Gear Cutting Feedback Control for Pressed-In Chip Removal

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Solution Overview

Problem

Manufactured gearings often fail to achieve desired properties due to pressed-in chips during machining, which cause unsatisfactory tooth flank geometry and are not reliably detected by existing measurement methods, leading to potential noise and failure issues in gear transmission.

Innovation Solution

Implementing a method where additional gear machining is performed automatically during the same clamping of the workpiece to remove excess material caused by pressed-in chips, using monitoring to detect and respond to events that exceed predetermined threshold values, ensuring reliable removal of chips without altering the tooth flank end geometry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If monitoring is implemented to detect pressed-in chips during machining, then reliability of gear teeth is improved, but device complexity increases due to additional monitoring systems and automated response mechanisms

Engineering Contradiction:
Improvereliability of gear teethVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a monitoring system that continuously measures parameters during machining and provides feedback to the control device. When a pressed-in chip is detected through monitoring signals, the system automatically triggers an additional machining operation to remove the defect, creating a closed-loop feedback mechanism that improves reliability without requiring manual intervention

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis and self-correction by automatically detecting pressed-in chips through monitoring and triggering additional machining operations without external intervention. The control device autonomously decides when and where to perform corrective machining based on real-time monitoring data, enabling the system to service itself

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If additional gear machining is performed to remove pressed-in chips, then manufacturing precision is improved, but productivity decreases due to extended machining time

Engineering Contradiction:
Improvetooth flank geometryVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

Instead of machining the entire gear surface uniformly, the system performs additional machining only in the specific areas where pressed-in chips are detected. The control device calculates the exact location and extent of defective areas based on monitoring data and limits the additional machining to those regions, performing partial rather than complete re-machining

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The monitoring system detects pressed-in chips during the initial machining pass before the gear is completed. By identifying defects early and performing targeted additional machining immediately afterward, the system prevents the need for more extensive post-processing or rejection of the entire workpiece, thereby preserving productivity

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If monitoring threshold is set low to detect all pressed-in chips, then measurement precision improves, but false alarms increase reducing productivity

Engineering Contradiction:
Improvedetection sensitivityVSAvoidproductivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system dynamically adjusts monitoring thresholds and evaluation criteria based on the specific machining context, gear geometry, and detected signal patterns. Rather than using a fixed low threshold that causes false alarms, the control device adapts the detection parameters to distinguish genuine pressed-in chip events from normal machining variations, maintaining high detection sensitivity while reducing false positives

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

This approach enhances the reliability of gearings by eliminating the disturbance caused by pressed-in chips, ensuring low-noise operation and reducing the risk of damage, while maintaining the desired tooth flank geometry, thus improving the consistency and quality of machined workpieces.

Implementation Method 1

a gear cutting tool, rotating about its axis of rotation and having cutting edges, is brought into a machining engagement, particularly a rolling machining engagement, with the gear teeth

Methodology Applied
Scientific EffectRolling machining:

Implementation Method 2

monitoring is carried out that responds to the event of an already removed chip being pressed into a machined tooth flank of the gear

Methodology Applied
Scientific EffectVibration monitoring: Vibration

Implementation Method 3

due to the temperatures typically occurring during machining, a kind of cold welding or friction welding occurs with the workpiece material

Methodology Applied
Scientific EffectCold welding: Friction Welding

Data Source

PatentEP3710192B1Method for cutting a gear and gear-cutting machine
Publication Date: 2022.07.27 GLEASON PFAUTER MASCHFAB
  • EP3710192B1 patent drawingFigure 1a~1c
  • EP3710192B1 patent drawingFigure 2
  • EP3710192B1 patent drawingFigure 3

AI summary

The invention relates to a method for cutting a gear (2) in a workpiece held in a setup, in which a gear-cutting tool (1) that rotates about its axis of rotation and has cutting edges (5) is brought into in particular rolling subtractive cutting engagement with the gear rotating about its axis of rotation, in order to create a predefined tooth-flank end geometry in one or more cutting passes, wherein, during the cutting pass creating the tooth-flank end geometry, monitoring that responds to the event of a removed chip (4) being pressed into a cut tooth flank of the gear on account of the in particular rolling cutting is effected, and when the monitoring responds, an additional gear-cutting operation that removes a material projection, formed by the pressed-in chip (4') upon the event occurring, is carried out, in particular automatically, over the tooth-flank end geometry, this taking place in particular in the same setup of the workpiece and in particular using the gear-cutting tool itself. The invention also relates to a computer program product having a control program for carrying out the method, and to a gear-cutting machine therefor.