Research On Vibration Characteristics For Wind Power Generator With Gear Root Crack

Wind energy as a clean and renewable energy has attracted more and more attention, it takes a very important position among the alternative energy. Wind turbine gearbox is core components of the wind power generator, because of the poor working condition and long time running, the transmission system will be damnified inevitably, what’s worse it can cause huge economic losses and casualties. In order to avoid the catastrophic accidents caused by the damage gear during operation. So it is necessary that the damage mechanism and vibration isolation be researched.The Prognostics technology has widely used in fault monitoring for various kind of equipment. This technology plays a key role in avoiding accident. But for the wind turbine gearbox, there exist some problems such as the fault mechanics is undefined, run-to-failure data is hard to obtain, incipient damage is difficult to detect etc. So building the dynamic model which has typical damage characteristics, calculation of mesh stiffness and the simulation of the time-varying wind load have a very high engineering value. In order to research the damage characteristics in damage mechanism perspective, the detailed contents and innovative work can be summarized as follows.Combined energy method and the similarity between spur cylindrical gear and helical cylindrical gear, the mesh stiffness of helical cylindrical gear is researched. Then on the basis of this the mesh stiffness of damage gear is given. Then on the basis of this finite element analysis, the effective of gear root crack damage to bending stresses is researched. At the same time, in order to prove the reasonability of model simplifies, the single tooth stiffness that linear crack and curve crack are analyzed with the help of ANSYS software and cantilever beam theory.A wind power dynamics model which considered the influence of multiple factors is established. Combined lumped mass law and Newton’s Second Law to establish bending-torsion-shaft coupled vibration model, time-variable stiffness, damping, support stiffness and other nonlinear factors have been taken into consideration. The dynamics model provided a premise for calculating the dynamic response.Vibration response of healthy gear and root crack damage gear transmission system under constant load and random wind load are solved. Dynamic simulation results is analyzed in time domain, and then obtained the rules between the crack damage characteristics and the system vibration response. This can provide theory basis for early detection of tooth root crack damage. In this last, the relationship between vibration response and magnitude of different crack depth is given. It can be used to predict the depth of crack fatigue.In the last part of this article, dynamics model of the first stage transmission system is built with ADAMS, fully considered of the flexible of sun gear and planet gears, obtained the vibration response of a planet speeder with a crack damage characteristics, verified the theoretical results.