A compressor shaft has a fluid inlet that leads into a fluid inlet tube, is perpendicular to a longitudinal hole in the length of the shaft. An intermediate inlet into the longitudinal hole is located between the fluid inlet and an outlet at an end of the longitudinal hole. A drive plate mounted to the compressor shaft has a protruding drive arm, which uses a holding mechanism to connect to a swash plate. At certain swash plate angles, the intermediate inlet is covered and sealed by the swash plate, or uncovered. The drive arm defines an internal bore and a through slot. At opposite ends, the bore merges into the longitudinal hole and open into the through slot. The holding mechanism and/or swash plate guide covers the bore in the slot.