Gear transmission is the most widely used mechanical transmission mode, which is widely used in mechanical electronics, mining metallurgy, automobile transportation, aerospace and other fields. With the development of modern industrialization, more and more attention has been paid to the vibration and noise of mechanical equipment, including gearbox. The main source of the vibration and noise of the gearbox is the interaction between the teeth when meshing. The relevant research shows that the gearbox is mainly the equipment with structural noise. According to the analysis of the transmission path of the vibration and noise, it can be divided into three main ways: first, the meshing sound generated during the meshing process of the gear is transmitted to the gearbox in the form of solid sound through the gear, shaft and bearing, etc, Through the vibration of each wall of the box, it radiates to the outer space of the gearbox to form the so-called first air sound; secondly, the meshing sound produced by the gearing process is directly radiated to the inner space of the gearbox, and then transmitted to each wall of the box to make its vibration radiate noise to the outer space of the gearbox, forming the so-called second air sound; thirdly, the meshing sound radiates outward through various gaps existing in the gearbox. The results show that 90% ~ 95% of the radiated sound energy of the gearbox is the first way. Therefore, the optimization design of gearbox is an important research content of the optimization design of vibration reduction and noise reduction of the whole gearbox.
Scholars at home and abroad have carried out extensive research work on the optimization design of gearbox vibration reduction and noise reduction, but the deeper the research, the more difficult problems will be encountered. So far, many research work is still in the stage of theoretical and experimental research, numerical simulation method of vibration and noise, and so on. On this basis, the vibration and radiation noise characteristics of gearbox are explored, And look for the weak link, carry on the corresponding structure improvement work. In view of the common problems such as the unsynchronized optimization of vibration and noise and the blindness of structural improvement, this paper uses the principle of vibration velocity method, the finite element method, the contribution analysis and other methods, and on the basis of considering the vibration and noise characteristics of the gearbox, uses the optimization solver to optimize the solution and improve the design.
(1) The contribution of structural mode of a gearbox is analyzed, and the third mode is identified as the main contribution mode. The contribution of acoustic panel to gearbox is analyzed, and the main noise radiation source is determined as two non support surfaces.
(2) Combined with the principle of the vibration velocity method, based on the calculation of the finite element vibration response of the gearbox, the solution of the radiated sound power level of its non support surface is realized. This parameter can better represent the vibration and noise of the whole gearbox.
(3) By using the optimization solver of ANSYS software, the optimal solution of vibration reduction and noise reduction of gearbox is realized, and the optimal wall thickness combination of gearbox is obtained. The related research of this paper provides reference for the vibration and noise control of gearbox.