Silent Chain Locker Pin Gap for Pitch Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silent chain transmission devices experience unstable chain behavior, leading to increased string vibration sound and meshing noise due to pitch mismatch between rolling points and sprocket pitch, especially under varying load conditions, which can result in tooth skipping.
Innovation Solution
The silent chain and transmission device are designed with locker pins and pin holes that allow for adjustable pitch between rolling points, ensuring the pitch is equal to or longer than the sprocket pitch, even under low load conditions, and include features like gaps between seat surfaces and pin surfaces to facilitate movement and maintain stable winding around the sprocket.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pitch between rolling points is set shorter than the sprocket pitch to account for elastic and wear elongation, then winding improvement is expected after elongation occurs, but chain behavior becomes unstable in the initial and low load states causing increased vibration noise and meshing noise
Solution Approach 1:
The patent changes the pitch parameter between rolling points to be equal to or slightly longer than the sprocket pitch in the initial state, reversing the conventional approach. This parameter adjustment ensures stable chain behavior and reduced noise in low load conditions while maintaining acceptable winding performance after elongation occurs through the gap mechanism between locker pins and pin holes
2Object-generated harmful factors
If the pitch between rolling points is set equal to or longer than the sprocket pitch in low load state, then chain behavior stability and noise reduction are achieved, but under high load the elastic elongation causes pitch decrease and increases risk of tooth skipping
Solution Approach 1:
The patent introduces dynamic adjustability through the gap between the back surface of locker pins and seat surfaces of pin holes. This gap allows the pitch between rolling points to dynamically adjust: maintaining equality with or exceeding sprocket pitch in low load states for noise reduction, and accommodating elastic elongation-induced pitch decrease in high load states to prevent tooth skipping
Solution Approach 2:
The patent segments the pin connection system into multiple components (locker pins, pin holes with seat surfaces, and deliberate gaps) that can move relative to each other. This segmentation enables the pitch to be adjusted independently from the sprocket pitch, allowing optimization for different load conditions without compromising overall chain-sprocket engagement
3Reliability
If the pitch between rolling points is set equal to or shorter than the sprocket pitch in the guide row to improve winding after elongation, then similar problems occur as in the non-guide row with unstable chain behavior and increased noise
Solution Approach 1:
The patent applies the same pitch parameter change to the guide row as to the non-guide row, setting the pitch between rolling points equal to or slightly longer than the sprocket pitch. This unified approach ensures consistent chain behavior and noise reduction across both guide and non-guide rows in low load states
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 configuration stabilizes chain behavior, reduces string vibration and meshing noise, and prevents tooth skipping by maintaining optimal winding tension and alignment with the sprocket, even under high loads or wear elongation.
Implementation Method 1
the pin holes of the inner plates and the pair of locker pins are formed in such a size that a gap is formed between the seat surface of the inner plates and the back surface of the short pin in a state where the pair of locker pins are in contact with each other on the rolling surfaces
Data Source
AI summary
An object of the present invention is to provide a silent chain and a silent chain transmission device which stabilize chain behavior during chain travel to suppress an occurrence of tooth skipping and to reduce a string vibration sound and a meshing noise with simple configurations. In a silent chain 110, a pin hole 161 of an inner plate 160 and a pair of locker pins 170 are configured in such a size that a gap is formed between a seat surface 163 and a back surface of a short pin 172 in a state where the pair of locker pins 170 are in contact with each other on rolling surfaces 171a and172a.