Cycle Wheel Suspension With Unequal Gas Piston Areas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Telescopic front suspension forks for two-wheeled vehicles suffer from high stiction, reduced mechanical trail during suspension compression, inadequate leverage ratio, and increased instability due to their design, which affects handling and stability, especially during braking and cornering.
Innovation Solution
A suspension assembly with a steering fork featuring a first arm with a shock absorber and a second arm with a spring unit, both equipped with gas springs, where the gas piston areas are unequal, providing a multi-bar linkage configuration that balances force outputs and adjusts leverage ratios to enhance stability and reduce stiction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If telescopic fork stanchions are made larger to support fore/aft loads, then load-bearing capacity is improved, but stiction increases and compliance decreases
Solution Approach 1:
The suspension system is segmented into multiple independent components: a first suspension device on one fork leg and a second suspension device on the other fork leg. Each device independently handles suspension loads, preventing the need for oversized stanchions that would generate excessive stiction. The segmentation allows each component to be optimized for its specific function rather than requiring all components to handle maximum loads.
Solution Approach 2:
The patent inverts the traditional telescopic fork architecture by using a linkage-based suspension system where the fork legs do not directly compress. Instead, the suspension linkage absorbs compression forces through a four-bar mechanism, allowing the fork stanchions to remain smaller and generate less stiction while maintaining load-bearing capacity.
2Strength
If telescopic fork compression is increased to improve shock absorption, then bump absorption is improved, but mechanical trail reduces and stability decreases
Solution Approach 1:
The linkage suspension system dynamically maintains mechanical trail throughout the suspension compression range. As the suspension compresses, the four-bar linkage geometry changes to preserve the mechanical trail distance between the steering axis and wheel contact point. This dynamic adjustment ensures stability is maintained during compression while still allowing effective shock absorption.
3Stability of the object's composition
If fork stanchion angle is made slacker to improve angle of attack stability, then angle of attack stability is improved, but bushing load increases and stiction increases
Solution Approach 1:
The suspension system separates the functions of angle management and shock absorption. The linkage mechanism handles shock absorption while the fork stanchions maintain a steeper angle for reduced bushing load and stiction. This segmentation allows optimization of each component for its primary function without compromise.
4Device complexity
If telescopic fork is designed with direct spring attachment to wheel, then leverage ratio is simplified, but leverage ratio becomes constant 1:1 and adaptability decreases
Solution Approach 1:
The four-bar linkage suspension creates a dynamic leverage ratio that varies throughout the suspension compression range. As the linkage geometry changes during compression, the mechanical advantage between wheel movement and spring compression changes, providing adaptive leverage rather than a fixed 1:1 ratio. This allows the system to optimize force multiplication at different compression levels.
Data Source
AI summary
A suspension assembly for a cycle having improved stability includes a steering fork having a first arm and a second arm, each of the first arm and the second arm having a fixed pivot and a shock pivot, the space between the first arm and the second arm defining a wheel opening. A shock link has a shock link fixed pivot and a shock link floating pivot. A shock absorber has a shock gas spring comprising a shock spring body a shock gas piston having a first gas piston area, a spring unit has a spring gas spring comprising a spring body and a spring gas piston having a second gas piston area. The first gas piston area is not equal to the second gas piston area.