The increase in the power and efficiency of the newly developed rotating mechanisms is inextricably linked with the growth of their rotation speeds and the overall level of vibration. Gas-dynamic foil bearings have a higher priority for use in high-speed mechanisms due to their practically unlimited maximum speed, the absence of an additional lubrication system, low friction power losses, etc. However, increased friction and low load-carrying capacity during the start-stop period is a problem for the further application of gas-dynamic foil bearings. The hybrid bearing studied in this work includes a rolling-element bearing, a gas-dynamic foil bearing and actuators. The hybrid bearing studied in this work includes a rolling-element bearing, a gas-dynamic foil bearing and actuators. Actuators allow during operation to switch from one type of bearing to another, as well as to control the radial gap of the gas-dynamic foil bearing, changing the dynamic characteristics of the hybrid bearing. The new designed hybrid bearing was manufactured and tested on a rotordynamic test rig in this study. A theoretical model of the hybrid bearing rotor system was built and demonstrated by the experiment results.

Abstract. The design and the modal analysis of a small turbocharger rotor system are carried out in this paper. The design process and method of rotor system are summarized. Some useful conclusions are obtained in the modal analysis. These results will provide engineers with valuable information about the vibration characteristics of the turbine rotor system and the design of the rotor system.