Seal Assembly for Track Pin Joint with Convex Load Ring
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Solution Overview
Problem
Current can-type seals in track chains are prone to 'heel under' failures due to debris ingestion between the load ring and the seal cavity, leading to lubricant leakage and accelerated wear.
Innovation Solution
A load ring with a convex rounded axial segment and a neck portion that changes angle between the uninstalled and installed states, combined with a seal assembly featuring a seal ring and a load ring, provides enhanced sealing by distributing compressive strain and resisting debris ingestion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional can seal is used in a track chain, then the seal provides basic sealing function, but debris is ingested between the load ring and seal cavity causing heel under failures
Solution Approach 1:
The load ring engagement surface includes a convex rounded portion extending over at least half the length of the upper segment. This curved geometry prevents debris from being trapped between the load ring and seal cavity, eliminating the heel under failure mode while maintaining effective sealing between track chain components.
Solution Approach 2:
The engagement surface is designed with different geometries in different regions: a convex rounded portion in the upper segment and a radial segment in the lower segment. This localized variation in surface geometry optimizes both debris prevention and sealing effectiveness at different positions of the load ring.
2Ease of manufacture
If the load ring engagement surface is made flat, then manufacturing is simpler, but compressive strain is not properly distributed leading to seal failure
Solution Approach 1:
The convex rounded portion on the load ring engagement surface provides a curved contact interface that naturally distributes compressive strain along the arc of contact. This curved geometry achieves superior strain distribution compared to flat surfaces while remaining compatible with standard manufacturing processes.
3Strength
If the neck portion is rigid, then structural strength is maintained, but the seal cannot adapt to installation variations and stress concentrations occur
Solution Approach 1:
The neck portion is designed with curved geometry that allows it to flex and adapt during installation. The curved shape enables the neck to accommodate variations in assembly alignment and distribute stresses more evenly, while the overall structural integrity is maintained through the optimized curvature and transition to the main body.
Data Source
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AI summary
A seal assembly can be incorporated into a track pin joint assembly including a pin defining a longitudinal axis, a first member and a second member both coaxial with the pin about the longitudinal axis. The first member is pivotable about the longitudinal axis with respect to the second member and includes a load ring engagement surface defining, at least in part, an axially- extending seal cavity disposed in proximal relationship to the second member. A seal assembly including a seal ring and a load ring is disposed in the seal cavity and sealingly engages the first member and the second member. At least one of a load ring engagement surface of the first member and an axial segment of a first member engagement surface of the load ring includes a convex rounded portion extending over at least half the axial length thereof.