JPH0670508A - Electric rotary machine - Google Patents

Abstract

PURPOSE:To provide an electric rotary machine having improved heat transmission and cooling performance from a stator coil to a housing. CONSTITUTION:An outer surface of a metal ring 8a, 8b fitted to a coil end 7 of a stator coil in tight contact with the inner surface of a housing 1, and an adhesive tape 91 and a filler 92 as electrical insulation members are placed between the inner surface of the metal ring 8a, 8b and the surface of a coil end 7. Therefore, heat from the coil end 7 is transmitted to the metal ring 8a, 8b through the electric insulation member, particularly a thin adhesive tape 91, and heat is radiated outside from the metal ring 8a, 8b through housing 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 1-2202140 discloses a vehicle generator in which an annular surrounding groove for covering a coil end of a stator coil is provided on an inner surface of a bracket on both sides forming a part of a housing. It is disclosed that the gap between the coil ends is filled with a filler having good thermal conductivity.

[0003]

However, in the rotary electric machine of the above-mentioned publication, since the annular enclosure groove surrounding the stator coil is formed on the inner surface of the bracket, when accommodating the stator coil in the annular enclosure groove. There is a risk that the stator coil will be rubbed by the annular enclosing groove and the enamel on the surface of the stator coil will peel off, so that the annular enclosing groove must be formed sufficiently large. In addition, after the stator coil is housed in the annular enclosing groove, the electrically insulating filler is injected into the gap between the annular enclosing groove and the stator coil. It does not rotate evenly, and pores are created, resulting in poor heat transfer. On the other hand, if the gap between the annular surrounding groove and the stator coil is increased as described above, the heat transfer resistance from the stator coil to the bracket increases and the cooling performance deteriorates.

Further, in the above-described vehicle generator, the filler must be separated and dropped during disassembly, which is troublesome to process and reassemble. The present invention has been made in view of the above problems, and an object thereof is to provide a rotary electric machine with improved heat transfer cooling performance from a stator coil to a housing.

[0005]

A rotating electric machine according to the present invention has a housing, a rotor core rotatably supported by the housing and around which a rotor coil is wound, and an inner peripheral surface fixed to the inner peripheral surface of the housing. A stator core facing the outer peripheral surface of the rotor core with a minute gap, a stator coil having coil ends protruding from both end surfaces of the stator core and wound around the stator core, an inner surface of the housing and the coil end. And a heat transfer member that transfers heat of the coil end to the housing, the heat transfer member is fitted to the coil end, and the outer surface of the heat transfer member is closely attached to the inner surface of the housing. And an electrically insulating member interposed between the inner surface of the metal ring and the surface of the coil end. That.

The inner surface of the metal ring is the surface on the coil end side, and the outer surface of the metal ring is the surface on the housing side. The shape of the metal ring means an annular member that is in close contact with the coil end through an electrically insulating member and directly with the housing through a heat transfer member. In a preferred embodiment,
The electrical insulation member is an electrical insulation film attached to the inner surface of the metal ring.

[0007]

The outer surface of the metal ring body fitted to the coil end of the stator coil is in close contact with the inner surface of the housing, and the electrically insulating member is provided between the inner surface of the metal ring body and the surface of the coil end. Therefore, the heat of the coil end is transferred to the metal ring body through the electrical insulating member, and is radiated from the metal ring body to the outside through the housing.

