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.

A vehicle steering system comprises: a motor assembly operably coupled to a steering rack, the motor assembly comprising a motor having a rotor and a motor position sensor configured to sense a rotor angle of the motor in a single-turn range; and a rotary-to-linear conversion mechanism operably coupled between the motor assembly and the steering rack, the rotary-to-linear conversion mechanism comprising a rotor operably coupled to the rotor of the motor. A processor calculates an absolute angular position of the pinion in a full-turn range of rotation of the pinion based on the sensed rotor angle of the motor and a pinion angle sensed by a pinion angle sensor in a single-turn range, or based on the sensed rotor angle of the motor and an angle of the rotor of the rotary-to-linear conversion mechanism sensed by an angular position sensor in the single-turn range.

A steering system (10) for a motor vehicle, which steering system (10) is configured as a steer-by-wire steering system, comprises a rack (14), an electric drive (16) for the longitudinal displacement of the rack (14), and a rotatably mounted supporting element (20) which is spaced apart from the electric drive (16) along the longitudinal axis of the rack (14), and the rotatably mounted supporting element (20) being in toothed engagement with the rack (14).

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.

A steering system includes a housing, a steering operation shaft that is housed in the housing and configured to move in an axial direction to steer right and left steered wheels, a first drive source that generates a first drive force, a second drive source that generates a second drive force, a first power transfer unit that applies an axial force to the steering operation shaft with the first drive source, a second power transfer unit that applies an axial force to the steering operation shaft with the second drive force, a position detection sensor that is provided in the housing and detects an axial position of the steering operation shaft, and a control device that controls the first drive source and the second drive source using a detection result of the position detection sensor.

According to the present embodiments, it is easy to be drawn in or out balls between the sliding bar and the ball nut. Thus, it is possible to easily replace the balls. Therefore, it is possible to easily compensate for the gap between the sliding bar and the ball nut.

A steering system to steer wheels by a movement of a steering shaft, including: the steering shaft; an electric motor; a converter configured to convert a rotational motion of the motor into the movement of the steering shaft; a motor rotation angle obtainer configured to obtain a motor rotation angle from a zero point position; a movement-amount-related-amount obtainer configured to obtain a movement-amount-related amount that is a movement amount of the steering shaft from a neutral position or a physical amount in a one-to-one correspondence with the movement amount; and a controller including a malfunction detector configured to detect a presence or absence of a malfunction of the converter in a mode that differs depending on a temperature state of the steering system, based on the motor rotation angle from the zero point position obtained by the motor rotation angle obtainer and the movement-amount-related amount obtained by the movement-amount-related-amount obtainer.

A housing for an electric power steering device that has an electric motor, a speed reduction mechanism, a ball screw mechanism, and a rack bar. The housing has a first housing having a first end portion covering a part of the rack bar and a second end portion with a portion accommodating at least a part of the speed reduction mechanism. The first housing includes a rack bar insertion hole portion; an electric motor shaft insertion hole portion having a cylindrical shape on a radially outer side of the rack bar insertion hole portion, through which an electric motor shaft is inserted; and a fastening portion having an annular shape overlapping with an inner peripheral surface of the electric motor shaft insertion hole portion along the longitudinal direction of the rack bar when an axis extending in the rack bar longitudinal direction is viewed from a radially outer side.

Provided is a power steering apparatus capable of reducing a maximumly generated stress on an output pulley. An output pulley of a power steering apparatus includes a fastening target portion around a screw insertion hole of a hub portion. When a boundary portion between the hub portion and a winding and hanging portion is defined to be a portion where a minor angle, among relative angles formed between a tangential line of an inner surface of the output pulley and a rotational axis of a nut in an axial cross section of the output pulley that passes through the rotational axis of the nut, gradually reduces from a nut-rotational-axis side toward a radially outer side to then reach 45 degrees, the fastening target portion is a region that is located on an inner side in a radial direction with respect to the boundary portion and overlaps a head portion of a screw in a radial direction of the screw.