The overall structure of the single bucket hydraulic excavator includes power unit, working unit, slewing mechanism, operating mechanism, transmission system, walking mechanism and auxiliary equipment.

The power unit of the single-bucket hydraulic excavator is mostly an upright multi-cylinder, water-cooled, one-hour power-calibrated diesel engine.

 The single bucket hydraulic excavator transmission system transmits the output power of the diesel engine to the working device, the slewing device and the walking mechanism. There are many types of hydraulic transmission systems for single-bucket hydraulic excavators, which are customarily classified according to the number of main pumps, the adjustment method of power and the number of circuits. There are single-pump or double-pump single-circuit quantitative system, double-pump double-circuit quantitative system, multi-pump multi-circuit quantitative system, double-pump double-circuit sub-power adjustable variable system, double-pump double-circuit full-power adjustable variable system, multi-pump multi-circuit quantitative system or variable mixing system and so on. According to the oil circulation mode, it is divided into open system and closed system. According to the oil supply mode, it is divided into series system and parallel system.

The basic structure of the crawler-type traveling mechanism of the single-bucket hydraulic excavator is roughly the same as that of other crawler-type mechanisms, but he mostly uses two hydraulic motors to drive one crawler each. Similar to the transmission of the rotary device, a high-speed low-torque motor or a low-speed high-torque motor can be used. The two hydraulic motors rotating in the same direction will drive in a straight line; if only one hydraulic motor is supplied with oil and the other hydraulic motor is braked, the excavator will turn around the crawler on the brake side. If there are two left and right hydraulic motors Reverse rotation, the excavation is about to turn in place.

Most of the single bucket hydraulic excavators use a combined structure crawler and a flat crawler - there is no obvious crawler, although the adhesion performance is poor, but it is strong and durable, and has little damage to the road surface. There are also three-thorn-type crawler belts, which have a larger grounding area and a shallower cutting depth of the crawler, which is suitable for excavator quarrying operations. After the implementation of standardization, it is stipulated that excavators should use rolled track shoes with light weight, high strength, simple structure and low price. The triangular track shoes specially designed for swampy land can reduce the ground pressure and improve the passing ability of the excavator on loose ground.

The driving wheels of the single-bucket hydraulic excavator are made of integral castings, which can correctly mesh with the crawler and drive smoothly. When the excavator is walking, the driving wheel should be located at the rear, and the tensioning section of the crawler is shorter to reduce the friction wear and power loss of the crawler.