JP2019075854A - Stator - Google Patents

Abstract

To effectively cool a coil end.SOLUTION: A tip side of a coil end 70 protruding from an axial end of a stator core 11 in stator coils 20, 21, 22 of multiple phases is covered with an insulation resin 60 at a predetermined interval from the axial end of the stator core. A coolant is fed toward the coil end between the insulation resin 60 and the stator core. A guide face 64 for guiding the coolant scattered by hitting the coil end onto a stator core side is formed at an axial end of the insulation resin 60 corresponding to a portion to which the coolant is fed.SELECTED DRAWING: Figure 2

Description

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

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

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

  In patent document 1, the insulating film is formed about the stator coil of a coil end part, and the short circuit is prevented.

JP 2012-029355 A

  Here, the rotating electric machine for driving the vehicle has a large output, and the generation of heat by driving is inevitable, and it is necessary to cool. The refrigerant is usually supplied to the rotor and the stator for cooling. In particular, with regard 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 for cooling.

  However, it is difficult to distribute the refrigerant throughout the coil end, and more effective cooling is required.

  In addition, as a refrigerant | coolant, ATF (Automatic transmission fluid) is used normally.

  In the stator according to the present invention, the tip end side of the coil end projecting from the axial end of the stator core among the stator coils of a plurality of phases is covered with the insulating resin with a predetermined gap from the axial end of the stator core A refrigerant is supplied toward the coil end between the insulating resin and the stator core, and at the axial end of the insulating resin corresponding to the portion to which the refrigerant is supplied, a guide surface for guiding the refrigerant jumping against the coil end toward the stator core is Form.

  Further, the insulating resin is annular, and has a guide portion projecting radially outward at a circumferential position corresponding to the portion to which the refrigerant is supplied, and the guide portion gradually extends radially outward to the stator core It is preferred to have a guiding surface which is inclined towards the side.

  The present invention can more effectively cool the coil end by the refrigerant by using the guide surface.

It is a figure showing an example of a coil end of a stator. It is a schematic cross section of the radial direction which shows the coil end of the stator which concerns on embodiment, and insulation resin. It is the 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 based on the drawings. The present invention is not limited to the embodiments described herein.

<Configuration of stator>
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 in order to make it easy to understand the structure and arrangement of the coil, the output wire and the like. 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 body component, and for example, is constituted by laminating a plurality of silicon steel plates (electromagnetic steel plates), but may be constituted by pressure molding a resin binder and magnetic material powder. Good. The stator core 11 has an annular yoke 12 that is annular and located on the outer peripheral side, and a plurality of teeth 16 that extend inward from the yoke 12. The plurality of teeth 16 are disposed at regular intervals in the θ direction, and the teeth 16 project inward in the R direction from the yoke 12 by a predetermined distance. The tips of the teeth 16 are located at a predetermined distance from the outer peripheral surface of the cylindrical rotor, and form a cylinder that generally surrounds the outer peripheral surface of the rotor. The stator coil 15 includes U, V, and W three-phase coils 20, 21 and 22 spirally wound on teeth. The U, V, W three-phase coils 20, 21, 22 are respectively inserted into slots 17 which are spaces between adjacent teeth 16 and wound around the teeth 16.

  The U, V and W three-phase coils 20, 21 and 22 are 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, the ends of which are welded to the ends of the adjacent segment conductors. When welding is performed, the tip sides of the two legs of the U-shaped segment conductor are bent so that the plurality of radially overlapping segment conductors form a spiral, and the tips of the legs of different segment conductors are bent. Weld the parts together. Each segment coil 20 a, 21 a, 22 a is wound around a plurality of teeth 16 so as to straddle a plurality of teeth 16, and a stator coil 15 is wound around a plurality of teeth 16 in a distributed manner.

  One end of each of the coils 20, 21 and 22 of each phase is bent in, 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, U-phase coil 20 is indicated by oblique lines along the θ direction, V-phase coil 21 is indicated by oblique lines along R direction, and W-phase coils 22 are indicated by narrow (fine) oblique lines. There is. In FIG. 1, 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 are illustrated. Further, the other end 20b of U-phase coil 20, the other end 21b of V-phase coil 21, and the other end 22b of W-phase coil 22 are electrically connected by a neutral wire 30, and three-phase coil 20, 21 and 22 are Y-connected by electrical connection using a neutral wire 30. In this example, the neutral wire 30 is disposed outward of one side in the Z direction of the stator core 11.

  A rotor (not shown) is disposed on the inner peripheral side of the stator 1 at a distance from the stator 1. The centers of the stator 1 and the rotor substantially coincide with each other. The rotor is an annular magnetic component fixed to the periphery of the rotation shaft, and, for example, a plurality of annular silicon steel plates (electromagnetic steel plates) are stacked. For example, in the rotor, a plurality of permanent magnets are embedded at intervals in the θ direction.

