ACTIVERING
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Project implemented under the LIDER IX Programme of the National Centre for Research and Development
Agreement No LIDER/51/0200/L9/17/NCBR/2018
Project title: Active foil bearings with variable dynamic properties
Project acronym: ACTIVERING
Project Manager: Dr. Łukasz Breńkacz
Period of implementation: 1 January 2019 – 30 June 2022
Project summary:
As part of the project, a new type of bearing was developed – an active foil bearing. The whole design process was carried out from concept analysis to numerical analysis to experimental research. As a result of the work, unique structures such as the first 3D printed bearings were created, whose changes in geometry were due to the use of flexible plastic properties. Another test design was to assume pans of foil bearing divided into segments, this solution was also made and tested for the first time in the world. The concepts analysed are contained in two patent applications.
At the beginning of the work, precise numerical analyses were performed. Both the dynamic properties of the rotor supported on active foil bearings and a number of operating parameters of the future bearing were tested. Characteristics have been made, e.g. from which speeds a lubricant film will be produced, and the interaction between fluid and structure has been analysed. It was analysed how the rotor dynamics changes during the circular-cylinder change in the diameter of the bearing and during the elliptical changes. Separate bearing models were created, which were used to analyze the control of the PID-based bearing. Since the bearing model was fully defined, it was possible to optimize the settings of the PID regulator even before performing experimental studies.
Bearing design began with the choice of actuators – elements to change the geometry of active foil bearing. Various possible solutions were analysed, and then several most promising ones were examined in the laboratory (e.g. materials with shape memory, step motors, piezoelectric stacks, stepper motors and servomechanisms). They have been tested in a laboratory in conditions similar to those of an active foil bearing. The best actuators were used during the construction of the active foil bearing.
Two prototypes of active foil bearing and several modifications were built. There was also a research infrastructure with two laboratory sites. The first laboratory station was made up of electro-spindle drive. Active foil bearings were ‘suspended’ at this position and it was possible to change their operating parameters and analyze the point of friction, amplitude of vibrations, temperature and other operating parameters. At the second turbine-powered test bench, two active foil bearings were fitted and tested in similar conditions to that of actual ones.
Based on the work done, two prototype bearings with unique properties were created. These properties can make the active foil bearing able to be used in devices in which classic foil bearings could not be used, e.g. due to too much starting torque. During the tests it was revealed that the starting moment could be reduced more than twice.
Project amount: PLN 1 200 000,00
Grant amount of NCBR: PLN 1 200 000,00
Project page: https://activebearing.com