JP6798439B2 - Stator - Google Patents

Description

The present invention relates to a stator structure for cooling a stator coil of a rotary electric machine.

Rotating electric machines mounted on electric vehicles such as hybrid vehicles and electric vehicles are cooled because they become hot during use. The rotary electric machine is housed in the case, and the refrigerant is supplied from the upper part of the case and flows from the top to the bottom of the rotary electric machine, so that the refrigerant comes into contact with the stator coil and cools it.

Patent Document 1 discloses a structure in which a plurality of guide grooves for guiding a refrigerant to a coil end of a stator coil are formed on an outer peripheral surface of a stator cuffer installed on an axial end surface of a stator core. The guide groove of the stator cuffer facilitates the flow of refrigerant to the coil end, and the stator coil is cooled well.

Japanese Unexamined Patent Publication No. 2015-130719

Even if a guide groove is formed on the outer peripheral surface of the stator cuff as in Patent Document 1, many refrigerants flow down through the outer peripheral surface of the stator core, and the refrigerant cannot be sufficiently guided to the coil end of the stator coil. There is sex.

An object of the present invention is to sufficiently guide the refrigerant flowing on the outer peripheral surface of the stator core to the coil end and improve the cooling performance of the stator coil.

The stator of the present invention is installed on a cylindrical yoke, a plurality of teeth protruding inward from the inner peripheral surface of the yoke, a stator core having a plurality of slots formed between the teeth, and an axial end surface of the stator core. A stator cuffer having cuffs slots corresponding to the plurality of slots of the stator core, a plurality of the slots of the stator core, and a stator coil wound through the plurality of cuffs slots of the stator cuffer are provided by a refrigerant. A stator in which the coil end of the stator coil is cooled, and the stator cuffer is a rib that projects outward from the axial end surface of the stator cuffer and extends axially on the outer peripheral surface of the stator core. It is characterized by including a refrigerant introduction rib that guides the refrigerant flowing on the outer peripheral surface of the stator core to the coil end.

According to the present invention, when the stator cuffer is provided with the refrigerant introduction rib, the refrigerant flowing on the outer peripheral surface of the stator core is sufficiently guided to the coil end, and the cooling performance of the stator coil is improved.

It is a block diagram which shows the outline of the cooling device which cools a rotary electric machine. It is an exploded perspective view of a stator. It is an enlarged perspective view of the stator to which the stator cuffer is attached. It is a perspective view which shows the flow of the refrigerant in a stator. It is a schematic side view which shows the flow of the refrigerant in a stator.

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

FIG. 1 is a configuration diagram showing an outline of a cooling device 80 for cooling the rotary electric machine 100 of the present embodiment. The rotary electric machine 100 and the cooling device 80 of the present embodiment are mounted on an electric vehicle such as a hybrid vehicle or an electric vehicle. The rotary electric machine 100 functions as a motor to drive the wheels of the electric vehicle by the electric power supplied from the battery (not shown) during power running, and functions as a generator during braking to recover the regenerated energy and charge the battery. Since the rotary electric machine 100 becomes hot when operated as a motor or a generator, it is cooled by the cooling device 80.

As shown in FIG. 1, the rotary electric machine 100 is housed in the case 81. The rotary electric machine 100 includes a rotor 90 and a stator 10. The rotor 90 is connected to a drive shaft 92 that is rotatably supported with respect to the case 81. A plurality of permanent magnets (not shown) are arranged on the rotor 90. The stator 10 is held in the case 81 in a state where the inner peripheral side is arranged to face the rotor 90 with a gap. The stator 10 includes a stator coil 30 as described later. A drive current is supplied to the stator coil 30, and the rotor 90 rotates with respect to the stator 10 due to the electromagnetic force generated in the stator coil 30 by the drive current.

