A transient and time lag deformation alternating-coupling micro elastohydrodynamic lubrication model

Abstract

As transient and time lag deformations occur alternately and influence each other for viscoelastic materials of dynamically loaded journal bearings, the time lag deformation per unit time is defined based on the finite element stiffness equation and the standard linear solid model, accumulating it by loop and superposing transient deformation to obtain actual deformation at every moment. Thereby, a novel temporal association deformation equation of bearing is constructed. It is used to improve the film thickness calculation method of the traditional micro elastohydrodynamic lubrication (MEHD) model. Finally, a novel transient and time lag deformation alternating-coupling micro elastohydrodynamic lubrication (TTL-MEHD) model is established. The comparison between lubrication performance parameters calculated by the new model and the MEHD model under the eccentric motion of the journal proves the new model is correct, and can effectively analyze the knocking and rough rubbing characteristics at the early stage of bearing instability. The new model is implemented to explore the effect of the time lag degree of material deformation on mixed lubrication performance. The application of the new model in connecting rod bearing of internal-combustion engine proves that it can effectively compensate for the impact lag deviation caused by the complete elasticity assumption.