Model 915 rotary servo actuator

The Moog Rotary Servo Actuator is a rotary actuator for unmanned air vehicle flight control surfaces, built to operate under extreme environmental conditions. It positions the control surfaces of the QF-4 unmanned air vehicle, serving as the servo drive between the flight control command signal and the surface.

The actuator takes an analog command input in the form of a bipolar voltage signal and drives its output shaft to the commanded angle. A film position transducer provides position feedback, and a position output signal is available for monitoring. Electronic position and torque limiting bounds both the travel and the torque the actuator can apply, while an output shaft disconnect clutch allows the output shaft to be released from the drive.

The key figures define the load and response envelope. Peak torque is 33.8954 Nm, the maximum load torque the actuator is specified to deliver at the output shaft. The no-load speed is 250 °/s; because it is a no-load figure, surface rates under aerodynamic load should be confirmed with the maker for a given installation. The rotation range is ±46°, which sets the available surface deflection around the neutral position. Mass is 3,175.15 g, a figure an airframe designer must budget at the control surface station.

For integration, the actuator runs from a 28 V DC supply and is commanded by an analog signal, so it interfaces with analog flight control electronics and servo loops without a digital bus. The position output signal and the film position transducer support closed-loop control and monitoring. High-efficiency steel gearing and low backlash keep positioning accurate and make the output shaft respond predictably to small commands. The robust structural design supports operation under the extreme environmental conditions the actuator is built for. The housing dimensions are listed in the specifications and set the envelope an installer must reserve in the airframe.

No certifications or qualification standards are listed for this actuator. Qualification status for a given program should be confirmed with Moog applications engineers, who can also tailor the rotary actuator to a specific application.

Typical applications are control surface actuation on the QF-4 unmanned air vehicle and comparable control surface positioning tasks on defense and aerospace uncrewed platforms that call for an analog-commanded rotary servo actuator with position and torque limiting and an output shaft disconnect clutch.