Thermal Expansion Simulation of Composite Hydrodynamic Thrust Bearings

Abstract

Fixed-geometry hydrodynamic thrust bearings rely on convergent geometry on the bearing face in the direction of relative motion to develop and maintain hydrodynamic pressure. Machining the convergent taper feature onto the bearing using traditional manufacturing processes can prove to be a difficult process due to the small magnitude of taper depth necessary for proper bearing performance. The work presented here investigates three different types of carbon fibers (AS-4/IM7/T-300) in an epoxy (3501-6) matrix for composite lamina formulation in taper-land composite thrust bearings as a means of controlling taper depth via thermal expansion so that favorable bearing functionality is maintained during load fluctuation without the need for traditional machining processes to create the taper. Thermal expansion of specific composite laminate formulation is analyzed using the ABAQUS/CAE composite module. The thermo-mechanical analysis shows that under realistic in-service temperature conditions resulting from bearing friction-torque, the thermal expansion of composite tapered-land thrust bearings expand to provide physical surface gradient magnitudes of 0.09504 mm, 0.08987 mm and 0.08829 mm that are capable of producing hydrodynamic pressure.