Current situation of fault diagnosis technology for tractor gearbox

Gearbox fault diagnosis technology is also progressing with the development of science and technology and mechanical fault diagnosis technology. In industrial developed countries, gearbox condition monitoring and fault diagnosis technology has received extensive attention; The same is true in China. Many universities and scientific research institutes have carried out research in this field one after another. At present, the research on its diagnostic methods mainly focuses on the following aspects:

1) Vibration and noise diagnosis method

Gearbox vibration and noise diagnosis method is a fault diagnosis method based on obtaining the vibration and noise signals of gearbox to analyze its state information characteristics. Because the vibration and noise radiated by the gearbox during operation are one of the most important attributes of its operation state, their measurement and analysis can better diagnose the cause, location and deterioration degree of faults in the gearbox. This method is considered as the main method to solve gearbox fault diagnosis and has been widely studied and used. Specifically, it can be considered that there are five main reasons:

① Any abnormal phenomenon in the gearbox can be detected by appropriate methods;

② It can effectively diagnose the early weak fault of gearbox and predict the fault development trend;

③ The vibration comes from the gearbox itself, and no additional signal source is required;

④ It can realize real-time fault detection and diagnosis;

⑤ Signal testing and data processing are simpler than other diagnostic methods.

2) Oil diagnosis method

Gearbox oil diagnosis method is a fault diagnosis method based on measuring the micro wear powder in gearbox lubricating oil and analyzing it with chemical theory. The composition, size and number of trace metal powder particles reflected by the state of lubricating oil are essentially the reflection of the wear state of gearbox equipment. Oil diagnosis methods include oil spectrum diagnosis method and Ferrography diagnosis method. The oil diagnosis method is suitable for the detection and diagnosis of wear and pitting faults of components in gearbox. In case of damage and slight wear, the infrared thermal imaging method basically does not reflect. It can be monitored only when the fault reaches a certain severity.

3) Infrared thermal imaging

The infrared thermal imaging method is a diagnostic method by measuring the two-dimensional temperature field signal of the gearbox state. It measures the thermal infrared radiation of the gearbox to the surrounding, obtains the infrared thermal field diagram, and judges whether the gearbox has overheating fault from the thermal field diagram. Infrared thermal imaging method is sensitive to the changes of load, speed and lubrication, especially to the overheating caused by poor lubrication. Therefore, it can achieve good results in these occasions. However, when the internal parts of the gearbox are damaged and slightly worn, the infrared thermal imaging method basically does not reflect ,Only when the fault reaches a certain severity can it be monitored by this method.

In addition, many new diagnostic technologies are emerging and applied to the fault monitoring and diagnosis of gearbox. However, in addition to the vibration and noise diagnosis methods, other diagnosis methods are often constrained by the external environment and the conditions of the diagnosis methods themselves, and are rarely used in practical application.