| As environmental issues have been one of the crucial global challenges, especially for the last decades as more evidences on the aggravation of energy shortages have been reported, seeking to sustainable development and turning sight to the renewable energies are the inevitable choices of human society. Recognizing that the wind is one of the most pollution-free, abundant and economical sources of renewable energies, international organizations and governments allocate plenty of money for promoting the research of renewable energy, the worldwide growth of renewable energy generation has fostered a rapid expansion of wind farm. The annual installations of wind turbine generator system having been grew increasingly recent years.Coupling, as a significant part of wind turbine generator, is used to connect gearbox high-speed shaft and generator drive shaft and plays a pivotal role in electricity generation. The main task of coupling is to transmit torque, in addition, it also performs other effects on occasion, e.g., reducing system vibration and impact loads, taking precaution against overload, compensating for shaft, radial and angular offset and linking or separating the shaft ends.In the present paper, the main objects are as follows:(1)In chapter 1, the background and significance of this research are introduced. The advantages and disadvantages of wind power, the research status quo and development tendency of coupling in domestic and overseas are presented, then, the summary of research situation is illustrated.(2)Chapter 2 describes the classification and function of coupling, and MW wind energy converter coupling is taken as the object of study, the basis features of the analysis and design are investigated by theoretical analysis and numerical simulation. In addition, the whole geometric model of the coupling is assembled by Pro/E software, and for the simulation of its structure response, the finite element model is established and the structure response is analyzed.(3)Tension, pressure and centrifugal force that the diaphragm subjected to are analyzed in chapter 3, thus, the buckling safety factor is calculated. And the buckling destination may occur to diaphragm, to optimize the size of the diaphragm so that it can achieve the request under maximum torque is necessary. Beside, the fatigue endurance of diaphragm is presented as well. By calculating the force condition of diaphragm under prescribed load conditions and considering wind turbine generators are always located in unpredicted situation over 20 years, the fatigue endurance can be verified if it satisfies the requirement.(4)In chapter 4, the natural frequencies of coupling under free status and restrained status are calculated and if resonance will occur to diaphragm when it under service speed and maximum speed is inspected. Besides, this chapter analyzes the stiffness of coupling and calculates axial tension and compression stiffness, bending stiffness and torsional stiffness in all directions.(5)The bolts preloading force between end cap and taper sleeve2 and the bolts preloading force between keyless coupling and motor shaft at installation time are discussed respectively in chapter 5. Due to coupling has to sufficient to non-slip demand, bolts preloading force should be confirmed reasonably to make sure that the slip torque under different bolts preloading forces all satisfies design slip torque.(6)The main work in this chapter is the investigation of mechanical properties of composite material fiber tube affected by hygrothermal environment in the condition of pure torsion. Firstly, the deformation formula of composite material fiber tube with the action of torque, which is based on constitutive equation of single layer material under hygrothermal environment, is deduced. Then the influences of humidity, temperature, fiber orientation and relevant parameter on deformation are analyzed. Finally, numerical examples are presented to compare with the above figures and the correctness will be verified. |
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