  The rotating electrical machine including the stator 1 may function as either a motor or a generator. In the case of using the rotating electrical machine as a motor, for example, after the direct current from the battery is converted to a three-phase alternating current through an inverter, the three-phase alternating current passes through the output lines 20U and 22W of each phase. The U, V and W three-phase coils 20, 21 and 22 are supplied. 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 on the basis of the rotating magnetic field to generate rotational power.

  On the other hand, when using a rotating electric machine as a generator and generating electric power, the rotor is rotated by external power, whereby induction of alternating current is performed to U, V, W three-phase coils 20, 21, 22 A current is generated, which is converted to DC power by an inverter and supplied to a battery.

<Configuration of insulating resin>
FIG. 2 is a schematic view of a part 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 including the insulating resin 60 in the R direction. In addition, FIG. 3 is a schematic diagram which showed only the principal part, Comprising: It does not show the exact cross section of various members.

  As shown in FIG. 2, the stator 1 is provided with an insulating resin 60. Insulating resin 60 is disposed to cover one side in the Z direction of coil end 70 located on the one side in the Z direction in stator coil 15. In addition, insulating resin 60 is disposed at an interval in the Z direction with respect to end surface 11 a on one side in the Z direction of stator core 11. That is, in the present embodiment, the leg portions 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, 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 possibility that the joint portion contacts the other joint portion to cause a short circuit. By covering the portion of the coil end 70 in which the bonding portion exists with the insulating resin 60, the bonding portions are isolated and insulated.

  Then, by spacing the end face 11 a of the stator core 11, the portion on the stator core 11 side of the coil end 70 having the insulating film is exposed. Thus, the refrigerant can be brought into direct contact with the coil end exposed portion 72 of this portion for cooling.

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

  Although in FIG. 2 the gap is shown to be closed by the coil end exposed portion 72 of the coil 20, the leg of the segment coil is disposed with a predetermined gap, so the coil The refrigerant can pass from the radially outer side to the inner side of the end exposed portion 72, and the refrigerant is also supplied to the lower coil end exposed portion 72.

<Structure of Guide Unit>
As shown in FIG. 2, the upper end 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 a guide surface 64 of the ATF. As the insulating resin, it is preferable to use a silicone resin, an epoxy resin, or the like.

  The figure which looked at insulating resin 60 from Z-axis direction is shown by FIG. Thus, an arc-shaped guide portion 62 is formed to extend at a position corresponding to the radial upper portion of the annular insulating resin 60. The guide portion 62 extends in a bowl shape from the insulating resin 60 and has a wedge-shaped cross section. In FIG. 3, stator core 11 is indicated by a broken line for convenience.

  Further, in this example, the refrigerant supply unit 50 is formed of an arc-shaped pipe, and a jet port is provided on the lower surface of the pipe. In the lower part of the rotating electrical machine, a refrigerant reservoir is provided, and the refrigerant accumulated here is circulated by a pump or the like to the refrigerant supply unit 50 or other appropriate places. Further, as long as the refrigerant supply unit 50 can supply the refrigerant to the coil end exposed unit 72, any unit may be used. For example, it may be linear or may be jetted from a single point over a wide range.

  The guide surface 64 is positioned to cover the upper side 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 again toward the coil end exposed portion 72, 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 is lowered, but from here, the coil end exposed portion 72 of each phase coil protrudes toward the stator core 11, and the ATF transmitted along 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 which jumps up from the surface of the coil end exposed portion 72 and can not be used for cooling the coil end exposed portion 72 is effectively recovered and used for cooling the coil end exposed portion 72. And can increase the cooling efficiency.

<Configuration of coil wire>
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 at the innermost in the Z direction is included in the U-phase coil 20. A portion 92 a located inward in the Z direction in the coil wire 92 represents a portion of the leg portion of the segment conductor included in the U-phase coil 20 extending in the substantially Z direction from the slot 17 (see FIG. 1). Further, a portion 92b of the coil wire 92 located on the outer side in the Z direction represents a portion that is bent and bent in a direction (θ direction) perpendicular to the paper surface of FIG. 3. In addition, a coil wire 91 which constitutes an intermediate layer in the Z direction is included in the V-phase coil 21. In addition, it is preferable that the connection part of each phase coil 20, 21, 22 and the neutral wire 30, and the connection part of each phase output line and a power line be covered with the insulating resin 60 and be insulated.

DESCRIPTION OF SYMBOLS 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 guiding part, 64 guiding surface, 70 coil end, 72 coil end exposed part, 90, 91, 92 coil wire.

Claims (1)

In the multi-phase stator coil, the tip end side of the coil end projecting from the axial end of the stator core is covered with the insulating resin with a predetermined gap from the axial end of the stator core,
Supply refrigerant to the coil end between the insulating resin and the stator core,
At the axial end of the insulating resin corresponding to the portion to which the refrigerant is supplied, a guide surface is formed to guide the refrigerant jumped against the coil end toward the stator core.
Stator.