Aircraft Wheel Grease Retainer Using Pliable Interface Rings

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Aircraft wheel systems face grease loss due to centrifugal and other forces, leading to potential bearing failure, safety issues, and increased maintenance costs, as existing grease retainers require machining and specific register widths, making them unsuitable for many existing wheel assemblies.

Innovation Solution

A cylindrical retaining structure with pliable interface rings, such as O-rings, that spans between the outer and inner wheel halves, providing a grease retainer system that does not require machining and can fit within existing wheel assemblies without sufficient register width, using a molded or machined design with C- or L-shaped flanges to prevent grease migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional elastomeric grease retainers are used, then grease retention is improved, but wheel assembly complexity increases due to required machined grooves and register widths

Engineering Contradiction:

Improvegrease retentionVSAvoidwheel assembly structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a flexible elastomeric grease retainer ring that can deform to fit within the bearing cavity without requiring rigid machined grooves. The retainer ring's flexibility allows it to conform to the cavity walls and maintain grease containment while adapting to variations in cavity dimensions, thereby improving grease retention without increasing wheel assembly structural complexity.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The grease retainer ring is designed as a simple, inexpensive elastomeric component that can be easily replaced during maintenance. This disposable approach eliminates the need for complex permanent retention structures, reducing overall device complexity while maintaining reliable grease retention throughout the retainer's service life.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If grease retainers are added to existing wheel assemblies, then grease retention is improved, but manufacturing costs increase due to retrofit machining requirements

Engineering Contradiction:

Improvegrease retentionVSAvoidretrofit cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The grease retention function is separated from the wheel assembly structure itself and implemented as a distinct, standalone elastomeric retainer ring. This segmentation allows the retainer to be installed independently without modifying the wheel assembly, eliminating retrofit machining costs while maintaining effective grease retention in existing assemblies.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The elastomeric retainer ring acts as an intermediary component between the bearing grease and the wheel assembly cavity. It provides the grease retention function without requiring direct structural integration or machining of the wheel assembly, thereby enabling cost-effective retrofitting of existing assemblies.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If existing wheel assemblies are modified to accept retainers, then grease retention is improved, but installation time increases due to disassembly and machining

Engineering Contradiction:

Improvegrease retentionVSAvoidinstallation time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The elastomeric retainer ring is pre-formed and ready for installation without requiring any preparation or machining of the wheel assembly. The bearing cavity dimensions are designed to directly accommodate the retainer ring, eliminating the need for time-consuming disassembly and machining operations during retrofit or initial installation.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If machined grooves are added for retaining rings, then grease retention is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvegrease retentionVSAvoidgroove width tolerance

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the retention mechanism from relying on precise rigid groove dimensions to using the elastic properties of the elastomeric retainer ring. The retainer ring's ability to deform and conform to the bearing cavity eliminates strict groove width tolerance requirements, reducing manufacturing precision demands while maintaining effective grease retention.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7658451B2Aircraft wheel grease retainer and method for retrofitting the same

Publication Date: 2010.02.09 GOODRICH CORP

AI summary

An aircraft wheel grease retainer for use in a wheel assembly having an axis of rotation, and further having bearings which are each located in a bearing cavity, wherein the bearing uses grease, which is introduced into the bearing cavity, wherein the wheel assembly is comprised of an outer wheel half assembly, and an inner wheel half assembly, wherein the grease retainer comprises a cylindrical retaining structure which spans from the bearings on the outer wheel half assembly to the bearings on the inner wheel half assembly, and two pliable interface rings. The cylindrical retaining structure has a centerline which corresponds to the wheel assembly axis of rotation, and further has an outer end and an opposing inner end, with a corresponding outer retaining flange and inner retaining flange which extend over the bearing cavities. The pliable interface rings seat on the cylindrical retaining structure, and interface between the cylindrical retaining structure and the wheel assembly.