Model 252 Servovalves - bjfts.com

1 Model 252 Servovalves MTS Model 252 Servovalves are two Typical Applications Operation stage, four-way valves designed for servocontrol of hydraulic systems. Position, load, or velocity control of The Series 252 Servovalves utilize a These high performance Servovalves a hydraulic actuator in highly two stage design for precise control of are available in a range of flow rates dynamic applications. the flow of hydraulic oil. The first from 4 to 227 lpm (1 to 60 gpm). Pressure control in a dynamic pres- stage consists of a torque motor which surization system. deflects the armature and flapper assembly when an electrical signal is Standard Features & Benefits applied. The deflection of the flapper causes the flow through one of the Rugged design for long operating nozzles to increase and the other to life in dynamic applications. decrease. This creates a differential High resolution and low hysteresis pressure at the ends of the spool in for precise flow control.

2 The second stage causing it to move. 31 MPa (4500 Psi) operating pres- sure for and models. The spool moves until the feedback 21 MPa (3000 Psi) for mod- torque equals the armature torque, Model Serovalve els. and the flapper is re-centered. When Internal filtration to protect nozzle the flapper is re-centered the pressure orifices from contamination. on the two sides of the spool is equal High spool driving forces reduce the and the spools stays where it is. likelihood of a sticking spool due to dirty oil. Performance Notes Standard mounting configuration for and models allows The flow versus frequency perform- interchangeability between valves of ance curves indicate the relative per- different flow ratings. formance capabilities of the various 252 models at different frequencies. 252 Servovalve Options The valves were tested by driving Model Serovalve them with a sine wave at +/-100% of External Pilot Pressure The 252 the rated current.

3 The actual perform- Series Servovalves are available with a ance of a servo-controlled system is fifth port for external pilot pressure. influenced by many other variables External pilot pressure allows the sec- and the maximum operating frequency ond stage spool position circuit to be will depend on the other components pressurized and controlled without of the system as well as the test speci- applying system pressure to the actua- men itself. tor. This option is recommended when precise control of the servo-actuator The 252 Servovalves can be connected must be maintained when system in parallel to double the flow rate pressure is first turned on. when higher flows are required. A. dual valve configuration can offer advantages such as increased response First Stage Coil Magnets Upper Pole Piece Armature Flexure Tube Lower Pole Nozzle Flapper Second Stage Feedback Wire Spool Filter Fixed Orifice Model 252 Servovalves 252 Servovalve Specifications Model Force Rating* 90 Point @ 10% Max.

4 Operating Press. LPM GPM Command (Hz) Mpa PSI. 4 1 240 31 4500. 4 1 300 31 4500. 240 31 4500. 280 31 4500. 19 5 240 31 4500. 19 5 280 31 4500. 37 10 200 31 4500. 56 15 170 31 4500. 93 25 80 21 3000. 151 40 60 21 3000. 227 60 50 21 3000. * Flow rating are with 7 Mpa (1000 psi) pressure drop across the valve. Specifications subject to change without notice. Please contact MTS for specifications critical to your application. 252 Flow vs Frequency Performance 100 378 100 378 100 378. Flow in Gallons Per Minute Flow in Liters Per Minute Flow in Gallons Per Minute Flow in Liters Per Minute Flow in Liters Per Minute 10. Flow in Gallons Per Minute 10 37 10 37 37. 1 1 1 1 10 100 1000 1 10 100 1000 1 10 100 1000. Frequency in Hz Frequency in Hz Frequency in Hz Performance shown is with 21 MPa (3000 Psi) operating pressure and 7 MPa (1000 Psi) pressure drop across the valve. 252 Servovalve Order Information You can order a 252 Servovalve by 252 ServovalveCatalog Number selecting the Model that meets your (Pick one from each category - example: for the 37 lpm Model with inter- nal pilot pressure).

5 Performance requirements and des- ignating either the 4 port internal Serovalve or 5 port external pilot pressure 4 lpm (1 gpm). lpm ( gpm). connection. 19 lpm (5 gpm). 37 lpm (10 gpm). See MTS Model 252 Product Specification 56 lpm (15 gpm). number 300016-03 for more information. 93 lpm (25 gpm). 151 lpm (40 gpm). 227 lpm (60 gpm). 4 lpm (1 gpm). lpm ( gpm). 19 lpm (5 gpm). Ports -01 4 Port (Internal pilot pressure). -04 5 Port (External pilot pressure).