Mathematical model of a radial sliding bearing with a porous layer on its operating surface with a low-melting metal coating on shaft surface

Abstract

The paper considers the steady flow of a liquid lubricant and a melt of a low-melting metal coating of the shaft surface, which have viscous rheological properties in the operating clearance of an endless radial sliding bearing, as well as in the body of the porous coating of the surface of bearing bush. In order to solve this problem, the authors used the equation of the movement of viscous lubricant for a thin layer, the equation of continuity and also the equation describing the radius of the molten contour of the fusible coating of the shaft surface, taking into account the rate of dissipation of mechanical energy. Having averaged the acceleration of the movement of the liquid lubricant in the operating clearance, the authors obtained the dependence for the contour of the molten coating of the shaft surface. As a result of the integration of the obtained dependence, the expression was found that allowed solving the function characterizing the contour of the molten surface of the coating by the method of successive approximations. Using the well-known method of finding an exact self-modal solution, the velocity field and pressure in the lubricating and porous layer, as well as the load capacity and friction force, were found. On the basis of the performed theoretical studies, the experimental study was carried out taking into account the parameters characterizing the melt of a low-melting metal coating, as well as a porous coating on the surface of the bearing bush and the rheological properties of a viscous lubricant. As a result, the original expression was obtained for the calculation of the load capacity of a radial bearing and the magnitude of the friction force in the range under the following loading conditions v=0.5÷3 m/s, σ=2÷7 MPa. The research results can be used in mechanical engineering, aircraft construction, instrument engineering, where the supply of lubricant is associated with great difficulties.