Unitized Seal Assembly with Axial Positioner for Lower Friction
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Solution Overview
Problem
Existing unitized radial lip seal assemblies face challenges in maintaining desired axial spacing and reducing frictional forces during rotation, often requiring complex and costly tooling changes for installation and modifications.
Innovation Solution
The introduction of an annular positioner coupled with the inner case, which engages the axial end of the bearing inner ring to locate the inner case at a desired position, eliminating the need for a rigid bumper and reducing frictional forces by allowing the seal assembly to be formed without a bumper or with a bumper spaced axially from the inner case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a rigid bumper is used to maintain axial spacing between inner and outer cases, then the desired axial spacing is maintained, but frictional forces increase during rotation
Solution Approach 1:
The patent removes the rigid bumper component from the seal assembly. Instead of using a bumper to maintain axial spacing, the design relies on the axial positioning of the seal lip relative to the inner case, allowing the outer case to rotate with minimal friction while the seal maintains its required spacing through the seal lip geometry and support from the inner case.
2Ease of operation
If a bumper is used to enable axial installation force transfer, then the seal assembly can be installed on the shaft, but the bumper adds device complexity
Solution Approach 1:
The bumper component is completely removed from the assembly. The installation process is simplified by applying axial force directly to the outer case, which then positions both the outer case and inner case axially relative to each other and to the shaft, eliminating the need for a separate bumper component and reducing overall assembly complexity.
3Stability of the object's composition
If the radial section of the inner case radially overlaps the outer case radial section, then structural integration is improved, but the installation tool engagement becomes more difficult
Solution Approach 1:
The design implements localized radial overlap between the inner and outer case radial sections to provide structural stability and integration where needed, while maintaining clear axial engagement surfaces on the outer case that allow installation tools to easily engage and apply axial force during installation. This creates different functional zones on different parts of the assembly.
Data Source
AI summary
A seal assembly is for sealing a bearing disposed between an inner shaft and an outer hub and includes an annular inner case having an axial section disposable about the shaft shoulder and a radial section extending radially outwardly from the axial section. An annular outer case is disposed about the inner case, has an axial section coupleable with the hub and a radial section extending radially inwardly from the outer case axial section and spaced axially from the inner case radial section. An elastomeric seal member is attached to the outer case radial section and has a sealing lip sealingly engaged with the axial section of the inner case. An annular positioner is coupled with the inner case and has a radial section engageable with the axial end of the bearing inner ring so as to locate the inner case at a desired position along the central axis.