Application of the Controllable Magnetorheological Squeeze Film Dampers for Minimizing Energy Losses and Driving Moment of Rotating Machines

The energy losses generated in rolling element bearings rise with increasing magnitude of the force transmitted between the rotor and the stationary part. A frequently used technological solution, which makes it possible to minimize the transmitted force, consists in adding damping devices to the rotor supports. To achieve their optimum performance in a wide range of operating speeds, their damping effect must be adaptable to the current angular velocity. This is offered by magnetorheological squeeze film dampers. Their main parts are two concentric rings separated by a layer of magnetorheological oil. Its squeezing produces the damping force. As magnetorheological fluids are sensitive to magnetic induction, the change of magnetic flux passing through the lubricating film changes the damping force. The goal of the carried out investigations was to study the influence of controllable damping in rotor supports on energy losses and driving moment of the motor in different velocity ranges. The investigations were performed by computational simulations. The rotor was rigid, supported by magnetorheological squeeze film dampers, and excited by its unbalance. The results show that appropriate adaptation of the magnitude of the damping force to the current operating speed arrives at minimizing the energy losses generated in the rotor supports. The performed analysis shows a new possibility of magnetorheological squeeze film dampers, which leads to improvement of performance of rotating machines and points out at a new field of their prospective application.