Simulation of thermal characteristics of high speed spindle considering air gap variation
LI Te,Rui Zhi yuan,LEI Chun li,GUO Jun feng,HU Chi bing
1. Key Laboratory of Digital Manufacturing Technology and Application,The Ministry of Education.
Lanzhou University of Technolagy,Lanzhou 730050,China；
2.College of MechanoElectronic Engineering,Lanzhou University of Technology, Lanzhou 730050,China
A viewpoint on the centrifugal expansion and thermal expansion which would affect the convection heat transfer between stator and rotor of high speed spindle was proposed to solve the problem that the thermal characteristics caused by structure variation of high speed spindle would be changed under high rotation speed. Based on the theory of elastic mechanics, radical expansion and air gap changes which caused by the radical expansion were calculated considering the two expansions acting on the stator and rotor of spindle. Variation rules of air gap and convection heat transfer coefficient that affected by the centrifugal force were obtained according to the convection heat transfer theory. The calculation results show that the air gap length decreases with the expansion of the rotor, and the reduction is 377% of the design value. The Taylor number increases with the increase of the rotating speed, while decreases with the increase of the air gap length. The heat transfer coefficient of air gap decreases with the increase of air gap length, so that the heat transfer between the stator and rotor is restrained. Results show that the temperature rises and thermal displacement can be significantly reduced if the convection heat transfer coefficient and the cooling power can be properly promoted, then the machining accuracy can be improved．
LI Te,Rui Zhi yuan,LEI Chun li,GUO Jun feng,HU Chi bing. Simulation of thermal characteristics of high speed spindle considering air gap variation. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2016, 50(5): 941-948.
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