Gear modification is the key technology to reduce the vibration, noise and improve the reliability of gear transmission system. Since the tooth profile modification was put forward, scholars at home and abroad have carried out extensive and in-depth theoretical research and experimental analysis on the tooth profile modification technology, and put forward a variety of modification theories and methods according to their own understanding and practice. Gear profile modification includes two aspects: profile modification in the direction of tooth height and profile modification in the direction of tooth width. Among them, profile modification is the most widely used method. The tooth profile modification can effectively alleviate the sharp change of meshing stiffness caused by the change of meshing teeth number, so as to reduce the meshing impact and the vibration and noise of the gear transmission system.
The main task of tooth profile modification is to determine the three elements of tooth profile modification: modification amount, modification length and modification type. The determination of these three factors is a complex problem. At present, the research of tooth profile modification mainly focuses on two aspects: the research of tooth profile modification based on the static characteristics of gear transmission system and the research of tooth profile modification based on the dynamic characteristics of gear transmission system. In the study of tooth profile modification based on the static characteristics of gear transmission system, the influence of tooth profile modification on static transmission error, load distribution between teeth, bending and contact fatigue strength is generally analyzed by analytical method or by means of finite element software. This method can obtain better vibration reduction effect under quasi-static load. In foreign countries, it is first pointed out that the gear load changes in a stepped way. This method can be used to evaluate the influence of modification parameters on the meshing characteristics of gears, and a long modification method of tooth profile is proposed. It is pointed out that the interference phenomenon caused by gear deformation should be avoided in gear profile modification. A similar method is used to study the influence of tooth profile modification, and it is pointed out that neither long modification nor short modification can reduce the static transmission error when the load changes. The influence of tooth profile modification parameters on the static transmission error is studied, and the reduction of the fluctuation of static transmission error is taken as the optimization objective. The corresponding modification amount and modification length are obtained when the static characteristics are optimal. It is pointed out that the dynamic characteristics in gear transmission should be considered in the next study of tooth profile modification, and the external factors should be considered Part load and speed change.
Different methods are used to study the optimal tooth profile modification parameters corresponding to the minimum peak value of static transmission error, and the simulation is carried out based on the nonlinear dynamic model. Aiming at the goal of no interference between teeth and minimum load coefficient in the direction of teeth, the parameters of tooth profile modification are determined.