Based on the actual engineering application, the dynamic characteristics of gear transmission system and the methods of vibration reduction and noise reduction are studied from different excitation factors. The conclusions are as follows
① The influence of friction force on the dynamics of gear system is analyzed. A six degree of freedom accurate dynamic model considering the influence of tooth surface friction is established. Considering the time-varying of meshing stiffness and tooth surface friction coefficient, the numerical simulation is carried out by using Runge Kutta method. The dynamic characteristics of gear system excited by friction are analyzed, and the conclusion is verified by experiments. The results show that the gear friction can restrain the dynamic excitation in the direction of meshing line to a certain extent, and aggravate the system vibration in the direction of friction, and further clarify the influence law of friction excitation on the dynamic characteristics of gear transmission;
② This paper studies the gear transmission system excited by the direction transmission error of the meshing line. The coupling dynamic simulation model of mechanical transmission is established. The modal flexibility under the excitation of gear and main reducer gear is analyzed, and the natural mode vibration mode is calculated. Taking the gear transmission error as the excitation, the dynamic response of the bearing force of each bearing and the acceleration response of the box surface are obtained. The genetic algorithm is applied to the optimization design of the micro modification of the gear. Taking the gear transmission error as the objective, the tooth profile modification scheme of the gear system is optimized. The sensitivity analysis verifies that the transmission error of the optimized tooth profile has a good influence on the manufacturing tolerance The improvement of rod property provides a solution for vibration reduction and noise reduction of batch products;
③ The dynamic characteristics of gears excited by rattling force are studied. In this paper, the lumped parameter method is used to establish the simulation model of torsional vibration slapping considering the factors of load fluctuation, gear backlash, clutch multi-stage stiffness and drag torque. The dynamic analysis equation is solved by numerical calculation method. The influence of gear backlash, drag torque, clutch multi-stage stiffness, transmission shaft flexibility and other factors on the dynamic characteristics of gearbox rattling is analyzed, and the slapping strength is evaluated Degree;
④ The modulation sideband frequency analysis model of planetary gear train is established. The influence of the basic parameters such as the number of teeth, meshing phase and the order of excitation on the sideband frequency characteristics of planetary gear train is discussed. A general judgment method for estimating the sideband frequency characteristics of planetary gear train based on the known parameters is obtained. The noise caused by asymmetric sideband frequency is improved by this method. The experimental results verify the effectiveness of the proposed method The correctness provides an important reference for the side band noise control of planetary drive;
⑤ The inherent dynamic characteristics of the manual transmission are experimentally studied. The transmission error and dynamic corresponding simulation and experimental results are tested and compared to verify the effectiveness of the system simulation design.