The cylinder body is connected with the spline on the main shaft so as to rotate together with the main shaft. The plunger assembly is installed inside the cylinder that moves with the swash plate, and the plunger moves from the bottom dead center to the top dead center and moves in the direction of increasing outlet flow. After the hydraulic oil passes through the oil suction port, it flows to the cylinder through the valve plate (oil suction process). During the stroke from the top dead center to the bottom dead center, the plunger always moves in the direction of the reduced oil discharge, so the hydraulic oil is discharged through the oil discharge port (Draining process). The amount of oil discharged changes with the change of the inclination of the swash plate. The hydraulic oil sucked through the cylinder suction port is discharged through the oil discharge port of the distribution plate, while the hydraulic oil sucked through the oil suction port of the outer (inner) ring of the cylinder is discharged through the oil discharge port of the outer (inner) ring of the distribution plate.
