Disclosed is a bearing sleeve for supporting a shaft of an air cycle machine. The bearing sleeve includes an outer diameter and an inner diameter. The outer diameter is within a range of 3.214 and 3.216 inches. Further included is a foil retaining cavity provided in the inner diameter of the sleeve. The foil retaining cavity includes a slot and first and second openings located at opposing axial ends of the slot. Each of the first and second openings include a small portion and a large portion having different axial lengths. A ratio of the combined axial lengths of the large portions to an axial length of the foil retaining cavity is within a range of 0.19:1 and 0.22:1.