Design of oil recess depth for enhanced hydrostatic bearing lubrication characteristics

The oil recess depth influences the oil film pressure, temperature, velocity, and load-carrying capacity. An optimal oil recess depth enhances machining accuracy and operational stability of Computer Numerical Control equipment. Based on lubrication theory and tribological principles, this paper systematically analyzes how the oil recess depth influences the lubrication characteristics of the hydrostatic thrust bearing, and analyzes the influence of the oil recess depth on the oil film pressure, oil film temperature, and oil film velocity, in order to determine the optimal oil recess depth. The relationship between recess depth and lubrication characteristics is established. Through simulation analysis, it was found that when the depth of the oil recess is 3.5 mm, the maximum pressure of the oil recess is 46092.8 Pa and the temperature is 338.3 K. An oil recess depth test bench is established, and experiments are carried out based on the simulation conditions for verification. The experimental results show that in the hydrostatic thrust bearing, a depth of 3.5 mm can achieve the maximum load-bearing capacity and the lowest oil film temperature, thereby obtaining the optimal lubrication characteristics. These theoretical calculations show excellent agreement with experimental measurements. These findings establish a theoretical foundation for the development of larger-tonnage hydrostatic thrust bearings in the future, significantly contributing to enhanced operational stability in Computer Numerical Control machining equipment.