| 摘要 |
PURPOSE:To prevent damage due to the heat of a flexible joint from occurring, by making the maximum external diameter of a radiation shielder smaller than an inner diameter of an insertion hole by providing a shield part on an insulator of a motor case. CONSTITUTION:An insulator 5 is provided on the inside of a motor case 1. A nozzle 25 is provided on the tip of a flexible joint 6. A shield part 42 extending inward in a radiation direction is provided on the insulator 5. An inside edge of a radiation direction of a shield part 42 is positioned inward in a radiation direction of a radiation shielder 16 by a distance l from its extreme point. The maximum external diameter D of the radiation shielder 16 is made smaller than an inner diameter (d) of an insertion hole 2. Swing of the nozzle 25 can be performed without damaging the flexible joint 6 through heat in this manner. In addition to the above, incorporating work and replacing work are facilitated. |
