Research On Reasonable Matching Relationship Between Dynamic And Static Pressure Of High-speed And Heavy-load Hydrostatic Thrust Bearing

In extreme working conditions of hydrostatic thrust bearing,because the speed and load are larger,the oil film temperature improv es rapidly and the hydraulic oil viscosity decreases rapidly and oil film becomes thickness.Static pressure loss occurs,the movement side cannot be located in the liquid friction state and if keeping in the state for a long time,there will be friction failure.In order to achieve the purpose of compensating the static pressure bearing capacity,wedge is arranged at one side of double rectangular cavity under the condition that the oil inlet can work normally.By using the dynamic pressure produced by the wedge effect to compensate for the static pressure loss,we can ensure that the oil film thickness does not change.When the flow compensation loss of hydrostatic pressure average value is equal to the dynamic pressure effect of average pressure values,the reasonable matching relationship of reach hydrostatic bearing dynamic static pressure can be achieved.Two types of oil film of double rectangular recess hydrostatic oil pad and double rectangular recess hydrodynamic-hydrostatic oil pad is taken as an example in this thesis and the matching relationship between static pressure and dynamic pressure is researched.Under the condition of constant load 10 t,first the geometry parameters and the boundary conditions of shaped cavity are identified,then the flow static pressure loss is calculated theoretically and 3D models of double rectangular recess hydrostatic oil pad oil film and double rectangular recess hydrodynamic-hydrostatic oil pad oil film are established by UG software.Second,the grid of these physical models is meshed by ANSYS ICEM CFD.At last,the pressure field and temperature field of oil film are simulated with same load and different speed and wedge angle.The average pressure values of the cavity are obtained with different speed and wedge length.The pressure field and temperature field of hydrostatic oil pad oil film without wedge are analyzed after the flow is compensated.Then the average pressure values of different cavities are obtained and the values of two kinds of oil pad oil film are compared.Only the average pressure value is the same,dynamic pressure effect can compensate the hydrostatic pressure loss with this wedge length.During the limited length that does not affect the normal work of the oil mouth,the length parameters are obtained and the increasement of double rectangular dynamic and static pressure oil pad can compensate the hydrostatic pressure loss,and then the reasonable matching of dynamic and static pressure can be realized.The experiment is conducted with 5m hydrostatic workbench in Qiqihar Heavy CNC Co.,Ltd.Research Laboratory.The thickness of static pressure pad oil film,temperature and pressure are tested and recorded and the law that o il film thickness,temperature and oil film pressure change with speed is obtained.Then the temperature values of different positions is measured and recorded with the speed 10t-140r/min and the temperature trend of double rectangular oil pad is summarized.By this experiment,we can certify the accuracy of the theory and simulation.