of this point, it is possible to devise the arrangement of each electric module 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 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 in from the inlet passage 571 is first used for cooling the three switch modules 532A, and then used for cooling each capacitor module 532B. In FIG. 65, a 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 present invention is not limited to this and FIG. 61 (a) above. , (B), a pair of piping portions 621 and 622 may be arranged side by side in the circumferential direction.

Next, the configuration related to the electrical connection in each electric module 532 and the 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. 49. FIG. 68 is a perspective view showing the bus bar module 533 as a single unit. Here, the configurations related to the electrical connection of each electric module 532 and the bus bar module 533 will be described with reference to each of these figures.

As shown in FIG. 66, the inverter housing 531 is provided with a protrusion 573 provided on the inner wall member 542 (that is, a protrusion 573 provided with an inlet passage 571 and an outlet passage 57 2 leading to the cooling water passage 545) in the circumferential direction. Three switch modules 532A are arranged side by side in the circumferential direction at positions adjacent to the above, and six capacitor modules 532B are arranged side by side in the circumferential direction next to the three switch modules 532A. As an outline, in the inverter housing 531, the inside of the outer peripheral wall WA1 is equally divided into 10 regions (that is, the number of modules + 1) in the circumferential direction, and one electric module 532 is arranged in each of the nine regions. At the same time, a protrusion 573 is provided in the remaining one area. The three switch modules 532A are a U-phase module, a V-phase module, and a W-phase module.

As shown in FIG. 66 and the above-mentioned FIGS. 56 and 57, 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, the module terminal 615 is provided so as to extend from the module case 611 toward the back side (outside the vehicle) of the rotor carrier 511 (FIG. 51). reference).

The module terminals 615 of each electric module 532 are 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 forming an annular shape and the annular portion 631 to enable connection with an external device such as a power supply device or an ECU (electronic control unit). 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 in the inverter housing 531 at a position on the inner side in the radial direction of the outer peripheral wall WA1 and on one side in the axial direction of each electric module 532. The annular portion 631 has an annular main body portion formed of, for example, an insulating member such as a resin, and a plurality of bus bars embedded therein. 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 connected to the power supply device, and one signal terminal 632C connected to the external ECU. Each of these external connection terminals 632 (632A to 632C) is provided so as to be arranged in a row in the circumferential direction and to extend in the radial direction inside the annular portion 631 in the radial direction. As shown in FIG. 51, when the bus bar module 533 is assembled to the inverter housing 531 together with each electric module 532, one end of the external connection terminal 632 is configured to protrude from the end plate 547 of the boss forming member 543. .. Specifically, as shown in FIGS. 56 and 57, the end plate 547 of the boss forming member 543 is provided with an insertion hole 547a, and a cylindrical grommet 635 is attached to the insertion hole 547a, and the grommet is attached. The external connection terminal 632 is provided with the 635 inserted. The grommet 635 also functions as a sealed connector.

The winding connection terminal 633 is a terminal connected to the winding end 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 terminal 633 is a winding connection terminal 633U connected to the end of the U-phase winding in the stator winding 521, a winding connection terminal 633V connected to the end of the V-phase winding, and a W-phase winding. Each end of the wire has a winding connection terminal 633W connected to the connection. It is preferable that each of these winding connection terminals 633 and a current sensor 634 for detecting the current (U-phase current, V-phase current, W-phase current) flowing through each phase winding are 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 developed in a plane and schematically showing an electrical connection state between each electric module 532 and a bus bar module 533. FIG. 70 is a diagram schematically showing the connection between each electric module 532 and the bus bar module 533 in a state where each electric module 532 is arranged in an annular shape. In FIG. 69, the path for power transmission is shown by a solid line, and the path of the signal transmission system is shown by a dashed line. FIG. 70 shows only the path for power transmission.

The bus bar module 533 has a first bus bar 641, a second bus bar 642, and a third bus bar 643 as bus bars 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, 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 parts that easily generate heat due to the operation of the rotary 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 or the third bus bar 643 may be bent into a crank shape to bring the winding connection terminal 633 or 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 at the winding connection terminal 633 and the third bus bar 643 can be dissipated to the cooling water in the cooling water passage 545.

In FIG. 70, the first bus bar 641 and the second bus bar 642 are shown as bus bars having a ring shape, but each of these bus bars 641 and 642 does not necessarily have to be connected in a ring shape and is one in the circumferential direction. It may have a substantially C-shape with a broken portion. 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, actually) does not go 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 including a positive electrode side terminal, a negative electrode side terminal, a winding terminal, and a signal terminal. Of these, 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 bus bar of the signal transmission system. 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, each switch 601, 602 in each switch module 532A is turned on and off by a control signal input via the signal terminal 632C. Therefore, each switch module 532A is connected to the signal terminal 632C without going through the control device built in the rotary electric machine on the way. However, it is also possible to change this configuration so that the rotary electric machine has a built-in control device and the control signal from the control device is input to each switch module 532A. Such a configuration is shown in FIG.

