Research On The Water Lubricated High Speed And High Accuracy Main Shaft

With the development of science and technology, the mechanical manufacturing technology is stridden forward all in the high speed, low consumption, high quality and high accuracy. Nowadays the prevalent forms of the high speed main shaft are high speed motorized spindle, high speed gas main shaft and high speed magnetic main shaft. For limitations of these main shafts, it is necessary to design a new-type high speed main shaft while reducing the cost of key technology and breaking the limitation of those main shafts.A new-type high speed and high accuracy main shaft supported by water lubricated technology is introduced in this text. Considering the finished works in the laboratory and actual conditions, the focal point of study is placed on the global design of the main shaft system, numerical method of water-lubricated ceramic sliding bearing and simulation study of the main shaft.The global design of the main shaft system is finished. The high speed conversion electrical motor is selected as power input. The high speed large angle belt and unloading belt wheel is adopted. The hybrid sliding bearings are made of ceramic and the anti-friction material is water added additive. The material selection and preliminary structural design of the main shaft are finished.The program of the journal bearing and thrust bearing adopts finite difference method. Synthesizing different performance indexes, such as load-carrying ability, rigidity, friction power and etc, 6 cavities bearing is selected as journal bearing and 4 cavities flat bearings is selected as thrust bearing. The structural designs of bearings and restrictors are finished.The static analysis and modal analysis are applied in main shaft by using the finite element software ANSYS. After static analysis the offset variable, intensity and rigidity of the main shaft are gained; after modal analysis the natural frequency and critical speed of the main shaft are gained.