What are the forms of the hydraulic system?

With the continuous development of technology, the hydraulic system components have gradually achieved standardization and serialization, and the comprehensive performance has been greatly improved.

The application of electronic technology, servo technology and other new technology and new technology makes the quality of hydraulic system rise to a new height. In recent years, it has contributed a lot to the development of national economy and military industry. Different classification standards, hydraulic system can be divided into different forms.

The number of pumps in the hydraulic system can be divided into three types: single pump system, double pump system and multi pump system.

According to the different forms of the hydraulic pump, it can be divided into quantitative pump system and variable pump system. The advantages of variable pump is within the scope of the regulation, can make full use of the power of the engine, but its structure and complex manufacturing process, high cost, can be divided into manual variables, as far as possible control variables, servo variable, pressure compensating variable and constant pressure variable, hydraulic variable etc.. [page]

According to the different fuel supply modes of the actuator, they can be divided into series system and parallel system. In the series system, the return oil of the last actuator is the oil of the next actuating element, and the pressure is reduced once per actuator.

In series system, when the main pump is controlled by the manifold valve, the movement of each actuator can be realized as long as the outlet pressure of the hydraulic pump is enough. But because the pressure of the actuator is superposed, the ability to overcome the external load will decrease with the increase of the number of the actuators.

In parallel system, when a hydraulic pump supplies oil to a group of actuators, the flow into each actuator is only part of the output flow of the hydraulic pump. Flow distribution varies with the load of different parts, actuator first into the load, only when the actuators are equal when the load can be achieved at the same time.

The quality of hydraulic transmission depends mainly on the performance of the hydraulic system, including the quality of the components used, the basic circuit is appropriate, etc..

The performance of the system, in addition to meeting the functional requirements, should be from the hydraulic system efficiency, power utilization, speed range and fine tuning characteristics, vibration and noise, as well as the installation and commissioning of the system is convenient and reliable.

Modern engineering machinery almost adopts the hydraulic system, and with the electronic system, computer control technology, become an important part of modern construction machinery.

According to the circulation mode of oil, the hydraulic system can be divided into open system and closed system.

Open system refers to the hydraulic pump oil absorption from the tank, the oil through a variety of control valves, drive hydraulic actuator, return oil, and then through the reversing valve back to the tank. The system structure is relatively simple, can play the role of heat dissipation and precipitation impurities, but the oil is often contact with the air, so that the air is easy to penetrate into the system, resulting in uneven movement of the mechanism and other consequences.

Open system fuel tank, self-priming performance of the oil pump is good. In the closed system, the inlet pipe of the hydraulic pump is directly connected with the return pipe of the actuating element, and the working fluid is closed in the pipeline of the system. Its compact structure, less contact with the air, the air is not easy to penetrate into the system, so the transmission is more stable.

The speed change and commutation of the working mechanism are realized by adjusting the variable mechanism of the pump or motor, avoiding the hydraulic impact and energy loss in the reversing process of the open system. But closed system is more complex than open system, because there is no oil tank, the heat and filtration conditions of the oil are poor.

In order to compensate for the leakage in the system, a small flow pump and tank are usually needed. As the single pole double acting cylinder large cavity flow range, in the work process will make use of power down, so the implementation of a closed system components for hydraulic motor.