| 摘要 |
PROBLEM TO BE SOLVED: To reduce manufacturing costs and rotate a sealing element smoothly. SOLUTION: A shield excavator has a sealing element 3, which is rotatably installed inside the front end of a cylindrical main body 1 having openings 1b in its front end and in its side face, with the front end of the sealing element 3 being able to face the opening 1b, and has a slave machine 15 stored in the sealing element 3. The sealing element 3 comprises a cylindrical inner shell having an opening at its front end and an outer shell which consists of a first projecting face part 6a provided on the outer peripheral surface of the inner shell and so formed as to extend along the inner peripheral wall of the main body 1 when the front end of the sealing element 3 is opposed to the opening in the front end of the main body 1, and a second projecting face part 6b disposed to cross the first projecting face part 6a and so formed as to extend along the interior wall of the main body 1 while the front end of the sealing element 3 is opposed to the opening in the side face of the main body 1. Packing 11 which can touch and leave the first or second projecting face part 6a or 6b by expanding and contracting radially is provided on the inner peripheral wall of the main body 1. |
