Joint bearings, also known as spherical sliding bearings, consist of an outer ring and an inner ring. The outer ring has an inner spherical surface and the inner ring has an outer spherical surface. The sliding contact surface is treated with phosphating, blasting, padding, spraying, etc., and is equipped with lubrication holes and grooves [3-4]. It reduces lubrication dependence through composite material or PTFE fabric self-lubricating pad technology, and has the characteristics of high load capacity, impact resistance, corrosion resistance, wear resistance, etc. It can achieve multi-directional loads and certain angle rotation. This bearing is suitable for low-speed swing and multi-directional motion, can compensate for misalignment and withstand deformation of surrounding components, and is widely used in engineering machinery, automotive shock absorbers, water conservancy equipment, medical prosthetics, surgical robots, and humanoid robots [2-3] [6-7]. The classification covers centripetal, angular contact, thrust, rod end and other types, among which angular contact spherical sliding bearings can withstand combined radial and axial loads [1] [3]. Domestic enterprise Longxi Co., Ltd. independently developed PTFE fabric self-lubricating pads, which are used in domestic large aircraft C919 and aerospace engineering, and have the highest global market share [5] [7].
