JP2002039190A - Four-point contact ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a four-point contact ball bearing capable of preventing damage to a ball and separation at the bottom of a raceway groove to prevent an acoustic value from decreasing. SOLUTION: A raceway groove 1 having an elliptic cross section is formed in a raceway member 10. The ball rolls on a curved surface 2 which constitutes the raceway groove 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a four-point contact ball bearing.

[0002]

2. Description of the Related Art Conventionally, as a four-point contact ball bearing, as shown in FIG. 2, the radius of curvature of the cross-section of a raceway groove is made symmetrical with respect to the center of the bottom of the raceway groove, and the radius of curvature is reduced to a ball.
There is a track member 30 in which a track groove 21 having a substantially V-shaped cross section formed by two arcuate curved surfaces 22 and 23 having a diameter of 51.0 to 55% of the (ball) diameter is formed. Normally, the raceway groove is super-finished, but there is a portion at the bottom of the raceway surface where the grindstone of the super-finishing process does not slightly hit, and this portion is still rough.

[0003]

By the way, in a ball bearing for an electromagnetic clutch of a car air conditioner, an outer ring used for a rotation supporting portion of a compressor and an electromagnetic clutch rotates, and receives a radial load by a belt and a thrust load by an electromagnetic clutch. In addition, in the four-point contact ball bearing used for this, when the radial load is large, the ball (not shown) rolling on the curved surfaces 22 and 23 of the raceway groove 21 has elasticity. At the same time, the race is elastically deformed and the bottom 24 of the raceway groove 21 is deformed.
Contact with That is, the ball contacts the boundary between the two curved surfaces 22 and 23. Since this boundary portion is not super-finished and is not smooth, if the ball keeps rolling in contact with the boundary portion, the ball is damaged and the bottom 24 of the raceway groove 21 is peeled off. There was a problem that the value deteriorated.

An object of the present invention is to provide a four-point contact ball bearing which can prevent the ball from being damaged, prevent the bottom of the raceway groove from peeling off, and prevent the sound value from deteriorating.

[0005]

In order to achieve the above object, a four-point contact ball bearing according to the first aspect of the present invention is characterized in that the cross-section of each raceway of the inner and outer races is symmetrical with respect to the center of the bottom of the raceway groove as a boundary. It is characterized by a drawn ellipse, parabola or hyperbola.

According to the four-point contact ball bearing of the first aspect of the present invention, the cross-section of each raceway of the inner and outer races is an ellipse, a parabola, or a hyperbola symmetrical about the center of the bottom of the raceway groove. In addition, the shape of the grindstone becomes relatively simple, so that the bottom of the raceway groove can be easily super-finished. Therefore, the bottom of the raceway groove becomes smooth, and the ball rolls smoothly even if, for example, the ball contacts the bottom of the raceway portion. Therefore,
Even when the radial load increases and the ball comes into contact with the bottom of the raceway, damage to the ball can be prevented, separation of the raceway groove at the bottom can be prevented, and the acoustic value does not deteriorate.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a four-point contact ball bearing according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a schematic sectional view of a main part of a four-point contact ball bearing according to an embodiment of the present invention. As shown in FIG. 1, the four-point contact ball bearing has a raceway member 10 in which a raceway groove 1 having an elliptical cross section is formed. A ball (not shown) rolls on the curved surface 2 forming the raceway groove 1.

According to the four-point contact ball bearing having the above structure, since the raceway groove 1 is formed to have an elliptical cross section, machining of the raceway groove 1 by superfinishing becomes easy, and the bottom of the raceway groove 1 is formed. 4 becomes smooth. Therefore, even when the ball is elastically deformed at the time of a high radial load, the raceway ring is also elastically deformed and comes into contact with the bottom 4 of the raceway groove 1,
The ball rolls smoothly. As a result, the ball is not damaged, and further, the bottom 4 of the raceway groove 1 does not peel. Also, the sound value does not deteriorate.

In the above embodiment, the cross section of the raceway groove is elliptical, but it is sufficient if the cross section of the raceway groove is substantially elliptical. The cross section of the raceway groove may be parabolic or hyperbolic. Further, the track member 10 may be an inner ring or an outer ring.

[0011]

As is apparent from the above description, in the four-point contact ball bearing according to the first aspect of the present invention, the cross-section of each raceway of the inner and outer races is an ellipse symmetrical with respect to the center of the raceway bottom. As a result, the bottom of the raceway groove becomes smooth, which prevents the ball from rolling on the bottom of the raceway groove, for example, and prevents the bottom of the raceway groove from peeling off. Can be prevented from deteriorating.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a main part of a four-point contact ball bearing according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a main part of a conventional four-point contact ball bearing.

[Explanation of symbols]

 1 Track groove

Claims (1)

[Claims] 1. A four-point contact ball bearing wherein the cross-section of each raceway of the inner and outer races is an ellipse, parabola or hyperbola symmetrical about the center of the raceway bottom.