Offset-Bore Journal Bearing for Centering Misaligned Pins

Solution Overview

Problem

Misaligned shear pins in aircraft electrical equipment racks cause interference preloads, leading to deformation of bushings and objectionable sounds during flight due to excessive misalignment between the floor shear plate and electrical equipment racks.

Innovation Solution

A journal bearing with an outer and inner bushing, both offset relative to the axis of rotation, which are configured to rotate relative to each other to center the inner periphery around the misaligned pin, thereby removing pre-load forces against the shear plate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a bushing is placed between the shear pin and the floor shear plate to accommodate misalignment, then the misalignment is supposed to be accommodated, but the bushing experiences interference preloads due to excessive misalignment, causing deformation and objectionable sounds

Engineering Contradiction:

Improveaccommodation of misalignmentVSAvoidinterference preloads causing deformation and sounds

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The journal bearing is segmented into an outer bushing and an inner bushing that can rotate independently relative to each other. The outer bushing remains stationary within the counterbore, while the inner bushing rotates to center the misaligned pin, dividing the alignment function between two separate components

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner bushing is designed to rotate dynamically relative to the outer bushing to accommodate and center the misaligned pin. This dynamic rotation allows the system to adapt to misalignment conditions without creating interference preloads, transforming a static rigid connection into a dynamic adjustable mechanism

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the bushing is designed to accommodate misalignment, then adaptability is improved, but the bushing becomes deformed under excessive misalignment preloads

Engineering Contradiction:

Improvemisalignment accommodation capabilityVSAvoidbushing structural integrity

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The journal bearing is segmented into an outer bushing and an inner bushing that can rotate independently relative to each other. The outer bushing remains stationary within the counterbore, while the inner bushing rotates to center the misaligned pin, dividing the alignment function between two separate components

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner bushing is designed to rotate dynamically relative to the outer bushing to accommodate and center the misaligned pin. This dynamic rotation allows the system to adapt to misalignment conditions without creating interference preloads, transforming a static rigid connection into a dynamic adjustable mechanism

Inventive Principle:

Principle #15Dynamics

3Manufacturing precision

If a journal bearing with offset bores is used to center the misaligned pin, then the misalignment is effectively corrected, but the device complexity increases

Engineering Contradiction:

Improvepin centering accuracyVSAvoidjournal bearing structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The journal bearing is segmented into an outer bushing and an inner bushing that can rotate independently relative to each other. The outer bushing remains stationary within the counterbore, while the inner bushing rotates to center the misaligned pin, dividing the alignment function between two separate components

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner bushing is designed to rotate dynamically relative to the outer bushing to accommodate and center the misaligned pin. This dynamic rotation allows the system to adapt to misalignment conditions without creating interference preloads, transforming a static rigid connection into a dynamic adjustable mechanism

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11566651B2Journal bearing with offset bores for centering a misaligned pin

Publication Date: 2023.01.31 THE BOEING CO

AI summary

A journal bearing for centering a misaligned pin is disclosed. The journal bearing includes an outer bushing defining an outer bore. The outer bore is offset with respect to an axis of rotation of the journal bearing by a misalignment distance. The misalignment distance represents a distance between the axis of rotation of the journal bearing and a center axis of the misaligned pin. The journal bearing further includes an inner bushing defining an inner bore. The inner bore is offset with respect to the axis of rotation of the journal bearing by the misalignment distance. The inner bushing is seated within the outer bore of the outer bushing. The inner bushing and the outer bushing are both configured to rotate relative to one another to center an inner periphery of the inner bushing around the misaligned pin.