JP5001723B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor used for driving a vehicle, and more particularly to a three-phase AC synchronous motor in which coils are connected by a bus bar.

  A vehicle in which an electric motor is mounted as a driving source of the vehicle includes an electric vehicle configured to transmit the output of the electric motor to the driving wheels using only the electric motor as a driving source, and a hybrid vehicle including both an engine and an electric motor as power sources There is. In hybrid vehicles, the generator is driven by the engine to charge the battery, and the power of the electric motor powered by the battery is transmitted to the drive wheels, and the power of both the engine and the motor can be transmitted to the drive wheels There are some types.

  As such a vehicle driving motor, a three-phase AC synchronous motor is used. This type of electric motor has a rotor having a permanent magnet and provided with a rotating shaft, and a stator having a stator core, that is, a stator core, disposed outside the rotor so as to surround the rotor. The stator core has an annular or cylindrical yoke and a plurality of teeth provided integrally therewith and projecting radially toward the central axis of rotation, and a stator winding or coil is wound around each of the teeth. Since this type of electric motor does not rotate the coil, it becomes a brushless motor that does not require a brush and a commutator, and the energization of each coil is controlled by detecting the rotational position of the rotor. Each coil is divided into three groups of U-phase, V-phase and W-phase, and each group is a single-phase alternating current having a phase of 120 degrees, and each coil is supplied with the same voltage and power. To be supplied.

  As a coil winding method, there are distributed winding in which the coil is wound around the teeth so as to cross at least three slots, and concentrated winding in which the coil is directly wound around each tooth. Since concentrated winding has the advantage that the length of the coil end protruding from the end of the stator is shortened, concentrated winding electric motors are often used for driving the vehicle.

  Since an electric motor used for driving a vehicle uses an in-vehicle battery as a power source, direct current from the battery is converted into alternating current of a predetermined cycle by an inverter, and electric power is supplied to each coil of the electric motor. The coil connection method mainly employs star connection, and one end of each concentrated coil is connected to each other via a middle point terminal, and the other end of each coil is connected to a power supply side terminal. Connected to power.

The connection of each middle point side terminal and the connection of the power supply side terminal for each group are not performed by wires, but by an annular bus bar. As the bus bar, a bus bar for connecting the middle point connected to the middle point side terminal of each coil and a three-phase portion connected to the power source side terminal of the coil in each group and electrically connected to the power source A bus bar for power connection is attached to the stator. Patent Document 1 discloses an electric motor in which a three-phase bus bar whose outer peripheral surface is coated with an insulating resin is laminated in an axial direction on an insulator attached to a stator core so as to be positioned on one end side of the stator. Patent Document 2 describes a concentrated power supply member formed into an annular shape by concentrically bundling three-phase bus bars and resin-molding them.
JP 2001-25198 A JP 2003-134724 A

  To mount three-phase bus bars stacked in the axial direction of the stator as in the conventional motor described above, the surface of the bus bar except for the terminals is made of insulating resin in order to avoid electrical connection between the bus bars. It is necessary to coat. In addition, when the bus bars for three phases are arranged concentrically, the connection terminals provided on each bus bar are connected in order to prevent electrical contact with other bus bars adjacent in the radial direction. It is necessary to provide a bent portion in the connection terminal so as to straddle other bus bars, and if the concentrated power supply member is resin-molded by bundling three-phase bus bars, an increase in size of the concentrated power supply member is inevitable.

  An object of the present invention is to provide an electric motor having a connection structure that can reliably insulate bus bars from each other with a simple structure.

  Another object of the present invention is to provide an electric motor that can be miniaturized by simplifying the connection structure.

  The electric motor of the present invention is an electric motor having a rotor having a permanent magnet and a rotating shaft, and a stator provided on the outside of the rotor and provided with a coil, and teeth integrally wound around the coil are integrally provided. A stator core formed by circularly arranging a plurality of stator segments having yoke pieces extending in the circumferential direction, an insulator having an end face wall covering the end face of the stator core, and being attached to each stator segment; A wiring support portion provided in the end face wall, and extending in the tangential direction of the yoke piece corresponding to each of the yoke pieces and formed in parallel with a plurality of straight holding grooves opened outward in the axial direction; A plurality of linear portions corresponding to the holding grooves and bent portions between the linear portions are provided, and a power supply terminal is provided on the base end side. An opening is provided between a distal end portion and the base end portion by bending a belt-shaped member, and each of the bus bars is inserted into the holding groove on the inner side. The power feeding terminal is arranged in correspondence with the opening of the bus bar outside.

