Rotary anode type X-ray tube having a jacket to prevent lubricant from being scattered

A rotary anode type X-ray tube comprising:

• an anode target,
• a rotary structure, said rotary structure comprising a rotating shaft to which the anode target is fixed;
• a stationary structure coaxially arranged with the rotary structure with a clearance opening between said rotary structure and said stationary structure,
• a slide bearing section provided between the rotary structure and the stationary structure and having spiral grooves;
• a liquid metal lubricant applied to the slide bearing section between the rotary structure and the stationary structure;
• a vacuum envelope defining a space in which the anode target, the rotary structure, the stationary structure, the slide bearing section and the liquid metal lubricant are arranged;
• enclosing means, having a hollow space communicating with the clearance opening, for enclosing the clearance opening to prevent the lubricant from being scattered into the vacuum space from the hollow space;
• wherein one of the rotary structure and the stationary structure is of cylindrical shape having a wall section, a closed bottom section and an open top section so as to receive another of the rotary structure and the stationary structure, and the other of the rotary structure and the stationary structure is shaped like a column and fitted within the one of the rotary structure and the stationary structure.