# US 4,398,778 A · Ball bearing

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- Number: US 4,398,778 A
- Document ID: US4398778A
- Status: Granted
- Kind: A
- Application number: 06/246,862
- Filed: 1981-03-23
- Granted: 1983-08-16
- Earliest claimed: 1980-11-10
- Assignees: Excelermatic Inc.
- Inventors: Charles E. Kraus
- Web page: https://patentgrep.com/patent/US4398778A

## CPC

- F16C 19/163: {with angular contact}
- F16C 19/10: for axial load mainly
- F16C 33/585: {of raceways, e.g. ribs to guide the rollers}
- F16H 15/38: with two members B having hollow toroid surfaces opposite to each other, the member or members A being adjustably mounted between the surfaces
- F16C 2240/30: Angles, e.g. inclinations
- F16C 2240/34: Contact angles
- F16C 2240/76: Osculation, i.e. relation between radii of balls and raceway groove
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16H: GEARING

## Abstract

An axial thrust bearing includes two race rings with opposed race surfaces defining a ball cavity and balls disposed in the ball cavity for rotatably supporting the race rings relative to each other. At least one of the race surfaces has annular raised areas which provide for rolling contact areas for the balls, the annular contact areas of the races being arranged in low speed bearings such that the apexes of the cones defined by the annular contact areas coincide on the axis of the bearing. In high speed bearings the races are arranged so that secants through the ball and race contact points form an angle with a plane normal to the bearing axis, which angle is between 40 and 20% of an ideal angle at which the secants intersect on the bearing axis. With this arrangement two rolling contact areas are provided by the respective race which increases load capacity and life of the respective race and reduces friction.

## Claims

### Claim 1

A high speed axial thrust bearing comprising two race rings with opposed race surfaces forming a bearing cavity therebetween, and bearing balls disposed within said cavity so as to rotatably support said race rings relative to each other, said race rings each having two races each with two circular contact areas with said rollers for supporting said rollers, said races being so arranged that secants through the ball and race contact points form an angle .beta.' with a plane normal to the bearing axis which angle .beta.' is between 40% and 20% of the ideal angle .beta. at which the secants intersect on the bearing axis.

### Claim 2 (depends on 1)

An axial thrust bearing as recited in claim 1, wherein an angle .alpha. which is half the angle between the connecting lines of the center of a bearing ball and the two points of contact of the bearing ball with one of the race rings is between 16.degree. and 26.degree..

### Claim 3 (depends on 2)

A bearing as recited in claim 2, wherein said angle .alpha. is 18.degree.-22.degree..

### Claim 4 (depends on 1, 2)

A bearing as recited in claim 1 or 2, wherein said race surfaces are formed by an annular cavity in the race rings which annular cavity, in cross-section, has a radius of basic curvature larger than the radius of the balls of said bearing and an annular recess in said annular cavity, said annular recess having, in cross-section, a curvature with a radius smaller than that of said balls so as to form said contact areas at the limits of said annular recess.

### Claim 5 (depends on 1, 2)

A bearing as recited in claim 1 or 2, wherein said race surface is formed by an annular cavity in the race rings which annular cavity in at least one of the race rings is defined by two annular surface areas disposed at an angle with respect to each other and each having, in cross-section, a radius of curvature larger than the radius of said ball, such that an annular recess is formed at the juncture of said surfaces, said balls contacting both annular surface areas.