Study On Antifatigue Mechanism Of Wind Power Yaw Drive Reducer

In recent years, the wind power generation is sudden appearance in energy industry, and has been growing at a rate of 30% per year. However, reducers for wind power generation, there is, the yaw drive reducer and the pitch regulated drive reducer always endure outer dynamic random load with time. And the dynamic stress may cause fatigue damage and failure. To improve the reliability, the method that increasing the right Safety Coefficient or reducing the allowable stress is always adopted in traditional yaw drive reducers based on the design for static strength. The anti-fatigue design is not adopted, so the reliability and security of yaw drive reducer is not advanced, and is not suitable for the light weight design of yaw drive reducer.Therefore, in this paper, the dynamic, fatigue and modal simulation analysis for planet transmission of yaw reducer are discussed with the numerical simulation. It has great referential value for antifatigue design of yaw drive reducer. The main contents and innovations in this thesis are as follows:(1) By analysis of virtual assembly and simulation for the total assemble model of wind power yaw reducer, the result shows that the simulation proves desirable, also provides an excellent assurance of an application of the finite software ANSYS to analyze the contact and fatigue condition.(2) The contact stress distribution and equivalent stress distribution are obtained by simulating the change of contact stress in the process of planetary gear operation. The result shows that: the boundary of contact stress is pushed further out as the gears are being engaged, and the maximum stress in the engagement process is 460MPa, but it is still less than the material yield limit of the planetary gear.(3) The fatigue life and cumulative fatigue coefficient are obtained by analyzing and processing the fatigue simulation results. The calculation results also indicate that the anti-fatigue property of planetary gear based on 42CrMo is in accord with the engineering design requirement. certain torque condition..(4) The modal analysis of yaw reducer result indicates that the natural frequency of yaw drive reducer under the existing constraint conditions drifts from excitation frequency of the moving components in a rotor, and the corresponding critical speed get well below the normal level of yaw reducer, so it has trouble producing the resonance.