| In recent years, the manufacturing industry of off-grid small wind driven generator becomes prosperous again. According to statistics, for many new production units, the unit capacity is more than 1KW, and increasing. With the increase of the unit capacity, its weight of the unit and the forces on its components have been increased inevitably. However, current research on the KW unit is mainly focused on high-efficiency motor, but there is only few research on structural reliability. By means of finite element software ANSYS, the author studied key components of its main shaft and base for 5KW off-grid small wind drive generator which is developed by China Changjiang National Shipping Group Motor Factory.The main working contents include following items:1. Through the analysis of off-grid small unit about its development and research as well as current problems in the situation both at home and abroad, its reliability study is very important particularly for our country.2. Through experiments and derivation, the load on main shaft in ultimate rotate speed is calculated. According to simplified the main shaft, the finite element model of the main shaft is established by means of its comparison and trend analysis. When the model is loaded, it is found that many common torque loading methods are not suitable. The author uses the new load method, the analysis results are reliable, its strength is sufficient at the limit speed of the main shaft. By setting the path and extract particular values on a path, it also discovered that the deflection of rotor shaft is in allowable range when the main shaft at ultimate rotate speed.3. The model analysis of the main shaft is carried out respectively when it is without load and with ultimate load, the reason why two results are different is deduced. And the deduction is examined. Finally the natural frequencies range of the main shaft is obtained at speed limit, it is found that the main shaft has no risk to vibrat when it worked at designed rotate speed.4. By setting the path and extracting specific values, the dangerous points on the main shaft are found out, the fatigue failure is existed at these points, and the stress changing regularity of the dangerous points is obtained. By fatigue analysis of the dangerous points, it is tested that the main shaft can meet designed fatigue life. 5.The base is simplified, and its finite element model is established. By ultimate load analysis of the base, the results show that the base can meet strength requirements and stand ultimate load.6.By means of the same method, the natural frequency range of the base is analysed, and it is found that the base has a risk of vibration at the natural frequency when the main shaft is working in limited speed range. The solution method is presented by the author here.Through these efforts, the unit reliability can be pre-authenticated, possible problems also be found, further improvements be proposed, and thus the quality unit be improved. On the other hand, these efforts can partly take place loading and fatigue trail of the generator, shorten the development cycle, decrease R&D cost.These research results have been used in new improvements of the machine and will play a practical role. |
PDF Full Text Request