JPH09291934A - Thrust ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the necessity of post-machining for an inner peripheral part by forming a pair of bearing rings respectively fixed to the loading parts opposite in an axial direction of two members making eccentric rotations between each other to have no inner peripheries. SOLUTION: A bearing ring 4a (or a bearing ring 4b in a fixed side: the bearing rings 4a and 4b are similar in shape) in the turning side of a thrust ball bearing is formed by press-machining a steel plate billet, and a plurality of recessed bearing surfaces 4a1 (4b1) are formed in one end surface thereof. Each bearing surface 4a1 (4b1) is annular in shape, and a ball disposed in each bearing surface 4a1 (4b1) is rolled on the pitch circle PCD of the bearing surface 4a1 (4b1) following the eccentric rotation of a turning scroll member. This bearing ring 4a (4b) is formed to have no inner periphery without punching a center part. Thus, material yield is improved, and since no post-machining is necessary, machining is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust ball bearing which is interposed between two members, such as an orbiting scroll member and a stationary scroll member in a scroll compressor, which perform an eccentric rotary motion therebetween.

[0002]

2. Description of the Related Art For example, in a scroll compressor, as shown in FIG. 4, orbiting scroll member 11 and stationary scroll member 12 are provided with spiral partition walls 11b and 12b, respectively, and are formed between both spiral partition walls 11b and 12b. The compression chamber P
The volume of the orbiting scroll member 11 is changed with eccentric rotation with respect to the stationary scroll member 12, so that the fluid in the compression chamber P is compressed.

The axis of the orbiting scroll member 11 and the axis of the drive motor 15 are eccentric by the amount of eccentricity e. When the output shaft 15a of the drive motor 15 rotates, the orbiting scroll member 11 turns by the amount of eccentricity equal to the amount of eccentricity e. Eccentric rotation. At this time, a force is applied to the orbiting scroll member 11 to rotate the orbiting scroll member 11, and a thrust load accompanying the compressing operation of the fluid is applied. Therefore, in order to prevent the orbiting scroll member 11 from rotating and support a thrust load, the orbiting scroll member 11 and the stationary scroll member 12 (in the configuration shown in the drawing, the stationary frame 13 fixed to the stationary scroll member 12). A thrust ball bearing 14 is interposed between them.

The thrust ball bearing 14 comprises, for example, a pair of races 14a and 14b having the same shape, and the races 14a and 14b.
4b and a plurality of balls 14c interposed between them.
The orbital rings 14a, 14b are respectively fixed to mounting portions 11a, 13a of the orbiting scroll member 11 and the stationary frame 13 which are opposed to each other in the axial direction.

As shown in FIG. 5, the bearing ring 14a (14
b) is the inner circumference 14a2 (14b2) and the outer circumference 14a3 (1
4b3) is a circular ring, and a plurality of raceway surfaces 14a1 (14b1) are formed on the same circumference on one end surface thereof. Each raceway surface 14a1 (14b1) has an annular shape, and the balls 14c arranged on each raceway surface 14a1 (14b1) have a pitch circle of the raceway surface 14a1 (14b1) along with the eccentric rotation of the orbiting scroll member 11. Roll on the PCD. The diameter d of the pitch circle PCD of the raceway surface 14a1 (14b1) is equal to the eccentric amount e.

[0006]

The ring-shaped bearing ring as described above is usually formed by pressing a steel plate material, but the punched inner peripheral portion is discarded as it is. The usage rate of is low. Further, post-processing (burring, etc.) of the inner peripheral portion is also necessary. further,
This type of thrust ball bearing does not necessarily have to be ring-shaped in terms of its function, and it may be necessary to reexamine it from the viewpoint of effective utilization of the mounting space and increase of load capacity.

The present invention is intended to be improved in view of simplification of processing, effective utilization of mounting space, and increase of load capacity.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a pair of bearing rings, each of which is fixed to an axially opposed mounting portion of two members that perform eccentric rotary motion therebetween, and these bearing rings are formed. In a thrust ball bearing including a ball interposed between a plurality of formed raceway surfaces, a race ring is formed in a shape having no inner circumference.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a thrust ball bearing for a scroll compressor will be described below.

FIG. 1 shows a peripheral portion of a thrust ball bearing 4 in a scroll compressor. The orbiting scroll member 1 and the stationary frame 3 (the stationary frame 3 is fixed to the stationary scroll member 2).
a and 4b are respectively fixed by appropriate means {Fig. 1 (b)
Balls 4c are arranged between the plurality of raceway surfaces 4a1 and 4b1 formed on the pair of race rings 4a and 4b, respectively. It should be noted that the mounting portions 1a and 3a in this embodiment are not provided with a conventional annular shape, but are provided partially at one or more locations in the circumferential direction.

