Floating Shield Labyrinth Seal for Motorbike Wheel Hub
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Solution Overview
Problem
Existing sealing devices for motorbike wheel hubs are either too large in axial dimension, incompatible with most applications, or have reliability issues due to performance decay over time, especially when exposed to high-pressure water jets and frequent maintenance.
Innovation Solution
A sealing device with a plastic shield mounted in a floating manner within an annular chamber, creating a labyrinth seal that enhances protection and durability by centrifuging contaminants, while being easy to assemble and disassemble with a funnel-shaped radially inner end for reduced friction and axial play.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stiff reinforcing insert with additional crawling or non-crawling sealing lips is used, then sealing effectiveness is improved, but axial dimensions become large and incompatible with most applications
Solution Approach 1:
The patent applies the dynamics principle by making the intermediate portion of the shield movable relative to the reinforcing insert. The shield can move axially within the annular chamber, allowing it to adapt to radial and axial displacements of the pin. This dynamic configuration maintains effective sealing contact without requiring large axial dimensions, resolving the contradiction between sealing effectiveness and compact size.
Solution Approach 2:
The patent uses a flexible plastic shield as an intermediate sealing element. The shield's flexibility allows it to deform and maintain sealing contact under various operating conditions while occupying minimal axial space. This thin-film approach provides effective sealing without the bulk of traditional stiff sealing structures.
2Length of moving object
If additional sealing lips with particular geometries are used to reduce axial dimensions, then compactness is improved, but sealing performance decays over time and reliability decreases
Solution Approach 1:
The patent introduces an intermediate plastic shield as a mediator between the rotating wheel hub and the stationary pin. This shield creates a labyrinth seal that protects the main sealing lips from direct exposure to contaminants and high-pressure water jets. The intermediate shield absorbs the brunt of external attacks, preserving the longevity and performance stability of the primary sealing lips over time.
Solution Approach 2:
The labyrinth seal formed by the intermediate shield provides beforehand cushioning by deflecting and redirecting water jets and contaminants before they reach the main sealing lips. This protective barrier prevents direct impact and wear on the critical sealing surfaces, maintaining sealing performance stability throughout the service life.
3Reliability
If a complex sealing structure is used to improve reliability, then sealing effectiveness is improved, but ease of assembly and disassembly deteriorates
Solution Approach 1:
The patent segments the sealing device into distinct functional components: a reinforcing insert, a separate intermediate plastic shield, and sealing lips. The intermediate shield is designed as a separate element that can be independently installed and removed. This segmentation allows for simplified assembly and disassembly procedures while maintaining the reliability benefits of a multi-component sealing system.
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 solution provides a compact, high-efficiency, and reliable sealing mechanism that maintains performance over time, effectively protecting the wheel hub from contaminants and simplifying assembly and disassembly with minimized production costs.
Implementation Method 1
which, in use, creates a centrifugation of the external contaminants by effect of the rotation of the annular chamber together with the wheel
Data Source
AI summary
A sealing device including an annular reinforcing insert couplable with a wheel hub in use and an annular sealing element carried by the reinforcing insert and including at least one sealing lip cooperating with a spacer carried by a wheel support pin in use; the reinforcing insert delimits an annular chamber arranged directly adjacent to the annular sealing element in axial direction, and the device further includes a shield mounted in floating manner with radial and axial play in the annular chamber, including a first radial end, which extends to the lip and couples in forced manner with the spacer in use, and a second radial end, opposite to the first, which cooperates with the reinforcing insert and with the annular sealing element to create a labyrinth seal in the annular chamber interposed in use between the annular lip and an environment (E) external to the wheel hub.