[0008]

As described above, the rotary electric machine according to the present invention has a metal ring body fitted between the coil end and the outer surface of which closely contacts the inner surface of the housing, and the metal ring body between the inner surface of the metal ring and the coil end surface. Since the electric insulating member is provided, the following effects can be obtained. First, instead of accommodating the coil end in the annular surrounding groove formed in the housing as in the conventional case, a metal ring body that is significantly lighter than the housing (including the bracket) is fitted to the coil end, and then the stator core is inserted. , The stator assembly consisting of the stator coil and the metal annulus can be inserted and assembled in the housing, which makes the coil end fitting work easier and smoother than before and less damage to the enamel of the coil end. The coil end accommodating groove can be narrowed. As a result, the amount of electrically insulating member in the metal ring can be reduced, and the heat dissipation performance is improved.
That is, since the metal ring body is fitted to the coil end in advance, the coil end does not rub against the inner surface of the housing when the stator assembly is fitted into the housing. Further, unlike the conventional case, it is not necessary to inject the electric insulating member into the metal ring body after the stator assembly is fitted into the housing, and the electric insulating member can be easily filled. The groove can be narrowed, and the filling amount of the electrically insulating member can be reduced to reduce the heat transfer resistance. In addition, the housing does not require an electrically insulating member injection port, and the inside and outside of the housing are completely separated.

Next, since the electrically insulating member is provided between the coil end and the metal ring body, the stator assembly in which the metal ring body is fitted to the coil end can be detached from the housing during disassembly. The electric insulating member does not become an obstacle during the reassembly work. In particular, by attaching an electric insulation film to the surface of the metal ring body that contacts the coil end, it is possible to avoid damaging the enamel of the coil end when press-fitting the coil end into the metal ring body, and even to some extent. Even if damaged, the deterioration of the electrical insulation performance of the coil is reduced. Further, in this case, by making the coil end a little larger than the coil end accommodating groove, the coil end is pressed by the electric insulating film in the coil end accommodating groove, and the coil end and the metal ring body are separated from each other. The heat transfer resistance is greatly reduced compared to the past.

[0010]

(Embodiment 1) An embodiment of a rotating electric machine of the present invention will be described with reference to FIGS. 1 and 2. This rotary electric machine has a cylindrical front housing 1 having a rear end opening, a rear housing 2 fitted and fastened to the rear end opening of the front housing 1 to close the rear end opening, and a rear end surface of the front housing 1. And a bracket 3 that covers the rear housing 2. These are made of aluminum alloy castings.

Front housing 1 and rear housing 2
A field core 5 fixed to a rotating shaft 4 that is rotatably supported by the housing is housed in an internal space S1 between the front housing 1 and the rear housing 2, while between the rear housing 2 and the bracket. A slip ring 41 is fitted to the rear end of the rotary shaft 4 protruding into the internal space S2.

A field coil (a rotor coil in the present invention) 51 is wound around a field core (a rotor core in the present invention) 5. On the other hand, the inner peripheral surface of the front housing 1 has an armature coil (stator coil in the present invention).
The stator core 6 wound with is fixed, and the inner peripheral surface of the stator core 6 faces the outer peripheral surface of the field core 5 through a minute gap G. It should be noted that in FIG. 1, only both coil ends 7, 7 of the armature coil are shown.

A brush (not shown) which is in sliding contact with the slip ring 41 is built in the internal space S2. The features of the present invention will be described below. A metal ring 8a is fitted to the front coil end 7, and a metal ring 8b is fitted to the rear coil end 7.

The metal rings 8a and 8b are substantially the same in shape and are made of an aluminum alloy casting having good heat conductivity. Metal ring 8a, 8
b is a coil end accommodating groove 8 having a substantially rectangular radial cross section
The coil end accommodating groove 80 is open toward the stator core 6 side.
That is, the metal annular bodies 8a and 8b have an opening on the side of the stator core 6 and have an annular tubular shape that covers the tip end surfaces, outer peripheral surfaces, and inner peripheral surfaces of the coil ends 7, 7.

