PURPOSE: To allow a constant amount of oil to be supplied irrespective of change in operational conditions of a compressor, by providing an adjustment passage made of shape memory materials having throttle mechanism serving to reduce passage resistance at an oil temperature lower than a predetermined temperature, on an upstream side of a differential pressure oil supply passage.

CONSTITUTION: Refrigerator oil temperature in an oil reservoir 8 is low just after a compressor is started to operate under cold condition, an opening degree of an adjustment passage 9 having a throttle mechanism made of shape memory materials on an upstream side of an oil suction passage 6 is large. Accordingly, refrigerator oil having high viscosity is fed through the adjustment passage 9, an oil supply passage 14, spaces 23 and 24, a shaft sealing space 15, a throttle passage 18 and a passage 17 on the suction side to a cylinder 12 by pressure differential between a discharge space 20 and the passage 17 on the suction side, and it sequentially lubricates slide surfaces on the way. On the other hand, the refrigerator oil temperature rises to a temperature higher than a predetermined temperature after continuation of operation or start under hot condition, a cross section of the adjustment passage 9 is restricted to be reduced. Therefore, the flow quantity of the refrigerator oil which has low viscosity and accordingly is readily flowable is restricted, resulting in supply of a fixed amount of oil at all times.