Ceramic Rail-Race Ball Bearings
- Saturday, 01 May 2010
These bearings would tolerate dust better than conventional ball bearings.
Non-lubricated ball bearings featuring rail races have been proposed for use in mechanisms that are required to function in the presence of mineral dust particles in very low-pressure, dry environments with extended life. Like a conventional ball bearing, the proposed bearing would include an inner and an outer ring separated by balls in rolling contact with the races. However, unlike a conventional ball bearing, the balls would not roll in semi-circular or gothic arch race grooves in the rings: instead, the races would be shaped to form two or more rails (see figure). During operation, the motion of the balls would push dust particles into the spaces between the rails where the particles could not generate rolling resistance for the balls.
The rail and ball materials must have very high compressive strength, hardness, and wear resistance in order for the rail-race bearing to have a reasonable load capacity and be able to operate in the presence of the dust particles with minimal wear. Preferably, both the rails and the balls would be made of ceramics identical or similar to those now used in some commercially available bearings. These ceramics have strengths and hardnesses greater than those of the dust particles. The rails would be integral with the rings and formed by grinding ceramic ring blanks.
This work was done by Mark A. Balzer, Greg S. Mungas, and Gregory H. Peters of Caltech for NASA’s Jet Propulsion Laboratory.
In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:
Innovative Technology Assets Management
Mail Stop 202-233
4800 Oak Grove Drive
Pasadena, CA 91109-8099
Refer to NPO-44908, volume and number of this NASA Tech Briefs issue, and the page number.