Rough Set Neural Network Feature Extraction and Pattern Recognition of Shaft Orbits Based on the Zernike Moment

Table 1

Shaft orbit shapes and potential failure types.

No.	Shaft orbits	Failure type
1	Ellipse	Unbalanced or main axis is not straight
2	Banana and outer “8”	Misalignment
3	Petal shape	Vortex band of draft tube
4	Inner “8”	Oil whirl
5	Two separate ellipses	Bistability
6	Protruding burr	Static and dynamic component friction