Thermal Conductance Measurement Techniques for High-Speed Bearings in Vacuum

An experimental method has been developed at The Aerospace Corporation to determine the thermal conductance of moving bearings in vacuum. The test involves the measurement of thermal conductance of a single bearing under controlled inner race rotational speed, axial load, and thermal environment. Applications of interest include high-speed momentum wheels and flywheels. This paper covers the experimental method developed for this purpose and the techniques used to establish measurement uncertainty.