Rotor-Stator Gap Inspection for Rotary Machine Wedge Cracks
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Solution Overview
Problem
Conventional inspection methods for rotary electric machines require disassembly of the rotor from the stator, leading to prolonged inspection periods, reduced utilization factor, and potential damage to the stator and rotor, with inefficient movement and positioning of inspection devices due to rotor stop angle variability and wedge positioning constraints.
Innovation Solution
An inspection device and system that allows for remote inspection by inserting into the gap between the stator and rotor, utilizing a base frame with traveling bodies, a probe, radial-movement, and circumferential-movement portions to adjust the probe's position, enabling efficient inspection without disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotor is pulled out from the stator for inspection, then the wedge crack inspection can be performed, but the inspection period is prolonged and the utilization factor is reduced
Solution Approach 1:
The inspection device is extracted from the conventional approach of removing the rotor, instead being inserted into the gap between stator and rotor to perform inspection in-situ, eliminating the need for rotor disassembly while maintaining inspection accuracy
Solution Approach 2:
An inspection device acts as an intermediary tool inserted into the gap between stator and rotor, enabling crack detection without direct contact with the rotor wedge, thus avoiding rotor removal while achieving inspection objectives
2Reliability
If the device is placed at multiple teeth of the stator to inspect all wedges, then complete inspection coverage is achieved, but the inspection efficiency is reduced
Solution Approach 1:
The inspection device incorporates movable components that enable dynamic positioning and scanning across multiple wedge locations without requiring physical repositioning of the entire device, allowing complete inspection coverage while maintaining high inspection speed
Solution Approach 2:
The inspection device is designed with multi-functional capabilities to inspect multiple wedge positions from a single placement location, eliminating the need to move the device between teeth while achieving complete inspection coverage
3Measurement precision
If the rotor is rotated to adjust the rotation position for wedge inspection, then the probe can contact the wedge surface, but the inspection efficiency is reduced
Solution Approach 1:
The inspection device includes movable positioning mechanisms that allow the probe to dynamically adjust its position and contact the wedge surface without requiring rotor rotation, maintaining measurement precision while improving inspection efficiency
Solution Approach 2:
The inspection device is segmented into movable components that can independently adjust the probe position relative to the wedge, enabling precise contact without rotating the entire rotor assembly
4Ease of operation
If the device is attracted at a tooth of the stator, then the device can be positioned for inspection, but the rotor wedge range where inspection can be performed is constrained
Solution Approach 1:
The inspection device incorporates dynamic positioning capabilities that allow it to move along the stator circumference after initial attraction, expanding the inspection range to cover multiple rotor wedge positions while maintaining ease of initial positioning
Solution Approach 2:
The inspection device is designed with universal positioning capabilities that enable it to inspect wedges at multiple rotor positions from a single stator tooth attraction point, enhancing adaptability while maintaining operational simplicity
Data Source
AI summary
An inspection device inspects an inspection target part by being inserted into a gap between an inner circumferential surface of a stator and an outer circumferential surface of a rotor of a rotary electric machine. The inspection device includes: a traveling body which is attached to a base frame and moves the base frame in an axial direction in the gap; a probe which inspects the inspection target part; a radial-movement portion which moves the probe in a radial direction perpendicular to the axial direction and a circumferential direction; and a circumferential-movement portion which moves the probe in the circumferential direction in the base frame.