Suspension Hub and Rear Derailleur Decoupling for Chain Tension
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Solution Overview
Problem
Rear suspension systems on bicycles cause chain tightness issues due to articulation, leading to detrimental suspension performance and rider feedback, as the distance between the center chain sprocket and rear wheel sprocket changes, affecting chain stay length and traction.
Innovation Solution
An electronic automatically decoupling hub assembly with a ratchet ring and pawls, controlled by a sensor and controller, selectively engages or disengages to manage chain tension based on terrain and rider input, allowing the hub to enter a freewheel state and reduce chain stay length-induced forces on the rear wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If rear suspension articulation is allowed to improve terrain traversal capability, then suspension performance is enhanced, but chain tightness changes causing detrimental feedback to rider
Solution Approach 1:
The drivetrain system is segmented into independent controllable components: the hub assembly with electromagnetic decoupling mechanism and the derailleur with friction engagement capability. This segmentation allows independent control of chain tension management separate from suspension articulation, enabling terrain traversal while preventing chain tightness changes from affecting rider feedback.
Solution Approach 2:
The electromagnetic inductor and friction-based derailleur act as intermediary mechanisms between the suspension system and the drivetrain. These intermediaries absorb and manage the chain tightness changes caused by suspension articulation, preventing the harmful effects from being transmitted to the rider through the pedals.
2Object-generated harmful factors
If chain tension is maintained rigidly to prevent pedal feedback, then rider feedback is reduced, but suspension performance deteriorates
Solution Approach 1:
The system transitions from rigid chain tension maintenance to dynamic, condition-based tension management. The electromagnetic inductor and friction derailleur enable the drivetrain to adapt its chain tension characteristics in real-time based on suspension articulation conditions, allowing suspension to perform optimally while preventing harmful pedal feedback only when necessary.
Solution Approach 2:
The system implements feedback control where sensors detect suspension articulation and chain tightness changes, and the controller automatically activates the electromagnetic inductor and friction derailleur mechanisms to manage chain tension accordingly. This closed-loop feedback ensures suspension performance is maintained while pedal feedback is reduced only when chain tightness changes occur.
3Stability of the object's composition
If electronic automatically decoupling mechanism is added to manage chain tension, then chain stay length stability is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical chain tensioning mechanisms with an electromagnetic decoupling system. The electromagnetic inductor provides automatic engagement and disengagement of the drivetrain components through magnetic fields, eliminating the need for complex mechanical linkages, springs, and adjusters while achieving superior chain stay length stability.
Solution Approach 2:
The electromagnetic decoupling hub assembly and friction derailleur system operate autonomously based on sensor input and controller logic. The system self-regulates chain tension by automatically engaging and disengaging the electromagnetic inductor and friction mechanisms without requiring manual intervention or complex mechanical adjustment mechanisms, simplifying the overall device architecture.
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 solution improves rear wheel traction and reduces pedal feedback by managing chain tension dynamically, maintaining optimal chain stay length and reducing suspension-induced inefficiencies, thereby enhancing the overall riding experience.
Implementation Method 1
an inductor comprising at least one pawl to selectively engage or disengage with the at least one tooth of the ratchet ring
Implementation Method 2
The sensor may be an accelerometer, an optical detection device, or an image capturing device
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A bicycle system comprising a suspension (38,34), a chain (19) and a disengageable derailleur assembly (17), the disengageable derailleur assembly comprising: a P-knuckle assembly (510) comprising a clutch plate (635); and a cage assembly (565) having a cage-assembly counterpart (650); wherein the clutch plate selectively and frictionally engages the cage-assembly counterpart based on manual or automatic inputs from the bicycle system: the disengaging occurring when performance is paramount to eliminate the inefficiencies caused by suspension induced chain growth; and the reengaging occurring as needed to ensure the chain stays in an appropriate location to properly propel the bicycle system.