Gear Grinding Control for Precise End Relief Machining

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Solution Overview

Problem

Existing gear manufacturing methods face challenges in forming large end reliefs without increasing manufacturing costs and reducing efficiency due to interference issues with threaded grinding wheels, leading to inaccurate tooth surface shaping and potential damage from increased surface pressure.

Innovation Solution

A gear manufacturing apparatus and method that adjusts the relative position of the grinding tool using specific machining control, setting a different machining reference position for end regions to prevent excess machining and ensure accurate formation of end reliefs, using a single large-diameter tool to maintain efficiency and reduce costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a small-diameter tool is used to machine large end reliefs, then machining precision is improved, but tool life decreases and manufacturing cost increases

Engineering Contradiction:
Improveend relief formation precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the machining reference position parameter from the tool center to a position on the outer edge line of the tool in the X-axis-orthogonal cross section. This parameter change allows the use of a large-diameter tool while achieving the same end relief formation precision that would otherwise require a small-diameter tool, thereby reducing tool cost and extending tool life.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a small-diameter tool is used to machine large end reliefs, then machining precision is improved, but productivity decreases due to frequent tool changes

Engineering Contradiction:
Improveend relief formation precisionVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

By changing the machining reference position parameter to a position on the outer edge line of the tool, the patent enables the use of a large-diameter tool with longer life. This eliminates the need for frequent tool changes, thereby maintaining high productivity while achieving precise end relief formation.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the distance between tool center and gear workpiece center is increased, then excess machining at end portions is reduced, but the locus of tool center becomes more curved requiring higher performance apparatus

Engineering Contradiction:
Improvetooth surface shape accuracyVSAvoidapparatus performance requirement
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the reference position from the tool center to a position on the outer edge line of the tool. This parameter change allows for a more reasonable tool path with smaller curvature radius, reducing the performance requirements of the apparatus while still preventing excess machining at the end portions and maintaining tooth surface shape accuracy.

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

Enhances machining accuracy and prevents excess grinding, allowing for precise end relief formation without the need for frequent tool changes, thus maintaining manufacturing efficiency and reducing costs while ensuring gear quality.

Implementation Method 1

Grinding of a gear is performed by rotating a gear workpiece and a grinding tool in mesh with each other

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP4101568B1Gear manufacturing apparatus and gear manufacturing method
Publication Date: 2025.08.27 JTEKT CORP
  • EP4101568B1 patent drawingFigure 1~2
  • EP4101568B1 patent drawingFigure 3~5
  • EP4101568B1 patent drawingFigure 6~7

AI summary

A gear manufacturing apparatus for machining a gear workpiece (9) wherein, when at least one of end regions in a tooth trace direction of each tooth of the workpiece (9) is machined, a control device (7) executes a specific machining control for adjusting a relative position of a tool (8) to the workpiece (9) based on information about the relative position computed by setting, as a machining reference position, a position of the tool (8) on an outer edge line in an X-axis-orthogonal cross section different from a normal machining point such that a distance between a center of the tool (8) and a center of the gear workpiece (9) in the X-axis-orthogonal cross section when the at least one of the end regions is machined is larger than when the at least one of the end regions is machined by setting the normal machining point as the machining reference position.