This auxiliary thrust cylinder series is the core drive element of the auxiliary propulsion system on double shield TBMs. Arranged in a circular array inside the tail shield, they react against the previously erected segmental lining ring to push the machine forward under specific conditions — such as when the main gripper is retracted, or the ground is too weak to provide adequate reaction force. The cylinders feature high thrust and ultra-long stroke (up to 2800 mm), and can work in coordination with, or independently from, the main thrust cylinders via zoned control. This enables continuous, safe advance through soft ground, faulted zones, and mixed-face conditions. With a high-rigidity structure, specialized high-pressure sealing, and integrated safety valve packages, they withstand sustained high-frequency heavy loads, intense vibration, and slurry exposure, ensuring stable, efficient tunneling operations.

This torque cylinder series is the core element for cutterhead torque transmission and attitude control on double shield TBMs. Arranged in an annular or V-configuration at the articulation joint between the front shield and the gripper shield, it performs two critical functions: smoothly transmitting the immense instantaneous reaction torque (tens of thousands of kN·m) generated during hard rock cutting to the gripper shield and segmental lining, and, through differential group extension/retraction, precisely adjusting the cutterhead and front shield attitude (tilting up/down, left/right) to steer the TBM along the designed alignment. Built with a high-strength anti-vibration structure, specialized high-pressure sealing, and integrated counterbalance valves, it withstands the high advance rates, severe impact, and mixed ground conditions of double shield TBMs, delivering zero deformation and zero leakage over long-distance tunnels while providing continuous, stable torque transfer and guidance.