Bicycle Joint Bearing Dust Cover With Impeller Dirt Deflection
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Solution Overview
Problem
Bicycle bearings in rotating joint assemblies, particularly in off-road cycling, are prone to wear and tear due to dirt ingress, and existing solutions like fully sealed bearings increase friction, while other designs fail to effectively prevent dirt ingress.
Innovation Solution
A rotating bicycle joint assembly with a dust cover extending radially beyond the bearing and an impeller at its outer periphery, deflecting dirt away during rotation, combined with a non-contact seal between the inner and outer rings to reduce friction and protect the bearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fully sealed bearings are used, then dirt ingress is prevented, but friction increases
Solution Approach 1:
The bearing protection system is divided into two functional segments: a dust cover that provides sealing without contact, and a non-contact seal within the bearing that prevents dirt ingress without increasing friction. This segmentation allows each component to perform its specific function optimally without the drawbacks of fully sealed bearings.
Solution Approach 2:
A dust cover is introduced as an intermediary component between the external environment and the bearing. The dust cover extends radially past the bearing outer periphery and is fixed to the inner part of the bearing, creating a protective barrier that prevents dirt ingress while allowing the bearing to operate with low friction through non-contact sealing.
2Reliability
If a dust cover is positioned around the bearing, then some dirt protection is provided, but gaps allow dirt ingress
Solution Approach 1:
The dust cover is designed to extend radially past the outer periphery of the bearing before dirt can reach the bearing through gaps. This preliminary positioning creates a first line of defense that intercepts dirt particles before they can penetrate into the bearing area, effectively preventing dirt ingress through the gaps between the dust cover and bearing.
3Reliability
If the dust cover extends radially past the bearing, then better sealing is achieved, but contact may increase friction
Solution Approach 1:
The sealing function is extracted from the dust cover itself and transferred to a dedicated non-contact seal within the bearing. The dust cover is designed to extend radially past the bearing outer periphery to provide structural support and positioning, while the non-contact seal performs the actual sealing function without contact, thereby eliminating the friction problem that would arise from contact between the dust cover and bearing outer periphery.
Solution Approach 2:
The mechanical contact-based sealing system is replaced with a non-contact sealing system. Instead of relying on physical contact between the dust cover and bearing to prevent dirt ingress, a non-contact seal is used that creates a sealing effect through pressure differential and flow control without mechanical contact, thereby eliminating friction while maintaining sealing effectiveness.
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 effectively prevents dirt ingress, reduces friction, and maintains bearing stability and longevity by deflecting dirt and mud away from the bearing, ensuring low internal friction and a tight seal.
Implementation Method 1
the impeller deflects dirt away from said rotating joint part when the rotating joint part is rotated
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
Disclosed is a rotating bicycle joint assembly (22) comprising a rotating joint part (23), a fixed joint part (24), and a bearing located between the rotating joint part and the fixed joint part with an outer part of the bearing fixed in relation to one of the rotating joint part and the fixed j oint part, and wherein an inner part of the bearing is fixed in relation to the other of the rotating joint part and the fixed joint part. The rotating bicycle joint assembly also comprises a dust cover (6) having an outer cover diameter being bigger than an outer bearing diameter of the bearing, so that an outer periphery of the dust cover is extending radially past the outer part. Furthermore, the rotating bicycle joint assembly comprises an impeller (9) arranged at the outer periphery of the dust cover, wherein the impeller is fixed in relation to the rotating joint part and wherein the dust cover is fixed in relation to the inner part of the bearing. Furthermore, a method for preventing ingress of dirt in a bearing of a rotating bicycle joint assembly and use of a rotating bicycle joint assembly is disclosed.