Research On Load Capacity Of Redial-thrust Gas Bearing

Machinery manufacturing industry provides technology and equipment for the entire national economy. Its level of development is one of the main symbol of national industrialization. Modern machinery manufacturing industry, especially aerospace, automobile manufacturing, and abrasive processing industries is developing to high-precision, high speed and high-efficiency. High-precision, high-speed, high-efficiency machine tools put forward higher claim. Spindles with hydrostatic gas bearings have a compact structure, low noise, high mechanical efficiency, small vibration, high accuracy, the smooth operation of electric spindle and no impact. Its service life is longer than ordinary spindle. It is easy to achieve high-speed processing; dynamic static accuracy and stability are very good. It can be stepless within the rated speed range through frequency technology.In this paper, to study the orifice gas radial thrust bearing of the high-speed electric milling spindle, with the application of CFD technology, its distribution characteristics of the flow field and analysis of the bearing capacity are discussed. The main contents include:The flow field distribution and characteristics of the bearing was analyzed on the impact of different numerical models. In the current research on the field characteristics of the gas bearing, radial thrust gas bearings were decomposed into separate radial bearings and thrust bearings. Although this method can simplify modeling and meshing, solvers save time. The gas bearing real working conditions are very different. It can not reflect the true bearing characteristics of flow field. This paper presented a radial thrust joint modeling approach to analyze the differences in modeling and capacity, pressure distribution and other characteristics of the independent modeling by numerical simulation.Comparison of bearing capacity under different working parameters of two modeling methods was analyzed. The capacity characteristics of the radial thrust bearing joint modeling and simulation, the radial bearing independent modeling and simulation and the thrust bearing independent modeling and simulation were compared. The influence and variation of capacity of the radial bearing and thrust bearing were analyzed. Simulation results show that:the radial bearings and thrust bearings flow fields interfere with each other, resulting in the radial capacity of the radial thrust bearing being smaller than one of the radial bearing, the thrust capacity of the radial thrust bearing being bigger than the thrust bearing.The radial thrust gas bearing milling spindle performance test bench was designed and built. Static bearing capacity and processing quality were tested in the experiment at the different rotational speed. Then the experimental results and simulation results were compared and analyzed.