The metal annular body 8a surrounds the coil end accommodating groove 80, has an outer peripheral wall portion 81 on its outer peripheral side, a front end wall portion 82 on its axial front side, and an inner peripheral wall on its inner peripheral side. It has a portion 83. The outer peripheral surface of the outer peripheral wall portion 81 is in close contact with the inner peripheral surface of the front housing 1, and the rear end surface of the outer peripheral wall portion 81 is in close contact with the front end surface of the stator core 6 via the annular plate 61. The annular plate 61 is used for the stator core 6
Is welded to the end surface of the annular plate 61, and a female screw hole (not shown) is provided in the annular plate 61.
b is fastened with a screw. The front end wall portion 82 is in close contact with the inner surface of the front end of the front housing 1, and the front end wall portion 82 has a plurality of holes 8 in the centrifugal direction from the inner peripheral surface side thereof.
4 is drilled. The holes 84 are formed to reduce the weight. The inner peripheral wall portion 83 extends from the inner peripheral portion of the front end wall portion 82 toward the rear side in the axial direction, and has an axial width of about 10 between the rear end of the inner peripheral wall portion 83 and the front end surface of the stator core 6.
A mm opening is provided.

By the way, the outer peripheral wall 81 has an axial width of about 42 mm, a radial thickness of about 7 mm, the front end wall 82 has an axial thickness of about 11 mm, a radial length of about 36 mm, and a front end wall. The length from the front end of the portion 82 to the rear end of the inner peripheral wall portion 83 is about 32 mm, and the radial thickness of the inner peripheral wall portion 83 is about 1 mm. The metal ring body 8b has substantially the same shape as the metal ring body 8a.

However, the outer peripheral wall portion 81 may be cut out on the rear side, and the rear end wall portion 82 may be in close contact with the inner surface concave portion 21 on the inner space S1 side of the rear housing 2, but in this embodiment. So not close. However, the cutout portion 85 of the metal ring body 8b and the outer circumferential side convex portion 22 of the rear housing 2 on the inner space S1 side are in close contact with each other to position the stator assembly in the axial direction, and the rear end wall portion 82 is formed of metal. Ring 8a
The concave portion corresponding to the hole portion 84 is not formed.

Further, in this embodiment, the metal ring members 8a and 8b are used.
Thickness of about 6 on the entire surface facing the coil end receiving groove 80 of
An adhesive tape 91 made of 0 μm polyimide resin is attached. Further, after the coil ends 7, 7 are housed in the coil end housing groove 80, epoxy resin is filled in the voids inside the coil end housing groove 80 (particularly in the vicinity of the openings of the metal ring bodies 8a, 8b) with the metal ring body 8a. The filling portion 92 is mainly injected and filled from the opening between the inner peripheral wall portion 8b of 8b and the stator core 6 and is heat-cured.

It should be noted that, in the past, since the injection was carried out after the assembling, the injection could not be sufficiently performed, but according to this embodiment, the stator core 6 which will be described later is soaked in the liquid resin with the metal ring bodies 8a, 8b assembled. Since it can be filled, sufficient filling is possible. The adhesive tape 91 and the filling portion 92 described above constitute the heat transfer member in the present invention. Also,
A cooling pipe (not shown) through which the cooling liquid flows is brought into close contact with the front housing 1 for heat transfer cooling.

Next, the process of forming the heat transfer member will be described. First, the adhesive tape 91 is applied to the inner surfaces of the metal rings 8a and 8b.
After sticking, the coil ends 7, 7 are inserted into the coil end housing grooves 83. Here, the coil end 7,
The size of each part of 7 is equal to or slightly larger than that of the coil end housing groove 83. However, since the coil ends 7, 7 are elastic, the coil ends 7, 7 are
The coil ends 7, 7 are accommodated in the coil end accommodating groove 83 by slightly contracting. Of course, the coil ends 7 and 7 adhere to the adhesive tape 91, but the adhesive tape 91
Satisfactorily electrically insulates the coil ends 7, 7 from the metal ring bodies 8a, 8b. The adhesive tape 91 is thin and its heat transfer resistance is small.