As shown in FIG. 1, the cooling device 80 cools the components of the rotary electric machine including the stator coil by supplying the refrigerant into the case 81. The refrigerant is, for example, a cooling oil called ATF (Automatic Transmission Fluid). The cooling device 80 includes a refrigerant flow path 82 provided outside the case 81, and a refrigerant pipe 83 connected to the refrigerant flow path 82 and provided at the upper end inside the case 81. The refrigerant pipe 83 exists so as to extend in the axial direction of the drive shaft 92. The refrigerant flow path 82 has a refrigerant pump 85, sucks the refrigerant accumulated in the lower part of the case 81, and circulates and supplies the refrigerant to the refrigerant pipe 83. The refrigerant pipe 83 has an ejection port 84 for ejecting the refrigerant downward, and by ejecting the refrigerant from the ejection port 84, the refrigerant comes into contact with the rotary electric machine 100 while flowing down, and the rotary electric machine including the stator coil. 100 components are cooled. After cooling the stator coil and the like, the refrigerant will be accumulated in the lower part of the case 81 again.

Next, the stator 10 of the rotary electric machine 100 of the present embodiment will be described in detail. FIG. 2 is an exploded perspective view of the stator 10 of the present embodiment. As shown in FIG. 2, the stator 10 includes a stator core 20, stator cuffs 40 and 50 covering both ends of the stator core 20 in the axial direction, and a stator coil 30 (segment coil) wound around the stator core 20.

The stator core 20 is formed by laminating a large number of electromagnetic steel plates. The stator core 20 includes an annular yoke 21 extending along the circumferential direction of the stator, and a plurality of teeth 22 protruding inward from the inner peripheral surface of the yoke 21. The plurality of teeth 22 are arranged at equal intervals with each other in the circumferential direction of the stator. Slots 23 are formed between the teeth 22 adjacent to each other in the circumferential direction of the stator, and a plurality of slots 23 are arranged at equal intervals in the circumferential direction of the stator. Each tooth 22 and each slot 23 extends along the stator axial direction.

A pair of stator cuffs 40 and 50 are mounted on the other end surface and the one side end surface of the stator core 20 in the stator axial direction, respectively. The stator cuffer 40 is an insulating resin molding member, and is formed of, for example, an epoxy resin. The stator cuffer 40 includes an outer peripheral side annular member 41 in contact with the yoke on the other end surface in the stator axial direction, an inner peripheral side annular member 42 in contact with the inner tip of the teeth 22 of the stator core 20, and an outer peripheral side annular member 41 and an inner peripheral side annular member. It is provided with a plurality of radial members 43 connecting the 42.

As shown in FIG. 2, the radial members 43 are provided corresponding to the teeth 22 of the stator core 20, and are arranged at equal intervals in the circumferential direction like the teeth 22 to cover the teeth 22 of the stator core 20. ing. A cuffs slot 44 is formed between adjacent radial members 43, and the cuffs slot 44 corresponds to the position of the slot 23 of the stator core 20.

The stator cuffer 50 has the same configuration as the stator cuffer 40, and the stator cuffer 40 is turned upside down and arranged on one end surface in the stator axial direction. Therefore, in each drawing, each part of the stator cuffer 50 is designated by a reference numeral corresponding to the stator cuffer 40, and the description of each part will be omitted.

The stator coil 30 of the present embodiment is a segment coil, and the segment coil is composed of a plurality of conductor segments 31 inserted into all the slots 23 in the circumferential direction of the stator core 20. Although only a pair of conductor segments 31 are shown in FIG. 2, the conductor segments 31 are inserted into all the slots 23 of the stator core 20.

The conductor segment 31 is U-shaped and includes two linear legs 31a and a curved portion 31b connecting them. When the legs 31a of the conductor segment 31 are inserted into the cuffs slot 54 of the stator cuffs 50, the slot 23 of the stator core 20, and the cuffs slots 44 of the stator cuffs 40, the legs 31a have a length protruding from the cuffs slots 44. The portion of the leg 31a protruding from the cuffs slot 44 is bent and joined to the leg 31a of the other conductor segment 31.

As shown in FIG. 2, the stator cuffs 40 and 50 have a plurality of ribs (refrigerant introduction ribs 60) extending inward in the stator axial direction at intervals in the stator circumferential direction. In this embodiment, each of the stator cuffs 40 and 50 has six refrigerant introduction ribs 60. FIG. 3 is an enlarged perspective view of the stator 10 to which the stator cuffs 40 are attached. In FIG. 3, only one refrigerant introduction rib 60 is shown. As shown in FIG. 3, the refrigerant introduction rib 60 projects outward from the axial end surface of the outer peripheral side annular member 41 of the stator cuffer 40, faces outward in the radial direction, and then axially inward on the outer peripheral surface of the stator core 20. It is growing toward.

