RESEARCH ON CRITICAL SPEED AND DYNAMIC STABILITY OF CENTRIFUGE BASED ON ROTOR DYNAMICS

摘要

Centrifuge is wildly used in civil engineering and environment experiments et al. The power system drives the rotor shaft and arms to produce centrifugal field for experiments, it is a typical rotor system. Some previous work has focused on modal frequency to investigate the dynamic characteristics of centrifuge, and estimated the structural design by strength instead of stability. With the increased requirement for higher load and faster rotational speed, the gyroscopic effect of spinning could not be ignored. This work develops the analysis approach of rotor dynamics for typical centrifuge with arms, based on considering the gyroscopic effect and the principle of rotor dynamics. Also, the stress strengthen effect induced by the high centrifugal force has been considered. Next, a typical centrifuge is modeled by the above approach and its critical speed is studied. The state of unbalance force is also analyzed and the dynamic stability of the centrifuge is assessed according to the standards of rotor machines. The assessment method for dynamic stability of centrifuge is established by deformation of the shaft instead of the stresses. The numerical method is verified by dynamic test results on an operating centrifuge. The study supplies reference for this class of rotor systems.