Rotary electric machine

Abstract

A bus bar module (70) includes a bus bar holder (74) fixed to an axial end of a stator. A plurality of bus bars (71) and a plurality of relay terminals (73) provided for each phase of a stator winding are assembled to the bus bar holder. Each relay terminal has a first portion (101) that extends in the axial direction and has one end fixed to a circuit board, and a second portion (102) that is bent in the radial direction from the other end of the first portion. The first portion is provided with a stress absorption part (107) having a bent shape. The bus bar module includes a holding structure for holding the relay terminal by means of a terminal holder (75). The plurality of relay terminals are arranged side by side in the circumferential direction, and are collectively fixed to the bus bar holder in a state in which the second portion is sandwiched between the bus bar holder and the terminal holder.

Description

rotating electrical machines CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-150643 filed on September 2, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a rotating electric machine.

[0003] Conventionally, a rotating electric machine having a stator and a rotor has been known in which a control device is integrally provided on one axial end of the stator. Specifically, a bus bar is connected to each phase winding of the stator winding, and the bus bar is connected to a circuit board by a relay terminal extending in the axial direction for each phase. For example, Patent Document 1 discloses a known technique for providing a bus bar module (connection plate unit) on one axial end of the stator.

[0004] Patent No. 5320431

[0005] In the above-described configuration in which the bus bars provided for each phase of the stator winding are connected to the circuit board by relay terminals, the relay terminals are fixed to the bus bar module by welding, press-fitting, or the like. In this case, there is a concern that unnecessary stress may act on the relay terminals due to errors in the assembly of the components or vibrations generated by the rotating electric machine, which may result in damage to the relay terminals or disconnection of the relay terminals. Such problems may impair the functionality of the rotating electric machine.

[0006] Furthermore, in a busbar module, the relay terminals of each phase are individually fixed, and there is a concern that fixing each relay terminal without causing misalignment will require complicated work and increase the number of steps, and that misalignment of the relay terminals relative to each other will result in a decrease in yield.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a rotating electric machine that can improve the assembly ease of the relay terminal while effectively suppressing defects such as breakage of the relay terminal.

[0008] The rotating electric machine of the present disclosure comprises: a stator having stator windings of multiple phases; a rotor disposed radially opposite the stator and rotating together with a rotary shaft; a busbar module having an annular busbar holder fixed to an axial end of the stator, with multiple busbars and multiple relay terminals attached to the busbar holder, each busbar being provided for each phase of the stator winding; and a circuit board disposed on the opposite side of the stator in the axial direction with the busbar module sandwiched therebetween, wherein the busbars and the circuit board are electrically connected by the relay terminals, and each relay terminal is made of an elongated conductor and has a first portion extending axially and one end of which is fixed to the circuit board, and a second portion bent radially from the other end of the first portion, and the first portion is provided with a bent-shaped stress absorbing portion, and the busbar module has a holding structure that holds the relay terminals with a terminal holder, The relay terminals are arranged side by side in the circumferential direction and are collectively fixed to the busbar holder with the second portions sandwiched between the busbar holder and the terminal holder.

[0009] In a rotating electric machine in which a stator having a stator winding, a busbar module having busbars and relay terminals, and a circuit board are arranged side by side in the axial direction and the busbars and the circuit board are electrically connected by the relay terminals, there is a concern that if unnecessary stress acts on the relay terminals due to errors in the assembly of each component or vibrations generated by the rotating electric machine, problems such as damage to the relay terminals may occur. On the other hand, there is a concern that the work of properly assembling multiple relay terminals to a busbar holder may be complicated.

[0010] In this regard, each relay terminal made of a long conductor is configured to have a bent stress-absorbing portion at a first portion extending axially and having one end fixed to the circuit board. Therefore, even if unnecessary stress acts on the relay terminal between the busbar and the circuit board, the stress is alleviated by the bent shape of the stress-absorbing portion. Furthermore, multiple relay terminals are arranged circumferentially, and their second portions, bent radially from the first portion, are sandwiched between the busbar holder and the terminal holder, and are then collectively fixed to the busbar holder. This allows multiple relay terminals to be integrally assembled to the busbar holder, reducing labor hours and suppressing yield reductions. In particular, because the relay terminals extending axially between the busbar holder and the circuit board are fixed to the busbar holder by being sandwiched by the terminal holder, displacement can be absorbed at the terminal-fixed portion on the busbar holder side, unlike a configuration in which the relay terminals are fixed to the busbar holder by press-fitting or the like. In this case, the degree of stress absorption of the stress absorbing portion having a bent shape in the first portion can be reduced, and interference between the multiple relay terminals and each other or with other components can be reduced, thereby improving the ease of assembly of the relay terminals and effectively preventing problems such as breakage of the relay terminals.

[0011] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a longitudinal cross-sectional view of a motor, Fig. 2 is a transverse cross-sectional view of the motor, Fig. 3 is a diagram showing the electrical configuration of a control device, Fig. 4 is a plan view of a stator, Fig. 5 is a perspective view illustrating the configuration of a stator core, Fig. 6 is a winding configuration diagram of a stator winding, Fig. 7 is a diagram showing the correspondence between each partial winding of a stator winding and a tooth number, Fig. 8 is a perspective view showing an example of a winding structure of partial windings for a tooth group, and Fig. 9 is a diagram showing a stator winding wound around a stator core. 11 is an exploded perspective view showing the components of the busbar module disassembled, FIG. 12 is a front view showing the busbar module assembled to the stator, FIG. 13 is a diagram showing the state in which a circuit board is assembled to the relay terminal, FIG. 14 is a perspective view showing an example of the configuration of a power line busbar, FIG. 15 is a perspective view showing an example of the configuration of a neutral point busbar, and FIG. 16 is a diagram showing the state in which relay terminals for three phases and terminal holders are integrated. 17 is a perspective view showing a state in which relay terminals for three phases and a terminal holder are integrated together, FIG. 18 is an exploded perspective view showing the relay terminals and the terminal holder in an exploded state, FIG. 19 is a view of the relay terminals and the terminal holder as seen from the second portion side, FIG. 20 is an enlarged plan view showing an assembled portion of the relay terminal in the busbar module, FIG. 21 is a cross-sectional view taken along line 21-21 in FIG. 20, and FIG. 22 is a cross-sectional view of the relay terminals in FIG. 20. 22-22 cross-sectional view, FIG. 23 is a cross-sectional view taken along line 23-23 in FIG. 20, FIG. 24 is an oblique view showing a modified example of a relay terminal, FIG. 25 is a diagram showing the state in which a terminal holder is assembled to the relay terminal, FIG. 26 is an oblique view showing the configuration of a modified example of a terminal holder, FIG. 27 is an oblique view showing the configuration of a modified example of a terminal holder, FIG. 28 is a cross-sectional view showing the configuration of a modified example of a relay terminal, and FIG. 29 is a winding configuration diagram of a stator winding in another example.

[0012] Hereinafter, a rotating electric machine according to an embodiment will be described with reference to the drawings. In the following embodiments, identical or equivalent parts are designated by the same reference numerals in the drawings, and the same explanations are applicable to the parts with the same reference numerals. In this embodiment, a motor 10 is used as an example of a rotating electric machine.

[0013] The motor 10 shown in Fig. 1 is a permanent magnet field motor, specifically a permanent magnet field synchronous machine having three-phase windings. Preferably, two systems of three-phase windings are provided. The motor 10 includes a housing 20, a stator 30 fixed to the housing 20, a rotor 40 that rotates relative to the stator 30, and a rotating shaft 11 to which the rotor 40 is fixed. In the following description, the axial direction refers to the direction in which the rotating shaft 11 extends, the radial direction refers to the direction extending radially from the center of the rotating shaft 11, and the circumferential direction refers to the circumferential direction centered on the rotating shaft 11.

[0014] The housing 20 is cylindrical and accommodates the stator 30, rotor 40, and other components. The housing 20 includes a cylindrical housing main body 21 with a bottom and an end plate 23 fixed to the open end of the housing main body 21. The housing main body 21 and end plate 23 are made of a metal material, such as aluminum. The housing main body 21 has a bottom 22 at its axial end. Cylindrical bosses 22a, 23a are formed at the radial center between the bottom 22 and the end plate 23 of the housing main body 21, extending axially inward toward the housing. Bearings 25, 26 are attached to the bosses 22a, 23a. The bearings 25, 26 rotatably support the rotating shaft 11. The bosses 22a, 23a are bearing fixing portions that fix the bearings 25, 26. An annular cavity 24 is formed around the boss 23a in the end plate 23. An angle sensor 12 is provided on the tip side of the rotary shaft 11. The angle sensor 12 may be a magnetic sensor or a resolver.

