Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Hydrodynamic cylindrical journal bearing for experimental validation of numerical models
Submission Author:
Ely Queiroz Gomes , MG , Brazil
Co-Authors:
Ely Queiroz Gomes, Leonardo Sicchieri, Aldemir Ap Cavalini Jr, Valder Steffen Jr
Presenter: Ely Queiroz Gomes
doi://10.26678/ABCM.COBEM2023.COB2023-1190
Abstract
Cylindrical hydrodynamic journal bearings are elements of rotating machines with a wide range of applications, from small engines to large turbo generators. Its operation is based on the principle of a thin film of oil that promotes the separation between a rotating shaft and the bearing, preventing contact between the surfaces. This thin separation film is the result of oil pumping that occurs due to its contact with the rotating shaft. Pumping generates a pressure field acting on the surface area of the shaft, promoting a force that sustains the applied load. There are several lubrication numerical models developed to represent the behavior of hydrodynamic bearings. These models are classified according to the lubrication condition, which can be hydrodynamic, thermohydrodynamic, elastohydrodynamic, and thermoelastohydrodynamic. However, regardless of the model, the determination of the lift pressure is generally obtained through the solution of the Reynolds Equation. Aiming at the experimental validation of these numerical models, it is necessary to design and manufacture a bearing capable of being instrumented to monitor variables that will be confronted with the simulation. This work aims to present the design and tests of a radial cylindrical bearing used in the experimental validation of a numerical model. This model is capable to estimate the pressure field and temperature field of the oil film subjected to different operating conditions and different lubrication regimes. So, to monitor the oil film temperature along the bearing surface 16 thermocouple sensors distributed equally spaced along its circumferential length were used. This same scheme was also adopted for the acquisition of pressure data, with 16 pressure transducers distributed similarly to the scheme for temperature measurement. Communication between the sensors and the fluid takes place through a small hole in the bearing surface. To impose different lubrication conditions, a hydraulic unit with proper instrumentation and volumetric capacity was used to supply oil to the bearing. According to the tests already carried out, it was possible to verify the correct functioning of the bearing and its ability to provide accurate data on the monitored variables.
Keywords
hydrodynamic journal bearing, test rig, Data aquisition
