Segmented Axial Seal for Linkage Joint Contaminant Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In joint assemblies of linkages, such as those in construction vehicles, the axial space between components can allow contaminants to enter due to relative radial displacement, which existing shims fail to adequately prevent.

Innovation Solution

A seal comprising a generally annular seal body with radial and circumferential sealing surfaces is used to enclose the axial space, optionally split to facilitate assembly, and includes features like shim cavities and engagement tabs to securely engage with shims and maintain sealing, accommodating varying axial space widths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shims are used to occupy axial space, then axial displacement is prevented, but contaminant protection is insufficient

Engineering Contradiction:

Improveaxial displacement preventionVSAvoidcontaminant entry

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a flexible seal member (elastomeric or polymeric material) that forms a continuous barrier across the axial space between the pin and boss. This flexible membrane-like structure completely blocks contaminant pathways while accommodating radial movements, unlike rigid shims that leave gaps.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The seal member is divided into multiple segments or lobes (typically three to six) arranged radially around the axial space. Each segment independently contacts the pin and boss surfaces, creating multiple sealing zones that collectively prevent contaminant ingress while allowing radial displacement.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If a continuous seal body is used to enclose axial space, then contaminant protection is improved, but assembly difficulty increases

Engineering Contradiction:

Improvecontaminant protectionVSAvoidassembly difficulty

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The seal body is segmented into multiple identical or similar sections arranged radially around the axial space. This segmentation allows the seal to be assembled in a split configuration, with each segment independently positioned and secured, greatly simplifying installation compared to a single continuous seal ring.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The segmented seal structure allows inner components (such as retainers or mounting features) to be nested within or between the seal segments during assembly. The segments can be stacked or interlocked in a nested manner, facilitating compact assembly and simplifying the overall installation process.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS8794862B2Seal for sealing an axial space

Publication Date: 2014.08.05 AB SKF SKF PATENT DEPARTMENT

AI summary

A seal is for sealing an axial space between first and second axially-spaced members, the first member having a radial surface and the second member having an outer circumferential surface. The seal includes an annular body having inner and outer circumferential surfaces and first and second axial ends, a radial sealing surface proximal to the first end to sealingly engage with the first member radial surface, and a circumferential sealing surface proximal to the second end to sealingly engage with the second member outer surface. At least a portion of the seal body extends circumferentially about and encloses the axial space. The seal may be incorporated in a joint assembly for a linkage having first and second links, the assembly including a shaft coupled with the first link and a boss coupled with the second link, receiving the shaft, and defining an axial space in which the seal is disposed.