Excavator Pump Parts Swash Plate Ball With Grooves Ap2d36 Excavator Parts Spherical pivot supporting the swash plate Driven by the servo piston, the swash plate (cam plate) tilts and swings. The support hemisphere acts as the swinging pivot for the swash plate. The flat side of the hemisphere fits against the pump housing/cradle, while its spherical surface bears against the swash plate, enabling smooth adjustment of the swash plate tilt angle. Changes in the tilt angle alter