JP2022054858A - Stator-coil assembly and electric motor including the same - Google Patents

Abstract

To increase the productivity of an electric motor by reducing the number of contacts between a coil and a bus bar.SOLUTION: The stator-coil assembly 2 includes a stator core 10 having a plurality of teeth 12 provided spaced circumferentially apart and a coil 30 wound around each of the teeth 12. The coils 30 in the same phase adjacent to each other are formed by one continuous coil wire.SELECTED DRAWING: Figure 2

Description

The present invention relates to a stator-coil assembly and an electric motor comprising the stator-coil assembly.

For example, in the electric motor shown in Patent Document 1 below, a plurality of coils are formed by one continuous coil wire (conductor).

Japanese Unexamined Patent Publication No. 2019-97309

In the above electric motor, since other coils having different phases are arranged between the coils having the same phase formed by one coil wire, the crossover wire connecting the coils having the same phase is the other coil. It is provided across the. In this case, since the crossover connecting the coils of each phase (U phase, V phase, W phase) is provided on one side in the axial direction of the stator core, the crossover wire of each phase is arranged on one side in the axial direction of the stator core. Space is required for this, and the axial dimension of the electric motor increases.

For example, if each coil is formed of a separate coil wire and both ends of each coil are connected to the bus bar, the crossover wire connecting the coils is not required, so that the axial dimension of the electric motor can be reduced. However, if both ends of each coil are connected to the bus bar in this way, the number of contacts between the coil and the bus bar increases, and the productivity decreases.

Therefore, an object of the present invention is to reduce the contact points between the coil and the bus bar to increase the productivity of the electric motor.

In order to solve the above problems, the present invention is a stator-coil assembly of an electric motor having a stator core having a plurality of teeth provided apart from each other in the circumferential direction and a coil wound around each tooth. In-phase coils adjacent to each other provide a stator-coil assembly formed by a single continuous coil wire.

As described above, in the present invention, coils having the same phase adjacent to each other are formed by one continuous coil wire. As a result, the number of contacts between the coil and the bus bar can be reduced as compared with the case where both ends of each coil are connected to the bus bar (that is, when the number of contacts is twice the number of coils).

In the above-mentioned stator-coil assembly, the coil wires are continuously wound around the adjacent teeth provided on the stator core to form coils having the same phase adjacent to each other. Specifically, after winding the coil wire around one of the adjacent teeth, the coil wire is wound around the other of the adjacent teeth while maintaining the tension of the coil wire. At this time, the adjacent coils are pulled toward each other by the tension of the crossover. The teeth of the stator core are arranged in a radial pattern, and the distance between the adjacent teeth becomes smaller toward the inner diameter side. There is a risk of shifting.

Therefore, a locking portion is provided in the insulator arranged between the stator core and the coil, and among the coil wires forming adjacent coils of the same phase, the crossover wire connecting the coils is outside the locking portion of the insulator. It is preferable to engage from the radial side. In this way, by engaging the crossover wire connecting the coils with the locking portion of the insulator from the outer diameter side, both coils can be pulled toward the outer diameter side via the crossover wire, so that each coil has an inner diameter. It is possible to prevent it from shifting to the side.

The above electric motor can form a plurality of coil sets composed of coils having the same phase adjacent to each other. In this case, if contacts with the bus bar are provided at both ends of the coil wire of each coil set, the number of contacts can be halved as compared with the case where both ends of all the coils are connected to the bus bar.

The above electric motor forms a plurality of coil sets consisting of coils having the same phase adjacent to each other, and the coil sets having the same phase are provided so as to be spaced apart from each other in the circumferential direction with the coil sets having different phases interposed therebetween. be able to. In this case, if a coil set having the same phase separated in the circumferential direction is formed by one continuous coil wire and contacts with a bus bar are provided at both ends of the coil wire, both ends of the coil wire of each coil set are bus bars. The number of contacts between the coil wire and the bus bar can be further reduced compared to the case of connecting to. At this time, if a contact with the feeder line is provided on the crossover wire connecting the coil sets having the same phase separated in the circumferential direction, a circuit in which both coil sets are arranged in parallel can be formed.

As described above, according to the present invention, since the contact points between the coil wire and the bus bar are reduced, the productivity of the stator-coil assembly and the productivity of the electric motor can be improved.

