Hydraulic device is a driving device that uses hydraulic force to open, close or adjust valves. It consists of three parts: control, power and actuator. The control part consists of pressure control valve, flow control valve, directional control valve, etc. and electrical control system. The power part is composed of an electric motor or a pneumatic motor, a hydraulic pump, a fuel tank and other parts. It converts the effective power on the rotating shaft of the electric or pneumatic motor into fluid pressure energy for hydraulic transmission. There are two types of actuators, one is a hydraulic cylinder actuator, which realizes reciprocating linear motion; the other is a hydraulic motor actuator, which realizes rotary motion.
shortcoming:
Oil temperature is greatly affected by ambient temperature. Changes in oil temperature cause changes in oil viscosity, affecting operation;
The piping is troublesome and prone to leakage;
It is not suitable for occasions where various operations are performed on signals (such as signal amplification, memory, logical judgment, etc.).
advantage:
Simple structure, compact and small size;
The transmission is smooth and reliable;
A large output torque can be obtained;
The output torque can be accurately adjusted through the constant pressure relief valve, including the adjustment of opening and closing torque, and can even be directly reflected by the hydraulic instrument;
Easy to adjust speed;
In the event of a sudden power outage in an accident, the accumulator can still be used to perform one or several power operations. This has special significance for automatic emergency shut-off valves and wellhead blowout valves for long-distance pipelines.