US Patent 7558375 Stationary cathode in rotating frame x-ray tube

An x-ray tube includes a stationary base and a passage therein. The x-ray tube includes an anode frame having an anode positioned adjacent to a first end and having a neck at a second end, the neck extends into the passage, wherein the anode frame is configured to rotate about a longitudinal axis of the passage. A hermetic seal is positioned about the neck between the neck and the stationary base.