  In the electric motor of the present invention, three holding grooves are formed in the wiring support portion, and the other one of the three bus bars inserted into the holding grooves, respectively, on the tip end side of two bus bars. The base end portion of the bus bar is arranged.

  The electric motor of the present invention is characterized in that the bus bar is provided with an engaging claw that engages with the inner surface of the holding groove, and the bus bar is prevented from coming off by the engagement between the engaging claw and the inner surface.

  The electric motor of the present invention is characterized in that a recess is formed at a location corresponding to the space between the yoke pieces in the bus bar.

  In the electric motor of the present invention, the bus bar inserted into the holding groove on the radially outer peripheral side has a larger cross-sectional area than the bus bar inserted into the holding groove on the radially inner peripheral side.

  In the electric motor of the present invention, the bus bar has a cross-sectional area on the distal end side larger than a proximal end side on which the power feeding terminal is provided.

  According to the present invention, the plurality of bus bars are arranged on the wiring support portion provided on the end surface wall of the insulator that covers the end surface of the stator core, and the power supply terminal of the bus bar crosses the opening of the bus bar outside the bus bar. Therefore, it is possible to arrange a plurality of power supply terminals close to each other and to electrically isolate the bus bars from each other with a simple structure without sealing the bus bars with a resin mold or the like. The motor can be reduced in size.

  The bus bar has a straight portion and a bent portion, and is an open-type polygon cut out at the opening. Therefore, the bus bar can be easily positioned with respect to the insulator, and the electric motor is configured. The manufacturing efficiency of the stator can be increased. In addition, since the bus bar has an opening, the length of the bus bar can be shortened as compared with a bus bar having a circular structure, and the material cost of the bus bar can be reduced. Furthermore, by providing the power supply terminal at the base end portion of the bus bar, the parts of the bus bar can be efficiently removed from the plate-like material, and the manufacturing cost of the bus bar can be reduced.

  By providing the engaging claw on the bus bar, it is possible to prevent the bus bar from coming off from the insulator. Therefore, it is not necessary to mold the bus bar with resin or the like, and the stator can be reduced in weight and cost. Since the recess is provided in the portion where the bus bar is exposed to the stator core through the gap of the insulator, the bus bar, the stator core and the insulation can be performed without being molded and sealed with a resin or the like. Cost reduction can be achieved.

  If a plurality of bus bars are arranged in the insulator so as to overlap in the radial direction, the length of the bus bar differs depending on the position in the radial direction, so the distance between the coil connection terminals provided on the bus bar differs depending on the bus bar. However, the electrical resistance between the coil connection terminals can be made uniform by making the cross-sectional areas of the bus bars different from each other. Moreover, the electrical resistance between the coil connection terminals can be made uniform by making the cross-sectional areas of the bus bars different according to the distance from the power supply terminal of each bus bar. Thereby, each coil voltage can be made uniform and rotation of a rotor becomes smooth.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a perspective view showing the appearance of an electric motor according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of FIG. 1, and FIG. 3 is a transverse sectional view of FIG.

  This electric motor is a three-phase AC synchronous motor that is mounted on a vehicle and used to transmit power to drive wheels, and has a housing 10 that is attached to the vehicle. As shown in FIG. 2, the housing 10 includes a housing main body 10a having a substantially cylindrical shape, and an end plate portion 10b provided integrally with one end of the housing main body 10a and closing one end of the housing main body 10a. I have. The housing body 10a is open on the opposite side to the closed end where the end plate portion 10b is provided, and a cover 10c is attached to the open end by a bolt (not shown). The open end is covered by the cover 10c. Blocked. The end plate portion 10b is continuous with the inner peripheral surface of the end portion of the housing body 10a, and a bearing mounting portion 12 that supports the bearing 11 is provided in an annular shape at the radial center of the end plate portion 10b. On the other hand, a bearing mounting portion 14 that supports the bearing 13 is provided in an annular shape at the center of the cover 10c in the radial direction, and the rotation main shaft 15 is rotatably supported at both ends by the bearings 11 and 13, respectively. The front end portion of 15 protrudes outward from the cover 10c, and the rear end portion is covered with the end plate portion 10b.

  A refrigerant passage 16 is formed in the housing main body 10a so as to open toward the closed end side and extend in the axial direction. The refrigerant passage 16 is closed on the end side of the housing main body 10a on the cover 10c side. An annular passage cover 17 that covers the opening end of the refrigerant passage 16 in a band shape is attached to the end surface of the housing body 10a. The passage cover 17 includes a refrigerant inlet 18 and a refrigerant outlet 19 as shown in FIG. Are installed next to each other, and the coolant flowing in from the refrigerant inlet 18 flows through the refrigerant passage 16 to cool the electric motor and then is discharged from the refrigerant outlet 19.

