PA-RR-260-8 rotary actuation product

The PA-RR-260-8 is a redundant rotary servo actuator from Pegasus Actuators, built for safety-critical unmanned systems. It is a stand-alone electromechanical actuator with two independent channels that moves a control surface, swashplate or other mechanism through its output shaft and keeps working after a single failure.

The redundancy is handled inside the actuator. All decisions related to redundancy are made internally, so the autopilot does not need modified software or its own voting logic; the only requirement is two identical command channels for each actuator. If a component fails, the actuator sends a specific warning signal to the autopilot, and the maker states that it continues to deliver its full torque, rotational speed and bandwidth after a single-point failure. For an integrator this means a servo that can replace a standard unit in flight-critical positions on unmanned aircraft such as fixed-wing, helicopter and VTOL platforms.

The key figures are as follows. Continuous torque is 300 Ncm and maximum torque is above 500 Ncm. The no-load speed is 210 degrees/sec at 24 VDC, which is the rate at which a control surface can be driven when the load is light. The travel angle is 315 degrees, measured by a redundant contactless angle sensor. The actuator weighs 480 g, a figure for the mass budget of a small unmanned aircraft.

Inside, the actuator has a dual servo controller with digital position feedback, a dual brushless DC motor with neodymium magnets, and a gear train of hardened steel spur gears with 8 ball races and an overload protection on the output shaft. The case is aluminium and is protected against water and dust to IP67, with a solid horizontal and vertical four-point fixation for mounting.

For integration, the operating voltage is 24 VDC. The standard signal interface is an RS-485 data protocol, with CANopen CiA 402 available as an option. Electrical connection uses a Glenair Series 801 size 6-7 connector, and the maker lists an extension cable with a mating connector, mating connectors with pins in olive or black finish, a programming adapter cable, and the PA-Control 3 programming tool for setting parameters. Mechanical accessories include the installation frame PA-IF-260-8-01 and aluminium universal levers with a 6.5 mm square bore that also fit R-250 and RR-260 actuators. Datasheet and drawing files are available from the maker.

Typical applications are primary flight control on unmanned aircraft where a single servo failure must not cause loss of the aircraft, as well as swashplate and rudder actuation on larger unmanned helicopters and VTOL vehicles, and other unmanned systems that need fault-tolerant positioning.