It is sectional drawing of an electric motor. It is a perspective view of the stator coil assembly which concerns on one Embodiment of this invention. It is a side view which looked at the said stator-coil assembly from the outer diameter side. It is a front view which looked at the stator-coil assembly from the axial direction. FIG. 3 is a cross-sectional view taken along the line XX of FIG. It is a circuit diagram which shows the connection state of each coil of the said stator-coil assembly. It is sectional drawing of the stator coil assembly which concerns on other embodiment. It is a circuit diagram which shows the connection state of each coil of the stator-coil assembly of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The electric motor 1 shown in FIG. 1 is a three-phase DC brushless motor, and mainly includes a stator-coil assembly 2, a rotor 3, a rotating shaft 4, a bus bar 5, and a housing 6 according to an embodiment of the present invention. Be prepared. The stator-coil assembly 2 is fixed to the inner peripheral surface of the housing 6. The rotary shaft 4 is rotatably attached to the housing 6 via the bearing 7. The rotor 3 has a rotor core fixed to the rotating shaft 4 and a magnet fixed to the outer periphery of the rotor core. By controlling the current supplied from the external power supply by the inverter circuit and supplying it to the stator-coil assembly 2, the rotor 3 and the rotating shaft 4 rotate integrally. In this electric motor 1, when the number of magnetic poles of the rotor 3 is P and the number of grooves between teeth in the stator-coil assembly 2 is N, P: N is other than 2: 3 (that is, 2N / 3P is). It is a fractional groove motor (not an integer), specifically, a 10-pole 12-groove fractional groove motor having a P: N of 10:12. Other fractional groove motors include 8-pole 9-grooves and 14-pole 18-grooves.

As shown in FIGS. 2-4, the stator-coil assembly 2 has a stator core 10, an insulator 20, and a coil 30.

As shown in FIG. 5, the stator core 10 has a cylindrical portion 11 and a plurality of teeth 12 protruding from the cylindrical portion 11 in the inner diameter direction. The stator core 10 is integrally formed of, for example, a laminated steel sheet made of a laminated body of electromagnetic steel sheets coated with an insulating film or a powder magnetic core made of a green compact of soft magnetic powder coated with an insulating film. The teeth 12 are arranged at a plurality of locations (12 locations in the illustrated example) at equal intervals in the circumferential direction. In the illustrated example, a flange portion 12a is provided at the inner diameter end of each tooth 12.

The insulator 20 is a resin component that is arranged between the stator core 10 and the coil 30 and insulates them from each other. The insulator 20 of the present embodiment has a tubular tooth covering portion 21 that covers each tooth 12 of the stator core 10, a circumferential portion 22 that is continuous with the outer diameter end of each tooth covering portion 21 in the circumferential direction, and each tooth covering. It has an annular portion 23 (see FIG. 4) provided at one end of the portion 21 in the axial direction. The insulator 20 is formed of, for example, two parts divided at the central portion in the axial direction, and is mounted on the stator core 10 from both sides in the axial direction. In addition, the stator core 10 may be integrally formed by injection molding with a resin as an insert component.

The coil 30 is composed of a coil wire wound around the outer circumference of each tooth 12 of the stator core 10 by concentrated winding (see FIG. 5). The coil wire consists of a conductor wire (for example, a copper wire) coated with an insulating material such as enamel. All the coils 30 are in phase with the coils 30 adjacent to each other in the circumferential direction, and the coil set 40 is formed by a pair of adjacent coils 30 having the same phase. In the present embodiment, as shown in FIG. 4, the first U-phase coil set 40 (U1), the second U-phase coil set 40 (U2), the first V-phase coil set 40 (V1), and the second The V-phase coil set 40 (V2), the first W-phase coil set 40 (W1), and the second W-phase coil set 40 (W2) are provided.

Each coil set 40 is formed of one continuous coil wire. Specifically, to explain with the first U-phase coil set 40 (U1) shown at the right end of FIG. 6, the coil wire is wound in the positive direction (clockwise direction) around the teeth 12 on the right side of the drawing, and one coil 30 is used. The coil set 40 is formed by winding the coil wire around the tooth 12 on the left side in the drawing in the opposite direction (counterclockwise direction) to continuously form the other coil 30. Both ends of the coil wire of each coil set 40 thus formed are connected to the conductor of the bus bar 5 (see FIG. 1). Specifically, both ends of the coil wire of each coil set 40 are attached in a state where the conductor of the bus bar 5 can be energized by fusing or the like, and these contacts P are provided. The arrow on the coil wire in FIG. 6 indicates the winding direction and order of the coil wire.