In the configuration of FIG. 71, the control board 651 on which the control device 652 is mounted is provided, 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 related to power running or power generation from, for example, an external ECU which is a higher-level control device, and appropriately turns on / off the switches 601, 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 outside of the vehicle (inside the rotor carrier 511) of 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 so that at least a part thereof overlaps with each electric module 532 in the axial direction.

Further, each capacitor module 532B has two module terminals 615 composed 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, a protruding portion 573 having an inlet passage 571 and an outlet passage 572 for cooling water is provided in the inverter housing 531 at a position aligned with each electric module 532 in the circumferential direction, and the protrusion 573 thereof is provided. 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 inside the protruding portion 573 in the radial direction. Further, when viewed from the inside of the vehicle of the inverter housing 531, the end plate 547 of the boss forming member 543 is provided with the water channel port 574 and the external connection terminal 632 arranged in the radial direction (see FIG. 48).

In this case, by arranging the protrusion 573 and the external connection terminal 632 side by side in the circumferential direction together with the plurality of electric modules 532, the inverter unit 530 can be downsized, and the rotary electric machine 500 can be downsized.

Looking at FIGS. 45 and 47 showing the structure of the wheel 400, the cooling pipe H2 is connected to the water channel port 574, and the electrical wiring H1 is connected to the external connection terminal 632. In that state, the electrical wiring H1 and cooling are performed. The pipe H2 is housed in the storage duct 440.

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

If each switch module 532A is arranged at a position farthest from the external connection terminal 632, that is, a position opposite to the rotation shaft 501, the mutual inductance between the external connection terminal 632 and each switch module 532A. It is possible to suppress malfunctions caused by the above.

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 for detecting the electric angle θ of the rotary electric machine 500. The resolver 660 is an electromagnetic induction type sensor, and includes a resolver rotor 661 fixed to a rotating shaft 501 and a resolver stator 662 arranged so as to face each other on the radial outer side of the resolver rotor 661. The resolver rotor 661 has a disk ring shape, and is provided coaxially with the rotating shaft 501 in a state where the rotating shaft 501 is inserted. 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 excitation coil and a two-phase output coil.

The exciting coil of the stator coil 664 is excited by a sinusoidal exciting signal, and the magnetic flux generated in the exciting coil by the exciting signal interlinks the pair of output coils. At this time, since the relative arrangement relationship between the exciting coil and the pair of output coils changes periodically 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 interlocked. The number of magnetic fluxes to be applied changes periodically. In the present embodiment, the pair of output coils and the exciting coil are arranged so that the phases of the voltages generated in the pair of output coils are shifted by π / 2 from each other. As a result, the output voltage of each of the pair of output coils becomes a modulated wave in which the excitation signal is modulated by each of the modulated waves sinθ and cosθ. 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 electric angle θ by the detection based on the generated modulated wave and the 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 an external device via the signal terminal 632C. When the rotary 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 constituting the inverter housing 531 has a hollow tubular shape, and the inner peripheral side of the boss portion 548 is oriented orthogonal to the axial direction. A protruding portion 548a extending to the surface is formed. Then, the resolver stator 662 is fixed by a screw or the like in a state of being in contact with the protruding portion 548a in the axial direction. In the boss portion 548, a bearing 560 is provided on one side in the axial direction with the protrusion 548a interposed therebetween, and a resolver 660 is coaxially provided on the other side.

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

The space in which the resolver 660 is housed is a space surrounded by a boss portion 548 forming an annular shape in the boss forming member 543 and sandwiched between the bearing 560 and the housing cover 666 in the axial direction, and the circumference of the resolver 660 is conductive. Surrounded by material. This makes it possible to suppress the influence of electromagnetic noise on the resolver 660.

Further, as described above, the inverter housing 531 has a double outer peripheral wall WA1 and an inner peripheral wall WA2 (see FIG. 57), and is located outside the double peripheral wall (outside the outer peripheral wall WA1). The stator 520 is arranged, the electric module 532 is arranged between the double peripheral walls (between WA1 and WA2), and the resolver 660 is arranged inside the double peripheral wall (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 from each other by a conductive partition wall (particularly a double conductive partition wall in the present embodiment) and are fixed. The occurrence of mutual magnetic interference between the child 520 side (magnetic circuit side) and the resolver 660 can be suitably suppressed.

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 disk ring-shaped rotor cover 670 is attached to the open end. The rotor cover 670 may be fixed to the rotor carrier 511 by any joining method such as welding, adhesion, or screwing. It is more preferable that the rotor cover 670 has a portion whose size is set 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 on the radial outer side of the inverter housing 531. At the joint where the stator 520 and the inverter housing 531 are joined to each other, the inverter housing 531 is shafted with respect to the stator 520. It protrudes 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 sealing material 671 is provided between the inner peripheral surface of the rotor cover 670 and the outer peripheral surface of the inverter housing 531 to seal the gap between them. The accommodating space of the magnet unit 512 and the stator 520 is sealed by the sealing material 671. The sealing material 671 may be, for example, a sliding seal made of a resin material.

