GSB-11High Speed Centrifugal Pump Rotor System Of The Rotating Shaft Critical Speed Calculation

High speed centrifugal pump is based on a kind of new theory research centrifugal pump, fordelivery of small flow, high lift medium, compared with the common centrifugal pump, it hasadvantages such as compact structure, strong currency, reliable operation, small axial force, longlifetime, plat capacity-head curve, It has been widely used in petrochemical, aerospace,pharmaceutical building fire and other industries. In order to ensure the smooth running of highspeed pump rotor system, avoid the working speed near the critical speed to produce resonanceaffect pump life, in the high speed centrifugal pump designed to accurately calculate the criticalspeed of a rotating shaft of the rotor system. Calculation of the critical speed of rotor system iscommonly used in the finite element method and the transfer matrix method.This paper first introduces the concept of critical speed, vortex theory, under the influence ofgravity under critical speed calculation principle; Derivation of the rotor dynamics classicaldynamical model jeffcott of the dynamic characteristics of the rotor, the differential equations ofmotion; Secondly, the mechanics of materials formulas and Ansys software calculated thestiffness of simply supported beam, and compare the error of less than2percent, to prove theaccuracy of the Ansys software in the calculation for the beam element model, provided aguarantee for the next step of the calculation of high-speed centrifugal pump rotor system in allthe critical speed of a rotating shaft.High speed centrifugal pump gear bearing system is the critical speed of one of the largestcomponents, in the calculation of the critical speed, must first to simplify these models, Thispaper uses the Ansys software for high speed pump rotor system were established gears, bearings,shaft mechanical model, a modal analysis on the intermediate shaft, Calculation of the firstorder, second, third natural frequency, according to the theoretical formula for calculating thenatural frequency, using the stochastic vibration method for measuring shaft rotor systeminherent frequency, to compare the size of the error. Finally, use Ansys software rotor dynamicscalculations on undamped multi-disc rotor, elastic support the damping asymmetric rotor and thehigh speed shaft, Draw the high speed shaft Campbell figure and have high speed shaft criticalspeed.Due to the complexity of the system, the model of different simplified process, the selectionof boundary and so on, Ansys software calculation and experimental test of the critical speed mayhave some error, but according to the results obtained by the software calculated andexperimental, we can predict the rotor resonance speed range, avoid working rate appears in thevicinity of the critical speed, this will reduce the design cost, the project has a certain practicalvalue.