Floating ring journal bearings of multilobe design in turbochargers

Abstract

The floating ring bearings system of turbocharger operates at high rotational speeds and high temperatures on the inlet of exhaust gases. Usually, such system applies the cylindrical profile of floating ring and stationary sleeve. The changes of the geometry of inner sliding surface of stationary sleeve as well as external or inner sliding surface of floating ring into multilobe surfaces allow for obtaining additional operation properties. It can be expected the changes in the static and dynamic characteristics of bearing what results in higher speeds of operation and better stability. The paper considers application of multilobe sliding surfaces in the design of turbocharger as well as the computation possibilities of such design bearings. Exemplary results of the computation of static and dynamic characteristics for the chosen types of multilobe bearings support their application in high speed rotating machinery including the floating ring bearings of turbochargers. Applied code and the results of this work allow calculating the stability of rotors operating in the bearings with the turbulent model of oil film and particularly the high speed floating ring bearings.