JPH07227058A - Bearing device and bearing device of AC generator - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a bearing device which can surely fix the bearing and which is easy to assemble. [Structure] Between the bearing 21 and the bracket 7, a detent portion 26 having a larger coefficient of thermal expansion than the bracket 7 integrally formed with the brush holding frame 25 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device used in a vehicle or the like and a bearing device for an AC generator.

[0002]

2. Description of the Related Art Generally, in rotating electric machines such as small generators and electric motors, in order to reduce the weight, a bracket is often made of a light alloy such as aluminum die-cast, and a bearing is often fitted into the bearing box. In that case, in order to prevent the thrust load acting on the bearing from increasing due to the extension of the shaft and the expansion of the bearing itself due to the temperature rise during operation or the ambient temperature rise, further improving the workability of disassembling and reassembling the bearing. Therefore, normally, a clearance fit is provided between the inner peripheral surface of the bearing box of the bracket and the outer peripheral surface of the bearing so that they can move relative to each other. However, in such a structure, the inner peripheral surface of the bearing box of the bracket expands due to the temperature rise, so that a large gap is created between the bearing box and the bearing, and the bearing idles. The inner peripheral surface of the bearing box made of alloy is gradually worn away, and the life of the bearing device is shortened. As a countermeasure against this, a metal ring such as cast iron which is harder than aluminum is inserted into the inner circumference of the bearing box, and a metal ring having a smaller thermal expansion coefficient than the bearing box is fitted into the outer circumference of the bearing box. (For example, Japanese Utility Model Laid-Open No. 56-101164)

FIG. 5 is a sectional view showing a bearing device for a conventional vehicle AC generator, and FIG. 6 is a sectional view showing a brush holder. In these figures, reference numeral 1 is a rotating shaft supported by a bearing 2 (described later) and provided with a slip ring 3 (described later). The rotary shaft 1 is connected to an input shaft (not shown). The bearing 2 is composed of an inner diameter portion 4, a bearing ball 5, and an outer diameter portion 6, and the inner diameter portion 4 is the rotating shaft 1
The outer diameter portion 6 is in contact with a bracket 7 (described later) as a bearing holding member. Further, the outer diameter portion 6 is provided with two annular recesses 6a and 6b.

The bracket 7 is molded by aluminum die casting and is fixed to the outside (not shown).
Between the bracket 7 and the bracket 7, two ring-shaped detents 8 are provided so as to fit in the recesses 6a and 6b. The detent 8 is made of a polymer material having a larger expansion coefficient than the bracket 7. Two slip rings 3 are provided on the rotary shaft 1 and are brought into sliding contact with the brush 9 to supply an electric current for an exciting coil (not shown) from the brush 9. The brush 9 is pressed against the slip ring 3 by a spring 10 and connected to an external power source (not shown) by a connecting wire 11. The brush 9 is held by a brush holding frame 12, and the brush holding frame 12 is fixed to the bracket 7 via a packing 13 so that dust and the like do not enter the bearing 2 through the gap between the brush holding frame 12 and the bracket 7.

Next, the operation will be described. When the rotating shaft 1 is rotating, a large amount of heat is generated from the contact surface between the slip ring 3 and the brush 9, the bearing 2, the stator (not shown) during power generation operation, the rotor (not shown), etc. To do. Due to this heat, the temperature of the outer diameter portion 6, the rotation stopper 8 and the bracket 7 of the bearing 2 rises and they expand according to their respective expansion rates. At this time, if the expansion rate of the bracket 7 is larger than the expansion rate of the outer diameter portion 6, the distance between the bracket 7 and the outer diameter portion 6 becomes wide, but the expansion rate of the rotation stopper 8 is the expansion rate of the bracket 7. Since it is larger, the detent 8 presses and fixes the bracket 7 and the outer diameter portion 6. Moreover, if the detent 8 is damaged when the bearing 2 is press-fitted into the bracket 7, the bearing 2 cannot be securely fixed when the detent 8 expands. Therefore, when the bearing 2 is press-fitted into the bracket 7. For this purpose, a so-called shrink fit is used in which the bracket 7 is preheated and expanded so as not to damage the detent 8, and then the bearing 2 provided with the detent 8 is press-fitted into the bracket 7.

