PURPOSE: To aim at enhancing the volumetric efficiency of a closed type rotary compressor and at reducing the compression power thereof, by reducing gaps at the upper and lower end faces of a roller with the use of pressure differential between discharge pressure and suction pressure which act to a roller retaining plate facing a suction chamber, so that coolant gas leakage to the suction chamber and a discharge chamber is prevented.

CONSTITUTION: Since discharge gas of high pressure in a casing 1 is led to a pressure groove 21 through a communication hole 22, a roller retaining plate 16 of thin plate structure facing a suction chamber 11 is pushed to a roller 8 by differential pressure between discharge pressure and suction pressure. Further, the roller 8 is maintained to be pushed since the differential pressure is similarly produced until the pressure a discharge chamber 10 reaches the discharge pressure. Thereby, gaps at the upper and lower end faces of the roller 8 are reduced, and therefore, leakage from a lateral chamber 12 in the roller 8 to the suction chamber 11 and the discharge chamber 10 may be prevented so that the performance of the compressor is enhanced. Further, a check valve 18 is integrally incorporated with the roller retaining plate 16, and therefore, its structure is simplified.