The invention relates to a roller screw mechanism comprising a screw (110) provided with an external thread; a nut (130) coaxially surrounding the screw (130) and provided with an internal thread; and rollers (120), each of which is provided with an external thread, each roller (120) being interposed between the screw (110) and the nut (130) so that the threads of the rollers mesh with the threads of the screw and of the nut; said roller screw mechanism being characterized in that the threads of the rollers are complementary to the threads of the screw and of the nut so that, at zero load, the threads of the rollers co-operate on both of their flanks with the threads of the screw and of the nut in a contact geometry having curvilinear segments.

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.

A roller screw mechanism comprising a screw, provided with an outer thread, a nut positioned around and coaxially to the screw, the nut being provided with an inner thread, and a plurality of rollers inserted between the screw and the nut, each comprising an outer thread engaged with the outer thread of the screw and with the inner thread of the nut. Each of the threads of the screw, rollers and nut comprise first and second axially opposite flanks, respectively forming a first and second angle with a plane perpendicular to the central axis of the screw, the first and second flanks of each thread of the rollers respectively being in contact with the first and second flanks of the nut's thread and with the first and second flanks of the screw's thread. The value of the first angle is different from the value of the second angle.

A wave machine (8) that produces different shapes of standing, parabolic-shaped waveforms (150) used by surfers (200). The parabolic waveforms (150) have different face angles and depths. The machine (8) includes a rotating container (10) partially filled with a fluid 140. When the container (10) is rotated, a standing, parabolic waveform 150 is created in the fluid (140). In one embodiment, the container (10) is bowl container (11) with curved panels (60) and terminate at an upper edge (16). On or near the upper edge (16) of the sidewall (14) is upper flange (18) that partially extends into the bowl container (11). The bowl container (11) is coupled to a speed adjustable drive mechanism (50). As the bowl container (11) is rotated, fluid (14) is forced outward against the sidewall (14) and forms a parabolic waveform (150). As the speed of rotation is increased, the fluid (140) flows upward over the sidewall (14) and against the upper flange (18). The thickness, depth and face of parabolic waveform (150) adjacent to the sidewall (14) are increased.

A method for setting an axial preload force of a roller screw drive (3) which is rotatably mounted in a housing (2) by means of bearings (4, 5) which are axially spaced apart from one another. The housing (2) is split transversely with respect to the thrust rod (7) into a first and a second housing part (8, 9). The roller screw drive (3) is inserted with the two bearings (4, 5) into the second housing part (9). An axial preload force is applied which is transmitted from the first bearing (4) via the roller screw drive (3) to the second bearing (5). An axial load spacing (“X”) between the bearing supporting surface of the first bearing (4) and a second housing edge (31) of the second housing part (9) is measured. An adjusting nut (10) is screwed into the first housing part (8) until an axial adjustable spacing between the end-side adjusting nut supporting surface (12) and the first housing edge (30) of the first housing part (8) is the same size as the measured axial load spacing (“X”). The adjusting nut (10) is then secured in place in the first housing part (8), and the two housing parts (8, 9) are connected to one another, with the result that both bear against one another by their housing edges (30, 31).

A force actuator including an actuator housing, in which, via transmission elements, an electric motor is arranged to drive a displaceable roller screw along the longitudinal axis of the force actuator, and in which a rotatable roller cage which is in engagement with the transmission elements is provided with at least one threaded roller, the threaded roller being in threaded engagement with the roller screw, and the roller screw being prevented from rotating around the longitudinal axis.

A roller screw system includes a spindle defining a longitudinal axis about which the spindle rotates. A nut at least partially radially surrounds the spindle. The nut is configured for longitudinal motion with respect to the spindle. At least one non-helically grooved roller is interposed radially between the spindle and the nut. A cage maintains the at least one roller in position radially between the spindle and the nut and supports the at least one roller for rotational motion. The nut is moved in longitudinally in a duty cycle responsive to transmission of rotational motion from the spindle to the at least one roller, and transformation of rotational motion of the at least one roller to longitudinal motion of the nut. A home position of the nut and a home position of the cage both move longitudinally after a predetermined number of duty cycles.

A steering actuator comprising a shaft having an input coaxial with an output, wherein the output is in drivable communication with one or more wheels of a vehicle, and a locking mechanism configured to enable the shaft to rotate in both a first direction and a second direction in response to torque provided at the input, and prevent the shaft from rotating in both the first direction and the second direction in response to torque provided at the output.

A linear actuator system having an actuator housing, a motor assembly, a screw shaft, a thrust tube, and a nut assembly. The nut assembly is engaged with the screw shaft and directly coupled with the thrust tube. The nut assembly can define a mechanical fitting for direct physical engagement between the thrust tube and the nut assembly, absent additional load bearing components intervening therebetween. The nut assembly is configured to convert rotational motion of the rotor about the longitudinal axis to linear motion of the thrust tube along the longitudinal axis. A cooling loop can be at least partially embedded, potted or seated within the actuator housing, with a thermally conductive material disposed at least partially about the cooling loop to conduct heat from the actuator housing.

A roller screw mechanism is provided comprising a screw with an outer thread, and a nut disposed around and coaxially with the screw and comprising an inner thread; and with rollers that each have an outer thread and inserted between the screw and the nut, each roller having two ends each provided with an outer gear teeth, each outer gear teeth having, in cross-section, an outer diameter less than or equal to a root diameter of the outer thread of the rollers; and two synchronizing gear teeth disposed coaxially to the screw and in which the outer gear teeth of the rollers engage, wherein the outer gear teeth of the rollers have teeth with a flank having, in cross-section, a convex hypotrochoidal profile and the synchronizing gear teeth have teeth with a flank having, in cross-section, a hypotrochoidal or epitrochoidal profile.