There is provided a dual rack and pinion rotational inerter system for damping movement of a flight control surface of an aircraft. The system has a flexible holding structure disposed between the flight control surface and a support structure of the aircraft. The system has a dual rack and pinion assembly held by and between the flexible holding structure. The dual rack and pinion assembly has a first rack, a second rack, and a pinion engaged to and between the racks. The system has a first terminal coupled to the first rack and coupled to the flight control surface, via a pivot element, and a second terminal coupled to the second rack, and coupled to the support structure. The system has a pair of inertia wheels adjacent the flexible holding structure. The system has an axle element inserted through the inertial wheels, the flexible holding structure, and the pinion.

An electric actuator comprises a housing and an output shaft reciprocatingly received by the housing. There is a screw assembly disposed within the housing and coupled to the output shaft. The screw assembly includes a plurality of annular rollers and a central screw received by the annular rollers. The annular rollers are rotatable about the central screw. There is a motor which includes a stator and a rotor. The rotor has an inner bore which engages the annular rollers. Rotation of the rotor causes the central screw to translate axially relative to the rotor and the output shaft to reciprocate relative to the housing.

Provided are a low-cost ball screw device having a low-cost deflector, wherein the deflector is formable by simple machining, is easy to handle after being machined, and thus is easy to store and mount to another component. A ball screw device includes a screw shaft, a nut, rolling elements, and deflectors. Mounting holes each have a pair of circumferentially facing surfaces that face toward each other in the circumferential direction of the nut and parallel to each other. When a plane passing through the center point of an opening in one end of a second circulation path in each of the pair of deflectors and the axis of the nut is defined as a reference plane, an intersection line between an imaginary perpendicular plane perpendicular to the axis and the pair of circumferentially facing surfaces has an angle with respect to the reference plane.

An electromechanical actuator (EMA) is provided. The EMA may comprise a ball nut having an annular geometry centered about an axis. A dual ball screw may be disposed radially inward from the ball nut and configured to rotate about the axis. The dual ball screw may also be mechanically coupled to the ball nut. A ball screw may be disposed radially inward from the ball nut and configured to rotate about the axis. The ball screw may also be mechanically coupled to the dual ball screw.

A linear motor includes a rotor rotatable relative to a surrounding rotor sleeve and about a central axis. At least one opening extends between an inner surface and an outer surface of the rotor. An externally threaded leadscrew extends through the rotor and along the central axis. An internally threaded nut is located within and mated to the rotor so as to rotate with the rotor about the central axis and ride along the leadscrew. A first cavity is located between the nut and a first bushing set against the inner surface of the rotor and a second cavity is located between nut and a second bushing set against the inner surface of the rotor. The at least one opening in the rotor forms a passage between the first and second cavities and is defined between the sleeve and nut so as to communicate excess lubricant.

A linear electric actuator for steering systems includes: a casing, an electric motor, housed in the casing, which is provided with a stator and a hollow rotor internally concentric to the stator, a holder nut internally fixed to the rotor, and a stem having a thread coupled to the holder nut. The stem includes a first portion provided with a surface treatment, which projects outside the casing, and a second portion without said surface treatment, which is contained inside the casing and in which the thread is obtained.

An electromechanical linear actuator having a threaded drive, which comprises a threaded nut connected to a cantilever tube and a lead screw connected to a hollow shaft of an electric motor via a rotationally fixed connection in such a way that, by a rotation of the hollow shaft and the lead screw, the threaded nut and the cantilever tube are linearly movable. An axial design length of the electromechanical linear actuator in the maximally retracted state is minimized in that a holding brake for the lead screw and a first rotary bearing for bearing the lead screw on a housing of the linear actuator are arranged within the hollow shaft.

A planetary roller screw linear actuator includes a shell with a receiving cavity, a driving assembly fixed in the receiving cavity, and a rotor received in the receiving cavity and driven by the driving assembly to rotate. The rotor includes a hollow shaft rotatably connected to two ends of the shell, a planetary screw rotating body in transmission connection to the shaft, and an extension rod in transmission connection to the planetary screw. The shaft is made of a magnetic material. A detection position magnet is fixed to an end of the shaft and an induction assembly is fixed to the shell and spaced from the magnet. An axial projection of the magnet is located in the shaft. A magnetic field of the magnet is not affected by an external magnetic field, and a position of the rotor is accurately determined.

A step actuator includes a housing, a stator in the housing, a rotor including a magnet provided radially inward of the stator and a nut member inserted into the magnet and protruding through one side of the housing, a bearing rotatably supporting the nut member, a screw member coupled with the nut member to linearly move as the rotor rotates, and a mounting member supported on one side of the housing to support the screw member in such a manner that the screw member is linearly movable. The nut member includes an end portion passing through the bearing and a coupling portion extending from the end portion to couple with the bearing.

An electromechanical actuator is provided whose structure is simplified and made small, and with which an output portion can be driven even if a jammed state occurs in a screw mechanism. An electromechanical actuator is configured that includes an electric motor having a first rotor portion and a second rotor portion capable of relative rotation with respect to each other, and a jam relief mechanism having a first conversion portion having a first screw mechanism capable of converting rotational force of the first rotor portion into thrust force and moving an output portion back and forth, a sliding support mechanism which can transmit the rotational force of the first rotor portion to the first conversion portion, and a second conversion portion having a second screw mechanism which moves the output portion back and forth together with the first conversion portion.