Aerodynamic Analysis of Spiral Grooved Gas Thrust Bearing

Abstract

Thrust bearings are designed to support the axial loads generated by the rotating component of turbomachinary like turbocharger and turboexpander. Aerodynamic gas thrust bearing like tilting pad, tapered pad, grooved has been successfully designed and developed. Previously it was difficult and costly to generate spiral grooves but now it easily be developed with laser machining process. Current research target to design and develop an alternative aerodynamic grooved thrust bearing with spiral pattern to find pressure profile, load carrying capacity and friction coefficient etc. In this analysis Reynolds Equation is solved by using the Finite Difference Method (FDM) to get the pressure distribution over the surface of the spiral grooved bearing. After the pressure distribution is known, load carrying capacity and friction coefficient is calculated and their variation with different parameters are presented. The suitability of designed bearing is checked for the designed turboexpander. Here the resultant axial thrust load is calculated for the designed micro turboexpander and this axial thrust load is compared with the load carrying capacity of the designed bearing. The author believe that the detail and procedural analysis will help the researchers to design and develop more alternative gas bearing for micromachinary like turbocharger and turboexpander etc.