Electro-Hydraulic Servo Valve

CSDY1 CSDY2 electro-hydraulic servo valve is the latest product among the electro-hydraulic servo valves in the world. It adopts dry-type torque motor, wholly welded, jet pipe and main slide valve which are flow control valves with high capability in 2-way direction. It can receive weak electric signal and convert the signal into hydraulic power amplification. The output flow is proportional to the control electric signal.

Characteristics: (1)Robust structure. The valves can withstand class I vibration, class I shock and impact of 400g acceleration. (2)Stable zero. The stability of zero is better than that of dual jet plate valve and the valves are more reliable. (3)high resolution. (4)strong capability against pollution. They can use 7-8 hydraulic oil of 7-8 NAS1638. (5)Long working life. They can be used for more than 107 times. ( about 5000 hours per time). (6)High control accuracy.

The valves can be used in high accuracy electric hydraulic control systems in various fields, like shipbuilding industry, aerospace and aeronautic industry, heavy industry, light and textile industry, as well as in the mechanical hydraulic servo system for agriculture machinery.

Main Technical Index
1. Type CSDY1-2481015203040(CSDY2-6080100120)
2. Rated current ± 8mA
3. Resistance of coil 1000± 100Ω
4. Insulation resistance >50MΩ
5. Rated pressure 206× 105Pa
6. Operation pressure (20~309)× 105Pa
7. Rated flow Qn2481015203040L/min (Model CSDY2: 6080100120)
8. Hysterisis < 3%
9. Linerity < 7.5%
10. Symmetry: 10%

11. Flow consumption at static state < 0.45+3%Qn
12. Pressure gain >30%PS/1%
13. Resolution < 0.25%
14. Zero offset < 2%
15. Zero drift 2%
16. Frequency response (-3dB)>70Hz (-90° )>90Hz
17. Temperature range -40C~+85C
18. Fluid dynamic viscosity 10-100cst
19. Filter accuracy for system 10~20u

Operation Principle
High-pressure oil gets out in 2 ways, one gets into jet pipe nozzle through fuel filter, and the other gets into gateway which consists with spool and valve pocket. There are 2 conditions. One is without signal current; The valve will stay at zero and without flow output. One is with control signal current, jet pipe nozzle will move (set as clockwise). In the mean time, the pressure of Left cavity goes up, the pressure of right cavity goes down, and spool moves right under pressure, whose oil-way is PS-A-1 and load -2-C-P. When spool moves right, feedback moment will feedback to jet-flow pipe which makes both cavities' pressure achieve balance and output regime flow. But if the controlling signal electric current reverses, the output of servo valve will reverse too.