Normal pressure tunnel boring machine is a kind of tunnel boring equipment, which is used in underground tunnels, mines and other projects. It usually includes a shield body and a main drive arranged in the shield body. It can operate while keeping the working face pressure the same as the atmospheric pressure on the ground. The characteristic of this tunnel boring machine is that its design allows operators to work in a normal atmospheric pressure environment, thus avoiding the impact of high pressure environment on human health.
Take a normal pressure cutterhead tunnel boring machine as an example. Its main drive includes a drive box, the middle part of which is a central channel that runs through the front and back, and also includes a drive device fixed relative to the drive box, which is used to provide power for the rotation of the corresponding cutterhead. The rear end of the drive box that encloses the central channel is sealed with a sealing plate, which blocks the rear end of the central channel to enclose the central cabin, and the central part of the sealing plate is provided with a central swivel joint installation hole for installing the central swivel joint.
Such a structure enables the center cabin to be integrated on the main drive. Compared with the method of nesting the center cabin shell protruding backward in the main drive and using its inner cavity to form the center cabin, the structure of integrating the center cabin with the main drive can further miniaturize the radial size of the main drive while ensuring the radial size of the center cabin, thereby miniaturizing the radial size of the tunnel boring machine.
In addition, a single gate for normal pressure tool change is also used in the normal pressure tool change technology of the tunnel boring machine. For example, a single gate for normal pressure tool change of the tunnel boring machine includes a front cover and a rear cover that are fixedly connected, and a cavity is formed between the two. A sealing component is arranged at the edge of the cavity, and a knife plate is arranged in the cavity. A driving device (such as a cylinder) that can drive the knife plate to reciprocate inside and outside the cavity is arranged on the connecting side of the front cover and the rear cover, thereby realizing the opening and closing of the gate. This gate is not only compact in structure, but also convenient and safe to operate.
Normal pressure tunnel boring machines are suitable for tunnel excavation under various geological conditions, especially in urban subways, railway tunnels, water conservancy projects and other fields. Because it can operate under normal pressure, it greatly improves the work efficiency and safety of workers, and also reduces the impact on workers' health. With the continuous advancement and innovation of technology, the performance and automation level of normal pressure tunnel boring machines are constantly improving, making it an indispensable and important equipment in modern underground engineering.
Different types of normal pressure tunnel boring machines may have some differences in structure and function, and the specific characteristics and advantages will vary depending on the design and application scenarios. If you want to know more about the details of normal pressure tunnel boring machines, you can consult our professional engineering and technical personnel.