Journal Bearing Backing Ring Sealant Design

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Solution Overview

Problem

Existing roller bearing assemblies for rail car axles face challenges in preventing water and contaminants from entering the sealed bearing area, particularly between the shaft and the backing ring, due to gaps and lack of effective sealing mechanisms.

Innovation Solution

The implementation of an annular sealant bead or sealant rings, such as silicone or nitrile rubber, between the shaft shoulder and the backing ring, and between the wear ring and the backing ring, to create a seal that prevents water and abrasives from entering the bearing assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If no sealant is used between the shaft and backing ring, then the structure is simple and easy to manufacture, but water and contaminants can enter the bearing assembly

Engineering Contradiction:

Improvesealing effectivenessVSAvoidsealing structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

An annular sealant bead or sealant rings are introduced as an intermediary substance between the shaft shoulder and the backing ring to create an effective seal. This sealant fills the gap and prevents water and contaminants from entering the bearing assembly, resolving the contradiction by adding a simple sealing element rather than a complex sealing mechanism

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealant rings made of flexible materials like nitrile rubber create a flexible sealing barrier between the shaft and backing ring. This flexible seal adapts to slight variations in the interface geometry while maintaining effective sealing, preventing contaminant ingress without requiring precise machining or complex sealing structures

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If a sealant bead is added between the shaft shoulder and backing ring, then sealing is improved, but the manufacturing process becomes more complex

Engineering Contradiction:

Improvecontaminant protectionVSAvoidassembly process simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The sealant bead is applied in advance to the shaft shoulder or backing ring surface before final assembly. This preliminary sealing action ensures that the seal is in place before the bearing assembly is fully installed, making the sealing process simpler and more reliable than attempting to install seals during final assembly

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sealant rings are made from inexpensive materials like nitrile rubber and can be easily replaced if needed. This approach prioritizes ease of manufacture and maintenance over using expensive, permanent sealing solutions, allowing for simple replacement rather than complex repair procedures

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS7534047B2Journal bearing backing ring

Publication Date: 2009.05.19 AMSTED RAIL CO INC

AI summary

A bearing assembly is provided having a roller bearing with an inner case fitted around the journal portion of an axle. An outer raceway combines with the inner raceway to receive roller elements. A backing ring is centered to the shaft fillet. An annular wear ring is positioned between the inner case and the backing ring. An annular sealant bead or a sealant ring form a seal between the shaft shoulder and the backing ring.