Woodward

R-Series Rotary Electronic Actuators

    High torque rotary actuators for precision positioning of control valves operating in high-temperature, high-vibration locations

    R-Series Actuators 

    Woodward's new R-Series actuators are electronic modules integrated with a brushless DC motor and gear box. A simple change of the gear box enables different torque outputs. Both the R-11 and R-30 models accept either a 4 to 20 mA, 0 to 200 mA, or PWM (pulse width modulated) command signal while providing a 4 to 20 mA output shaft position signal that external devices can use as direct feedback of the output shaft's position. The 73° of travel enables the actuator to be connected directly to butterfly-type throttles, eliminating the need for failure-prone intermediate linkage. This larger rotary travel also provides more useful work output than actuators with the same torque output but with less rotary travel.

    The R-Series actuators are ideal for use on control valves in reciprocating engine applications that include fuel throttles, wastegates, exhaust gas recirculation (EGR), compressor recirculation (bypass), waste heat recovery (WHR), and exhaust. Additional applications on reciprocating engines include variable turbine geometry (VTG) turbocharger actuation.

    Woodward has coupled R-Series actuators with its newly-designed Glo-Tech hot valves to precisely control the flow of high temperature gases up to 780°C. The R-Series actuators in the Glo-Tech System are sized to match the valve, minimizing the electrical power required while providing fast, precise valve positioning. TheGlo-Tech System of valves and actuators helps engines from 750 kW and above meet their performance and emissions goals.

    Advantages Over Other Rotary Actuators

    • Accurate, non-contacting, position sensing
    • Lower cost than similar electric actuators delivering the same torque
    • Higher torque output in a smaller package
    • Multiple output torques available using the same motor and electronics
    • Low supply current
    • High accuracy: ±-1.36% of full travel
    • Robust control over a wide range of friction
    • Higher temperature rating (up to +105°C)
    • Rotary output with 73° of travel for greater work output
    • Lower weight than LAT actuators
    • Meets IP67 ratings; withstands rain and power washing
    • Designed to pass marine certifications
    • Custom cabling options

     

     

     

    Work Output 

    Model

    Work Output Continuous*

    Torque Output Transient

    Torque Output Continuous

    R-11

    7.2 J

    5.3 ft-lb

    11 N·m

    8.1 lb-ft

    5.5 N·m

    4 lb-ft

    R-30

    19.6 J

    14.5 ft-lb

    30 N·m

    22.1 lb-ft

    15 N·m

    11 lb-ft

    *  Continuous Work Output is measured over 73° of rotation. Good control of fuel racks requires the actuator to deliver a defined force over a defined distance, also known as work. Since work is the ultimate requirement, rotary actuators are best sized and compared based on continuous work rating: Continuous work (joules) = 0.01745 x continuous torque (N·m) x rotation angle (degrees)

     

    Inputs and Outputs 

    Power Input

    18-32 Vdc with out-of-range diagnostics

    Command Input

    PWM: 8-32 Vdc, 100 to 2000 Hz (accepts push-pull and high-side or low-side open collector)

    Analog: 0-200 mA, 4-20 mA

    Output Shaft Rotation

    73 degrees ±2 degrees

    Position Feedback Output

    4-20 mA corresponding to 0 %
    to 100 % travel

    Discrete Input

    Key-switch low power standby mode. Applying input power to the key-switch input activates the actuator, making it ready to position in less than 300 ms. Removing the key-switch input power safely shuts down the actuator and its power draw is less than 2 mA

    Discrete Output

    Normally "ON" and turns "OFF" to indicate shutdown is active

     

    Performance 

    Accuracy

    ±1.36 % over the full rotational travel, from -30 to +105 °C, + input signal error. At < -30 °C, the position error can grow to ~ ±5%

    Max Slew Time

    (10 % to 90 % travel)

    R-11 = 75 ms

    R-30 = 105 ms

    Small Signal Bandwidth

    6 Hz (minimum)

    Repeatability

    ≤1.0 % of full stroke at 25 °C

    Gearbox Backlash

    < 0.5 degrees

    Side Load on Output Shaft

    396 N / 89 lb (maximum)

    Thrust Load on Output Shaft

    67 N / 15 lb (maximum)

    Maximum Load Inertia

    R-11 < 2.19E-3 kg-m² (1.94E-2 in-lb-s²)

    R-30 < 5.26E-3 kg-m² (4.66E-2 in-lb-s²)

     

    Environmental 

    Operating Temperature Limits

    -40 °C to +105 °C (from -30 °C to -40 °C, position error can grow to ±5% of full travel)

    Under all conditions, the Temperature Monitoring Zone must remain
    below 105 °C

    Storage Temperature

    -40 °C to +125 °C, unpowered

    Mechanical Shock

    US MIL-STD-810F, Method 516.5, Procedure 1, 40 G peak, 11 ms duration, saw-tooth pulse

    Ingress Protection

    IP67 per IEC 60529, NEMA Type 4 enclosure

    Humidity

    95 % Relative Humidity:12 hours at
    60 °C and 7 hours at 25 °C with 5 hours of transition for 5 complete cycles

    Chemical Resistance

    The actuator uses materials proven capable of withstanding normal engine environment chemicals per SAE J1455, such as diesel fuel, engine oil, and antifreeze