Dual Redundant L-Series linear actuation product

The Dual Redundant L-Series is a linear servo actuator from Ultra Motion, an electromechanical actuator with redundant motors, control electronics and position sensing for aerospace, defense, industrial and maritime systems. It converts electrical commands into linear force through a ballscrew and is used where a single electrical fault must not stop the actuation.

The L-Series actuators are driven by a high power density brushless DC motor combined with a planetary gearhead. Power passes through a spur gear train to a precision-ground, preloaded ballscrew, and a duplexed angular contact bearing takes all thrust loads with zero axial backlash. The preloaded load path increases control authority, stiffness and reliability. Position is measured by Ultra Motion's contactless absolute position feedback (Phase Index), and the control electronics are built into the actuator.

The dual redundant version is made of redundant motors, redundant control electronics and a triplicated absolute position sensor for voting. Ultra Motion states that all control over the redundant operation is left to the user: the actuator makes no arbitration, voting or redundancy decisions. There is no internal communication between the redundant controllers or the triplicated sensor, and they are 100 percent electrically isolated, so the host can run the actuator in cold standby or with load sharing.

The L-Series data are as follows. Peak force is up to 1250 lbf and peak speed up to 5 in/s, with standard strokes of 1.75 in, 3.125 in and 7.5 in. The mass is 3.05 lbm for the 3.125 in stroke, and nominal backlash is zero because the load path is preloaded. The supply range is 10 to 36 VDC with an absolute maximum of 62 VDC, and the operating temperature range is -40 degrees C to +100 degrees C. These figures tell the integrator which loads, travel and bus voltages the actuator suits.

Integration uses CAN 2.0B or RS-485 serial communication, which allow full control of position and phase currents and return telemetry on the health and state of the actuator. An optically isolated enable input acts as a hardware disable that removes power from the motor bridge, bypassing the onboard electronics. The electrical interface is a Series-5 D38999 connector (S500DZ-10-35PN) with pins for ground, enable, RS-485, CAN and supply. Sealing is IP67, with O-ring sealed joints and a spring-energised PTFE shaft seal, and the faying surfaces are chem-filmed for continuous enclosure conductivity and EMI/EMC protection. STEP files and a manual are available from the maker, and vacuum modifications and customisations are offered.

Typical applications named by the maker are swashplate and tail-rotor control and fixed-wing control surfaces on uncrewed aerial vehicles, utility actuation, and rudder control or accessory deployment on uncrewed surface vehicles.