Hydraulic servo system
Servo systems are closed-loop control systems. In many industrial applications it is often required to convert small mechanical motions into a different motions with increased force. Hydraulic systems are particularly suitable for applications where large actuation forces are required. The RT 710 unit allows the operation of a hydraulic servo system to be investigated in detail. A carriage with a mass of 50kg is moved by a hydraulic cylinder. Additional springs and an adjustable hydraulic damper permit static and dynamic loads to be simulated. The displacement of the carriage is established using a potentiometric position sensor and compared against the reference variable. The control deviation is processed in a separate servo amplifier. Depending on the direction of the deviation, a control valve is activated in forward or reverse direction, which in turn produces a corresponding movement of the hydraulic cylinder and the carriage.
All variables can also be tapped as voltage signals. The GUNT software contains among other features an oscilloscope, a frequency generator and a voltmeter. In dynamic processes, for example, the displacement signal can be represented on the oscilloscope. Via the software, the reference variable can also be applied to the system in the form of a voltage. This implies that, with the frequency generator, dynamic tests can be performed and the frequency response recorded.
The trainer is a mobile unit. Measuring devices can be housed in the built-under cabinet unit.
- complete model of a hydraulic servo control loop
- position control with adjustable load conditions
- hydraulic cylinder with directly mounted control valve
- vibration-damped mounting
- electronic servo amplifier
- GUNT software including oscilloscope and frequency generator
Hydraulic unit
- power output: 1,1kW
- flow rate: 4,3L/min
- head: 1500m
- tank capacity: 10L
Hydraulic accumulator capacity: 2L
Accumulator charging valve: max. 40L/min
Hydraulic cylinder
- piston diameter: d=40mm
- stroke: 150mm
- mass moved: 50kg
Control valve NG6
- nominal flow rate: 24L/min
- activation: ±10V
Potentiometric position sensor
- measuring range: 150mm
- output: 0 …10V
400V, 50Hz, 3 phases
400V, 60Hz, 3 phases
230V, 60Hz, 3 phases; UL/CSA optional
- self-contained training system of a complete hydraulic position control loop with adjustable loading conditions
- oil circuit with hydraulic unit, hydraulic accumulator, 2 manometers, control valve and hydraulic cylinder to move a weighted carriage
- operation of the electromagnetic control valve for position control by servo amplifier
- servo amplifier with adjustable
gain - all control variables available as voltage signals
- potentiometric displacement sensor
- adjustable load conditions on carriage using 2 springs with hand wheel and adjustable damping
- low-friction ball bearing-mounted carriage
- mobile steel profile trolley with built-under unit
- GUNT software for data acquisition via USB under Windows 7, 8.1, 10
- familiarisation with the mode of operation of a hydraulic position control loop with adjustable load conditions
- reading and understanding circuit diagrams
- replacing springs and adjusting the damper
- influence of load and system pressure on control accuracy
- influence of the amplifier constants on the stability of the closed control loop
- recording the frequency response