R-Series Rotary Electronic Actuators
High torque rotary actuators for precision positioning of control valves operating in high-temperature, high-vibration locations
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
|