The traveling mechanism of hydraulic excavator supports the quality of the whole machine and completes the walking task. Generally, two small torque or low-speed high torque hydraulic motors are used to drive one track respectively. If the left and right hydraulic motors rotate in the same direction, the excavator will travel in a straight line. If only one hydraulic motor is supplied with oil and the other hydraulic motor is braked, the hydraulic excavator will turn around the track on the braking side. If the left and right motors rotate in reverse, the hydraulic excavator will turn in place.
All parts of the traveling mechanism are installed on the integral traveling frame. The pressure oil output by the hydraulic pump enters the traveling hydraulic motor through the multi-channel directional valve and the central rotary joint. After the motor converts the pressure energy into output torque, it is transmitted to the driving wheel through the gear reducer, and finally the crawler is wound to realize the walking of the hydraulic excavator. The driving wheels of the hydraulic excavator are made of integral castings, which can mesh correctly with the crawler.
Most hydraulic excavators use combined track and flat track shoes without obvious shoe teeth. The flat track shoe has poor adhesion performance, but it is firm and durable and has little damage to the road surface. It is suitable for operation on hard rock ground or frequent transfer. Three shoe type crawler shoes can also be used, with large grounding area and shallow cutting depth of shoe teeth into soil, which is suitable for excavator quarrying operation. The triangular track shoe specially used in swamp can reduce the grounding specific pressure and improve the carrying capacity of excavator on soft ground. After standardization, it is stipulated that the excavator adopts rolled track shoes with light weight, high strength, simple structure and low price.
Each track shoe is equipped with a tensioning device to adjust the tightness of the track and reduce the vibration, noise, friction, wear and power loss of the track. At present, hydraulic excavators adopt hydraulic tensioning structure. The hydraulic cylinder is placed inside the buffer spring to reduce the overall dimension. When the excavator is walking, the driving wheel shall be located at the rear, which can shorten the tensioning section of the crawler and reduce the friction, wear and power consumption of the crawler.