Experimental Study on the Thrust-Radial Composite Porous Bearings with Hydrodynamic Shape Forming : Experimental Research of the Effects and Lubrication Characteristics of Radial or Thrust-Radial Composite Porous Bearings with Hydrodynamic Shape Forming on the Annular or on the End Surface

This study proposes the combination of some hydrodynamic pressure shapes formed on the end surface or on the annular surface of porous oil impregnated sintered bearing as a DC spindle motor's bearing system, and examines experimentally to optimize the hydrodynamic shape combination as thrust-radial composite bearing. Hydro Wave Bearing or Pump in as a thrust hydrodynamic shape, and Herringbone, Three lobed type or Sleeve (as a standard) as a radial hydrodynamic shape, were proposed, and the total of six kinds of combinations was produced as thrust-radial composite bearing. Floatation, temperature rise, friction torque and shaft whirling, such as the lubrication characteristics were examined experimentally. As experimental results, it was confirmed that low shaft whirling, energy-saving and life-longevity of bearing itself, were achieved by hydrodynamic pressure interaction of thrust-radial composite bearing.