Siemens Aktiengesellschaft

Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Ernst Geldner

Rudolf Friedel

Horst Schreiner

Johan K Fremerey

Karl Boden

Klaus Haberrecker

Friedrich Gudden

George Comsa

Gunther Appelt

A rotary anode X-ray tube has an anode connected at one end of a shaft which is magnetically mounted within the X-ray tube at its opposite end, the shaft simultaneously forming a rotor connected to a drive system for rotating the anode. The X-ray tube housing is formed by a number of connected components, two such components being spaced at opposite ends of the rotor, with the rotor extending therethrough, and each having stop bearings which are normally not in contact with the rotor, but which serve to limit movement of the rotor and the anode connected thereto, in the event of a malfunction in the magnetic mounting. Integration of the anode shaft and the drive rotor enable placement of the stop bearings at locations which minimize the lever action of the rotor-shaft-anode combination thereby significantly improving stability of the total assembly.

Rotary anode X-ray tube

In exemplary embodiments, the anode is driven by an induction motor, between the stator and rotor of which the wall of the vacuum envelope of the tube is disposed. To reduce the overall length and the lever actions of the weight of the anode which act on the bearing which are disadvantageous in this construction, the disclosure provides an annular anode which is disposed in the same plane with the drive rotor. The rotor and stator can here be surrounded by the ring of the anode or they can be secured externally about the latter. X-ray tubes in accordance with the disclosure are particularly suited for use for the purpose of medical x-ray examination.

A rotatable anode for an X-ray tube comprising a body composed of a porous, difficult to melt material enclosed in a sealed fashion within an enveloping layer of a difficult to melt material, characterized by the porous body being of a material having a good thermal conductivity and a good thermal capacity and said porous body having its pores filled with a material having a good thermal conductance and being a good conductor of heat. The porous body is preferably a sintered porous body. The material of the porous body as well as the material of the enclosing layer are selected from a group consisting of tungsten, molybdenum, niobium, chromium, vanadium, titanium, carbon, alloys of these materials, and compounds of these materials. The filler material is preferably a metal selected from a group consisting of silver, gold, copper, aluminum, and alloys of these elements containing not less than a predominant proportion of at least one of these metals. The enveloping layer may be in the form of a sheet material container and lid which are tightly sealed together such as by welding or may be formed of a layer or coating of a portion of the porous body which layer or coating is tightly sealed to a sheet metal portion such as a lid.

Rotatable anode for an X-ray tube composed of a coated, porous body

Tubular electromagnetic components are mounted on the drive shaft of the ary anode of an X-ray tube and external magnet windings are provided both for maintaining the drive shaft in an axial position corresponding to a working position of the anode and for shifting the drive shaft to open a slip contact at one end thereof, thus providing a magnetic switch for the anode supply voltage. In addition, windings are provided through which a controlled current flows to provide a radially stabilized position for the shaft and thus constitute magnetic bearings that are free of friction. When one of the contacts of the magnetic switch is spring-mounted, the coil that does the switching can also be used to adjust the axial position of the anode so as to work with a different cathode.

A layered pressed and sintered anode body consisting of a support body of a tungsten-molybdenum alloy having a first layer of tungsten or tungsten alloy on the surface which is impinged by electrons and having a second layer of a higher melting point material on the other side whose tensile strength at the elastic limit is greater, at temperatures of 1400.degree. to 1600.degree. C, than the tensile stresses occurring at these temperatures to avoid warping of the anode.

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Rosstal, Germany

Ernst Geldner