| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method wherein a lubricant remaining in a gear box can be removed at low cost without burning it. SOLUTION: In the method, a shield excavator having a construction such that a lubricant pressurized by a grease pump 11 is filled into a gear box 6 interconnecting a cutter motor 5 provided in a shield and a drive member to transmit a drive force to a cutter wheel 2 is used. In this case, when the excavator reaches a predetermined excavation position, the cutter wheel 2 is driven idly and a lubricant into which a small amount of a dissolving agent is mixed is supplied from a grease pump 11 and then a mixing ratio of the agent is increased to turn the lubricant in the gear box 6 into a liquid form and at the same time, the lubricant is caused to flow down out of the box 6 so that the lubricant in the form of liquid is drawn and removed. |
