The present embodiments may provide a steer-by-wire type steering apparatus which can significantly reduce production cost by reducing the number of components and simplifying the assembly procedure, by eliminating a pinion gear, etc., and sensing the position of a sliding bar on the basis of rotation information detected from a gear box which transfers the rotational force of a motor to the sliding bar.

The disclosure relates to a planetary roller screw having: a nut arranged on a threaded spindle and divided crosswise to a spindle axis into two nut parts; planetary rollers arranged between the threaded spindle and the nut distributed over the circumference, the planetary rollers intermeshing with the nut parts and with the threaded spindled; a rotatingly driven planetary roller carrier arranged on the threaded spindle, in pockets of which, arranged distributed over the circumference, the planetary rollers are mounted, held at a distance in the circumferential direction, so as to be rotatable about the planetary roller axis; and a housing in which the planetary roller carrier is rotatably mounted. A pre-loading device is provided in order to adjust an axial pre-load between the housing and the planetary rollers.

An electric cylinder system includes: a rod; a ball screw mechanism; a nut connected to the rod; a cylindrical body including a contact portion, the contact portion configured to be abutting the nut making the linear motion, the cylindrical body configured to support the ball screw mechanism in such a manner that the ball screw mechanism is displaceable in the axis direction of the ball screw; a strain detector fixed to the cylindrical body and configured to detect a value corresponding to a displacement of the ball screw mechanism; and a control section configured to make the ball screw mechanism be displaced by making the nut abut against the contact portion, and configured to detect an abnormality of the strain detector based on the value detected by the strain detector according to the displacement of the ball screw mechanism.

According to the present embodiments, it is possible to ensure normal steering and the driver's safety by preventing jumping without proper engagement between the teeth of the pulley and the belt.

A ball screw spline assembly includes a ball screw spline including a first nut including a first mounting surface adapted to receive a first fastening element; a second nut including a second mounting surface adapted to receive a second fastening element; and a shaft passing through the first nut and the second nut; the housing including a first portion and a second portion, the first portion extends in a direction substantially parallel to the shaft, and the second portion extends in a direction substantially perpendicular to the shaft; a connecting plate coupling the second nut to the first portion, the first nut is installed to the second portion; the first mounting surface and the second mounting surface are located within a space defined by the first portion, the second portion and the connecting plate, such that the ball screw spline is integrally installable to the housing.

Provided is a steering device including a lock nut that fixes an outer race of a turning nut threadably engaged with a rack bar. A loosening prevention protruding portion formed on a lock nut main body is brought into contact with a radial-direction abutting portion to prevent loosening of the lock nut with a frictional force. At the same time, a lock nut recessed portion for reducing mechanical stiffness is formed in an outer peripheral surface of the loosening prevention protruding portion so that an external force acting from the outer race is buffered by the lock nut recessed portion. In this manner, a decrease in contact area between the loosening prevention protruding portion and the radial-direction abutting portion is reduced.

A rack ball nut assembly for a vehicle steering gear has a ball nut, a ball return tube, and a tube retention clip. The ball nut has first and second recesses and the ball return tube has first and second tube portions. There is a snap fit between the first and second tube portions. The tube retention clip has first and second retention tabs. The first tab is engaged in the first recess and the second tab is engaged in the second recess. The ball return tube is secured between the ball nut and the tube retention clip.

A steering device includes a steering rod that includes two ball screw parts, the steering rod being configured to steer a steerable wheel by moving linearly, two ball nuts respectively fastened to the two ball screw parts, two motors each configured to generate a drive force, two transmission mechanisms each including a toothed belt, the two transmission mechanisms being configured to transmit the drive force of each one of the two motors to a corresponding one of the ball nuts, two detectors configured to respectively detect rotation angles of the two motors, and a controller configured to control each of the two motors. The controller is configured to detect tooth jumping of the belts using the rotation angles of the two motors that are detected by the two detectors.

A ball screw device and a steering system that include a retainer having more uniform stiffness are provided. Between a rack shaft and a ball screw nut, a cylindrical retainer having a plurality of retainer grooves that retain balls in a rollable manner is provided. Each retainer groove has two short inner surfaces that intersect the extending direction of the retainer groove and two long inner surfaces that intersect these short inner surfaces and extend along the extending direction of the retainer groove. In each of interior-angle portions where the short inner surfaces and the long inner surfaces intersect, a corner round surface is formed. The radius of the corner round surface is set to be smaller than one half of the width of the retainer groove.

An electric drive unit for a wheel of a motor vehicle, including an electric motor for driving a drive shaft joined to the wheel in a manner resistant to rotation. The drive shaft is disposed coaxial to the rotor of the electric motor and is joined thereto in a rotation-resistant manner. The drive shaft is joined to the rotor of the electric motor in a rotation-resistant and axially moveable manner via a bearing.