Eccentric Gear Tooth Layout for Low-Backlash Torque Reversal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional gear drive systems experience noise due to backlash between gears, especially when alternating loads and torque changes direction, which affects the efficiency and longevity of the system.

Innovation Solution

A gear drive system with a second gear having distinct peripheral portions with varying gear tooth spacings and resilience, allowing for reduced or zero backlash at specific portions to minimize noise and structural stress, while maintaining typical backlash elsewhere to prevent overheating and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If backlash is provided between gears to reduce overheating or damage, then gear protection is improved, but noise increases due to alternating loads and torque changes

Engineering Contradiction:
Improvegear protectionVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The second gear is designed with non-uniform tooth spacing where specific portions have reduced or zero backlash while other portions maintain typical backlash. This local differentiation allows the gear to minimize noise at critical positions while preserving protective backlash elsewhere, resolving the contradiction between noise reduction and gear protection

Inventive Principle:
Principle #3Local quality

2Reliability

If uniform backlash is provided between gears, then gear protection is maintained, but noise is generated during torque reversals and alternating loads

Engineering Contradiction:
Improvegear protectionVSAvoidquiet operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Different portions of the second gear's periphery are designed with different tooth spacing characteristics. Specifically, portions corresponding to torque reversal zones have reduced backlash for quiet operation, while other portions maintain standard backlash for protection, allowing the system to achieve both quiet operation and gear protection simultaneously

Inventive Principle:
Principle #3Local quality

3Object-generated harmful factors

If backlash is reduced or eliminated at specific portions, then noise is minimized, but gear tooth spacing becomes non-uniform

Engineering Contradiction:
ImprovenoiseVSAvoidgear tooth spacing uniformity
Core Design Contradiction:
Object-generated harmful factorsVSShape

Solution Approach 1:

The gear tooth spacing is intentionally made non-uniform with specific portions having reduced spacing (zero or minimal backlash) while other portions maintain standard spacing. This localized variation in tooth spacing allows the gear to minimize noise during critical operations while preserving adequate backlash in other zones for protection and lubrication

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 system reduces noise and operational stress, enabling quieter operation and extended gear life by minimizing backlash during torque reversals and maintaining effective torque transmission.

Implementation Method 1

The first peripheral portion and/or the second peripheral portion are more resilient relative portions other than the first peripheral portion and/or the second peripheral portion, resulting in a first backlash between the first set of gear teeth and the teeth of the first gear, and a second backlash between the second set of gear teeth and the teeth of the first gear.

Methodology Applied
Scientific EffectResilience: Elasticity

Data Source

PatentEP3673188B1Eccentric gear drive with reduced backlash
Publication Date: 2022.09.28 ECOLAB USA INC
  • EP3673188B1 patent drawingFigure 1~2
  • EP3673188B1 patent drawingFigure 3~4
  • EP3673188B1 patent drawingFigure 5~6

AI summary

A gear drive system is provided having a first gear and a second gear. The second gear has a first peripheral portion and a second peripheral portion. A first set of gear teeth can be defined peripherally over the first peripheral portion and/or the second peripheral portion. The first peripheral portion and/or the second peripheral portion can be more resilient, resulting in a first backlash between the first set of gear teeth and the teeth of the first gear, less than a second backlash between the second set of gear teeth and the teeth of the first gear. Each gear tooth of the second gear can have a gear tooth spacing between adjacent gear teeth. The gear tooth spacing over the first peripheral portion and/or the second peripheral portion can be less than the gear tooth spacing at portions other than the first peripheral portion and/or the second peripheral portion.