Reciprocating piston pump

Patent metadata

Field	Value
Publication number	US-12404847-B2
Application number	US-202318382875-A
Country	US
Kind code	B2
Filing date	Oct 23, 2023
Priority date	Sep 19, 2019
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A pump system includes a housing defining a first internal volume and a second internal volume, a first piston positioned to separate the first internal volume into a first chamber and a second chamber, a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber, a first inlet check valve configured to permit fluid flow into the first chamber, a second inlet check valve configured to permit fluid flow into the third chamber, a directional control valve (DCV) repositionable between (a) a first position where the DCV is configured to fluidly couple the second chamber to a high pressure fluid source and (b) a second position where the DCV is configured to fluidly couple the fourth chamber to the high pressure fluid source, and a relief valve configured to supply a fluid to the DCV through an orifice to move the DCV.

First claim

What is claimed is:

1. A pump system comprising:
a housing defining a first internal volume and a second internal volume;
a first piston positioned to separate the first internal volume into a first chamber and a second chamber;
a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber;
a first inlet check valve configured to be at least fluidly coupled to a gas spring, the first inlet check valve positioned to permit a first fluid received from the gas spring to enter the first chamber;
a second inlet check valve configured to be at least fluidly coupled to the gas spring, the first inlet check valve positioned to permit the first fluid received from the gas spring to enter the third chamber;
a directional control valve (DCV) repositionable between (a) a first position where the DCV is configured to fluidly couple the second chamber to a second fluid from a high pressure fluid source and (b) a second position where the DCV is configured to fluidly couple the fourth chamber to the second fluid from the high pressure fluid source; and
a relief valve configured to supply the second fluid to the DCV through an orifice to move the DCV from the first position to the second position, wherein the orifice is separate from the relief valve and positioned to resist flow of the second fluid to the relief valve.

2. The pump system of claim 1 , wherein the second fluid is supplied by the high pressure fluid source.

3. The pump system of claim 1 , wherein the relief valve is fluidly coupled to the second chamber through the orifice.

4. The pump system of claim 1 , further comprising a piston rod extending between the first piston and the second piston such that a movement of the first piston causes an equal movement of the second piston.

5. The pump system of claim 4 , wherein the housing includes a divider separating the second chamber from the fourth chamber, and wherein the divider defines a piston rod aperture through which the piston rod extends.

6. The pump system of claim 1 , wherein the first inlet check valve is directly fluidly coupled to the first chamber throughout an entire range of motion of the first piston, and wherein the second inlet check valve is directly fluidly coupled to the third chamber throughout the entire range of motion of the second piston.

7. The pump system of claim 1 , wherein the housing defines a first outlet passage fluidly coupled to the first chamber and a second outlet passage fluidly coupled to the third chamber, and wherein the first outlet passage is fluidly coupled to the second outlet passage.

8. The pump system of claim 1 , wherein the first chamber contains a gas, and wherein the second chamber contains a liquid.

9. The pump system of claim 1 , wherein the first piston and the second piston are configured to translate along an actuation axis, and wherein the first piston and the second piston are centered about the actuation axis.

10. The pump system of claim 1 , wherein the second chamber and the fourth chamber are positioned between the first chamber and the third chamber.

11. A pump system comprising:
a housing defining a first internal volume and a second internal volume;
a first piston positioned to separate the first internal volume into a first chamber and a second chamber;
a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber, wherein the first chamber and the third chamber are configured to receive a first fluid from a gas spring at a low pressure, and the second chamber and the fourth chamber are configured to receive a second fluid from a second fluid source;
a directional control valve (DCV) repositionable between (a) a first position where the DCV is configured to fluidly couple the second chamber to a reservoir and (b) a second position where the DCV is configured to fluidly couple the fourth chamber to the reservoir; and
a relief valve configured to supply the second fluid through an orifice to move the DCV between the first position and the second position in response to a pressure at a point between the relief valve and the orifice reaching a preset shift pressure.

12. The pump system of claim 11 , wherein the DCV is configured to fluidly couple a fluid source to the fourth chamber in the first position, wherein the DCV is configured to fluidly couple the fluid source to the second chamber in the second position, and wherein the fluid is supplied by the fluid source, and wherein when the second fluid is supplied to the second chamber or the fourth chamber, the first fluid is forced out of one of the first chamber or the third chamber at a high pressure by one of the first piston or the second piston and into the gas spring.

13. The pump system of claim 11 , wherein the relief valve is fluidly coupled to the second chamber through the orifice.

14. The pump system of claim 11 , wherein the relief valve is a first relief valve, further comprising a second relief valve fluidly configured to supply the second fluid to the DCV to move the DCV between the second position and the first position.

15. A pump system comprising:
a housing defining a first internal volume and a second internal volume;
a first piston positioned to separate the first internal volume into a first chamber and a second chamber;
a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber, wherein the first chamber and the third chamber are configured to receive a first fluid from a gas spring at a low pressure, and the second chamber and the fourth chamber are configured to receive a second fluid from a second fluid source;
a directional control valve (DCV) fluidly coupled to the second chamber and the fourth chamber;
a relief valve fluidly coupled to the DCV via a control line and the second chamber via a sensing line; and
an orifice positioned along the sensing line,
wherein the relief valve is configured to reposition the DCV in response to a pressure at a point between the relief valve and the orifice reaching a shift pressure, and wherein the orifice is positioned to cause a delay in a flow of a fluid along the sensing line, such that a pressure within the second chamber exceeds the shift pressure when the pressure at the point between the relief valve and the orifice reaches the shift pressure.

16. The pump system of claim 15 , wherein the DCV is repositionable between (a) a first position where the DCV fluidly couples the second chamber to a reservoir and (b) a second position where the DCV fluidly couples the fourth chamber to the reservoir.

17. The pump system of claim 15 , wherein the DCV is repositionable between (a) a first position where the DCV fluidly couples the fourth chamber to the second fluid source and (b) a second position where the DCV fluidly couples the second chamber to the second fluid source.

18. The pump system of claim 1 , wherein the relief valve is configured to supply the second fluid to the DCV through the orifice to move the DCV from the first position to the second position in response to a pressure at a point between the relief valve and the orifice exceeding a preset shift pressure.

19. The pump system of claim 1 , wherein the relief valve is configured to supply the second fluid to the DCV through the orifice to move the DCV from the first position to the second position in response to a pressure at a point between the relief valve and the orifice reaching a shift pressure, wherein the high pressure fluid source is configured

Assignees

• Oshkosh Corp

Inventors

• Schubart Kai P
• Rukas Christopher J
• Dillman Patrick S
• Ellifson Erik S
• Rositch Aaron J

Classifications

• F04B27/005

  with two cylinders · CPC title

• F15B15/1447

  Pistons; Piston to piston rod assemblies · CPC title

• F04B49/22

  by means of valves (F04B49/03 takes precedence) · CPC title

• F04B27/053

  with an actuating element at the inner ends of the cylinders · CPC title

• F04B35/008

  the means being a fluid transmission link · CPC title