[0015] A control device 50 that controls the energization of the motor 10 and a cover 27 that covers the control device 50 are provided on one axial end side of the housing 20 .

[0016] The stator 30 is fixed to the inner peripheral surface of the housing 20, with the axial center of the rotating shaft 11 as its center. The stator 30 forms a magnetic circuit together with the rotor 40. The stator 30 has an annular stator core 31 that is arranged radially opposite the outer periphery of the rotor 40, and a stator winding 32 that is wound around the stator core 31.

[0017] As shown in FIG. 2 , the stator core 31 includes an annular back yoke 33 and a plurality of teeth 34 that protrude radially inward from the back yoke 33 and are arranged at a predetermined distance in the circumferential direction, with slots 35 formed between adjacent teeth 34. The teeth 34 are arranged at equal intervals in the circumferential direction of the stator core 31, and the stator winding 32 is wound around the teeth 34 using concentrated winding. Thus, the conductors of the stator winding 32 are housed in each slot 35. In this embodiment, the number of teeth 34 and the number of slots 35 are both 18. For convenience of explanation, the teeth 34 are numbered T1 to T18 in counterclockwise order in the circumferential direction. When tooth numbers need to be indicated, the teeth 34 may also be referred to as teeth T1, T2, T3, etc. The stator winding 32 is housed and held in the slots 35, and generates magnetic flux when power (AC power) is supplied.

[0018] The stator core 31 is formed by stacking a plurality of thin steel plates (core sheets) that are magnetic bodies in the axial direction of the stator core 31. The steel plates may be formed, for example, by press-punching a strip-shaped electromagnetic steel plate material.

[0019] The rotor 40 constitutes part of the magnetic circuit, has a plurality of magnetic poles in the circumferential direction, and is arranged to face the stator 30 in the radial direction. In this embodiment, the rotor 40 has 14 magnetic poles (i.e., seven magnetic pole pairs). The rotor 40 includes a rotor core 41 made of a magnetic material and permanent magnets 42 fixed to the rotor core 41. Specifically, as shown in FIG. 2 , the rotor 40 includes 14 permanent magnets 42 as magnet portions with alternating polarities in the circumferential direction, and the permanent magnets 42 are embedded in housing holes provided in the rotor core 41 along the axial direction.

[0020] The rotor 40 may have a known configuration, and may be, for example, an IPM (Interior Permanent Magnet) rotor or an SPM (Surface Permanent Magnet) rotor. A rotor with a field winding may also be used as the rotor 40. In this embodiment, an IPM rotor is used. The rotating shaft 11 is inserted into the rotor 40, and the rotor 40 is fixed to the rotating shaft 11 so as to rotate integrally with the rotating shaft 11 around the rotating shaft 11.

[0021] As shown in FIG. 1, the motor 10 is an electromechanical integrated motor, and a control device 50 is provided axially on the side of the stator 30 and the rotor 40. The control device 50 is housed in a cover 27 that is integrally provided with the housing 20. As shown in FIG. 3, the control device 50 includes inverters 51, 52 and a control unit 53 that controls the power supply to the inverters 51, 52. The control unit 53 is primarily configured as a microcomputer including a CPU, ROM, RAM, I / O, etc., and realizes various functions by the CPU executing programs stored in the ROM. Note that the various functions may be realized by electronic circuits, which are hardware, or at least a portion of the functions may be realized by software, i.e., by processing executed on a computer.

[0022] The control unit 53 has a function of controlling the motor 10 (such as controlling the current) based on commands from a higher-level ECU (not shown) and information related to the rotation angle input from the angle sensor 12. The inverters 51 and 52 convert electric power from an external source (such as a battery) and supply it to the motor 10 to generate driving force.

[0023] The control device 50 has a circuit board 55 and various electrical components 56 mounted on the circuit board 55. The electrical components 56 include a microcomputer that constitutes the control unit 53, and semiconductor switching elements and drive circuits that constitute the inverters 51 and 52. The control device 50 is provided on the opposite side of the end plate 23 from the stator 30.

[0024] FIG. 3 is a diagram showing the electrical configuration of the control device 50 in this embodiment.

[0025] In this embodiment, the stator winding 32 has two systems of three-phase windings. That is, the stator winding 32 is composed of a first stator winding 32a and a second stator winding 32b. Inverters 51 and 52 are provided for the stator windings 32a and 32b, respectively. Here, the inverter 51 connected to the first stator winding 32a is also referred to as the first inverter 51, and the inverter 52 connected to the second stator winding 32b is also referred to as the second inverter 52. Each of the inverters 51 and 52 is formed by a full-bridge circuit having the same number of upper and lower arms as the number of phases. A control unit 53 controls the current in each phase by turning on and off switching elements provided in each arm of the inverters 51 and 52.

[0026] More specifically, the first inverter 51 includes a series connection of upper arm switches Sp and lower arm switches Sn as switching elements for each of three phases, namely, U, V, and W phases. In this embodiment, voltage-controlled semiconductor switching elements, specifically, IGBTs, are used as the upper arm switches Sp and lower arm switches Sn for each phase. MOSFETs may also be used as the switching elements. Freewheeling diodes (freewheeling diodes) Dp and Dn are connected in antiparallel to the upper arm switches Sp and lower arm switches Sn for each phase, respectively.

[0027] The high-potential terminal (collector) of the upper arm switch Sp of each phase is connected to the positive terminal of battery B. The low-potential terminal (emitter) of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of battery B. An intermediate connection point between the upper arm switch Sp and the lower arm switch Sn of each phase is connected to one end of the phase winding of each phase in the first stator winding 32a. The first stator winding 32a has phase windings of U, V, and W phases, and in the first inverter 51, one end of the phase winding of each phase is connected to the intermediate connection point between the upper and lower arm switches Sp and Sn.

[0028] The second inverter 52 has a similar configuration to the first inverter 51, and therefore a detailed description thereof will be omitted here. The second stator winding 32b has X-, Y-, and Z-phase windings, and in the second inverter 52, one end of each phase winding is connected to the intermediate connection point of the upper and lower arm switches Sp, Sn, respectively. The three-phase currents supplied from the first inverter 51 and the three-phase currents supplied from the second inverter 52 have a predetermined current phase difference from each other.

[0029] As described above, the motor 10 of this embodiment is a two-system, 14-pole, 18-slot concentrated winding motor.

[0030] The following describes a specific configuration of the stator 30. Fig. 4 is a plan view of the stator 30, and Figs. 5(a) and 5(b) are perspective views for explaining the configuration of the stator core 31.

[0031] In the stator 30, the stator core 31 is composed of a plurality of split cores 61, which are arranged in a line in the circumferential direction to form the stator core 31 into a cylindrical shape. Each split core 61 has a core body 62, which is a laminated body of steel plates, and insulating members 63, 64 made of an insulating resin material or the like. Fig. 5(a) shows the stator core 31 with the insulating members 63, 64 attached, and Fig. 5(b) shows the stator core 31 with the insulating members 63, 64 removed.

[0032] The core body 62 has teeth 34 extending radially of the stator core 31, yoke portions 62a provided on one end thereof, and flange portions 62b provided on the other end thereof. The yoke portions 62a correspond to the back yoke 33 of the stator core 31 shown in FIG. 2. The yoke portions 62a of adjacent split cores 61 may be joined together by adhesive or the like. Insulating members 63, 64 are attached to one and the other axial ends of the teeth 34. The insulating members 63, 64 have upstanding portions 63a, 64a extending axially radially outward (toward the back yoke 33) of the teeth 34. The upstanding portions 63a, 64a are each provided with grooves 63b, 64b at two circumferential locations, through which the conductor material of the stator winding 32 can be inserted.

[0033] By lining up the split cores 61 in the circumferential direction, the teeth 34 and slots 35 are arranged alternately in the circumferential direction, as shown in Fig. 2. In this embodiment, the stator core 31 is made up of 18 split cores 61. As shown in Fig. 4, the stator winding 32 is made up of conductive wire wound around each tooth 34 using concentrated winding. However, Fig. 4 shows only one example of the winding structure for each tooth 34, and does not necessarily match the winding structure described below. The winding structure in this embodiment will be described in detail later.

