Dynamic Stiffness Analysis Of Rolling Bearing Based On Multi Parameter Coupling

High speed rolling bearing is the key component of high speed motorized spindle,modern aviation turbine engine and locomotive.The critical speed,vibration characteristics,reliability analysis,noise and fault detection and diagnosis of the bearing rotor system depend on the dynamic stiffness of the bearing.Therefore,it is necessary to study the dynamic stiffness of rolling bearings.The stiffness of the rolling bearing is formed by the contact stiffness between the rolling body and the ring and the oil film stiffness.This paper considers the shaft and the ring centrifugal deformation,thermal deformation,elastohydrodynamic lubrication,speed and other factors,the establishment of the angular contact ball bearing quasi static correction model,calculate the bearing is closer to the actual operation of the process of dynamic stiffness;it establishes the analysis model of oil film roller bearing multi parameter coupling stiffness under the load.Lubricating oil,entrainment speed,viscosity,surface morphology of oil film stiffness.The main contents of this paper include:(1)The contact stiffness model of angular contact ball bearing considering the influence of multi factors is established.Calculate the meter centrifugal deformation,thermal deformation and no centrifugal deformation and thermal deformation of two kinds of models of rolling bearing dynamic stiffness,draws the following conclusion: all increases with the increase of rotational speed and shaft deformation of inner ring centrifugal deformation and radial and axial thermal deformation,and the inner ring centrifugal volume was significantly higher than the centrifugal shaft deformation,significantly greater than the axial thermal deformation of radial thermal deformation;speed on the influence of inner ring centrifugal deformation and radial thermal deformation is obviously higher than that of axial centrifugal deformation and axial thermal deformation;influence of rotational speed on the radial stiffness,axial stiffness and angular stiffness of the minimum;radial,axial and angular stiffness decreases with increasing speed;considering the centrifugal ring deformation and thermal deformation,a great influence on the radial stiffness has little effect on the axial stiffness and angular stiffness.(2)The calculation model of the dynamic stiffness of angular contact ball bearing is presented.Analysis shows that,with increased speed,the minimum oil film thickness increases;the inner film thickness increases,the inner oil film stiffness decreases,but the outer oil film thickness increase makes the outer oil film stiffness decreased first and then increased;with the increased speed,radial elastohydrodynamic lubrication effect on the radial stiffness is more and more obvious and less than.The elastohydrodynamic lubrication EHLmakes stiffness,axial stiffness and angular stiffness decreased in varying degrees,the elastohydrodynamic lubrication of axial stiffness and angular stiffness of shadow ring is significantly less than the radial stiffness.(3)The rolling bearing oil film stiffness model based on multiparameter coupling is established in this article,which takes into account the non-Newton fluid elasto-hydrodynamic lubrication theory,rough surface morphology,thermal effect,time-dependent effect and other factor.The change rules of oil film pressure,film thickness,temperature,and the oil film stiffness in the complete cycle are obtained by numerical calculation.The results show that the oil film stiffness is nonlinear in a cycle,increase with increasing load,viscosity,amplitude of surface roughness,and decreases with increasing entrainment velocity.The oscillation frequency of oil film stiffness increase with increasing wavelength of surface roughness,the angle between texture direction of rough surface and direction of bearing rolling.When the bearing running,the temperature rise of oil film is the largest,the temperature rise of inner ring is second,and rolling body is minimum but should not be neglected.