Experimental Assessment of a 3D-Printed Stainless Steel Gas Foil Bearing

Abstract

Gas foil bearings (GFBs) are a key enabling technology for high-speed turbomachinery. The manufacturing of GFBs relies mainly on sheet metal forming techniques in order to conceive the compliant structure (e.g., bump foil) and the top foil. Such techniques require the development of a special know-how and most importantly, limit the design creativity to what is manufacturable using sheet metal forming. Additive manufacturing (AM) is a disruptive technology in prototyping and fabrication. This paper accesses the feasibility of AM in the fabrication of GFBs using selective laser melting (SLM) technology. A stainless steel GFB is 3D-printed in one piece, including the sleeve, the bump, and top foils. The bearing is assessed geometrically and statically before being tested on a gas bearing test rig, where it supported a ø40 mm rotor (m = 2 kg). The bearing performed similar to a conventional GFB, showing rotordynamically stable and repeatable operation up to 37.5 krpm. Such result highlights the potentials of AM as a viable alternative for foil bearing manufacturing.