Eccentric Gear Tooth Spacing for Low-Backlash Torque Reversal

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Solution Overview

Problem

Conventional gear drive systems in reciprocating pumps experience noise due to backlash between gears, especially when the direction of rotation changes, leading to inefficient torque transmission and potential damage.

Innovation Solution

A gear drive system with a second gear having distinct peripheral portions with varying gear tooth spacing and resilience, allowing for reduced or zero backlash at specific engagement points, thereby minimizing noise and improving torque transmission efficiency.

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 during alternating loads and torques

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 spacing to minimize backlash during critical engagement zones, while other portions maintain larger spacing to prevent overheating and damage. This local differentiation allows the gear to exhibit different backlash characteristics in different angular positions, simultaneously achieving noise reduction during torque reversal and thermal protection during continuous operation.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If uniform gear tooth spacing is used, then manufacturing is simplified, but noise occurs during alternating loads and torque direction changes

Engineering Contradiction:
Improvegear manufacturingVSAvoidnoise during torque reversal
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The gear tooth spacing is made non-uniform with specific portions having reduced spacing angles compared to uniform gears. This local modification targets the engagement zones where torque direction changes occur, allowing the gear to maintain better tooth contact during reversal without requiring complete redesign of the entire gear geometry, thus balancing manufacturing feasibility with noise reduction.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The gear tooth spacing parameter is varied locally rather than maintained uniformly throughout. By changing the spacing parameter in specific angular portions of the gear, the invention optimizes backlash characteristics during torque reversal events while maintaining manufacturability through localized rather than global parameter changes.

Inventive Principle:
Principle #35Parameter changes

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 reduces noise and enhances operational efficiency by minimizing backlash, particularly during changes in motor torque and plunger direction, while also reducing the risk of overheating and structural damage.

Implementation Method 1

The first peripheral portion and/or the second peripheral portion can be 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

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4141290A1Eccentric gear drive with reduced backlash
Publication Date: 2023.03.01 ECOLAB USA INC
  • EP4141290A1 patent drawingFigure 1~2
  • EP4141290A1 patent drawingFigure 3~4
  • EP4141290A1 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.