Mechanical Systems and Signal Processing

• Different types of controllable journal bearings are listed and described. • Various applications of controllable bearings are mentioned. • A comparison between passive and controllable bearings was made. • Advantages and disadvantages of controllable bearings are presented. • Possible directions of the future development of controllable bearings are indicated. Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).

Research and applications of active bearings: A state-of-the-art review