Very often we will find the drive sprocket wheel under the name of the drive star. It is a profiled wheel with teeth that mesh with the track. In the case of tracked vehicles, the motor-driven gear may be located at the front or rear of the vehicle, or in some cases both. There may also be a third rack, raised, to drive the track. In fact, it is difficult to imagine a properly functioning crawler undercarriage without a properly functioning drive sprocket wheel and idler. The drive sprocket wheels are made of high-quality steel and are subjected to hardening. This process aims to obtain the maximum possible abrasion resistance.
It is a mechanism that allows vehicles to move using tracks. They increase the contact surface of the vehicle with the ground – reduce the unit pressure and improve the road passability. The caterpillars are of course used in excavators, but also in tanks, bulldozers and armored personnel carriers. In general, tracks are used on machines that maneuver over unrestrained surfaces. The basic track system consists of an endless track belt which surrounds the load wheels. Most designs include a track drive wheel and a guide wheel separately. Additionally, support rollers as well as a tension wheel can be used. The figure on the right shows a diagram of an example of a caterpillar track system:
1. track roller
2. carrier roller
3. front idler
5. track link
6. final drive
A vehicle with tracks is driven by a rotating drive wheel. This wheel, meshing with the belt, puts it in motion. The part of the track located above the wheels moves in the direction of the vehicle’s movement, and the lower part cuts along the ground creating a paved track for the road wheels moving along it with the entire vehicle. The undoubted advantage of the crawler track system is the improvement of the vehicle’s ability to operate in difficult terrain conditions. All thanks to the aforementioned reduced pressure unit, which reduces the sink and the slip of the vehicle.