Abstract: A rotary anode type X-ray tube has an enclosure, a target rotatably supported within the enclosure and serving as a source of X-ray generation, a cylindrical rotor connected to the target, for rotating the target by the action of rotating magnetic field produced by a winding provided around the enclosure, a rotary shaft on the central axis of the rotor for rotation of the target, and a stationary cylindrical housing concentric with the rotor interposed between the rotor and the rotary shaft, for supporting the rotary shaft through rolling bearings. In this type of X-ray tube, means is interposed between the rotor and the rotary shaft, for reducing the difference of temperature between the stationary cylindrical housing and the rotor.

Abstract: An X-ray tube including a chamber enclosing an anode disc rotatable about an axis, and movable transversely with respect to that axis, the tube also enclosing an electron beam source for projecting electrons along a beam directed towards a planar surface of the anode disc. The beam source is disposed so as to direct its beam at an acute angle of incidence to the planar surface of the anode disc and produce X-rays which are thereupon reflected from the anode disc through a window in the chamber.

Abstract: A rotary anode comprising a basic body of carbon whose surface is provided with a pyrolytic graphite coating having a crystallographic layer structure. A metallic layer of high-melting temperature, in which X-rays are generated during operation in an X-ray tube, is provided on the body. The metallic layer and the pyrolytic graphite coating have a common contact face which cuts through the crystallographic layers in the pyrolytic graphite. Heat developed in the metallic layer is discharged through the face into the pyrolytic graphite layers.

Abstract: In a rotary anode X-ray tube, comprising an anode disc which is mounted on a rotary shaft and which comprises a basic body of graphite, the anode disc is subject to such loads during the operation of the X-ray tube that a connection between the disc and the shaft is liable to fracture if it consists of pressed and sintered graphite. In order to counteract fracturing, the basic body is connected to the shaft by a bushing of pyrolytic or microporous graphite. A pyrolytic graphite bushing may be formed by deposition from the gaseous phase in situ or on a mandril, and should have a radial direction of growth. Both materials have a high strength and, moreover, a lower thermal conductivity in the radial direction. As a result, not only is the strength improved, but the thermal loading of the shaft bearings is also reduced.

Abstract: The temperature of the anode disc of a rotary-anode X-ray tube is continuously determined by means of the method apparatus in accordance with the invention. When the temperature exceeds a first limit value, the power of the X-ray tube is reduced to a fraction (for example, 80%) of the otherwise permissible power. When a second limit value of the anode disc temperature is exceeded, exposures are completely inhibited. In the case of exposures which are performed in rapid succession with a comparatively low power, it may occur that the anode disc temperature does not reach the second limit value, but that the mean value of the applied electric power is so high that the bearing of the rotary anode, and possibly also the joint between the anode shaft and the rotor, is overloaded. Overloading is prevented by generating a bearing-temperature signal indicative of the rotary anode bearing temperature and comparing it with a third limit value.