NOVELTY - The air bearing assembly (200) has bearing sleeve (210) whose inner surface defines a first retention slot (250) configured to engage a first end of a first bearing foil (230) and a first end of a second bearing foil (240). The inner surface of the bearing sleeve defines a second retention slot (260) spaced from the first retention slot and configured to engage a second end of the second bearing foil, such that the first and second bearing foils are maintained in engagement with the bearing sleeve through an engagement of the respective ends with a corresponding one of the slots.    USE - Air bearing assembly for turbomachinery shaft such as for use with turbochargers or fuel cell turbocompressors for fuel cell.    ADVANTAGE - The dual-slot design replaces the complex L shaped single slot design of conventional bearing sleeves, allowing for high-volume and low-cost manufacturing of the bearing sleeves. The dual-slot design also provides for robust engagement of the bearing foils with the bearing sleeves, while allowing easy assembly and installation of the air bearing assemblies. The bearing sleeves are simpler and more cost effective to produce and provide a design that is more easily manufactured for different sizes and configurations of dual-stage compressors. The second retention slot can be angularly positioned within the bearing sleeve to accommodate or facilitate ease of assembly of the bearing foils to optimize the bearing load when the compressor is operating, and/or to meter or bypass cooling air flow in conjunction with the end ring retainer groove configuration through the bearing assembly into the rotor cavity. The high volume of bearing sleeves can be produced accurately and efficiently at a relatively low cost, especially as compared to conventional bearing sleeves with more complex cross-sections requiring processes.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a bearing sleeve for an air bearing assembly configured to support a turbomachinery shaft; and    (2) a method of manufacturing a bearing sleeve for an air bearing assembly.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of an air bearing assembly.    Air bearing assembly (200)    Bearing sleeve (210)    First bearing foil (230)    Second bearing foil (240)    First retention slot (250)    Second retention slot (260)