Wheel End Assembly Compression Ring Seal Integrity

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Solution Overview

Problem

The existing wheel end assemblies face issues with the seal assembly's integrity due to thermal expansion differences between the hub and the seal case, leading to a loose fit and potential rotation of the hub relative to the seal case, which can compromise structural integrity.

Innovation Solution

A compression ring is disposed on the hub, exerting a radial compressive force on the mounting ring to maintain an interference fit between the outer seal case and the hub, and is assembled by heating and cooling to ensure a stable radial inward force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the hub and seal case are assembled with a clearance fit, then assembly is easier, but thermal expansion causes a loose fit and potential rotation compromising structural integrity

Engineering Contradiction:
Improveassembly easeVSAvoidseal assembly integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The compression ring is pre-loaded onto the hub before final assembly, creating an interference fit that maintains constant contact pressure between the seal case and hub. This preliminary action ensures that thermal expansion does not create clearance or rotation during operation, while the modular design with the compression ring still allows for practical assembly procedures

Inventive Principle:
Principle #10Preliminary action

2Reliability

If an interference fit is used between hub and seal case, then structural integrity is maintained, but assembly becomes difficult

Engineering Contradiction:
Improveseal assembly integrityVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sealing system is segmented into three components: the hub, the seal case, and the compression ring. This segmentation allows the compression ring to be installed separately on the hub, creating a pre-loaded interference fit that maintains structural integrity while simplifying the overall assembly process through modular installation

Inventive Principle:
Principle #1Segmentation

3Reliability

If the compression ring exerts high radial compressive force, then thermal expansion is reduced and seal integrity is maintained, but stress on the hub increases

Engineering Contradiction:
Improveseal assembly integrityVSAvoidradial compressive force on hub
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The compression ring's geometry and material properties are optimized to distribute the radial compressive force evenly around the hub circumference. The ring's cross-sectional area and elastic modulus are selected to achieve the required contact pressure without exceeding the hub's stress limits, maintaining seal integrity while protecting the hub from excessive stress

Inventive Principle:
Principle #35Parameter changes

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 compression ring effectively reduces thermal expansion of the hub, maintaining the seal assembly's integrity and preventing rotation, thereby enhancing the structural integrity and preventing contaminants from entering or escaping.

Implementation Method 1

heating a compression ring to expand the compression ring

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

cooling the compression ring so that the compression ring exerts a radially inward force on the hub

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP3398835B1Wheel end assembly having a compression ring and method of assembly
Publication Date: 2019.10.23 ARVINMERITOR TECHNOLOGY LLC
  • EP3398835B1 patent drawingFigure 1
  • EP3398835B1 patent drawingFigure 2
  • EP3398835B1 patent drawingFigure 3

AI summary

A wheel end assembly having a steering knuckle, a hub, and a compression ring. The steering knuckle may have an opening that may extend around a spindle. The hub may be rotatably disposed on the spindle. The compression ring may be disposed on the hub and may be at least partially disposed in the opening.