Double Eccentric Bushing Alignment for Misaligned Bolt Holes

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Solution Overview

Problem

Existing methods for attaching multi-hole components face challenges with misalignment and free-play due to tight tolerances, which can lead to improper bolt preload and loss during service.

Innovation Solution

A fastener aligning joint arrangement using double eccentric bushings with washers and snap rings, allowing for step-less adjustment and alignment of fasteners within oversized apertures, enabling precise positioning and maintaining tight clearances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If tight tolerances are used to ensure hole alignment, then manufacturing precision is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improvehole alignmentVSAvoidmanufacturing difficulty

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The alignment function is segmented between the component holes and the eccentric bushings. The bushings act as independent alignment elements that can be rotated to match misaligned holes, eliminating the need for tight manufacturing tolerances on the holes themselves.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The eccentric bushings provide adjustable rotational parameters that allow alignment compensation. By rotating the bushings to different angular positions, misalignment between holes can be compensated without requiring precise manufacturing of the holes.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If oversized bolt holes are used to compensate for misalignment, then ease of manufacture is improved, but reliability deteriorates due to free-play

Engineering Contradiction:

Improvehole manufacturingVSAvoidfree-play

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The eccentric bushings serve as intermediary elements between the oversized holes and the fasteners. They maintain a constant radius that eliminates free-play while allowing the oversized holes to accommodate misalignment, thus resolving both the ease of manufacture and reliability concerns.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If elongated slots are used for bolt insertion, then ease of manufacture is improved, but reliability deteriorates due to free-play

Engineering Contradiction:

Improveslot manufacturingVSAvoidfree-play

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The eccentric bushings act as intermediary elements that replace the need for elongated slots. They provide precise circular alignment while accommodating misalignment through rotation, eliminating the free-play associated with slot-based alignment methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If double eccentric bushings are used for alignment, then reliability is improved by reducing free-play, but device complexity increases

Engineering Contradiction:

Improvefree-play reductionVSAvoidbushing arrangement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The double eccentric bushing arrangement uses nested concentric bushings where one eccentric bushing is positioned within another. This nested configuration allows both bushings to rotate independently to accommodate misalignment while maintaining constant radius alignment, reducing free-play without requiring overly complex external structures.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 solution effectively reduces free-play and allows for precise alignment and adjustment of fasteners, ensuring secure attachment and maintaining tight clearances in multi-hole assemblies, even in scenarios with significant hole misalignment.

Implementation Method 1

a first eccentric bushing comprising a first eccentric aperture, the first component is configured to receive the first eccentric bushing in the oversized aperture

Methodology Applied

Scientific EffectEccentric: Excentric

Data Source

PatentUS11905985B2Systems and methods for misalignment adjustment utilizing double eccentric bushings

Publication Date: 2024.02.20 GOODRICH CORP

AI summary

A double eccentric bushing arrangement comprises a first eccentric bushing comprising a first eccentric aperture, a second eccentric bushing comprising a second eccentric aperture, a fastener, a washer configured to be received around a portion of the second eccentric bushing, and a snap ring configured to be received around a portion of the second eccentric bushing to secure the washer in an installed position. The first eccentric bushing is configured to receive the second eccentric bushing in the first eccentric aperture. The second eccentric bushing is configured to receive the fastener in the second eccentric aperture. The first eccentric bushing is rotatable with respect to the second eccentric bushing to adjust a position of the fastener with respect to an adjacent component to which the fastener is being attached.