Session: 03-28-01: Joint Session on Recent Advances in Advanced Materials Processing and Tribology

Paper Number: 94853

94853 - Thermo-Mechanical Analysis of a Composite Tapered-Land Hydrodynamic Thrust Bearing Sector Manufactured Using Fused Filament Fabrication 

Tapered-land hydrodynamic bearings are a type of fixed geometry or fixed pad hydrodynamic bearing. During hydrodynamic operation, a pressurized lubricant film is formed so that the rotating and axially loaded surfaces can be separated and operate with low friction coefficients. Required taper depths are predetermined and machined on the bearings during manufacturing. The taper depth machined on the bearings is selected based off of expected applied axial loads and rotational speeds that the bearing will operate under; efficiency is negatively impacted if the bearing were to operate outside of these conditions. Heat formation that occurs during hydrodynamic bearing operation is due to frictional forces encountered from shearing of the lubricant and is dependent on lubricant viscosity, applied axial load, and rotational speed. Consequently, the bearing sectors or pads on the bearing are also subjected to heating due to the temperature rise of the lubricant. Previous research has investigated the use of composite laminates to mitigate machining in tapered-land hydrodynamic bearings. Recent thermo-mechanical analysis indicated that composite laminates may be a viable alternative to the traditionally machined metallic tapered-lands on hydrodynamic bearings. A previous study on this topic concluded that the lamina directions of a composite laminate can be selected to exploit both the thermal expansion and heat produced during operation so that a self-forming hydrodynamic pressure producing taper curvature is created during bearing operation. This critical result shows the potential of eliminating the need to machine the tapered section on the bearings and thus reduce manufacturing time, labor, and other associated machining costs. The work presented here aims to expand the research on replacing traditional metallic based tapered-land hydrodynamic thrust bearings with composite materials. The use of fused filament fabricated carbon fiber filled polyamide (PA) as a base material for hydrodynamic tapered-land thrust bearings is explored. Experimental analysis was conducted on fused filament fabricated carbon fiber filled PA samples to obtain thermal expansion coefficients along the longitudinal and transverse directions with respect to the 3D print orientation. Thermo-mechanical analysis was then conducted in ABAQUS/CAE to show that taper formation occurs as bearing pads undergo thermal gradient and expansion during hydrodynamic bearing operation. The data obtained in this analysis provides evidence that fused filament fabrication of composite materials can be used to reduce manufacturing cost of traditional metallic hydrodynamic bearings; these methods can also be utilized to tailor the bearings to operate within a larger range of rotational speeds and applied axial loads.      

Presenting Author: Collier Fais Ohio University

Presenting Author Biography: Collier Fais is a Ph.D. candidate in Mechanical Engineering Dept. at Ohio University.

Authors:

Isaiah Yasko Ohio University
Lloyd Furuta Ohio University
Collier Fais Ohio University
Muhammad Ali Ohio University
Brian Wisner Ohio University