On the non-linear behaviour and orbit patterns of rotor/stator contact with a non-conventional containment bearing

• Non-linear patterns of a rotor with a non-conventional bearing.
• Impacts between rotor and retainer bearings׳ pins.
• Impact force bifurcation diagram.
• Experimental validation of the dynamic behaviour.
• Crossing critical speed with the aid of pins.

The present work is a numerical study with experimental validation of the non-linear behaviour of a rotor interacting with a non-conventional back-up bearing. When the rotor׳s movement in the (x,y) plane reaches an undesirable amplitude, such movement is restrained by the new bearing, composed by pins. These pins receive all the impacts, working as a containment bearing. This work presents a numerical study of the rotor impacting on the pins and later compares it with experimental data extracted from a vertical rotor test rig. While conducting numerical simulations, the results show the different characteristics of the rotor orbit, depending on the applied torque. The steady state trajectories formed singular geometries, different from each other. A set of data was collected, showing this interesting rotor/stator interaction due to impacts with the pins. The results include various non-linear features, such as bifurcations and chaos. Furthermore an experimental test rig is mounted and the position of the rotor inside the modified safety bearing is measured and the result is compared to the simulation presented.