The structure and working principle of the bucket excavator
The bucket excavator is mainly composed of the engine, the hydraulic system, the working device, the walking device and the electrical control. The hydraulic system consists of a hydraulic pump, a control valve, a hydraulic cylinder, a hydraulic motor, a pipeline and an oil tank. The electrical control system includes the monitoring disk, the engine control system, the pump control system, the various kinds of sensors, the electromagnetic valves and so on.
The bucket excavator is generally composed of three parts, the working device, the rotary device and the walking device. According to its structure and usage, it can be divided into: crawler, tyre, walking, hydraulic, semi hydraulic, full rotary, non full rotary, universal, special, articulated, telescopic and other types.
The working device is the device to complete the mining task directly. It is hinged by three parts, such as the moving arm, the bucket rod, the bucket and so on. The starting and falling of the movable arm, the expansion of the bucket rod and the rotation of the bucket are controlled by the reciprocating double acting hydraulic cylinder. In order to meet the needs of various construction operations, hydraulic excavators can be equipped with various kinds of working devices, such as digging, lifting, loading, leveling, clamping, pushing and hammer hammers.
The revolving and walking device is the body of a hydraulic excavator, and the upper part of the turntable is equipped with a power device and a transmission system. The engine is the power source of the hydraulic excavator. Most of the diesel will be used in the convenient site, and the motor can be used.
The hydraulic transmission system transfers the power of the engine to the hydraulic motor, hydraulic cylinder and other executive elements through the hydraulic pump, so as to promote the operation of the device and complete various operations. The PV-200 hydraulic excavator, which is used more in the construction site, is taken as an example. The machine uses an improved open central load sensing system (OLSS). The system uses the method of controlling the swashplate angle (output flow) of the swash plate variable piston pump, which reduces the power output of the engine and reduces fuel consumption, which is an energy saving system.
The characteristics of this hydraulic system are: constant torque control, keeping the torque of the hydraulic pump unchanged, and load control, which can reduce the unloading loss of the operation time. The oil volume control can reduce the output flow of the hydraulic pump and reduce the power loss when the neutral and micro control are controlled.