Effect of Cavity Shapes on the Lubrication Performance of High Precision Static and Dynamic Thrust Bearing Under Eccentric Load

Abstract The oil cavity shapes, which represent the spatial structures for storing lubricant in static and dynamic thrust bearings, and offset distances, defined as the horizontal distances between the load center and the bearing rotational axis under eccentric loads, directly impact the flow mode of lubricant, pressure, and temperature distribution during bearing operation, so these are the key factors that influence the lubrication performance and the accuracy of bearings. The equations for flow and load-carrying capacity of the sector, runway, and double rectangular cavities are derived, and mathematical models are established for different cavities at various tilt positions. Then pressure and temperature fields at different offset distances are analyzed. As the offset distances increase, there is a corresponding increase in the maximum pressures within the sector, runway, and double rectangular cavities by 90.5 kPa, 93.3 kPa, and 30.9 kPa, but average pressures show only minor fluctuations. Concurrently, the maximum temperatures within these cavity shapes are observed to increase by 0.5 K, 0.6 K, and 0.8 K, respectively. The results show that appropriate offset distance can improve the lubrication performance. The runway cavity has the highest load-carrying capacity among the three cavity shapes, while the sector cavity experiences the slightest temperature increase. As the temperature increase in all three cavity shapes is small, the runway cavity exhibits superior performance. The error between simulation and experimental results is less than 10%, which verifies the correctness of the simulation method.