Patent ID: 6951164

Claim:
A swash plate plunger type hydraulic unit comprising: a cylinder which is rotatably supported and has a plurality of plunger holes extending in an axial direction and arranged in a loop to surround a rotation axis thereof; a plurality of plungers slidably disposed in the respective plunger holes; a swash plate which has a swash plate face to be contacted to outer end portions of the plungers, and which may be tilted and rolled about a rolling axis perpendicular to the rotation axis as a center to change the tilting angle of the swash plate face; and a swash plate servo device for tilting and rolling the swash plate, the swash plate servo device comprising: a screw shaft having a male screw; a nut member which has a ball thread on an inner wall thereof and is mated with the male screw and connected to the swash plate; a servo drive device which drives the screw shaft to move the nut member over the screw shaft in an axial direction to tilt and roll the swash plate; and a stopper attached to an end portion of the screw shaft to limit a moving range of the nut member, the stopper including a cylindrical ring portion which has almost the same outer diameter as the outer diameter of the male screw portion and is situated adjacent to the end portion of the male screw portion at a limit position of the nut member, and a flange portion which has a larger diameter than the ring portion and which contacts a side face of the nut member at the limit position.