Effect of rotational speed on transient thermoelastohydrodynamic tribo-dynamic characteristics of journal bearings

Abstract

In journal bearings operating under high-speed and heavy-load conditions, the loads borne by the bearings and the rotational speeds of the journals are the key parameters affecting their working characteristics. In this paper, taking journal bearings as the research object, the thermoelastic deformation of the bearing shell, the asperity contact between the journal and the bearing shell, the density-temperature-pressure and viscosity-temperature-pressure equations of lubricating oil, and the motion equation of the journal are comprehensively considered. Based on the generalized Reynolds equation of the average mass flow model, a transient thermoelastohydrodynamic (TTEHD) model of journal bearings coupled with dynamics and tribology is established. The established model is mainly aimed at the effect on the characteristics of bearings at different initial speeds and different lift speeds. The results show that: in the process of journal lift speeds, a larger lift speed will have a very obvious effect on the eccentricity and the maximum bearing temperature, and increase the possibility of journal vortexing; a larger initial speed will greatly reduce journal running stability; the increase of the load will to a certain extent strengthen journal stability.