INTERNAL BEARING COOLING USING FORCED AIR

摘要

A high energy x-ray tube includes an evacuated chamber (12) containing a rotor (34) which rotates an anode (10) through a stream of electrons (A) in order to generate an x-ray beam (B). The rotor includes a bearing assembly (C) having a hollow bearing shaft (52) centrally aligned with a longitudinal axis (z) of the rotor. The bearing shaft includes an interior annular wall (54) having an inner surface which defines a central bore (58). The bearing shaft has an outer surface (60) which, with an inner surface of the bearing shaft, defines an annular chamber (62). An opening (64) is provided at the forward end of the annular wall to provide access from the central bore to the annular chamber. During exhaust processing, baking cycles, and normal operation of the x-ray tube, a pump (104) forces a cooling medium through the central bore, through the opening of the annular wall, and into the annular chamber. The cooling medium exits through channels (66). While in the annular chamber, the cooling medium cools a plurality of forward and rearward lubricated bearings (48F, 48R) located adjacent an outer surface of the hollow shaft.