Analysis Of Structural Vibration Characteristics Of High-gravity Centrifuge

With the rapid development of social economy,rotating machinery has also been continuously improved,and centrifuges have also been widely used in engineering applications.Regardless of whether it is the food and pharmaceutical industry or engineering liquid material treatment,higher requirements are placed on the efficient,reliable and long-term smooth operation of the centrifuge.This requires in-depth and detailed rotor dynamics research in the centrifuge design stage.This article mainly studies the following aspects:(1)Based on a domestic industrial high-gravity centrifuge,starting from the structural geometric model,the dynamic calculations such as the modal and harmonic response of the centrifuge are completed.The pre-processing optimization of the model and the constraint relationship of key parts such as ball hinges and springs are mainly introduced.The setting,calculation steps and results of the finite element analysis of the centrifuge are explained in detail,which provides support for subsequent research.(2)According to the ANSYS model,parameter sensitivity analysis is performed on structural parameters such as spring stiffness and damper damping,and the influence of parameters on the critical speed of the system within a reasonable range of values is explored.Under the premise of ensuring the accuracy and validity of the calculation,through the harmonic response module of finite element analysis,the influence of different parameters on the rotor under the same condition is compared and analyzed,and the spring stiffness is obtained in the actual measurement range of the critical speed The effect increases with increasing stiffness.The conclusion that the damper damping value changes within the range of 100-250N*s/mm has a greater impact on the critical speed of the system.(3)On the basis of the supergravity centrifuge model,completed the model design and construction of the vibration monitoring test bench,introduced the test bench key mechanical structure design ideas such as cone sleeve-flange structure and ball hinge lubrication mechanism and test bench Selection and construction of programmable control system.On the premise of ensuring space,an electromagnetic bearing suitable for the rotor of the test bench was designed,and the lower end drum of the centrifuge was replaced with an operable balance disk,which provided a good platform for subsequent experiments.(4)Based on the test bed model,from the purpose of the test bed design,four vibration control models were established respectively,and the flow and condition setting of the analysis calculation were elaborated in detail.Through the control variable method,the four schemes are brought into the analysis layer by layer,and the conclusion is obtained that the rigidity of the ball joint increases the system stiffness,the response amplitude increases,and the electromagnetic actuator and bearing damping can reduce the maximum amplitude.