Dynamic Response Analysis For 1.5MW Wind Generator Gear System Based On The Thermal Analysis

The gear transmission system is the key part of the wind turbine, which can transmit the wind load to the generator and make it get the corresponding speed. The gear transmission system performance directly determines the performance of the wind turbine. The speed of the high speed gear system is fast and the load is heavy. The gear thermal equilibrium state have important influence on the vibration and failure of the gear transmission. Therefore, thermal behavior must be considered in the design of high speed gear. Vibration and noise are always caused during the power transmission due to the deformation, heat distortion, manufacturing errors and installation error of the gear tooth. Tooth profile modification is an effective method to optimize contact patterns, compensate for manufacturing errors and reduce the vibration and noise of gear system. The main contents are as follows:(1) In this paper, the finite element model of the involute spur gear is established based on the finite element software. The steady temperature field, the transient temperature field distribution and the steady temperature field of gear varying with the power, the speed, the friction coefficient and the oil temperature are systematically studied. Finally, the thermal field analysis results are introduced into the structural field to obtain the thermal deformation of gear.(2) According to the results obtained by thermal analysis, static contact analysis of cold state and thermal state gear is carried out to study the variation regular of contact deformation and contact stress of gear during a meshing period. And according to the angle displacement of gear, the transmission error and the time-varying stiffness during a meshing period are calculated.(3) Gear tip modification was carried out according to the contact deformation results of cold state and thermal state gear, the temperature field and thermal deformation under different gear modification value are analyzed. The variation of contact deformation and contact stress of thermal state gear after modification is studied. The transmission error and the time-varying stiffness of thermal state gear after modification during a meshing period are calculated.(4) The dynamic model of spur gear is established by using centralized parameter method. The calculation results of the transmission error and the time-varying stiffness are brought into the model. The dynamic response of gear is obtained by solving the dynamic differential equations based on Matlab programming. The gear heat distortion reduces the gear dynamic performance, and the tooth profile modification can improve the gear dynamic performance. Considering the effect of thermal deformation of modification value is more better than that without considering the thermal deformation.In this paper, the thermal behavior, contact behavior and dynamic performance of the gear are studied by numerical simulation method. The research results can provide reference for the design of gear structure.