  As shown in FIG. 2, the housing 10 is formed by a housing main body 10a and a cover 10c in which end plate portions 10b are integrated. However, the structure of the housing 10 is not limited to this, and a cylindrical housing There is a type in which covers are attached to both end faces of the main body 10a. In that case, a cover in which the end plate portion 10b and the passage cover 17 shown in FIG. 2 are integrated is attached to the right end surface of the housing body 10a.

  As shown in FIG. 3, the rotary spindle 15 is provided with a rotor 21, and the rotor 21 is provided with eight permanent magnets, that is, magnets 22. This motor is an eight-pole three-phase AC motor. . However, if ten permanent magnets are provided on the rotor 21, a 10-pole motor is obtained. A substantially cylindrical stator or stator 23 is attached to the interior of the housing main body 10a so as to cover the outer peripheral surface of the rotor 21, and the stator 23 is a fixed iron core or stator core formed by laminating electromagnetic steel plates. 24.

  As shown in FIG. 3, the stator core 24 is formed by twelve stator segments 25, and one stator segment 25 has a yoke piece 26 extending in the circumferential direction and a transverse direction toward the rotation main shaft 15 with respect to the yoke piece 26. It is formed by laminating a core sheet made of a substantially T-shaped steel plate having a tooth 27 protruding and integrated with the yoke piece 26. The stator segment 25 formed by laminating a predetermined number of core sheets has an axial dimension indicated by a symbol M in FIG. The stator core 24 is formed by abutting twelve stator segments 25 at the abutting surfaces on both sides in the circumferential direction of the respective yoke pieces 26 and arranging the yoke pieces 26 in a circular shape. The yoke 28 is formed.

  As shown in FIG. 3, a convex portion 29a is provided on one end surface in the circumferential direction of the yoke piece 26, and a concave portion 29b is provided on the other end surface. Therefore, each stator segment 25 assembled in a block shape by laminating a predetermined number of core sheets manufactured by pressing into a substantially T-shape is circular by fitting the convex portions 29a and concave portions 29b of the yoke pieces 26 together. A stator core 24 having a yoke 28 is formed.

  4 is an enlarged front view showing the left end surface of the stator core in FIG. 2, FIG. 5 (A) is a front view showing one coil assembly, and FIG. 5 (B) is a right side view of FIG. 5 (A). 6 is an exploded perspective view showing the insulator, FIG. 7 is a perspective view showing a resin spacer mounted between the coil assemblies, and FIG. 8A is a view taken along line 8A- in FIG. It is an expanded sectional view which follows an 8A line, (B) is a sectional view showing the same portion as (A) in a modification of a stator, and FIG. 9 is an expanded sectional view which meets a 9-9 line in FIG. .

  As shown in FIG. 5, a bobbin-shaped insulator 31 is attached to each stator segment 25, and a coil 32 is wound around the outside of the tooth 27 via the insulator 31 to form one coil assembly 33. As shown in FIG. 4, this electric motor has twelve coil assemblies 33, and when assembling the stator 23 with these coil assemblies 33, the end surfaces of the yoke pieces 26 of the coil assembly 33 are brought into contact with each other. In addition, the convex portions 29a and the concave portions 29b of the yoke pieces 26 adjacent in the circumferential direction are fitted together. Since this electric motor has twelve coil assemblies 33 and the stator core 24 has twelve teeth 27, this motor has twelve slots. However, the number of slots is not limited to this, and the number of coil assemblies 33, that is, the number of teeth 27, is selected according to the required output characteristics, etc., so that the number of slots is set to other slots such as 18 slots and 24 slots. can do.

  As shown in FIG. 6, the insulator 31 is composed of two insulator halves 31a and 31b which are each formed of resin. One insulator half 31a is attached from one end of the stator segment 25 in the axial direction, from the left end in FIG. 2, and the other insulator half 31b is the end of the stator segment 25 in the other axial direction, In FIG. 2, it is mounted from the right end. As shown in FIGS. 2 and 6, the insulator halves 31 a and 31 b include end face walls 34 a and 34 b that cover the end faces of the stator segment 25, and side wall walls 35 a and 35 b that cover both circumferential sides of the teeth 27. Have. Outer flanges 36a and 36b that are substantially perpendicular to each of the side walls 35a and 35b and partially cover the inner surface of the yoke piece 26 are integrally connected.

