Common failures of Decanter centrifuge gear boxes include tooth surface wear, tooth surface gluing and abrasions, tooth surface contact fatigue, bending fatigue and broken teeth. The causes are manufacturing errors, poor assembly, poor lubrication, overload, and operational errors. Due to the characteristics of the structure and working principle of the gear, its vibration signal is very complicated, and the vibration fault diagnosis of it needs to be analyzed in both the time domain and the frequency domain. Whether the gear is in a normal or abnormal state, the frequency of gear meshing stiffness always exists.

Therefore, the gearbox should be diagnosed based on the gearing frequency component of the gear. Due to the complexity of the gear signal, the fault has many effects on the vibration signal, especially due to the effect of amplitude modulation and frequency modulation, there are many sideband structures on the vibration spectrum of the gear, which requires specific analysis during the analysis and diagnosis Components to achieve accurate diagnosis of gearbox faults.

The characteristic frequency of the Decanter centrifuge gear box failure is as follows:

1. The normal frequency spectrum shows the 1X and meshing frequencies of all the rotating shafts. There are speed sidebands on both sides of the gear meshing frequency, and the peak value is small.

2. Gear wear. The natural frequency of the gear appears, and there is a speed sideband of the shaft where the worn gear is located. When the wear is obvious, a higher peak sideband will appear near the meshing frequency.

3. Decanter centrifuge gear eccentricity. There is a sideband of higher amplitude near the meshing frequency, indicating that the gear is eccentric or the shaft is not parallel, and the peak of the meshing frequency increases with the increase of the load.

4. The decanter centrifuge gears are misaligned. The vibration of the second or higher harmonics of the meshing frequency is almost always excited, and the peak value at the 2X or 3X meshing frequency spectrum line is large, and there is a side frequency of the rotation frequency interval.