Fluted piston components for pumps

Patent metadata

Field	Value
Publication number	US-2017191478-A1
Application number	US-201615395139-A
Country	US
Kind code	A1
Filing date	Dec 30, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

A piston rod and piston head are the driven components within a pump. An upstream end of the piston rod is attached within an aperture of the piston head. At least one flute extends between the upstream end of the piston rod and the aperture, and the at least one flute is configured to provide a flowpath for a fluid, such as paint, to flow downstream of the piston head and piston rod. The flutes facilitate a smooth downstream flow of the fluid, thereby reducing hydraulic resistance and reducing wear caused by the fluid.

First claim

1 . A piston rod for pumping fluid, the piston rod comprising:
a piston rod body elongated along a longitudinal axis, the piston rod body comprising one or more flutes, each of the one or more flutes respectively comprising an open groove that extends along an exterior of the piston rod body, wherein fluid flows within the one or more flutes during pumping.

2 . The piston rod of claim 1 , wherein the one or more flutes comprises at least two flutes arrayed around the piston rod body.

3 . The piston rod of claim 1 , wherein the one or more flutes comprises at least three flutes which are evenly arrayed around the piston rod body.

4 . The piston rod of claim 1 , wherein the piston rod body comprises:
a downstream end; an upstream end disposed opposite the downstream end; and at least two ridges located along the upstream end; wherein the one or more flutes comprises at least two flutes located along the upstream end, and the at least two flutes are defined by a corresponding number of the at least two ridges.

5 . The piston rod of claim 4 , wherein threading is formed on the at least two ridges.

6 . The piston rod of claim 1 , wherein the piston rod body further comprises an upstream face, and the one or more flutes are open on the upstream face.

7 . The piston rod of claim 1 , wherein each flute of the one or more flutes has a depth in the range of 20-40 percent of the diameter of the piston rod body.

8 . A piston for pumping fluid, the piston comprising:
the piston rod of claim 1 , the piston rod having a downstream end and an upstream end; and a piston head having a downstream aperture, the upstream end of the piston rod extending into the downstream aperture of the piston head.

9 . The piston of claim 8 , wherein the upstream end of the piston rod is attached to the piston head by interfaced threading on the piston rod and the piston head.

10 . The piston of claim 8 , wherein the piston head comprises a central bore in fluid communication with the one or more flutes, wherein the fluid flows through the central bore and then within the one or more flutes during pumping.

11 . The piston of claim 8 , and further comprising a check valve comprising a ball disposed within the piston head, wherein the piston rod serves as a downstream stop for the ball of the check valve.

12 . The piston of claim 8 , wherein the piston head is larger in diameter than the piston rod.

13 . The piston of claim 8 , wherein each of the one or more flutes extends into the downstream aperture and further extends downstream beyond the piston head such that each flute is partially covered by the piston head and partially exposed.

14 . A pump, the pump comprising:
the piston of claim 8 ; and a cylinder within which the piston is at least partially disposed, wherein the piston reciprocates within the cylinder to pump the fluid.

15 . The pump of claim 14 , and wherein:
the cylinder comprises a cylinder chamber; the piston head divides the cylinder chamber into an upstream chamber and a downstream chamber; the fluid being pumped flows from the upstream chamber to the downstream chamber by traveling from the upstream chamber into and through the piston head, flowing within the one or more flutes, and being expelled from the one or more flutes into the downstream chamber; and the one or more flutes provide the only flowpath between the upstream chamber and the downstream chamber such that the fluid being pumped must flow through the one or more flutes when flowing to the downstream chamber from the upstream chamber.

16 . A piston for pumping fluid by reciprocating along a longitudinal axis, the piston comprising:
a piston rod elongated to have a downstream end and an upstream end; a piston head having a head upstream face, an upstream bore open on the head upstream face, and a downstream aperture in fluid communication with the upstream bore, wherein the upstream end of the piston rod extends into the downstream aperture of the piston head, the piston head is larger in diameter than the piston rod, and the piston rod and the piston head are coaxial with the longitudinal axis; and at least two flutes in fluid communication with the upstream bore and along which the fluid being pumped flows, the at least two flutes formed one of along the downstream aperture of the piston head and along the upstream end of the piston rod.

17 . The piston of claim 16 , wherein the at least two flutes are evenly arrayed about the longitudinal axis.

18 . The piston of claim 17 , wherein:
the piston comprises a check valve; the piston rod comprises a rod upstream face; the at least two flutes are formed as grooves along the upstream end of the piston rod and are open on the upstream face of the piston rod; and each of the at least two flutes extends into the downstream aperture and further extends downstream beyond the piston head such that each flute is partially overlapped by the piston head and partially exposed.

19 . A pump for pumping fluid, the pump comprising:
a piston comprising:
a piston rod elongated to have a downstream end and an upstream end, the piston rod comprising two or more flutes extending along, and arrayed around, an exterior of the downstream end of the piston rod, each of the flutes comprising a groove formed into the exterior of the downstream end; and
a piston head having an downstream aperture, wherein the upstream end of the piston rod extends into the downstream aperture of the piston head; and
a cylinder within which the piston is at least partially disposed, wherein the piston is configured to reciprocate within the cylinder to pump fluid, and wherein all fluid being pumped must flow within at least one of the two or more flutes.

Assignees

• Graco Minnesota Inc

Inventors

• Horning Jeromy D
• Lins Christopher A

Classifications

• F04B7/06

  the pistons and cylinders being relatively reciprocated and rotated · CPC title

• F04B53/148

  the piston being provided with channels which are coacting with the cylinder and are used as a distribution member for another piston-cylinder unit · CPC title

• F04B17/03

  driven by electric motors · CPC title

• F04B19/003

  free-piston type pumps · CPC title

• F04B53/126

  Ball valves · CPC title