重力和离心力耦合作用下高速轴径向变形分析

Analysis on Radial Deflection of High-Speed Shaft under Gravitational and Centrifugal Force

跨距较长的轴在自身载荷作用下产生较大的挠度,进而导致轴高速旋转时离心力沿中线分布不均匀,从而加大了轴的挠度.在重力和离心力耦合作用下,轴端翘起导致轴端与密封件的磨损严重.本文提出了一种利用有限元分析模拟重力和离心力耦合作用下高速轴径向变形的方法,并将其应用于高速轴的设计中.结果表明,在2000 r/min的额定转速下,轴端的径向变形量达到64μm.通过优化轴承的位置,使轴端的径向变形量下降为1.8μm,有效的降低了密封件的磨损.最后,利用模态分析,发现改进设计后轴的额定转速有效的避开了其各阶临界转速.

Deflection of a long span high-speed shaft was caused by gravitational force, which generated non-uniform distributed centrifugal force along the axial direction. The non-uniform distributed centrifugal force increased the shaft deflection. Abrasion between shaft ends and sealed parts occurred due to the radial deflection induced by gravitational and centrifugal force. In this study, a method was presented to estimate the radial dei/ection of shaft ends under gravitational and centrifugal force using finite element analysis. It was used in the application of the design of high-speed shaft. The results showed that the radial deflection of shaft end is 64μm when rotational speed reaches to 2000 r/min. After optimizing the position of bearing, radial deflection of shaft end dropped to 1.8 μm, which could effectively reduce the abrasion of sealed parts and shaft ends. Finally, it was also found that the rated speed of shaft is much smaller than the calculated critical speed.