According to the present 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 was arranged inside the magnetic circuit portion including the magnet unit 512 and the stator winding 521 in the radial direction, and the cooling water passage 545 was formed on the outer peripheral wall WA1. Further, a plurality of electric modules 532 are arranged in the radial direction of the outer peripheral wall WA1 along the outer peripheral wall WA1 in the circumferential direction. As a result, the magnetic circuit unit, the cooling water passage 545, and the power converter can be arranged so as to be stacked in the radial direction of the rotary electric machine 500, and efficient component arrangement is possible while reducing the dimensions in the axial direction. It becomes. Further, the plurality of electric modules 532 constituting the power converter can be efficiently cooled. As a result, the rotary electric machine 500 can be realized with high efficiency and miniaturization.

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

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

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

For example, in the switch module 532A, cooling water is allowed to flow into the module from the cooling water passage 545, and the semiconductor switching element or the like is cooled by the cooling water. In this case, the switch module 532A is cooled by heat exchange by the cooling water inside the module in addition to heat exchange by the cooling water on the outer peripheral wall WA1. As a result, the cooling effect of the switch module 532A can be enhanced.

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 placed on the switch module 532A. The configuration is such that it is located on the downstream side. In this case, assuming that the cooling water flowing through the cooling water passage 545 is lower in temperature toward the upstream side, it is possible to realize a configuration in which the switch module 532A is preferentially cooled.

The distance between the electric modules adjacent to each other in the circumferential direction is partially widened, and a protruding portion 573 having an inlet passage 571 and an outlet passage 57 2 is provided in a portion of the widened gap (second interval INT2). As a result, the inlet passage 571 and the outlet passage 572 of the cooling water passage 545 can be suitably formed in the portion on the outer peripheral wall WA1 in the radial direction. That is, in order to improve the cooling performance, it is necessary to secure the flow amount of the refrigerant, and for that purpose, it is conceivable to increase the opening areas of the inlet passage 571 and the outlet passage 572. In this regard, as described above, by partially widening the distance between the electric modules and providing the protruding portion 573, the inlet passage 571 and the outlet passage 572 having a desired size can be suitably formed.

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

In the outer rotor type rotary electric machine 500, the stator 520 is fixed on the radial outer side of the outer peripheral wall WA1, and a plurality of electric modules 532 are arranged on the radial inner side. As a result, the heat of the stator 520 is transferred to the outer peripheral wall WA1 from the radial outer side, and the heat of the electric module 532 is transferred from the radial inner side. 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 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 are electrically connected by the winding connection terminal 633 of the bus bar module 533 with the outer peripheral wall WA1 interposed therebetween. 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 formed in an annular shape on the outer peripheral wall WA1, that is, the inside and outside of the outer peripheral wall WA1 are separated by the cooling water passage 545, the electric module 532 and the stator winding 521 Can be suitably connected to.

In the rotary electric machine 500 of the present embodiment, by reducing or eliminating the teeth (iron cores) between the conductors 523 arranged in the circumferential direction in the stator 520, the torque is limited due to the magnetic saturation generated between the conductors 523. In addition to suppressing the torque decrease, the lead wire 523 is made flat and thin. In this case, even if the outer diameter of the rotary electric machine 500 is the same, the area inside the magnetic circuit portion in the radial direction can be expanded by reducing the thickness of the stator 520, and the inner area is used for cooling. The outer peripheral wall WA1 having the water passage 545 and a plurality of electric modules 532 provided radially inside the outer peripheral wall WA1 can be preferably arranged.

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

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

The wheel 400 using the rotary 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 rotary electric machine 500 has been miniaturized, it is possible to save space even if it is assumed to be assembled to the vehicle body. Therefore, it is possible to realize an advantageous configuration in expanding the installation area of the power supply device such as a battery in the vehicle and expanding the vehicle interior space.

A modified example of the in-wheel motor will be described below.

(Modification example 1 in an in-wheel motor)
In the rotary electric machine 500, the electric module 532 and the bus bar module 533 are arranged on the radial inside of the outer peripheral wall WA1 of the inverter unit 530, and the electric module 532 and the bus bar are arranged on the inner and outer sides of 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 arbitrarily set. 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, the winding connection line (for example, winding connection terminal 633) used for the connection is connected. The guide position can be set arbitrarily.

That is, the position of the bus bar module 533 with respect to the electric module 532 is
(Α1) A configuration in which the bus bar module 533 is located outside the vehicle in the axial direction from the electric module 532, that is, behind the rotor carrier 511.
(Α2) The bus bar module 533 is located inside the vehicle in the axial direction from the electric module 532, that is, on the front side of the rotor carrier 511 side.
Can be considered.

Also, as a position to guide the winding connection line,
(Β1) A configuration in which the winding connection wire is guided in the axial direction on the outside of the vehicle, that is, on the back side of the rotor carrier 511.
(Β2) A configuration in which the winding connection 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.

