JPH09273545A - Thrust ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with additional provision of a rotation preventive means of an orbit ring. SOLUTION: An inner periphery 4a2 of an orbit ring 4a has a non-circular shape such as square shape, while an outer periphery 4a3 has a circular shape. A shoulder 1a1 of an installation part 1a of a scroll member 1 has the shape of, for instance, square shape correspondingly to the inner periphery 4a2 of the orbit ring 4a. In order to install the orbit ring 4a to the installation part 1a, the square inner periphery 4a2 of the orbit ring 4a is fitted to the square shoulder 1a1 of the installation part 1a.

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 interposed between two members, such as a revolving scroll member and a stationary scroll member, which perform an eccentric rotational movement between them, such as a scroll compressor.

[0002]

2. Description of the Related Art For example, in a scroll compressor, as shown in FIG. 7, orbiting scroll member 11 and stationary scroll member 12 are provided with spiral partition walls 11b and 12b, respectively.
Compression chamber P formed between both spiral partition walls 11b, 12b
To the stationary scroll member 12 of the orbiting scroll member 11
By changing the volume with eccentric rotation to
The compression operation of the fluid in the compression chamber P is performed.

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. 8, 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 bearing ring 14a (14)
b) is the inner circumference 14a2 (14b2) or the outer circumference 14a3 (1
4b3) or the inner periphery 14a2 (14b2) and the outer periphery 14a3 (14b3) respectively corresponding to the mounting portion 1
It is circularly fitted to the shoulder portion of 1a (13a), and is further fixed to the mounting portion 11a (13a) by rotation preventing means such as pin engagement, concave-convex engagement, and caulking. It is necessary to additionally provide such a rotation stopping means because the orbital ring 14a (14) is accompanied by the eccentric rotation of the orbiting scroll member 11.
This is because a force that causes b) to rotate about the mounting portion 11a (13a) is generated.

[0007]

SUMMARY OF THE INVENTION In order to separately provide the above-mentioned rotation stopping means, a pin hole, a notch,
Although it is necessary to provide a caulking allowance, it is often difficult to secure a space therefor due to dimensional restrictions.
Further, in order to secure a space under dimensional constraints, it becomes necessary to reduce the ball diameter and the number of raceway surfaces to be formed, so that the bearing function is sacrificed. Further, there is a problem that the assembling work becomes complicated.

The present invention is intended to solve the above-mentioned problems by eliminating the need for the rotation preventing means of the bearing ring in the conventional structure.

[0009]

DISCLOSURE OF THE INVENTION A thrust ball bearing of the present invention comprises a pair of bearing rings, which are respectively fixed to axially opposed mounting portions of two members which perform eccentric rotary motion therebetween. And a ball interposed between raceway surfaces formed on the raceway ring, and at least one of the raceway rings has an inner circumference or an outer circumference, or an inner circumference and an outer circumference that are non-circularly fitted to the mounting portion.

Further, the thrust ball bearing of the present invention comprises a pair of bearing rings axially opposed to each other, and balls interposed between the bearing surfaces formed on these bearing rings, and at least one bearing ring. The inner circumference or the outer circumference, or the inner circumference and the outer circumference is non-circular.

The term "non-circular shape" as used herein includes not only polygonal shapes such as triangles, squares and hexagons but also all shapes other than circular shapes such as elliptical shapes, spherical surfaces and tooth shapes. Further, "non-circular fitting" refers to a state in which the inner circumference and the outer circumference of two members having various shapes as described above are shape-fitted to each other and are fitted to each other.

[0012]

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 as shown in FIG. The orbiting scroll member 1 and the stationary frame 3 (the stationary frame 3
Is fixed to the stationary scroll member 2. ), The pair of bearing rings 4a, 4b of the thrust ball bearing 4 are respectively fixed to the mounting portions 1a, 3a facing each other in the axial direction, and the plurality of bearing surfaces 4a1, 4b1 formed on the pair of bearing rings 4a, 4b. Balls 4c are arranged between them. 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, and Compression operation is performed. Thrust ball bearing 4
Serves to prevent the orbiting scroll member 1 from rotating when such a compression operation is performed and to support the thrust load.

As shown in an enlarged view in FIG. 1B, in this embodiment, the mounting portions 1a and 3a are both step-shaped, and the inner circumference 4a2 of the orbiting wheel 4a on the turning side is the shoulder of the mounting portion 1a. The outer circumference 4b2 of the bearing ring 4b on the stationary side fitted to the portion 1a1
Is fitted to the shoulder portion 3a1 of the mounting portion 3a.

FIG. 2 illustrates the orbiting wheel 4a on the turning side. The bearing ring 4a is formed, for example, from a steel plate material by pressing or the like, and a plurality of concave raceway surfaces 4a1 are formed on the same circumference on one end face thereof. Each orbital plane 4
a1 has an annular shape, and the balls 4c arranged on each raceway surface 4a1 roll on the pitch circle PCD of the raceway surface 4a1 as the orbiting scroll member 1 eccentrically rotates. The diameter d of the pitch circle PCD of the raceway surface 4a1 is equal to the eccentric amount e. The inner circumference 4a2 of the bearing ring 4a has a non-circular shape, for example, a square shape, and the outer circumference 4a3 has a circular shape.

