Abstract: An inner and outer pressure difference within 0.3 MPa for disc cutters guarantees the effectiveness of their floating seals in high water pressure environments reaching 1.4 MPa. Thus, an adaptivebalancing structure should be designed and developed to reduce the pressure difference upon the disc cutter. The piston balance valve frequently leads to floating seal failure of the disc cutter due to rock slag blockage in highpressure environments or rapid wear of the Oring seal. Therefore, an adaptivebalancing rubber sleeve is designed to adaptively adjust the inner pressure of the disc cutter according to the outer pressure by elastic deformation of the airbag, realizing a dynamic pressure following the function of the disc cutter to the outer pressure. First, the adaptivebalancing mechanism of the rubber sleeve is studied based on theoretical analysis, and the performance evaluation method of the rubber sleeve is given based on combining simulation and theoretical analysis. Then, the optimal structural parameters are given based on the sensitivity analysis of the sleeve, the performance of an isodiametric rubber sleeve is experimentally studied, and the results show that the inner and outer pressure difference of the disc cutter is ~0.12 MPa under an input pressure of 0-0.6 MPa. Finally, the designed rubber sleeve was successfully applied to a shield tunneling project, achieving a good operation effect with disc cutters.

Key words: high water pressure, adaptivebalancing rubber sleeve, sealing, shield disc cutter