Method of disassembling a cold head and lifting-up jig

Patent metadata

Field	Value
Publication number	US-11278994-B2
Application number	US-202016794202-A
Country	US
Kind code	B2
Filing date	Feb 18, 2020
Priority date	Feb 19, 2019
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

Provided is a method of disassembling a cold head provided with a displacer that extends in an axial direction, a cylinder that accommodates the displacer, and a displacer drive unit that is fastened to the cylinder and is connected to the displacer such that the displacer is driven in the axial direction, the method including mounting a lifting-up jig onto the displacer drive unit, unfastening the displacer drive unit and the cylinder from each other, and operating the lifting-up jig such that the displacer drive unit is lifted up from the cylinder together with the displacer.

First claim

What is claimed is:

1. A method of disassembling a cold head provided with a displacer that extends in an axial direction, a cylinder that accommodates the displacer, and a displacer drive unit that is fastened to the cylinder and is connected to the displacer such that the displacer is driven in the axial direction, the method comprising:
mounting a lifting-up jig onto the displacer drive unit;
unfastening the displacer drive unit from the cylinder; and
operating the lifting-up jig such that the displacer drive unit is lifted up from the cylinder together with the displacer,
wherein the lifting-up jig is provided with a lifting-up jig main body that includes a lifting-up bolt hole and a lifting-up bolt that is screwed into the lifting-up bolt hole,
wherein the mounting of the lifting-up jig includes attaching the lifting-up jig main body to the displacer drive unit such that the lifting-up bolt is disposed to be parallel to the axial direction of the cold head, and
wherein the operating of the lifting-up jig includes rotating the lifting-up bolt relative to the lifting-up jig main body with the lifting-up bolt not moving in the axial direction.

2. The method according to claim 1 , further comprising:
detaching the displacer drive unit from the displacer together with the lifting-up jig.

3. The method according to claim 1 , further comprising:
mounting a displacer holding jig onto the displacer; and
detaching the displacer drive unit from the displacer together with the lifting-up jig,
wherein the displacer is held by the displacer holding jig in a state of being lifted up from the cylinder.

4. The method according to claim 1 , further comprising:
mounting a displacer extraction jig onto the displacer; and
raising the displacer extraction jig together with the displacer such that the displacer is extracted from the cylinder.

5. A method of disassembling a cold head provided with a displacer that extends in an axial direction, a cylinder that accommodates the displacer, and a displacer drive unit that is fastened to the cylinder and is connected to the displacer such that the displacer is driven in the axial direction, the method comprising:
mounting a lifting-up jig onto the displacer drive unit;
unfastening the displacer drive unit from the cylinder;
operating the lifting-up jig such that the displacer drive unit is lifted up from the cylinder together with the displacer; and
detaching the displacer drive unit from the displacer together with the lifting-up jig.

6. The method according to claim 5 , further comprising:
mounting a displacer holding jig onto the displacer,
wherein the displacer is held by the displacer holding jig in a state of being lifted up from the cylinder.

7. The method according to claim 5 , further comprising:
mounting a displacer extraction jig onto the displacer; and
raising the displacer extraction jig together with the displacer such that the displacer is extracted from the cylinder.

8. A method of disassembling a cold head provided with a displacer that extends in an axial direction, a cylinder that accommodates the displacer, and a displacer drive unit that is fastened to the cylinder and is connected to the displacer such that the displacer is driven in the axial direction, the method comprising:
mounting a lifting-up jig onto the displacer drive unit;
unfastening the displacer drive unit from the cylinder;
operating the lifting-up jig such that the displacer drive unit is lifted up from the cylinder together with the displacer;
mounting a displacer extraction jig onto the displacer; and
raising the displacer extraction jig together with the displacer such that the displacer is extracted from the cylinder.

Assignees

• Sumitomo Heavy Industries

Inventors

• Nishio Tatsuki
• Adachi Shuntaro

Classifications

• B25B27/02 Primary

  for connecting objects by press fit or detaching same {(B25D1/16 takes precedence)} · CPC title

• B23P15/26 Primary

  heat exchangers {or the like (making heat exchangers by methods covered by other subclasses B21D53/02)} · CPC title

• F25B2309/1414

  Pulse-tube cycles characterised by pulse tube details · CPC title

• F25B9/14

  characterised by the cycle used, e.g. Stirling cycle · CPC title

• B66C1/22

  Rigid members, e.g. L-shaped members, with parts engaging the under surface of the loads; Crane hooks · CPC title