Next, bolts (not shown) are respectively passed through through holes (not shown) formed through the metal ring bodies 8a and 8b in the axial direction, and the tips of the bolts are provided on the annular plate 61. The metal ring bodies 8a, 8 are screwed into and screwed into screw holes (not shown).
b is fixed to the stator core 6. This bolt is used as a temporary fixing so that the metal ring bodies 8a and 8b do not separate from the stator core 6 even if an epoxy resin is injected and cured or a spring bag of the coil ends 7 and 7 occurs. You may substitute by caulking.

Next, a liquid epoxy resin or the like is injected into the voids remaining particularly on the outer peripheral side of the openings of the metal ring members 8a and 8b and thermally cured to harden the coil ends 7 and 7 and to collect air pockets. It is removed to reduce the heat transfer resistance between the coil ends 7 and 7 and the metal ring bodies 8a and 8b. Finally, the stator assembly is fitted into the front housing 1 by shrink fitting or the like.

According to the heat transfer member of the present invention thus constructed, the following effects can be obtained in addition to the effects described above. The radiant heat of the field coil 51 and the field core 5 is not absorbed by the coil ends 7 and 7 but reflected by the metal rings 8a and 8b, or absorbed by the metal rings 8a and 8b. To the coil ends 7, which is advantageous for cooling the coil ends 7.

The heat of the coil ends 7, 7 is not radiated to the rotor 5 either. That is, the metal ring bodies 8a and 8b prevent heat transfer between the stator and the rotor, and release the heat to the frame. The heat generated by the stator core 6 is also generated by the metal ring body 8.
The heat is transferred to the front housing 1 through a and 8b and cooled.

In the above embodiment, for example, when the rectifier is not fixed to the rear housing and the rear housing 2 may be warmed, the metal ring 8 on the rear side is used.
It is possible to bring the rear end surface of b into close contact with the front end surface of the rear housing 2, thereby improving strength and cooling efficiency. The adhesive tape 91 can also be formed by applying and drying a resin liquid. It is also possible to apply a silicon compound having good heat conductivity to the outer peripheral surfaces of the metal ring bodies 8a and 8b or the inner peripheral surface of the front housing 1. (Embodiment 2) FIG. 2 shows another embodiment.

In this embodiment, in order to increase the contact area between the metal ring bodies 8a and 8b and the front housing 1, linear spline-shaped concavo-convex portions 100 and 101 are provided on their contact surfaces. The reason why the uneven portion 101 on the rear side is larger than the uneven portion 100 on the front side is that the stator core 6 is fitted in the front housing 1 in the axial direction.

In this way, the contact area between the metal annular bodies 8a, 8b and the front housing 1 increases, and the heat transfer resistance at the boundary between the two increases, and the cooling efficiency improves. it can.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a rotating electric machine according to the present invention.

FIG. 2 is a sectional view of Example 2,

[Explanation of symbols]

1 is a front housing (housing), 2 is a rear housing (housing), 3 is a bracket (housing), 51 is a rotor coil, 5 is a rotor core, 6 is a stator core, 7 is a coil end of a stator coil, 8a,
8b is a metal ring, 91 is an adhesive tape (electrical insulating film), 9
2 is a filling member, and 8a, 8b, 91 and 92 are heat transfer members.

Claims (2)

[Claims] 1. A housing, a rotor core rotatably supported by the housing and on which a rotor coil is wound, and an outer circumference of the rotor core fixed to the inner circumference of the housing with a small gap between the inner circumference. A stator core facing the surface,
A stator coil having coil ends protruding from both end surfaces of the stator core and wound around the stator core;
A rotary electric machine comprising: a heat transfer member that is in close contact with an inner surface of the housing and a surface of the coil end, and transfers heat of the coil end to the housing, wherein the heat transfer member is fitted to the coil end. A metal ring whose outer surface is in close contact with the inner surface of the housing,
An electric rotating machine comprising: an electric insulating member interposed between the inner surface of the metal ring and the surface of the coil end. 2. The rotating electric machine according to claim 1, wherein the electric insulating member is an electric insulating film attached to the inner surface of the metal ring.