Abstract: In an X-ray device which includes an X-ray tube (12) provided with means (15, 22, 23) for influencing the electron flow through the X-ray tube (12), a control voltage for the means for influencing the electron flow is customarily generated by means of a complex circuit which, because of its size, is not suitable to be accommodated within the protective tube housing. This has the drawback that the control voltage for the X-ray tube, usually of high voltage potential, must be supplied additionally to the high-voltage supply. Therefore, it is desirable to realize a simple generation means the control voltage which is suitable for accommodation in the protective tube housing. To this end, the invention proposes a piezoelectric transformer (21, 24, 25) for generating the control voltage for the X-ray tube. The invention also relates to a piezoelectric transformer which is particularly suitable for generating such a control voltage.

Abstract: The invention relates to a rotary anode X-ray tube having a sliding bearing and a further bearing system. The further bearing system, preferably a magnetic bearing, is constructed so that it can absorb substantially entirely the axial and radial bearing forces, while the sliding bearing, which is preferably constructed as a spiral groove bearing with liquid metal lubrication, is shaped so that it absorbs the bearing forces only for a small fraction. It therefore has only a low friction, but it permits the supply of the anode current and especially an effective cooling of the anode disk.

Abstract: In an X-ray tube comprising a metal housing portion and an electrode which can be connected to a positive high voltage with respect thereto and which is mounted on a ceramic insulator portion, a conical insulator portion is enclosed by a wall portion, at least the inner surface of which has an insulating effect. A screening sleeve which electrically screens the connection between the insulator portion and the electrode projects into a recess in the wall portion.