Servo hydraulics? Do you understand?

Maanshan Xiyuan Machinery Technology Co., Ltd. has maintained excellent results in the technical level and sales of folding and shearing machine tools for many years. We have strong technical force, advanced processing equipment, scientific quality management and strong research and development capabilities. Our products are NC plate bending machine, Hydraulic guillotine shear, NC press brake. Today, I will share with you the advantages and disadvantages of servo hydraulic stations.

The servo hydraulic station started in 1950, and has made great progress over the years. Nowadays, hydraulic control systems are basically used more widely in various industries. Let's take a look at the advantages and disadvantages of the servo hydraulic station today, which is conducive to convenient and quick use in the future.

Advantage:

(1) The action of the hydraulic system actuator is fast and the commutation is fast. As far as the flow-velocity transfer function is concerned, most of it is an oscillation stage with a very large natural frequency, but with the increase of flow and the best matching of parameters, the natural frequency can be expanded to be compared with the natural frequency of the electro-hydraulic servo valve. The natural frequency of the electro-hydraulic servo valve is generally above 100HZ, so the frequency response of the hydraulic system actuator is very fast, and it is easy to quickly start, brake and commutate. Compared to electro mechanical system actuators, the natural frequency is generally higher.

(2) The volume and weight of hydraulic system actuators are much smaller than those of electromechanical actuators with the same output power. Due to the increase in the volume and weight of hydraulic system actuators (such as valves, hydraulic cylinders or motors) with the increase in output power, the increase in volume and weight is much slower than that of electromechanical actuators, mainly because the front mainly relies on expanding liquid flow and pressure to increase output power. , although the volume and weight of the power mechanism will increase, but high-strength and light metal materials can be used to reduce the volume and weight.

(3) The actuator of the hydraulic system has stable transmission and strong anti-interference, especially in low-speed gears, while the propagation stability of the electromechanical system is weak, and it is easily affected by various external disturbances such as electromagnetic waves.

(4) The hydraulic system actuator has a wide range of speed regulation and high output power gain.

Disadvantages:

(1) The signal transmission speed of the hydraulic system is relatively slow, and it is not easy to carry out correction, while the electrical signal transmits information at the speed of light, and is easy to synthesize and correct. However, although the electro-hydraulic servo system uses an electrical signal before the output power stage, there is no such shortcoming, and in a sense, this type of system has the advantages of both electric and hydraulic servos.

(2) The structure of the servo hydraulic station is complex and the machining accuracy is high, so the cost is high.

(3) The bulk modulus of the liquid varies with the temperature and the air content mixed into the oil. There is a significant impact on system performance when temperature changes. In contrast, the temperature has little effect on the bulk modulus of gas, so it has little effect on the working performance of the pneumatic control system.

The temperature has a great influence on the viscosity of the liquid, and the friction loss increases at low temperature; the leakage increases at high temperature, and cavitation is easy to occur.

(4) Oil leakage is the weak point of the hydraulic system, which not only pollutes the environment, but also easily causes fire. Hydraulic fluid is susceptible to contamination and can cause actuator blockages.