Experimental investigation of ceramic ball bearings for microturbines
More details
Hide details
Instytut Maszyn Przepływowych PAN
Artur Andrearczyk   

Instytut Maszyn Przepływowych PAN, Fiszera 14, 80-231 Gdańsk, Polska
Submission date: 2017-01-30
Acceptance date: 2017-02-20
Publication date: 2017-03-23
Diagnostyka 2017;18(1):51–58
This article presents the experimental research on ball bearings, which could be applied in vapour microturbines operating in CHP systems. The bearings are of three kinds, according to their constructional solution: 1. all-steel (all components are made of steel); 2. ceramic-steel-hybrid (ceramic balls, steel cage and races); 3. all-ceramic (the balls, as well as external and internal races, are made from ceramic silicon nitride – Si3N4, while the cage is made of PTFE). The test rig and the research method were discussed. In order to have a better picture of vibrations of the rotor-bearing system, we applied the bearing system with a flexible rotor. That option entailed some difficulties, however. In each case, both the analysis of the ball bearings' properties and of the impact of ceramic components on the dynamic performance of the rotor was carried out. The results of these analyses are presented in the following forms: displacement amplitudes of the rotor, colormap graphs of the type Order Analysis Order Spectrum and three-dimensional vibration trajectories. The bearings were analysed on the basis of colormap graphs, while the analysis of the rotating rotor was conducted using graphs depicting 3D vibration trajectories and displacement amplitudes at the disk location. As a result of all this work that we have mentioned, useful information on the possible application of tested bearings for vapour microturbines has been gained.