[0034] An example of the electrical configuration of the stator winding 32 is shown in Figure 6. Figure 6(a) shows the configuration of the U-, V-, and W-phase windings in the first stator winding 32a, and Figure 6(b) shows the configuration of the X-, Y-, and Z-phase windings in the second stator winding 32b. In each of these stator windings 32a, 32b, the phase windings of each phase are connected to each other by star connection (Y connection).

[0035] 6(a), the first stator winding 32a has partial windings U1, U2, U3, and U4 as a U-phase phase winding, partial windings V1, V2, V3, and V4 as a V-phase phase winding, and partial windings W1, W2, W3, and W4 as a W-phase phase winding. One end of the series-connected partial windings U1 and U2, one end of the series-connected partial windings V1 and V2, and one end of the series-connected partial windings W1 and W2 are connected to one another at a neutral point N1a, and one end of the series-connected partial windings U3 and U4, one end of the series-connected partial windings V3 and V4, and one end of the series-connected partial windings W3 and W4 are connected to one another at a neutral point N1b.

[0036] 6(b), the second stator winding 32b has partial windings X1, X2, X3, and X4 as the X-phase winding, partial windings Y1, Y2, Y3, and Y4 as the Y-phase winding, and partial windings Z1, Z2, Z3, and Z4 as the Z-phase winding. One end of the series-connected partial windings X1 and X2, one end of the series-connected partial windings Y1 and Y2, and one end of the series-connected partial windings Z1 and Z2 are connected to one another at a neutral point N2a, and one end of the series-connected partial windings X3 and X4, one end of the series-connected partial windings Y3 and Y4, and one end of the series-connected partial windings Z3 and Z4 are connected to one another at a neutral point N2b.

[0037] The partial windings U1 to U4, V1 to V4, and W1 to W4 of each phase in the first stator winding 32a and the partial windings X1 to X4, Y1 to Y4, and Z1 to Z4 of each phase in the second stator winding 32b are wound by concentrated winding around the teeth 34 of the stator core 31. In this embodiment, the 12 partial windings of the first stator winding 32a and the 12 partial windings of the second stator winding 32b are distributed and wound around the 18 teeth 34 of the stator core 31. This point will be described in detail below.

[0038] In the stator core 31, the total of 18 teeth 34 are divided into three tooth groups, and partial windings of two phase windings of different phases are wound around three teeth 34 in each tooth group. That is, in the stator 30, as shown in Fig. 4, all of the teeth 34 (T1 to T18) of the stator core 31 are divided into six tooth groups G1 to G6, and the phase windings of each phase are wound around the tooth groups G1 to G6 that are arranged circumferentially to form the stator windings 32a and 32b. Two partial windings from the partial windings U1 to U4, V1 to V4, and W1 to W4 of the first stator winding 32a and two partial windings from the partial windings X1 to X4, Y1 to Y4, and Z1 to Z4 of the second stator winding 32b are wound around each tooth group G1 to G6 in an assigned state. In this case, in each of the tooth groups G1 to G6, a partial winding of the first stator winding 32a is wound around one of the three teeth 34 on both sides in the circumferential direction, and a partial winding of the second stator winding 32b is wound around the other tooth 34. Furthermore, the tooth 34 at the center of each of the tooth groups G1 to G6 is wound with the partial windings of both the first and second stator windings 32a, 32b.

[0039] In each of teeth groups G1 to G6, if the three consecutive teeth 34 arranged circumferentially are designated in circumferential order as the first teeth, second teeth, and third teeth, a partial winding of a first phase winding of the multiple phase windings is wound continuously around the first and second teeth, and a partial winding of a second phase winding of the multiple phase windings is wound continuously around the second and third teeth. The second tooth, which is the center of the three consecutive teeth 34, is a common tooth around which both the first and second phase windings are wound.

[0040] 7 is a diagram showing the correspondence between the partial windings of the stator windings 32a and 32b and the teeth T1 to T18. In FIG. 7, for example, in tooth group G1, the partial winding W1 of the first stator winding 32a is wound around tooth T1, the partial winding W2 of the first stator winding 32a and the partial winding X2 of the second stator winding 32b are wound around tooth T2, and the partial winding X1 of the second stator winding 32b is wound around tooth T3. These teeth T1 to T3 correspond to the first to third teeth. The other tooth groups G2 to G6 will not be described here, but partial windings are wound in a similar manner, with three teeth in each of the tooth groups G2 to G6 corresponding to the first to third teeth, respectively.

[0041] Each of the tooth groups G1 to G6 shown in Fig. 7 includes three pairs of tooth groups, each pair being tooth groups that form the same combination of two-phase phase windings. Specifically, in tooth groups G1 and G4, the W-phase winding and the X-phase winding are combined as the combination of two-phase phase windings. In tooth groups G2 and G5, the V-phase winding and the Z-phase winding are combined as the combination of two-phase phase windings, and in tooth groups G3 and G6, the U-phase winding and the Y-phase winding are combined as the combination of two-phase phase windings.

[0042] The tooth groups that have the same combination of phase windings for two phases, i.e., tooth groups G1 and G4, tooth groups G2 and G5, and tooth groups G3 and G6, are each positioned 180 degrees apart from each other in the circumferential direction (see Figure 4).

[0043] Next, the winding structure of the phase windings (partial windings) in each of the tooth groups G1 to G6 will be described.

[0044] Fig. 8 is a perspective view showing an example of the winding structure of partial windings for one tooth group G. Fig. 8 illustrates the winding structure of tooth group G1, which includes teeth T1 to T3. In tooth group G1, partial windings W1 and W2 are wound around teeth T1 and T2 using conductor C1 as a W-phase winding, and partial windings X1 and X2 are wound around teeth T2 and T3 using conductor C2 as an X-phase winding. Of the W-phase winding and X-phase winding, the X-phase winding is the first-wound phase winding during winding, and the W-phase winding is the last-wound phase winding. Each of the conductors C1 and C2 is a coated conductor in which a conductor is covered with an insulating coating, such as a round wire.

[0045] When winding the X-phase winding, which is a pre-wound winding, the conductor wire C2 is wound around tooth T3 and then tooth T2 in tooth group G1. At this time, the conductor wire C2 is wound around teeth T3 and T2 in opposite directions. The conductor wire end at the winding start side and the conductor wire end at the winding end side form lead-out portions H21 and H22 drawn out in the axial direction. Furthermore, the conductor wire C2 has a crossover portion H23 between the two winding sections X1 and X2, which is preferably guided by an insulating member 63 provided on each split core 61. Specifically, the crossover portion H23 is preferably guided outward from the upright portion 63a via a groove 63b in the insulating member 63, i.e., on the opposite side of the tooth across the upright portion 63a. The crossover portion H23 is guided to the outside of the standing portion 63a, so that the crossover portion H23 of the conductor C2 does not interfere with the winding of the conductor C1 which is wound later.

[0046] Furthermore, when winding the W-phase winding, which is a post-winding winding, the wire C1 is wound around tooth T1 and then tooth T2 in tooth group G1. At this time, the wire C1 is wound around teeth T1 and T2 in opposite circumferential directions. The wire end at the winding start side and the wire end at the winding end side of the wire C1 form lead-out portions H11 and H12 drawn out in the axial direction. Note that, unlike the lead-out portion H23, the crossover portion H13 between the two winding portions W1 and W2 of the wire C1 does not need to be guided by the insulating member 63. This is because the W-phase phase winding is a post-winding winding.

[0047] Fig. 9 is a perspective view showing the state in which the stator winding 32 is wound around the stator core 31. In Fig. 9, the conductor end portion 36 of each partial winding wound around each tooth 34 is extended in the axial direction. The conductor end portion 36 corresponds to the lead-out portions H11, H12, H21, and H22 described in Fig. 8. In this embodiment, four conductor end portions 36 are provided per tooth group G, meaning a total of 24 conductor end portions 36 are provided for all six tooth groups G.

[0048] A busbar module 70 is attached to one axial end of the stator 30, and the configuration of the busbar module 70 will be described below. Fig. 10 is a perspective view of the busbar module 70, and Fig. 11 is an exploded perspective view showing the components of the busbar module 70. Fig. 12 is a front view showing the busbar module 70 attached to one axial end of the stator 30.

