An electric power steering apparatus according to the embodiments of the present disclosure may comprise a ball screw having an outer screw groove formed on its outer circumferential surface, a ball nut having a gear portion formed on one side of the outer circumferential surface and an inner screw groove corresponding to the outer screw groove formed on the inner circumferential surface, coupled to the ball screw through a ball and sliding in the axial direction, a sector shaft having a shaft gear coupled to the gear portion of the ball nut on an outer circumferential surface and rotating when the ball nut slides in an axial direction, and a sliding support member coupled to the outer circumferential surface of the ball nut, supported on an inner circumferential surface of a housing, and axially slid together with the ball nut.

A turning device includes a turning shaft having a first ball screw groove as one of a left screw and a right screw and a second ball screw groove as the other of the left screw and the right screw and turning wheels to be turned by moving in an axial direction, a first electric motor generating a first driving force, a second electric motor operating independently of the first electric motor and generating a second driving force, a first ball screw nut transmitting the first driving force generated by the first electric motor to the first ball screw groove, a second ball screw nut transmitting the second driving force generated by the second electric motor to the second ball screw groove, and a rotation regulating part regulating relative rotation of the turning shaft around an axis with respect to a housing.

A turning device includes a turning shaft having a first ball screw groove as one of a left screw and a right screw and a second ball screw groove as the other of the left screw and the right screw and turning wheels to be turned by moving in an axial direction, a first electric motor generating a first driving force, a second electric motor operating independently of the first electric motor and generating a second driving force, a first ball screw nut transmitting the first driving force generated by the first electric motor to the first ball screw groove, a second ball screw nut transmitting the second driving force generated by the second electric motor to the second ball screw groove, and a rotation regulating part regulating relative rotation of the turning shaft around an axis with respect to a housing.

An electric power steering apparatus and a control method thereof. A motor includes a first motor providing power to move a rack and a second motor providing power to move the rack in synchronization with the first motor. A sensor includes a torque angle sensor detecting a torque value and a steering angle in response to manipulation of a steering wheel and an angle sensor detecting an angle of rotation of a sector shaft. A controller controls the motor in response to the manipulation of the steering wheel, calculates an amount of compensation rotation of the motor by comparing the steering angle and the angle of rotation, and controls an amount of rotation of the motor in accordance with an amount of compensation rotation. The amount of rotation of a vehicle's wheel is controlled, so that actual intention of the driver in steering is accurately reflected.

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.

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.

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.

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.

In a power steering system employing an end of travel system including valve actuating rings disposed about a Pitman arm shaft, a device is provided for setting the positions of the rings on the shaft. The device includes a fixed member positioned about, and fixed against movement along, a longitudinal axis perpendicular to the shaft's rotational axis and a movable member that moves along the longitudinal axis relative to the fixed member. The movable member defines a pin at one end configured for engagement with the circumferential ends of the actuating rings. A positioning force applied to one of the members causes the movable member to move between set and reset positions in which the pin engages corresponding ends of the actuating rings during rotation of the shaft and a running position in which the pin remains disengaged from the ends of the actuating ring during rotation of the shaft.

In a power steering system employing an end of travel system including valve actuating rings disposed about a Pitman arm shaft, a device is provided for setting the positions of the rings on the shaft. The device includes a fixed member positioned about, and fixed against movement along, a longitudinal axis perpendicular to the shaft's rotational axis and a movable member that moves along the longitudinal axis relative to the fixed member. The movable member defines a pin at one end configured for engagement with the circumferential ends of the actuating rings. A positioning force applied to one of the members causes the movable member to move between set and reset positions in which the pin engages corresponding ends of the actuating rings during rotation of the shaft and a running position in which the pin remains disengaged from the ends of the actuating ring during rotation of the shaft.