Optical Component Mounting with Thermal Expansion Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing optical component mounts face issues with stress and cracking due to temperature fluctuations caused by mismatched thermal expansion coefficients between the optical components and their surrounding materials, leading to complex dimensioning and unsuitability for sealed enclosures.

Innovation Solution

A two-part mount housing design where one part is a ring encompassing the optical component with a groove for a clamping ring, featuring a thin-walled housing web as an elastically deformable joint, allowing for thermal expansion compensation and sealed enclosure, with the clamping ring designed to manage thermal expansion differently than the housing ring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a two-part housing with different coefficients of thermal expansion is used to compensate for thermal expansion, then thermal stress on the optical component is reduced, but the dimensioning of connecting ribs becomes very complex

Engineering Contradiction:
Improvethermal stress compensationVSAvoiddimensioning of connecting ribs
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The housing is divided into two separate parts: an annular housing part and a clamping ring, each made of materials with different coefficients of thermal expansion. This segmentation allows each part to be optimized independently for thermal compensation while simplifying the overall design compared to complex rib structures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the material parameters (coefficients of thermal expansion) of the two housing parts to be different from each other and from the optical component. This parameter change enables automatic thermal expansion compensation without complex dimensional calculations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the optical component is held in the housing by spaced-apart ribs, then thermal expansion compensation is achieved, but the housing cannot provide a sealed enclosure

Engineering Contradiction:
Improvethermal expansion compensationVSAvoidenvironmental sealing
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The clamping ring is merged with the annular housing part through a continuous groove that circumscribes the optical component, creating a unified structure that provides both thermal compensation and sealed enclosure. The groove allows the clamping ring to be pressed into the housing part, forming a tight seal.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The groove is designed with a small cross-section that allows the clamping ring to be pressed into it, creating a flexible seal that can accommodate thermal expansion while maintaining environmental sealing. The thin-walled design of the groove area provides elastic deformability.

Inventive Principle:
Principle #30Flexible shells and thin films

3Strength

If both the housing part and clamping ring bear directly against the optical component, then secure mounting is achieved, but temperature-related stresses directly affect the optical component

Engineering Contradiction:
Improvemounting securityVSAvoidoptical component stress
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The groove acts as an intermediary element between the clamping ring and the optical component. It allows the clamping ring to bear against the housing part while the housing web provides a compliant interface that prevents direct stress transmission to the optical component.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The thin-walled housing web forming the groove provides a flexible interface that can deform elastically under thermal expansion, preventing the transmission of temperature-related stresses to the optical component while still maintaining secure mounting through the clamping ring.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If a thin-walled housing web is used to separate the groove from the optical component, then thermal stress is minimized, but the structural strength of the housing part is reduced

Engineering Contradiction:
Improvethermal stress minimizationVSAvoidhousing part structural strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The housing part is designed with non-uniform wall thickness: thin-walled in the groove area to minimize thermal stress and allow elastic deformation, and thicker in other areas to maintain overall structural strength. This local variation in quality optimizes both thermal compensation and structural integrity.

Inventive Principle:
Principle #3Local quality

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

This design minimizes stress on the optical component by allowing for low-stress, sealed enclosures with effective thermal expansion compensation, reducing the risk of cracking and ensuring compatibility with varying thermal expansion coefficients.

Implementation Method 1

the two housing parts have different coefficients of thermal expansion

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the groove is separated from the optical component and from the outside of the housing only by a thin-walled housing web forming a solid-body hinge, which forms an elastically deformable bending point

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the groove surrounds the optical component all around, wherein the groove near the optical component is designed and dimensioned in such a way that the groove is separated from the optical component and from the outside of the housing only by a thin-walled housing web forming a solid-body hinge, which forms an elastically deformable bending point

Methodology Applied
Scientific EffectThermal expansion compensation: Thermal Expansion

Implementation Method 4

a clamping or pressure ring to be pressed into this ring, achieving expansion compensation by clamping the two components

Methodology Applied
Scientific EffectClamping force: Mechanical Force

Data Source

PatentEP2221651B1Mounting for optical components
Publication Date: 2020.10.21 KARL STORZ SE & CO KG
  • EP2221651B1 patent drawingFigure 1
  • EP2221651B1 patent drawingFigure 2
  • EP2221651B1 patent drawingFigure 3~4

AI summary

The holder has a two-part capsule type holder housing (2) encompassing an optical component (3) in a circular manner. Two housing parts (6, 7) exhibit different heat expansion co-efficients. One of the housing parts (6) is designed as a ring that encompasses the optical component. A circular groove is formed at a housing inner side proximity to the optical component, where the groove surrounds the optical component. The groove serves for holding another housing part (7) designed as clamping or press rings, which are designed as massive clamping rings or toothed press rings.