Rotating anode X-ray tube with improved thermal capacity
AssigneeGeneral Electric Company
InventorsRobert E. Hueschen, Richard A. Jens
Life of this patent
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Abstract
A low thermally conductive columbium metal stem has a heavy refractory metal x-ray target disk fastened to one end. A high thermal conductivity rotor hub comprising a cup-shaped element is fastened to the other end of the stem and the rotor hub is fastened to the end of an induction motor cylinder or liner which is coated to enhance heat emission and is induced to rotate by being coupled to a rotating magnetic field. A low thermally conductive bearing hub is fastened to the inside of the rotor hub and to a shaft which is journaled for rotation in bearings. The bearing hub enhances thermal isolation of the bearings from the hot rotor hub and hot target.
Claims7
In a rotating anode x-ray tube comprising an envelope, a shaft journaled in bearings for rotation within said envelope, a rotatable x-ray target disk and a coaxial stem on which said disk is mounted, an elongated cylindrical element in said envelope surrounding said shaft concentrically and subject to be rotated under the influence of a magnetic field and treated on its surface for enhancing thermal emission, a rotor hub for coupling said stem to said cylindrical element and a bearing hub for coupling said rotor hub to said shaft, the improvement for increasing the thermal capacity of said tube by restricting the flow of heat flowing from said target disk to said bearings and by increasing the flow of heat flowing to said cylindrical element wherein:
- said rotor hub is made of high thermally conductive molybdenum-based alloy having a conductivity at 500.degree. C. of at least 0.29 cal/cm.sup.2 /cm/sec/.degree.C. and is comprised of no less than 99.25% of molybdenum,
- said bearing hub is made of low thermally conductive nickel-based alloy having a conductivity at 500.degree. C. of one-seventh or less than one-seventh of the conductivity of said molybdenum-based alloy and is comprised of no less than about 45% and no more than about 67% of nickel, and
- said stem is composed substantially of columbium and is non-tubular.
Dependencies are inferred from the claim text.