Gear Skiving Infeed Control for Vibration-Stable Deep Tooth Cutting

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Solution Overview

Problem

The existing skiving methods for gearing result in vibrations and reduced machining quality and tool life due to abrupt changes in the effective cutting edge length during the process, especially with high meshing depths and large tooth modules.

Innovation Solution

The method involves changing the center distance and torsion angle step-by-step during machining, allowing for a gradual reduction in the effective cutting edge length, with alternating machining of tooth flanks and a pendulum-like infeed to minimize vibrations and extend tool life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the effective cutting edge length is increased to machine large tooth modules and deep tooth gaps, then the machining capability is improved, but vibrations occur leading to reduced machining quality and tool life

Engineering Contradiction:
Improvemachining capability for large tooth modulesVSAvoidtool life and machining quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by continuously varying the twist angle between the cutting tooth and workpiece during the skiving process. This dynamic adjustment of the twist angle prevents the effective cutting edge length from remaining constant, thereby avoiding the vibrations that occur with high meshing depths. The cutting process transitions from a static to a dynamic state where the twist angle is modulated to maintain optimal cutting conditions throughout the engagement of the cutting edge with the workpiece.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by systematically varying the twist angle as a controlling parameter during the skiving operation. By changing the twist angle from its initial value to a final value during the cutting process, the effective cutting edge length is dynamically adjusted. This parameter change approach allows the process to handle large tooth modules and deep tooth gaps while preventing the vibration-induced quality degradation and tool life reduction that would otherwise occur.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the center distance is changed to deepen tooth gaps between machining steps, then the tooth gap deepening is improved, but the effective cutting edge length changes abruptly causing vibrations

Engineering Contradiction:
Improvetooth gap depthVSAvoideffective cutting edge length stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by continuously varying the twist angle between the cutting tooth and workpiece during the skiving process. This dynamic adjustment of the twist angle prevents the effective cutting edge length from remaining constant, thereby avoiding the vibrations that occur with high meshing depths. The cutting process transitions from a static to a dynamic state where the twist angle is modulated to maintain optimal cutting conditions throughout the engagement of the cutting edge with the workpiece.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements periodic action through the systematic variation of the twist angle during the skiving process. The twist angle is continuously adjusted in a controlled manner, creating a periodic modulation of the effective cutting edge length. This periodic variation prevents abrupt changes in cutting conditions, thereby eliminating the vibrations that would otherwise be generated during the deepening of tooth gaps through center distance changes.

Inventive Principle:
Principle #19Periodic action

3Manufacturing precision

If the number of machining steps is increased to improve machining quality, then the processing precision is improved, but the process time is extended

Engineering Contradiction:
Improvegear machining qualityVSAvoidtotal machining time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies continuity of useful action by maintaining the cutting edge in continuous engagement with the workpiece throughout the skiving process. By dynamically adjusting the twist angle during the operation, the process achieves high machining quality in a single continuous pass rather than requiring multiple discrete machining steps. This continuous action eliminates the idle time between steps while preserving the quality benefits of multiple passes, thereby reducing total machining time.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3043945B1Skiving method and corresponding device
Publication Date: 2021.09.29 PROFILATOR
  • EP3043945B1 patent drawingFigure 1~2
  • EP3043945B1 patent drawingFigure 3
  • EP3043945B1 patent drawingFigure 4

AI summary

The invention relates to a method and a device for cutting teeth into workpiece wheels (6) by means of skiving using a skiving wheel (1) that has cutting teeth (3), said device having a workpiece spindle for receiving the workpiece wheel (6) and a tool spindle, wherein the tool spindle and the workpiece spindle are positioned relative to each other at a crossed-axes angle (α), wherein the teeth are cut in a number of successive processing steps (S1 to S20), wherein, with the advancing of a component in the axial direction (10) of the workpiece spindle, the tooth interstices (7) between the teeth to be created are cut deeper step by step, wherein, between the processing steps, the axial spacing between the tool spindle and the workpiece spindle and a rotational angle (α1 to α19) of a fixed point, for example the center of the tooth interstice (7) situated between a first and a second tooth flank (9, 9'), relative to a fixed point on the cutting tooth (3), for example the center thereof, are changed in such a way that a first cutting edge portion (5") of the cutting tooth (3) acts on a tooth flank portion of the first tooth flank (9) which was created in a preceding processing step in such a way that there is at least reduced material removal relative to other cutting edge portions (5', 5"') of this cutting tooth (3).