Electronic Decoupling Hub for Rear Suspension Chain Growth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rear suspension systems in bicycles cause chain growth, leading to inefficiencies and detrimental feedback to the rider due to changes in chain stay length, which existing technologies fail to adequately address, affecting suspension performance and traction.
Innovation Solution
An electronic automatically decoupling hub assembly that selectively engages and disengages the cage assembly from the P-Knuckle assembly using a friction clutch, allowing for frictionless movement during chain growth and re-engaging to maintain chain tension, thereby reducing pedal feedback and maintaining traction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If rear suspension articulation is allowed to absorb terrain energy, then rider comfort and terrain traversal capability are improved, but chain stay length changes causing chain growth and detrimental feedback to the rider
Solution Approach 1:
The system segments the drivetrain connection by introducing a decoupling mechanism that separates the rear wheel sprocket from the chain. The freely rotating rear sprocket allows the chain to maintain tension while the rear suspension articulates independently, eliminating the transmission of chain growth feedback to the rider through the drivetrain.
Solution Approach 2:
The freely rotating rear sprocket acts as an intermediary element between the chain and the rear wheel. This mediator allows the chain to follow the changing chain stay length without transmitting forces to the drivetrain, thereby absorbing the chain growth effect and preventing it from feeding back to the rider.
2Adaptability or versatility
If the distance between center chain sprocket and rear wheel sprocket changes during suspension articulation, then rear suspension can adapt to terrain, but chain tightness varies causing inefficiencies
Solution Approach 1:
The system introduces dynamic behavior to the rear sprocket, allowing it to rotate freely and independently of the chain tension changes. This dynamic adaptation enables the drivetrain to maintain efficiency throughout the full range of suspension articulation, as the sprocket can accommodate varying chain tightness without causing energy loss or feedback.
3Productivity
If a rigid rear frame is used, then drivetrain efficiency is maintained, but rider comfort and terrain traversal capability are reduced
Solution Approach 1:
The system segments the connection between the drivetrain and the rear suspension by making the rear sprocket independently rotatable. This segmentation allows the rigid drivetrain components to maintain efficiency while the separated rear sprocket accommodates suspension movement, effectively decoupling the benefits of rigid and compliant designs.
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 reduces suspension-induced chain growth inefficiencies, improving pedal feedback and rear wheel traction by allowing the rear wheel to maintain consistent rotation with the terrain, enhancing the overall riding experience.
Implementation Method 1
selectively engages and disengages the cage assembly from the P-Knuckle assembly using a friction clutch, allowing for frictionless movement during chain growth
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An electronic automatically decoupling hub assembly (1000) is disclosed herein. The assembly has an axle (15) and a hub shell (1005) rotationally positioned about the axle. A controller (1010) provides automatic activation/deactivation signals to an inductor (1015). The assembly has a bearing (1025) rotationally positioned about the axle and a rachet ring (1020), having a plurality of teeth, rotationally positioned about the bearing. One or more pawls (1030) are provided to engage with at least some of the teeth of the ratchet ring and a seal (1035) is used to contain the pawls within the assembly. A cassette body assembly (1040) is coupled with the rachet ring and an end cap (1045) is used to prevent a contaminant from entering into the decoupling hub assembly.