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.

The ball screw device includes: a screw shaft having an N number (N is an integer equal to or larger than 2) of rolling grooves having the same lead; balls configured to roll in the rolling grooves; and a nut member, which is assembled to the screw shaft through intermediation of the balls, and includes one or a plurality of endless circulation paths configured to circulate the balls around the screw shaft. Each of the endless circulation paths of the nut member includes: an N number of load portions, which are configured to allow the balls to roll thereon while bearing a load, and correspond to the N number of rolling grooves, respectively; and an N number of no-load portions, which each couple adjacent ones of the load portions, and are configured to allow the balls to move between the N number of rolling grooves.

A method for producing a spindle nut (10) for a ball screw (12) is provided, having the following steps: providing a substantially cylindrical workpiece (50) with first and second end faces (46, 44) and a lateral surface (14), shaping the workpiece (50) by pressing in an axially symmetrical central opening (16) and by simultaneously pressing in at least one first (18) and one second (20) channel which are arranged axially in parallel in the lateral surface (14) of the workpiece (50), the central opening (16) and the channels (18, 20) being open toward the first end face (46), introducing an internal thread (34) into the central opening (16), and introducing at least two radially running through-openings (22, 24) at least into the first channel in the form of a transfer channel for receiving diverting inserts (26, 28). A spindle nut (10) produced by the method and to a ball screw (12) having such a spindle nut (10) are also provided.

A rack assist electric power steering apparatus. Shock between a rotary support member and a housing is absorbed. Backlash and friction in the rotary support member are reduced. The length of a ball nut is minimized, and the rotary support member is supported by a portion in which the ball nut and a rack bar are coupled, so that noise is reduced.

A ball screw device has a screw shaft; a nut; a circulation part; and balls; a housing concave groove provided on the outer circumferential surface of the nut and linearly extending in the axial direction and opening to end surfaces on both outer sides in the axial direction of the nut, a circulation part arranged inside the housing concave groove, and the circulation part being prevented from displacing toward the outer side in the radial direction and displacing in the circumferential direction with respect to the nut by engaging an engaging convex portion of a fixing portion provided in the end portion on each of both outer sides in the axial direction of the circulation part with an engaging recess portion provided in the end portion of each of both outer sides in the axial direction of the housing concave groove.

An electric actuator for a steering system is adapted to control an angle of steered wheels on a vehicle to adjust a direction of travel of the vehicle. The electric actuator includes a housing assembly, an electric motor, and an actuation unit. The housing assembly is arranged around the electric motor and the electric motor is coupled with the actuation unit and configured to cause an actuator rod of the actuation unit to move relative to the housing assembly.

A ball-screw drive for an actuator assembly of a vehicle brake is disclosed, comprising a rotatably mounted recirculating ball screw on which a screw nut which is closed on one side is mounted, at least one thread being formed on the circumferential surface of the recirculating ball screw, in which thread a plurality of balls are guided in such a way that a rotation of the recirculating ball screw brings about an axial displacement of the screw nut along an axis of rotation of the recirculating ball screw. A ball return system is integrated in the recirculating ball screw. Furthermore, an actuator assembly comprising a ball-screw drive and a method for producing a ball-screw drive are indicated.

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.

An electric actuator for a steering system is adapted to control an angle of steered wheels on a vehicle to adjust a direction of travel of the vehicle. The electric actuator includes a housing assembly, an electric motor, and an actuation unit. The housing assembly is arranged around the electric motor and the electric motor is coupled with the actuation unit and configured to cause an actuator rod of the actuation unit to move relative to the housing assembly.

A ball screw device including a low-cost retainer that is disposed between a ball screw shaft and a ball nut and has a flange portion, a steering system using the ball screw device, and a method for producing the retainer of the ball screw device are provided. The ball screw device includes the ball screw shaft, the ball nut, rolling balls, and the retainer. Both side surfaces of each of retainer grooves are formed so as to allow radially outward movement of the rolling balls and to restrict radially inward movement thereof, and the retainer has a weld joint at both of the opposite ends of each retainer groove in the axial direction of the retainer.