Valve plate, cylinder block, and hydraulic motor

A valve plate of a hydraulic motor, the valve plate comprising a first pressure port and a second pressure port on a circumference about a rotation axis, a first oil groove provided to be endless in an outer peripheral part with respect to the first pressure port and the second pressure port, and a plurality of second oil grooves extending from the first oil groove toward an outer periphery, the first pressure port and the second pressure port being alternately communicated with a cylinder bore provided in a cylinder block by bidirectional relative rotation about the rotation axis in a state of being in contact with an end face of the cylinder block, wherein

• a plurality of pad oil grooves communicating with the first oil groove and opened toward the end face of the cylinder block is provided in outer peripheral portions of the first pressure port and the second pressure port in a pad region contacting the end face of the cylinder block between the second oil grooves, and
• the plurality of pad oil grooves is provided such that a proportion of an opening area to the end face of the cylinder block is larger at two end portions close to the second oil grooves than at a central portion separated from the second oil grooves in a circumferential direction of relative rotation.