Hydraulic pump

Patent metadata

Field	Value
Publication number	US-2023332594-A1
Application number	US-202118028853-A
Country	US
Kind code	A1
Filing date	Sep 28, 2021
Priority date	Sep 28, 2020
Publication date	Oct 19, 2023
Grant date	—

Abstract

A hydraulic pump includes: a valve plate including a suction port and a delivery port; a valve cover to which the valve plate is mounted; and a cylinder block that slides on the valve plate. The valve cover includes a suction passage and a delivery passage. The valve cover includes: a first chamber that communicates with the delivery passage through a communication passage and functions as a Helmholtz resonator; and a second chamber that communicates with the delivery passage, or with the first chamber, through an introduction passage including a restrictor. In the valve cover and the valve plate, a supply passage extends from the second chamber to a bottom dead center-side sealing surface of the valve plate, the bottom dead center-side sealing surface being a surface located between the suction port and the delivery port. The supply passage includes a restrictor.

First claim

1 . A hydraulic pump comprising:
a valve plate including a suction port and a delivery port; a valve cover to which the valve plate is mounted, the valve cover including a suction passage that communicates with the suction port and a delivery passage that communicates with the delivery port; and a cylinder block that slides on the valve plate, the cylinder block including cylinder bores that receive therein respective pistons, wherein the valve cover includes:
a first chamber that communicates with the delivery passage through a communication passage and functions as a Helmholtz resonator; and
a second chamber that communicates with the delivery passage, or with the first chamber, through an introduction passage, and
in the valve cover and the valve plate, a supply passage extends from the second chamber to a bottom dead center-side sealing surface of the valve plate, the bottom dead center-side sealing surface being a surface located between the suction port and the delivery port.

2 . The hydraulic pump according to claim 1 , wherein
at least a part of the introduction passage functions as a restrictor.

3 . The hydraulic pump according to claim 1 , wherein
at least a part of the supply passage functions as a restrictor.

4 . The hydraulic pump according to claim 1 , wherein
the first chamber and the second chamber are located between the suction passage and the delivery passage.

5 . The hydraulic pump according to claim 4 , wherein
the valve cover includes a recess in which a bearing is fitted, the bearing rotatably supporting a rotational shaft that penetrates the cylinder block, and at least a part of the first chamber and at least a part of the second chamber are positioned within a region that is surrounded by the recess, the suction passage, and the delivery passage.

6 . The hydraulic pump according to claim 1 , wherein
the first chamber and the second chamber are located side by side in an axial direction of a rotational shaft that penetrates the cylinder block.

7 . The hydraulic pump according to claim 6 , wherein
the second chamber is positioned between the valve plate and the first chamber.

8 . The hydraulic pump according to claim 1 , further comprising a rotational shaft that penetrates the cylinder block, wherein
when seen in an axial direction of the rotational shaft, the second chamber extends in a manner to straddle the bottom dead center-side sealing surface and a top dead center-side sealing surface of the valve plate, the top dead center-side sealing surface being a surface located between the suction port and the delivery port.

9 . The hydraulic pump according to claim 1 , wherein
a volume of the second chamber is less than a volume of the first chamber.

Assignees

• Kawasaki Heavy Ind Ltd

Inventors

• Yoshida Takeshi
• Miura Hidetoshi
• Hirano Yasunori
• Makino Yuta
• Hyodo Yuya

Classifications

• F04B39/0066

  using sidebranch resonators, e.g. Helmholtz resonators · CPC title

• F04B11/0091

  using a special shape of fluid pass, e.g. throttles, ducts · CPC title

• F04B11/0016

  with a fluid spring · CPC title

• F04B11/0008

  using accumulators · CPC title

• F04B53/004 Primary

  by mechanical resonators · CPC title