  The end face walls 34 a and 34 b are respectively provided with wiring support portions 37 a and 37 b protruding in the axial direction, and the wiring support portions 37 a and 37 b correspond to the positions of the yoke pieces 26 of the stator segment 25. Further, in each of the insulator halves 31a and 31b, inner flanges 38a and 38b are integrally connected to the radially inner portions of the end face walls 34a and 34b and the side walls 35a and 35b. A pair of bobbin-like insulators 31 is formed by the two insulator halves 31a and 31b having such a shape. Since the stator core 24 is formed by twelve stator segments 25, the stator core 24 has twelve insulators 31.

  A coil 32 is directly wound around the outside of the tooth 27 via the insulator halves 31a and 31b with the insulator halves 31a and 31b attached to the respective stator segments 25 from both ends, as shown in FIG. Thus, one coil assembly 33 is formed. Thus, each coil assembly 33 is formed by winding the coil 32 through the insulator 31 around the teeth 27 of each stator segment 25 in a state where the stator core 24 is divided into a plurality of stator segments 25. Therefore, this electric motor becomes a split core type concentrated winding. By fitting the twelve coil assemblies 33 with the convex portions 29 a and the concave portions 29 b at both ends of the yoke piece 26, a circular yoke 28 is formed by all the yoke pieces 26. When the yoke pieces 26 are welded and joined together while the yoke pieces 26 are in contact with each other at the abutting surface, a circular yoke 28 in which all the yoke pieces 26 are integrated is formed.

  As shown in FIGS. 5 and 6, three holding grooves 41 to 43 are formed in parallel with each other in the wiring support portion 37a of one insulator half 31a. Each of the holding grooves 41 to 43 is a linear groove extending straight in the tangential direction of the yoke piece 26, that is, in a direction perpendicular to the radial line of the rotation center axis of the rotor 21. Thereby, the polygonal holding grooves 41 to 43 in which the portions between the respective wiring support portions 37 a are corner portions are formed concentrically and in parallel by the linear grooves formed in the twelve insulators 31. One holding groove 44 is formed in the wiring support portion 37 b of the other insulator half 31 b corresponding to the radial position of the holding groove 43. Similarly to the other holding grooves 41 to 43, the holding groove 44 is a straight groove extending straight in the tangential direction of the yoke piece 26, and each of the holding grooves 44 is formed by twelve straight grooves formed in the 12 insulators 31. A polygonal holding groove 44 having a corner portion between the wiring support portions 37b is formed. In the illustrated case, since the number of coils 32 is twelve, a regular dodecagonal holding groove is formed entirely by the holding grooves 41 to 44 formed by all the insulators 31.

  Between the wiring support portions 37a adjacent to each other in the circumferential direction, spacers 45a for resin corners shown in FIG. 7 are incorporated. As shown in FIG. 7, the spacer 45 a has four partition walls 46 to 49 that are bent and extended in the circumferential direction and are provided with thin wall portions at both ends in the circumferential direction. Three holding grooves 41 to 43 communicating with the holding grooves 41 to 43 are formed. The spacer 45a is incorporated between the wiring support portions 37a of the coil assembly 33 so that the thin-walled portion overlaps the circumferential end portion of the wiring support portion 37a.

  FIG. 10 is an exploded perspective view showing a stator and a bus bar for connecting a power source, and shows a state where a coil is removed. FIG. 11 is a perspective view showing a bus bar for midpoint connection, and FIG. 12 is a front view showing a state in which three bus bars for power supply connection are arranged concentrically, and FIGS. ) Is a developed view of a bus bar for power connection, FIG. 13D is a cross-sectional view taken along line 13D-13D in FIG. 13A, and FIG. 14 is a connection diagram of coils.

  As shown in FIG. 10, when the spacer 45a is incorporated between the respective wiring support portions 37a, an annular portion that supports the wiring is formed by the wiring support portion 37a including the spacer 45a to form a dodecagon as a whole. The As shown in FIG. 10, a spacer 45b is incorporated between the wiring support portions 37b of the insulator half 31b, and the spacer 45b corresponds to the holding groove 44 of the wiring support portion 37b. A holding groove communicating with this is formed. However, the spacer 45a portion may be formed integrally with the wiring support portion 37a, and the spacer support portion 37b may also be formed integrally with the wiring support portion 37b.

  Bus bars 51 to 53 for power supply connection are inserted into the holding grooves 41 to 43, respectively, and a bus bar 54 for connecting the middle point is inserted into the holding groove 44. In FIG. 5, one end portion of the coil 32 is a power supply side terminal 32a, and the other end portion is a midpoint side terminal 32b. The terminals 32a and 32b are shown in an extended state. However, both ends are bent so that the power supply side terminal 32a is connected to one of the three power supply side bus bars 51 to 53, and the midpoint side terminal 32b is connected to the midpoint connection bus bar 54. .

