High Thrust, Integrated Roller-Screw Actuator Using High Performance Notched-Ribbon Motor Technology

The Navy is seeking a high thrust, linear electric actuator capable of replacing the hydraulic actuators currently used for the weapons elevator flight deck hatch (FDH) control. In the Phase I effort, a design concept was investigated which coupled a novel high torque, PM motor using notched-ribbon windings inline with a commercial high thrust roller screw. The results of this investigation found that this design, although roughly of acceptable diameter and weight, was too long to enable a direct, drop-in replacement of the current FDH hydraulic actuators. Furthermore, the packaging requirements of the roller screw mechanism and main bearing (and not the motor) were found to be the main cause. Therefore, a two stage effort is proposed for the Phase II project. The first will refine the current mechanical design to meet the FDH length requirement. Three approaches have been identified that either singly, or in combination, should result in a design that meets the length requirement. These approaches are to (1) optimize the key mechanical components (i.e. main bearing, end caps, and attachments), (2) replace the roller-screw with an NFC coated lead screw, or (3) package a high thrust, mechanical spring in parallel with the actuator. In the second stage of the Phase II project, a prototype system will be designed, constructed and tested to validate performance and manufacturability.