GB2058243A

GB2058243A - Deep groove ball bearing

Info

Publication number: GB2058243A
Application number: GB8022056A
Authority: GB
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 1979-07-05
Filing date: 1980-07-04
Publication date: 1981-04-08
Also published as: JPS5610516U; FR2461149A1; FR2461149B1; GB2058243B; DE3023811A1

Abstract

In a deep groove ball bearing having balls disposed between the deep groove orbit of an outer race and the deep groove orbit of an inner race, the groove depth h1 of the orbit of the outer race, the groove depth h2 of the orbit of the inner race and the diameter d of the balls satisfy the relation that h1 + h2 >/= d/2. A method of assembly is described (Fig. 2) wherein the inner race is first coated and interdigitated with the outer race, the balls are inserted, and after aligning the inner race and distributing the balls, a cage is applied. <IMAGE>

Description

SPECIFICATION Deep groove ball bearing Background of the Invention Field of the Invention This invention relates to improvements in a deep groove ball bearing.

Description of the PriorArt As regards the groove depths of the orbits of the heretofore known deep groove ball bearing, the groove depth of the orbit of the outer race has been substantially equal to the groove depth of the orbit of the inner race and the sum of these groove depths has been smaller than the radius of balls used (the balls arranged between the outer race and the inner race). Therefore, when a great thrust load or moment load has been applied to the bearing, there has been a problem that the balls ride onto the shoulder of the orbit (the end portion of the curved surface of the orbit) to cause edge striking and thus cannot take a sufficient load and damages the bearing too early.

Summary of the Invention It is an object of the present invention to eliminate the above-noted problem peculiar to the deep groove ball bearing of the prior art.

The present invention provides a deep groove ball bearing in which the orbit groove depth h1 of the outer race, the orbit groove depth h2 of the inner race and the diameter d of the balls satisfy the relation that h1 + h2 ~ d/2.

Thus, in the deep groove ball bearing of the present invention, the sum of the groove depths of the outer race and inner race is made equal to or greater than the radius (1/2 of the diameter) of the balls and therefore, the bearing effective acts for a radial load as well as for a thrust load and a moment load and the life of the bearing can be extended remarkably. Particularly, where the groove depth of the inner race is made great relative to the groove depth of the outer race, the effect is more pronounced.

However, if the sum of the groove depths of the outer race and inner race is too great relative to the diameter of the balls, the assembly of the bearing will become difficult. Therefore, when the assembly of the bearing is taken into account, the groove depths of the outer race and inner race should preferably satisfy the relation that h1 + h2 < 0.75d. If the sum h1 + h2 of the groove depths exceeds 0.75 d, it will be necessary to provide a ball insertion cut-away in the groove shoulder of the outer race or the inner race and to close the cut-away after insertion of the balls, and this not only makes the assembly of the bearing difficult but also is not preferable to the strength and life of the bearing.

The invention will become more fully apparent from the following detailed description thereof taken in conjunction with the accompanying drawings.

Brief Description of the Drawings Figure 1 is a longitudinal cross-sectional side view showing an embodiment of the deep groove ball bearing of the present invention.

Figure 2 illustrates the combination of the races and a ball.

Description of the Preferred Embodiment The present invention will hereinafter be described with respect to a preferred embodiment thereof shown in Figures 1 and 2. Reference numeral 1 designates an outer race of a deep groove ball bearing, reference numeral 2 denotes an inner race, reference numeral 3 designates a ball, reference numeral 4 denotes a retainer, and reference numeral 5 designates a seal member.

The outer race 1 has a deep groove-shaped curved orbit 11. The groove depth h1 of the curved orbit 11 is slightly greater than one half (d/4) of one half (radius) of the diameter d of the ball, and the groove depth h2 of the curved orbit of the inner race 2 is also slightly greater than 1/4 of the diameter of the ball 3. That is, the sum (H + h2) of the groove depth of the orbit of the outer race and the groove depth of the orbit of the inner race is greater than one half (d/2) of the diameter d of the ball 3. Particularly, h1 and h2 in the present embodiment are in the relation that h1 < h2.

As regards the thus formed outer race 1 and inner race .2, as shown in Figure 2, for example, the inner race 2 is inclined with respect to the outer race 1 and is brought near one side, the groove shoulder of the inner race 2 is brought close to or into contact with the substantially central portion of the groove bottom of the outer race 1 to create on the outer side an interval I necessary for placing balls therein, a required number of balls 3 are inserted through said interval, whereafter the inserted balls 3 are arranged substantially equidistantly between the orbits of the outer and inner races, and then the retainer 4 is assembled to the outer and inner races, thus providing the bearing of the present invention.

As the result of an experiment carried out for three types of bearings, i.e., a bearing in which h1 is 26% of d and h2 is 28% of d, a bearing in which h1 is 29% of d and h2 is 34% of d, and a bearing in which h1 is 32% of d and h2 is 40% of d, it has been found that greater groove depths with the relation to the combination taken into account is more effective in the life of the bearing, and the sum of said groove depths exceeding 60% of d is more effective than the sum less than 60% and provides ten times the life of conventional bearings.

While the embodiment has been described with an example of the usual deep groove ball bearing, the present invention is equally applicable, for example, to flanged bearings having mounting flanges on the outer race and inner race, bearings for combination with machine parts having bearing orbits formed in a portion thereof, or full type ball bearings having no retainer. Especially, when the present invention is applied to the full type ball bearing, ball insertion holes or grooves are provided in one or both of the outer and inner races from the viewpoint of the combination between the outer race, the inner race and balls.

The invention may sometimes be carried out with the groove depth of the inner race being equal to the groove depth of the outer race, and further, the aforementioned curved orbit may be formed as an arcuate surface having a single radius slightly greater than the radius of the balls, or formed as a quadratic surface having a curvature gradually varying from the groove bottom toward the groove shoulder and thus, the curved surface configuration of the groove is not specifically restricted.

Also, when the inner and outer races are assembied together eccentrically with each other with their shoulders fitted in their respective corresponding grooves as shown in Figure 2, the groove depths can be made great to such an extent that one of 2h2 + h1 and 2h, + h2 which is greater is nearly equal to 1.13d.

Claims

1. In a deep groove ball bearing having balls disposed between the deep groove orbit of an outer race and the deep groove orbit of an inner race, the improvement residing in that the relation among the groove depth h1 of the orbit of said outer race, the groove depth h2 of the orbit of said inner race and the diameter d of said balls is h, + h2 ~ d/2.

2. A deep groove ball bearing according to Claim 1, further satisfying the relation that h, + h2 < 0.75d.

3. A deep groove ball bearing, substantially as herein described with reference to the accompanying drawings.