The travel device of an excavator is mainly composed of a frame, a travel mechanism, a crawler track along with its supporting wheel system, and a tensioning device, etc. The details are as follows:

Frame

It serves as the foundation of the travel device, usually adopting an X - shaped structure or an open - bottom "∏" - shaped cross - section design. Welded from a left longitudinal beam, a main frame, and a right longitudinal beam, it possesses sufficient strength and rigidity. Its functions are to support the weight of the excavator and transmit the travel power.

Travel Mechanism

It consists of a travel motor, a reducer, and their pipelines. The travel motor converts hydraulic energy into mechanical energy. After the reducer reduces the rotational speed and increases the torque, it drives the driving wheel to rotate, which in turn drives the crawler track to rotate, thereby enabling the excavator to move.

Crawler Track

As the component that directly contacts the ground, it is formed by connecting crawler shoes through connecting parts such as track chain pins, forming a continuous annular structure. Crawler shoes are usually made of rolled plates and come in forms such as single - ribbed, double - ribbed, and triple - ribbed. They can transmit the power of the travel driving device to the ground, realizing the movement and steering of the excavator.

Supporting Wheel System

It includes a driving wheel, an idler wheel, a track roller, and a top roller, commonly known as the "four wheels and one track". The driving wheel is usually located at the rear of the travel device, meshing with the track chain of the crawler to drive the crawler track to rotate. The idler wheel is used to guide the crawler track to rotate correctly, preventing it from deviating and derailing. The track roller transfers the weight of the excavator to the ground and rolls under the support of the crawler track, allowing the excavator to move on the ground. The top roller supports the crawler track from above, maintaining a certain tension of the crawler track and preventing it from sagging excessively.

Tensioning Device

Generally composed of an oil cylinder, an idler wheel frame, a support, a spring, etc., it pushes the piston and the push rod by injecting pressure grease, making the idler wheel move forward and backward. This realizes the tensioning and buffering of the crawler track, so as to keep the crawler track in a normal working state.

Central Swivel Joint

It is a hydraulic component that connects the oil circuit of the swivel platform and the chassis. It ensures that after the swivel platform rotates at any angle, the travel motor can still be normally supplied with oil, allowing the excavator to perform swivel actions while moving.