Tripod Seal Adapter Root Geometry for Grease Leakage
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Solution Overview
Problem
Existing adapters for sealing the outer joint portion of constant velocity joints, particularly tripod joints, face challenges in achieving a complete seal due to the geometry of the tulip minor surface portion, especially at the root portion, where the sealing bead does not always contact and seal effectively, leading to grease leakage and contamination ingress.
Innovation Solution
The adapter features a main body with an inner sealing surface that includes a plurality of track and root portions, where each root portion has a root midpoint and two track connecting points, with a first and offset root radius, and is integrated with a first and second sealing bead, along with a center profile, to enhance sealing at the tulip minor surface portion, ensuring a more comprehensive seal is maintained.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the adapter is constructed from flexible rubber material, then the adapter can deform to conform to the tulip shape, but the sealing bead does not always contact and seal along the outer profile of the tulip, especially at the root portion
Solution Approach 1:
The patent applies local quality by creating distinct root portions with different geometric properties along the inner sealing surface. Each root portion has a root midpoint and two track connecting points, with the root midpoint being offset from the centerline. This local geometric variation ensures that the flexible rubber material deforms differently at each location, guaranteeing contact at the root portions where sealing is most critical, while maintaining overall adapter flexibility.
Solution Approach 2:
The patent utilizes curvature principles by defining the inner sealing surface with specific radii of curvature. The root portions have defined root radii that create curved sealing surfaces, allowing the flexible rubber adapter to deform and conform to the curved outer profile of the tulip, ensuring reliable sealing contact throughout the sealing interface.
2Force
If the clamp applies pressure to compress the boot and adapter against the tulip, then the seal is improved, but the root portion receives the least amount of pressure and does not seal effectively
Solution Approach 1:
The patent applies asymmetry by offsetting the root midpoints from the centerline of the adapter. This asymmetric positioning of the root portions along the inner sealing surface ensures that when the clamp applies pressure, the geometry of the offset root portions directs and concentrates sealing pressure at these critical locations, overcoming the tendency for root portions to receive the least pressure in symmetric designs.
Solution Approach 2:
The patent creates local quality variations in the inner sealing surface geometry, with each root portion having specific offset dimensions and radii. This local geometric differentiation ensures that pressure from the clamp is distributed non-uniformly, with enhanced pressure concentration at the root portions where sealing reliability is most needed, rather than uniform pressure distribution.
3Ease of manufacture
If the inner sealing surface geometry is simplified, then the adapter is easier to manufacture, but the sealing performance at the root portion is compromised
Solution Approach 1:
The patent applies segmentation by dividing the inner sealing surface into distinct segments: track portions and multiple root portions. Each root portion is further segmented into a root midpoint and two track connecting points. This segmentation allows for standardized manufacturing of each segment while achieving complex sealing geometry, as each segment can be formed using standard molding techniques and then assembled or integrated into the complete adapter.
Solution Approach 2:
The patent utilizes parameter changes by defining specific geometric parameters for the root portions, including offset distances from the centerline, root radii, and angles. These parameters can be adjusted during the molding process to achieve the desired sealing geometry without requiring complex post-manufacturing operations, thus maintaining ease of manufacture while improving sealing performance.
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 enhanced sealing design effectively reduces grease leakage and contamination ingress by ensuring a complete seal along the tulip minor surface, even at the root portion, improving the adapter's sealing performance, especially when constructed from flexible materials like rubber.
Implementation Method 1
the bead deforms against the outer profile of the tulip, forming a seal between the adapter and the tulip
Implementation Method 2
The adapter may not contact the tulip at the root positions of the adapter especially if the adapter is constructed from a flexible, rubber-based material
Data Source
AI summary
An adapter for sealing an outer joint portion of a joint assembly, the adapter includes a main body having an aperture for receiving an outer joint portion, the aperture including an inner sealing surface. The inner sealing surface has a plurality of track portions and a plurality and root portions, where each root portion includes a root midpoint and two track connecting points. The track connecting points connect the root portion to the track portion. The root portion includes a first root radius and an offset root radius, where the first root radius is measured from a first center, and the offset root radius is measured from an offset center. The offset center is located closer to the center axis of the adapter than the first center. Each root portion includes the first root radius at the track connecting point, and gradually transitions to the offset root radius.