The torque arm hydraulic cylinder is an essential part of the TBM's thrust and steering system.
It is responsible for controlling the rotation and torque applied to the cutterhead, the front-facing cutting component of the TBM. By regulating the torque arm's movement, the hydraulic cylinder ensures precise and controlled excavation.
Size and Capacity:
The specifications of the torque arm hydraulic cylinder can vary depending on the TBM's size and design. However, these cylinders are typically robust and designed to withstand enormous forces. They can have a bore diameter ranging from a few inches to several feet, and their stroke length can extend up to several meters. The exact size and capacity are determined by the specific requirements of the TBM project.
Pressure and Hydraulic System:
Torque arm hydraulic cylinders operate under extremely high pressure to provide the necessary force for cutting through rock or soil. The hydraulic system that powers these cylinders typically utilizes a hydraulic fluid, such as oil, which is pressurized by powerful hydraulic pumps. The pressure can range from hundreds to thousands of psi (pounds per square inch) to ensure the required force is generated.
Materials and Durability:
Given the challenging operating conditions in tunnels, torque arm hydraulic cylinders are constructed from durable materials. They are often made from high-strength steel or other robust alloys that can withstand heavy loads, corrosion, and abrasion. Special coatings and treatments may be applied to enhance their longevity.
Precision and Control:
One of the key features of the torque arm hydraulic cylinder is its precise control.
The hydraulic system allows for accurate adjustments in the force applied to the cutterhead. This level of control is essential for maintaining the tunnel's alignment and preventing deviations during excavation.
Sealing and Lubrication:
To ensure reliable operation and prevent hydraulic fluid leaks, torque arm hydraulic cylinders are equipped with high-quality seals. These seals are designed to withstand the high pressure and continuous movement associated with TBM operation. Lubrication systems are also integrated to reduce friction and wear on moving components.
Monitoring and Maintenance:
Proper monitoring and maintenance of the torque arm hydraulic cylinder are critical to TBM performance and safety. Sensors and instruments may be installed to measure pressure, temperature, and other vital parameters. Regular inspections and maintenance procedures, including seal replacement and fluid changes, are essential to prevent downtime and ensure the cylinder's longevity.