Automated Toothed Member Machining With In-Process Tool Correction

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Solution Overview

Problem

The manufacturing of toothed members, such as curvic couplings, in gas turbine engines requires precise machining with tight tolerances, leading to time-consuming and costly manual measurement and setup operations due to the complexity of the process.

Innovation Solution

A method involving machining a workpiece to a predetermined partial depth, comparing computed parameters to nominal dimensions, modifying the cutting tool geometry to correct deviations, and further machining to achieve the desired tooth pattern within tolerance, utilizing automated systems and NC machines to minimize manual intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual measurement and setup operations are used to ensure tight tolerances, then manufacturing precision is improved, but productivity deteriorates due to time-consuming operations

Engineering Contradiction:

Improvetoothed member dimensional accuracyVSAvoidmanufacturing cycle time

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The system performs self-measurement and self-correction by using the cutting tool itself to measure the workpiece geometry and automatically adjust its own parameters through redressing, eliminating the need for separate manual measurement and adjustment operations

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Manual mechanical measurement operations are replaced with automated optical or sensor-based measurement systems integrated into the machining center, and manual tool adjustment is replaced with automated tool redressing mechanisms

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If multiple manual interventions are made during machining to ensure tight tolerances, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improvetoothed member dimensional accuracyVSAvoidmachining process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The measurement, inspection, and tool adjustment functions are merged into a single integrated automated system that operates continuously during the machining process, eliminating the need for separate manual intervention steps

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system implements closed-loop feedback by continuously measuring the workpiece geometry, comparing it to target specifications, and automatically adjusting cutting tool parameters to correct any deviations, ensuring tight tolerances without manual intervention

Inventive Principle:

Principle #23Feedback

3Productivity

If automated machining is implemented to reduce manual intervention, then productivity is improved, but manufacturing precision may deteriorate

Engineering Contradiction:

Improvemanufacturing cycle timeVSAvoidtoothed member dimensional accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The automated system performs self-correction by using real-time measurement data to automatically adjust cutting tool geometry through redressing, ensuring that precision is maintained throughout the automated machining process without manual intervention

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Manual skill-based adjustment operations are replaced with automated computer-controlled redressing mechanisms that precisely replicate and maintain tool geometry, ensuring consistent precision across all automated machining operations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11229965B2System and method for automated machining of toothed members

Publication Date: 2022.01.25 PRATT & WHITNEY CANADA CORP

AI summary

A method for machining a workpiece to provide a toothed member having a desired tooth pattern. The workpiece is machined to a first depth using a cutting tool, thereby forming a semi-finished tooth pattern, the first depth less than a full depth to which the workpiece is to be machined to provide the desired tooth pattern. Dimensions of the semi-finished tooth pattern are acquired and compared to nominal dimensions. If the acquired dimensions are not within a tolerance of the nominal dimensions, the geometry of the cutting tool is modified for correcting deviations of the acquired dimensions from tolerance and the workpiece further machined by the modified cutting tool. Once the dimensions of the semi-finished tooth pattern are within tolerance, the workpiece is machined to the full depth for providing the desired tooth pattern.