Reciprocating piston pump comprising a housing defining a first chamber and a second chamber cooperating with a first piston and a second piston to define a third chamber and a fourth chamber

Patent metadata

Field	Value
Publication number	US-11480165-B2
Application number	US-201916575590-A
Country	US
Kind code	B2
Filing date	Sep 19, 2019
Priority date	Sep 19, 2019
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A pump system includes a pump assembly and a pump controller. The pump assembly includes a housing defining a first volume and a second volume separated by a divider, a first piston dividing the first volume into a first chamber and a second chamber, a second piston dividing the second volume into a third chamber and a fourth chamber, and a piston rod coupling the first piston and the second piston such that a movement of the first piston causes an equal movement of the second piston. The pump controller is configured to alternately supply a first fluid to the second chamber and the fourth chamber to cause the first piston and the second piston to reciprocate within the housing.

First claim

What is claimed is:

1. An axle assembly for a vehicle, comprising
a wheel-end assembly;
a reservoir configured to contain a gas;
a pump assembly comprising:
a housing;
a first piston cooperating with the housing to define a first chamber and a second chamber;
a second piston coupled to the first piston and cooperating with the housing to define a third chamber and a fourth chamber;
a first inlet check valve at least selectively fluidly coupled to the reservoir and the first chamber and configured to permit the gas from the reservoir to enter the first chamber; and
a second inlet check valve at least selectively fluidly coupled to the reservoir and the third chamber and configured to permit the gas from the reservoir to enter the third chamber;

a gas spring coupled to the wheel-end assembly and at least selectively fluidly coupled to the first chamber and the third chamber;
a directional control valve (DCV) fluidly coupled to the second chamber and the fourth chamber and configured to alternately supply a fluid to the second chamber and the fourth chamber such that the gas is forced out of the first chamber and the third chamber and into the gas spring, the DCV being selectively repositionable between (a) a first position in which the DCV fluidly couples a high pressure fluid source to the second chamber and (b) a second position in which the DCV fluidly couples the high pressure fluid source to the fourth chamber; and
a relief valve fluidly coupled to the second chamber through a sensing line and configured to supply the fluid to the first valve DCV through an orifice to move the DCV from the first position to the second position in response to a pressure within the sensing line exceeding a shift pressure.

2. The axle assembly of claim 1 , wherein the pump assembly further comprises a piston rod coupling the first piston and the second piston such that a movement of the first piston causes an equal movement of the second piston.

3. The axle assembly of claim 1 , wherein the first inlet check valve is directly fluidly coupled to the first chamber throughout the 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.

4. The axle assembly of claim 1 , wherein the pump assembly further comprises:
an outlet check valve fluidly coupled to the first chamber and configured to prevent the gas from passing from the gas spring into the first chamber.

5. The axle assembly of claim 1 , wherein the pump assembly further comprises:
a first outlet check valve fluidly coupled to the first chamber and configured to prevent the gas from passing from the gas spring into the first chamber; and
a second outlet check valve fluidly coupled to the third chamber and configured to prevent the gas from passing from the gas spring into the third chamber.

6. The axle assembly 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,
wherein the first outlet passage is fluidly coupled to the second outlet passage.

7. The axle assembly of claim 1 , wherein the fluid is a liquid.

8. The axle assembly 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.

9. The axle assembly of claim 1 , wherein the pump assembly further comprises a piston rod coupling the first piston and the second piston, wherein the housing includes a divider separating the second chamber from the fourth chamber, and wherein the divider defines a piston rod aperture that receives the piston rod.

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

Assignees

• Oshkosh Corp

Inventors

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

Classifications

• F04B35/008

  the means being a fluid transmission link · CPC title

• F04B27/02

  having cylinders arranged oppositely relative to main shaft · CPC title

• F04B27/0673 Primary

  by using a valve in a system with several pumping chambers, wherein the flow-path through the chambers can be changed, e.g. series-parallel · CPC title

• F15B15/1447

  Pistons; Piston to piston rod assemblies · CPC title

• F04B27/005

  with two cylinders · CPC title