JP6852639B2 - Stator - Google Patents

Description

The present invention relates to a stator whose coil end is coated with an insulating resin.

The stator of a rotary electric machine has a multi-phase stator coil wound around a tooth provided on a stator core, and a rotating magnetic field is formed by supplying a predetermined current to the stator coil to rotate the rotor. A segment coil is often used as the stator coil. In this case, after inserting the segment coil into the slot between the teeth, it is bent and connected to another segment coil (normal welding) to form each phase coil. The stator coil is often three-phase, and the connecting portion of the stator coil of each phase forms a coil end protruding from the stator core.

The conductor is exposed at the connection portion of the segment coil, and it is necessary to insulate the coil end portion in order to prevent a problematic short circuit.

In Patent Document 1, an insulating film is formed on the stator coil at the coil end portion to prevent a short circuit.

Japanese Unexamined Patent Publication No. 2012-0293555

Here, the rotary electric machine for driving the vehicle has a large output, and it is inevitable that heat is generated by the driving, and it is necessary to cool the electric machine. Usually, the refrigerant is supplied to the rotor and the stator to cool them. In particular, with respect to the stator, it is preferable to bring the refrigerant into contact with the stator coil that generates heat, and in many cases, the refrigerant is injected toward the coil end to cool the stator.

However, it is difficult to spread the refrigerant over the entire coil end, and more effective cooling is required.

As the refrigerant, ATF (Automatic transmission fluid) is usually used.

In the stator according to the present invention, the tip end side of the coil end protruding from the axial end of the stator core in the multi-phase stator coil is covered with an annular insulating resin with a predetermined gap from the axial end of the stator core. Then, the refrigerant is supplied toward the coil end between the insulating resin and the stator core, and the axial end of the insulating resin at the circumferential position corresponding to the portion to which the refrigerant is supplied projects radially outward and the coil end. A guide portion is provided to guide the refrigerant that bounces off the refrigerant toward the stator core side, and this guide portion has a guide surface that is inclined so as to gradually approach the stator core side toward the outside in the radial direction.

Further, the insulating resin is annular and has a guide portion that protrudes radially outward at a circumferential position corresponding to a portion to which the refrigerant is supplied, and this guide portion gradually extends outward in the radial direction to the stator core. It is preferable to have a guide surface that is inclined so as to approach the side.

According to the present invention, the guide surface can be used to more effectively cool the coil end with the refrigerant.

It is a figure which showed an example of the coil end of a stator. It is a schematic cross-sectional view in the radial direction which shows the coil end and the insulating resin of the stator which concerns on embodiment. It is a schematic diagram which looked at the insulating resin of the stator which concerns on embodiment from the axial direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described herein.

<Constituent configuration>
FIG. 1 is a partial perspective view of a stator 1 of a rotary electric machine according to an embodiment of the present invention. In FIG. 1, the insulating resin is not shown so that the structure and arrangement of the coil, output line, etc. can be easily understood. Further, in the following drawings and description of the embodiment, the R direction indicates the radial direction of the stator 1, the θ direction indicates the circumferential direction of the stator 1, and the Z direction indicates the axial direction of the stator 1.

The stator 1 includes a stator core 11 and a stator coil 15 including a flat wire. The stator core 11 is an annular magnetic component. For example, a plurality of silicon steel sheets (electromagnetic steel sheets) are laminated, but even if the stator core 11 is formed by pressure molding a resin binder and a magnetic material powder. Good. The stator core 11 has an annular yoke 12 located on the outer peripheral side in an annular shape, and a plurality of teeth 16 extending inward from the yoke 12. The plurality of teeth 16 are arranged at regular intervals in the θ direction, and each tooth 16 projects from the yoke 12 inward in the R direction by a predetermined distance. The tip of each tooth 16 is located at a predetermined gap with respect to the outer peripheral surface of the cylindrical rotor, and forms a cylinder that surrounds the outer peripheral surface of the rotor as a whole. The stator coil 15 includes U, V, and W three-phase coils 20, 21, and 22 spirally wound around the teeth. Each of the U, V, and W three-phase coils 20, 21, and 22 is inserted into a slot 17 which is a space between adjacent teeth 16 and wound around the teeth 16.