[0049] The busbar module 70 includes a plurality of power busbars 71 for each phase, a plurality of neutral busbars 72, a plurality of relay terminals 73 connected to the power busbars 71 of each phase, a busbar holder 74 to which the busbars 71, 72, and the relay terminals 73 are attached, and a terminal holder 75 to hold the relay terminals 73 when attached to the busbar holder 74. The power busbars 71 and the neutral busbars 72 are made of elongated metal plates, with the plate surfaces extending axially and forming an arc shape in a plan view. The power busbars 71 are conductive members that connect the partial windings of the same phase to each other, and the neutral busbars 72 are conductive members that connect the partial windings of each phase by star connection. Each relay terminal 73 is made of a long conductor. The busbar holders 74 and the terminal holders 75 are each made of an insulating material, specifically, a synthetic resin material.

[0050] The power line bus bars 71 are made up of bus bars for six phases of each stator winding 32a, 32b. That is, the power line bus bars 71 include U-phase bus bars, V-phase bus bars, and W-phase bus bars, which are bus bars for each phase of the first stator winding 32a, and X-phase bus bars, Y-phase bus bars, and Z-phase bus bars, which are bus bars for each phase of the second stator winding 32b. Each power line bus bar 71 electrically connects partial windings of the same phase. The neutral point bus bars 72 include two neutral point bus bars corresponding to the neutral points N1a and N1b of the first stator winding 32a shown in FIG. 6(a) and two neutral point bus bars corresponding to the neutral points N2a and N2b of the second stator winding 32b shown in FIG. 6(b).

[0051] The relay terminals 73 are arranged in two circumferential positions in the busbar module 70, each consisting of three relay terminals. The relay terminals 73 include a U-phase terminal, a V-phase terminal, and a W-phase terminal, which are relay terminals 73 for each phase of the first stator winding 32a, and an X-phase terminal, a Y-phase terminal, and a Z-phase terminal, which are relay terminals 73 for each phase of the second stator winding 32b. For example, in FIG. 10 , the three relay terminals 73 shown in the upper right are relay terminals 73A for the U, V, and W phases, and the three relay terminals 73 shown in the lower left are relay terminals 73B for the X, Y, and Z phases. For each phase, the relay terminal 73 is connected to the power line busbar 71, and the power line busbar 71 and the relay terminal 73 are electrically conductive to each other. The relay terminals 73 are conductive members that connect the stator windings 32a and 32b to the inverters 51 and 52 of the control device 50. More specifically, one longitudinal end of the relay terminal 73 is electrically connected to the power line bus bar 71 of each phase, and the other longitudinal end is electrically connected to the circuit board 55 of the control device 50.

[0052] Fig. 13 is a diagram showing a state in which the circuit board 55 is assembled to the relay terminals 73 extending axially from the busbar holder 74. As shown in Fig. 13, a through hole 55a is formed in the circuit board 55, and the tip end portion of the relay terminal 73 (a connection end portion 105 described below) is inserted into the through hole 55a. The relay terminal 73 is electrically connected to the circuit board 55 by solder or the like. The circuit board 55 is fixed to the end plate portion 23 of the housing 20 by fasteners 57 such as screws.

[0053] As shown in Figure 11, the busbar holder 74 is formed in an annular shape. The busbar holder 74 is provided with a plurality of busbar accommodating grooves 111 extending circumferentially and aligned radially. The spaces between the busbar accommodating grooves 111 in the busbar holder 74 form isolation walls that insulate and isolate the radially aligned busbars. The busbar accommodating grooves 111 are busbar accommodating portions that accommodate the power line busbar 71 and the neutral point busbar 72. The busbar accommodating grooves 111 open on one of the axially opposite faces of the busbar holder 74, i.e., on the face opposite the stator, and are each formed in an arc shape with a length equivalent to approximately a semicircle.

[0054] A plurality of through holes 112 that penetrate in the axial direction (thickness direction of the busbar holder 74) are provided on the outer edge portion of the busbar holder 74, i.e., radially outward of each busbar accommodating groove 111. These through holes 112 are conductor passage holes through which the lead-out portions drawn out in the axial direction from the partial windings of each phase, i.e., the conductor end portions 36 shown in Fig. 9, are inserted. The number of through holes 112 provided is the same as the number of partial windings of the stator winding 32, and in this embodiment, 24 through holes 112 are provided in the circumferential direction.

[0055] The busbar holder 74 is provided with a plurality of legs 113 extending in the axial direction at predetermined intervals in the circumferential direction. As shown in Fig. 12, when the busbar module 70 is assembled to the stator 30, each leg 113 is disposed radially outside an insulating member 63 provided at the coil end of the stator 30, and the tip of each leg 113 abuts against the axial end face of the stator core 31. As a result, the busbar module 70 is coaxial with the stator 30 and is provided at a predetermined height from the axial end face of the stator core 31. The integrated body of the stator 30 and the busbar module 70 corresponds to a stator unit.

[0056] 11 , the busbar holder 74 is provided with terminal mounting portions 114 to which the relay terminals 73, each consisting of a group of three, are mounted by the terminal holder 75. The terminal mounting portions 114 are provided at two locations approximately 180° apart in the circumferential direction, one of which is a terminal mounting portion 114 to which the relay terminals 73A for the U-, V-, and W-phases of the first stator winding 32a are mounted, and the other is a terminal mounting portion 114 to which the relay terminals 73B for the X-, Y-, and Z-phases of the second stator winding 32b are mounted. However, a specific configuration for mounting the relay terminals 73 on the terminal mounting portions 114 will be described later.

[0057] FIG. 14 is a perspective view showing an example of the configuration of the power line bus bar 71, and FIG. 15 is a perspective view showing an example of the configuration of the neutral point bus bar 72.

[0058] 14 , the power bus bar 71 has a main body portion 81 extending in an arc shape, a plurality of press-fit fixing portions 82 extending axially from the main body portion 81 and press-fitted and fixed to the bus bar holder 74, and a plurality of arm portions 83 extending radially outward from the main body portion 81. The press-fit fixing portions 82 are provided at three locations spaced apart from one another in the circumferential direction. When the power bus bar 71 is accommodated in the bus bar accommodating groove 111 of the bus bar holder 74, the press-fit fixing portions 82 are inserted into insertion holes (not shown) provided at the bottom of the bus bar accommodating groove 111 in the bus bar holder 74. This allows the power bus bar 71 to be press-fitted and fixed to the bus bar holder 74.

[0059] Each arm portion 83 is a conductor connection portion that is electrically connected to the conductor end portion 36 of the stator winding 32 when the conductor end portion 36 is inserted into the through hole 112 in the bus bar holder 74. A folded portion 83a that is folded back in a substantially U-shape is formed at the tip of each arm portion 83, and the folded portion 83a is electrically connected to the conductor end portion 36 by welding or the like.

[0060] The power line bus bar 71 has an upright portion 84 extending axially from the main body 81, and a joining terminal portion 85 is provided at the tip of the upright portion 84 as a portion to be joined to the relay terminal 73 shown in Fig. 10 etc. In the power line bus bar 71, the press-fit fixing portion 82 and the upright portion 84 are provided so as to protrude in opposite directions to each other in the axial direction.

[0061] The power line bus bars 71 for each phase all have a common configuration in that they have a main body 81, a plurality of press-fit fixing portions 82, a plurality of arm portions 83, standing portions 84, and connecting terminal portions 85. However, the positions of the press-fit fixing portions 82 and the connecting terminal portions 85 in the longitudinal direction of the main body 81 are individually different for the power line bus bars 71 for each phase. Furthermore, the length and shape of the arm portions 83 in each power line bus bar 71 differ depending on the radial arrangement position and the position of the conductor end portions 36 of the partial windings to which they are connected.

[0062] 15 , the neutral point bus bar 72 has a main body 91 extending in an arc shape, a plurality of press-fit fixing portions 92 extending axially from the main body 91 and press-fitted into the bus bar holder 74, and a plurality of arm portions 93 extending radially outward from the main body 91. The press-fit fixing portions 92 are provided at three locations spaced apart from one another in the circumferential direction. When the neutral point bus bar 72 is accommodated in the bus bar accommodating groove 111 of the bus bar holder 74, the press-fit fixing portions 92 are inserted into insertion holes (not shown) provided at the bottom of the bus bar accommodating groove 111 in the bus bar holder 74. This causes the neutral point bus bar 72 to be press-fitted into the bus bar holder 74.

