Hybrid air foil bearing and method of manufacture

A method of manufacturing an air foil bearing comprising the steps of:

• providing one or more the orifice tubes wherein each orifice tube has a flat side, a closed end, an open end, and a bend proximate to the open end;
• providing a top foil;
• providing a housing having an opening extending through the housing to receive the open end of each orifice tube;
• creating a foil-tube assembly by attaching the flat side of the orifice tube(s) to an outer surface of the top foil, creating a set of holes through the inner surface of the top foil and the flat side of the orifice tube to form a set of top foil orifice holes and corresponding orifice tube holes, and attaching a bump foil strip to the outer surface of the top foil adjacent to each side of each orifice tube;
• forming the foil-tube assembly into a substantially circular shape;
• and
• inserting the foil-tube assembly into the housing such the open end of the orifice tubes extends through the housing openings.

An air foil bearing for supporting a shaft by an air layer formed between a substantially circular inner surface of a housing and the shaft, the air foil bearing comprising:

• a top foil comprising three or more top foil sections formed into a substantially circular shape having one or more sets of top foil orifice holes, wherein each set of top foil orifice holes comprise at least three top foil orifice holes along a circumference of the circular-shaped top foil;
• an orifice tube for each set of top foil orifice holes, wherein the orifice tube comprises (a) a flat side having a set of tube orifice holes such that each tube orifice hole is substantially aligned with one of the top foil orifice holes when the flat side of the orifice tube is connected to an outer surface of the top foil sections, (b) a closed end, (c) an open end, and (d) a bend proximate to the open end;
• a bump foil strip attached to the outer surface of the top foil sections adjacent to each side of each orifice tube;
• and
• wherein the housing further comprises a circumferential groove formed on the inner surface to receive each orifice tube and an opening extending through the housing into the circumferential groove to receive the open end of each orifice tube.