VERY SLOW SPEED ROTATION MECHANISM FOR CUTTER IN TUNNEL BORING MACHINE

PROBLEM TO BE SOLVED: To provide a very slow speed rotation mechanism for cutter in a tunnel boring machine, in which a speed reduction gear apt to enlarge the diameter of the tunnel boring machine is made unnecessary, the diameter of the tunnel boring machine can be smaller than that of existing machines, and a range of objects to be excavated is widened, thus improving efficiency of boring work.SOLUTION: A very slow speed rotation mechanism for cutter can be used for a tunnel boring machine equipped with a cutter comprising a body part 2, a cutter head part 3 rotatable with regard to the body part 2, and a rotating shaft 4 mounted to the cutter head 3. The very slow speed rotation mechanism for cutter comprises a pinion gear 9 provided on the rotating shaft 4 and a very slow speed jack 11 having a rack 10 engaged with the pinion gear 9.