When the orbiting scroll member 1 eccentrically rotates with respect to the stationary scroll member 2 with an orbiting radius equal to the eccentric amount e, the volume of the compression chamber P formed between the spiral partition walls 1b and 2b changes. As a result, the fluid compression operation is performed. The thrust ball bearing 4 functions to prevent the orbiting scroll member 1 from rotating when such a compression operation is performed, and to support a thrust load.

FIG. 2 shows a bearing ring 4a on the turning side of the thrust ball bearing 4 (or a bearing ring 4b on the fixed side: the bearing ring 4a and the bearing ring 4b have the same shape). Bearing ring 4a (4
b) is formed by pressing, for example, from a steel plate material, and one end surface thereof has a plurality of concave raceway surfaces 4a1.
(4b1) is formed. Each track surface 4a1 (4b
1) is an annular shape, and each raceway surface 4a1 (4b)
The ball 4c arranged in 1) rolls on the pitch circle PCD of the raceway surface 4a1 (4b1) with the eccentric rotation of the orbiting scroll member 1. The diameter d of the pitch circle PCD of the raceway surface 4a1 (4b1) is equal to the eccentricity e.

The race ring 4a (4b) of this embodiment is different from the conventional one in that the center portion is not punched, that is, the shape has no inner circumference, and the race surface 4a1 ( 4b1) is formed.
Since the shape does not have an inner circumference, the material remains better than in the conventional form, and the post-processing (deburring, etc.) of the inner circumference is not necessary, so the processing is simplified. further,
Compared with the conventional ring-shaped bearing ring, it is possible to secure a wider space to install the raceway surface, so by increasing the number of raceway surfaces (the number of balls) and increasing the dimension of the raceway surface (ball diameter), It is possible to increase the load capacity. This also makes effective use of the mounting space.

In the embodiment shown in FIG. 3, the bearing ring 4a (4
The outer periphery of b) is a square shape. As can be understood from this embodiment, the bearing ring according to the present invention may have any shape as long as it has no inner circumference, and the shape of the outer circumference is not particularly limited. The shape of the outer circumference may be appropriately determined in consideration of the relationship with the mounting space and the like. For example, in addition to the illustrated circular shape, regular square shape, a polygonal shape such as a triangle, a rectangle, a trapezoid, a parallelogram, a hexagon, an ellipse, a star shape, and a tooth shape may be used. In addition, the outer circumference of the bearing ring 4a (4b) is made non-circular, and the periphery (shoulder portion) of the mounting portion 1a (3a) is made non-circular corresponding to this, and the outer circumference of the bearing ring 4a (4b) is mounted. The non-circular fitting around the portion 1a (3a) can prevent the bearing ring 4a (4b) from being displaced with respect to the mounting portion 1a (3a).

A plurality of paired mounting portions 1a, 3a are formed,
A thrust ball bearing 4 may be provided in each of them. Also,
INDUSTRIAL APPLICABILITY The present invention is not limited to thrust ball bearings for scroll compressors, and can be generally applied to thrust ball bearings that support a thrust load by being interposed between two members that perform eccentric rotary motion between them.

[0016]

As described above, according to the present invention,
Since the bearing ring has a shape without an inner circumference, the material is better retained than in the conventional form, and the post-processing (deburring, etc.) of the inner circumference is not necessary, so the processing is simplified. Furthermore, as compared to the conventional ring-shaped bearing ring, a larger space can be secured for the raceway surface, so the number of raceway surfaces (the number of balls) must be increased and the raceway surface dimensions (ball diameter) must be increased. This makes it possible to increase the load capacity. This also makes effective use of the mounting space.

[Brief description of drawings]

FIG. 1 is a sectional view (FIG. A) showing a peripheral portion of a thrust ball bearing in a scroll compressor, and a partially enlarged sectional view (FIG. B) of a thrust ball bearing.

FIG. 2 is a plan view showing a bearing ring.

FIG. 3 is a plan view showing another embodiment of the bearing ring.

FIG. 4 is a sectional view showing a general form of a scroll compressor.

FIG. 5 is a plan view showing a conventional bearing ring.

[Explanation of symbols]

 1 orbiting scroll member 1a mounting part 2 stationary school member 3 stationary frame 3a mounting part 4 thrust ball bearing 4a bearing ring 4b bearing ring 4c ball

Claims (1)

[Claims] 1. A pair of bearing rings, which are respectively fixed to mounting portions of two members that perform eccentric rotary motion between them, facing each other in the axial direction, and between a plurality of bearing surfaces formed on these bearing rings. A thrust ball bearing, characterized in that the bearing ring has a shape having no inner circumference.