High-Speed Floating-Ring Bearing Test and Analysis

Abstract

Testing of small high-speed floating-ring bearings, typical of those used in automotive turbochargers, revealed a discrepancy between ring speed measurements and ring speed prediction using isothermal bearing analysis. As bearing stability, energy loss, and load capacity are dependent on ring speed, an experimental program was undertaken to determine the effects of various bearing parameters on ring speed. The program results show that none of the 16 bearing parameters investigated increased the bearing ring speeds to those values predicted by the isothermal bearing analysis. In parallel with the experimental program, a thermal analysis was developed in which the effects of lubricant and bearing temperature on the ring speed of a floating-ring bearing way investigated. The ring speed predictions from this thermal floating-ring bearing model agree with the measured values except at the lowest and highest speeds tested. Therefore, for the type of floating-ring bearing design described in this paper, it is concluded that thermal heating can contribute significantly to ring-speed reduction.