Eddy Current Sensor Shaft Runout Correction
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Solution Overview
Problem
Existing methods for correcting electrical runout in rotatable machine shafts are inefficient, time-consuming, and often alter the surface finish or dimensions of the shaft, making them costly and ineffective.
Innovation Solution
A method involving the use of an eddy current sensor to measure combined runout, determine the angular location of local valleys, and rework the surface by polishing at these locations, which can be completed in under 35 minutes without significantly affecting the shaft's dimensions or surface finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing methods are used to re-work shaft surfaces to reduce combined runout, then the combined runout measured by eddy current sensor is reduced, but the process becomes complicated and time-consuming, and surface finish is appreciably changed
Solution Approach 1:
The patent divides the shaft surface into discrete angular locations corresponding to local valleys identified in the combined runout measurement. Instead of re-working the entire surface, only specific segmented portions (local valleys) are targeted for polishing, reducing overall re-work time while maintaining precision where needed.
Solution Approach 2:
The patent applies different treatment to different parts of the shaft surface. By identifying specific angular locations of local valleys and applying polishing only to these localized areas rather than the entire surface, the method achieves runout correction while preserving surface finish quality in non-critical areas.
2Manufacturing precision
If existing methods are used to re-work shaft surfaces to reduce combined runout, then the combined runout measured by eddy current sensor is reduced, but the process becomes complicated and time-consuming
Solution Approach 1:
The patent replaces complex mechanical re-work processes with a simplified targeted polishing approach. By using eddy current sensing to identify precise locations and then applying simple polishing only to local valleys, the complex multi-step re-work processes are substituted with a more straightforward method.
Solution Approach 2:
The measurement system itself provides the information needed for correction. The eddy current sensor identifies the locations of local valleys, and this same measurement data directly guides where polishing should be applied, eliminating the need for separate complex measurement and correction procedures.
3Manufacturing precision
If existing methods are used to re-work shaft surfaces, then combined runout is reduced, but shaft dimensions are affected
Solution Approach 1:
The patent applies minimal material removal only at specific local valley locations rather than broad surface re-working. This localized approach corrects electrical runout while preserving the overall shaft dimensions and mechanical tolerances in areas where material removal is not required.
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 method allows for rapid and precise correction of electrical runout, bringing the combined runout within tolerance levels while maintaining the shaft's mechanical tolerances and surface finish, thus improving efficiency and cost-effectiveness.
Implementation Method 1
one or more non-contacting, eddy current proximity sensors to monitor such vibration levels
Data Source
AI summary
A method of removing electrical runout from a measurement surface of a rotatable machine shaft is disclosed. The method includes providing a sensor adjacent to the measurement surface of the rotatable machine shaft, rotating the rotatable machine shaft, measuring a combined runout of the measurement surface, determining an angular location of one or more local valleys on the measurement surface, and re-working the measurement surface at the angular location of the one or more local valleys. Re-work may be by polishing at the one or more local valleys. Various alternative methods are disclosed, as are other aspects.