Performance and Durability of High Temperature Foil Air Bearings for Oil-Free Turbomachinery

Stiffness and Damping Coefficient Estimation of Compliant Surface Gas Bearings for Oil-Free Turbomachinery

“…In the case of the Oil-Free turbocharger demonstration, increased spring preload while avoiding bearing overload was possible because the excellent load capacity coefficient (D~1.0) provided satisfactory margins on load capacity (Ref. 34). Several commercial manufacturers are now coming to market with similar machines (Refs.…”

Design, Fabrication, and Performance of Open Source Generation I and II Compliant Hydrodynamic Gas Foil Bearings

“…The bearing is placed on the shaft and the shaft diameter is sized to provide a low spring preload (interference fit) of around 3.4 kPa (0.5 psi)) with the bearing. The preload level is determined by conducting breakaway torque measurements at varying deadweight loads using the method described in the literature [15]. Reference 27 describes in more detail the effect preload level, influenced by shaft diameter, has on bearing performance.…”

“…For low temperature bearing applications, polymer based films such as PTFE (polytetrafluoroethylene) are effective at reducing friction and wear [14]. For high temperature applications, metal-ceramic coatings have proven successful [15].…”

Rotordynamic Performance Measurements of An Oil-Free Turbocharger Supported on Gas Foil Bearings and Their Comparisons to Floating Ring Bearings

“…For rotor parts, the turbine wheels and compressor wheels are located on both ends, and the shaft is supported by a pair of journal GFBs and a pair of thrust GFBs. GFBs absorb the thermal expansion of the shaft at high temperatures due to the deformation of the foil structure, and improves the damping characteristics by means of the dry friction between the foil and housing [2][3][4].…”