Haruo Mori

Theoretical Study of Externally Pressurized Gas-Bearing

Analytical solutions of the pressure distribution of externally pressurized concentric journal or parallel surface thust bearings are obtained for compressible and incompressible fluids, for several bearing configurations, by means of complex potential functions. Flow rates, and approximate evaluations of the effects of eccentricity and sliding speed, are also obtained. A bearing design factor for restrictor compensated bearings is presented, and optimum values for maximum bearing stiffness are determined. Comparisons are made between theoretical calculations and available experimental data.

On the Graphite-Air Mist Lubrication of the Ball Bearing at High Temperature

The need is becoming more and more urgent for bearings operating at very high temperatures. But present-day liquid lubricants are temperature-limited owing to their characteristics, but graphite is chemically more stable and capable of being used as a lubricant. So in pursuit of information concerning the performances of the angular contact type ball bearing operating in an electric furnace under the graphite-air mist lubrication at high temperature, the frictional moment and temperature of bearing have been measured. The conclusion reached on the experimental results is as follows. The bearing can be run at surrounding temperatures up to 800°C without appreciable damage. The smaller the particles of graphite, the less frictional moments are obtained, but at very high temperatures the grading and consumption of graphite have little influence on the frictional moment. Small change in frictional moment occurs in accordance with variation of surrounding temperature. The moisture content of graphite has little influence on the frictional moment. The cooling effect of air is somewhat remarkable.

The Hydrodynamical Theory of Multiple-Film Journal Bearings

Several kinds of journal bearings, which are designed to have a multiplicity of convergent oil films in the bearing instead of the conventional journal bearings whch have single oil film in the bearing, are used as precision high speed bearings with very little clearance. Now, the multiple-film journal bearings having some fixed bearing surfaces of eccentric circular arcs are investigated theoretically to find the pressure distribution, the load capacity, the locus of center of shaft and the frictional resistance, because few theoretical investigations for the multiple-film bearings have been reported. So the designing factors to be determined in accordance with the particularity of the multiple-film journal bearings are described in this paper.