An actuator includes a housing, an extension arm, and a threaded spindle. The threaded spindle is mounted on the housing in such a way as to be rotatable with respect to an axis of rotation by a first rotary bearing. The extension arm projects out of the housing in such a way that it can be moved in a direction of the axis of rotation. The housing and the extension arm together delimit an internal space, the volume of which changes when the extension arm moves. A first end of the threaded spindle that is remote from the first rotary bearing, projects into a tubular section of the extension arm, irrespective of a position in which the extension arm is situated. The tubular section extends with a constant internal cross-sectional shape along the axis of rotation.

A ball screw nut has a pair of through holes and a first passage that allows the through holes to communicate with each other and that opens radially outward. In each of the through holes, a ball screw mechanism has a circulation member having a second passage in which a ball can move between a ball raceway and the first passage. The ball screw mechanism has a circulation path for communicating the two connection points set on the ball raceway by the first passage and each of the second passages. A driven pulley has a thin portion that defines a radial clearance between an inner periphery of the driven pulley and an outer periphery of the ball screw nut. The ball screw mechanism has a pressing lid that presses down each of the circulation members from the outer periphery of the ball screw nut and that covers the first passage.

The present embodiments provide a rack-driven power assisted steering apparatus including a rack bar having an outer circumferential screw groove formed, a ball nut having an inner circumferential screw groove and a pair of first and second ball circulation holes, a nut pulley provided with a space on the inner circumferential surface spaced apart from the outer circumferential surface of the ball nut and coupled to an end of the ball nut, and a return tube disposed between the outer circumferential surface of the ball nut and the inner circumferential surface of the nut pulley.

A linear actuator, a housing for such a linear actuator, an actuation system, and a method for assembling a linear actuator. The linear actuator has an actuating mechanism and a housing. The actuating mechanism includes a spindle and a nut and it is configured to convert rotational motion into translational motion. The housing has two housing parts and the actuating mechanism is at least partially arranged in the housing. The two housing parts form a plurality of separate cavities that are configured to receive separate components of the linear actuator, in particular of the actuating mechanism.

A chassis actuator (1), in particular for a rear axle steering system, includes a rotational-linear transmission (5) which is provided for coupling, on the output side, to a chassis element, wherein a rotatable, input-side element (9) of the transmission (5) is mounted in a housing (13) by means of at least one axial bearing (16, 17). The transmission (5) is self-lockingly set by means of an adjustable preloading device (21), which loads the axial bearing (16, 17) with an axial force.

An electromechanical transmission and/or clutch actuator includes an electric motor for generating a driving rotational movement of a motor shaft, and elements for transmitting the driving rotational movement via a flexible drive from the electric motor to a spindle drive configured to convert the rotational movement to an axial actuation movement. The elements for transmitting the driving rotational movement may include a driving element such as a driving pulley or gear connected coaxially to the motor shaft, a driven element wheel such as a driven pulley or gear connected to the spindle drive, and a flexible element such as a drive belt which transfers the driving rotational movement from the motor shaft to the spindle drive.

A slide screw tuner movement control mechanism uses two horizontal stepper motors driving the ACME lead screw, which controls the horizontal position of the mobile carriage moving the tuning probe along the slabline. Each motor is linked with the ACME using different gear ratio, designed for coarse and fine horizontal increment (step size). This allows making ultra-wideband tuners with Fmax:Fmin>10:1 for optimized tuning speed at low frequencies and high tuning resolution at high frequencies. Appropriate calibration and optimized movement algorithms extract the best compromise between speed and tuning resolution.

The present embodiments provide a steering apparatus for vehicle including a motor pulley coupled to the rotation shaft of the driving motor, a nut pulley coupled to the outer circumferential surface of the ball nut, a belt connecting the motor pulley and the nut pulley, a first groove provided on an outer peripheral surface of at least one of the motor pulley and the nut pulley, a second groove provided on an inner surface of the belt at a position opposite to the first groove, and a slip preventing member coupled to the first groove.

A power strut assembly for raising and lowering a panel of an automotive vehicle includes a strut housing defining two parallel axes, i.e. a motor rotary axis and a spindle rotary axis. A drive motor disposed in the strut housing has an output shaft rotatable by the drive motor about the motor rotary axis. A drive spindle with a threaded section at least partially disposed in the strut housing is rotatable about the spindle rotary axis to move a spindle nut on the threaded section of the drive spindle. A motor-spindle transmission for transmitting a rotation of the output shaft to the drive spindle includes a motor wheel secured to the output shaft and a spindle wheel rigidly coupled to the drive spindle. The motor wheel and the spindle wheel extend in a common plane of rotation.

According to the embodiments, it is possible to mitigate noise by compensating for the clearance inside the bearing supporting the rotation of the ball nut and the clearance between the ball nut and the ball screw and prevent excessive friction between the ball nut and the ball screw and inside the bearing to thereby allow the driver a better steering feel.