Radial Shaft Seal Elastomer Creep Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radial shaft seals using polyfluorocarbons like polytetrafluoroethylene face challenges with material creep leading to decreased sealing effectiveness and increased wear, requiring a balance between tightness and wear that is difficult to achieve, and existing solutions often involve complex and costly additives or heat dissipation issues.
Innovation Solution
The shaft seal design incorporates an elastomer element that ensures the sealing lip maintains sufficient contact pressure despite material creep, with a support element like an annular disk securely holding the sealing element in place, allowing for compact, cost-effective production and reliable sealing performance across various conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the radial preload acting on the sealing lip is increased to counteract creeping effect, then the sealing effectiveness is improved, but the wear of the sealing lip increases correspondingly
Solution Approach 1:
The sealing element is made from a composite material consisting of polyfluorocarbon base material combined with at least one of glass fibers, carbon fibers, or bronze particles. This composite structure provides both the creep resistance needed for effective sealing and the mechanical strength to reduce wear, allowing the sealing lip to maintain its functionality throughout the entire service life of the shaft seal.
2Reliability
If different fillers are added to the sealing element to achieve balance between tightness and wear, then the sealing performance is improved, but the production becomes complex and expensive
Solution Approach 1:
The invention modifies the material parameters of the sealing element by incorporating specific filler materials (glass fibers, carbon fibers, or bronze particles) within defined size ranges (0.1-5 mm for fibers, 0.01-1 mm for particles) and concentration ranges (1-50% by weight). These parameter changes optimize both sealing performance and wear resistance while maintaining manufacturability through standardized production processes.
3Stability of the object's composition
If the sealing element is axially clamped between support elements, then the sealing element is securely positioned, but the heat dissipation is impaired leading to premature wear
Solution Approach 1:
The support elements are designed with differentiated local properties: the first support element (annular disk) provides axial clamping and positioning stability, while the second support element (radially extending support) creates intentional spacing that allows heat dissipation pathways. This local differentiation of support functions ensures both secure positioning and adequate thermal management.
4Reliability
If a two-part housing encapsulates the sealing elements and elastomer element, then the sealing structure is protected, but the heat dissipation is impaired causing premature wear
Solution Approach 1:
The housing is designed as a two-part structure with a first housing part and a second housing part that can be separated from each other. This segmentation allows the sealing elements to be installed and serviced independently while maintaining protection when assembled. The separation also creates thermal pathways that improve heat dissipation compared to a fully encapsulated design.
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
This design maintains excellent leakage behavior and noise performance, with leakage less than 3 g/100 h and suitable for use in automotive applications from -30°C to 125°C, while providing effective vibration damping and reliable sealing without premature wear.
Implementation Method 1
an elastomeric element (7) which bears with a radially inner area on the sealing lip (4) under radial force
Implementation Method 2
the sealing lip (4) lying with its sealing edge (22) on the outside (13) of the barrel sleeve (1) under radial prestress
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The shaft seal has a sealing element made from poluflurocarbon, particularly made from polytetrafluoroethylene, where the sealing element is provided with a sealing lip which is fitted at a surface (27) to be sealed under radial force. The sealing lip is loaded in the direction of the surface to be sealed by an elastomer element. The sealing element is fitted at the side of the elastomeric element. The elastometic element is arranged between a housing portion and the sealing element.