Theoretical Analysis of Externally Pressurized Porous Journal Gas Bearings : 1st Report

For externally pressurized porous journal gas bearings, an analytical solution has been obtained by introducing the concept of the so-called equivalent clearance, but it is not good enough because of the circumferential flow being neglected. In this paper, the authors have analyzed the gas flow of the bearing with added consideration of the circumferential flow in the bearing clearance and the porous bushing. The theoretical results are investigated experimentally, yielding a good conformity between them enough to certify the theory. Then, the optimum design conditions of the externally pressurized porous journal gas bearing are determined theoretically for the various factors which affect the bearing characteristics. Thus, it is made clear that the bearings with the porous bearing surface can have excellent static characteristics.