JPH0629364U - Motor bracket structure - Google Patents

Abstract

(57) [Abstract] [Purpose] When a bush is press-fitted into the bearing housing part of a motor bracket formed by aluminum die casting, and the bearing is press-fitted into the bush, the difference in the coefficient of thermal expansion of the material causes a change in temperature. An object of the present invention is to provide a bracket structure for an electric motor that prevents the press-fit strength from decreasing. [Structure] A through hole that penetrates the rotary shaft is formed in the center of the bottom portion of the bracket, and a bearing housing portion that protrudes in a ring shape is formed inside, and the open end of the bush is folded back to the outside in accordance with the height of the bearing housing portion. It is characterized in that it is formed into a double cylindrical shape and is press-fitted with the bearing housing portion sandwiched therebetween.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bracket structure of an aluminum die-cast electric motor, and more particularly to a structure of a bearing portion.

[0002]

[Prior art]

 Conventionally, in an electric motor that radiates the heat generated by the operation of a fan motor or the like by air cooling, a bracket made of aluminum die-casting, which has good heat conduction, is often used to improve the heat radiation effect. However, as shown in Fig. 1, a steel ball bearing bearing is often used as the bearing that holds the rotating shaft of the electric motor, and although it is fixed by press-fitting to the bearing housing part of the bracket, the electric motor is driven to generate heat. When the bracket is heated to a high temperature, the holding force due to press-fitting may weaken due to the difference in linear expansion coefficient between the bearing housing and the bearing, which may cause the bearing to rattle. There are methods in which (a) a steel plate bush is directly insert-molded in the housing, (b) the bush is shrink-fitted immediately after molding, or press-fitting after molding is performed to reinforce the bushing with an adhesive or the like. When insert-molding a bush made of steel plate directly, it is necessary to lower the mold temperature in order to set the bush in the mold, and even when shrink-fitting the bush, temperature control of the bracket and bush and the shrink-fitting of the bush are required. Skills are required for the timing, and in each case, there are problems that impair the workability of aluminum die casting. Also, in the method of press-fitting after molding, the holding force after press-fitting decreases depending on the operating temperature range of the electric motor, so it is necessary to reinforce the holding force with an adhesive or the like. It has a problem of significantly reducing productivity.

[0003]

[Problems to be solved by the device]

 The present invention has been made in view of the above conventional problems, and provides a bracket structure for an electric motor capable of securely fixing and holding a steel plate bush in the bearing housing portion of the bracket without impairing workability and productivity. It is intended to be provided.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, a ring-shaped protruding bearing housing portion for press-fitting the bush is formed inside the bracket, and the open end of the bush is folded back according to the height of the bearing housing portion. The bearing housing is sandwiched between two cylinders and press-fitted.

[0005]

[Action]

 According to the above configuration, the bearing housing part protruding in a ring shape for press-fitting the bottomed cylindrical bush is formed inside the bracket, and the open end of the bush is concentric with the height of the bearing housing part. The bush can be securely fixed to the bearing housing portion by pressing back so that the bearing housing portion is press-fitted between the two cylinders so as to sandwich the bearing housing portion. Further, rattling between the bush and the outer wall of the bearing housing due to temperature change can be suppressed and prevented by the inner wall of the outer periphery of the double cylinder or the outer wall of the inner periphery.

[0006]

【Example】

 Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a side sectional view of an essential part of an electric motor according to the present invention. A stator 1 of the electric motor is press-fitted from both sides into spigot parts provided on the open side of the bracket 2 and is centrally held, and the stator 1 has a rotor. 3 is inserted, the bush 5 of the present invention is press-fitted into the bearing housing portion 4 of the bracket 2, and the rotation shaft 7 of the rotor 3 is rotatably supported from both sides by the bearing 6 fixed to the bush 5. Constitutes an electric motor.

FIG. 2 is a side sectional view of a main part of the bracket of the present invention. In the center of the bottom of the bottomed cylindrical bracket 2, a through hole 8 penetrating the rotating shaft 7 of the rotor 3 and a shaft protruding in a ring shape are shown. A receiving housing part 4 is provided. On the other hand, the bush 5 is formed in a bottomed cylindrical shape, and has a through hole 9 for inserting the rotating shaft 7 of the rotor 3 in the center of the bottom and a double cylinder folded outward from a position corresponding to the height of the bearing housing part 4. Forming a cylindrical outer cylinder 10. When the bush 5 is press-fitted into the bearing housing part 4, the bush 5 is press-fitted so that the bearing housing part 4 is sandwiched between the double cylindrical side walls, and the bearing housing part 4 and the inner wall of the outer cylinder 10 and the bearing housing part 4 are It is held by the outer wall of the inner cylinder 11. In this state, when the temperature change of the bracket 2 changes over a wide range due to the operation of the electric motor, etc., when the bearing housing part 4 expands, it is the inner wall of the outer cylinder 10 of the bush 5, and when it contracts, the inner side of the bush 5. It is securely held by the outer wall of the cylinder 11, and it is possible to prevent the bush 5 from rattling and falling off.

[0008]

[Effect of device]

 As described above, in the present invention, the bearing housing portion projecting in a ring shape is provided at the center of the bottom portion of the bracket, and the open end of the bush is folded back to the outside corresponding to the height of the bearing housing portion to form a double cylindrical shape. By press-fitting so that the bearing housing part is sandwiched between two cylinders, it is possible to prevent rattling of the bush due to thermal expansion or contraction of the bracket, and insert molding of the bush during die casting. It is possible to form a motor bracket structure that does not impair the workability and productivity of die-casting without the need for heat-fitting, bushing press-fitting, or reinforcement with an adhesive material. Can be provided.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part of an electric motor according to the present invention.

FIG. 2 is a side sectional view of a main part of the bracket of the present invention.

FIG. 3 is a side sectional view of a main part of a conventional bracket.

[Explanation of symbols]

 1 Stator 2 Bracket 3 Rotor 4 Bearing housing part 5 Bushing 6 Bearing 7 Rotating shaft 8 Through hole 9 Insertion hole 10 Outer cylinder 11 Inner cylinder

Claims (1)

[Scope of utility model registration request] 1. A motor having a cylindrical bottomed bush having a hole through which a rotary shaft is inserted at the center of the bottom, is fixed to a bearing housing of a bracket formed of aluminum die casting, and the bearing is press-fitted into the bush. In the bracket structure, while forming a ring-shaped bearing housing portion for press-fitting the bush inside the bracket, the open end of the bush is folded back to match the height of the bearing housing portion to form a double cylindrical shape. A bracket structure for an electric motor, characterized in that the bearing housing portion is press-fitted so as to be sandwiched between the two cylinders.