Research On Performance Of High-speed Hydrodynamic And Hydrostatic Mixed Lubrication Thrust Bearing

Hydrodynamic and hydrostatic bearing is a kind of oil film bearing which has the advantages of dynamic pressure bearing and hydrostatic bearing, its hybrid bearing capacit with hydrodynamic effect and static pressure. But large vertical CNC processing equipment work under the extreme conditions such as high speed, heavy duty and micro clearance, the clearance oil film temperature of hydrostatic thrust bearing rise sharply, lubricating oil viscosity decline sharply, oil film grow thin quickly, local bearing friction pair appear boundary lubrication or dry friction, and then happen tribology failure. Therefore, proposed to dynamic and static pressure oil pad instead of static pressure oil pad, make it a dynamic and static pressure bearing, solve this problem.In this paper, the sector dynamic and static pressure oil pad as the research object, to explore the performance of high-speed hydrodynamic and hydrostatic mixed lubrication thrust bearing. Using UG three-dimensional modeling software set up oil film mode for one-way hydrodynamic-hydrostatic oil pad oil film and bothway hydrodynamic-hydrostatic oil pad oil film; then the geometric model is meshed by using ANSYS ICEM CFD software, setting the boundary parameters of oil film model. First, determine of dynamic and static pressure oil pad structure size, in order to make the optimal effect of dynamic pressure, considering the influence of the dynamic pressure wedge length and height, using ANSYS CFX software analysis the change situation of different wedge length and height in dynamic and static pressure oil pad oil film at pressure field, temperature field and velocity field under the same speed and load conditions, and analysis results are compared, get the optimal size of wedge length and height in the dynamic and static pressure oil pad. Then using ANSYS CFX software analysis the change rule of the above two kinds of dynamic and static pressure oil pad oil film at pressure field, temperature field and velocity field under the different speed and load conditions, and analysis results are compared, revelation the influence of rotating speed and load on the lubrication performance.In order to verify the correctness of the theoretical calculation and simulation analysis, the experiment of Q1-205 vertical CNC lathe in Qiqihar Heavy CNC Co., Ltd. Actual measurement oil film temperature data of dynamic and static pressure oil pad under the same load different rotational speed, analyse the relationship between rotating speed and temperature; and the oil film temperature data in the different location, variety of oil film temperature around dynamic and static pressure oil pad in different positions is analyzed, the correctness of the theoretical analysis and simulation results are verified.