Each of the U, V, and W three-phase coils 20, 21, and 22 is connected in series by sequentially connecting the ends of the plurality of segment coils 20a, 21a, and 22a. Each of the segment coils 20a, 21a, 22a is a plurality of substantially U-shaped segment conductors whose ends are welded to the ends of adjacent segment conductors. When welding, the tip ends of the two legs of the U-shaped segment conductor are bent so that a plurality of segment conductors overlapping in the radial direction form a spiral, and the tips of the legs of different segment conductors are bent. Weld the parts together. Each of the segment coils 20a, 21a, 22a is wound around a plurality of teeth 16 so as to straddle the plurality of teeth 16, and the stator coil 15 is distributedly wound around the plurality of teeth 16.

In the coils 20, 21 and 22 of each phase, one end thereof is bent into, for example, a crank shape to become an output line, and the output line of each phase is electrically connected to a power line (not shown) on the power supply side. In FIG. 1, the U-phase coil 20 is indicated by a diagonal line along the θ direction, the V-phase coil 21 is indicated by a diagonal line along the R direction, and the W-phase coil 22 is indicated by a narrow (fine) diagonal line. There is. FIG. 1 shows an output line 20U at one end of the U-phase coil 20 and an output line 22W at one end of the W-phase coil 22. Further, the other end 20b of the U-phase coil 20, the other end 21b of the V-phase coil 21, and the other end 22b of the W-phase coil 22 are electrically connected by a neutral wire 30, and the three-phase coil 20, The 21 and 22 are Y-connected by an electrical connection using the neutral wire 30. In this example, the neutral wire 30 is arranged on the outer side of the stator core 11 on one side in the Z direction.

Rotors (not shown) are arranged on the inner peripheral side of the stator 1 at intervals from the stator 1. The centers of the stator 1 and the rotor are substantially aligned. The rotor is an annular magnetic component fixed around a rotating shaft, and is composed of, for example, a plurality of annular silicon steel plates (electromagnetic steel plates) laminated. For example, a plurality of permanent magnets are embedded in a rotor at intervals in the θ direction.

The rotary electric machine including the stator 1 may function as either a motor or a generator. When a rotary electric machine is used as a motor, for example, after the direct current from the battery is converted into a three-phase alternating current via an inverter, the three-phase alternating current is transferred via the output lines 20U and 22W of each phase. It is supplied to the U, V, and W three-phase coils 20, 21, and 22. As a result, the teeth 16 are magnetized to become magnetic poles, and a rotating magnetic field is generated in which the positions of the magnetic poles move along the θ direction of the stator 1. Then, the rotor rotates based on the rotating magnetic field, and rotational power is generated.

On the other hand, when a rotary electric machine is used as a generator to generate electricity, the rotor is rotated by external power, which induces alternating current in the U, V, and W three-phase coils 20, 21, and 22. An electric current is generated, which is converted into DC power by an inverter and supplied to the battery.

<Composition of insulating resin>
FIG. 2 is a partial schematic cross-sectional view of the cross-sectional view taken along the line AA of FIG. 1, and is a partial schematic cross-sectional view of the stator 1 containing the insulating resin 60 in the R direction. Note that FIG. 3 is a schematic view showing only the main part, and does not show an accurate cross section of various members.

As shown in FIG. 2, the stator 1 includes an insulating resin 60. The insulating resin 60 is arranged so as to cover one side of the coil end 70 located on one side of the stator coil 15 in the Z direction. Further, the insulating resin 60 is arranged at intervals in the Z direction with respect to the end surface 11a on one side of the stator core 11 in the Z direction. That is, in the present embodiment, the legs of the U-shaped segment coils 20a, 21a, 22a are bent and the tip portions thereof are welded to form spiral three-phase coils 20, 21, 22. The segment coils 20a, 21a, and 22a are basically covered with an insulating film, but since the tip portions thereof are joined by welding, there is no insulating film. Therefore, there is a risk of a short circuit when this joint portion comes into contact with another joint portion. By covering the portion of the coil end 70 where the joint portion is present with the insulating resin 60, the joint portions are isolated and insulated from each other.

Then, the portion of the coil end 70 having the insulating film on the stator core 11 side is exposed by providing a space with respect to the end surface 11a of the stator core 11. As a result, the refrigerant can be brought into direct contact with the coil end exposed portion 72 of this portion to be cooled.

That is, a refrigerant supply unit 50 is provided above the coil end exposed portion 72, from which the refrigerant (ATF) is ejected. Then, the ejected ATF is supplied to the exposed coil end portion 72, and the coil end exposed portion 72 is cooled.

In FIG. 2, it is shown that the gap is closed by the coil end exposed portion 72 of the coil 20, but since the leg portion of the segment coil is arranged with a predetermined gap, the coil Refrigerant can pass from the radial outside to the inside of the end exposed portion 72, and the refrigerant is also supplied to the lower coil end exposed portion 72.

