| 摘要 |
PURPOSE:To provide a rotating anode X-ray tube device of greatly enhanced reliability, by using magnetic bearings so that a target for generating a large capacity of X-rays is rotatably supported out of contact with the bearings. CONSTITUTION:The rotors 114, 115 of magnetic thrust bearings are provided inside their stators 112, 113. An electric insulator 137 is shrink-fitted in the rotor 114 so that the insulator extends through the rotor. A metal plate 138 of molybdenum or the like is conjoined to the end face 137a of the electric insulator 137. An anode target 4 for generating X-rays is secured to the metal plate 138 by bolts 139. The rotors 114, 115 of the magnetic bearings are both kept at the ground potential by electricity supply diodes 124, 125 and other electricity supply diodes 128, 129 whose characteristics are inverse to those of the diodes 124, 125, so that the rotors have substantially the same potential as vacuum walls 102, 103 in the magnetic bearings. For that reason, the clearances between the rotors 114, 115 and the stators 112, 113 can be kept small enough to make the stiffness of each magnetic bearing very high. |
