(1) anti-friction wear, reduce friction in order to save energy, reduce wear to extend the mechanical life and increase economic efficiency.
(2) cooling, required to keep the friction heat from the plane.
(3) sealed to prevent leakage requirements,dust,gas string.
(4) anti-corrosion rust,friction surface for protection from foreign oil deterioration or erosion.
(5) clean washing, cleaning requirements to eliminate the friction area of scale.
(6) The stress buffer dispersed, decentralized load and ease the shock and vibration.
(7) the kinetic energy transmission, hydraulic system and remote control variable speed motors and friction and so on.