Hereinafter, four configuration examples relating to the arrangement of the electric module 532, the bus bar module 533, and the winding connection line 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 same reference numerals are given to the configurations already described. The winding connection line 637 is an electric wiring that connects each phase winding of the stator winding 521 and the bus bar module 533, and for example, the winding connection terminal 633 described above corresponds to this.

In the configuration of FIG. 72 (a), the above (α1) 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 connection line 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 on the outside of the vehicle (the back side of the rotor carrier 511). This corresponds to the configuration shown in FIG. 49.

According to this configuration, the cooling water passage 545 can be provided on the outer peripheral wall WA1 without fear of interference with the winding connection line 637. Further, the winding connection line 637 that connects 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 line 637. That is, the electric module 532 and the bus bar module 533 are connected on the outside of the vehicle (the back side of the rotor carrier 511), and the stator winding 521 and the bus bar module 533 are connected on the inside of 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 on the outer peripheral wall WA1 without fear of interference with the winding connection line 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 connection line 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 connected 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 line 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 (on the 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 (in front of the rotor carrier 511) to temporarily add an electric component such as a fan motor. 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 inside the vehicle than the bearing, and it is considered that wiring to the resolver 660 becomes easier.

(Modification example 2 in an 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 with respect to the rotating body will be described below.

FIGS. 73 (a) to 73 (c) are block diagrams showing an example of a mounting structure of the resolver rotor 661 to the rotating body. In any of the configurations, the resolver 660 is provided in a closed space surrounded by a rotor carrier 511, an inverter housing 531 and the like, and protected from external water and mud. Of FIGS. 73 (a) to 73 (c), in FIG. 73 (a), the bearing 560 has the same configuration as that in FIG. 49. Further, in FIGS. 73B and 73C, the bearing 560 has a configuration different from that in FIG. 49, and is arranged at a position away from the end plate 514 of the rotor carrier 511. In each of these figures, two locations are illustrated as mounting locations for the resolver rotor 661. Although the resolver stator 662 is not shown, 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 its vicinity, and the resolver stator 662 may be fixed to the boss portion 548. ..

In the configuration of FIG. 73A, the 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 is provided on the axial end surface of the tubular portion 561a of the inner ring 561.

In the configuration of FIG. 73B, 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 in the rotor carrier 511. Alternatively, in a configuration in which the rotor carrier 511 has a tubular portion 515 extending from the inner peripheral edge portion of the end plate 514 along the rotation shaft 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), the resolver rotor 661 is attached to the rotating shaft 501. Specifically, the resolver rotor 661 is provided between the end plate 514 of the rotor carrier 511 and the bearing 560 on the rotating shaft 501, or is opposite to the rotor carrier 511 with the bearing 560 sandwiched on the rotating shaft 501. It is located on the side.

(Modification example 3 in an in-wheel motor)
A modification of the inverter housing 531 and the rotor cover 670 will be described below with reference to FIG. 74. 74 (a) and 74 (b) are vertical cross-sectional views showing a simplified configuration of the rotary electric machine 500, and 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 in which a part of the configuration of FIG. 74 (a) is modified. Corresponds to.

In the configuration shown in FIG. 74A, 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 end surface on the inner diameter side of the rotor cover 670 faces the outer peripheral surface of the outer peripheral wall WA1, and a sealing material 671 is provided between them. A housing cover 666 is attached to the hollow portion of the boss portion 548 of the inverter housing 531, and a sealing material 667 is provided between the housing cover 666 and the rotating shaft 501. The external connection terminal 632 constituting the bus bar module 533 penetrates the inverter housing 531 and extends to the inside of the vehicle (lower side in the figure).

Further, the inverter housing 531 is formed with an inlet passage 571 and an outlet passage 572 communicating with the cooling water passage 545, and a water channel port 574 including the passage ends of the inlet passage 571 and the outlet passage 57 2 is formed. ..

On the other hand, in the configuration shown in FIG. 74 (b), the inverter housing 531 (specifically, the boss forming member 543) is formed with an annular convex portion 681 extending toward the protruding side (inside the vehicle) of the rotating shaft 501. , The rotor cover 670 is provided so as to surround the convex portion 681 of the inverter housing 531. That is, 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 sealing material 671 is provided between them. Further, the external connection terminal 632 constituting the bus bar module 533 penetrates the boss portion 548 of the inverter housing 531 and extends into the hollow region of the boss portion 548, and also penetrates the housing cover 666 and penetrates the inside of the vehicle (lower side of the figure). Extends to.

