Cryocooler Disassembly Method for Scotch Yoke Guide Replacement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The guide in a cryocooler, typically made of synthetic resin, undergoes significant abrasion when used with a metal scotch yoke, making it difficult to perform its guiding and rotational restriction functions effectively over time.

Innovation Solution

A method for disassembling the cryocooler involves removing the lower cover from the housing to extract the scotch yoke guide, allowing for its replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the scotch yoke guide is made of synthetic resin material, then the cost and weight are reduced, but the guide undergoes significant abrasion when sliding with metal scotch yoke, reducing reliability

Engineering Contradiction:
Improveguide durabilityVSAvoidabrasion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The guide is divided into a guide body and separate guide pins. The guide pins are made of wear-resistant material and can be replaced independently when worn, while the guide body remains intact. This segmentation allows selective replacement of only the worn components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guide pins are made of material with different properties (higher wear resistance) than the guide body. This material parameter change in critical wear areas solves the abrasion problem while maintaining the overall benefits of using synthetic resin.

Inventive Principle:
Principle #35Parameter changes

2Ease of repair

If the guide is designed to be removable for replacement, then maintenance becomes easier, but the device complexity increases

Engineering Contradiction:
Improveguide replacementVSAvoiddisassembly structure
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The guide is segmented into a guide body and removable guide pins. The guide pins are designed to be extractable through the lower opening without removing the entire guide assembly, enabling simple maintenance while keeping the overall structure relatively simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guide pins are extracted as separate replaceable components from the guide body. This extraction design allows the pins to be removed and replaced independently through the lower opening, simplifying maintenance procedures.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4446671B1Method for disassembling cryogenic freezer
Publication Date: 2026.02.18 SUMITOMO HEAVY IND LTD
  • EP4446671B1 patent drawingFigure 1
  • EP4446671B1 patent drawingFigure 2
  • EP4446671B1 patent drawingFigure 3

AI summary

There is provided a method for disassembling a cryocooler including a housing (20) having a lower opening (21), a lower cover that closes the lower opening (21), a scotch yoke shaft (45) that is accommodated in the housing (20) and extends out of the housing (20) by penetrating the lower cover, and a scotch yoke guide (54) that is removably provided in the housing (20) and guides axial movement of the scotch yoke shaft (45), the method including removing the lower cover from the housing (20), and taking the scotch yoke guide (54) out of the housing (20) from the lower opening (21).