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Study On Stability Of Fluid Dynamic Lubricates And Bearing Rotor System

Posted on:2007-06-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:J F YangFull Text:PDF
GTID:1102360182983009Subject:Thermal Engineering
Abstract/Summary:PDF Full Text Request
This thesis works over the radial sliding bearing fluidsolid coupling motion mechanism and thestability issue of rotor system based on fluid dynamic lubricates theory. Based on the structuralanalysis of Reynolds equation and approximate analytic solution,the thesis focuses on the structuralcharacter and application conditions of sliding bearing dynamic oil film force, specifically analysesand studies the coupling relations among relevant structure, movement state and movement action,and raises some new research theories and methods. The application of these theories and methodscan efficiently resolves the practical project problems of bearing lubrication and stability in bearingrotor system, as well as points out clearly the development direction of further analysis and study inthis field.For the first time puts forward a kind of estimation criteria of stability analysis of sliding bearingrotor system and a new technology of coupling frequency modulation, advances the analysis methodof swirl coupling excitation and nonlinear coupling vibration displacement limit cycle, illustrates theinternal relation between nonlinear dynamic oil film force function and bearing instabilitymechanization. With the analysis and study of low frequency swirl and oil film vibration of bearingrotor system, further illustrates the correctness and practicability of this technology which is also wellvalidated through numerical value simulation calculation of 200MW steam turbine low voltagebearing rotor system, single span,twin spans bearing rotor system test and 100KW minimize gasturbine vibrating malfunction treatment.Based on the resolution model of bearing fluidsolid coupling dynamic oil film force and theresolution analysis of single span single disk bearing rotor system, for the first time brings forward thedynamic expression of system "equivalent firmness" and bearing oil film damp, as well as therelationship between oil film dynamic character quotient and oil film damp quotient. Based on themodel test analysis of single and twin spans bearing rotor system, further illustrates the theory ofemergence of bearing rotor system fluidsolid coupling effect, oil film swirl state and vibrationaction, interaction results of rotor movement and action of different bearings, especially during thestartup and stop process of bearing rotor system, shows clearly the oil film vibration slowmovingphenomenon of oil film vibration startup and stop, and changing process in zooming in and zoomingout of fork fig and 3D axes locus。According to the nonlinearity dynamic sliding theory of hydroboundary layer and with theresolution solve of Reynolds equation, comes up with the common dynamic oil film force analyticsolution of style radial sliding bearing and expression of corresponding лoil film force decomposition.Besides, with equation analysis of dynamic border, puts forward the analytic solution of dynamicborder equation meeting the maximum voltage border condition (), which resolves theborder analysis and calculation problem of dynamic oil film force.Through compurgation and analysis of several typical radial sliding bearing dynamic oil filmforce analytic model, further demonstrates the difference, links and relevant appropriate conditions ofvarious models. At the same time, with the analysis of swirl frequency equation of finitudelengthradial sliding bearing dynamic oil film and bearing fluidsolid coupling movement, further illustratesthe character of axial diameter halfspeed swirl, and puts forward some nonlinearity characters ofaxis liquidsolid coupling swirl state and action.
Keywords/Search Tags:axis rotor system, nonlinearity dynamic oil film force, stability estimation, coupling frequency modulation technology, rotor dynamics
PDF Full Text Request
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