Further, the inverter housing 531 is formed with an inlet passage 571 and an outlet passage 572 communicating with the cooling water passage 545, and the inlet passage 571 and the outlet passage 572 extend into the hollow region of the boss portion 548 and are relay pipes. It extends to the inside of the vehicle (lower side of the figure) from the housing cover 666 via 682. In this configuration, the piping portion extending from the housing cover 666 to the inside of the vehicle is 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 inserted into the inverter while maintaining the airtightness of the internal space of the rotor carrier 511 and the rotor cover 670. 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 provided twice in the axial direction at a position inside the vehicle from the electric module 532, and the inconvenience caused by electromagnetic noise, which is a concern in the electric module 532, is suppressed. can do. Further, by reducing the inner diameter of the rotor cover 670, the sliding diameter of the sealing material 671 can be reduced, and mechanical loss in the rotating sliding portion can be suppressed.

(Modification example 4 in an in-wheel motor)
A modified example of the stator winding 521 will be described below. FIG. 75 shows a modified example of the stator winding 521.

As shown in FIG. 75, the stator winding 521 uses a wire rod having a rectangular cross section, and is wound by a wave winding with the long side of the wire rod extending in the circumferential direction. In this case, the lead wires 523 of each phase on the coil side of the stator winding 521 are arranged at predetermined pitch intervals for each phase and are connected to each other at the coil ends. The conductive wires 523 adjacent to each other in the circumferential direction on the coil side are in contact with each other at the end faces in the circumferential direction, or are arranged close to each other with a minute interval.

Further, in the stator winding 521, the wire rod is bent in the radial direction for each phase at the coil end. More specifically, the stator winding 521 (lead wire material) 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 phase windings are formed. Interference with each other is avoided. In the illustrated configuration, the wire rods are bent at right angles inward in the radial direction for each phase, with each phase winding being different by the thickness of the wire rod. In each lead wire 523 arranged in the circumferential direction, the length dimension between both ends in the axial direction may be the same for each lead wire 523.

When the stator core 522 is assembled to the stator winding 521 to manufacture the stator 520, a part of the annular shape of the stator winding 521 is disconnected as a non-connection (that is, the stator winding). 521 may be substantially C-shaped), and after assembling the stator core 522 on the inner peripheral side of the stator winding 521, the disconnecting portions may be connected to each other to form the stator winding 521 in an annular shape.

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

(Other variants)
-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 provided together in one place, but this configuration is changed to change the configuration so that the inlet passage 571 and the outlet The passages 572 and the passages 572 may be provided at different positions in the circumferential direction. For example, the inlet passage 571 and the exit passage 57 2 may be provided at positions different from each other by 180 degrees in the circumferential direction, or at least one of the inlet passage 571 and the exit passage 572 may be provided.

The wheel 400 of the above embodiment has a configuration in which the rotary shaft 501 protrudes on one side in the axial direction of the rotary electric machine 500, but this may be changed to a configuration in which the rotary shaft 501 protrudes 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 is one wheel.

-It is also possible to use an inner rotor type rotary electric machine as the rotary electric machine 500 used for the wheel 400.

(Modification 5 in in-wheel motor)
In the rotary electric machine 500, the bearing 560 that supports the rotary shaft 501 may be changed as shown in FIG. 76. The details will be described below.

As shown in FIG. 76, the rotary electric machine 500 includes a first bearing 1001 that rotatably supports the rotary shaft 501 and a second bearing 1002.

The first bearing 1001 and the second bearing 1002 are provided so that their positions are different from each other in the axial direction. The first bearing 1001 is provided inside the vehicle in the axial direction, and the second bearing 1002 is provided outside the vehicle.

The first bearing 1001 and the second bearing 1002 are, for example, radial ball bearings, respectively, like the bearing 560 described above, and have a tubular inner ring 1011, 1012 and a cylinder having a diameter larger than the inner ring 1011, 1012, respectively. It has an outer ring 1021, 1022 arranged on the outer side in the radial direction of the inner ring 1011, 1012, and a plurality of rolling elements 1031, 1032 (balls) arranged between the inner ring 1011, 1012 and the outer ring 1021, 1022. are doing.

The inner rings 1011, 1012 are fixed to the rotating shaft 501. On the other hand, the outer rings 1021 and 1022 are fixed to the inner peripheral surface of the cylindrical bearing holding portion 1050. The bearing holding portion 1050 is fixed to the inner peripheral surface of the boss portion 548, and is arranged around the rotating shaft 501 so as to surround the outer periphery of the rotating shaft 501. The bearing holding portion 1050 is arranged apart from the electric module 532 in the radial direction. That is, the electric module 532 is arranged so as to surround the bearing holding portion 1050 with a constant interval (space) in the radial direction centered on the bearing holding portion 1050.

Further, the inner ring 1012 of the second bearing 1002 has a tubular portion 1012a accommodating the rotating shaft 501 and the axial direction of the tubular portion 1012a, similarly to the inner ring 561 of the bearing 560 described above in the embodiment as the vehicle in-wheel motor. It has a flange 1012b extending from one end in a direction intersecting (orthogonal) in the axial direction. The flange 1012b is a portion that comes into contact with the end plate 514 of the rotor carrier 511 from the inside, and in a state where the second bearing 1002 is assembled to the rotating shaft 501, the flange 502 of the rotating shaft 501 and the flange 1012b of the inner ring 1012 are used. The rotor carrier 511 is held in a sandwiched state.

