The gearbox is composed of gears, transmission shafts, bearings and box structures. Because the box structure is sealed, it is generally not easy to fail. The failure mainly occurs in the gears, transmission shafts and bearings. Generally, the failure of the gearbox Have:

1. Tooth error

It refers to the deviation of the gear tooth profile from the ideal tooth profile, including manufacturing errors, installation errors and errors generated in the working process. The tooth profile error is mainly manifested as plastic deformation of the tooth surface, uneven surface wear and surface fatigue.

2. Gear wear evenly

It refers to the friction damage of materials in the meshing process when the gear is used, including uniform wear of abrasive particles and uniform wear of corrosion.

3. Broken tooth

Broken teeth is a serious fault of gears, mainly in two forms: fatigue broken teeth and overloaded teeth. Generally, fatigue broken teeth are more common.

4. Shaft misalignment

Refers to the shafts at both ends of the coupling due to problems in the design, manufacture, installation or use process, the shafts are parallel but misaligned, causing the gears on the shaft to produce distributed tooth profile errors.

5. Shaft bending

When the shaft in the gearbox is slightly bent, it will cause a tooth profile error on the gears on that shaft. When the shaft is severely bent, the gearbox will generate large impact energy, causing serious consequences, which is a more serious form of failure.

6. Shaft imbalance

It refers to the unbalanced vibration of the shaft due to the existence of eccentricity, which can be caused by deformation after manufacture, installation and use. Shaft unbalance faults can cause tooth profile errors in gear drives.

7. Axial movement

When there are two helical gears engaged in meshing at the same time on the same shaft, and there is no good positioning and locking device in the axial direction, sometimes the phenomenon of axial play occurs, which is mainly caused by the unbalanced axial force. of. Axial play will seriously affect the accuracy and stability of gear transmission, and may also cause impact wear on the end face of the gear teeth.

8. Box resonance

Box resonance is a resonance phenomenon caused by the excitation of the natural frequency of the gearbox box by the impact energy. The resonance of the box body produces a large amount of shock vibration energy, which is a very serious fault and is generally caused by the outside.

9. Bearing fatigue spalling and pitting corrosion

When the shaft rotates, the inner ring and the outer ring and the rolling elements will have mechanical shock during the contact process, resulting in a force with a large fluctuation range of the shock pulse. When the rolling bearing in the gear box fails, its energy is much smaller than the vibration energy generated by the gear. , making it difficult to diagnose.

Fault diagnosis method of gearbox

Gearboxes are widely used. If there is a fault, it needs to be diagnosed in time. Generally, the reasons for gearbox failures mainly include design problems, improper operation, and faults or defects in adjacent conditions. The methods for diagnosing gearbox faults are as follows:

1. Through the dynamic signals such as vibration, noise and oil temperature generated during the operation of the gear, the signal processing method is used to complete the analysis and diagnosis of the fault.

2. According to the friction and wear theory, by analyzing the metal composition in the lubricating oil, it is judged which part of the material is, so as to judge whether it is a normal phenomenon. 3. Spectrum analysis method. When the gearbox fails, the fault information contained in the vibration signal usually appears in the form of modulation. By demodulating the fault information, you can know where the fault lies.