Original Date: 04/26/1999
Revision Date: 01/18/2007

Cryogenic bearing testing requires special requirements such as bearing test rigs to duplicate cryogenic turbopump conditions, and computer modeling codes to design special bearings. In the early 1980s, Marshall Space Flight Center (MSFC) formed a multi-discipline team consisting of experts in tribology, design, test, materials, and fabrication to initiate a Bearing Test program. The team addressed the cryogenic requirements, fabricated a test rig, and began testing. Contracts were also awarded to companies to design low friction lubricating cages, develop better bearing materials, and refine the bearing modeling codes.

MSFC’s Bearing Test program fostered many advancements such as improved bearing materials. New low friction lubricating cages consisting of LOX compatible oils, carbon composite cages, and Salox cage inserts were also developed. Test results led to a better understanding of heat generation, hertzian stresses, wear life factors, dynamics of elements, and internal geometry changes. This information was incorporated into the computer bearing design codes of SHABERTH/SINDA, ADORE, and AB JONES.

Future turbopumps will spin faster and require more power, and the new hydrostatic bearings are well suited for this application. MSFC also designed and built a test rig that can run hydrostatic bearings and, with modifications, can run rolling element bearings in liquid nitrogen, liquid oxygen, and liquid hydrogen (LH2). The LH2 testing capability is unique to MSFC. Although it was not directly related to manufacturing, the Bearing Test program led to new bearing technologies and improved computer-modeling codes for these types of bearings. Applications for this technology include aerospace bearings, high-speed spindle bearings, industrial air conditioning, and high-speed turbo vacuum pumps.

For more information see the Point of Contact for this survey.