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.

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.

Disclosed are a multifunctional electric recirculating ball steering system for commercial vehicles and a control method thereof, including: an electric power module, a mechanical transmission module and a control module; the electric power module includes: a dual-rotor motor module (14) and a power motor (22); the mechanical transmission module includes: a steering wheel (1), a steering shaft (4), couplings (5), a recirculating ball steering gear (16), a gear sector (19), a gear sector shaft (6), a steering drag link (7), a steering tie rod (12), a steering knuckle arm (8), a left tie rod arm (11), a right tie rod arm (26), a left steering knuckle (10), a right steering knuckle (25), a left wheel (9) and a right wheel (24); and the control module includes: an electronic control unit (21), torque sensors (3), a vehicle speed sensor (20), a steering angle sensor (2) and current sensors (23). The system ensures system reliability.

Disclosed are a multifunctional electric recirculating ball steering system for commercial vehicles and a control method thereof, including: an electric power module, a mechanical transmission module and a control module; the electric power module includes: a dual-rotor motor module (14) and a power motor (22); the mechanical transmission module includes: a steering wheel (1), a steering shaft (4), couplings (5), a recirculating ball steering gear (16), a gear sector (19), a gear sector shaft (6), a steering drag link (7), a steering tie rod (12), a steering knuckle arm (8), a left tie rod arm (11), a right tie rod arm (26), a left steering knuckle (10), a right steering knuckle (25), a left wheel (9) and a right wheel (24); and the control module includes: an electronic control unit (21), torque sensors (3), a vehicle speed sensor (20), a steering angle sensor (2) and current sensors (23). The system ensures system reliability.

A power assisted steering system provides a gear reduction between a steering wheel and a steering mechanism and a much larger gear reduction between an electric motor and a steering mechanism. The system is back-driveable from the steering mechanism. The system utilizes a ball-screw, several helical gears, and two bevel gears. A rack fixed to the ball-screw nut drives a sector gear.

An apparatus for use in turning at least one steerable vehicle wheel includes a steering member rotatably supported in a housing. The steering member rotates relative to the housing about a first axis to effect turning movement of the at least one steerable vehicle wheel. A ball nut is connected with an externally threaded portion of the steering member. The steering member is rotatable relative to the ball nut assembly to axially move the ball nut assembly relative to the housing. An electric motor is operable to apply a rotational force to the steering member to urge the steering member to rotate relative to the housing. The electric motor has an output shaft extending along a second axis extending generally parallel to the first axis. A first gear is rotatable about the second axis with the output shaft of the motor. A second gear in meshing engagement with the first gear is rotatable about a third axis extending transverse to the second axis. A third gear is rotatable with the second gear about the third axis. A fourth gear in meshing engagement with the third gear is rotatable with the steering member relative to the housing.

An apparatus for use in turning steerable vehicle wheels includes a rotatable output shaft. A first rotational input assembly is provided for transmitting a steering command from a steering control member to the output shaft. A power transmitting mechanism is configured to transmit the rotational force from the input assembly to the output shaft. The power transmitting mechanism includes a plurality of sector gears. A ball screw has longitudinally separated first and second ball screw ends. A ball nut has a plurality of rack gears. Rotational force from the input assembly turns the ball screw, and the ball nut reciprocates within the housing responsive to rotation of the ball screw to move each of the plurality of rack gears in a longitudinal direction. Longitudinal motion of the rack gear teeth responsively drives the sector gear teeth to transmit the steering command to the output shaft.

A rack housing and a reduction drive housing accommodate a ball screw mechanism and a reduction drive. Within the rack housing and the reduction drive housing, a gap is provided between the left end of a nut and the rack housing, and a gap is provided between the right end of the nut and the rack housing. A groove serving as a communication path in communication with the gaps on both axial sides of the nut is provided in the outer circumferential surface of the nut. The groove is provided so as to avoid a recirculation path provided in the nut. The groove is provided axially and rectilinearly from the end of the nut that is located on the side opposite to a flange, to the flange and is provided along the flange.

A production method of a ball screw device is provided. The ball screw device includes a ball screw portion, a ball nut, rolling balls, and a retainer. The production method of the ball screw device includes: a first preparation step of preparing a nut subassembly as a standard product; a second preparation step of preparing the ball screw portion in plurality by types as ranked products; a measuring step of measuring a relative displacement in a thrust direction between the standard product and each ranked product; a determination step of determining whether the displacement meets a displacement specification; a replacing step of, if the displacement does not meet the specification, replacing the ranked product with another ranked product; and an assembling step of, if the displacement meets the specification, assembling the standard product and the ranked product into the ball screw device.

A production method of a ball screw device is provided. The ball screw device includes a ball screw portion, a ball nut, rolling balls, and a retainer. The production method of the ball screw device includes: a first preparation step of preparing a nut subassembly as a standard product; a second preparation step of preparing the ball screw portion in plurality by types as ranked products; a measuring step of measuring a relative displacement in a thrust direction between the standard product and each ranked product; a determination step of determining whether the displacement meets a displacement specification; a replacing step of, if the displacement does not meet the specification, replacing the ranked product with another ranked product; and an assembling step of, if the displacement meets the specification, assembling the standard product and the ranked product into the ball screw device.