Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Rotor Vibration Control Using Hydrodynamic Bearing With Active Pads
Submission Author:
Rodrigo Nicoletti , SP , Brazil
Co-Authors:
Heitor Antônio Pereira da Silva, Rodrigo Nicoletti
Presenter: Heitor Antônio Pereira da Silva
doi://10.26678/ABCM.COBEM2021.COB2021-0067
Abstract
Large rotating machines are elements of great importance to the production chain and they can eventually operate under unpredicted or off-the-norm conditions, thus resulting to failure and significant economic losses. One way of reducing the consequences of such off-the-norm operation of these machines is the modification of the characteristics of the bearings that support the rotor. However, with conventional bearings, this is only possible through complete stops of the machine, which also result to economic losses. The solution to this problem comes from the development of active bearings that can change the dynamic characteristics of the machine during operation without needing machine stops. In this sense, the present work presents a tilting-pad journal bearing whose pads are controlled by electromagnetic actuators (an innovative design solution). By mounting the electromagnetic actuators in the bearing casing, behind the pads, one can exert electromagnetic forces on the pads and make them change their angular position in relation to the bearing. Hence, one can modify the dynamic characteristics of the rotor-bearing system for desired and more appropriated values for a given operational condition, thus reducing the need of machine stops and the consequent economic losses. In this work, we present the mathematical model of such system and numerical simulations of the system in open- and closed-loop conditions. The bearing and the rotor are modeled by rigid-body dynamics, and the lubricant interface is modeled by the Reynolds equation. The dynamics of the electromagnetic actuators are identified experimentally and used in the model as a transfer function representation. A proportional-derivative controller is adopted in the closed-loop simulations.
Keywords
Active Vibration Control, active bearing, tilting-pad bearing, electromagnetic actuator, Rotordynamics