Further, in order to urge braking torque to one end of the rotating shaft 501 (one end inside the vehicle) as a braking device, the disc rotor 431 is fixed to the rotating shaft 501 of the rotating electric machine 500 and rotates integrally.

By the way, in this modification, the center of gravity G100 of the rotor 510 is located on the second end side (inside the vehicle) of the cylindrical portion 513 of the rotor carrier 511 in the axial direction as shown in FIG. 76. ) It is close. In the modified example shown in FIG. 76, the center of gravity G100 of the rotor 510 is calculated in consideration of the disc rotor 431, the rotor carrier 511, the magnet unit 512, and the rotating shaft 501. More specifically, the center of gravity G100 of the rotor 510 is calculated in consideration of the position of the center of gravity of the disc rotor 431, the position of the center of gravity of the rotor carrier 511, the position of the center of gravity of the magnet unit 512, and the position of the center of gravity of the rotating shaft 501. ing. The position of each center of gravity is calculated based on the weight and shape of each member.

In the rotary electric machine 500, when the rotary shaft 501 is pivotally supported by two bearings having different positions in the axial direction, the shaft shake becomes large in the bearing farther from the center of gravity G100 of the rotor 510, and vibration and fluttering are likely to occur. In the modified example shown in FIG. 76, vibration and fluttering are more likely to occur in the second bearing 1002 as compared with the first bearing 1001. That is, the farther the rotor 510 is from the center of gravity G100, a larger load (centrifugal force, etc.) is applied to the bearing, so that vibration and fluttering are likely to occur.

Therefore, in this modification (FIG. 76), the second bearing 1002 is provided so that its outer diameter is larger than that of the first bearing 1001. More specifically, the outer ring 1022 of the second bearing 1002 is configured to have a larger outer diameter than the outer ring 1021 of the first bearing 1001. Further, the inner ring 1012 of the second bearing 1002 is configured to have a larger inner diameter than the inner ring 1011 of the first bearing 1001.

As a result, the number of rolling elements 1032 of the second bearing 1002 becomes larger than the number of rolling elements 1031 of the first bearing 1001. That is, the second bearing 1002 has more points (or contact areas) for supporting the load than the first bearing 1001, and is easy to support even if a larger load is received. Therefore, the second bearing 1002 can suitably receive the load, suppress the shaft shake, and preferably suppress the vibration and fluttering.

As the outer diameter of the second bearing 1002 increases, the bearing holding portion 1050 is also configured so that the inner diameter differs in the axial direction as shown in FIG. 76. That is, the bearing holding portion 1050 has a tapered surface 1051 so as to increase the diameter in the axial direction from the inside to the outside of the vehicle.

Further, the linear expansion coefficient (thermal expansion coefficient) of the bearing holding portion 1050 is set to be about the same as the linear expansion coefficient (thermal expansion coefficient) of the first bearing 1001 and the second bearing 1002. More specifically, the coefficient of linear expansion of the bearing holding portion 1050 is the same as the coefficient of linear expansion of the outer rings 1021 and 1022 of the first bearing 1001 and the second bearing 1002.

This modification (Fig. 76) has the following effects.

The second bearing 1002 is fixed far from the center of gravity G100 of the rotor 510, and a large axial shake is likely to occur due to centrifugal force. Therefore, the outer diameter of the second bearing 1002 is made larger than that of the first bearing 1001. As a result, the contact area of the rolling element 1032 of the second bearing 1002 becomes large, or the number of rolling elements 1032 increases, and the number of support points increases. Therefore, as compared with the first bearing 1001, the second bearing 1002 can preferably disperse and receive the load, suppress shaft shake, and preferably suppress vibration and fluttering.

Further, the coefficient of linear expansion of the bearing holding portion 1050 and the coefficient of linear expansion of the outer ring 1022 of the second bearing 1002 were made the same. As a result, even if the temperature changes due to heat generation or the like, the outer ring 1022 of the bearing holding portion 1050 and the second bearing 1002 expands to the same extent, so that the bearing holding portion 1050 and the second bearing 1002 loosen or loosen. It is possible to suppress the occurrence of sticking.

The bearing holding portion 1050 and the electric module 532 were separated from each other. Therefore, it is possible to prevent the bearings 1001 and 1002 and the heating elements called the electric module 532 from coming into contact with each other. Further, the cooling performance is improved by passing running wind or the like between the bearing holding portion 1050 and the electric module 532. Further, by arranging the bearings 1001 and 1002 inside the electric module 532 in the radial direction, the shaft length of the rotary electric machine 500 can be suppressed, and it becomes easy to adopt as an in-wheel motor.

(Modification example 6 in in-wheel motor)
In the rotary electric machine 500, the bearing 560 that supports the rotary shaft 501 may be changed as shown in FIG. 77. The details will be described below.

