QDY15 Series Servo Valve

Description
QDY15 series double nozzle flapper servo valve is a key control part of the electro-hydraulic servo control system, acting on electro-hydraulic conversion and power amplification. It consists of electro-mechanical conversion, power amplifier, feedback.

Advantages
1. This servo valve has great performance on fast dynamic response, pressure sensitivity and linearity, small zero drift, low required input. power.
2. Force feedback servo valve adopts stainless steel shell, with the characters of compact structure, light weight.
3. It is allowed to select the 5th oil port for controlling the pilot valve separately.
4. Our self-developed servo valves have been widely used in metallurgy, aerospace, shipbuilding, automobile, textile and printing industry.

Component of Double Nozzle Flapper Servo Valve
Electro-hydraulic servo valve is a closed-loop control system, which generally consists of electro-mechanical conversion, power amplifier, feedback.

1. Electro-mechanical conversion parts: in nozzle flapper servo valve, electro-mechanical conversion parts is a torque motor, the principle of operation is to convert the current of input coil swinging into the mechanical energy of the armature.











2. Power amplifier section: power amplifier is convert the input mechanical energy of the swing armature into the hydraulic energy of pressure and flow. In QDY series electrical feedback valve, the power amplifier is mostly achieved by flapper-structure.










3. Feedback: this part is to feedback the output pressure or flow to the preceding stage as the displacement, force or other forms. Due to this feedback mechanism, the servo valve itself is a closed-loop control system. QDY series servo valve is force feedback servo valve, to achieve the feedback function by bezel components.









Parameters of Double Nozzle Flapper Servo Valve

Type			QDY15
Supply oil pressure range		Mpa	1.5 to 25
Rated supply oil pressure		Mpa	21
Rated flow QN [L/min] (at valve pressure drop of 7MPa)		L/min	4, 10, 20, 40
Rated current In		mA	30, 40
Hysteresis		%	≤3
Resolution		%	≤0.5
Non linearity		%	≤±10
Asymmetry		%	≤±10
Pressure gain		%	＞30
Internal leakage		L/min	≤1.5
Bias		%	≤±3
Zero drift of supply oil pressure(80 to 110% Ps)		%	≤±2
Zero drift of return oil pressure(0 to 20% Ps)		%	≤±2
Zero drift in temperature(-30 to +150)		%	≤±4
Frequency	Amplitude frequency width (-3db)	Hz	＞50
	Phase frequency width (-90°)	Hz	＞60
Work temperature		℃	-40 to +100
Net weight		Kg	0.8