A motion conversion mechanism includes a shaft having an external thread and a cylinder having an internal thread that is screwed with the external thread. The motion conversion mechanism converts rotating motion of one of the shaft and the cylinder into linear motion of the other of the shaft and the cylinder. The cylinder is provided with two internal thread portions, each having the internal thread, such that a threadless portion is interposed between the two internal thread portions in an axial direction.

According to an aspect of some embodiments of the present invention there is provided a piston mounted on and fixedly fastened to a ball screw nut, the nut threaded onto a ball screw. By mechanically rotating the piston and preventing the ball screw from rotating, the balls screw nut rotates, thereby raising or lowering the ball screw, thereby raising or lowering the piston, thereby raising or lowering a casing, for example a bollard, mounted on the piston. The casing may be raised or lowered by attaching a handle to the piston and rotating the handle.

Linear actuator comprising an electric motor (6), which through a transmission (12) drives a spindle unit comprising at least one spindle (10) with a spindle nut (13). A tubular adjustment element (3) in connection with the spindle unit is displaced either outwards or inwards depending on the direction of rotation of the spindle unit. A brake in the shape of a coil spring (21) is arranged in connection with a cylindrical element (15) for retaining the tubular adjustment element (3) in a given position when the power for the electric motor (6) is cut off. The cylindrical element (15) is designed as a separate cylindrical element arranged on the spindle (10) or a shaft in the transmission (12). The separate cylindrical element (15) is preferably arranged on a rear end of the spindle (10) between the rear mounting (4) and the bearing (11) for the spindle (10). Compared to the known constructions, where the spring is positioned on a cylindrical element on the side of a worm wheel, the heat generation is limited, just as the heat is led out to the rear mounting.

A linear actuator with an electric motor at one end and an electro-mechanical brake at the other, which is used to deploy and retract expandable rooms of recreational vehicles. When power is applied to the electro-mechanical brake, the leadscrew freewheels and allows manual compression of the actuator to return the expandable room to its highway travel position.

An aircraft engine nacelle door operating system locking manual drive unit includes a housing, an input drive shaft, an output drive shaft, a lock shaft, and a lock spring. The input drive shaft, the output drive shaft, and the lock shaft are all rotationally mounted in the housing. The output drive shaft continuously engages and mates with the input drive shaft, and he lock shaft extends at least partially into and engages the input drive shaft. The lock shaft is movable between a lock position, in which it engages and mates with the output drive shaft, and an unlock position, in it is disengaged from the output drive shaft. The lock spring supplies a bias force to the lock shaft that urges the lock shaft toward the lock position.

Provided is a non-excitation operable electromagnetic brake that includes a manually operable rotary cam for switching over a rotor to a brake releasing state, but that allows easy recognition of switchover to the brake released state via an operation reaction force and that also allows reliable keeping of the rotary cam under its acting state. Even when an electromagnet is under a non-excited state, when a rotary cam is rotatably operated to an acting position, an acting portion of the rotary cam slidably operates a rotor via a releasing plate to a brake releasing state against springs. The acting portion of the rotary cam is formed linear along a tangent at a center of the acting portion with respect to a rotary cam rotational direction.

An electromechanical actuator includes a first electric motor, a first motion conversion mechanism, a second motion conversion mechanism, and a rotation restriction mechanism for the second motion conversion mechanism. The first motion conversion mechanism includes a first member that is rotated by an output of the first electric motor and a second member that is fastened to the first member. The second motion conversion mechanism includes a third member that is movable integrally with the first member and a fourth member that is fastened to the third member. The rotation restriction mechanism is configured to be capable of selectively restricting and allowing rotation of the fourth member in accordance with movement of the third member.

A product may include a rotating sheave that may have a first sheave half and a second sheave half. A distance between the first and second sheave halves may be variable. A screw actuator may have a screw that may engage the first sheave half. A motor may be connected with the screw and may be operable to move the first sheave half to vary the distance through the screw.

The invention relates to a method for locking a mobile element (101) of an aircraft, such as a hold door or a landing gear, the mobile element being moved between a deployed position and a closed or retracted position by means of an actuator (200) having a sliding stem (3) coupled to the mobile element, the stem being mounted so as to be able to slide in a body (1) of the actuator between an extended position corresponding to the deployed position of the mobile element and a withdrawn position corresponding to the closed or retracted position of the mobile element. The method of the invention comprises the step of positively blocking the sliding stem of the actuator in the withdrawn position.

A screw type linear actuator that includes a system for automatically fixing the nut in an axial position when it is retracted. When the system is commanded to operate the screw, the nut can automatically unlock. When the system screw is retracted fully, it automatically engages a mechanical lock. The lock does not require electrical power to remain engaged.