Gear transmission is one of the most widely used mechanical transmission forms. It plays a very important role in machinery, aerospace, shipbuilding and other industries. With the development of gear transmission system towards high speed and heavy load, the vibration of gear transmission system is intensified under the combined action of internal and external excitation. A large part of the vibration of mechanical equipment comes from this. The vibration leads to wear, fatigue damage, noise and actual movement law deviate from the theoretical movement law, resulting in errors, reducing the safety, reliability and work quality of the machine, and even leading to the damage of gears or other parts. In the fields of machinery, aerospace, ship and other applications, it is required to solve the vibration problem caused by gear transmission system. At present, the vibration and noise of the gear transmission system has become the primary factor affecting the competitiveness of products, thus enhancing the urgency of the theoretical and technical research on gear vibration reduction and noise reduction. The dynamic problems of gear transmission system related to vibration have been paid great attention by the academic and engineering circles at home and abroad.
The gear drive system has the following features:
1) The rotating speed is high, sometimes it can reach hundreds of thousands of revolutions, and the dynamic behavior is very complex;
2) The system is complex, from prime mover to(including bearings, gears, shafts, etc.) to load, with complex and diverse structure;
3) The difficulty of modeling mainly lies in many nonlinear factors, such as gear backlash, meshing stiffness and tooth profile error, bearing clearance and different structural forms, as well as different stiffness forms caused by different supporting forms of rotor.
The above characteristics make the study of the dynamics of gear transmission system become a hot topic in the past century, and a complete theoretical system has been formed in the research process. The research of the dynamics of the gear transmission system focuses on the dynamic characteristics of the gear meshing process and aims at improving the dynamic behavior of the gear transmission system. Through the study of the dynamics of the gear transmission system, it is of great engineering significance to reduce the vibration and noise of the gear transmission system and improve its safety, reliability and work quality.
In the study of the dynamics of gear transmission system, there are two main contents. One is the dynamic modeling and analysis of the gear itself, which takes the meshing gear pair as the research object. Generally, the influence of other structures in the gear transmission system is simplified or ignored, and the dynamic characteristics of gear teeth and the dynamic modeling of the gear transmission system are mainly discussed. The second is the dynamic research of the gear rotor bearing system. This part of the research takes the gear rotor bearing system of gear transmission as the research object, involving a wide range of contents, mainly including gear dynamics, rotor dynamics and hydrodynamic lubrication theory, etc. the structure of the system is more complex, involving the rotor and support system besides the gear.