1) lubrication. It can lubricate the compressor moving parts surface, reducing drag and friction, lower power consumption and prolong life. 2) a cooling effect. It timely away the heat generated by friction moving surface, preventing the compressor temperature is too high or the compressor is burned. 3) seal. Lubricants penetrate the sealing surface of each friction member is formed seals, play to prevent refrigerant leakage effect. 4) reduce the compressor noise. Lubricants and continue washing friction surface, remove debris, to reduce friction and wear parts.