Abstract: A gas refrigerant compressor comprises a shaft having a first portion and an offset portion. A body supports the first portion of the shaft for rotating movement around an axis of rotation and defines a compression chamber. A compression member is adapted for reciprocating movement within the compression chamber. The compression member is connected to the offset portion of the shaft such that rotating the shaft draws gas refrigerant into the compression chamber upon movement of the compression member toward the axis of rotation and exhausts compressed gas refrigerant out of the compression chamber upon movement of the compression member away from the axis of rotation.