Directional servo-valves, with mechanical position feedback 4WS2EM 10…XD

Description

• Size 10
• Component series 5X
• Maximum operating pressure 315 bar
• Maximum flow 180 l/min
• Area of application in accordance with the Explosion Protection Directive 2014/34/EU: II 2G
• Types of protection of the valve:
  Ex db IIB T4 Gb according to EN IEC 60079-0 / EN 60079-1 and IEC 60079-0 / IEC 60079-1

Features

• 4 or 3-way version
• For intended use in potentially explosive atmosphere
• Valve to control position, force, pressure or velocity
• For subplate mounting
• Porting pattern according to ISO 4401-05-05-0-05
• Dry control motor, no contamination of the solenoid gaps by the hydraulic fluid
• Wear-free control spool return element
• Pressure chambers at the control sleeve with gap seal, therefore no wear of the seal ring

Product description

Valves of type 4WS2EM are electrically operated, 2-stage directional servo valves. They are mainly used to control position, force, pressure or velocity.

The valves consist of an electro-mechanical converter (torque motor) (1), a hydraulic amplifier (nozzle flapper plate system) (2) and a control spool (3) in a sleeve (2nd stage), which is connected to the torque motor via a mechanical feedback.

An electrical input signal at the coils (4) of the torque motor generates a force by means of a permanent magnet which acts on the armature (5), and in connection with a torque tube (6) results in a torque. This causes the flapper plate (7) which is connected to the torque tube (6) via a bolt to move from the central position between the two control nozzles (8), and a pressure differential is created across the front sides of the control spool (3). The pressure differential results in the control spool changing its position, which results in the pressure port being connected to one actuator port and, at the same time, the other actuator port being connected to the return flow port.

The control spool (3) is connected to the flapper plate or the torque motor by means of a bending spring (mechanical feedback) (9). The position of the control spool (3) is changed until the feedback torque across the bending spring and the electro-magnetic torque of the torque motor are balanced and the pressure differential at the nozzle flapper plate system becomes zero.

The stroke of the control spool (3) and consequently the flow of the servo valve are controlled proportionally to the electrical input signal. It must be noted that the flow depends on the valve pressure drop.

External control electronics (separate order)

External control electronics (servo amplifier) serve the actuation of the valve, amplifying an analog input signal (command value) so that with the output signal, the servo valve is actuated in a flow-controlled form.

For the limitation of the electric data, a safety barrier is to be connected between valve and amplifier (see "Electrical connection").

Type 4WS2EM 10...XD...

Type code

Technical data

(For applications outside these values, please consult us!)

general

hydraulic

static / dynamic

electrical

Notice:

In case of control using non-Rexroth amplifiers, we recommend a superimposed dither signal.

Information on explosion protection

Special application conditions for a safe application

For ensuring the type of protection d "flameproof enclosure", the occurrence of explosive atmospheres in the hydraulic area of the valve must be securely avoided. This may be ensured by applying a sufficiently high pilot pressure (≥10 bar in channel P and/or X) before applying an electrical signal at the coils or the electronics.

Diagrams/characteristic curves

(measured with HLP32, ϑOil = 40 ±5 °C)

Tolerance field of the flow/signal function with constant valve pressure differential Δp

Standard

Tolerance field of the flow/signal function with constant valve pressure differential Δp

Special version "-100"

Tolerance field of the flow/signal function with constant valve pressure differential Δp

Special version "-102"

Flow/load function

(Tolerance ±10 %) with 100 % command value signal

Notices:

• Flow values in the maximum command value range (see tolerance field of the flow/signal function)

• ∆p = pP – pL – pT

• ∆p valve pressure differential
  pP inlet pressur
  pL load pressure
  pT return flow pressure

Zero flow

(with spool overlap "E", measured without dither signal)

Transition function with pressure rating 315 bar, step response without flow

Version "5", "10", "20"

Transition function with pressure rating 315 bar, step response without flow

Version "30"

Transition function with pressure rating 315 bar, step response without flow

Version "45"

Transition function with pressure rating 315 bar, step response without flow

Version "60"

Transition function with pressure rating 315 bar, step response without flow

Version "75"

Transition function with pressure rating 315 bar, step response without flow

Version "90"

Frequency response with pressure rating 315 bar, stroke frequency without flow

Version "5", "10", "20"

Frequency response with pressure rating 315 bar, stroke frequency without flow

Version "30"

Frequency response with pressure rating 315 bar, stroke frequency without flow

Version "45"

