| 摘要 |
PROBLEM TO BE SOLVED: To provide an underground boring machine suitable for the excavation of a small-diameter tunnel. SOLUTION: This underground boring machine is constituted so as to be provided with a planetary gear device 17 comprising a cutter driving device 4 with a single drive motor 6, an outside driving shaft 9 turnably supported and drivenly connected to the drive motor 6, an inside fixing shaft 13 penetrated inside the outside driving shaft 9 and unturnably fixed thereto, a planetary frame 18 integrally and turnably fitted to the outside driving shaft 9, a sun gear 21 housed inside the planetary frame 18 and fixed to the inside fixing shaft 13, a planetary gear 22 turnably iournaled inside the planetary frame 18 and engaged with the sun gear 21, and a supporting shaft gear 25 turnably housed inside the planetary frame 18 and engaged with the planetary gear 22; a cutter supporting shaft 26 fitted to the supporting shaft gear 25 and turnably supported by the planetary frame 18, and a cutter 31 having a cutter frame 32 turnably and integrally fitted to the cutter supporting shaft 26. |
