Abstract: Aiming at the problem of high friction and easy mechanical collision of multi-degree-of-freedom motors using traditional joint bearings in three-dimensional motion, a multi-degree-of-freedom motor with a gas static pressure ball bearing instead of a conventional joint bearing was proposed. Comparing the characteristics of different gas static pressure ball bearings, porous gas static pressure ball bearings were selected. The mathematical model of the gas hydrostatic ball bearing and the COMSOL 3D simulation model were established. The accuracy of the analytical algorithm was verified by simulation calculation, and the influence of various parameters on the bearing capacity, air consumption and static stiffness of the bearing was further analyzed. The results indicate that the number of orifices, wrap angle and supply pressure have a direct impact on the performance of gas static ball bearings. The optimum distribution angle for the orifice is 32°. It provides a reference for the design of gas static pressure ball bearings and the application of multi-degree-of-freedom motors.
Key words: multi-degree-of-freedom motor; aerostatic ball bearing; mathematical model; bearing performance