US 11,815,078 B2
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
Kai P. Schubart, Oshkosh, WI (US); Christopher J. Rukas, Oshkosh, WI (US); Patrick S. Dillman, Hartford, WI (US); Erik S. Ellifson, Oshkosh, WI (US); and Aaron J. Rositch, Oshkosh, WI (US)
Assigned to Oshkosh Corporation, Oshkosh, WI (US)
Filed by Oshkosh Corporation, Oshkosh, WI (US)
Filed on Oct. 6, 2022, as Appl. No. 17/961,182.
Application 17/961,182 is a continuation of application No. 16/575,590, filed on Sep. 19, 2019, granted, now 11,480,165.
Prior Publication US 2023/0046193 A1, Feb. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. F04B 27/067 (2006.01); F04B 27/00 (2006.01); F15B 15/14 (2006.01)
CPC F04B 27/0673 (2013.01) [F15B 15/1447 (2013.01); F04B 27/005 (2013.01)] 19 Claims
OG exemplary drawing
 
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, the second piston coupled to the first piston;
a first inlet check valve configured to be at least selectively fluidly coupled to a reservoir, the first inlet check valve positioned to permit a first fluid received from the reservoir to enter the first chamber;
a second inlet check valve configured to be at least selectively fluidly coupled to the reservoir, the second inlet check valve positioned to permit the first fluid received from the reservoir to enter the third chamber;
a directional control valve (DCV) fluidly coupled to the second chamber and the fourth chamber, the DCV configured to alternately supply a second fluid to the second chamber and the fourth chamber such that the first fluid is forced out of one of the first chamber or the third chamber, the 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 fluidly coupled to the second chamber through a sensing line, the relief valve configured to supply the second fluid to the DCV through an orifice in response to a pressure within the sensing line exceeding a shift pressure to move the DCV from the first position to the second position.