FIG. 4 is a perspective view of the stator 10 of the present embodiment, and FIG. 5 is a schematic side view of the stator 10 of the present embodiment. In FIG. 4, the stator coil is omitted.

As shown in FIG. 4, in the present embodiment, the two stator cuffs 40 and 50 are installed on the stator core 20 so that the refrigerant introduction ribs 60 face each other in the stator axial direction. Further, as shown in FIG. 4, in the present embodiment, the length of the refrigerant introduction rib 60 located on the upper side is shorter than that of the refrigerant introduction rib 60 located on the lower side in the axial direction. There is. This makes it easier for the refrigerant to pass between the refrigerant introduction ribs 60 located on the upper side and reach the refrigerant introduction ribs 60 located on the lower side.

In FIGS. 4 and 5, the flow of the refrigerant is indicated by a thick black arrow. The refrigerant ejected from the outlet of the refrigerant pipe flows on the outer peripheral surface of the stator core 20 from the upper side to the lower side. Then, when the refrigerant flows to the upper side of each refrigerant introduction rib 60 located on the outer peripheral surface of the stator core 20, the refrigerant is guided toward the axial end surface of the stator through the upper side of the refrigerant introduction rib 60. As a result, as shown in FIG. 5, the refrigerant is guided to the coil end 34 of the stator coil. The coil end 34 is a portion of the stator coil that protrudes from the axial end surface of the stator cuffer. In this way, the refrigerant introduction rib 60 guides the refrigerant flowing on the outer peripheral surface of the stator core 20 to the coil end 34. As a result, the coil end 34 is sufficiently cooled by the refrigerant.

According to the stator 10 of the present embodiment described above, when the stator cuffs 40 and 50 are provided with the refrigerant introduction ribs 60, the refrigerant flowing on the outer peripheral surface of the stator core 20 is sufficiently guided to the coil end 34. Therefore, the cooling performance of the stator coil can be improved.

In the stator 10 of the embodiment described above, six refrigerant introduction ribs 60 are provided in one stator cuffer, but it is natural that other number of refrigerant introduction ribs 60 may be provided.

In the stator 10 of the embodiment described above, the length of the refrigerant introduction rib 60 located on the upper side is shorter than that of the refrigerant introduction rib 60 located on the lower side in the axial direction. However, the length of the refrigerant introduction rib 60 extending inward in the axial direction is not limited thereto. For example, all the refrigerant introduction ribs 60 may have the same length extending inward in the axial direction.

10 refrigerant, 20 stator core, 21 yoke, 22 teeth, 23 slots, 30 stator coils, 31 conductor segments, 31a legs, 31b curved parts, 34 coil ends, 40,50 stator cuffs, 41,51 outer peripheral annular members, 42,52 Inner circumference side annular member, 43,53 radial member, 44,54 cuffs slot, 60 refrigerant introduction rib, 80 cooling device, 81 case, 82 refrigerant flow path, 83 refrigerant pipe, 84 outlet, 85 refrigerant pump, 90 rotor, 92 drive shaft, 100 rotating electric machine.

Claims (1)

A cylindrical yoke, a plurality of teeth protruding inward from the inner peripheral surface of the yoke, and a stator core having a plurality of slots formed between the teeth.
A stator cuffer installed on the axial end face of the stator core and having cuffer slots corresponding to a plurality of the slots of the stator core.
A stator comprising a plurality of the slots of the stator core and a stator coil wound through the plurality of cuffer slots of the stator cuffer, wherein the coil end of the stator coil is cooled by a refrigerant.
The stator cuffer
A rib that protrudes outward from the axial end surface of the stator cuff and extends axially on the outer peripheral surface of the stator core, and is a refrigerant introduction rib that guides the refrigerant flowing on the outer peripheral surface of the stator core to the coil end. With,
A stator characterized by that.

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