The smooth operation of the power transmission systems found in many
transport vehicles and energy production systems is often limited by the
reliability of the bearings which support their rotating shafts. Under
high shaft speeds and applied loads, hydrodynamic journal bearings may
constitute the only acceptable option for the designer.
When
predicting the performance of journal bearings submitted to severe
operating conditions it is crucial to account for the local variation of
the temperature and the viscosity field. Furthermore, the lubricant
supply conditions such as lubricant feeding pressure and temperature and
the actual groove geometry should be treated realistically in the
theoretical analysis.
The presentation will highlight the work
carried out during the speaker's recently finished PhD, a work that was
made within the Tribology team of the CT2M research group (Mechanical
Engineering Department, Minho University). It has been focused on the
theoretical and experimental study of the performance of twin groove
journal bearings operating under steady state. A particular emphasis was
put on the analysis of the influence of lubricant supply conditions.
The
work included the development of a Thermohydrodynamic (THD) model for
the analysis of the performance of twin groove journal bearings. The
model has been based on the simultaneous numerical solution of the
Generalized Reynolds and Energy equations within the lubricant film and
the heat transfer within the bush body. Special care was taken in the
treatment of the phenomena taking place in the vicinity of feeding
grooves and the modeling of the ruptured film region (solid+gaseous
phase).
The theoretical model was extensively validated and
refined with experimental results obtained at the Laboratory of
Tribology and Machine Elements of the University of Minho (LOMT), at the
Laboratory of Solid Mechanics of the University of Poitiers (LMS), and
with experimental results from the literature. |