Patent ID: 6385293
Filing Date: 2002-05-07
Classification: F16C,H01J

Abstract:
An x-ray tube for providing a beam of x-rays, the tube comprising:an envelope which defines an evacuated chamber; a cathode disposed within the chamber for providing a source of electrons; an anode disposed within the chamber which is struck by the electrons and generates x-rays; a rotor for rotating the anode relative to the cathode, the rotor including: a shaft which defines an interior cavity; a forward bearing race and a rear bearing race on the shaft, the forward bearing race being closer to the anode than the rear bearing race; a rotor core disposed within the cavity and having a high thermal conductivity such that heat is conducted by the core in a direction away from the anode, a first region of contact being formed between the shaft and the rotor core forward of the forward bearing race and a second region of contact being formed between the shaft and the rotor core intermediate the forward and rear bearing races, the first and second regions being spaced by an insulating region, the first and second contact regions being sized to balance temperatures of the forward and rear bearing races; the forward bearing race being of a lower conductivity than the core, such that the core conducts heat past the forward bearing race; and lubricated bearings received in the forward and rear bearing races.