Hydraulic Pump displacement depends on the bore and stroke of a piston and the number of pistons. A swash plate’s angle determines the stroke, which can vary the hydraulic pump displacement by changing the angle. In a fixed angle’s unit, a swash plate is stationary in the housing. In a variable unit’s, it is mounted on a yoke, which can turn on pintles. Different controls can be attached to the pintles to vary hydraulic pump displacement delivery from zero to the maximum. With certain controls, the direction of flow can be reversed by swinging a yoke past center. In the center position, a swash plate is perpendicular to the cylinder’s, and there is no piston reciprocation; no oil is pumped. Read More