Gear Tooth Root Contour Correction for Higher Load Capacity

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Solution Overview

Problem

Existing gear production methods fail to achieve a balance between high mechanical strength, reliability, and economic efficiency, particularly in producing toothing with enhanced tooth root load-bearing capacity.

Innovation Solution

A method for producing toothing that involves selecting starting and partial contours, applying a correction specification using an adjustable function parameter, and employing a combination of elliptical and involute shapes to increase tooth root load-bearing capacity, while maintaining ease of production and adaptability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional toothing geometries are used, then production is simple and economical, but tooth root load-bearing capacity is insufficient

Engineering Contradiction:
Improvetooth root load-bearing capacityVSAvoidtoothing geometry complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The tooth profile is divided into multiple sections: a first toothing section with involute geometry for the working flanks, and a second toothing section with modified geometry (including root relief and variable tooth thickness) for the root area. This segmentation allows optimization of each section independently - the involute section maintains simple manufacturing while the modified section enhances root strength without affecting the entire tooth geometry

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different geometric modifications locally to specific areas of the tooth. The tooth flanks retain standard involute geometry for rolling contact, while the root area receives localized modifications including root relief and variable tooth thickness. This local quality approach improves root load-bearing capacity without compromising the functional areas or requiring complete redesign of the entire toothing

Inventive Principle:
Principle #3Local quality

2Strength

If tooth root area is thickened to increase load capacity, then strength improves, but manufacturing complexity increases

Engineering Contradiction:
Improvetooth root load-bearing capacityVSAvoidtoothing production ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical tooth root geometries with a mathematically defined approach using equations that describe variable tooth thickness and root relief. Instead of relying on complex mechanical shaping processes, the tooth geometry is defined analytically through formulas that can be directly implemented in CNC programming and gear generation processes, simplifying manufacturing while achieving the desired root strength

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

Solution Approach 2:

The patent modifies key geometric parameters of the tooth root area, including variable tooth thickness (s(x)) and root relief depth (f(x)), as functions of the radial coordinate. By changing these parameters continuously according to mathematical relationships rather than using fixed discrete values, the design achieves optimized root strength while maintaining compatibility with standard manufacturing processes that can accommodate continuous parameter variations

Inventive Principle:
Principle #35Parameter changes

3Strength

If standard involute toothing is used, then manufacturing is easy, but tooth root strength is insufficient for high-load applications

Engineering Contradiction:
Improvetooth root load-bearing capacityVSAvoidtoothing geometry precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent replaces traditional mechanical tooth generation methods with a mathematically precise definition of tooth geometry using analytical equations. The variable tooth thickness and root relief are defined through formulas that can be directly translated into precise CNC toolpaths, ensuring high manufacturing precision while maintaining ease of production through standardized mathematical descriptions rather than complex mechanical tooling

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

Data Source

PatentEP3977216B1Production method for a cog, tool and machine component
Publication Date: 2022.12.28 FLENDER GMBH
  • EP3977216B1 patent drawingFigure 1
  • EP3977216B1 patent drawingFigure 2
  • EP3977216B1 patent drawingFigure 3

AI summary

The invention relates to a method (100) for producing teeth (10), comprising the following steps: In a first step (110), a root-side starting contour (20) and a tip-side partial contour (22) of a tooth (12) are selected. In a second step (120), an adjustment region (38) is selected for at least one part of the root-side starting contour (20). There is also a third step (130), in which a correction specification (35) is determined for the adjustment region (38). Moreover a fourth step (140) is carried out, in which the root-side starting contour (20) is changed on the basis of the correction specification (35) to form a root-side end contour (24). According to the invention, the correction specification (35) is determined on the basis of a correction function (30) that comprises at least one adjustable functional parameter (39). The invention also relates to a computer program product (80) for carrying out the method (100), a tool (50) which is manufactured on the basis of the method (100), and a machine component (60) in which a corresponding tool (50) is implemented.