Spring-Loaded Idler Gear Assembly for Precise Backlash Adjustment

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Solution Overview

Problem

The adjustment of backlash in gear transmissions with multiple meshing gears is time-consuming and costly due to the need for external actuators to apply precise forces, which can also risk damaging coatings on the gears.

Innovation Solution

A pre-assembled gear wheel-bearing element-spring element unit is used, where the spring element is designed as a sleeve or hyperboloid to simplify assembly and centering, allowing the third gear to be pressed against other gears without external force, and can be connected to a nut for precise positioning, enabling flexible contact pressure adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If external actuators are used to press the third gear against other gears for backlash adjustment, then precise force application is achieved, but assembly time increases and costs increase

Engineering Contradiction:
Improvebacklash adjustment precisionVSAvoidassembly time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The spring element is pre-installed on the bearing pin before the third gear is mounted. This preliminary action ensures that the force application mechanism is already in place, eliminating the need for external actuators during assembly and reducing assembly time while maintaining precise backlash adjustment capability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The spring element automatically applies the necessary force to press the third gear against the other gears through its elastic recovery. This self-service mechanism eliminates the need for external actuators, reducing both assembly time and complexity while maintaining precise backlash control

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If external actuators are used to apply precise force for backlash adjustment, then tooth flank play can be adjusted, but the risk of damaging coatings on gears increases

Engineering Contradiction:
Improvetooth flank play adjustmentVSAvoidcoating damage risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The spring element is pre-installed on the bearing pin before the third gear is mounted. This allows the gear to be pushed on without load, preventing coating damage, while the spring element subsequently applies the necessary force for precise backlash adjustment without requiring external actuators that could cause damage

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The spring element automatically applies the necessary force to press the third gear against the other gears through its elastic recovery. This self-service mechanism applies force gradually and controllably, eliminating the risk of sudden force application that could damage gear coatings while achieving precise tooth flank play adjustment

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If a bearing bolt is fixed rigidly in the housing, then assembly is simple, but backlash adjustment becomes difficult

Engineering Contradiction:
Improveassembly simplicityVSAvoidbacklash adjustment capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The force application function is separated from the bearing bolt by introducing a spring element. The bearing bolt provides simple rigid support for easy assembly, while the spring element provides the adjustable force necessary for backlash adjustment, dividing the functions to resolve the contradiction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring element introduces dynamic force application capability to the otherwise static bearing bolt assembly. The spring can be pre-compressed to different degrees, allowing adjustable backlash while maintaining the simple rigid mounting structure of the bearing bolt in the housing

Inventive Principle:
Principle #15Dynamics

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 solution simplifies the adjustment of tooth flank play, reduces assembly time and costs, and prevents damage to coatings by allowing the third gear to mesh unloaded, improving precision and noise behavior in gear transmissions.

Implementation Method 1

With the help of the spring element, the third gear is pressed against the other two gears

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP3765769B1Gear transmission
Publication Date: 2022.03.09 HIGH TECH COATINGS
  • EP3765769B1 patent drawingFigure 1~2
  • EP3765769B1 patent drawingFigure 3

AI summary

The invention relates to a gear transmission (1) comprising a first gear wheel (2) having a first tooth system (5), a second gear wheel (3) having a second tooth system (7) and a third gear wheel (4) having a third tooth system (9), wherein the third gear wheel (4) is arranged between the first and the second gear wheel (2, 3) and the third tooth system (9) intermeshingly engages with the first and the second tooth system (5, 7), wherein furthermore the third gear wheel (4) is rotatably mounted on a bearing pin (11) by means of a bearing element (12), and the bearing pin (11) extends through an opening (16) in a wall (17). The bearing pin (11) is permanently radially fixed in the opening (16) of the wall (17). A spring element (21) is arranged between the bearing pin (11) and the bearing element (12).