As shown in FIG. 77, the rotary electric machine 500 includes a first bearing 2001 that rotatably supports the rotary shaft 501 and a second bearing 2002.

The first bearing 2001 and the second bearing 2002 are provided so that their positions are different from each other in the axial direction. The second bearing 2002 is provided inside the vehicle in the axial direction, and the first bearing 2001 is provided outside the vehicle.

The first bearing 2001 and the second bearing 2002 are, for example, radial ball bearings, respectively, like the bearing 560 described above, and have a larger diameter than the inner ring 2011,1022 and the inner ring 2011,202, respectively, and have an inner ring. It has a tubular outer ring 2021, 2022 arranged on the outer side in the radial direction of 2012,1022, and a plurality of rolling elements 2031, 2032 (balls) arranged between the inner ring 2011, 2022 and the outer ring 2021, 2022. ing.

The inner ring 2011, 1012 is fixed to the rotating shaft 501. On the other hand, the outer rings 2021 and 2022 are fixed to the inner peripheral surface of the cylindrical bearing holding portion 2050. The bearing holding portion 2050 is fixed to the inner peripheral surface of the boss portion 548, and is arranged around the rotating shaft 501 so as to surround the outer periphery of the rotating shaft 501. Further, the inner ring 2011 of the first bearing 2001 is oriented in the direction orthogonal to the axial direction from the tubular portion 2011a accommodating the rotating shaft 501 and the axial end portion of the tubular portion 2011a, similarly to the inner ring 561 of the bearing 560 described above. It has an extending flange 2011b.

By the way, in this modification (FIG. 77), the center of gravity G200 of the rotor 510 is located on the first end side (outside the vehicle) of the cylindrical portion 513 of the rotor carrier 511 rather than the second end side (inside the vehicle) in the axial direction. It has become. In this modification (FIG. 77), the center of gravity G200 of the rotor 510 is calculated in consideration of the rotor carrier 511, the magnet unit 512, and the rotating shaft 501. More specifically, the position of the center of gravity G200 of the rotor 510 is calculated in consideration of the position of the center of gravity of the rotor carrier 511, the position of the center of gravity of the magnet unit 512, and the position of the center of gravity of the rotating shaft 501.

Therefore, in this modified example, as shown in FIG. 77, the second bearing 2002 is provided so that its outer diameter is larger than that of the first bearing 2001. More specifically, the outer ring 2022 of the second bearing 2002 is configured to have a larger outer diameter than the outer ring 2021 of the first bearing 2001. On the other hand, the inner ring 2012 of the second bearing 2002 is configured to have a smaller inner diameter than the inner ring 2011 of the first bearing 2001.

As a result, the number of rolling elements 2032 of the second bearing 2002 will be larger than the number of rolling elements 2032 of the first bearing 2001. That is, the second bearing 2002 has more points (or contact areas) for supporting the load than the first bearing 2001, and is easy to support even if a larger load is received. Therefore, the second bearing 2002 can appropriately disperse and receive the load, suppress shaft shake, and preferably suppress vibration and fluttering.

As the outer diameter of the second bearing 2002 increases, the bearing holding portion 2050 is also configured so that the inner diameter differs in the axial direction as shown in FIG. 77.

Further, in this modification, a resolver 660 as a rotation angle sensor is arranged. As shown in FIG. 77, the resolver rotor 661, which is a rotating portion of the resolver 660, is fixed to the rotating shaft 501 and rotates integrally. Further, the resolver rotor 661 is arranged closer to the second bearing 2002 than the first bearing 2001 in the axial direction, and is arranged inside the vehicle in FIG. 77.

The resolver stator 662 of the resolver 660 is fixed to the bearing holding portion 2050 so as to face each other on the radial outer side of the resolver rotor 661. Since the configurations of the resolver 660 other than these are the same as those described above, the description thereof will be omitted here.

This modification has the following effects.

The second bearing 2002 is fixed far from the center of gravity G200 of the rotor 510, and a large axial shake is likely to occur due to centrifugal force. Therefore, the outer diameter of the second bearing 2002 is made larger than that of the first bearing 2001. As a result, the contact area of the rolling element 2032 of the second bearing 2002 becomes large. Alternatively, the number of rolling elements 2032 increases, and the number of support points increases. Therefore, as compared with the first bearing 2001, the second bearing 2002 can suitably disperse and receive the load, suppress shaft shake, and preferably suppress vibration and fluttering.

When assembling the rotary electric machine 500, for convenience of arranging various members from the open end side (inside the vehicle) of the rotor carrier 511, from the member on the side of the end plate 514 (outside the vehicle) which is the bottom of the rotor carrier 511. It is common to assemble in order. Therefore, the second bearing 2002 having a large diameter is arranged at a position distant from the end plate 514 which is the bottom of the rotor carrier 511 as compared with the first bearing 2001 in the axial direction, so that it is easy to assemble. That is, since the second bearing 2002 having a large diameter is assembled after the first bearing 2001 having a small diameter, it is easy to assemble.

