High-Speed Hermetic Turbogenerator with a Hybrid Bearing System

Abstract

In the power industry, the most commonly used hydrostatic bearings are usually oil lubricated. On the contrary, for a distributed combined heat and power production, in the working machine—a hermetic high-speed turbogenerator—an oil-free bearing system is required. For this purpose, hydrostatic bearings lubricated with an organic, oil-free working fluid have been designed. Characterized by its limited lift force, hydrostatic bearing system can be used in small-power turbomachinery. To expand the functionality of the application, a new type of bearing—a hybrid bearing—was designed, built, and tested. In this new bearing, both hydrostatic and hydrodynamic effects are combined. In addition, a magnetic thrust bearing has been designed, so that the whole hybrid bearing system is characterized by hydrostatic, hydrodynamic, and magnetic effects. To confirm the good stability of rotor dynamics, numerical calculations and experimental tests have been conducted. The presented design resulted in good bearing lift and reliability of the bearing system.