| With the increasing pollution of the environment and the gradual decrease of non renewable resources,the development and utilization of clean and renewable resources have attracted wide attention all over the world.At present,the most developed clean and renewable resources are mainly wind energy.The most effective way to utilize wind power is to generate electricity by using wind turbines.Although the mature and the most widely used wind turbine is the form of single wind wheel,the double wind turbine has higher wind energy capture rate,and the utilization rate of the resource is higher.Therefore,the double wind turbine and its technology have attracted more and more attention.In order to achieve the purpose of lightening the weight of the top engine room of the double wind turbine,a new double wind wheel wind power generator drive system is designed.Considering that the spiral bevel gear geometric size is smaller for the same load capacity,it is selected as the main part of synthetic speed increasing drive system.In order to analyze the operation characteristics of synthetic speed increasing transmission system,its dynamic characteristics need to be studied.The main contents of this thesis are as follows:(1)The transmission scheme of the transmission system and the geometric size of the gear pair are designed.In reference to the design requirements of the generator,a new type of wind turbine drive system is designed,and two pairs of spiral bevel gears are selected as the gear pairs in the synthetic speed drive system.According to the related theory of mechanical design and the method of strength checking,the calculation of the main geometric parameters of spiral bevel gear is completed,and the structure schematic diagram of the transmission system and the three-dimensional solid model diagram are drawn;(2)The dynamic model of the transmission system is set up.The central mass discrete method is used to simplify the gear and input and output shaft parts to disc rotor.The stiffness and damping of the new double wind turbine generator are simulated by spring and damper,and a seven degree of freedom pure torsional vibration model of the new type double wind turbine generator is established.By using Newton's law of motion(Darren Bell's principle),the differential equation of the dynamic model is derived and its matrix form is obtained;(3)The specific values of each parameter in the dynamic model are calculated.The rotary inertia of gear pair and shaft section is obtained by using Solid Works software.By using the principle of total moment of inertia and invariable total mass center,the moment of inertia of each mass element in the dynamic model of transmission system is obtained.The discrete meshing stiffness of two pairs of spiral bevel gears in two meshing cycles is obtained by using the ABAQUS software,and the fitting calculation is carried out,and the meshing comprehensive stiffness value of the gear pair is obtained.According to the theory of material mechanics and the existing formula,the torsional stiffness and other damping parameters of the shaft are calculated;(4)The dynamic equations are solved and the results are analyzed and compared.According to the characteristics and requirements of the numerical calculation,the system dynamics equation is normalized,and the Runge Kutta numerical integration method and the ODE45 function in the Matlab software are used to solve the equation,and the solution results are analyzed and compared. |
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