A linear actuator (10, 10') comprising: a motor having an output shaft for producing a bi-directional rotational output; a casing (40, 140) having a tubular portion being open at both a proximal end and at a distal end, the tubular portion having an inner cavity defining a joint surface; a threaded shaft within the inner cavity of the casing(40, 140); an end block (50, 150) connected to a proximal portion of the casing (40, 140) and to the motor, the end block (50, 150) having a tubular portion defining a counterbore adjacent to a distal end thereof; at least one bearing within the inner cavity and seated and retained in the counterbore of the end block; a coupling assembly for coupling the output shaft of the motor to the threaded shaft, the coupling assembly having at least a first coupling component receiving the rotational output from the motor, and at least a second coupling component coupled to the first coupling component for transmission of the rotational output to the threaded shaft; a sliding tube (60, 160) in sliding arrangement with the inner cavity of the casing (40, 140) for moving in translation relative to the casing, a traveling nut in the sliding tube for moving therewith, the traveling nut being operatively engaged to the threaded shaft for converting a rotational motion of the threaded shaft into a translation of the sliding tube; characterized in that the linear actuator is configured to be used with motion simulators or in motion simulation to displace an occupant of a motion platform relative to the ground or a base, whereby the casing (40, 140) of the linear actuator (10, 10') has connection means on an outer surface of the tubular portion between the proximal end and the distal end configured for connection of the casing to one of a motion platform and a base or the ground, the linear actuator further comprising an end interface exterior to the casing (40, 140) and releasably connected to a distal end of the sliding tube (60, 160), the end interface having connection means to connect the linear actuator (10, 10') to the other one of the motion platform or the base or ground; and in that the linear actuator further comprises an integral assembly unit comprising the motor, the threaded shaft, the end block (50,150), the at least one bearing, the traveling nut and the sliding tube interconnected to one another so as to be separable by pulling out the integral assembly as a whole from the inner cavity of the casing via the proximal end, while the casing remains connected to the motion platform or to the base or ground through said connection means. a motor having an output shaft for producing a bi-directional rotational output; a casing (40, 140) having a tubular portion being open at both a proximal end and at a distal end, the tubular portion having an inner cavity defining a joint surface; a threaded shaft within the inner cavity of the casing(40, 140); an end block (50, 150) connected to a proximal portion of the casing (40, 140) and to the motor, the end block (50, 150) having a tubular portion defining a counterbore adjacent to a distal end thereof; at least one bearing within the inner cavity and seated and retained in the counterbore of the end block; a coupling assembly for coupling the output shaft of the motor to the threaded shaft, the coupling assembly having at least a first coupling component receiving the rotational output from the motor, and at least a second coupling component coupled to the first coupling component for transmission of the rotational output to the threaded shaft; a sliding tube (60, 160) in sliding arrangement with the inner cavity of the casing (40, 140) for moving in translation relative to the casing, a traveling nut in the sliding tube for moving therewith, the traveling nut being operatively engaged to the threaded shaft for converting a rotational motion of the threaded shaft into a translation of the sliding tube; characterized in that the linear actuator is configured to be used with motion simulators or in motion simulation to displace an occupant of a motion platform relative to the ground or a base, whereby the casing (40, 140) of the linear actuator (10, 10') has connection means on an outer surface of the tubular portion between the proximal end and the distal end configured for connection of the casing to one of a motion platform and a base or the ground, the linear actuator further comprising an end interface exterior to the casing (40, 140) and releasably connected to a distal end of the sliding tube (60, 160), the end interface having connection means to connect the linear actuator (10, 10') to the other one of the motion platform or the base or ground; and in that the linear actuator further comprises an integral assembly unit comprising the motor, the threaded shaft, the end block (50,150), the at least one bearing, the traveling nut and the sliding tube interconnected to one another so as to be separable by pulling out the integral assembly as a whole from the inner cavity of the casing via the proximal end, while the casing remains connected to the motion platform or to the base or ground through said connection means.