  Each of the bus bars 51 to 54 is formed by bending a belt-like member having a predetermined length made of a metal such as a copper alloy, and a plurality of linear portions inserted into the holding grooves 41 to 44 of the wiring support portions 37a and 37b, respectively. And a plurality of bent portions between the straight portions, and the bent portions are inserted into the holding grooves 41 to 44 of the spacers 45a and 45b. As shown in FIGS. 10 and 12, the bus bar 51 inserted into the radially outermost holding groove 41 among the three holding grooves 41 to 43 formed in parallel to the wiring support portion 37a is for the W phase. The base end portion is provided with a power supply terminal 51w and four coil connection terminals 51c connected to the power supply side terminal 32a of the coil 32 are provided at predetermined intervals. The bus bar 53 inserted into the innermost holding groove 43 among the three holding grooves 41 to 43 is for the V phase, and a power supply terminal 53v is provided at the base end portion thereof, and the power supply side terminal 32a of the coil 32 is provided. Four coil connection terminals 53c are provided at predetermined intervals. Similarly, at the base end portion of the U-phase bus bar 52 inserted into the intermediate holding groove 42, a power supply terminal 52u is provided, and a coil connection terminal 52c connected to the power supply side terminal 32a of the coil 32 has a predetermined value. Four are provided for each interval.

  The midpoint connection bus bar 54 shown in FIG. 11 is inserted into the holding groove 44 formed in the wiring support portion 37b, and 12 bus bars 54 connected to the midpoint side terminal 32b of the coil 32, respectively. A coil connection terminal 54c is provided and is a regular dodecagon.

  Each of the bus bars 51 to 54 has a rectangular cross-sectional shape and is inserted into the holding grooves 41 to 44 so that the long side thereof is parallel to the rotation main shaft 15. As shown in FIG. 8A, the bus bars 51 to 53 for connecting the power supply are arranged on one end side of the stator core 24 corresponding to the yoke 28, and the bus bar 54 for connecting the midpoint is on the other end side of the stator core 24. Since it is arranged corresponding to the yoke 28, the radial dimension of the stator core 24 can be shortened compared to the case where all the bus bars 51 to 54 are arranged on one end side of the stator core 24, It becomes possible to reduce the size of the electric motor.

  Moreover, since the respective wiring support portions 37 a and 37 b are provided corresponding to the positions of the yoke pieces 26 of the stator segment 25, the wiring support portions 37 a and 37 b into which the bus bars 51 to 54 are inserted are the inner periphery of the stator core 24. It doesn't push inward from the face. Thereby, when the rotor 21 is incorporated in the stator core 24, interference between the wiring support portions 37a and 37b and the rotor 21 can be avoided. Therefore, when the rotor 21 is assembled from the left side of the stator core 24 in FIG. 2, the rotor 21 does not interfere with the wiring support portion 37a. In particular, as described above, in an electric motor having a housing of a type in which covers are attached to both ends of a cylindrical housing body, the rotor 21 is inserted into the stator core 24 from either the left side or the right side in FIG. However, it can be incorporated without interfering with the wiring support portions 37a and 37b.

  As described above, the power connection bus bars 51 to 53 are inserted into the three holding grooves 41 to 43 of the wiring support portion 37a, and the midpoint connection bus bar 54 is inserted into the holding grooves 44 of the wiring support portion 37b. However, as a form of the stator 23, there is a type in which the bus bar 54 for connecting the middle point is inserted into one of the three holding grooves 41 to 43 of the wiring support portion 37a. In that case, two of the three power supply connection bus bars 51 to 53 and the midpoint connection bus bar 54 are inserted into the holding grooves 41 to 43 formed in the wiring support portion 37a, and the other 1 One bus bar is inserted into the holding groove 44 of the wiring support portion 37b.

  FIG. 8B is a cross-sectional view showing a modified example of the stator 23. In this type of stator 23, two holding grooves 41 and 42 are formed in the wiring support portion 37a. The holding grooves 43 and 44 are formed. Therefore, any two of the four bus bars 51 to 54 are inserted into the holding grooves 41 and 42 of the wiring support portion 37a, and any other two are inserted into the holding grooves 43 and 44 of the wiring support portion 37b. Become. Thus, if two holding grooves are formed at both ends of the stator segment 25, the radial dimension of the stator core 24 can be made shorter than in the case of FIG. 8A, and the electric motor can be further downsized. Can do.

