Compressor Cover Wear Markers for Accurate Blade Erosion Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring wear in centrifugal compressor parts, particularly in helicopter turbine engines, suffer from inaccuracy and difficulty in accessing rotating parts, leading to erroneous diagnoses and inefficient maintenance.
Innovation Solution
A centrifugal gas turbine compressor with an abradable coating on the impeller cover featuring strategically placed markers of varying depths, allowing for precise wear measurement through endoscopy without engine removal, enabling targeted maintenance by correlating cover wear with adjacent parts' erosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If endoscopy is used to measure wear at the leading edge of impeller blades, then wear measurement can be performed without removing the motor, but the measurement accuracy is poor and access to blades is difficult
Solution Approach 1:
The patent introduces an intermediary element (the marker on the cover) that mediates between the difficult-to-access impeller blades and the accessible cover. Instead of directly measuring the blades, the marker on the cover serves as a proxy that indicates blade wear through their relative motion, enabling accurate wear assessment without direct access to the blades during rotation.
Solution Approach 2:
The patent creates a copy or representation of the blade wear condition on the cover through the marker system. The marker's position and depth changes reflect the relative motion between the cover and blades, providing a measurable copy of the wear condition that can be observed without direct access to the blades themselves.
2Reliability
If a wear marker is placed on rotating parts, then wear can be monitored, but the placement is difficult due to high stresses in operation
Solution Approach 1:
The patent applies preliminary action by placing the marker on the cover during the manufacturing process, before the compressor enters service. The marker is installed on the stationary cover rather than on rotating blades, avoiding the high-stress environment during operation. This preliminary placement ensures the marker is securely positioned and ready for future wear monitoring without exposing it to operational stresses that would make placement difficult.
3Measurement precision
If the impeller cover is used as a marker location, then wear measurement becomes accessible and reliable, but the cover itself is subjected to erosion
Solution Approach 1:
The patent applies local quality by concentrating the wear indicator function in a specific localized area (the marker) on the cover, rather than requiring the entire cover to be resistant to erosion. The marker is positioned in a location that is accessible for measurement while the cover material itself is designed with appropriate wear resistance properties. This localized approach allows the cover to be subject to controlled erosion while maintaining measurement capability through the marker system.
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 solution provides accurate and accessible wear measurement, facilitating timely replacement of worn parts and reducing maintenance errors by correlating cover wear with impeller blade erosion.
Implementation Method 1
the cover, which is covered with an abradable coating
Implementation Method 2
Wear by erosion affects the main parts of the air stream of an engine
Implementation Method 3
endoscopy examinations are carried out successively over time; at each examination, an endoscope is introduced into the compressor and an active end of the endoscope is positioned opposite the marking(s) to supply an image signal of the markings
Data Source
Figure 1
Figure 2~5
Figure 6
AI summary
The aim of the invention is to take an accurate measurement of the erosion of compressors, without removal of the engine, and to provide for simple installation. For this purpose, it has been observed that erosion takes place in the elbow of the cover and the progress of said erosion can thus enable the monitoring of erosion to the other parts of the compressor, in particular the blades of the impeller. Generally, a centrifugal compressor (1) of a gas turbine with a radial air inlet comprises, in particular, an impeller provided with blades and a cover (12) for the flow of air through the impeller blades. The cover (12) is covered with an abradable coating and has an annular area (120, 121) of the elbow (12a) in a substantially median portion. Hollow markings (M1 to M3) of determined depths have been machined in the abradable coating of this area (12a, 120), preferably in groups (G1, G2). Endoscopic examinations are carried out successively to provide an image signal of the markings. Endoscopic signal processing provides a number of remaining markings and a decision criterion for removing the engine is applied to same.