Silent Chain Sprocket Flange Seating for Noise and Wear Reduction
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Solution Overview
Problem
Chain drive mechanisms with varying tooth root radii cause rotation fluctuations and increased wear, leading to reduced power transmission efficiency and noise, as the silent chain sits on the sprocket, necessitating a solution to minimize these issues.
Innovation Solution
The introduction of circumferentially protruding flanges on the sprocket and seat portions on the chain allows the chain to sit without touching the sprocket teeth, maintaining a constant pitch radius and reducing wear by contacting at different points, thereby minimizing rotation fluctuations and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If tooth roots have different root circle radii to reduce noise, then noise is reduced, but pitch radius varies causing rotation fluctuations
Solution Approach 1:
The patent introduces flanges as intermediary elements that contact the chain at a different location than the teeth. The flanges serve as a mediator between the chain and sprocket, allowing the chain to sit on the flanges rather than the teeth, thereby decoupling the noise-reducing varying root circle radii from the pitch radius determination.
Solution Approach 2:
The patent shifts the contact point from the radial dimension (tooth roots) to the axial dimension (flanges). By making the flanges protrude axially from the sprocket, the chain contacts the flanges on the axial side rather than the teeth from the radial side, separating the functions of noise reduction and pitch radius stability.
2Power
If chain sits on teeth to transmit power, then power transmission is achieved, but wear progresses fast on tooth surfaces
Solution Approach 1:
The flanges act as intermediary contact surfaces that replace the teeth as the primary seating location for the chain. This intermediary element absorbs the wear that would otherwise occur on the tooth surfaces, protecting the critical power transmission interface.
Solution Approach 2:
The patent extracts the seating function from the teeth and relocates it to the flanges. By separating the seating function from the power transmission function (which remains handled by the teeth), the design allows the chain to sit on the flanges while still transmitting power through the tooth engagement.
3Force
If varying root circle radii are used to reduce maximum chain tension, then chain tension is reduced, but pitch radius variation causes rotation fluctuations
Solution Approach 1:
The flanges serve as a stabilizing intermediary that maintains constant pitch radius during chain seating. This allows the varying root circle radii to continue reducing maximum chain tension while the flanges prevent rotation fluctuations by providing a consistent seating reference point.
Data Source
AI summary
To provide a simple-structured chain drive mechanism that can reduce the noise generated when the chain sits on the sprocket, prevent deterioration of power transmission efficiency, and retard the progress of wear on the sprocket or chain. The chain drive mechanism includes a sprocket having a plurality of teeth, and a chain having a plurality of link plates and configured to be put around the sprocket. The sprocket includes a pair of flanges protruding circumferentially around the sprocket such as to sandwich the plurality of teeth from sides. The chain includes a pair of seat portions on both sides of the chain so that the flanges abut on the seat portions from a circumferential direction of the sprocket when the chain sits.