Dual Gear Train Transmission With Axial Clamping for Zero Backlash

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Solution Overview

Problem

Existing gearboxes and actuators suffer from backlash, which affects their performance characteristics and precision in mechanical adjustments.

Innovation Solution

A dual gear train system is introduced, with a clamping device that applies axial force to reduce or eliminate backlash, allowing for parallel transmission of forces and torques, and a position encoder system using an absolute encoder to enhance precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single gear train is used, then the device complexity is low, but backlash occurs which reduces measurement precision and manufacturing precision

Engineering Contradiction:
Improvebacklash eliminationVSAvoidgear train structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines two gear trains in parallel between the same input and output shafts, creating a redundant transmission path. This merging of transmission paths allows the system to eliminate backlash through the interaction between the two gear trains while maintaining the same overall gear ratio, directly resolving the contradiction between precision improvement and complexity increase.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a movable gear element that can shift axially between two positions, engaging alternately with two different gear trains. This dynamic switching mechanism allows the system to maintain zero backlash by ensuring that at least one gear train is always under preload, resolving the backlash-precision contradiction while managing complexity through controlled movement rather than static dual engagement.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If a clamping device is added to eliminate backlash, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:
Improvebacklash reductionVSAvoidclamping mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs spring elements that pre-load the gear trains before operation begins, creating a cushioning effect that maintains constant contact between gear teeth. This beforehand cushioning ensures that backlash is eliminated from the start of operation, improving manufacturing precision while the spring mechanism adds minimal complexity compared to active clamping devices.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The movable gear element automatically shifts positions based on the direction of torque application, engaging the appropriate gear train that is pre-loaded in that direction. This self-service mechanism eliminates the need for external actuators or complex control systems to manage the clamping, as the system self-regulates to maintain zero backlash through its own operational dynamics.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If an absolute encoder is used for position control, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improveposition control accuracyVSAvoidencoder system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical end-stop based position control with an absolute encoder system that provides digital position information. This substitution eliminates the need for mechanical reference points and complex mechanical feedback mechanisms, improving measurement precision while the electronic encoder system manages complexity through non-contact sensing and digital signal processing.

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

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 dual gear train system reduces backlash, improving the operating characteristics and precision of mechanical adjustments, enabling accurate position control without mechanical end stops.

Implementation Method 1

the clamping device engages with a spring-loaded ball

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4123196B1Transmission and actuator
Publication Date: 2026.01.28 AUMA RIESTER GMBH & CO KG
  • EP4123196B1 patent drawingFigure 1~2
  • EP4123196B1 patent drawingFigure 3~4
  • EP4123196B1 patent drawingFigure 5~6

AI summary

In a transmission (5), it is proposed to form two parallel and separate gear trains (10, 12) between an input gear section (6) and an output gear section (8). (Fig. 2)