ROTARY ANODE X-RAY TUBE

PURPOSE:To reduce the variation of clearance in a ball bearing fixing position owing to a thermal expansion, by arranging a saucer type spring at the position where inner rings of the bearings and a cylindrical member to define the interval of the inner rings are set to a rotary shaft. CONSTITUTION:Inner rings of ball bearings 4a and 4b, and a cylindrical member 7 are set to a rotary shaft 3, and they are connected integrally by a nut 14 through a washer 12 and a saucer type spring 13 with a relatively large spring rating. By setting the saucer spring 13 in a sufficiently compressed condition beforehand, a pressure from a strong stability of the saucer spring 13 moves the inner ring of the ball bearing 4b side, pressing the cylindrical member 7 and the inner ring of the other side ball bearing 4a, and squeezing them to a larger diameter portion 15 of the rotary shaft constantly. Therefore, the clearance produced between the inner ring of the ball bearing 4a or 4b and the cylindrical member 7 can be prevented perfectly.