Wheel End Hub Casing Sealing Across Mixed-Material Interfaces
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Solution Overview
Problem
The existing wheel end hubs with lightweight outer bodies and hard inner cores face challenges in maintaining a water-tight seal due to differences in material properties and tolerances, leading to potential moisture ingress.
Innovation Solution
A wheel end assembly design where two materials are joined to form a single piece with different axial extensions, allowing a sealing contact with only one material, using an annular seal that extends radially from the wheel end bearing towards and into contact with one of the materials, thereby sealing off the interface between them.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing gasket stretches across both the outer body and inner core to seal the interface, then sealing coverage is improved, but the risk of water or moisture seepage increases due to differential movement between the two materials
Solution Approach 1:
The sealing function is segmented into two separate sealing contacts: one sealing contact on the outer body and another sealing contact on the inner core. This segmentation allows each seal to independently contact a single material surface, eliminating the problem of differential movement between materials that causes seal failure.
Solution Approach 2:
The seal acts as an intermediary element that creates two separate sealing interfaces rather than one continuous interface spanning both materials. This intermediary approach allows the seal to accommodate the different thermal expansion and movement characteristics of the two materials by making separate contact points.
2Reliability
If a single continuous sealing gasket is used across the interface, then sealing continuity is improved, but manufacturing precision requirements increase due to tolerance accumulation between different materials
Solution Approach 1:
The sealing path is segmented into separate contact zones on the outer body and inner core. This segmentation breaks the continuous sealing requirement into discrete sealing points, thereby reducing the cumulative tolerance requirements across the entire interface.
Solution Approach 2:
The seal is designed to create localized sealing contacts at specific positions on the outer body and inner core rather than requiring uniform sealing across the entire interface. This local quality approach allows for greater tolerance in non-critical areas while maintaining effective sealing at the designated contact points.
Data Source
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AI summary
The invention relates to a wheel end assembly for a vehicle, comprising a wheel end bearing, a hub casing including a first material and a different second material joined together as a single piece, the hub casing comprising a radially external body of said first material and a radially internal tubular core of said second material, the tubular core being provided concentrically around the wheel end bearing, and an annular seal which is concentric with the wheel end bearing and the hub casing, wherein the annular seal has a radial extension from the wheel end bearing towards and into contact with one of the external body and the tubular core, and wherein the annular seal is spaced apart from the other one of the external body and the tubular core. The invention also relates to a wheel end arrangement and to a vehicle.