Steering actuators for vehicles are described herein. An example actuator includes a rack to be coupled to a knuckle of a vehicle, a ball nut coupled to the rack, a ring gear coupled to the ball nut, and a motor with a pinion engaged with the ring gear. The motor is to rotate the ball nut, via the pinion and the ring gear, to move the rack linearly.

A ball screw device includes a screw shaft body, a ball nut, a housing, a bearing, an annular first biasing member and an annular second biasing member, and an annular first holding member and an annular second holding member. The housing includes a cylindrical first housing and a cylindrical second housing that are coupled to each other in a surface-contact state. The first housing includes a bearing holding portion that holds the bearing slidably in the axial direction. The second housing includes a pressing portion that protrudes radially inward. At least one of the first holding member and the second holding member generates a gap between the first housing and the second housing when the bearing, the first biasing member, the second biasing member, the first holding member, and the second holding member are wrongly mounted to one another.

A steering device includes: a steered shaft; a first nut; a second nut; a first motor; a second motor; a first power transmission portion that transmits a first drive force generated by the first motor to the first nut, converts the first drive force into a force in an axial direction, and biases the steered shaft in the axial direction; a second power transmission portion that transmits a second drive force generated by the second motor to the second nut, converts the second drive force into a force in the axial direction, and biases the steered shaft in the axial direction; a signal detection device that detects a first detection signal and a second detection signal with different periods; and a computation device that computes an absolute position of the steered shaft in the axial direction.

To provide a ball screw device and a steering device capable of securing smooth circulation of balls while suppressing occurrence of clogging of the balls caused by displacement in a radial direction between a deflector and a nut main body. A ball screw device includes a ball screw nut and a circulation path. The ball screw nut includes a nut main body and a deflector. The deflector includes an inclined portion provided at a peripheral part of a connection portion between a passage and the circulation path of the nut main body for securing passing of the balls at the connection portion when an insertion position of the deflector with respect to the deflector mounting hole is displaced from a desired position within a range of a given distance.

A steering system is provided. The steering system may include a drive pulley and a ball nut assembly. The drive pulley may be operatively connected to a drive shaft. The ball nut assembly may be driven by the drive pulley via a belt disposed about the drive pulley and the ball nut assembly. The ball nut assembly may include a ball nut and a driven pulley. The ball nut may have an inner surface disposed about a ball screw that defines and extends along a first axis and an outer surface disposed opposite the inner surface. The ball nut may define a first groove that extends from the outer surface towards the inner surface. The driven pulley may be disposed about the ball nut and have a retaining member that includes a finger for extending into the first groove to engage the ball nut and driven pulley without separate fasteners.

An electric power steering system includes: a steered shaft, a housing containing the steered shaft therein in a movable manner; a ball screw nut engaged threadedly to the steered shaft via a plurality of balls and configured to move the steered shaft in an axial direction; a double row angular contact ball bearing configured to retain the ball screw nut and to support the retained ball screw nut rotatably relative to the housing; a wall portion placed at either side of the double row angular contact ball bearing in the axial direction of the steered shaft, the wall portion being formed integrally with the housing; and an elastic member provided between the wall portion and the outer ring portion and configured to retain the double row angular contact ball bearing to be elastically displaceable in the axial direction.

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 device includes: a rack shaft; a rack housing housing the rack shaft; a motor unit having a motor case of which one end is coupled to the rack housing; a moving force application mechanism that moves the rack shaft by an output of the motor unit; and a support member that is fixed to the rack housing and supports the motor case. The rack housing has a fixing projection in which a bolt hole extending in a height direction is formed. The support member has an arc-shaped support part that extends along an outer circumferential surface of the motor case, and a pair of fixing pieces that protrudes from the support part toward a rack shaft housing section. Ends of the pair of fixing pieces are fastened with a bolt to the fixing projection of the rack housing.

An electric power steering apparatus includes left and right swing arm members, right and left tie rods pivotally connected at inner ends to arm portions of the swing arm members via a relay rod pivotally connected to the arm portions at both ends, a rack-and-pinion device in which one end of a rack bar is connected to the arm portion of one of the swing arm members, and a steering input transmission system that transmits a steering input to the rack-and-pinion device. An electric steering assist force applying device is connected to the arm portion of the other swing arm member, and applies a force to assist the other swing arm member to swing.

A rack bar blank material includes a rack portion configured to mesh with a pinion in an end side of a hollow shaft material in an axial direction, and an end portion which is provided closer to the end side of the hollow shaft material than the rack portion. The end portion has a diameter which is larger than that of a minimum circle embracing a section of the rack portion which is perpendicular to the axial direction and which is equal to that of a shaft portion at the other end side of the shaft material in the axial direction.