Dual-Spring Tensioner Lever for Chain Vibration Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tensioner levers with torsion coil springs face limitations in tolerable load and responsiveness due to fixed support arms, leading to inadequate reaction forces during sudden chain behavior changes, such as at engine startup or high-frequency resonance, resulting in vibration and noise issues.
Innovation Solution
A tensioner lever design incorporating two pressing springs with different characteristics, where the second spring is positioned differently on the lever body, allowing for consistent reaction force generation across varying chain behaviors, with the first spring handling normal loads and the second spring engaging for excessive loads, enhancing responsiveness and maximum load capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single torsion coil spring is used with a fixed support arm, then the structure is simple, but the maximum tolerable load is limited and responsiveness to sudden chain behavior changes is insufficient
Solution Approach 1:
The single torsion coil spring is segmented into two separate pressing springs (first pressing spring and second pressing spring) with different characteristics. The first pressing spring handles normal operating loads while the second pressing spring engages during excessive loads, providing staged responsiveness. This segmentation allows each spring to be optimized for specific load ranges, improving overall reliability without excessive complexity.
Solution Approach 2:
The support arm is transformed from a fixed structure to a dynamic structure that can pivot relative to the lever body. This dynamic connection allows the pressing mechanism to adapt its geometry and force application point based on the chain's behavior, enabling better responsiveness to sudden load changes while maintaining structural integrity.
2Device complexity
If a single torsion coil spring is used, then the device complexity is low, but the maximum tolerable load is insufficient when the chain undergoes resonance or large movements
Solution Approach 1:
The pressing function is segmented across two springs with different characteristics. The first pressing spring provides baseline pressing force for normal operation, while the second pressing spring is configured to engage and provide additional force during excessive loads such as resonance or large chain movements. This segmentation enables the system to handle a wider range of loads effectively.
Solution Approach 2:
The two pressing springs are designed with different parameters (spring constants, preloads, engagement points) to create a progressive pressing force characteristic. This parameter differentiation allows the system to provide appropriate pressing force across varying load conditions, increasing the maximum tolerable load while maintaining responsiveness.
3Stability of the object's composition
If the support arm is fixed, then the structure is stable, but the reaction force cannot be exerted correctly during sudden chain behavior changes
Solution Approach 1:
The support arm is designed to pivot dynamically on the attachment surface while maintaining stable support. This dynamic capability allows the support arm to adjust its position and maintain optimal force transmission geometry during sudden chain behavior changes, ensuring correct reaction force exertion while preserving overall structural stability.
Solution Approach 2:
The pivot connection between the support arm and attachment surface acts as an intermediary element that allows controlled movement. This intermediary joint enables the support arm to adapt to chain behavior changes while maintaining stable support, mediating between the need for stability and the need for responsive force exertion.
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 dual-spring configuration ensures improved responsiveness and increased maximum load handling, effectively reducing chain vibration and noise by consistently applying correct reaction forces during fluctuating chain behaviors.
Implementation Method 1
a first pressing spring (120) and a second pressing spring (130)... capable of consistently exerting a correct reaction force to various fluctuations of tension
Data Source
AI summary
To provide a simple-structured tensioner lever capable of consistently exerting a correct reaction force to various fluctuations of tension accompanying varying chain behaviors, whereby vibration and noise when the chain runs can be reduced. The tensioner lever of the present invention includes a lever body having a shoe surface that slidably guides a chain; a first pressing spring configured to have a first pressing arm extending from one end of a first helical part, with a distal end portion contacting the lever body to form a first loading point, and a first support arm extending from the other end of the first helical part, with a distal end portion contacting and being supported by a first support part provided to an attachment surface to form a first support point; and a second pressing spring supported on the lever body at a different position from that of the first pressing spring.