Abstract: Contemplated couplings include an intermediate shaft internal and coaxial to a driver and a driven shaft, wherein the intermediate shaft moves a plurality of teethed rollers that engage with corresponding splined inner surfaces of the driver and the driven shaft. Such devices allow separation of the shafts under load using substantially reduced force and will typically have a friction coefficient virtual ? of less than 0.05.

Abstract: Electrically controlled and/or actuated landing gear mechanisms are presented that allow for adjustment of aircraft attitude on the ground as well as for retraction and extension of the landing gear in a single unit. Most preferably, the electric actuator is positioned within the diameter of the strut to thereby form a compact and load bearing structure.

Abstract: Direct drive electromechanical rotary-to-linear actuators include one or more electric motors mounted in a housing. Each motor includes a stator and a rotor. The motor drives a planetary drive mechanism that includes an elongated central shaft having one or more helical threads on an external surface coupled to the rotor for conjoint rotation. A planetary nut having helical threads on an internal surface is disposed concentric to the shaft, and a plurality of planetary rollers are disposed concentrically between the shaft and the planetary nut. Each of the rollers has a helical thread on an external surface that is complementary to and in engagement with a thread of the shaft and a thread of the nut. Rotation of the rotor is converted with mechanical advantage into linear movement of the planetary nut. The actuators provide backlash-free operation, higher stiffnesses, slew rates and frequency responses, and better overall efficiency.