An Experimental and Theoretical Examination of the Static Characteristics of Three-Lobe Bearings

Nine symmetric three-lobe bearings with preloads ranging from 0.00 to 0.88 and L/D ratios from 0.33 to 0.67 were tested with a rigid rotor. The load angle was also varied for each bearing. In this paper, the static operating characteristics are presented and compared to a theoretical solution. The experimental and theoretical relationships between the eccentricity ratio and Sommerfeld number were found to agree best for small values of bearing preload. The experimental and theoretical loci of operating points within the bearing clearance circle were found to agree best for large values of bearing preload. For positive values of preload, the operating position of the shaft in the bearing clearance circle was also found to approach the oil grooves for small values of Sommerfeld number. Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in San Francisco, California, August 18–21, 1980.