Brushless drive system for a rotary anode arrangement of an x-ray tube

An X-ray tube comprising:

• an electron emitter;
• an evacuated X-ray tube housing;
• and
• a rotary anode arrangement, the rotary anode arrangement including
• a rotary anode, and
• a brushless drive system, the brushless drive system including
• a stator for generating a magnetic flux, the stator including a cylindrical stator yoke, an annular permanent magnet, and a coil unit, and
• a reluctance rotor, wherein the reluctance rotor has a cylindrical rotor yoke made of a soft-magnetic material, is free from magnetic sources, is configured to be connected to the rotary anode of the rotary anode arrangement, and is configured to be driven about an axis of rotation via the magnetic flux, wherein
• the rotary anode is non-rotatably connected to the reluctance rotor,
• the annular permanent magnet and the coil unit are axially spaced apart along the axis of rotation,
• the cylindrical stator yoke, the annular permanent magnet, the cylindrical rotor yoke and the coil unit form a magnetic circuit for guidance of the magnetic flux, the magnetic circuit configured such that, between the annular permanent magnet and the coil unit, an axial direction of the magnetic circuit in the cylindrical stator yoke and an axial direction of the magnetic circuit in the cylindrical rotor yoke have opposite signs, and
• the reluctance rotor and the electron emitter are arranged inside the evacuated X-ray tube housing and the stator is arranged outside the evacuated X-ray tube housing.