Further, as shown in FIG. 3, the shoulder portion 1a1 of the mounting portion 1a of the scroll member 1 is also formed in a non-circular shape, for example, a quadrangular shape, corresponding to the inner circumference 4a2 of the bearing ring 4a. When mounting the bearing ring 4a on the mounting portion 1a, the quadrangular inner circumference 4a2 of the bearing ring 4a is fitted to the quadrangular shoulder portion 1a1 of the mounting portion 1a. In this way, the inner circumference 4a2 of the bearing ring 4a is non-circularly fitted to the shoulder portion 1a1 of the mounting portion 1a, so that the bearing ring 4a is prevented from rotating with respect to the orbiting scroll member 1. Therefore, it is not necessary to separately provide the rotation stopping means as in the conventional case.

The embodiment shown in FIG. 4 has a bearing ring 4 on the turning side.
The inner circumference 4a2 of a is formed into an elliptical shape. Bearing ring 4a
The shoulder portion 1a1 of the mounting portion 1a of the orbiting scroll member 1 is also formed in an elliptical shape so as to correspond to the inner circumference 4a2 of the orbiting scroll member 1, and both are fitted in a non-circular shape.

FIG. 5 illustrates the bearing ring 4b on the stationary side. The bearing ring 4b is also formed, for example, by pressing from a steel plate material, and a plurality of concave raceway surfaces 4b1 is formed on one end face thereof on the same circumference and in phase with the raceway surface 4a1 of the turning side raceway 4a. It is formed in the same way. Each raceway surface 4b1 has an annular shape, and the balls 4c arranged on each raceway surface 4b1 roll on the pitch circle PCD of the raceway surface 4b1 with the eccentric rotation of the orbiting scroll member 1.
The diameter d of the pitch circle PCD of the raceway surface 4b1 is equal to the eccentric amount e. The outer circumference 4b2 of the bearing ring 4b has a non-circular shape, for example, a square shape, and the inner circumference 4b3 has a circular shape. Although not shown, the shoulder portion 3a1 of the mounting portion 3a of the stationary frame 3 is also formed in a non-circular shape, for example, a quadrangular shape, corresponding to the outer circumference 4b2 of the bearing ring 4b. When mounting the bearing ring 4b on the mounting portion 3a, the rectangular outer periphery 4b2 of the bearing ring 4b is
It fits into the rectangular shoulder 3a1 of the mounting portion 3a. In this way, the outer circumference 4b2 of the bearing ring 4b is non-circularly fitted to the shoulder portion 3a1 of the mounting portion 3a, so that the bearing ring 4b is prevented from rotating with respect to the stationary frame 3 (and the stationary scroll member 2). Therefore, it is not necessary to separately provide the rotation stopping means as in the conventional case.

In the embodiment shown in FIG. 6, the inner circumference 4a2 (4b3) and the outer circumference 4a3 (4b2) of the bearing ring 4a (or / and bearing ring 4b) are made non-circular, for example, quadrangular. Inner circumference 4a2 of bearing ring 4a (outer circumference 4 of bearing ring 4b
b2) is non-circularly fitted to the shoulder portion 1a1 of the mounting portion 1a of the orbiting scroll member 1 (shoulder portion 3a1 of the mounting portion 3a of the stationary frame 3) in the manner described above. Turning side bearing ring 4a
Since the bearing ring 4b on the stationary side can have the same shape, the manufacturing process, the assembly process, and the parts management can be simplified.

The non-circular fitting detent may be applied to at least one of the orbiting ring 4a and the stationary ring 4b. In addition, such non-circular fitting is not limited to the square fitting and the elliptical fitting described above, but various non-circular fitting structures such as triangular fitting and hexagonal fitting should be adopted. You can Further, when the mounting portion is not the stepped shape exemplified above but an annular groove shape (a shape having shoulder portions on the inner diameter side and the outer diameter side respectively), both the inner and outer circumferences of the bearing ring are annular groove shape. You may make it fit non-circularly to each shoulder part of the mounting part. Further, the stationary side mounting portion may be formed as a stationary scroll member. The present invention is not limited to thrust ball bearings for scroll compressors, but is interposed between two members that perform eccentric rotary motion between them,
It can be generally applied to thrust ball bearings that support thrust loads.

[0021]

As described above, according to the present invention,
Since it is not necessary to separately provide a rotation preventing means such as pin engagement, concave-convex engagement, and caulking in the conventional configuration, it is easy to deal with cases where dimensional restrictions are severe, and there is also a concern that the bearing function will deteriorate. Absent. Further, since it is not necessary to separately provide the rotation stopping means, the bearing size can be reduced. Further, the assembling work is also simplified.

[Brief description of drawings]

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

FIG. 2 is a plan view showing a bearing ring on a turning side.

FIG. 3 is a perspective view showing how the orbiting wheel on the turning side is attached.

FIG. 4 is a plan view showing a bearing ring according to another embodiment.

FIG. 5 is a plan view showing a bearing ring according to another embodiment.

FIG. 6 is a plan view showing a bearing ring according to another embodiment.

FIG. 7 is a perspective view showing one form of a scroll compressor.

FIG. 8 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 (2)

[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 are interposed between the bearing surfaces formed on these bearing rings. A thrust ball bearing comprising: a ball, wherein at least one of the bearing rings has an inner circumference or an outer circumference, or an inner circumference and an outer circumference fitted to the mounting portion in a non-circular shape. 2. A pair of raceways arranged to face each other in the axial direction, and balls interposed between raceway surfaces formed on these races, wherein at least one of the races has an inner circumference or an outer circumference, or A thrust ball bearing characterized in that the inner circumference and the outer circumference are non-circular.