Table 2 Gear status at different monitoring times.

From: Time-weighted kernel density for gearbox residual life prediction

Monitoring time

RMS curve

Monitoring gear status

\(t \in \left[ {0,10} \right]{\text{h}}\)

Showing a gradual decrease

Initial meshing stage

\(t \in \left[ {10,68} \right]{\text{h}}\)

Showing a gradual increase

Normal fatigue wear stage

\(t \in \left[ {68,77} \right]{\text{h}}\)

Starting to increase sharply

Fatigue and wear increase until the tooth is broken