[0006]

Since the conventional bearing device is constructed as described above, in order to securely fix the bearing 2, the detent 8 provided on the bearing 2 is prevented from being damaged. When press-fitting 2 into the bracket 7, it is necessary to use a method such as shrink fitting, so that the assembly work is complicated.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a bearing device in which the fixing of the bearing is reliable and the assembling work is easy.

[0008]

In the bearing device according to the present invention, a detent having a coefficient of thermal expansion larger than that of the bearing holding member and longer than the bearing in the axial direction of the rotating shaft is provided between the bearing holding member and the bearing. It is a thing.

A bearing device for an AC generator according to the present invention is integrally formed with a brush holding frame that holds a brush that is in sliding contact with a slip ring provided on a rotating shaft, and a bearing holding member that holds a bearing that supports the rotating shaft. A detent having a higher coefficient of thermal expansion is provided between the bearing and the bearing holding member.

Further, a detent having a larger coefficient of thermal expansion than a bearing holding member which is integrally formed with a brush holding frame for holding a brush which is in sliding contact with a slip ring provided on the rotary shaft and which holds a bearing for supporting the rotary shaft. It is provided between the bearing and the bearing holding member.

[0011]

In the bearing device according to the present invention, the coefficient of thermal expansion is larger than that of the bearing holding member, and the detent that is longer than the bearing in the axial direction of the rotating shaft is provided between the bearing holding member and the bearing. A detent is interposed between the holding member and the holding member.

A bearing device for an AC generator according to the present invention is integrally formed with a brush holding frame for holding a brush that is in sliding contact with a slip ring provided on a rotary shaft, and a bearing holding member for holding a bearing for supporting the rotary shaft. Since the detent having a higher coefficient of thermal expansion is provided between the bearing and the bearing holding member, the detent is formed integrally with the brush holding frame and then inserted into the bracket.

Further, a detent having a larger coefficient of thermal expansion than a bearing holding member formed integrally with a brush holding frame for holding a brush slidably contacting a slip ring provided on the rotary shaft and holding a bearing for supporting the rotary shaft. Since the detent is provided between the bearing and the bearing holding member, the detent is inserted into the bracket after being molded integrally with the brush holding frame.

[0014]

【Example】

Example 1. 1 is a sectional view showing a bearing device for a vehicle AC generator as a first embodiment of the present invention, and FIG. 2 is a sectional view showing a brush holding frame. In these figures, 21 is a bearing that rotatably supports the rotating shaft 1. The bearing 21 is composed of an inner diameter portion 22, a bearing ball 23 and an outer diameter portion 24, and the inner diameter portion 22 is in contact with the rotating shaft 1. The outer diameter portion 24 is a rotation preventing portion 26 (described later) of the brush holding frame 25 (described later) formed of a polymer material having a large coefficient of thermal expansion.
Is in contact with. The brush holding frame 25 holds the brush 9 and protects the slip ring 3. Further, the brush holding frame 25 is integrally formed with a cylindrical detent portion 26 provided between the bearing 21 and the bracket 7. Since this rotation preventing portion 26 is longer than the bearing 21 in the axial direction of the rotary shaft 1, it protects the bearing 21.

Next, the operation will be described. Due to a large amount of heat generated from the contact surface between the slip ring 3 and the brush 9, the bearing 21, the stator (not shown), the rotor (not shown) during the power generation operation, etc. when the rotating shaft 1 is rotating. , Bearing 21
The outer diameter portion 24, the rotation preventing portion 26, and the bracket 7 expand according to the respective expansion rates. At this time, if the expansion rate of the bracket 7 is larger than the expansion rate of the outer diameter portion 24, the bracket 7
Although the space between the outer diameter portion 24 and the outer diameter portion 24 becomes wider, the expansion coefficient of the rotation preventing portion 26 is larger than the expansion coefficient of the bracket 7, so that the rotation preventing portion 26 presses the bracket 7 and the outer diameter portion 24. Fix it.

Further, in the method of press-fitting the bearing 2 into the bracket 7, first, the anti-rotation portion 26 is press-fitted into the bracket 7,
Next, the bearing 21 is press-fitted into the rotation preventing portion 26.
Since other configurations and operations are similar to those of the conventional technique, the same reference numerals are given and description thereof is omitted.

