Dynamic Meshing Performance Simulation And Reliability Analysis Of Double Planetary Vertical Mill Reducer

Vertical mill is widely used in production industry of mining machinery, such as coal, cement and chemical. As a core component of vertical mill, Vertical mill reducer has an important influence on the comprehensive performance of vertical mills. With the development of science and technology, vertical mill develops towards lightweight, high power, low vibration and high reliability. Therefore, higher requirements are proposed for the dynamic response, meshing performance and reliability. Nevertheless, the complicated dynamic load, fatigue failure and resonance invalidation of double planetary vertical mill reducer gear system have a strong impact on the normal operation. Thus, the dynamic meshing performance simulation and reliability analysis of double planetary vertical mill reducer have important theoretical significance and practical engineering value.The thesis is derived from the National Key Technology R&D Program. The dynamic excitation, tooth profile optimization, vibration characteristics, fatigue and resonance reliability of double planetary vertical mill reducer gear system are researched comprehensively. The main research work in this paper can be summarized as follows:(1) The finite element model of double planetary vertical mill reducer gear system is built by using the APDL of the numerical simulation software ANSYS. The natural frequency and natural mode of gear system are obtained by finite element modal analysis. On these basis, the dynamic response of gear system is analyzed by mode superposition method. The vibration displacement, velocity and acceleration RMS value of evaluation points are obtained, then the vibration curve of time domain and frequency domain are plotted.(2) The model of double planetary vertical mill reducer transmission system is established by using the software ROMAX. Then the transmission error, tooth surface load, stress distribution of gear tooth are analyzed. By the tooth profile optimization of planetary gear pairs with genetic algorithm, the optimal value of modification parameters are obtained. The meshing performance and dynamic response of the double planetary gear reducer before and after optimization are contrastively analyzed.(3) The bending fatigue reliability, contact fatigue reliability and sensitivity of bevel gears and planetary transmission gears of double planetary vertical mill reducer are analyzed by the second moment algorithm. Using Monte-Carlo method, the static strength reliability and sensitivity of two planet carriers are analyzed. Then the fatigue reliability analysis model of transmission system is established, and the fatigue reliability is obtained.(4) Parametric model of double planetary vertical mill reducer structure system is established. Select some material and dimension parameters as random input parameters, set the approach rate between excitation frequency and the natural frequency as output variables. Using response surface method, the approximate expression of the input and output is obtained. Using the Monte-Carlo simulation technique for sampling, resonance reliability and sensitivity of structure system is obtained.