The present embodiments provide a rack-driven power assisted steering apparatus including a rack bar having an outer circumferential screw groove formed, a ball nut having an inner circumferential screw groove and a pair of first and second ball circulation holes, a nut pulley provided with a space on the inner circumferential surface spaced apart from the outer circumferential surface of the ball nut and coupled to an end of the ball nut, and a return tube disposed between the outer circumferential surface of the ball nut and the inner circumferential surface of the nut pulley.

The present invention provides a power steering apparatus capable of improving a noise/vibration characteristic derived from a pitch difference. Assuming that a belt pitch refers to a pitch between a plurality of belt tooth portions, the belt pitch in a first state refers to the belt pitch when the power steering apparatus is in an unloaded state that no electric power is supplied to an electric motor, the belt pitch in a second state refers to the belt pitch on one side pulled by a motor pulley when electric power is supplied to the electric motor, and a first pulley pitch refers to a pitch between a plurality of tooth portions of a first pulley, which is one of the motor pulley and a nut pulley that is a pulley on a smaller diameter side, a power steering apparatus satisfies Equation 1: the belt pitch in the first state<the first pulley pitch, and Equation 2: an absolute value of (the first pulley pitch−the belt pitch in the second state)<the first pulley pitch−the belt pitch in the first state.

According to the present embodiments, provided is a rack-driven power assisted steering device in which a rolling member supporting the rotation of a ball nut is provided in a double row, a ball nut assembly is coupled to a housing through an elastic member, the flow of the ball nut is absorbed to improve noise performance, and the rolling member is directly supported by the ball nut or a support member, so that the number of parts can be reduced and easy assembly is possible.

A steering device includes an electric actuator that applies a steering force to one end side of a steering shaft. The other end side of the steering shaft is provided with a displacement detection part for detecting the movement amount of the steering shaft. Either a detection target or a displacement detection sensor is provided on the steering shaft and the other is provided in a housing so as to output a signal according to a relative position change amount of the detection target with respect to the displacement detection sensor in the direction of the first axis. A first restriction mechanism restricts the relative movement of the detection target and the displacement detection sensor in a radial direction regarding the first axis to limit the change in the relative position in the radial direction of the detection target and the displacement detection sensor.

A ball screw device includes a plurality of ball screw devices. In one ball screw device, a recirculation member is larger than the recirculation member in another ball screw device in terms of one mounting dimension of two mounting dimensions selected from a circumferential length of a part at a side of a pick-up opening portion in each pick-up portion, a circumferential length of a part at a side opposite to the pick-up opening portion in each pick-up portion, a circumferential length of a connection passage portion and an axial length of the connection passage portion, and the recirculation member is smaller than the recirculation member in the other ball screw device in terms of another mounting dimension of the two mounting dimensions, the other ball screw device being different in a diameter of a screw shaft from the one ball screw device.

A rack bar assembly for a rack electric power steering system is provided. The rack bar assembly includes a first rack bar extending axially. The rack bar assembly also includes a second rack bar extending axially, wherein the first rack bar and the second rack bar are spaced a radial distance from each other and oriented parallel to each other.

Belt driven rotary assist apparatus for recirculating ball steering gears are disclosed. An example motor vehicle steering system includes an input shaft to couple to a steering shaft of a motor vehicle, a worm gear, a first end of the worm gear coupled to the input shaft, a second end of the worm gear fixed to a helical spur gear, a ball nut surrounding a portion of the worm gear, the ball nut including ball bearings and ball guides, a first pulley wheel fixed to a pinion, the first pulley wheel engaged with a belt, the pinion engaged with the helical spur gear, a motor fixed to a second pulley wheel, the second pulley wheel engaged with the belt, the motor to rotate the worm gear to translate the ball nut, and a sector gear engaged with the ball nut, the sector gear to rotate as the ball nut translates.

An electric powered recirculating ball assembly includes a shaft having a plurality of sector teeth extending therefrom. The assembly also includes an eccentric sleeve defining a bore containing a portion of the shaft, the eccentric sleeve comprising an upper sleeve segment and a lower sleeve segment that are separate components, the eccentric sleeve defining an opening that the sector teeth extend through.

The present embodiments provide a steering apparatus for vehicle including a motor pulley coupled to the rotation shaft of the driving motor, a nut pulley coupled to the outer circumferential surface of the ball nut, a belt connecting the motor pulley and the nut pulley, a first groove provided on an outer peripheral surface of at least one of the motor pulley and the nut pulley, a second groove provided on an inner surface of the belt at a position opposite to the first groove, and a slip preventing member coupled to the first groove.

Methods and apparatus to determine rack force are disclosed. An example apparatus includes a rack to couple to a steering knuckle of a vehicle, a ball nut engaged with the rack, a first ring gear coupled to the ball nut, a first pinion fixed to a motor, the first pinion engaged with the first ring gear, the motor to rotate the ball nut to move the rack, a motor encoder to detect a rotation of the first pinion, a second ring gear coupled to the ball nut, and a sensor fixed to a second pinion, the second pinion engaged with the second ring gear, the second pinion to rotate as the second ring gear rotates, the sensor to detect a rotation of the second pinion, the rotation of the second pinion and the rotation of the first pinion corresponding to a force on the rack.