Research on Fault Evolution Feature Extraction and Identification of Sun Gear Cracks in Planetary Gearbox Based on Volterra High-Order Kernel Generalized Frequency Response Graphic Analysis

Figure 11

Bispectral three-dimensional map with a memory length of 4.

(a) Nondefective gear

(b) 0.2 mm crack depth

(c) 0.4 mm crack depth