Search

In this paper, an elastic sphere approaching a lubricated elastic coating surface with couple stress lubricant is explored under constant load condition. The finite difference method (FDM), Gaussian elimination, and Gauss-Seidel iteration method are used to solve the transient modified Reynolds equation with its boundary condition, the elasticity deformation equations of ball and coating layer, load balance equation, and lubricant rheology equations simultaneously. The transient pressure profiles, film shapes, and elastic deformation during the pure squeeze process under various operating conditions in the elastohydrodynamic lubrication (EHL) regime are discussed.

The pure squeeze magneto-elastohydrodynamic lubrication (MEHL) motion of circular contacts with an electrically conducting fluid in the presence of a transverse magnetic field is explored under constant load condition. The differences between classical elastohydrodynamic lubrication and MEHL are discussed. The results reveal that the effect of an externally applied magnetic field is equivalent to enhancing effective lubricant viscosity. Therefore, as the Hartmann number increases, the enhancing effect becomes more obvious. Furthermore, the transient pressure profiles, film shapes, normal squeeze velocities, and effective viscosity during the pure squeeze process under various operating conditions are discussed. [DOI: 10.1115/1.4002182] Keywords: magneto-elastohydrodynamic lubrication, squeeze-film, constant load

In this study, the nonlinear dynamic analysis of the hybrid squeeze film damper mounted on a gear-rotor-bearing system is presented. The strong nonlinear oil film force, nonlinear rub-impact force between the rotor and stator, and the gear meshing force are considered in this study. The bifurcation diagrams are plotted using a dimensionless imbalance factor, damping coefficient, and speed ratio as control parameters in this study. The beginning of chaotic motion is identified by phase diagrams, power spectrum, Poincaré maps, bifurcation diagrams, maximum Lyapunov exponent, and the fractal dimension of the system. The numerical results provide useful insights into the design and development of a gear-rotor-bearing system for rotating machinery that operates at high speeds and highly nonlinear conditions. Hybrid squeeze film damper is used to suppress irregular dynamic behaviors and reduce greater amplitude, even if the rotational speed of the rotating machine is higher, which is also confirmed in this study. [ABSTRACT FROM AUTHOR]