<Structure of information section>
As shown in FIG. 2, the upper end portion of the insulating resin 60 has a guide portion 62 that bulges outward in the R direction and toward the stator core 11 in the Z direction. The surface of the guide portion 62 facing the stator core 11 is the guide surface 64 of the ATF. As the insulating resin, a silicone resin, an epoxy resin, or the like may be used.

FIG. 3 shows a view of the insulating resin 60 as viewed from the Z-axis direction. In this way, the arc-shaped guide portion 62 is formed so as to extend at a position corresponding to the upper portion of the annular insulating resin 60 in the radial direction. The guide portion 62 extends from the insulating resin 60 in an eaves shape and has a wedge shape in cross section. In FIG. 3, the stator core 11 is shown by a broken line for convenience.

Further, in this example, the refrigerant supply unit 50 is formed of an arc-shaped pipe, and a spout is provided on the lower surface of the pipe. A refrigerant pool is provided in the lower part of the rotary electric machine, and the refrigerant collected here is circulated to the refrigerant supply unit 50 and other appropriate places by a pump or the like. Further, the refrigerant supply unit 50 may be any as long as it can supply the refrigerant to the coil end exposed unit 72. For example, it may be linear or may be sprayed over a wide range from one point.

The guide surface 64 is located so as to cover the upper part of the coil end exposed portion 72 to which the ATF is supplied. Therefore, the ATF scattered by the coil end exposed portion 72 collides with the guide surface 64. Then, the bounced ATF falls toward the coil end exposed portion 72 again, and the ATF attached to the guide surface 64 moves downward along the guide surface 64. The inner surface of the insulating resin 60 below the guide surface 64 descends, from which the coil end exposed portion 72 of each phase coil protrudes toward the stator core 11, and the ATF transmitted through the guide surface 64 is also the coil end exposed portion. It is supplied to 72.

As described above, according to the present embodiment, the ATF that jumps up from the surface of the coil end exposed portion 72 and cannot be used for cooling the coil end exposed portion 72 is effectively recovered and used for cooling the coil end exposed portion 72. It is possible to increase the cooling efficiency.

<Coil wire configuration>
As shown in FIG. 2, the coil wires 90, 91, 92 have a three-layer structure in the Z direction. For example, in this cross section, the coil wire 92 located on the innermost side in the Z direction is included in the U-phase coil 20. The portion 92a located inward in the Z direction in the coil wire 92 represents a portion extending in the substantially Z direction from the slot 17 (see FIG. 1) in the leg portion of the segment conductor included in the U-phase coil 20. Further, the portion 92b of the coil wire 92 located on the outer side in the Z direction represents a portion that has been bent and bent in a direction (θ direction) perpendicular to the paper surface of FIG. Further, the coil wire 91 forming the intermediate layer in the Z direction is included in the V-phase coil 21. It is preferable that the connection portion between the phase coils 20, 21 and 22 and the neutral wire 30 and the connection portion between each phase output line and the power line are also insulated by being covered with the insulating resin 60.

1 stator, 11 stator core, 12 yoke, 15 stator coil, 16 teeth, 17 slots, 20 U-phase coil, 20a, 21a, 22a segment coil, 21 V-phase coil, 22 W-phase coil, 30 neutral wire, 50 refrigerant supply Part, 60 Insulation resin, 62 Guide part, 64 Guide surface, 70 Coil end, 72 Coil end exposed part, 90, 91, 92 Coil wire.

Claims (5)

In the multi-phase stator coil, the tip end side of the coil end protruding from the axial end of the stator core is covered with an annular insulating resin with a predetermined gap from the axial end of the stator core.
Supply refrigerant toward the coil end between the insulating resin and the stator core,
At the axial end of the insulating resin at the circumferential position corresponding to the portion to which the refrigerant is supplied, a guide portion is provided to guide the refrigerant that protrudes outward in the radial direction and hits the coil end to the stator core side. The portion has a guide surface that is inclined toward the outer side in the radial direction so as to gradually approach the stator core side .
Stator. The stator according to claim 1.
The guide part bulges toward the stator core at the upper end of the insulating resin.
Stator. The stator according to claim 1.
The guide portion is formed so as to extend in an arc shape at a position corresponding to the radial upper portion of the insulating resin.
Stator. The stator according to claim 1.
The guide part extends from the insulating resin in an eaves shape and has a wedge-shaped cross section.
Stator. The stator according to claim 1.
The guide surface is located so as to cover above the exposed portion of the coil end to which the refrigerant is supplied.
Stator.

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