Bearing and rotary anode X-ray tube employing the bearing

摘要

A rotary anode X-ray tube comprises a cathode for emitting electrons in a vacuum vessel, an anode target with which the electrons emitted from the cathode collide to generate X-rays, a rotor fixed integrally with the anode target, and a plurality of bearings for rotatably supporting the anode target. Frictional surfaces of at least one of the bearings that is located in the vicinity of the anode target are coated with lubricant that demonstrates low vapor pressure at high temperatures. Main component of the lubricant is one of tin, aluminum and indium. Mother material of at least one of the bearings is ceramics.