Experimental study on the lubrication characteristics of porous journal bearings with hydrodynamic shape forming at annular surface under sine-wave vibrated conditions (Examination into the shaft rotating behavior at the starting state by identifying the rotational modes with Frequency Spectrum Analysis of the time history waveform on shaft)

Abstract

This report describes the study on the lubrication characteristics of porous journal bearings, which were made with oil impregnated sintered materials having some hydrodynamic shapes, to apply them for a DC Spindle Motor’s bearing system. Herring Bone (I & II), Three Lobed Type or Sleeve as radial hydrodynamic shapes were proposed, and four kinds of specimens were produced for porous journal bearings with pivot supported shaft conditions. They were examined experimentally to optimize the hydrodynamic shape of porous journal bearings by measuring the lubrication characteristics at the shaft starting state under sine-wave vibrated conditions. This report particularly refers to the experimental examination into the shaft rotating behaviors, which were identified the rotational modes with Frequency Spectrum Analysis of Time History Waveform (T.H.W.) of the shaft such as the above-mentioned lubrication characteristics under the same conditions. Furthermore, it was investigated to discuss the influences of vibrated frequency changes to the lubrication characteristics by measuring the T.H.W. of the shaft under the above conditions.

Keywords

• porous journal bearing
• hydrodynamic shape forming
• time history waveform
• shaft rotating behavior
• sine-wave vibrated condition
• vibrated frequency change
• frequency spectrum analysis