JPS6120859Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating electric machine such as an electric motor, and particularly relates to an improvement of a cover for a small rotating electric machine.

In general, in order to make this type of rotating electric machine smaller and lighter, the cover is being changed from being made of alloy die-casting to being made of pressed steel plate. In conventional rotating electrical machines of this type, a cover is fitted around the outer periphery of the stator, and the shaft of the rotor is supported via bearings in the bearing holders of each cover. During press molding, spring back occurs in the bearing holding part, making it difficult to achieve high dimensional accuracy, and even if the bearing holding part is further sized after press forming, it is difficult to achieve high dimensional accuracy. For this reason, in conventional rotating electric machines, the desired dimensional accuracy was achieved by cutting the inner wall of the cylindrical peripheral wall portion of the bearing holder into which the bearing fits, but cutting requires more man-hours and becomes expensive. Not only that, but the wall thickness became extremely thin, resulting in a decrease in strength.

The purpose of the present invention is to provide a rotating electric machine that eliminates the above-mentioned drawbacks by allowing the bearing holding part of the cover to be fitted with sufficient dimensional accuracy only by pressing without cutting. .

The rotating electric machine of the present invention will be described in detail below with reference to the drawings.

In Figures 1 and 2, 1 is a stator in which a stator winding 3 is wound around an iron core 2, 4 is a stator through which a rotating shaft 5 passes, and a large number of blowing blades 6 are formed on both end faces in the axial direction. It is a rotor. Reference numerals 7 and 7 denote bearings fitted onto the shaft 5, and in the illustrated embodiment, ball bearings are used as these bearings. Reference numerals 8 and 9 indicate bowl-shaped covers formed by pressing steel plates, and these covers can be attached to the stator 1 by fitting their open ends 8a and 9a to the outer periphery of the end of the stator core 2. is fixed to. One cover 8 is formed with a cylindrical portion 8c that protrudes inward from an end wall 8b of the cover orthogonal to the shaft 5 in the axial direction of the shaft 5. an inner wall portion 8 d that surrounds the inner wall portion 8 d and an outer wall portion 8 that is continuous with the end portion of the inner wall portion and is folded back from the end portion of the inner wall portion 8 d in a direction opposite to the protruding direction of the inner wall portion.
It is formed into a double structure consisting of e. As shown in FIG. 2, the cylindrical portion 8c is formed in a wave shape in which concave portions and convex portions appear alternately in the circumferential direction, and each top portion protruding inwardly and outwardly is located on a circumference concentric with the shaft 5. It's summery. Each top part protruding inside the cylindrical part 8c is sizing-processed (pressing process is used to ensure dimensional accuracy; a punch with a diameter slightly larger than the diameter connecting each top part is inserted into the cylindrical part 8c, and each top part is sized. By pressing and dipping), a bearing holding reduced surface A with high dimensional accuracy is formed. An end wall 8f that covers one end of the shaft 5 is provided at the outer end of the inner wall portion 8d and has a cylindrical portion 8c.
The end wall 8f and the cylindrical portion 9c are integrally formed with each other.
The first bearing holding section 10 is configured by the above. The first bearing holder 10 has an outer surface with an end wall 8
It is formed to be substantially flush with the outer surface of d.
11 is a second cover formed in the center of the other cover 9.
This is the bearing holding part. Like the first bearing holder 10, the second bearing holder 11 has a cylindrical part 9c that projects inward from the end wall 9b, and this cylindrical part 9c has an inner wall 9d and an outer wall 9e. It is formed into a double structure consisting of. The cylindrical portion 9c is also formed in a wave shape like the first bearing holding portion 10, and a bearing holding pressure lower surface B is formed at each inwardly projecting top portion by sizing processing. An end wall 9f that is flush with the end wall 9d of the cover 9 is formed continuously at the outer end of the inner wall 9d, and a hole 12 through which the shaft 5 of the rotor passes is formed in the end wall 9f. It is provided.

In the above embodiment, the top part protruding inward of the bearing holding part is sized to form the bearing holding pressure lower surfaces A and B. When fitting onto the outer periphery of the bearing holding portion, a highly accurate holding surface can be formed by performing sizing processing on the top portion of the bearing holding portion that protrudes outside.

Further, in the above embodiment, a ball bearing was used as the bearing, but it goes without saying that the present invention can also be applied to a case where a sliding bearing is used.

As described above, according to the present invention, the cylindrical portion of the bearing holding portion is continuous with the inner wall surrounding the outer periphery of the bearing and the end of the inner wall, and extends from the end of the inner wall in the direction of protrusion of the inner wall. The cylindrical part is made into a double structure consisting of an outer wall part folded in opposite directions, and this cylindrical part is made into a corrugated shape in which concave parts and convex parts appear alternately in the circumferential direction, and a bearing holding pressure lowering surface is provided at each top part that protrudes inward of the inner wall part. Therefore, when forming the bearing holding pressure surface by sizing each top protruding inside the inner wall part, the outer wall part suppresses elastic deformation of the inner wall part to create a bearing holding part with high dimensional accuracy and less spring back. , it has the advantage that it can be obtained without cutting as in the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a rotating electrical machine of the present invention, and FIG. 2 is a side view of essential components of the rotating electrical machine of the present invention. DESCRIPTION OF SYMBOLS 1... Stator, 4... Rotor, 8, 9... Cover, 10... First bearing holding part, 11... Second bearing holding part, 8c, 9c... Cylindrical part, A, B...
Bearing holding reduction surface.

Claims (1)

[Scope of utility model registration request] The axial ends of the stator and rotor are covered by a press-molded cover, and the shaft of the rotor is supported by a bearing fitted in a cylindrical bearing holding part integrally provided on the end wall of the cover. In a rotating electrical machine in which a rotating electric machine is supported, the cylindrical portion of the bearing holding portion is continuous with an inner wall surrounding the outer periphery of the bearing and an end of the inner wall, and extends from the end of the inner wall in a direction in which the inner wall protrudes. and an outer wall portion folded back in the opposite direction, and the cylindrical portion is formed in a wave shape in which concave portions and convex portions appear alternately in the circumferential direction, and protrudes inside the wave-shaped inner wall portion. A rotating electric machine characterized in that a bearing holding pressure lower surface that engages with and holds the bearing is formed on each top portion of the rotating electric machine.