Tension Reducing Sprockets for Multi-Resonance Chain Systems
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Solution Overview
Problem
Chain and sprocket systems in automotive engines experience undesirable noise and increased chain tensions due to resonance modes, leading to wear and potential failure, as conventional noise-reducing sprockets often concentrate tension forces, exacerbating these issues.
Innovation Solution
The use of two or more tension-reducing sprockets with varying root or pitch radii patterns oriented to cooperatively reduce maximum chain tensions at specific resonance modes without significantly increasing tensions at other modes, effectively canceling or minimizing tension excitations across multiple resonance frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional noise-reducing sprockets with varying root radii are used, then noise is reduced, but chain tension forces are concentrated and increased
Solution Approach 1:
The sprocket features non-uniform root radii distributed around its circumference, where different sections have different root radius values. This local variation in geometry allows the sprocket to reduce noise through controlled tension modulation while distributing the tension forces more evenly across the chain-sprocket engagement points, preventing concentration of forces at single locations.
Solution Approach 2:
The invention changes the root radius parameter along the circumference of the sprocket, creating a pattern of varying root radii rather than uniform radii. This parameter variation is designed to alter the tension profile during chain engagement, reducing noise-generating vibrations while maintaining acceptable tension levels through proper distribution of the radius variations.
2Force
If multiple tension-reducing sprockets with varying root radii are used, then maximum chain tensions at resonance modes are reduced, but device complexity increases
Solution Approach 1:
The solution divides the chain drive system into multiple sprocket units, each equipped with varying root radii patterns. By distributing tension-reducing functionality across multiple sprockets rather than relying on a single complex sprocket, the system achieves better resonance mode control while maintaining manageable complexity through modular repetition of the varying root radius design.
Solution Approach 2:
The varying root radii are arranged in periodic patterns around the sprocket circumference, creating repeating sequences of radius variations. This periodic structure allows the sprockets to systematically address resonance modes at specific frequencies while maintaining manufacturing simplicity through repetitive geometric patterns that can be efficiently produced.
Data Source
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AI summary
In chain and sprocket systems with at least two resonance modes, two or more tension reducing sprockets are oriented to cancel each other at a first resonance mode and have no effect to increase tensions at such first resonance mode. The tension reduction sprockets, however, are oriented with each other so that tensions will be reduced at a second resonance mode. Hence, two or more tension reducing sprockets are used to reduce tensions at a second resonance mode from sources outside the chain and sprocket system while minimizing tension increases at first resonance mode.