[0063] Each arm portion 93 is a conductor connection portion that is electrically connected to the conductor end portion 36 of the stator winding 32 when the conductor end portion 36 is inserted into the through hole 112 in the bus bar holder 74. A folded portion 93a that is folded back in a substantially U-shape is formed at the tip of each arm portion 93, and the folded portion 93a is electrically connected to the conductor end portion 36 by welding or the like.

[0064] Next, the configuration of the relay terminal 73 and the mounting structure of the relay terminal 73 using the terminal holder 75 will be described. Figures 16 and 17 are perspective views showing the state in which the relay terminals 73 for three phases and the terminal holder 75 are integrated. Figures 16 and 17 show the configurations viewed from opposite directions. Figure 18 is an exploded perspective view showing the relay terminal 73 and the terminal holder 75.

[0065] 16 and 17 , each set of three relay terminals 73 is integrated by a terminal holder 75, and in this state, is assembled to a busbar holder 74 (see FIG. 10 ). In other words, the busbar module 70 has a holding structure in which the terminal holder 75 holds each relay terminal 73.

[0066] 18 , the relay terminal 73 has, in its longitudinal direction, a first portion 101 extending in the axial direction, a second portion 102 bent from an end (the lower end in the figure) of the first portion 101, and a third portion 103 bent from an end of the second portion 102. One axial end of the first portion 101 is a connection end 105 fixed to the circuit board 55, and the other axial end is continuous with the second portion 102. The first portion 101 extends in the axial direction, and the second portion 102 is bent from the first portion 101 in a direction extending radially. The third portion 103 is bent from the second portion 102 in a direction extending axially.

[0067] In the relay terminal 73, the second portion 102 is a longitudinally intermediate portion, and both sides of the second portion 102 are the first portion 101 and the third portion 103. That is, one of the two sides of the second portion 102 in the longitudinal direction of the relay terminal 73 is the first portion 101, and the opposite side of the first portion 101 is the third portion 103. In the relay terminal 73, the first portion 101 and the third portion 103 each extend in the axial direction and are arranged to face each other. The relay terminal 73 is generally J-shaped in side view.

[0068] In the relay terminal 73, the tip of the first portion 101, which is one longitudinal end, is a connection end portion 105 that is fixed to the circuit board 55, and the third portion 103, which is the other longitudinal end, is a joining terminal portion that is joined to the joining terminal portion 85 of the power line bus bar 71. All three relay terminals 73 have the same configuration.

[0069] The first portion 101 of the relay terminal 73 is provided with a bent stress absorbing portion 107. The stress absorbing portion 107 is a portion formed by being bent in a wavy shape in the circumferential direction in opposite directions, so that when stress acts on the relay terminal 73 in at least one of the axial direction, radial direction, and circumferential direction, the stress is absorbed by the stress absorbing portion 107. The relay terminal 73 may be formed, for example, by punching a flat plate material, and then bending the second portion 102 and the third portion 103 relative to the first portion 101.

[0070] The terminal holder 75 also has an elongated main body 121 extending in the direction in which the three relay terminals 73 are arranged. The main body 121 is provided with a plurality of guide portions 122 at predetermined intervals along its longitudinal direction. The guide portions 122 are portions that enable each relay terminal 73 to be individually clamped, and the spaces between the guide portions 122 form assembly recesses 123 into which the three relay terminals 73 are assembled. The assembly recesses 123 are provided on three sides of the cross section of the terminal holder 75, and the first portion 101, the second portion 102, and the third portion 103 can be assembled into the assembly recesses 123, respectively. In other words, when the terminal holder 75 and the relay terminals 73 are integrated, the guide portions 122 are interposed between the relay terminals 73 arranged in the circumferential direction.

[0071] When the relay terminals 73 are assembled in the respective assembly recesses 123 of the terminal holder 75, the positions of the relay terminals 73 are restricted by the terminal holder 75, and the relay terminals 73 are arranged at equal intervals in the circumferential direction. As a result, even if the stress absorbing portions 107 in the first portions 101 of the relay terminals 73 are bent in the circumferential direction, i.e., even if the stress absorbing portions 107 of the relay terminals 73 are bent so as to approach each other, the relay terminals 73 are prevented from coming into contact with each other.

[0072] Fig. 19 is a view of the terminal holder 75, with the relay terminal 73 integrated therewith, viewed in the axial direction from the side of the second portion 102 of the relay terminal 73. As shown in Fig. 19, a plurality of guide portions 122 provided in the terminal holder 75 to sandwich the second portion 102 of the relay terminal 73 have convex portions 124 on opposing surfaces 122a facing the second portion 102, which are deformable when in contact with the second portion 102. Although Fig. 19 shows one convex portion 124 on each opposing surface 122a of the guide portions 122, a plurality of convex portions 124 may be provided. The convex portions 124 correspond to the convex, easily deformable portions.

[0073] In the terminal holder 75, a distance D1 between the guide portions 122 in the arrangement direction of the relay terminals 73 is larger than a width D2 of the second portion 102 of the relay terminal 73 (D1 > D2). Furthermore, in the natural state of the terminal holder 75 (i.e., when the relay terminals 73 are not installed), a distance D3 (not shown) between the opposing surface 122a of the guide portion 122 and the protrusion 124 is smaller than the width D2 of the second portion 102 (D3 > D2). Therefore, when the relay terminals 73 are installed in the installation recesses 123 of the terminal holder 75, the second portion 102 of the relay terminal 73 is pressed against the opposing surface 122a of the guide portion 122 due to elastic deformation of the resin of the protrusion 124. This allows the relay terminals 73 to be positioned in a predetermined installation position and temporarily held when the relay terminals 73 are installed in the terminal holder 75.

[0074] The terminal holder 75 may be provided with a protrusion 124 on each of the opposing surfaces 122a on both sides that sandwich the second portion 102 of the relay terminal 73. In addition to or instead of the configuration in which the protrusion 124 is provided on the opposing surface 122a on the terminal holder 75 side, a convex, easily deformable portion (protrusion) that is deformable in a contact state may be provided on the second portion 102 side of the relay terminal 73.

[0075] Fig. 20 is an enlarged plan view showing an assembled portion of the relay terminals 73 in the busbar module 70. Fig. 21 is a cross-sectional view taken along line 21-21 in Fig. 20, Fig. 22 is a cross-sectional view taken along line 22-22 in Fig. 20, and Fig. 23 is a cross-sectional view taken along line 23-23 in Fig. 20. Each set of three relay terminals 73 is arranged side by side in the circumferential direction, and is fixed together to the busbar holder 74 with the second portions 102 sandwiched between the busbar holder 74 and the terminal holder 75.

[0076] As a mounting structure for the relay terminals 73 in the busbar module 70, the terminal holder 75 is provided with an engaging portion 125 that can engage with the busbar holder 74. The engaging portion 125 is provided to extend axially from the main body portion 121. Meanwhile, the terminal mounting portion 114 of the busbar holder 74 is provided with an engaged portion 115 with which the engaging portion 125 of the busbar holder 74 engages (see also FIG. 11 ). The engaged portion 115 on the busbar holder 74 side and the engaging portion 125 on the terminal holder 75 side are each provided at two locations in the circumferential direction. In this embodiment, the busbar holder 74 and the terminal holder 75 are connected by a snap fit using the elasticity of the resin material, and the engaged portion 115 on the busbar holder 74 side and the engaging portion 125 on the terminal holder 75 side are engaged with each other, thereby enabling the terminal holder 75 to be fixed to the busbar holder 74.

[0077] In this embodiment, the engaged portion 115 on the busbar holder 74 side is shaped like a hook, and the engaging portion 125 on the terminal holder 75 side is shaped like a hook receiver. However, the engagement structure between the busbar holder 74 and the terminal holder 75 is not limited to this. For example, the engaged portion 115 on the busbar holder 74 side may be shaped like a hook receiver, and the engaging portion 125 on the terminal holder 75 side may be shaped like a hook.

