Reciprocating pushrod assembly and cryogenic pump

Patent metadata

Field	Value
Publication number	US-10495083-B2
Application number	US-201715609493-A
Country	US
Kind code	B2
Filing date	May 31, 2017
Priority date	May 31, 2017
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

A pushrod assembly 5 may include a seal carrier 50 for a spaced seal assembly 60 and/or a seal carrier 70 for a stacked seal assembly 74 , the spaced seal assembly including first and second annular seals 61, 62 separated by a spacer 63 to isolate between the seals a vented region 28 of the pushrod housing 6 , the stacked seal assembly including at least two annular seals 80 stacked on the seal carrier. Each seal assembly can be removed and replaced via an access end 52, 72 of the seal carrier after detaching the access end from an adjacent component of the assembly. The seal carriers may be incorporated into a cryogenic pump 2 wherein at least one annular seal is arranged on each seal carrier to seal the pushrod assembly 5 within its housing 6.

First claim

What is claimed is:

1. A pushrod assembly for use in a pump having a housing with a vented region, the pushrod assembly including:
a plurality of pushrod components operatively connected together in series along an axis of the assembly to transmit reciprocal motion between a driving end and a driven end of the assembly, said pushrod components including a spaced seal assembly carrier; and
a spaced seal assembly, the spaced seal assembly including at least a first annular seal, a second annular seal, and an annular spacer;
the spaced seal assembly carrier extending axially through the spaced seal assembly with the spacer axially interposed between the first annular seal and the second annular seal, each of the first annular seal and the second annular seal being received on a respective seat region of the spaced seal assembly carrier and retained between axially opposed abutment surfaces of the pushrod assembly;
the pushrod assembly being receivable in the housing of the pump in a use position wherein the first and second seals slidingly engage the housing and sealingly isolate the vented region of the housing between the first annular seal and the second annular seal;
wherein the spaced seal assembly carrier has an access end and is detachably connectable at the access end to an adjacent one of the pushrod components so that when detached the access end can be slidingly axially inserted into the spaced seal assembly.

2. A pushrod assembly according to claim 1 , wherein a transverse section area of the spaced seal assembly carrier at each seat region is not less than a maximum transverse section area of the spaced seal assembly carrier between each seat region and the access end.

3. A pushrod assembly according to claim 1 , wherein the spacer and the spaced seal assembly carrier have substantially equal coefficients of thermal expansion.

4. A pushrod assembly according to claim 1 , wherein the spaced seal assembly carrier is arranged proximate the driving end of the assembly;
and the first annular seal and the second annular seal are configured to be biased radially outwardly by fluid pressure from the driving end of the assembly;
and the spaced seal assembly includes a third annular seal, the first annular seal and the second annular seal and the spacer being axially interposed between the third annular seal and the driving end of the assembly, and the third annular seal is configured to be biased radially outwardly by fluid pressure from the driven end of the assembly.

5. A pushrod assembly for use in a pump having a housing, the pushrod assembly including:
one or more pushrod components configured to transmit reciprocal motion along an axis of the assembly between a driving end and a driven end of the assembly, said one or more pushrod components including a stacked seal assembly carrier; and
a stacked seal assembly, the stacked seal assembly including at least two annular seals;
the stacked seal assembly carrier extending axially through the stacked seal assembly, the at least two annular seals being arranged in series on a seat region of the stacked seal assembly carrier and retained between axially opposed abutment surfaces of the pushrod assembly;
the pushrod assembly being receivable in the housing of the pump in a use position wherein the at least two annular seals slidingly engage the housing;
wherein each of the at least two annular seals is configured to be biased radially outwardly by fluid pressure from the driven end of the assembly,
and the stacked seal assembly carrier has an access end and is detachably connectable at the access end to an adjacent one of the one or more pushrod components so that when detached the access end can be slidingly axially inserted into the stacked seal assembly.

6. A pushrod assembly according to claim 5 , wherein a transverse section area of the stacked seal assembly carrier at the seat region is not less than a maximum transverse section area of the stacked seal assembly carrier between the seat region and the access end.

7. A pushrod assembly according to claim 5 , wherein the stacked seal assembly is arranged to operate at a cryogenic temperature proximate the driven end of the assembly.

Assignees

• Caterpillar Inc

Inventors

• Stockner Alan
• Brown Aaron M
• Thangaswamy Sridhar
• Coldren Dana R
• Gibson Dennis

Classifications

• F04B53/143

  Sealing provided on the piston · CPC title

• F04B15/06

  for liquids near their boiling point, e.g. under subnormal pressure · CPC title

• F04B53/14

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

• F04B53/144 Primary

  Adaptation of piston-rods · CPC title