  As shown in FIG. 13, power supply connection bus bars 51 to 53 are provided with power supply terminals 51w, 52u, and 53v on the base end side, respectively, and are formed into shapes as shown by pressing a metal plate. It is punched and processed into the shape shown in FIG. 10 by bending at the portion indicated by the broken line and curving the portion of the coil connection terminal. In this way, since the power supply terminals 51w, 52u, 53v are provided at the base end portions of the power connection bus bars 51-53, the power supply terminals 51w, 52u, 53v are provided at the center in the longitudinal direction. Compared with the case where it provides, when taking parts from a metal plate by press work, each bus-bar 51-53 can be efficiently manufactured with a sufficient yield by reducing a scrap part.

  As shown in FIGS. 10 and 12, the three power supply bus bars 51 to 53 are provided with openings between the base end portion where the power supply terminals 51 w, 52 u and 53 v are provided and the tip end portion, respectively. Thus, the power supply terminals 51w, 52u and 53v are inserted into the holding grooves 41 to 43 so as to be adjacent to each other, instead of the closed type connected in a ring shape. The bus bar 51 inserted into the outermost holding groove 41 and the bus bar 53 inserted into the innermost holding groove 43 have their distal ends adjacent to each other in the radial direction from the base end toward the distal end. In FIG. 10, it extends counterclockwise. On the other hand, the bus bar 52 inserted into the intermediate holding groove 42 extends in the clockwise direction from the proximal end portion toward the distal end portion, and the distal end portion of the bus bar 52 is the proximal end of the other two bus bars 51 and 53. It is the club side.

  The bus bar 52 inserted into the holding groove 42 on the inner side of the holding groove 41 is made to correspond to the opening portion so that the power supply terminal 52u crosses the opening portion of the bus bar 51 radially outside the radial direction. It is arranged in the holding groove 42. Similarly, the bus bar 53 inserted into the holding groove 43 on the inner side of the holding grooves 41 and 42 has its power supply terminal 53v radially across the opening of the bus bars 51 and 52 radially outward. The holding grooves 43 are arranged so as to correspond to the respective openings. Accordingly, since the two bus bars 52 and 53 located inside the bus bar 51 extend in the radial direction so as not to straddle the radially outer bus bars, the bus bars 51 to 53 are sealed with resin molds. Without stopping, mutual electrical connection can be avoided, and insulation can be provided with a simple structure. And since each bus bar 51-54 has a linear part and a bending part corresponding to the polygonal holding grooves 41-44, when inserting the bus bars 51-54 in the holding grooves 41-44, respectively. Positioning with respect to the insulator 31 can be easily performed, and the assembly efficiency can be increased. Furthermore, since the bus bars 51 to 54 do not have an arc portion, the length can be shortened as compared with the case where each of the bus bars 51 to 54 is circular, and the material cost of the bus bars 51 to 54 is reduced. be able to. Furthermore, since the bus bars 51 to 53 are not ring-shaped but are of an open type provided with openings, the material cost can be reduced as compared with the case where each of the bus bars 51 to 53 is a closed type. it can. Thus, since the material cost of the bus bars 51-54 can be reduced, the manufacturing cost of the stator 23 can be reduced.

  As shown in FIGS. 10 and 12, the bus bar 52 inserted into the intermediate holding groove 42 is arranged so that the distal end thereof is on the base end side of the other bus bars 51, 53. The bus bars 51 to 53 may be extended in the clockwise direction or the counterclockwise direction from the proximal end part to the distal end part so that the distal ends thereof are aligned in the radial direction. Also, the power supply terminal of the radially inner bus bar crosses the opening of the outer bus bar in the radial direction.

  Each bus bar 51 to 54 is provided with an engaging claw 55. The engaging claw 55 forms a U-shaped slit in the bus bars 51 to 54 and is bent so that the front end of the engaging claw 55 protrudes from the surface of the bus bars 51 to 54 as shown in FIG. The front end of the engaging claw 55 faces the side where the coil connection terminals 51c to 54c of the respective bus bars 51 to 54 are provided. Therefore, when the respective bus bars 51 to 54 are inserted into the holding grooves 41 to 44, the engaging claws 55 are elastically engaged with the inner surfaces of the holding grooves 41 to 44, and the bus bars 51 to 54 come out of the holding grooves 41 to 44. Can be prevented. As a result, the bus bars 51 to 54 can be prevented from coming off without covering the bus bars 51 to 54 with the resin mold, and the weight and cost of the stator 23 can be reduced. As shown in FIG. 13, the engaging claws 55 are provided in the respective straight portions of the bus bars 51 to 54, but the number of the engaging claws 55 formed on the bus bars 51 to 54 may be an arbitrary number. it can.

