When the gear system has tooth profile error, tooth surface roughness is too high, the lubricating oil film is too thin or there are impurities in the lubricating oil, the gear fatigue pitting corrosion will be more likely to occur. When the tooth surface fatigue pitting corrosion exists, it will often aggravate the tooth surface wear, thus affecting the accuracy and life of gear transmission, and also shorten the service life of mechanical equipment including gearbox, thus affecting the work progress and efficiency of the whole mechanical equipment. If the gear fatigue pitting is not found in the early stage of failure, the early micro pitting will continue to deteriorate into destructive pitting, which will cause tooth surface spalling and eventually lead to tooth fracture. When the tooth surface spalling or tooth fracture occurs, the effective contact area of the gear mesh will be reduced, and the bearing capacity of the gear system will be reduced successively, which will cause greater noise and more severe vibration of the system, and eventually lead to the failure of the gear transmission function.
As the main functional component of gear transmission system, gear will directly lead to the decline of working safety and reliability of the whole system when it is damaged or failed, and even lead to serious safety accidents. In addition, the proportion of common gear failure is given. The proportion of gear pitting failure in all types of gear failure is 31%. Therefore, in the process of gear system operation, gear pitting failure has a great probability.
The purpose of gear fault diagnosis is to find the small fault of gear as soon as possible, avoid major accident and reduce unnecessary economic loss. In the case of considering the complex system of gear, bearing, transmission shaft and bearing support at the same time, the dynamic characteristics of gear system are comprehensively studied by using the whole gear system as the analysis object, so that the gear simulation model is closer to the actual gear system.
Based on vibration theory, gear system dynamics studies the basic law of gear transmission system vibration, improves the dynamic behavior of gear transmission system, and provides theoretical basis for the design and manufacture of high-performance gear system. In the experimental research of gear system, monitoring and analyzing the vibration signal of gear system is the most commonly used means in gear fault diagnosis. This is mainly because the vibration signal as the carrier of gear state information contains the important characteristic information of healthy gear system and fault gear system, which is the sign of judging whether the gear system is in fault System vibration signal plays an important role in gear fault diagnosis.
The experimental research on gear system can verify the rationality of the simulation model and put forward reasonable suggestions for the modification of the simulation model. In addition, the experimental research on the status of the gear pair under the actual working conditions can more accurately and truly grasp the dynamic characteristics of the gear running state. Therefore, it is of great significance to study gear system dynamics and gear system experiment.