Tooth Profile Optimization And Fatigue Reliability Analysis Of The Wind Gears

With the severe energy and environmental problem, the development of new energy has risen to the national strategy. In recent years, wind power equipment has been developed and applied in China. In the wind turbine fault, gear box failure has accounted for 20 percent of the unit failure rate, and stop for a long time, maintenance difficulties. The gear fault has accounted for about 40% of gearbox fault. Therefore, to improve the reliability of the gear is of great of significance in improving the reliability of the whole gearbox.In this paper, a type of 2 MW wind power gear box as the research object, explore related analysis of gear in the statics, the main contents are as follows:(1) Based on RomaxDesigner platform, establish the virtual prototype model of 2MW wind power gear box, the random wind load is converted to the speed-torque load, and the stage 1 planetary gear transmission is determined as the research object.(2) To investigate the effect of manufacturing errors and installation errors to gear stress. Manufacturing error:tooth thickness manufacturing error, tooth root fillet radius manufacturing error, the tooth width manufacturing error, the tooth top circle diameter and root circle diameter manufacturing error. The installation error is the center distance error. Obtain the variation law of the contact stress and the bending stress of each parameter in the error range, and give the suggestion in the actual processing.(3) Taking the sun wheel as an example, the longitudinal load is reduced and uniform distribution. The tooth axial modification and tooth profile modification are used as the means to optimize the tooth. And explore the impact of tooth shape optimization on unit length of normal load, contact stress, bending stress, transmission error and harmonic response. The tooth axial modification is used linear and drum-shape modification, The tooth profile modification is used drum-shape modification. The results show that the longitudinal load, the contact stress, the bending stress, the transmission error and the harmonic response of the gear are obviously reduced.(4) Calculate the fatigue reliability of the contact stress and bending stress of the gear under consideration of the stress cycle times in the model of contact fatigue and bending fatigue cumulative damage, combined with the equivalent normal distribution and stress strength interference theory. And the reliability of the gear is compared with that without considering the stress cycle times. The results show that the reliability of the gear is more than 99%; and the calculation result is more accurate than the result of without considering the stress cycle times.