[0078] In the terminal mounting portion 114 of the busbar holder 74, the surface that faces closely to the second portion 102 when the relay terminal 73 is mounted is a flat surface 116 (see FIG. 11 ). Therefore, as shown in FIG. 21 , when the relay terminal 73 and the terminal holder 75 are mounted integrally to the terminal mounting portion 114 of the busbar holder 74, the second portion 102 of each relay terminal 73 is sandwiched between the flat surface 116 on the busbar holder 74 side and the main body 121 of the terminal holder 75.

[0079] 22 and 23 , when the integral assembly of the relay terminal 73 and the terminal holder 75 is attached to the terminal attachment portion 114 of the busbar holder 74, the joining terminal portion 85 of the power line busbar 71 and the third portion 103 of the relay terminal 73 overlap each other. The joining terminal portion 85 and the third portion 103 are joined to each other by welding. Note that the joining terminal portion 85 of the power line busbar 71 and the third portion 103 of the relay terminal 73 may be joined to each other by means other than welding, such as welding or brazing.

[0080] As described above, the second portion 102 of each relay terminal 73 is held by the engagement of the terminal holder 75 with the busbar holder 74, and the first portion 101 and the third portion 103, which are on both sides of the second portion 102, are fixed by welding or the like. In other words, each relay terminal 73 has a holding structure in which both longitudinal end portions are firmly fixed and the intermediate portion is capable of slight displacement. As a result, the stress load generated in the relay terminal 73, i.e., the stress transmitted from the circuit board 55 and the busbar holder 74, is dispersed between the stress absorbing portion 107 of the first portion 101 and the portion of the second portion 102 held by the terminal holder 75.

[0081] Incidentally, as a configuration for fixing the relay terminals 73 to the busbar holder 74, other than a configuration using the terminal holder 75, a configuration is conceivable in which, for example, the axial end of the first portion 101 of the relay terminal 73 is fixed to the busbar holder 74 by press-fitting, welding, or the like. Specifically, a configuration is envisioned in which one end of the first portion 101 of the relay terminal 73 is fixed to the circuit board 55, and the other end of the first portion 101 is press-fitted and fixed to the busbar holder 74. This configuration raises concerns about increased labor costs due to press-fitting and fixed fixing of each relay terminal 73, as well as reduced yields due to misalignment during press-fitting. Furthermore, because both end portions of the first portion 101 are firmly fixed to the relay terminal 73, all stress absorption in the relay terminal 73 relies on the bent portion (stress absorbing portion). Therefore, to ensure sufficient stress absorption, the degree of bending must be large, which results in concerns about interference between components.

[0082] In contrast, in the present embodiment, in the relay terminal 73, one end of the first portion 101 is fixed to the circuit board 55, but the other end of the first portion 101, the second portion 102, is held by being sandwiched by the terminal holder 75, allowing slight relative displacement of the second portion 102 with respect to the busbar holder 74. In other words, in the relay terminal 73, the end of the first portion 101 on the busbar holder 74 side is not fixed by press-fitting or welding. With this configuration, stress absorption in the relay terminal 73 can be distributed between the stress absorbing portion 107, which is the bent portion of the first portion 101, and the portion where the second portion 102 is sandwiched by the terminal holder 75. Therefore, the degree of bending in the stress absorbing portion 107 can be reduced. Furthermore, in the configuration described above in which the relay terminal 73 is not press-fit or welded to the busbar holder 74, there is no need to adjust the positioning accuracy of the relay terminal 73 when assembling it to the busbar holder 74, which reduces labor costs and prevents a decrease in yield.

[0083] Furthermore, in a configuration in which the stress absorbing portion 107 is provided in the relay terminal 73, it becomes necessary to secure space in the axial direction for the stress absorbing portion 107, which raises concerns that the motor shaft length may become excessively long. In this regard, in this embodiment, the stress absorbing portion 107 of the relay terminal 73 is disposed in a cavity 24 formed around the boss portion 23a in the end plate portion 23 of the housing 20. This configuration will be described with reference to FIG.

[0084] 12 , the housing 20, which is assembled to the stator unit consisting of the stator 30 and the busbar module 70, is simply shown by phantom lines. As described above, the end plate 23 of the housing 20 has an annular cavity 24 formed around the boss 23 a (see FIG. 1 ), and at least a portion of the stress absorbing portion 107 of the relay terminal 73 is housed in the cavity 24. In this case, the stress absorbing portion 107 is provided in a position aligned radially inward and outward with the bearing 26, which provides the relay terminal 73 with a desired stress relaxation structure while preventing the motor shaft length from becoming excessively long.

[0085] However, noise and vibration due to torque ripple are a problem in rotating electrical machines. Torque ripple is primarily caused by the sixth-order harmonic component or the twelfth-order harmonic component, so it is desirable to suppress these. Therefore, when using the motor 10 configured as described above, the following control can be performed by the control device 50.

[0086] In the motor 10 configured as described above, the U-phase, V-phase, and W-phase partial windings (first coil bodies) of the first stator winding 32a are wound around the first teeth (T1, T4, T7, T10, T13, T16) of each teeth group, the first teeth (T2, T5, T8, T11, T14, T17) of each teeth group are wound with one phase partial winding (second coil body) of each of the first and second stator windings 32a, 32b, and the X-phase, Y-phase, and Z-phase partial windings (third coil body) of the second stator winding 32b are wound around the third teeth (T3, T6, T9, T12, T15, T18) of each teeth group.

[0087] In this configuration, the control device 50 sets the combined phase difference between the magnetomotive force generated by the partial winding of the first stator winding 32a wound around the second teeth and the magnetomotive force generated by the partial winding of the second stator winding 32b wound around the second teeth so that the phase difference between the magnetomotive force of the second coil body of each phase relative to the magnetomotive force of the first coil body of each phase and the phase difference between the magnetomotive force of the third coil body of each phase relative to the magnetomotive force of the second coil body of each phase are within a predetermined phase range including 20 degrees in electrical angle, or so that the phase difference between the magnetomotive force of the third coil body of each phase relative to the magnetomotive force of the first coil body of each phase and the phase difference between the magnetomotive force of the second coil body of each phase relative to the magnetomotive force of the third coil body of each phase are within a predetermined phase range including 20 degrees in electrical angle. The combined phase difference may be set, for example, in the range of 72 to 88 degrees in electrical angle. Alternatively, the control device 50 sets a combined phase difference between the current flowing through the partial winding of the first stator winding 32a wound around the second teeth and the current flowing through the partial winding of the second stator winding 32b wound around the second teeth. Details of this control are described in Japanese Patent No. 7103299 filed by the applicant of the present application.

[0088] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0089] Each relay terminal 73 provided in the busbar module 70 is configured to have a first portion 101 extending in the axial direction and having one end fixed to the circuit board 55, and a bent stress absorbing portion 107 is provided in the first portion 101. Therefore, even if unnecessary stress acts on the relay terminal 73 between the power line busbar 71 and the circuit board 55, the stress is alleviated by the bent shape of the stress absorbing portion 107. Furthermore, the multiple relay terminals 73 are arranged side by side in the circumferential direction, and the second portions 102 bent radially from the first portion 101 are sandwiched between the busbar holder 74 and the terminal holder 75, and are fixed together to the busbar holder 74. Therefore, the multiple relay terminals 73 can be integrally assembled to the busbar holder 74, reducing the number of steps and suppressing a decrease in yield. In particular, because the relay terminals 73 extending axially between the busbar holder 74 and the circuit board 55 are fixed to the busbar holder 74 by being sandwiched between the terminal holder 75, displacement can be absorbed at the terminal fixed portion on the busbar holder 74 side, unlike a configuration in which the relay terminals 73 are fixed to the busbar holder 74 by press-fitting or the like. In this case, the degree of stress absorption by the bent stress absorbing portion 107 in the first portion 101 can be reduced, making it less likely that the multiple relay terminals 73 will interfere with each other or with other components. As a result, the ease of assembly of the relay terminals 73 can be improved, while favorably suppressing problems such as breakage of the relay terminals 73.

[0090] The relay terminal 73 is configured such that the first portion 101 and the third portion 103, which are on one side and the other side of the second portion 102, are fixed to the circuit board 55 and the power line bus bar 71, respectively. In this case, in the relay terminal 73, the connection end 105 of the first portion 101 connected to the circuit board 55 and the third portion 103 fixed to the power line bus bar 71 are positioned apart from each other across the second portion 102. Therefore, even if the fixed end (connection end 105) on the circuit board 55 side and the fixed end (third portion 103) on the power line bus bar 71 side of the relay terminal 73 are affected by vibrations of the motor 10, damage to the relay terminal 73 due to such effects can be suppressed.