  As shown in FIG. 9, the portion corresponding to the abutting portion between the yoke pieces 26 of the stator core 24 corresponds to the gap of the insulator 31 and is not covered by the insulator 31, and each bus bar 51 to 54 includes There is a portion exposed at the end face of the stator core 24. Each bus bar 51-54 is formed with a recess 56 corresponding to the abutting portion of each yoke piece 26, and the distance D1 between the yoke piece 26 and the recess 56 of each bus bar 51-54 is different from that of the other bus bar 51-54. It is set larger than the interval D0 between the portions. Thereby, the insulation of the part exposed to the end surface of the stator core 24 through the clearance gap of the insulator 31 is performed reliably.

  As shown in FIG. 13, when the lengths of the respective bus bars 51 to 53 are L1 to L3, the bus bars inserted into the radially outer holding grooves are longer than the bus bars inserted into the inner holding grooves. Become. That is, the length is L1> L2> L3. Moreover, the distance between the coil connection terminals 51c to 53c provided on the respective bus bars 51 to 53 is different depending on the bus bars 51 to 53, and the distance between the coil connection terminals 51c to 53c in the radially outer bus bar is different. The distance is longer than the distance between the terminals on the inner bus bar. For example, the distance between the coil connection terminals 51c is longer than the distance between the coil connection terminals 52c. Therefore, the cross-sectional area of the outer peripheral bus bar is set to be larger than the cross-sectional area of the inner peripheral bus bar. For example, if the width dimensions of the respective bus bars 51 to 53 are B1 to B3 as shown in FIG. 13, the respective width dimensions are set to B1> B2> B3. Thereby, the electrical resistance between the coils can be made uniform, and the rotation main shaft 15 can be smoothly rotated. As shown in FIG. 13, the width dimensions B1 to B3 are made different by the bus bars 51 to 53 in order to make the electric resistance uniform between the coils 32, but the cross sectional areas are made different by making the thickness dimensions different. be able to.

  Each of the bus bars 51 to 53 is formed by bending a belt-like member having a predetermined length, and power supply terminals 51w, 52u, and 53v are provided at the respective base ends, and the respective coil connection terminals 51c to 53c are The distance from the base end will be different. Therefore, as shown in FIG. 14, the four coils 32 connected to the coil connection terminal 51c of the bus bar 51 are different in distance from the power supply terminal 51w, and the same applies to the other bus bars 52 and 53. . Therefore, the cross-sectional areas of the respective bus bars 51 to 53 are made different according to the distances from the power supply terminals 51w, 52u, 53v, and the cross-sectional area on the distal end side away from the power supply terminals is larger than the cross-sectional area on the base end side. Is set. For example, if the width dimensions according to the position of the bus bar 51 in the longitudinal direction are B1a to B1c, B1a <B1b <B1c is set. Similarly, the bus bar 52 is also set to B2a <B2b <B2c, and the bus bar 53 is also set to B3a <B3b <B3c. Thereby, even if the distance from the power supply terminals 51w, 52u, and 53v of the coil connection terminals 51c to 53c connected to the bus bars 51 to 53 is different, the electric resistance between the coils and the power supply terminals is made uniform. The rotation main shaft 15 can be smoothly rotated. As shown in FIG. 13, the width dimensions of the bus bars 51 to 53 are made different from the base end portion toward the tip end portion in order to make the electric resistance uniform between the coils 32, but the thickness dimensions are made different. The cross-sectional area can be made different also by.

  The electric motor described above is mounted on an electric vehicle and used as a drive source for the vehicle, but can also be used as an electric motor for a hybrid vehicle mounted on the vehicle together with the engine. Thus, when the electric motor is used for driving a vehicle, the direct current of the in-vehicle battery is converted into alternating current of a predetermined frequency by an inverter, and electric power is supplied to each coil 32 constituting the U phase, the V phase, and the W phase. Is supplied. An electric motor mounted on an electric vehicle or a hybrid vehicle not only drives the vehicle by power from a power source such as a battery, but also recovers regenerative energy during vehicle braking, or is driven by an engine to charge the battery. Therefore, it has a function as a generator. When functioning as a generator, the generated alternating current is converted into direct current by an inverter and charged to the battery.