Since the resolver 660 is arranged closer to the second bearing 2002 than the first bearing 2001 in the axial direction, the vibration of the rotating shaft 501 is suppressed by the second bearing 2002 for the reason described above, and the resolver 660 is detected. The accuracy can be improved.

(Another example of modification 5 and 6 of the in-wheel motor)
In the above modification, the linear expansion coefficients of the second bearings 1002 and 2002 and the linear expansion coefficients of the bearing holding portions 1050 and 2050 may be slightly different.

-In the above modification, the electric module 532 and the bearing holding portions 1050 and 2050 may be brought into contact with each other to transfer heat.

In the above modification, the bearing holding portion 2050 may be provided with a space for accommodating the resolver 660. Specifically, as in the protrusion 548a shown in FIG. 49, a protrusion extending in an axial direction is formed on the inner peripheral surface of the bearing holding portion 2050 so as to partition the bearings 2001 and 2002 and the resolver 660. It may be formed. Further, a disk ring-shaped housing cover 666 that closes the accommodating space of the resolver 660 may be provided. In this case, it is desirable that the bearing holding portion 2050 and the housing cover 666 are made of a conductive material. Thereby, the influence of electromagnetic noise can be prevented.

-In the above modification, the first bearing 1001, 2001 and the second bearing 1002, 2002 may be roller bearings. Further, a sliding bearing may be used. By adopting these, it is possible to increase the contact area on the sliding surface and further suppress vibration.

-In the above modification, the bearing holding portions 1050 and 2050 may be integrally formed by the boss portion 548.

Disclosures herein are not limited to the illustrated embodiments. The disclosure includes exemplary embodiments and modifications by those skilled in the art based on them. For example, disclosure is not limited to the parts and / or element combinations shown in the embodiments. Disclosure can be carried out in various combinations. Disclosures can have additional parts that can be added to the embodiments. The disclosure includes parts and / or elements of the embodiment omitted. Disclosures include the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some technical scopes disclosed are indicated by the statements of the claims and should be understood to include all modifications within the meaning and scope equivalent to the statements of the claims.

500 ... Rotating electric machine, 501 ... Rotating shaft, 510 ... Rotor, 520 ... Stator, 1001, 2001 ... First bearing, 1002, 2002 ... Second bearing, 1021, 2021 ... First bearing outer ring, 1022, 2022 ... Outer ring of the second bearing, G100, G200 ... Center of gravity.

Claims (7)

In a rotary electric machine (500) including a rotor (510) rotatably fixed around a rotation shaft (501) and a stator (520) arranged so as to face the rotor in the radial direction. ,
A first bearing (1001, 2001) that rotatably supports the rotating shaft of the rotor and a second bearing (1002, 2002) are provided.
The second bearing is arranged at a position axially distant from the center of gravity (G100, G200) of the rotor as compared with the first bearing, and at least the outer ring (1022, 2022) of the second bearing. ) Is larger than the outer diameter of the outer ring (1021, 2021) of the first bearing. The stator has a tubular bearing holding portion (1050, 2050), and the second bearing is fixed to the inner peripheral surface of the bearing holding portion.
The rotary electric machine according to claim 1, wherein the coefficient of linear expansion of the bearing holding portion and the coefficient of linear expansion of the second bearing are the same. The rotary electric machine includes an electric module (532).
The rotor has a tubular rotor carrier (511) and has a tubular rotor carrier (511).
The stator has a tubular bearing holding portion (1050, 2050), and the second bearing is fixed to the inner peripheral surface of the bearing holding portion.
The electric module is fixed to the stator in a state of being housed inside the rotor carrier.
According to claim 1 or 2, the first bearing and the second bearing are arranged radially inside the electric module, and the bearing holding portion is separated from the electric module in the radial direction. The rotating electric machine described. The rotor has a tubular rotor carrier (511) and has a tubular rotor carrier (511).
The stator is arranged inside the rotor carrier and
The rotating shaft is fixed to an end plate (514) provided on one end side in the axial direction of the rotor carrier.
The rotary electric machine according to any one of claims 1 to 3, wherein the second bearing is axially separated from the end plate as compared with the first bearing. A rotation angle sensor (660) for detecting the rotation angle of the rotation shaft is fixed to the rotation shaft.
The rotary electric machine according to claim 4, wherein the second bearing is arranged in the vicinity of the rotation angle sensor in the axial direction as compared with the first bearing. The rotor includes a rotor carrier and a magnet portion (512) fixed to the rotor carrier.
The rotating electric machine according to any one of claims 1 to 5, wherein the center of gravity of the rotor is calculated in consideration of at least the rotor carrier, the magnet portion, and the rotating shaft. A brake device for braking the rotation of the rotor is fixed to the rotary electric machine.
The rotary electric machine according to any one of claims 1 to 6, wherein the center of gravity of the rotor is calculated in consideration of the brake device fixed to the rotor.

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