How does the hydraulic control system work
The hydraulic servo control system is a feedback control system composed of hydraulic power components as the driving device. In such a system, the output (displacement, velocity, force, etc.) can automatically, quickly and accurately reproduce the variation of the input amount. At the same time, the input signal is also power amplified and therefore also a power amplifying device.
The hydraulic pump is the energy source of the system. It supplies oil to the system at a constant pressure, and the supply pressure is set by the relief valve. The hydraulic power unit consists of a four-sided slide valve and a hydraulic cylinder. The slide valve is a conversion amplifying element that converts the input mechanical signal (spool displacement) into a hydraulic signal (flow, pressure) output and is amplified by power. The hydraulic cylinder is the actuator, the input is the flow of the pressurized oil, and the output is the speed of movement (or displacement). The spool valve body and the cylinder block are rigidly coupled to form a feedback loop. Therefore, this is a closed loop control system.