Dynamic Performance And Active Control Research On The Flexure Pivot Tilting Pad Hybrid Bearing

Tilting bearing because of its excellent stability is widely used in large rotating machinery.Compared with traditional telescopic sliding bearing,the biggest advantage of tilting tile bearing is its excellent stability.But tilting tile bearing has disadvantages,such as complicated structure,processing and assembling requirement is high,the fulcrum is easy to wear,easy to form the error accumulation,the bearing shell chatter caused by faults.Flexible hinge tilting tile bearing has not only ordinary tilting tile bearing stability,but also overcome the ordinary tilting tile bearing the above disadvantages.Hybrid bearing has advantages of static pressure and dynamic pressure bearing,such as large carrying capacity,oil film rigidity is high,reliable operation,less energy consumption of oil.So it attracts widespread attention at home and abroad.But the effect of application in the production practice shows that there are some problems of hybrid bearing.Some scholars tried to combine tilting bearing and hybrid bearing together,so that it is both advantages.But in these studies the bearing is not using the flexible hinge structure,there are still some problems,such as complicated structure,processing and assembling requirement is high.According to the above problems,this paper on the basis of the flexible hinge tilting tile bearing processing the static pressure chamber,processing oil hole in the flexible hinge,thus simplify the pivot structure,overcomes the disadvantages of the common support structure.This article Research on several aspects,such as the bearing structure design,the bearing static characteristic analysis,the journal centre trajectory under the load and active control of the Journal centre vibration,and provides theoretical guiding significance to the engineering application of this kind of new type tilting tile bearing.Concrete research content is as follows:First,make an introduction the structure design of the bearing,design the Oil supply way By establishing the calculation model of flexure pivot tilting pad hybrid journal bearing,gives the expression of oil film thickness and Reynolds equation.Using the finite difference method and SOR to solve the Reynolds equation,combined with Newton iterative method to calculate the bearing static performance.Compared the change of load coefficient,flow coefficient,friction coefficient and power consumption under different eccentricity,rotation speed and the cavity dimensions of the static pressure oil.Get the static performance parameters of the bearing under certain conditions.Second,the non-linear analysis model of journal centre trajectory is establish,Using the Euler method to calculate the nonlinear journal centre trajectories and Bush oscillating displacement under the dynamic load under.Analyze the transient characteristics of nonlinear journal centre trajectories under the step load and rectangular pulse load and triangular pulse load.Comparative and analysis the influence of different load on the main parameters.Finally,made active control to the Journal centre vibration as the Journal under the dynamic load.Control the motion of bearing shell actively,change the oil film pressure to control the Journal centre vibration.Two control methods are given,that is,open loop control method and the closed loop control method.And made a comparison of the two kinds of method.The calculation results show that both methods are efficacious.