  As shown in FIG. 1, the power supply terminals 51w, 52u, and 53v for power connection are connected to connection terminals 61 to 63 attached to the outside of the housing 10, and the connection terminals 61 to 63 are illustrated. Not to be connected to the inverter via a cable. An output terminal 64 of the temperature sensor is provided in the housing 10 adjacent to these connection terminals 61 to 63, and a detection signal of the temperature sensor for detecting the temperature of the refrigerant flowing through the refrigerant passage 16 is illustrated via the output terminal 64. Not sent to the control unit. As shown in FIG. 2, a resolver 65 for detecting the rotation angle of the rotary spindle 15 is provided in the housing 10, and an output terminal 66 of a signal line connected to the resolver 65 is an end plate as shown in FIG. It is attached to the outer surface of the part 10b. Based on the signal from the resolver 65, the rotational position of the rotor 21 is detected, and the control unit controls the switching of current to the U-phase, V-phase, and W-phase coils 32. Therefore, this electric motor is a brushless electric motor.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although the above-described electric motor is applied to an electric vehicle, the electric motor can also be applied to a hybrid vehicle including both an electric motor and an engine as power sources.

It is a perspective view showing the appearance of the electric motor which is one embodiment of the present invention. It is a longitudinal cross-sectional view of FIG. It is a cross-sectional view of FIG. It is an enlarged front view which shows the left end surface in FIG. 2 of a stator. (A) is a front view which shows one coil assembly, (B) is a right view of (A). It is a disassembled perspective view which shows an insulator. It is a perspective view which shows the resin-made spacers mounted between coil assemblies. (A) is an expanded sectional view which follows the 8A-8A line in FIG. 4, (B) is sectional drawing which shows the part similar to (A) in the modification of a stator. It is an expanded sectional view which follows the 9-9 line in FIG. It is a disassembled perspective view which shows the bus bar for a stator core and a power supply connection. It is a perspective view which shows the bus bar for midpoint connection. It is a front view which shows the state by which the bus bar for three power connection is arrange | positioned concentrically. (A)-(C) are the expanded views which show the bus bar for power supply connection, (D) is an expanded sectional view which follows the 13D-13D line | wire in (A). It is a connection diagram of a coil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Housing 10a Housing main body 15 Rotation main shaft 21 Rotor 23 Stator 24 Stator core 25 Stator segment 26 Yoke piece 27 Teeth 28 Yoke 31 Insulator 32 Coil 32a Power supply side terminal 32b Middle point side terminal 33 Coil assemblies 34a, 34b End face walls 37a, 37b Wiring Support portions 41 to 44 Holding grooves 45a and 45b Spacers 51 to 54 Bus bars 51c to 53c Coil connection terminals 51w, 52u, and 53v Feeding terminals 55 Engaging claws 56 Recesses

Claims (6)

1. An electric motor having a rotor having a permanent magnet and a rotating shaft; and a stator disposed outside the rotor and provided with a coil;
   A stator core formed by arranging a plurality of stator segments in a circular shape, each having a yoke piece that is integrally provided with teeth around which the coil is wound and extends in the circumferential direction;
   An insulator having an end face wall covering an end face of the stator core, and mounted on each stator segment;
   A wiring support portion provided in the end face wall, and extending in the tangential direction of the yoke piece corresponding to each of the yoke pieces and formed in parallel with a plurality of straight holding grooves opened outward in the axial direction;
   A plurality of linear portions corresponding to the holding grooves and bent portions between the linear portions are provided, and a belt-like member provided with a power supply terminal on the base end side is bent to form a distal end portion and the base end portion. There are a plurality of bus bars each provided with an opening, each inserted into the holding groove,
   An electric motor, wherein the power supply terminal of the bus bar inserted into the holding groove on the inner side is arranged in correspondence with the opening of the outer bus bar.
2.   2. The electric motor according to claim 1, wherein three holding grooves are formed in the wiring support portion, and one of the three bus bars inserted into the holding groove, respectively, on the tip end side of the two bus bars. An electric motor comprising a base end portion of the bus bar.
3.   3. The electric motor according to claim 1, wherein an engagement claw that engages with an inner surface of the holding groove is provided on the bus bar, and the bus bar is prevented from coming off by engagement between the engagement claw and the inner surface. Electric motor.
4.   The electric motor according to any one of claims 1 to 3, wherein a recess is formed in a portion of the bus bar corresponding to the space between the yoke pieces.
5.   5. The electric motor according to claim 1, wherein the bus bar inserted into the holding groove on the radially outer peripheral side is disconnected from the bus bar inserted into the holding groove on the radially inner peripheral side. An electric motor characterized by a large area.
6.   The electric motor according to any one of claims 1 to 5, wherein the bus bar has a larger cross-sectional area on a distal end side than on a proximal end side on which the power feeding terminal is provided.

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