| 摘要 |
PURPOSE:To secure the sealing function of a cutter sealing device by a method in which a lubricating oil is injected into each pressure chamber to produce back pressures against the front pressures of each front-stage seal, and the lubricating oil of lower pressures than the front pressure of the front-stage seal is injected only into the final stage pressure chamber. CONSTITUTION:Several-stage seals 21 - 25 are set between a shield body 1 and a cutter wheel 2. A lubricating oil is injected from the first injector 40 into pressure chambers 31 - 33 formed between the seals 21 - 24 other than the final stage one in such a way as to produce back pressures against the front pressures of each front-stage seal. Also, the lubricating oil of lower pressures than the front pressure of the front-stage seal 24 is injected from the second injector 50 into the pressure chamber 34 formed between the final stage seal 25 and the front-stage seal 24. The pressure to be received by the final stage seal 25 free of back pressure can thus be kept lower than the facing water pressure, and the whole sealing function of the cutter sealer under high earth pressure and high water pressure can be secured. |
