A ball screw assembly includes a screw shaft along which is formed a first helical groove; a nut along which is form a second helical groove; the first helical groove and the second helical groove cooperating to define a track, a plurality of balls arranged in the track and configured to move along the track in response to relative motion between the screw shaft and the nut such that rotational motion of the screw is translated to linear motion of the nut via the balls and vice versa. The assembly also includes a bypass shoe arranged between the nut and the track and spaced from the track by a predetermined preload X, wherein when a load applied to the nut exceeds the predetermined preload, the bypass shoe engages with the track such that motion of the screw is transferred to motion of the nut via the shoe and bypasses the balls.

A spindle nut (S) for a ball screw is conventionally designed as a hollow cylinder with a central-symmetrical middle longitudinal axis (Z). The spindle nut has an internal thread, which is designed as a ball groove (K) arranged on the cylinder inner surface. Pairs of load-relief bores (B) serve as substantially cylindrical channels for guiding the balls out of and into the ball channel (K) through the wall of the spindle nut. Each load-relief bore (B) is distinguished by a generatrix (L), which has an intersection point (C) with the thread base line of the ball channel (K) and constitutes the geometric continuation of the traveling path of a ball from the ball channel (K) into the load-relief bore (B). A tangent (T) to the cylinder surface (G) runs in a parallel manner at a spacing a >0 to the generatrix (L), both T and L being perpendicular to a common normal (R) to the middle longitudinal axis (Z).

A steering system includes a steered shaft, a ball screw nut, balls, a housing, a rolling bearing, and a snap ring configured to prevent the rolling bearing from detaching from the ball screw nut. The rolling bearing includes double-row rolling element arrays, an outer ring, a first inner ring, and a second inner ring. The ball screw nut has a receiving portion. The snap ring contacts a side face of the second inner ring to push the second inner ring toward the receiving portion via the first inner ring. A resistance force received from the second outer peripheral fitting surface when the second inner ring moves in the axial direction in a state in which detachment of the rolling bearing is not prevented by the snap ring is smaller than a pushing force with which the snap ring pushes the second inner ring.

An external circulation ball screw includes: a screw shaft; a nut sleeved on the screw shaft and including a through hole having an opening end; and a return member mounted on the nut, and including a return groove having a return section and a continuation section, one end of the return section connected to the through hole including a connecting end which abuts against the opening end. The opening end and the connecting end are non-tangentially connected, the return section circles around a reference point, the outer wall surface of the return section is arc-shaped and centered on the reference point, a distance between the outer wall surface and the reference point is a radius of curvature, and the radius of curvature is greater than or equal to 1.2 times the ball diameter, but is less than or equal to 1.5 times the ball diameter.

A ball screw assembly having a ball screw nut including an outer surface, an inner surface defining a central bore, and a ball track defined by the inner surface, a ball screw shaft including an outer surface defining a ball track, the ball screw shaft being disposed in the central bore so that the two ball tracks form a ball raceway, a first stopper disposed at a first end of the ball screw nut within the ball raceway, a plurality of main balls forming a ball train disposed in the ball raceway, a main spring assembly disposed in the ball raceway between a first end of the ball train and the first stopper, and a strain sensing element affixed to a flat surface portion defined by the outer surface of the ball screw nut.

An improved steering shaft assembly is provided. The steering shaft assembly further includes an output shaft that is rotatable with respect to the input shaft. The output shaft includes a rotary valve portion and a longitudinal portion. The steering shaft assembly further includes a torsion bar coupled to the input shaft and coupled to the output shaft distal from the input shaft. The steering shaft assembly further includes a mid-coupler extending around about the longitudinal portion of the output shaft and adapted to cooperate with the rotary valve portion of the output shaft. The steering shaft assembly further includes a screw mechanism extending about the longitudinal portion of the output shaft and adapted to cooperate with the mid-coupler. The screw mechanism is adapted to move laterally relative to the output shaft to maintain transfer of power from between output shaft and the screw mechanism despite misalignments therebetween.

Described is a mechanical transmission (T) comprising a containment structure (1) housing a roto-translational element (2), extending along an axis of rotation (X) and comprising a first and a second threaded portion (3, 4), a rotary element (5) connected or connectable to a drive unit to define a mechanical power input unit and equipped with a first thread (8) designed to engage rotatably with the first threaded portion (3) to the roto-translational element in such a way as to define a first threaded connection, a fixed guide (9) having a second thread (14) designed to engage with the second threaded portion (4) of the roto-translational element (2) in such a way as to define a second threaded connection, and a translating element (10), translating along the axis (X) and defining a power output unit. The translating element (10) is connected to the roto-translational element (2) for translating at the same linear speed as the roto-translational element (2). The roto-translational element (2) is thus simultaneously coupled to the rotary element (5) and to the fixed guide (9) respectively by means of the first and second threaded connections. These connections have different pitches in such a way as to vary the angular speed between the roto-translational element (2) and the rotary element (5).

A ball screw drive includes two screw drive parts (3, 4), namely a lead screw (3) and a nut (4). The ball screw drive also includes a deflection element (6) for the individual deflection of balls (5) is inserted into a recess (7), formed by one of the screw drive parts (3, 4), such that a gap (16) is formed between the base (15) of the recess (7) and the deflection element (6), and such that lateral contact surfaces (17) of the deflection element (6) which are located next to the recess (7) rest on the screw drive part (3, 4).

A ball screw device includes a screw shaft having a first screw groove formed on an outer circumference thereof, a ball screw nut having a second screw groove formed on an inner circumference thereof, and a plurality of balls disposed in a spiral ball raceway wherein the first screw groove and the second screw groove face each other. A circulation member is attached to an attachment hole radially penetrating the ball screw nut and a circulation path is formed, the circulation path allowing endless circulation of each of the balls rolling in the ball raceway by short-circuiting between two points of the ball raceway.

A ball return tube for connecting openings of a ball nut to circulate balls comprises tube end portions for being coupled to the openings of the ball nut, and a tube body connecting the tube end portions so that the balls can pass through the tube body. The ball return tube is constructed in first and second tube portions fixedly joined together by structures included in a first projection protruding from a first surface of the tube body. The ball return tube further comprises one or more of a second projection protruding from a second surface of the tube body in a direction toward the ball nut, a third projection protruding from a lateral side surface of the tube body, and a fourth projection protruding from the tube open end portions so that the projections can be coupled to corresponding recesses of the ball nut.