[0091] In each relay terminal 73, the third portion 103 is provided so as to extend in the axial direction and face the first portion 101, and the terminal holder 75 is attached in a state sandwiched between the first portion 101 and the third portion 103. In this case, the first portion 101 and the third portion 103 of the relay terminal 73 face the terminal holder 75 from opposite directions, thereby suppressing radial positional deviation of the relay terminal 73.

[0092] The busbar holder 74 and the terminal holder 75 are connected by a snap fit, in which the engaged portion 115 on the busbar holder 74 engages with the engaging portion 125 on the terminal holder 75. The second portion 102 of each relay terminal 73 is sandwiched between the main body 121 of the terminal holder 75 and the busbar holder 74. In this configuration, the second portion 102 of each relay terminal 73 is held by the engagement of the terminal holder 75 with the busbar holder 74, and the first portion 101 and the third portion 103 on either side of the second portion 102 are fixed by welding or the like. In other words, each relay terminal 73 has a holding structure in which both longitudinal ends are firmly fixed, while the intermediate portion is capable of slight deformation. This allows stress loads generated in the relay terminal 73 to be suitably distributed between the stress absorbing portion 107 and the portion of the terminal holder 75 that holds the second portion 102.

[0093] A convex portion 124 serving as an easily deformable portion is provided on at least one side of the second portion 102 of the relay terminal 73 and the guide portion 122 of the terminal holder 75, which are opposed to each other in the circumferential direction. This allows the relay terminal 73 to be positioned at a predetermined assembly position when the relay terminal 73 is assembled to the terminal holder 75, and also makes it possible to temporarily hold the relay terminal 73.

[0094] Furthermore, by providing the convex portion 124 as the easily deformable portion on the second portion 102 of the relay terminal 73, it is possible to ensure the positional accuracy of the relay terminal 73 at a location away from the third portion 103, which is the welding location of the relay terminal 73. In other words, it is possible to suppress the occurrence of misalignment due to the heat of welding during the welding operation.

[0095] In a configuration in which stress absorbing portion 107 is provided in first portion 101 of relay terminal 73, it becomes necessary to secure axial accommodation space for stress absorbing portion 107, which raises concerns about excessively long axial length of motor 10. In this regard, by forming an annular hollow portion 24 around boss portion 23a (bearing fixing portion) in end plate portion 23 and accommodating at least a portion of stress absorbing portion 107 of relay terminal 73 in hollow portion 24, it is possible to provide relay terminal 73 with the desired stress absorption structure while preventing the axial length of motor 10 from becoming excessively long.

[0096] (Other Embodiments) The above embodiment may be modified as follows, for example.

[0097] 24 , the first portion 101 of each relay terminal 73 may have a radially bent portion 107a bent in the radial direction as the stress absorbing portion 107. The radially bent portion 107a is bent in the radial direction so as to overlap the second portion 102 when viewed in the axial direction. In this case, there is a concern that when assembling the terminal holder 75 to each relay terminal 73, interference with the radially bent portion 107a of the relay terminal 73 may make it difficult to assemble the terminal holder 75.

[0098] 25 , when the axial distance from the tip of the third portion 103 to the radially bent portion 107a in the relay terminal 73 is L1 and the axial length of the terminal holder 75 is L2, L1 and L2 are set to satisfy the relationship L1 > L2. Note that the length L2 of the terminal holder 75 is the length of the terminal holder 75 at its longest position in the axial direction, and here it is the length of the longest of the guide portions 122 arranged between the third portions 103 of the relay terminals 73. This configuration enhances the stress absorption effect of the relay terminal 73 and allows the relay terminal 73 to be properly assembled to the busbar holder 74.

[0099] In the first portion 101 of each relay terminal 73, the bent stress absorbing portion 107 may be bent only in the radial direction out of the circumferential direction and the radial direction.

[0100] 26 , the terminal holder 75 may have an alignment structure that circumferentially aligns the third portion 103 of the relay terminal 73 with the joining terminal portion 85 of the power line bus bar 71. Specifically, in the terminal holder 75, the radial protrusion amount of a guide portion 122A that protrudes radially and is circumferentially adjacent to the third portion 103 of the relay terminal 73 is set to be larger than that of the configurations shown in FIGS. 10 and 16 , and the guide portion 122A circumferentially aligns the third portion 103 of the relay terminal 73 with the joining terminal portion 85 of the power line bus bar 71 in an overlapping state. Note that the guide portion 122 corresponds to the “alignment protrusion.”

[0101] This allows the joining terminal portion 85 of the power line busbar 71 to be appropriately aligned with the third portion 103 of the relay terminal 73 attached to the busbar holder 74 by the terminal holder 75, thereby improving the accuracy of welding between the third portion 103 and the joining terminal portion 85, and ultimately improving the quality of the joining portion.

[0102] 27 , the terminal holder 75 may have an enclosing portion 131 that surrounds the third portion 103 of the relay terminal 73 and the connecting terminal portion 85 of the power line bus bar 71 in an overlapping state. The enclosing portion 131 extends radially from the main body portion 121 of the terminal holder 75, and sandwiches the third portion 103 and the connecting terminal portion 85 in an overlapping state between the main body portion 121 and the enclosing portion 131.

[0103] This allows the connecting terminal portion 85 of the power line busbar 71 to be appropriately overlapped with the third portion 103 of the relay terminal 73 attached to the busbar holder 74 by the terminal holder 75, thereby improving the quality of the connecting portion between the third portion 103 of the relay terminal 73 and the connecting terminal portion 85 of the power line busbar 71.

[0104] The relay terminal 73 may have the following configuration: In the configuration shown in Fig. 28(a) , the first portion 101 and the third portion 103, which are on both sides of the second portion 102, are bent in opposite directions in the axial direction in the relay terminal 73. In this configuration, the extending direction of the third portion 103 is different from the configuration shown in Fig. 16 , etc., but the same applies in that the connecting terminal portion 85 of the power line bus bar 71 is connected and fixed to the third portion 103 by welding or the like. In other words, similar to the configuration described above, the relay terminal 73 is connected to the circuit board 55 and the connecting terminal portion 85 of the power line bus bar 71 on both sides of the second portion 102.

[0105] 28(b), the relay terminal 73 has a bent second portion 102 formed at one axial end of the first portion 101, and a third portion 103, which is a joint portion with the joint terminal portion 85 of the power line bus bar 71, extending linearly from the second portion 102. In this configuration, the direction in which the third portion 103 extends is different from the configuration of FIG. 16, etc., but the third portion 103 is the same in that the joint terminal portion 85 of the power line bus bar 71 is joined and fixed by welding or the like to the third portion 103. In other words, similar to the configurations described above, the relay terminal 73 is fixed to the circuit board 55 and the joint terminal portion 85 of the power line bus bar 71 on both sides of the second portion 102.

[0106] The first stator winding 32a and the second stator winding 32b may have the configuration shown in Fig. 29. In the first stator winding 32a shown in Fig. 29(a), U-phase partial windings U2 and U3, V-phase partial windings V1 and V4, and W-phase partial windings W2 and W3 are connected to one another at a common neutral point N1. In the second stator winding 32b shown in Fig. 29(b), X-phase partial windings X2 and X3, Y-phase partial windings Y2 and Y3, and Z-phase partial windings Z1 and Z4 are connected to one another at a common neutral point N2. In this case, it is preferable that the neutral points of each of the stator windings 32a and 32b be connected by a single neutral bus bar.

[0107] In the stator core 31, each split core 61 may have a plurality of teeth 34. For example, the split core 61 may have three teeth 34. The stator core 31 may not have a split core structure, that is, may have a structure that forms an integral ring shape that cannot be separated in the circumferential direction.

[0108] The number of teeth of the stator core 31 may be other than 18. In this case, however, the number of teeth should be 3×n. The number of poles of the rotor 40 may be other than 14.

[0109] In the above embodiment, the stator winding 32 has a first stator winding 32a and a second stator winding 32b, and is configured to have a total of six phase windings. However, this may be modified so that the stator winding 32 has a set of three phase windings.

