Fluid pressure rotating machine

A fluid pressure rotating machine in which a piston projecting from a cylinder of a rotary cylinder block reciprocates, following a tiltable swash plate housed in a casing, comprising:

• a bush in the form of a curved plate held in sliding contact with a back surface of the tiltable swash plate;
• a supply/discharge passage includes a swash plate port formed on the swash plate and open on the back surface of the swash plate, and a bush port penetrating through the bush, the supply/discharge passage being provided from the piston to the swash plate;
• an elastic ring interposed between the casing and the bush and surrounding an opening end of the bush port;
• and
• a supporting surface formed on the casing for supporting the bush,
• wherein a pressure receiving area of the bush surrounded by the elastic ring and facing the supply/discharge passage is so set that a load obtained by a working fluid pressure of the supply/discharge passage pressing the bush against the back surface of the swash plate is lower than a load obtained by the back surface of the swash plate pressing the bush against the supporting surface.