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 actuating cylinder has a housing, an actuation rod mounted to be longitudinally movable in the housing and a push tube connected to the actuation rod. An electric motor is provided with a stator and with a rotating rotor shaft. A screw mechanism includes a screw connected to the actuation rod. The rotor shaft is disposed around the screw. A plurality of rolling elements are disposed between the screw and the rotor shaft. A rotational movement of the rotor shaft is converted into a linear movement in translation of the screw and of the actuation rod. A lubrication channel extends through the push tube, the actuation rod and the screw. The lubrication channel has an inlet portion that is open to an external surface of the push tube and provided with a temporary plug or nipple, and an outlet portion that is open to the external thread of screw.

An actuating cylinder has a housing with a main body and a front cover. An actuation rod is mounted for longitudinal movement relative to the housing. An electric motor has a stator and a rotating rotor shaft that is disposed around a screw of a screw mechanism that is connected to the actuation rod. A plurality of rolling elements convert a rotational movement of the rotor shaft into a linear, translation movement of the screw and of the actuation rod. A bearing supports the rotation of the rotor shaft with respect to the housing. A load path ring has an outer ring portion in axial abutment against a fixed part of the bearing, and an inner ring portion connected internally to the outer ring portion. A load sensor is axially clamped between the front cover and the inner ring portion of the load path ring.

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.

Actuators, systems, and methods for controlling tools are disclosed. One actuator includes a first motor, a second motor, and a controller. The first motor is operable to rotate a first threading extending in a first helical direction around an axis. The second motor is operable to rotate a second threading axially spaced apart from the first threading and extending in a second helical direction opposite the first helical direction around the axis. The controller is in communication with the first and second motors. The controller is configured to control speed and direction of the first and second motors to effect a desired pattern of axial and rotational movement of the tool. One method includes rotating the first threading in a first rotational direction, and simultaneously, rotating the second threading in a second rotational direction opposite the first direction.

Actuator for actuating a valve device comprising an electric drive (14) being operatively engaged to an actuating element (1) of the valve device, the electric drive (14) comprising at least one torque motor (2) which drives a hollow shaft (3) as an internal rotor, that positions a threaded drive (4) having a screw nut (6) and a threaded spindle (5) for converting the rotational movement of the hollow shaft (3) into a translational movement of the threaded spindle (5), and the threaded spindle (5) acts upon the actuating element (1) for displacing the same, wherein the threaded drive (4) comprises an inverted roller screw (4.1), and the screw nut (6) of the inverted roller screw (4.1) houses the threaded spindle (5) as a push rod.

A linear actuator drive arrangement is disclosed. The arrangement includes a linear actuator assembly including a motor, a drive screw arranged within the motor that is axially driven by the motor, and a linear actuator housing surrounding the motor. An outer housing surrounds the linear actuator housing. The outer housing is fixed to the drive screw and axially slides relative to the linear actuator housing when the drive screw is axially driven by the motor. An anti-rotation retainer is arranged between the linear actuator housing and the outer housing that (1) provides an axial end stop for an extended position of the outer housing located between the outer housing and the linear actuator housing, and (2) prevents relative rotation between the linear actuator housing and the outer housing.

There is provided a dual rack and pinion rotational inerter system for damping movement of a flight control surface of an aircraft having a support structure. The system has a flexible holding structure disposed between the flight control surface and the support structure. The system has a dual rack and pinion assembly held by the flexible holding structure. The system has a first terminal and a second terminal, coupled to the dual rack and pinion assembly. The first terminal is coupled to the flight control surface. The system has a pair of inertia wheels coupled to the flexible holding structure. The system has an axle element inserted through the inertia wheels, the flexible holding structure, and the dual rack and pinion assembly, such that when the flight control surface rotates, the dual rack and pinion rotational inerter system translates and rotates, and movement of the flight control surface is dampened.

The invention relates to a drive device, particularly comprising an internal rotor motor, with a motor housing, a stator for a winding and a rotor having at least one permanent magnet, wherein the motor housing has a housing part extending substantially radially on one side of the stator and the rotor has two rotor bearings. The rotor bearings are arranged on the substantially radially extending housing part or on a part connected thereto which extends substantially axially.

A rotary unit of this motor has a plurality of magnets, a hollow shaft which has a tubular shape, and a ball nut. Each of the magnets is in contact with an outer surface of the hollow shaft. The ball nut is disposed on a radially inner side of the hollow shaft. At least a portion of the magnets, at least a portion of the hollow shaft, and at least a portion of the ball nut overlap in a circumferential direction. The hollow shaft and the ball nut are made of a magnetic material. An inner circumferential surface of the hollow shaft and an outer circumferential surface of the ball nut are in contact with each other.