The Balance of Rollers for High DN Bearings
Abstract
A gas bearing spin-up device has been built for determining the residual unbalance remaining in rollers for high speed bearing applications after the rollers have successfully completed the manufacturing and final inspection process. The device has successfully determined the mean unbalance in a group of 30 rollers to be in the range of .000005 to .0000056 in.-oz. per end with a standard deviation in the range of .0000027 to .0000033 in.-oz. The spin- up device uses capacitance type non-contacting sensors to measure the roller's response. The measurement resolution has been determined to be .000002 inch and its sensitivity approximately 250 volt/inch. For the roller investigated, the minimum measurable unbalance is approximately .000005 in.-oz. In a second phase of this study, a complement of 32 rollers, screened for minimum unbalance in the balancing fixture, was assembled into a zero radial clearance bearing which was then tested to 2.5 million DN under a 500-lb. radial load. At the conclusion of 4o test hours, four of the rollers in the above bearing were replaced with four new rollers which were deliberately unbalanced. An additional 40 test hours at 2.5 million DN and 500-lb. radial load were logged with no visible effects caused by the roller unbalance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 28, 1978
- Accession Number
- ADA065899
Entities
People
- Martin Eusepi
- Pradeep Gupta