Skiving Tool Transition Surface Geometry for Clean Tooth Tips

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Solution Overview

Problem

The existing skiving tools often produce an undesired interference contour on the tooth tips due to orthogonal transition surfaces between chip faces, leading to quality issues and the need for reworking, which is time-consuming and costly.

Innovation Solution

The skiving tool features transition surfaces where surface normals enclose an angle greater than 0° with adjacent chip faces, avoiding orthogonal orientation and thus eliminating the formation of interference contours, allowing direct machining of tooth tips without prior internal turning or subsequent reworking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If transition surfaces between chip faces are oriented orthogonally (as in prior art), then machining process is simple, but interference contours form on tooth tips reducing quality

Engineering Contradiction:
Improvetooth tip qualityVSAvoidtransition surface geometry
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the geometric parameter of the transition surface by defining it through surface normals that enclose a specific angle (greater than 0 degrees) with adjacent chip faces, rather than using orthogonal transition surfaces. This parameter change eliminates interference contours on tooth tips while maintaining manufacturability through controlled angular relationships in the cutting head geometry.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If orthogonal transition surfaces are used, then tool design is straightforward, but reworking is required increasing time and cost

Engineering Contradiction:
Improvegear production efficiencyVSAvoidreworking time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by designing the transition surfaces with correct angular orientation (surface normals enclosing greater than 0 degrees with chip faces) before the machining process begins. This preliminary geometric configuration prevents interference contour formation during tooth tip machining, eliminating the need for subsequent reworking operations and thereby increasing productivity.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If transition surfaces are angled relative to chip faces, then interference contours are eliminated, but manufacturing complexity increases

Engineering Contradiction:
Improvetooth tip surface qualityVSAvoidcutting head manufacturing
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent transforms the manufacturing challenge by changing the defining parameter of transition surfaces from orthogonal orientation to angular orientation (surface normals enclosing greater than 0 degrees with chip faces). This parameter change achieves superior tooth tip surface quality while the angular relationship provides a clear manufacturing guideline that balances precision requirements with manufacturability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3694670B1Skiving tool
Publication Date: 2022.10.19 HARTMETALL WERKZEUGFAB PAUL HORN
  • EP3694670B1 patent drawingFigure 1
  • EP3694670B1 patent drawingFigure 2~4
  • EP3694670B1 patent drawingFigure 5~6

AI summary

The invention relates to a skiving tool (10) having a shaft (12), which extends along a longitudinal axis (14) of the tool (10), and a cutting head (16), which is arranged on a face end of the shaft (12), wherein: the cutting head (16) has a plurality of circumferentially arranged teeth (18); each of said teeth (18) has, on a face end of the cutting head (16) facing away from the shaft (12), a planar cutting face (20), which is inclined relative to the longitudinal axis (14) at an angle not equal to 90°; a transition surface (22) is arranged between the cutting faces (20) of each pair of adjacent teeth (18), said transition surface also being arranged on the face end of the cutting head (16) and being directly adjacent to the cutting faces (20) of the two adjacent teeth (18); surface normals (23) at all points of the transition surface (22) each form an angle (β) greater than 0° with the cutting faces (20) of the two adjacent teeth (18).