Research Status and Prospect of Self-Lubricating Fabric Composites and Their Applications in Self-Lubricating Spherical Plain Bearings

The self-lubricating spherical plain bearing is a kind of spherical plain bearing with special structure, and its sliding contact surface is composed of the outer sphere of the inner ring and the inner sphere of the outer ring. The self-lubricating function of the bearings is mainly realized by spraying, plating or bonding solid lubricating materials on the moving surface of bearings. Due to their simple structure, strong load-bearing capacity, high reliability, wear resistance, low friction and maintenance-free performance (no grease required) , self-lubricating spherical plain bearings are widely used in aviation, aerospace, ships, national defense equipment, heavy machinery, industrial equipment and other fields . In the field of aviation, self-lubricating spherical plain bearings are very important components in key motion systems such as fixed-wing aircraft landing gear system, flaperon, helicopter rotor system and difficult maintenance position of aircraft engine. In space equipment, self-lubricating spherical plain bearing are used in robotic arms, hatch doors, antennas and other moving mechanisms of space station and satellite equipment. In the automotive industry, bearings are mainly used in the suspension system to reduce the friction of the suspension system and improve the stability and comfort of the suspension. In the field of heavy machinery and equipment, self-lubricating spherical plain bearing are mainly used in joints and joint parts of industrial robots, hydraulic generators, turbines and mining machinery to reduce friction and extend maintenance cycle. However, with the continuous improvement of the ultimate performance of the above equipment, higher and higher requirements are put forward for the service life, reliability and tribological performance of self-lubricating spherical plain bearing. The performance of self-lubricating materials between the inner and outer rings of bearings has a very important impact on the service performance and reliability of joint bearings, mainly including metal matrix composite materials, solid self-lubricating coatings/films, reinforced polymers and self-lubricating fiber fabric materials .

This article starting from a tribological perspective, summarized the current research on self-lubricating fibrous composite materials used in self-lubricating spherical plain bearings. This included enhanced fibers, weaving processes, test conditions, function-enhancing materials and fiber-resin interface modifications. Additionally, the article introduced the life evaluation of self-lubricating plain bearings, covering bearing test specifications and product standards, bearing life testing and prediction, as well as factors influencing bearing life and reliability. Finally, it provided an outlook on the future key research directions for fibrous composite self-lubricating lining materials and self-lubricating spherical plain bearings.