Research On The Stability Of Wire-cut Integrated Bearing

With the improvement of wire cutting technology,wire cutting integrated bearings with higher precision and better stability have appeared.The wire-cut integrated bearing directly connects the bearing seat and the bearing bush through a flexible hinge,which reduces the error caused by assembly;the flexible hinge support is used to replace the rigid support of the traditional tilting pad bearing,which eliminates high contact stress and wear and reduces the Bearing deformation.This thesis takes the wire-cut integrated bearing as the research object,establishes the lubrication control equation and rotor motion equation of the wire-cut integrated bearing,and studies the stability of the wire-cut integrated bearing system.The main research contents are as follows:(1)Establish the physical model and mathematical model of the wire-cut integrated bearing.The discrete Reynolds equation and the energy equation are solved by the finite difference method and the over-relaxation iterative method,and the bearing pad swing angle at the equilibrium position is solved by the Newton iteration method,and the oil film pressure field and temperature field of the bearing are calculated.When the journal and the bearing bush are disturbed at the same frequency,the calculation methods of eight dynamic characteristic coefficients of the wire-cut integrated bearing are given.At different speeds,the static and dynamic characteristics of the wire-cut integrated bearing with the width-diameter ratio,eccentricity and clearance ratio were studied.(2)Compare the static and dynamic characteristics of the wire-cut integrated bearing between the pads and the pad,large and small wrap angles,flexible fulcrum support and rigid fulcrum support,and four-tile and five-tile bearings at different speeds.The conclusion is drawn: the stability of the bearing between the pads is better than that of the bearing on the surface of the pad;the static performance of the small angular bearing is better than that of the large angular bearing,but the stability and the ability of suppressing the resonance peak of the large angular bearing are better than those of the small angular bearing;the bearing flexible fulcrum The dynamic and static characteristics of the support are better than those of the rigid fulcrum support;the multi-valve bearing has better lubrication performance,but poor dynamic performance.At the same time,the influence of bearing bush offset ratio,preload and bearing bush self-excited vibration frequency ratio on bearing stability at different speeds is analyzed.(3)The mathematical model of the rigid rotor system supported by the wire-cut integrated bearing is established,and the Euler method is used to solve the nonlinear axis trajectory,analyze the oscillation law of the wire-cut bearing bush,and study the journal rotational speed,rotor quality,unevenness Influence of gauge and aspect ratio on bearing-rotor system stability.