A compact, efficient, and reliable electromechanical actuator that is capable of driving heavy loads at a high rate of speed and also capable of resisting large back driving forces. The actuator resists tension and compression back driving forces in a static state as well as when the actuator extends and retracts. The back driving forces are resisted even if the electronics (e.g., motor) fail.

A linear actuator (1) and the centrifugal safety device (50) thereof is disclosed. The safety device (50) includes an outer socket (51) having a stop portion (512) and a first accommodation portion (513), an inner socket (53) having a raised portion (531) and a second accommodation portion (532) and a centrifugal assembly (55) having a centrifugal block (551) and an elastic element (555). The inner socket (53) drives the centrifugal assembly (55) to rotate. If the centrifugal force of the centrifugal block (551) is smaller than the elasticity of the elastic element (555), then the centrifugal block (551) is limited in the second accommodation portion (532) by the elastic element (555), or else the centrifugal block (551) moves into the first accommodation portion (513) and clamped by the raised portion (531) and the stop portion (512).

An apparatus for a thrust reverser actuation system (“TRAS”), the apparatus comprising: an input shaft; a first component located concentrically around the input shaft; a second component located concentrically around the first component; a first ballscrew mechanism between the input shaft and the first component, and configured such that rotational movement of the input shaft causes a translational movement of the first component via the first ballscrew mechanism; and a second ballscrew mechanism between the first component and the second component, and configured such that rotational movement of the first component causes a translational movement of the second component via the second ballscrew mechanism.

A linear actuator comprising a housing with first and second ends, and defining a central cavity extending axially therethrough; a tube having first and second portions, the first portion arranged to slide within the central cavity of the housing, and the second portion extending outwardly from the second end of the housing; a first elongated rotatable screw positioned axially within the central cavity and coaxial with the tube; a first nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second nut and the second end of the housing.

A linear stage assembly comprising a nut having a wall defining a bore which has a nut helical thread which includes: a crest, a root, and a flank between the crest and root; a screw having a screw helical thread about an exterior which includes: a crest, a root, and a flank between the crest and the root; wherein the nut and the screw are in a mating relationship so that the nut flank and the screw flank are in contact with one another defining a contact interface which imposes a frictional force that is sufficiently small to allow generally longitudinal movement in response to an actuation load of the screw or the nut relative to the other and sufficiently large to prevent back drive of the screw or the nut relative to the other after the actuation load is removed and in response to an opposing reaction force.

A system comprises a drive system comprising a single motor, a transmission configured to transmit power from the single motor to a first ball screw via a first clutch, and a second clutch configured to transmit power from the first ball screw to a second ball screw. The system also comprises a brake configured to apply a braking force to at least a portion of the drive system. The system further comprises a control module configured to control operation of one or more of the single motor, the first clutch, the second clutch, and the brake, where the control module is configured to move a scissors arms in a horizontal direction in a first configuration and adjust a vertical height of the scissors arms in a second configuration.

Some embodiments relate to an electro-mechanical actuator that includes a screw, structurally segregated (split) housings, first and second nuts coupled to the screw, a sensor assembly, a plurality of motors, and a controller. The first nut is coupled to a first mounting point, and the second nut is coupled to a second mounting point. The sensor assembly may generate signals indicative of (e.g., relative) positions of left and right units of the actuator or positions of the first nut and the second nut on the screw. The controller controls the motors based on the signals generated by the sensor assembly. The motors may rotate each nut about a screw axis of the screw. This rotation results in one or both nuts moving along the screw. Movement between the first nut and the second nut along the screw adjusts a distance between the first mounting point and the second mounting point.

An electric actuator has a housing, an electric motor mounted on the housing, a speed reduction mechanism, and a ball screw mechanism that converts the rotational motion of the electric motor to axial linear motion of a drive shaft. An annular groove is formed on an open end of the blind bore of the housing. The sleeve is axially immovably secured by a annular stopper ring fit into the annular groove. The stopper ring has one notch and a recess formed on its inner circumference near each of its two ends of the stopper ring. A contour of each recess has a circular arc portion and a flat portion. The circular arc portion has a predetermined radius of curvature. The flat portion tangentially extends from the circular arc portion. A width of the opening of the recess is smaller than a diameter of the circular arc portion.

The invention relates to a refinement of a spindle drive (1), and to a louvered window or a louvered shutter having a spindle drive for moving louver elements such that applied return forces and return torques can be absorbed better, and in particular without placing a load on the drive motor. For this purpose, the spindle drive (1) has a specially designed return stop mechanism (6) arranged between a drive shaft of a drive motor (3) and a threaded spindle (4).

Linear actuator, where a reversible electric motor (20) through a transmission (21) drives a non-self-locking spindle (22), by means of which an adjustment element (24) secured against rotation can be moved axially for adjusting an element connected thereto such as a backrest section in a bed. The actuator further comprises a quick release (27) for disengagement of the adjustment element (24) from the electric motor (20) and the part of the transmission (21) extending from the electric motor (20) to the quick release (27), such that the spindle (22) is rotated under the load on the adjustment element (24). Further, the actuator comprises brake means for controlling the speed of the adjustment element (24), when the quick release (27) is activated. The brake means are constituted by a rotary damper (45) of the fluid type comprising an internal body located in a liquid-filled hollow in an outer body, where one body is in driving connection with the spindle (22) or the part of the transmission extending from the spindle (22) to the quick release (27), and where a dampening effect, which dampens the speed of the spindle (22) and thus the adjustment element (24), is generated when this body is rotated relative to the other body as a result of activation of the quick release (27). It is thus possible to provide a construction where the lowering speed is self-controlling when the quick release is activated.