	US 11,994,098 B2
	Valve plate, cylinder block, and hydraulic motor
Mitsutaka Ikeda, Tokyo (JP)
Assigned to Komatsu Ltd., Tokyo (JP)
Appl. No. 18/018,053
Filed by Komatsu Ltd., Tokyo (JP)
PCT Filed Sep. 7, 2021, PCT No. PCT/JP2021/032894 § 371(c)(1), (2) Date Jan. 26, 2023, PCT Pub. No. WO2022/054808, PCT Pub. Date Mar. 17, 2022.
Claims priority of application No. 2020-154113 (JP), filed on Sep. 14, 2020.
Prior Publication US 2023/0279833 A1, Sep. 7, 2023
Int. Cl. F03C 1/06 (2006.01); F01B 3/00 (2006.01); F03C 1/34 (2006.01); F04B 1/2021 (2020.01)

CPC F03C 1/0655 (2013.01) [F01B 3/0047 (2013.01); F01B 3/0055 (2013.01); F03C 1/0647 (2013.01); F04B 1/2021 (2013.01)]

18 Claims

1. 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.

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

a plurality of pad oil grooves communicating with the first oil groove and opening toward the valve plate is provided in a pad region contacting the valve plate between the second oil grooves, and

the plurality of pad oil grooves is provided such that a proportion of an opening area with respect to the valve plate 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.