The Study On Flow Characteristics And Carrying Capacity Of Oil Cavity In Hydrostatic Turntable

The increasingly development of technological drives the development ofaerospace technology, shipbuilding industry, automobile industry and weaponsmanufacturing, which are taking higher manufacturing requirements to the machinetools. With the great carrying performance, low frictional resistance, long service life,high aseismic behavior, high precision and well stability, hydrostatic support systemhas become the core component in high-precision CNC machine tools. Theinvestigations of carrying ability in the hydrostatic turntable system will not onlydirectly affect the reliability of operation, life and economic indicators, but also havegreat effects on the technology progress of CNC machine tools.This paper studies hydrostatic turntable oil cavity's flow field characteristic andanalyzes oil cavity's stability and carrying capacity with different factors based onexperiment, numerical simulation and theoretical method.(1)The oil cavity's flow field comparing with numerical simulation ones whenthe fluid is water and analyzing carrying capacity were studied. Experimental resultsshow that when the inlet Reynolds number increasing, the vortex amount does notchange and the vortex moves toward oil sealing. The curves of vortex position varywith inlet Reynolds number show that vortex moved slower with the inlet Reynoldsnumber increasing. Vorticity map of experiment results indicate that partial flow fieldis complex. Numerical simulations for the upper wall stress distribution and shearingstress distribution showed that the upper wall pressure show constant except the inletjet area, wall slip may appear on the inlet jet with max shearing stress.(2)The changes of flow field and carrying capacity with several factors werestudied. By analyzing the oil cavity's flow field, velocity distribution and wallpressure with different lubricant viscosity, inlet flow, oil sealing gap, wall rotation andwall slip, it is indicated that increasing lubricant viscosity and oil sealing gap affect oilcavity's stability little which are opposite to inlet flow and wall rotation increasing,while increasing lubricant viscosity and inlet flow could enhance the carrying capacitywhich are opposite to oil sealing gap and wall rotation increasing. The influence ofwall slip with flow field and carrying capacity could be neglected.(3)Theoretical analysis on Reynolds formula of oil cavity with upper wallrotation and oil sealing pressure distribution were studied. The Reynolds formula of oil cavity with upper wall rotation is different to that of bearing one with another flowcharacteristic. Theoretical pressure of oil sealing calculated by Matlab reduces alongthe radius is same to that in numerical simulation.