Load Sharing Analysis Of The Planetary Gear Stage In A Wind Turbine Gearbox With Flexible Pins

The research subject of the dissertation stems from the projects “The study of Key technologies of industrialization for 7MW wind turbine gearbox and spindle bearing”(2012BAA01B05) in the National Science and Technology Pillar Program during the12 th Five-Year Plan period of China, respectively.Gearbox is an important part of a wind power generator. It turns the input from the blades which is a large torque with low rotational speed to an output which is a small torque with high rotational speed to make the generator cheaper and easier to produce and in this way saves the cost of the whole wind turbine. With the development of wind turbine technology, the size and power capacity of a single wind power generator will become larger and larger, and planetary gear sets will be used widely in future large power wind turbine generators because of their big advantage that they have large power capacity compared with parallel gear sets.Load sharing charactristic is very important for planetary gear sets and almost all the advantages planetary gear sets have over parallel gear sets are based on good load sharing situations. Flexible pins reduce the bearing stiffness of planet gears so the planets can float automatically to compensate for the position errors caused by various reasons and in this way they can improve the load sharing situation of planetary gear sets. So flexible pins may have a bright future in future large power wind turbines. This article will do research on the effects of flexible pins in planetary gear sets.The main contents of this article will be:① Introduce the development and future of wind turbine technology, make some descriptions of the structure and development of wind turbine gearboxes. The necessity of the article is given, and the structure of flexible pins are introduced and some works about wind turbine gearboxes, flexible pins and load sharing of planetary gear sets are discussed.② The structure and transmission principle of the wind turbine gearbox with flexible pins are introduced, the structure and working principle of flexible pins are discussed. The FE model of a 1.5MW wind turbine gearbox with flexible pins is established and a static analysis are done based on the model.③ Do some research about the load sharing charactristic of the planetary gear set based on FE method, the effects of errors, input torque and flexible pins on load sharing are studied. The variation of load sharing when multiple errors act together is discussed.④ To analysis the load sharing charactristic of the planetary gear stage while gearbox working in reality, an equivalent load case are specified which contains all the possible changes of input torque caused by various reasons, such as the change of input torque when turning up/down the wind turbine, and the fluctuations of the input torque caused by other reasons. The load sharing charactristics of the planetary gear stage in the gearbox in all the cases are analyzed based on the equivalent load case, and the effects of flexible pins on load sharing in these cases are also discussed.⑤ The online test system of load sharing of the planetary gear stage in the gearbox is found, and the load sharing charactristics are tested based on stress-strain method.