A rear wheel steering apparatus may include: a driving part housed in a housing part; a rotating part rotated by the driving part; a moving shaft part connected to tie rods, and screwed to the rotating part; a spline plate spline-coupled to the moving shaft part so as to restrict rotation of the moving shaft part; and a space maintaining part protruding from the moving shaft part or the spline plate, and maintaining a space between the moving shaft part and the spline plate.

A ball screw mechanism includes a ball nut member that threadedly engages with a rack shaft via a plurality of balls, and a rolling bearing including an outer ring retained by a housing, an inner ring retained by the ball nut member, and a plurality of rolling elements. The ball screw mechanism moves the rack shaft in an axial direction relative to the housing through rotation of the ball nut member. A method for inspecting the ball screw mechanism includes fixing the outer ring to a fixing jig, pressing the rack shaft in the axial direction while restricting its rotation to rotate the ball nut member together with the inner ring relative to the outer ring, measuring an amount of a run-out of the rack shaft along with the rotation of the ball nut member, and determining whether the amount of the run-out satisfies a predetermined condition.

A steering gear for a steer-by-wire steering system of a motor vehicle may include a hollow shaft motor with a stator that is fixed to a housing and a rotatably supported rotor that is arranged coaxially with respect to a longitudinal axis. A worm gear may extend through the rotatably supported rotor. The worm gear comprises a spindle nut that is arranged coaxially relative to the longitudinal axis, that is connected in terms of driving to the rotor, and that is located on a spindle that is displaceable by way of the hollow shaft motor along the longitudinal axis. The angle of inclination of the worm gear may be less than 4.5?.

A steering system equipped with a linear electric actuator includes: a casing, a shaft slidably coupled to the casing with respect to a sliding axis and provided with an end that protrudes externally from said casing, an electric motor, which is housed in the casing and provided with a stator and a rotor that is axially hollow and coaxial with the shaft, in which the rotor is operable in rotation with respect to an axis of rotation parallel to the sliding axis, a nut screw integrated in rotation with the rotor of the motor and provided with an internal thread, the nut screw includes a first cylindrical portion and a second cylindrical portion, axially arranged side by side, a joint adapted to make the first cylindrical portion and the second cylindrical portion integrated in rotation, and a helical groove surface integrated with the shaft and coupled to the internal thread.

A utility vehicle steering system includes a steering gear for transmitting a manual torque from a steering wheel to a steering drop arm. An electric motor provides an auxiliary torque for the steering boost, which is provided exclusively electrically over the entire operating range of the steering system. An input shaft and an output shaft have axes of rotation that are skewed with respect to each other. A first gear device couples the input shaft to the output shaft. A second gear device has the electric motor connected to the input side and has at least one speed-reduction gear stage in the form of a coaxial gear with a high transmission ratio. The output side of the second gear device is coupled to the output shaft and its speed reduction gear stage, a coaxial gear with a high transmission ratio, is coaxial with the output shaft.

It is an object of the present invention to provide a rear wheel steering device of which the weight is not added to unsprung weight, and which can steer right and left rear wheels independently of each other. The rear wheel steering device includes a first rod connected to the left rear wheel, a first driving portion configured to axially move the first rod, a second rod connected to the right rear wheel, and a second driving portion configured to axially move the second rod. A single housing supports the first rod, the first driving portion, the second rod, and the second driving portion.

A steering control apparatus is provided which allows mitigation of an adverse effect of a technique for fixing a regulation member to a vehicle body on a phenomenon resulting from execution of steering operation control on steered wheels. An axial-force acquisition processing circuit calculates a rack axial force based on currents iu, iv, and iw flowing through a steering operation motor. A correction processing circuit corrects a target steered angle based on the rack axial force to obtain a target steered angle. A steered angle control processing circuit calculates a torque command value as the amount of operation for adjusting a steered angle to the target steered angle through feedback control. An operation signal generation processing circuit controllably adjusts a torque of a steering operation motor to the torque command value.

Provided are a low-cost ball screw device having a low-cost deflector, wherein the deflector is formable by simple machining, is easy to handle after being machined, and thus is easy to store and mount to another component. A ball screw device includes a screw shaft, a nut, rolling elements, and deflectors. Mounting holes each have a pair of circumferentially facing surfaces that face toward each other in the circumferential direction of the nut and parallel to each other. When a plane passing through the center point of an opening in one end of a second circulation path in each of the pair of deflectors and the axis of the nut is defined as a reference plane, an intersection line between an imaginary perpendicular plane perpendicular to the axis and the pair of circumferentially facing surfaces has an angle with respect to the reference plane.

A steering apparatus for an automobile according to the exemplary embodiment of the present invention includes: a steering housing in which a steering drive unit, which moves a left tie rod and a right tie rod to the left and right sides, is disposed; a left mounting bracket which is coupled to a left side of the steering housing and coupled to a left lower arm; and a right mounting bracket which is coupled to a right side of the steering housing and coupled to a right lower arm.

A linear electric actuator for steering systems includes: a casing, an electric motor, housed in the casing, which is provided with a stator and a hollow rotor internally concentric to the stator, a holder nut internally fixed to the rotor, and a stem having a thread coupled to the holder nut. The stem includes a first portion provided with a surface treatment, which projects outside the casing, and a second portion without said surface treatment, which is contained inside the casing and in which the thread is obtained.