TUNNEL EXCAVATOR

PROBLEM TO BE SOLVED: To provide a tunnel excavator capable of rotating a cutter at a high speed by suppressing heat generation of a sealing member for preventing the incursion of earth and sand or muddy water to the inside from the outside in the tunnel excavator excavating a tunnel by driving the cutter. SOLUTION: The tunnel excavator includes the body section 5, a rotary member 15 rotating around the predetermined rotational center shaft CLI for driving the cutter and, at the same time, having the circular ring-shaped surface on a predetermined radius with the rotational center shaft CLI as the rotational center and the circular ring-shaped surface opposed to the circular ring-shaped surface of the rotational member 15, the center of the circular ring-shaped surface is provided so as to locate on the rotational center shaft CLI, an intermediate member 31 rotating at a rotational angle speed slower than the rotational member 15 in the same direction as the rotational member 15 around the rotational center shaft CLI and the sealing member 41 sealing between the rotational member 15 and the intermediate member 31 are included. COPYRIGHT: (C)2006,JPO&NCIPI