Design and operating characteristics of high-speed, small-bore cylindrical-roller bearings

The computer program SHABERTH was used to analyze 35-nun-bore cylindrical roller bearings designed and manufactured for high-speed turbomachinery applications. Parametric tests of the bearings were conducted on a high-speed, high-temperature bearing tester and the results were compared with the computer predictions. Bearings with a channeled inner ring were lubricated through the inner ring, while bearings with a channeled outer ring were lubricated with oil jets. Tests were nm with and without enter-ring cooling. The predicted bearing life decreased with increasing speed because of increased contact stresses caused by centrifugal load Lower temperatures, less roller skidding and lower power losses,were obtained with channeled inner rings. Power losses calculated by the SHABERTH computer program correlated reasonably well with the lest results. The Parker formula for XCAV (used in SHABERTH as a measure of oil volume in the bearing cavity) needed to be adjusted to reflect the prevailing operating conditions. The XCAV formula will need to be further refined to reflect roller bearing lubrication, ring design, cage design, and location of the cage-controlling land.