HYDRAULIC ROTATING MACHINE

PROBLEM TO BE SOLVED: To reduce manhours of hole work at working time of a valve plate, enhance workability, and reduce a cost. SOLUTION: The valve plate 21 slidingly contacting with an end surface of a cylinder block 6 is arranged in a head casing 3 of a hydraulic motor, and this valve plate 21 is fixed to the head casing 3 by using hollow pins 27 and 28. A drain passage 24 is arranged in the head easing 3, and a third passage part 24C of this drain passage 24 and the shaft directional one side of the hollow pin 27 are communicated with each other. The shaft directional other side of the hollow pin 27 is opened between sliding contact surfaces of the cylinder block 6 and the valve plate 21. Thus, an oil liquid leaking in an annular space S from the inside of a cylinder 7 when actuating the hydraulic motor is introduced to the drain passage 24 through the hollow pin 27 from between the sliding contact surfaces of the cylinder block 6 and the valve plate 21 to be discharged outside.