In this embodiment, the coil wires of each coil set 40 are connected by a star connection. Specifically, one end of the coil wire of each coil set 40 is connected to the neutral wire 5a of the bus bar 5, and the other end of the coil wire of each coil set 40 is connected to the connection terminal 5b of the bus bar 5. Connected to the connected conductor. As a result, the first U-phase coil set 40 (U1) and the second U-phase coil set 40 (U2), the first V-phase coil set 40 (V1) and the second V-phase coil set 40 (V2) , The first W-phase coil set 40 (W1) and the second W-phase coil set 40 (W2) are connected in parallel, respectively. A feeder from an external power source is connected to the connection terminal 5b of the bus bar 5.

In this way, by forming the adjacent coils 30 having the same phase with one continuous coil wire, the contact point P between the coil wire and the bus bar 5 is compared with the case where each coil 30 is formed with a separate coil wire. Since the number of (fusing points) can be reduced, the productivity of the stator-coil assembly 2 is improved, and the productivity of the electric motor 1 is improved.

The coil wire has a portion forming adjacent coils 30 having the same phase and a crossover wire 31 connecting both coils 30. Since it is necessary to apply a certain amount of tension to the coil wires when forming each coil 30, tension is also applied to the crossover wire 31 connecting the coils 30 to each other, and both coils 30 are pulled toward each other. However, since all of the adjacent teeth 12 extend toward the axial center, if both coils 30 are pulled to the side where they approach each other, there is a possibility that both coils 30 are displaced to the side where the distance between the teeth 12 is narrow, that is, to the inner diameter side. be.

Therefore, in the present embodiment, the insulator 20 is provided with a locking portion 24, and the crossover wire 31 is engaged with the locking portion 24 from the outer diameter side. Specifically, as shown in FIGS. 2 to 4, a plurality of annular portions 23 provided at one end of the insulator 20 in the axial direction (left side in FIG. 3) are engaged with each other so as to project in one axial direction. A stop 24 is provided. The locking portion 24 may be integrally molded with the annular portion 23, or the locking portion 24 formed separately may be fixed to the annular portion 23. Then, the crossover wire 31 of the coil wires forming each coil set 40 is engaged with the locking portion 24 of the insulator 20 from the outer diameter side. In this way, the movement of the coil 30 toward the inner diameter side can be restricted via the crossover wire 31 formed by the locking portion 24. In particular, in the illustrated example, since the flange portion 24a (see FIG. 3) extending to the outer diameter side is provided at one end of the locking portion 24 in the axial direction, the crossover wire 31 is engaged with the locking portion 24. It's getting easier.

The present invention is not limited to the above embodiment. Hereinafter, other embodiments of the present invention will be described, but duplicate description will be omitted with respect to the same points as those of the above-described embodiments.

In the embodiment shown in FIGS. 7 and 8, the first U-phase coil set 40 (U1) and the second U-phase coil set 40 (U2) are formed by one continuous coil wire, and the first V phase is formed. The coil set 40 (V1) and the second V-phase coil set 40 (V2) are formed by one continuous coil wire, and the first W-phase coil set 40 (W1) and the second W-phase coil set 40 are formed. (W2) is formed by one continuous coil wire. Then, as shown in FIG. 8, both ends of the coil wires that continuously form the pair of coil sets 40 of each phase are connected to the neutral wire 5a of the bus bar 5 by fusing or the like (star connection). In this way, by forming a pair of coil sets 40 (a total of four coils 30) of each phase with one coil wire, the number of contact points P between the coil 30 and the bus bar 5 is further reduced.

