Roller Chain Inner-Link Structure for Misalignment and Wear

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Solution Overview

Problem

Existing chain transmission systems face issues with deformation, reduced service life, and misalignment tolerance due to the sliding contact between pins and bushings, leading to increased friction wear and machining complexities in bushless chains.

Innovation Solution

A chain design with a position restricting part between inner plates to prevent inward movement, allowing bushings to be rotatably inserted without being pressed through, which disperses sliding contact points and enhances wear resistance and misalignment tolerance by adjusting clearances between pins, bushings, and inner plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If bushings are pressed through and fixed to inner plates, then the chain structure is stabilized, but deformation of inner plates and distortion of bushings occurs, accelerating friction wear and shortening service life

Engineering Contradiction:
Improvechain structure stabilityVSAvoidservice life
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of moving object

Solution Approach 1:

The invention removes the bushings from the chain structure, extracting the problematic component that causes deformation and distortion. Instead of using traditional bushings pressed through inner plates, the patent employs a bushless design where pins directly engage with inner plates through precisely formed pin holes, eliminating the source of structural deformation and bushing distortion that accelerates wear.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the geometric parameters of the pin holes in inner plates through precise machining or forming processes. By optimizing the size, shape, and position of pin holes, the design achieves stable chain structure without requiring pressed bushings, thereby preventing both inner plate deformation and bushing distortion while maintaining structural stability throughout the service life.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If clearance between pins and bushings is increased to improve widthwise bendability, then misalignment tolerance improves, but friction wear accelerates due to varying pressure on sliding parts

Engineering Contradiction:
Improvemisalignment toleranceVSAvoidfriction wear
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces the sliding contact mechanical system between pins and bushings with a rolling contact system. By introducing rollers that rotate on the pins, the design transforms the friction-dominated sliding interface into a rolling interface, significantly reducing friction wear while maintaining the necessary clearance for misalignment tolerance and widthwise bendability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention introduces rollers as intermediary elements between the pins and inner plates. These rollers mediate the interaction by providing a rolling contact surface that reduces direct sliding friction between pins and inner plate surfaces, thereby decreasing friction wear while still allowing sufficient clearance for adaptability to misalignment and widthwise bending.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If bushless chain design is used to eliminate pressed components, then deformation of inner plates is reduced, but machining precision requirements increase to ensure proper clearance and wear resistance

Engineering Contradiction:
Improveinner plate strengthVSAvoidpin hole precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The invention optimizes the parameters of pin holes in inner plates through precise control of size, shape, and position during manufacturing. By carefully specifying and controlling these geometric parameters, the design achieves the necessary strength and wear resistance without pressed bushings, while the precision requirements are managed through standardized machining processes and quality control measures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies local quality enhancement to the pin hole regions in inner plates. Through localized precision machining or forming processes, the pin holes are created with high geometric accuracy and surface quality specifically where needed, while the rest of the inner plate can be manufactured with standard precision. This localized approach ensures proper clearance and wear resistance without requiring excessive precision throughout the entire component.

Inventive Principle:
Principle #3Local quality

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 solution increases the chain's strength, durability, and service life while reducing production costs and complexity, allowing for larger misalignment tolerance and improved wear resistance by minimizing deformation and internal distortion.

Implementation Method 1

the sliding contact between the pins 215 and the bushings 225

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

accelerate friction wear caused by the sliding contact between the pins 215 and the bushings 225

Methodology Applied
Scientific EffectWear: Wear

Implementation Method 3

the rollers 230 of the chain 200 passed around a sprocket make contact with the sprocket teeth

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4257843B1chain
Publication Date: 2024.07.03 TSUBAKIMOTO CHAIN CO
  • EP4257843B1 patent drawingFigure 1A~1B
  • EP4257843B1 patent drawingFigure 2A~2B
  • EP4257843B1 patent drawingFigure 3A~3B

AI summary

An object of the present invention is to provide a chain that is easy to assemble, has a longer life and smaller size, and allows larger tolerance for misalignment. The object is achieved by a chain including a plurality of outer links each having a pair of outer plates and pins, and a plurality of inner links each having a pair of inner plates and bushings, alternately and pivotably coupled together in the longitudinal direction of the chain by the pins rotatably inserted into the bushings, with a position restricting part positioned between each pair of the inner plates to restrict inward movement of each pair of inner plates in the chain width direction. The bushings are rotatably inserted in respective bushing holes of each pair of inner plates.