An apparatus for use in turning steerable vehicle wheels includes a rotatable shaft that is rotatable relative to the vehicle to effect turning movement of the steerable vehicle wheels. A ball nut assembly is connected with an externally threaded portion of the rotatable shaft. The ball nut assembly moves axially relative to the rotatable shaft upon rotation of the rotatable shaft relative to the ball nut assembly. A steering member is connected to the ball nut assembly and at least one steerable vehicle wheel. The steering member moves with the ball nut assembly relative to the shaft. An electrical motor is connected with the rotatable shaft. The motor is operable to effect rotation of the rotatable shaft relative to the ball nut assembly to turn the steerable vehicle wheels.

A power-assisted steering assembly for a vehicle comprises: a motor shaft for transmitting torque from a motor; a steering rack; a primary transmission mechanism; a secondary transmission mechanism; a motor coupling; and a rack coupling. The primary transmission mechanism is configured to transmit power from the motor shaft to the steering rack and includes a drive belt. The secondary transmission mechanism is configured to transmit power from the motor shaft to the steering rack upon a failure of the primary transmission mechanism. The motor coupling is configured to transmit power from the motor shaft to the primary transmission mechanism and the secondary transmission mechanism. The rack coupling is configured to transmit power from the primary transmission mechanism and the secondary transmission mechanism to the steering rack. Prior to the failure of the primary transmission mechanism, the motor coupling and rack coupling are configured to transmit a greater amount of power to the primary transmission mechanism than to the secondary transmission mechanism.

A ball screw drive having a threaded spindle and a spindle nut which coaxially encloses it at least partially. The spindle nut receives a ball deflector and therefore has an imbalance caused thereby. A force transmission element is positively connected to the spindle nut. The outer surface of the spindle nut has a recess which is dimensioned and arranged to serve as a stop or groove for the force transmission element and also contributes to the imbalance compensation of the spindle nut. An imbalance compensation method is also provided by fixing the action surface as a surface recess such that the smallest width of the recess is at least 3 times as large as the maximum radial indentation thereof. The filling up of at least parts of the recess by the force transmission element is accounted for and the recess is lengthened along the spindle nut for imbalance reduction.

Technical solutions are described for lash detection diagnostic in a steering system. An example method includes sending, by a controller, an excitation motor command to a motor control system. The method further includes measuring, by the controller, a sensor signal generated in response to the excitation motor command. The method further includes determining, by the controller, a decay rate of a change in magnitude of the signal at a plurality of frequencies. The method further includes diagnosing, by the controller, that the steering system has a lash condition based on the decay rate exceeding a predetermined threshold.

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 steering device includes a steering rod that includes two ball screw parts, the steering rod being configured to steer a steerable wheel by moving linearly, two ball nuts respectively fastened to the two ball screw parts, two motors each configured to generate a drive force, two transmission mechanisms each including a toothed belt, the two transmission mechanisms being configured to transmit the drive force of each one of the two motors to a corresponding one of the ball nuts, two detectors configured to respectively detect rotation angles of the two motors, and a controller configured to control each of the two motors. The controller is configured to detect tooth jumping of the belts using the rotation angles of the two motors that are detected by the two detectors.

A steering device includes two motors each configured to generate a drive force that steers a steerable wheel of a vehicle and two controllers respectively corresponding to the two motors, each of the two controllers being configured to individually control a corresponding one of the motors. One of the two controllers is a first controller, and the other one of the two controllers is a second controller. The first controller is configured to calculate a command value corresponding to a total torque that should be generated in the two motors. The command value is divided into individual command values using a changeable distribution ratio set for each of the motors, the individual command values respectively corresponding to the motors. The two controllers are configured to respectively supply the motors with current corresponding to the individual command values.

A vehicle steering device includes a turning shaft held in a housing so as to be movable in the axial direction, a ball screw transmitting drive force produced by an electric motor to the turning shaft, a bearing supporting a nut, which is a component of the ball screw, so as to be rotatable relative to the housing, and annular elastic members that support side faces of the bearing in the axial direction of the turning shaft across the entire circumference, and are formed of an elastic material. The elastic members include respective first elastic portions having a first load characteristic that gently increases the ratio of compression load per a unit compression amount deforming in the axial direction of the turning shaft, and respective second elastic portions having a second load characteristic that keenly increases the ratio in comparison with the first load characteristic.

A steering device of the present invention has a steered shaft rotation stopper (100) having a contact member (101) and a forcing member (102). The forcing member (102) forces at least either one of a steered shaft (6) or the contact member (101) in a direction in which the steered shaft (6) and the contact member (101) push against each other. In a state in which the contact member (101) contacts a contact portion (6D) of the steered shaft (6) , the contact member (101) stops a rotation of the steered shaft (6).

Provided is a power steering apparatus capable of improving accuracy of relative positions of a first circulation member and a second circulation member. A tube 23 includes a first first-tube-side abutment portion 40 and a second second-tube-side abutment portion 51, and a second first-tube-side abutment portion 41 and a first second-tube-side abutment portion 51, which are configured to restrict relative positions of a first tube 31 and a second tube 32 in a circumferential direction relative to a nut 8.