[0110] The rotating electric machine may be an outer rotor type rotating electric machine instead of an inner rotor type rotating electric machine. In an outer rotor type rotating electric machine, the back yoke 33 is located radially inward in the stator core 31, and the teeth 34 are provided so as to extend radially outward from the back yoke 33. In this configuration, as in the above, it is preferable that the busbar module 70 is provided on the axial end side of the stator 30.

[0111] The technical ideas extracted from the above-described embodiments will be described below. [Configuration 1] A rotor (40) having a stator (30) with a multi-phase stator winding (32), a rotor (40) disposed radially opposite the stator and rotating together with a rotating shaft (11), a busbar module (70) having an annular busbar holder (74) fixed to an axial end of the stator, with a plurality of busbars (71) and a plurality of relay terminals (73) attached to the busbar holder, the busbars being provided for the respective phases of the stator winding, and a circuit board (55) provided on the opposite side of the stator in the axial direction across the busbar module, wherein the busbars and the circuit board are electrically connected by the relay terminals, and each of the relay terminals is made of an elongated conductor and has a first portion (101) extending axially and having one end fixed to the circuit board, and a second portion (102) bent radially from the other end of the first portion, and the first portion is provided with a bent-shaped stress absorbing portion (107), The rotating electric machine according to the present invention, wherein the busbar module has a holding structure that holds the relay terminals using a terminal holder (75), and the multiple relay terminals are arranged side by side in the circumferential direction and collectively fixed to the busbar holder with the second portion sandwiched between the busbar holder and the terminal holder. [Configuration 2] The rotating electric machine according to the present invention, wherein each relay terminal has, in addition to the first portion and the second portion, a third portion (103) on one side of the second portion in the longitudinal direction of the relay terminal, opposite the first portion, and the third portion is fixed to the busbar. [Configuration 3] The rotating electric machine according to the present invention, wherein the third portion of each relay terminal extends in the axial direction and is provided so as to face the first portion, and the terminal holder is attached so as to be sandwiched between the first portion and the third portion.[Configuration 4] The rotating electric machine according to Configuration 3, wherein the first portion of each relay terminal has, as the stress absorbing portion, a radially bent portion (107a) bent radially in a direction overlapping the second portion when viewed in the axial direction, and wherein, when an axial distance from a tip of the third portion to the radially bent portion in the relay terminal is L1 and an axial length in the terminal holder is L2, L1 and L2 satisfy L1 > L2. [Configuration 5] The rotating electric machine according to any of Configurations 2 to 4, wherein the terminal holder has: a main body portion (121) extending circumferentially and sandwiching the second portion of each relay terminal between itself and the busbar holder; and an engaging portion (125) extending axially from the main body portion and engageable with the busbar holder, and wherein the engaging portion engages with an engaged portion (115) on the busbar holder side, thereby fixing the terminal holder to the busbar holder. [Configuration 6] The rotating electric machine according to any one of Configurations 2 to 5, wherein the bus bar has a joining terminal portion (85) extending in the axial direction and joined to the third portion of the relay terminal in a state where the third portion is overlapped with the third portion, and the terminal holder has an alignment protrusion (122A) protruding in the radial direction and circumferentially aligning the third portion of the relay terminal with the joining terminal portion of the bus bar. [Configuration 7] The rotating electric machine according to any one of Configurations 2 to 5, wherein the bus bar has a joining terminal portion (85) extending in the axial direction and joined to the third portion of the relay terminal in a state where the third portion is overlapped with the third portion, and the terminal holder has an enclosing portion (131) that surrounds both the third portion of the relay terminal and the joining terminal portion of the bus bar in a state where the third portion of the relay terminal and the joining terminal portion of the bus bar are overlapped with each other. [Configuration 8] The rotating electric machine according to any one of Configurations 1 to 7, wherein the terminal holder has guide portions (122) interposed between the second portions of the plurality of relay terminals when the relay terminals are lined up in the circumferential direction, and a convex, easily deformable portion (124) that is deformable in a contact state is provided on at least one side of the second portions of the relay terminals and the guide portion of the terminal holder that are circumferentially opposed to each other.[Configuration 9] A rotating electric machine according to any one of Configurations 1 to 8, comprising a cylindrical housing (20) that accommodates the stator and the rotor, the housing having an end plate portion (23) located axially outward of the stator and the rotor, the end plate portion having a cylindrical bearing fixing portion (23a) in the radial center, and a bearing (26) that rotatably supports the rotating shaft fixed to the bearing fixing portion, the bearing fixing portion having an annular hollow portion (24) around it, and the hollow portion housing at least a part of the stress absorbing portion of the relay terminal.

[0112] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A rotor (40) having a stator (30) with a multi-phase stator winding (32); a rotor (40) disposed radially opposite the stator and rotating together with a rotating shaft (11); a busbar module (70) having an annular busbar holder (74) fixed to an axial end of the stator, with a plurality of busbars (71) and a plurality of relay terminals (73) attached to the busbar holder, the busbars being provided for the respective phases of the stator winding; and a circuit board (55) provided on the opposite side of the stator in the axial direction across the busbar module, wherein the busbars and the circuit board are electrically connected by the relay terminals, and each of the relay terminals is made of a long conductor and has a first portion (101) extending axially and one end of which is fixed to the circuit board, and a second portion (102) bent radially from the other end of the first portion, and the first portion is provided with a bent stress absorbing portion (107). the busbar module has a holding structure that holds the relay terminals with a terminal holder (75), and the plurality of relay terminals are arranged side by side in the circumferential direction and are collectively fixed to the busbar holder with the second portions sandwiched between the busbar holder and the terminal holder.

2. A rotating electric machine according to claim 1, wherein each of the relay terminals has, in addition to the first and second portions, a third portion (103) on either side of the second portion in the longitudinal direction of the relay terminal, opposite the first portion, and the third portion is fixed to the bus bar.

3. A rotating electric machine as described in claim 2, wherein in each relay terminal, the third portion extends in the axial direction and faces the first portion, and the terminal holder is attached in a state sandwiched between the first portion and the third portion.

4. A rotating electric machine as described in claim 3, wherein the first portion of each relay terminal has, as the stress absorbing portion, a radially bent portion (107a) bent radially in a direction overlapping the second portion when viewed from the axial direction, and when the axial distance dimension from the tip of the third portion to the radially bent portion in the relay terminal is L1 and the axial length dimension in the terminal holder is L2, L1 and L2 satisfy L1 > L2.

5. A rotating electric machine according to any one of claims 2 to 4, wherein the terminal holder has a main body portion (121) extending circumferentially and sandwiching the second portion of each relay terminal between itself and the busbar holder, and an engaging portion (125) extending axially from the main body portion and capable of engaging with the busbar holder, and wherein the terminal holder is fixed to the busbar holder by the engaging portion engaging with an engaged portion (115) on the busbar holder side.

6. A rotating electric machine as claimed in any one of claims 2 to 4, wherein the bus bar has a joining terminal portion (85) that extends in the axial direction and is joined to the third portion of the relay terminal while being overlapped with the third portion, and the terminal holder has an alignment protrusion (122A) that protrudes radially and circumferentially aligns the third portion of the relay terminal with the joining terminal portion of the bus bar.

7. A rotating electric machine as claimed in any one of claims 2 to 4, wherein the bus bar has a connecting terminal portion (85) that extends in the axial direction and is joined to the third portion of the relay terminal while overlapping the third portion, and the terminal holder has an enclosing portion (131) that surrounds both the third portion of the relay terminal and the connecting terminal portion of the bus bar while they are overlapping.

8. A rotating electric machine as described in claim 1, wherein the terminal holder has a guide portion (122) interposed between the second portions of the plurality of relay terminals when the relay terminals are lined up in the circumferential direction, and a convex, easily deformable portion (124) that can be deformed when in contact with the second portions of the relay terminals and the guide portion of the terminal holder, which are circumferentially opposed to each other, is provided on at least one side of the second portions of the relay terminals and the guide portion of the terminal holder.

9. A rotating electric machine as described in claim 1, comprising a cylindrical housing (20) that accommodates the stator and the rotor, the housing having an end plate portion (23) located axially outside the stator and the rotor, the end plate portion having a cylindrical bearing fixing portion (23a) in the radial center, a bearing (26) that rotatably supports the rotating shaft fixed to the bearing fixing portion, an annular hollow portion (24) formed around the bearing fixing portion, and at least a portion of the stress absorbing portion of the relay terminal being accommodated in the hollow portion.

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