Study On Axial Trajectory Of Hydrostatic Bearing-shaft System With Capillary Throttle

Hydrostatic bearings are getting popularity in rotating machinery due to ability of supporting heavy load,high-precision,high rotation accuracy and high speed.The working conditions can be controlled by the axial trajectory of the journal in hydrostatic bearing.It can directly determine the stability of the bearing,knowing the bearing lubrication condition,verifying the rationality of the bearing designing parameter through the axis trajectory.Therefore,it is very important to study the influence of bearing system parameters under the static load or dynamic load on the axial trajectory.This Thesis presents the four-chamber hydrostatic bearing with capillary throttling as the research objective to establish a fluid lubrication equation and simultaneous flow continuity equation.It can solve bearing’s pressure and bearing capacity of oil film.The dynamic equation of hydrostatic bearing is established.So it establish hydrostatic bearing axis trajectory solution model.On the basis of the model of the hydrostatic bearing axis trajectory,the parameters of the bearing system can be divided into three classes such as;bearing structure parameters,operating parameters and capillary parameters.The influence of the parameters of the bearing system on the motion of the axial trajectory is analyzed by one-way variable method.Then,by using the law of conservation of mass to solve the hydrostatic bearing oil chamber pressure with ignoring its dynamic pressure effect,to make oil chamber pressure linearized.The dynamic equation of hydrostatic bearing is established.The linear pressure of the oil chamber is simultaneous,it pull the two type to Laplace transformation.It build the dynamic response control block diagram of the spindle center relative to the external dynamic load.Based on this control block diagram,It set step load,pulse load,ramp load and sine wave load as the external load.Adopting the method of single factor variable do research of dynamic response characteristics of the axial trajectory under the dynamic load.Finally,it set up oil film bearing test stand and do experiment of capillary restrictor hydrostatic bearing axis trajectory.As a result of the limitation of experimental conditions,the measured data contains noise interference.After obtaining the measurement data,it do purification of the axis trajectory and get clear axis trajectory.The result shows that the parameters of the bearing system have an important influence on the law of the axis trajectory.This will provide some theoretical support for the future bearing design work.