Bellows Screw Sleeve for Tolerance Compensation

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Solution Overview

Problem

Existing flow meters and screw sleeves fail to effectively compensate for tolerances in components to be screwed, leading to potential electrical and magnetic contact between screws and core laminations, which can result in insulation failures.

Innovation Solution

A screw sleeve designed to axially shorten and deform into a bellows shape under axial force, using a polymer material like polyethersulfone, with a reduced wall thickness ring that assumes a bellows form to maintain electrical and magnetic insulation while accommodating component tolerances, and is simpler and cheaper to manufacture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a standard rigid screw sleeve is used to insulate screws, then electrical and magnetic insulation is provided, but it cannot compensate for tolerance variations in the components being screwed

Engineering Contradiction:

Improveinsulation integrityVSAvoidtolerance compensation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The screw sleeve incorporates a bellows structure with axial flexibility that allows the sleeve to deform and adapt to tolerance variations in the core laminations thickness while maintaining continuous electrical and magnetic insulation between the screw and the core laminations

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The screw sleeve transitions from a rigid structure to a dynamic flexible structure capable of axial deformation. The bellows design enables the sleeve to dynamically adjust its length to accommodate tolerance variations during assembly while preserving insulation integrity

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the screw sleeve is made axially flexible to compensate for tolerances, then tolerance compensation is achieved, but the insulation reliability may be compromised

Engineering Contradiction:

Improvetolerance compensationVSAvoidinsulation integrity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The bellows structure is designed as a flexible yet continuous insulating barrier that maintains electrical and magnetic isolation between the screw and core laminations even during axial deformation, ensuring that flexibility does not compromise insulation reliability

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The screw sleeve uses polymer materials that combine electrical and magnetic insulation properties with axial flexibility. This composite material approach allows the sleeve to simultaneously provide reliable insulation and tolerate axial deformations required for compensation

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If a complex deformation structure is used to compensate for tolerances, then tolerance compensation is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvetolerance compensationVSAvoidscrew sleeve structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The bellows structure is formed as an integrated feature of the screw sleeve rather than a separate component. This single-piece flexible design achieves tolerance compensation through axial deformation while avoiding the need for multiple parts or complex assembly procedures

Inventive Principle:

Principle #30Flexible shells and thin films

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 screw sleeve effectively compensates for component tolerances, ensuring electrical and magnetic insulation between screws and core laminations, preventing contact and maintaining insulation integrity during assembly and operation.

Implementation Method 1

The inventive deformation of the screw sleeve 1 to form a bellows is elastic or partially plastic

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The inventive deformation of the screw sleeve 1 to form a bellows is elastic or partially plastic

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Implementation Method 3

A screw sleeve according to the invention comprises in particular a polymer material such as polyethersulfone. Alternative materials are, for example, polyetaacetone or polyphenylene sulfide. The screw sleeves are therefore electrically and possibly magnetically insulating

Methodology Applied

Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 4

Methodology Applied

Scientific EffectMagnetic insulation: Magnetic Field

Data Source

PatentEP2761192B1Screw bushing

Publication Date: 2017.05.10 ENDRESS HAUSER FLOWTEC AG

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AI summary

The invention relates to a screw bushing (1) for insulating a screw (8), designed such that it reduces axially by a predefined length when a force having a predetermined size is exerted axially thereon, said screw bushing adopting at least partially the shape of a bellows (5).