Motion of the Piston in Piston Pumps and Motors. (Experiments and Theoretical Discussion).

Under low-speed operation the frictional characteristics of a piston with hydrostatic pads and a conventional piston were experimentally obtained and compared with the theoretical results previously reported. The metallic contacting force under medium- and high-speed operations is given theoretically. Finally, the effect of conically arranged cylinder bores on reduction of the radial loads acting on pistons is discussed.