The coil wire forming the U-phase coil sets 40 (U1) and 40 (U2) is provided with a crossover wire 32 (U) connecting both coil sets 40 (U1) and 40 (U2). The coil wire forming the V-phase coil sets 40 (V1) and 40 (V2) is provided with a crossover wire 32 (V) connecting both coil sets 40 (V1) and 40 (V2). The coil wire forming the W-phase coil sets 40 (W1) and 40 (W2) is provided with a crossover wire 32 (W) connecting both coil sets 40 (W1) and 40 (W2). Feed lines 8 from the outside are connected to the crossover lines 32 (U), 32 (V), 32 (W) by fusing or the like, and these contact points Q are provided. As a result, the first U-phase coil set 40 (U1) and the second U-phase coil set 40 (U2), the first V-phase coil set 40 (V1) and the second V-phase coil set 40 (V2) , The first W-phase coil set 40 (W1) and the second W-phase coil set 40 (W2) are connected in parallel, respectively. In this case, the bus bar 5 is provided with only the conductor of the neutral wire 5a, and is not provided with a connection terminal or the like to which the feeder line is connected.

Further, in this embodiment, as shown in FIG. 7, the crossover lines 32 (U), 32 (V), 32 (W) of the coil wires of each phase are arranged on the outer diameter side of the outer peripheral surface of the stator core 10. Has a portion that has been removed. Specifically, the insulator 20 is provided with a locking portion 25 arranged on the outer diameter side of the outer peripheral surface of the stator core 10, and the crossover lines 32 (U), 32 (V), and 32 (W) are locked. It wraps around the outer diameter side of 25. In this way, by arranging a part of each of the crossover lines 32 (U), 32 (V), 32 (W) on the outer diameter side of the stator core 10, the crossover lines 32 (U), 32 (V), It becomes easy to connect the feeding line 8 to 32 (W).

The electric motor 1 as described above is incorporated in, for example, an electric oil pump provided in a vehicle having an idling stop function or a hybrid vehicle. While the engine is stopped, the electric oil pump sucks oil from the oil reservoir at the bottom of the transmission case, discharges this oil, and pumps the oil into the transmission to ensure the required hydraulic pressure in the transmission.

1 Electric motor 2 Stator-coil assembly 3 Rotor 4 Rotating shaft 5 Bus bar 6 Housing 7 Bearing 8 Feeding line 10 Stator core 11 Cylindrical part 12 Teeth 20 Insulator 24 Locking part 30 Coil 31 (connecting coils) Crossing wire 32 (U) ), 32 (V), 32 (W) Crossing wire 40 Coil set P Contact point between coil wire and bus bar Q Contact point between coil wire (crossover wire) and feeding line

Claims (9)

It is a stator-coil assembly of an electric motor having a stator core having a plurality of teeth provided apart from each other in the circumferential direction and a coil wound around each tooth.
A stator-coil assembly in which adjacent in-phase coils are formed by a single continuous coil wire. It has an insulator arranged between the stator core and the coil, and has an insulator.
A locking portion is provided on the insulator to provide a locking portion.
The stator-coil assembly according to claim 1, wherein among the coil wires, a crossover wire connecting adjacent coils having the same phase to each other is engaged with the locking portion of the insulator from the outer diameter side. The stator-coil assembly according to claim 1 or 2, wherein a plurality of coil sets composed of coils having the same phase adjacent to each other are formed, and contacts with a bus bar are provided at both ends of the coil wire of each coil set. A plurality of coil sets consisting of coils having the same phase adjacent to each other are formed, and coil sets having the same phase are provided so as to be spaced apart from each other in the circumferential direction with the coil sets having different phases interposed therebetween.
The stator-coil assembly according to claim 1 or 2, wherein a set of coils having the same phase separated in the circumferential direction is formed of one continuous coil wire, and contacts with a bus bar are provided at both ends of the coil wire. The stator-coil assembly according to claim 4, wherein a contact with a feeder line is provided on a crossover wire connecting coil sets having the same phase separated in the circumferential direction. An electric motor including the stator-coil assembly according to any one of claims 1 to 5, a rotor arranged on the inner circumference of the stator-coil assembly, and a bus bar to which the stator-coil assembly is connected. .. The electric motor according to claim 6, wherein the ratio of the number of magnetic poles of the rotor to the number of grooves between the teeth of the stator and coil assembly is other than 2: 3. The electric motor according to claim 7, wherein the ratio of the number of magnetic poles of the rotor to the number of grooves between the teeth of the stator-coil assembly is 10:12. The electric motor according to any one of claims 6 to 8, wherein the coils of each phase are connected by a star connection.

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