Piston assembly

Patent metadata

Field	Value
Publication number	US-10082207-B2
Application number	US-201514960816-A
Country	US
Kind code	B2
Filing date	Dec 7, 2015
Priority date	Dec 23, 2014
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A piston assembly may include a piston rod and a piston disposed on the piston rod. The piston may include a frame end cap defining a through-bore for receiving the piston rod, and the frame end cap may form a first end of the piston. The piston may include an outer end cap defining a through-bore for receiving the piston rod, and the outer end cap may form a second end of the piston. The piston may also include a center support defining a through-bore for receiving the piston rod. The center support may be disposed between the frame end cap and the outer end cap, and an outer surface of the piston rod and an inner circumferential surface of the center support may define a radial gap.

First claim

We claim:

1. A piston assembly, comprising:
a piston rod comprising: a shoulder having a diameter, first land and a second land disposed between first and second axial ends of the piston rod on one side of the shoulder, wherein diameters of the piston rod at the first and second lands are equal and smaller than the diameter of the shoulder, and diameter of the piston rod is smaller between the first and second lands; and
a piston positioned on the piston rod between the shoulder and the second axial end of the piston rod, the piston comprising:
a first end cap having first and second axial ends, the first end cap defining a circumferential recess between the first and second axial ends of the the first end cap, and a second end cap having first and second axial ends, the first end cap and the second end cap forming a first end and a second end of the piston, respectively, wherein the first end cap is supported by the first land, and the second end cap is supported by the second land, and
a center support disposed between the first end cap and the second end cap, the center support having an outer circumferential surface contiguous with respective outer circumferential surfaces of the first end cap and the second end cap, a first axial end of the center support abutting the second axial end of the first end cap, and a second axial end of the center support abutting the first axial end of the second end cap, and a sleeve concentrically oriented within and spaced radially inwardly from the outer circumferential surface of the center support, the sleeve defining a through-bore extending between the first and second axial ends of the center support for receiving the piston rod, the sleeve positioned within the circumferential recess of the first end cap, wherein an inner circumferential surface of the through-bore and an outer surface of the piston rod define a radial gap therebetween; and
a collar positioned between the shoulder of the piston rod and the first end cap of the piston, the collar configured to expand into a circumferential indention of the piston rod and a circumferential inset of the piston.

2. The piston assembly of claim 1 , wherein the radial gap extending an axial length of the center support.

3. A piston assembly, comprising:
a piston rod comprising a first land and a second land disposed between first and second axial ends of the piston rod, the first land and the second land axially separated from one another by a necked portion of the piston rod having a diameter smaller than diameters of the first and second lands; and
a piston circumscribing the piston rod over the first and second lands and the necked portion thereof, comprising:
a frame end cap having an outer circumferential surface, first and second axial ends, and defining a first through-bore between the first and second axial ends of the frame cap, for receiving the piston rod, the first through-bore defining an inner cylindrical surface with a circumferential recess having a recess diameter greater than diameter of the first through-bore, the recess formed in the second axial end of the frame cap, the outer circumferential surface and the first axial end of the frame end cap forming a first end of the piston and supported by the first land of the piston rod contacting the inner cylindrical surface of the first through-bore,
an outer end cap having an outer circumferential surface, first and second axial ends, and defining a second through-bore for receiving the piston rod, the outer circumferential surface and the second axial end of the outer end cap forming a second end of the piston, and supported by the second land of the piston rod contacting an inner cylindrical surface of the second through-bore, and
a center support oriented axially between the frame end cap and the outer end cap, having an outer circumferential surface contiguous with respective outer circumferential surfaces of the frame end cap and the outer end cap, a first axial end abutting the second axial end of the frame end cap, and a second axial end abutting the first axial end of the outer end cap, and a sleeve concentrically oriented within and spaced radially inwardly from the outer circumferential surface of the center support, the sleeve defining a third through-bore for receiving the piston rod, the sleeve oriented within the circumferential recess of the frame end cap, wherein an inner circumferential surface of the third through-bore and an outer surface of the piston rod define a radial gap therebetween.

4. The piston assembly of claim 3 , wherein the sleeve is integral with the center support.

5. The piston assembly of claim 3 , wherein the sleeve and the radial gap extend between the first and second ends of the center support over the necked portion of the piston rod.

6. The piston assembly of claim 3 , wherein:
the piston rod includes a shoulder positioned between the first and second axial ends of the piston rod, and
the piston is disposed on the piston rod between the shoulder and the second end of the piston rod.

7. The piston assembly of claim 6 , wherein:
the frame end cap is disposed proximate the shoulder of the piston rod, and
the outer end cap is disposed adjacent the second end of the piston rod.

8. The piston assembly of claim 7 , wherein a collar is positioned between the frame end cap and the shoulder of the
piston rod.

Assignees

• Eaton Jr Elmer B
• Cliff Malcolm J
• Sandham John K
• Burdick Jr Waldo E
• Dresser Rand Co

Inventors

• Eaton Jr Elmer B
• Cliff Malcolm J
• Sandham John K
• Burdick Jr Waldo E

Classifications

• F16J7/00

  Piston-rods · CPC title

• F16J1/12 Primary

  with piston-rods, e.g. rigid connections · CPC title

• F16J1/008

  with sealing lips · CPC title

• F16J1/005

  obtained by assembling several pieces · CPC title

• F04B53/14

  Pistons, piston-rods or piston-rod connections · CPC title