Scroll Chuck Jaw and Plate Layout for Thermal-Stable Gripping

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Solution Overview

Problem

The gripping force of scroll gear-type chucks decreases due to temperature changes caused by differences in thermal expansion coefficients between the chuck and the gripped body, potentially leading to the gripped body falling and damage.

Innovation Solution

A scroll chuck design with jaws and chuck plates made from materials with specific thermal expansion coefficients, where the thermal expansion coefficient of the jaws is between 0.5 to 19.0×10^-6/K and the chuck plates' coefficient is between 16.0 to 24.0×10^-6/K, ensuring the gripping force remains consistent across temperature changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a scroll gear-type chuck is used for gripping, then the gripping mechanism can effectively hold the gripped body, but the gripping force decreases due to temperature changes caused by thermal expansion coefficient differences

Engineering Contradiction:
Improvegripping force consistencyVSAvoidtemperature change effect
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different thermal expansion coefficient characteristics to different parts of the gripping mechanism. Specifically, the chuck body is designed with a first thermal expansion coefficient while the gripping element (jaws or collet) is designed with a second thermal expansion coefficient that is different from the first. This local differentiation of material properties allows the gripping mechanism to compensate for thermal expansion effects, maintaining consistent gripping force across temperature changes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the thermal expansion parameter (coefficient) of different components to resolve the temperature-related gripping force degradation. By selecting materials with specific thermal expansion coefficients for the chuck body and gripping element, the system compensates for thermal effects. The mathematical relationships in the patent show how the gripping force remains constant when the thermal expansion coefficients of different parts are properly matched, transforming the temperature sensitivity issue into a material selection parameter optimization problem.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If materials with different thermal expansion coefficients are used for chuck components, then temperature resistance improves, but material selection and manufacturing complexity increases

Engineering Contradiction:
Improvetemperature resistanceVSAvoidmaterial selection complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent specifies that the chuck body and gripping element should have different thermal expansion coefficients, applying the local quality principle by assigning different material properties to different components. This targeted approach to material selection focuses the complexity only where needed (at the interface between chuck body and gripping element) rather than requiring complex materials throughout the entire mechanism.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transforms the material selection problem into a parameter optimization problem by providing mathematical relationships that guide the selection of thermal expansion coefficients. The patent includes specific formulas that relate the thermal expansion coefficients of different components to the gripping force, allowing manufacturers to select materials based on quantitative criteria rather than trial and error, thereby reducing overall manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design maintains a consistent gripping force despite temperature changes, preventing the gripped body from falling and ensuring stability during manufacturing processes like optical fiber base material production.

Implementation Method 1

temperature changes caused by differences in thermal expansion coefficients between the chuck and the gripped body

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3147054B1Arrangement comprising a gripping mechanism and a gripped body
Publication Date: 2022.07.06 SHIN ETSU CHEMICAL CO LTD
  • EP3147054B1 patent drawingFigure 1
  • EP3147054B1 patent drawingFigure 2
  • EP3147054B1 patent drawingFigure 3

AI summary

A gripping mechanism includes: a plurality of chuck jaws (130) that, when having come close to each other, generate a gripping force on a gripped body (150); a chuck body (110) that holds the plurality of chuck jaws on a common planar surface, and moves them on the planar surface; and a plurality of chuck plates (140) that, when each of the plurality of chuck jaws (130) grips the gripped body (150), are interposed between each of the plurality of chuck jaws (130) and the gripped body (150), wherein a thermal expansion coefficient α1 of the plurality of chuck jaws (130), a thermal expansion coefficient α2 of the plurality of chuck plates (140) and a thermal expansion coefficient αw of the gripped body (150) has a relationship indicated by Equation 1: αw <α1 < α2 (Equation 1)