Magnetic lift device for an x-ray tube

An x-ray tube, comprising:

• an evacuated enclosure;
• a cathode disposed within the evacuated enclosure;
• an anode disposed within the evacuated enclosure configured to receive electrons emitted by the cathode;
• a bearing assembly configured to stabilize the anode during a rotation of the anode;
• a stator configured to generate electromagnetic fields;
• a rotor sleeve coupled to the anode, the rotor sleeve is configured to rotate in response to applied electromagnetic fields from the stator;
• a ferromagnetic shaft coupled to the anode and having an axis of rotation that is substantially collinear with an axis of rotation of the anode;
• and
• a lift electromagnet configured to apply a magnetic force to the ferromagnetic shaft in a radial direction, wherein pole ends of the lift electromagnet extend through an envelope of the evacuated enclosure.

A method of controlling a lift electromagnet in an anode assembly of an x-ray tube, the method comprising:

• determining a loading force acting on a bearing assembly of an anode assembly in a radial direction;
• generating an electrical lift signal for a lift electromagnet to oppose the loading force, the lift electromagnet including pole ends that extend through an envelope of an evacuated enclosure of the x-ray tube;
• and
• generating a magnetic counter force by the lift electromagnet on a ferromagnetic shaft coupled to the bearing assembly, the magnetic counter force is generated from the electrical lift signal and is in a substantially opposite direction as the loading force.