Example 2. FIG. 3 is a sectional view of a bearing device for a vehicle alternator according to a second embodiment of the present invention. In this figure, 31 is a brush holding frame made of thermosetting resin that holds the brush 9, and 32 is the bracket 7 and the bearing 21.
Is a detent provided so as to be longer than the bearing 21 in the axial direction of the rotating shaft 1. The detent 32 is molded with nylon having a coefficient of thermal expansion larger than that of the bracket 7.

This bearing device is assembled as follows. The detent 32 is press-fitted into the bracket 7, the bearing 21 is press-fitted into the detent 32, and then the brush holding frame 31 is fixed to the bracket 7 by adhesion. Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

Example 3. Fourth Embodiment FIG. 4 is a sectional view of a bearing device for an automotive alternator showing a third embodiment of the present invention. In this figure, 41 is a brush holding frame for holding the brush 9, and 42 is a detent portion integrally formed with the brush holding frame 41. The brush holding frame 41 is molded with a polymer material having a thermal expansion coefficient higher than that of the bracket 7. The rotation preventing portion 42 wraps and fixes the bearing 21 as shown in FIG. 4, and prevents dust and the like from entering the bearing 21.

This bearing device is assembled as follows. The bearing 21 is placed in the rotation preventing portion 42 of the brush holding frame 41.
Press-fitting, and then the rotation stop portion 42 of the brush holding frame 41
Is pressed into the bracket 7 and fixed. Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

In the second embodiment, the brush holding frame 31 may be fixed to the detent 32.

Further, in each of the above-mentioned embodiments, the bearing device of the vehicle alternator has been described, but the bearing device of the other rotating electromagnetic device such as the magnetic particle type electromagnetic coupling device can also be used.

[0023]

In the bearing device according to the present invention, the coefficient of thermal expansion is larger than that of the bearing holding member, and the detent that is longer than the bearing in the axial direction of the rotating shaft is provided between the bearing holding member and the bearing. Since the detent is interposed between the holding member and the holding member, the bearing is reliably held by the bearing holding member via the detent.

A bearing device for an AC generator according to the present invention is integrally formed with a brush holding frame that holds a brush that is in sliding contact with a slip ring provided on a rotating shaft, and a bearing holding member that holds a bearing that supports the rotating shaft. Since the detent with a higher coefficient of thermal expansion is provided between the bearing and the bearing holding member, the detent is formed integrally with the brush holding frame and then inserted into the bracket. Less and more efficient to assemble.

Further, a detent having a larger coefficient of thermal expansion than a bearing holding member formed integrally with a brush holding frame for holding a brush slidably contacting a slip ring provided on the rotary shaft and holding a bearing for supporting the rotary shaft. Since the detent is provided between the bearing and the bearing holding member, the detent is formed integrally with the brush holding frame and then inserted into the bracket, so that the number of parts is reduced and the assembling efficiency is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a bearing device for an automotive alternator as a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a brush holding frame according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a bearing device for a vehicle AC generator as a second embodiment of the present invention.

FIG. 4 is a sectional view showing a bearing device for a vehicle AC generator as a third embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a bearing device of a conventional vehicle alternator.

FIG. 6 is a sectional view showing a conventional brush holding frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating shaft 2 bearing 7 bracket 8 whirl stop 12 brush holding frame 21 bearing 25 brush holding frame 26 whirl stop portion 31 brush holding frame 32 whirl stop 41 brush holding frame 42 whirl stop portion

Claims (3)

[Claims] 1. A bearing for supporting a rotating shaft, a bearing holding member for holding the bearing, and a coefficient of thermal expansion larger than that of the bearing holding member provided between the bearing holding member and the bearing and of the rotating shaft. A bearing device having a detent longer than the above bearing in the axial direction. 2. A bearing for supporting a rotating shaft, a bearing holding member for holding the bearing, a slip ring provided on the rotating shaft, a brush slidingly contacting the slip ring, a brush holding frame for holding the brush, and a brush holding frame for holding the brush. A bearing device for an alternator, which is integrally formed with a brush holding frame, is provided between the bearing and the bearing holding member, and includes a detent having a larger coefficient of thermal expansion than the bearing holding member. 3. The bearing device for an alternator according to claim 2, wherein the brush holding frame and the detent are integrally molded.