| 摘要 |
PURPOSE:To maintain the balance with high accuracy in rotation by setting the mounting position of a rotor in an induction motor to a rotating shaft to the intermediate position of ball bearings where the center of gravity of an overall rotating portion accords to the intermediate position of ball bearings within a vacuum-sealed bearing portion. CONSTITUTION:An anode target 4 is supported on the end portion of a rotating shaft 118, consisting of an insulator with large heat conductivity, which has a fluid refrigerant passage 134 in the inside, and the shaft 118 can be rotated through a housing 110 by means of a vacuum-sealed bearing portion consisting of ball bearings 109, 109, a magnet 11, pole pieces 112, 113 and a magnetic fluid 116. Further, the rotor 128 of an induction motor 7 is mounted on the shaft 118, and the position is set to the intermediate position of ball bearings where the center of gravity of an overall rotating portion including the target 4 accords to the intermediate position of the ball bearings 109, 109. Accordingly, it is possible to reduce oscillation and noise, and it is possible to improve the cooling performance of the target 4 to increase X-ray output volume. |
