基于CFD的数控六面铣床电主轴支撑设计及承载特性分析

Support Design and Bearing Characteristics Analysis of Electric Spindle of CNC Six-Sided Milling Machine Based on CFD

摘要: 为了获得高速电主轴的有效支撑，提高高速数控铣床的性能，以数控六面铣床电主轴为研究对象，设计了狭缝节流气体静压半球轴承。基于CFD (Computational Fluid Dynamics)理论，分析了不同偏心率、不同供气压力和不同主轴转速下的轴承承载特性。研究发现，轴承承载力随偏心率、供气压力和主轴转速的增加而提高。刚度随偏心率的增大而减小，随供气压力和主轴转速的增加而增大。低供气压力下偏心率对轴承刚度的影响较小，高供气压力下偏心率对轴承刚度影响较大，且高偏心率下轴承的刚度随转速提升的幅度较大。

Abstract: In order to obtain the effective support of high-speed motorized spindle and improve the performance of high-speed CNC machine tool, taking the motorized spindle of CNC six-sided machine tool as the research object, an aerostatic hemispherical bearing with slotted current limiter is designed. Based on CFD theory, the bearing capacity characteristics of different eccentricity, different supply pressure and different spindle speed are analyzed. It is found that the bearing capacity of the bearing increases with the increase of eccentricity, supply pressure and spindle speed. The stiffness decreases with the increase of eccentricity and increases with the increase of supply pressure and spindle speed. The eccentricity has little effect on the bearing stiffness at low air supply pressure, but has a great influence on the bearing stiffness at high air supply pressure, and the bearing stiffness increases greatly with the increase of rotational speed at high eccentricity.