Active Torque Control for Gear Lapping Run-Out

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Solution Overview

Problem

Conventional gear lapping machines face limitations in actively controlling torque, leading to significant dynamic motion and torque behavior that can compromise tooth modification performance and run-out accuracy, often resulting in sub-optimal results where optimal tooth flank shape may worsen run-outs or vice versa.

Innovation Solution

An active torque system that uses real-time motion-transmission-error measurements to calculate corrective torque components, which are applied through spindle motors or brakes, combining these with conventional torque to reduce or eliminate gear set motion transmission errors and improve run-out performance without compromising tooth-to-tooth performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional passive torque control is used in gear lapping, then the lapping process can maintain average torque levels, but dynamic torque components caused by machine response to gearset motion errors cannot be controlled, leading to compromised run-out accuracy and tooth modification performance

Engineering Contradiction:
Improverun-out accuracyVSAvoidtorque control system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements active torque control by measuring actual gearset motion errors and using this feedback to calculate and apply corrective torque components in real-time, transforming the passive torque control system into an active feedback-controlled system that dynamically compensates for motion errors

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses the gearset's own motion errors as the basis for generating corrective torque, allowing the system to self-correct its performance by utilizing its measured deviations rather than requiring external intervention or complex mechanical adjustments

Inventive Principle:
Principle #25Self-service

2Productivity

If spindle speed is increased to improve productivity, then material removal rate increases, but passive physics-based dynamic torque components become more dominant, worsening run-out performance

Engineering Contradiction:
Improvematerial removal rateVSAvoidrun-out performance
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent transitions from static average torque control to dynamic active torque control that adapts in real-time to changing operating conditions, allowing the system to maintain precision even at higher spindle speeds where dynamic effects become more significant

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system dynamically changes torque parameters based on measured motion errors, adjusting the corrective torque magnitude and timing according to the actual operating conditions and spindle speed, thereby maintaining control across varying productivity levels

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If V and H positions are changed to shift contact pattern to heel or toe positions, then tooth surface contact position is modified, but G-axis position must also be changed to maintain backlash, complicating the lapping process

Engineering Contradiction:
Improvecontact pattern positionVSAvoidcoordinate control complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The active torque control system measures the actual contact pattern position and motion errors resulting from V, H, and G position changes, then applies corrective torque to compensate for deviations, reducing the sensitivity to precise coordinate control and simplifying the overall process control

Inventive Principle:
Principle #23Feedback

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

The active torque system effectively reduces or eliminates run-out and other longer-term motion transmission errors, enhancing the lapping process while maintaining short-term tooth-to-tooth performance, by counteracting passive physics-based dynamic torque components with controllable corrective torque.

Implementation Method 1

An active torque system that uses real-time motion-transmission-error measurements to calculate corrective torque components, which are applied through spindle motors or brakes

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

lapping compound, which can be a mixture of oil (or water) and silicon carbide or similar abrasive, is sprayed, injected or poured into the meshing zone

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2861369B1Active torque method of lapping gears
Publication Date: 2018.06.13 THE GLEASON WORKS
  • EP2861369B1 patent drawingFigure 1
  • EP2861369B1 patent drawingFigure 2

AI summary

Method and apparatus for lapping gears which includes an active torque system to substantially improve the lapping process with respect to run-out and other longer-term motion transmission errors without compromising tooth-to-tooth performance. Motion transmission error measurements provide the basis for calculating a corrective active torque component which is combined with conventional process torque to reduce or eliminate part run-out.