Abstract:

To solve the technical problems of the main drive highpressure sealing of tunnel boring machines and provide guidance for the parameter design of the sealing system under highpressure conditions, a 5 m main drive sealing test platform is established. Then, the feasibility of the sealing test platform is validated using a combination of static and dynamic tests. Moreover, the influences of rotating speed, pressure, and cooling water flow on the temperature rise of two highpressure sealing systems of lipshape and polyurethane seals are investigated. The results indicate the following: (1) In the static test, the highpressure sealing system is pressurized sequentially to 2 MPa and then becomes stable, validating the highpressure bearing capability of the two sealing systems. (2) The dynamic experiment results of the lipshape and polyurethane sealing systems indicate that a high rotating speed will reduce the stability of seal pressure, and the influence is more significant under high pressure. (3) The rotating speed significantly influences seal temperature; moreover, there is a positive correlation with seal temperature rise. The higher the seal pressure, the greater the seal temperature rise. (4)  A rotating speed of 1.5 r/min can balance the requirement of stability and calorific values of the two sealing systems. The cooling water flow of the polyurethane seal system is better controlled at 50 L/min.

Key words: tunnel boring machines, main drive seal, lipshape seal, polyurethane seal, seal test platform