Improving Rolling Element Bearing Thermal Compliance Through In Situ Cooling

In this study a novel in situ rolling element bearing (REB) lubricant cooling system is developed that provides a continuous cooling of the bearing outer race. In the design the stationary outer race is expanded to accommodate a cooling coil for the continuous cooling of the lubricant and the outer race. Water is used as the coolant While Amsoil 75W-90 Severe Gear® oil is used as a lubricant. Heat generated during the test run is removed by the coolant flowing through the cooling coil. The tribological effects at the speeds of the cooling test were evaluated using block-on-ring tribometer tests. Results from the experiments indicate that in the absence of cooling the temperature of the bearing outer race rises while cooling dramatically lowers the temperature. Also, the coefficient of friction increases with increasing speed. As such, in situ cooling that leads to reduced operational temperature minimizes lubricant degradation that can result from uncontrolled frictional heating.