Frequency response with pressure rating 315 bar, stroke frequency without flow

Version "60"

Frequency response with pressure rating 315 bar, stroke frequency without flow

Version "75"

Frequency response with pressure rating 315 bar, stroke frequency without flow

Version "90"

Dependency of the frequency f at -90° of the operating pressure and the inlet amplitude

Version "5", "10", "20"

Dependency of the frequency f at -90° of the operating pressure and the inlet amplitude

Version "30"

Dependency of the frequency f at -90° of the operating pressure and the inlet amplitude

Version "45"

Dependency of the frequency f at -90° of the operating pressure and the inlet amplitude

Version "60"

Dependency of the frequency f at -90° of the operating pressure and the inlet amplitude

Version "75"

Dependency of the frequency f at -90° of the operating pressure and the inlet amplitude

Version "90"

Symbols/Circuit diagrams

	Control spool overlap
	"E"	"C"; "D"
Standard
Special version "-100"
Special version "-102"

Notice:

Representation according to ISO 1219-1.

Electrical connection

Example: parallel connection

Connection line

The electrical connection can be designed as parallel or serial connection. For reasons of operational safety and the resulting lower coil inductivity, we recommend the parallel connection.

Parallel connection

Connect the "orange" cable connector with "black" and "brown" with "blue".

Serial connection

Connect the "brown" cable connector with "black".

The electrical control at "orange" (+) and "blue" (–) provides for the direction of flow P → A and B → T. Reverse electrical control provides for direction of flow P → B and A → T.

Notices:

• The free end of the connection cable must be connected as follows according to the construction provisions:
  • outside the potentially explosive area or
  • within the potentially explosive area in terminal boxes of an acknowledged type of protection

• Only use finely stranded conductors if they have pressed-on wire end ferrules.

Dimensions

Dimensions in mm

Required surface quality of the valve contact surface

Valve mounting screws (included in the scope of delivery)

Notice:

Only use valve mounting screws with the listed thread diameters and strength properties. Observe the screw-in depth.

Subplates (separate order) with porting pattern according to ISO 4401-05-05-0-05, see data sheet 45100.

Notices:

• Subplates are no components in the sense of directive 2014/34/EU and can be used after the manufacturer of the overall system has conducted an assessment of the risk of ignition. The "G...J3" versions are free from aluminum and/or magnesium and galvanized.

• The dimensions are nominal dimensions which are subject to tolerances.

Accessories

Flushing plate with porting pattern according to ISO 4401-05-05-0-05

Dimensions in mm

Ordering code and further information:

• Material number R901541299

• Weight 2 kg

• Identical seal rings for ports A, B, P, T and T1

• Identical seal rings for ports X and Y

• Mounting screws (included in the scope of delivery)
  • 4 hexagon socket head cap screws ISO 4762 - M6 x 50 - 10.9
  • (Friction coefficient μtotal = 0.09 … 0.14)
  • Tightening torque MA = 12.5 Nm ±10 %
  • For reasons of stability, exclusively the specified valve mounting screws may be used.

Notice:

Before assembly and operation, please observe the information in the operating instructions.

Valve amplifiers for servo-valves

VT 11021-1X

Valve amplifiers for servo-valves

VT 11021-1X

• Component series 1X
• Analog, Modular design
• For valves: 4WS2EM 6-2X, 4WS2EM 10-5X and 4WS2EM 16-2X

• Data sheet

• Configurator / CAD

• Spare parts and repair

Valve amplifiers for servo-valves

VT-SR2-1X

Valve amplifiers for servo-valves

VT-SR2-1X

• Component series 1X
• Analog, Euro-card format
• For valves: 4WS2EM 6-2X, 4WS2EM 10-5X and 4WS2EM 16-2X

• Data sheet

• Configurator / CAD

• Spare parts and repair

Downloads

	Directional servo valve with mechanical position feedback Data Sheet | RE29583-XD | 2020-11-01 | English, United States | PDF | 976k Product Groups: Directional servo-valves Type 4WS2EM …XD
	4-way servo valve with mechanical position feedback Manual | RE29583-XD-B | 2020-10-01 | English | PDF | 1.5MB Product Groups: Proportional, high-response and servo valves Type 4WS2EM10..5X/...XD...
	Explosion-protected hydraulic products for industrial and mobile applications Brochure | R999000373 | 2017-03-01 | English | PDF | 5.8MB Product Groups: Pumps, CD - single rod cylinder, Proportional, high-response and servo valves, Axial piston pumps, Mobile controls Product overview