Composite Oil Seal With Plastic Inner Cup And Stiffening Ribs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing oil and grease seals for large trucks and semi-trailers face challenges with plastic outer cups lacking stiffness and failing to properly seat due to deformation under assembly force, while metal inner cups are heavy and costly, and no efforts have been made to use plastic for inner cups, which require different properties.
Innovation Solution
A unitized seal design combining a metal outer cup with a plastic inner cup featuring regularly spaced stiffening ribs and notched areas for added support, reducing noise and weight, and allowing for complex shapes and manufacturing flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the outer cup is made from plastic material, then manufacturing cost is reduced and design flexibility is improved, but the cup lacks necessary stiffness and deforms under assembly force
Solution Approach 1:
The patent applies composite materials by combining plastic outer cup with metal inner cup and metal stiffening ribs. The plastic provides corrosion resistance and manufacturing flexibility, while the metal components provide the necessary structural strength and stiffness. This composite structure resolves the contradiction between ease of manufacture and strength.
2Reliability
If the outer cup is dimensioned with interference fit, then sealing effectiveness is improved, but the plastic cup collapses or deforms during assembly
Solution Approach 1:
The metal inner cup acts as an intermediary between the plastic outer cup and the seal-receiving opening. It provides a rigid interface that can withstand interference fit forces without deforming, while the plastic outer cup maintains its sealing function. This intermediary structure resolves the contradiction between sealing effectiveness and structural integrity.
3Strength
If the inner cup is made from metal, then structural strength is ensured, but weight and manufacturing cost increase
Solution Approach 1:
The patent applies local quality by using metal only where structurally necessary (inner cup and stiffening ribs) and plastic where weight reduction is beneficial (outer cup). This localized material distribution provides structural strength at minimal weight, resolving the contradiction between strength and weight.
4Weight of moving object
If the inner cup is made from plastic, then weight and cost are reduced, but manufacturing complexity increases due to required stiffening structures
Solution Approach 1:
The patent applies segmentation by dividing the inner cup structure into multiple components: plastic outer cup, metal inner cup, and metal stiffening ribs. This segmentation allows each component to be optimized for its specific function and manufactured using appropriate processes, reducing overall manufacturing complexity while maintaining weight benefits.
Data Source
AI summary
A heavy duty composite oil seal with an outer cup and a plastic inner cup. The outer cup includes a major diameter mounting flange portion terminating in a curl, a minor diameter wear sleeve portion, and a transition portion joining the major and minor diameter portions. There is an elastomeric seal body and an embedded stiffener, with the elastomeric seal body having a sealing lip contacting the inner axial surface of the wear sleeve portion. There is a plastic inner cup member with an axial flange substantially co-extensive with the mounting flange and entrapped along the major diameter flange portion between the curl portion and the transition portion of the outer cup. The inner cup also has a radially extending flange that engages a radial portion of the elastomeric seal body. The plastic inner cup member has plural, evenly spaced diagonal braces extending between and joining the axial flange and the radial flange of the inner cup.