QDY14 Series Servo Valve

Description
Electronic throttling control valve is a key control part of the electro-hydraulic servo control system, acting on electro-hydraulic conversion and power amplification.
To be specific, it can receive the electrical signal passed by system directly, and convert it into a load flow or pressure signal which is polarized, proportional and can control the electro-hydraulic servo valve, so that the system will output hydraulic power to drive the corresponding executive bodies. The performance and reliability will directly affect the performance and reliability of the entire system, so it is the core of electro-hydraulic servo-control system.

Component of QDY14 Servo Valve
Electronic throttling control 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 Electronic Throttling Control Valve

Type			QDY14
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		mA	30, 40
Hysteresis		%	≤3
Resolution		%	≤0.5
Non linearity		%	≤±8
Asymmetry		%	≤±10
Pressure gain		%	＞30
Internal leakage		L/min	≤1.3
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	60 to 100
	Phase frequency width (-90°)	Hz	60 to 100
Work temperature		℃	-40 to +100
Net weight		Kg	0.9