Variable displacement axial piston device

A variable displacement axial piston device comprising:

• a cylinder block that rotates around a rotational axis line;
• a plurality of pistons that are accommodated in the cylinder block in a relatively non-rotatable manner around the rotational axis line with respect thereto and in a reciprocating manner along the rotational axis line with respect thereto;
• a trunnion type movable swash plate capable of varying a reciprocating range in which the plurality of pistons can move;
• and
• a housing that accommodates the cylinder block, wherein the movable swash plate includes a swash plate main body that has an engagement surface with which free ends of the plurality of pistons are engaged, and a trunnion shaft that extends outward in a radial direction of the rotational axis line and is supported in a rotatable manner by a bearing portion provided in the housing so as to be located coaxially with a slanting axis line,
• wherein an outer circumferential surface of the trunnion shaft includes a sliding contact region that has a circular arc shape as viewed along the slanting axis line and is brought into contact with an inner circumferential surface of the bearing portion in a rotatably sliding manner, and at least one suction groove in the inner circumferential surface of the bearing portion that forms a pocket portion between the suction groove and the inner circumferential surface of the bearing portion, and
• wherein the pocket portion is opened to an inner space of the housing on at least one side in an axis line direction of the trunnion shaft.