| 摘要 |
PROBLEM TO BE SOLVED: To excavate a noncircular excavation cross section, by providing circular and noncircular loci in the same center, while reducing rotational run-out and vibration of a driving system and reducing the driving system and design cost. SOLUTION: This rotating mechanism has a central shaft 31 rotatably arranged around the predetermined fixed center line O, a main blade member 211 (a main excavation cutter 21) extendedly arranged in the radial outward direction of the central shaft 31, a rotary shaft 33 rotatably arranged to the main blade member 211 around the moving center line P parallel to the fixed center line O, a sub-blade member 221 (a sub-excavation cutter 22) extending in the radial outward direction of the rotary shaft 33 and arranged in a mode of changing a projecting dimension from the tip of the main blade member 211 in response to rotation of the rotary shaft 33, a driving part rotatingly driving the central shaft 31, and a rotation transmitting mechanism 34 transmitting rotation of the central shaft 31 as predetermined rotation of the rotary shaft 33. COPYRIGHT: (C)2007,JPO&INPIT |
