da Silva, L., Tessari, K., Privatti, M., Wagner, A. et al., "Torque-Speed-Temperature Relationship in Grease Lubricated Angular Contact Ball Bearings," SAE Technical Paper 2015-36-0234, 2015, doi:10.4271/2015-36-0234.
High friction often involves high wear and power loss. The speed-temperature-dependence of grease lubricated contact ball bearings showed a variety of effects. The test apparatus is an axially-loaded angular contact ball bearing instrumented to measure the frictional torque as well as the transient temperature of the raceway. Effects of friction torque were examined at different speeds, operating temperatures and greases. Torque measurements and transient temperatures were compared for each grease, depending on the operating conditions. After experimental results, the grease formulation under different operation temperatures and different speeds showed significant influence on starting and rotating torques. Moreover the torque showed significant increase during the angular acceleration phase and decreased rapidly after the speed stabilization in all investigated greases.