Methods and apparatus to determine rack force are disclosed. An example apparatus includes a rack to couple to a steering knuckle of a vehicle, a ball nut engaged with the rack, a first ring gear coupled to the ball nut, a first pinion fixed to a motor, the first pinion engaged with the first ring gear, the motor to rotate the ball nut to move the rack, a motor encoder to detect a rotation of the first pinion, a second ring gear coupled to the ball nut, and a sensor fixed to a second pinion, the second pinion engaged with the second ring gear, the second pinion to rotate as the second ring gear rotates, the sensor to detect a rotation of the second pinion, the rotation of the second pinion and the rotation of the first pinion corresponding to a force on the rack.

A steer-by-wire steering assembly comprises a housing and a motor assembly having at least one rotor and at least one stator having a first motor winding and a second motor winding, the at least one stator being mounted to the housing. A steering shaft comprises a threaded portion configured to engage with a screw actuator and to move longitudinally with respect to the housing when the first motor winding and/or the second motor winding is actuated. A rotational sensor is mounted on the housing adjacent to one or more rotatable components. The rotational sensor is configured to generate a signal in dependence on detecting rotational movement of the rotatable components. A linear displacement sensor is mounted to an end of the steering shaft. The linear displacement sensor is configured to generate a signal in dependence of detecting linear movement of the steering shaft.

A steering system for use in turning steerable vehicle wheels includes a gear in a housing and rotatable relative to the housing via an electric motor. A planetary gear stage is in the housing and has a sun gear, a planetary gear meshed with the sun gear, and a carrier connected to the planetary gear. Rotation of the gear urges the sun gear to rotate about an axis. Rotation of the sun gear urges the planetary gear to rotate relative to the housing and orbit the sun gear. The carrier is urged to rotate about the axis in response to the planetary gear rotating relative to the housing and orbiting the sun gear. A bearing has a first race on the gear and a second race on the carrier. The gear and the carrier are rotatably supported in the housing on one another via the bearing.

The present embodiments provide a steering apparatus for vehicle including a motor pulley coupled to the rotation shaft of the driving motor, a nut pulley coupled to the outer circumferential surface of the ball nut, a belt connecting the motor pulley and the nut pulley, a first groove provided on an outer peripheral surface of at least one of the motor pulley and the nut pulley, a second groove provided on an inner surface of the belt at a position opposite to the first groove, and a slip preventing member coupled to the first groove.

Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

A steering control apparatus is provided which allows mitigation of an adverse effect of a technique for fixing a regulation member to a vehicle body on a phenomenon resulting from execution of steering operation control on steered wheels. An axial-force acquisition processing circuit calculates a rack axial force based on currents iu, iv, and iw flowing through a steering operation motor. A correction processing circuit corrects a target steered angle based on the rack axial force to obtain a target steered angle. A steered angle control processing circuit calculates a torque command value as the amount of operation for adjusting a steered angle to the target steered angle through feedback control. An operation signal generation processing circuit controllably adjusts a torque of a steering operation motor to the torque command value.

Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

It is an object of the present invention to provide a rear wheel steering device of which the weight is not added to unsprung weight, and which can steer right and left rear wheels independently of each other. The rear wheel steering device includes a first rod connected to the left rear wheel, a first driving portion configured to axially move the first rod, a second rod connected to the right rear wheel, a second driving portion configured to axially move the second rod; and a single housing supporting the first rod, the first driving portion, the second rod, and the second driving portion.

A rear wheel steering apparatus for a vehicle includes: a housing connected via first and second connecting members to a suspension mechanism supporting rear wheels of a vehicle; an electric motor accommodated in the housing; a planetary gear mechanism having a sun gear connected to an output shaft of the electric motor, a ring gear non-rotatably supported inside the housing, a planetary gear meshing with the ring gear and the sun gear, and a carrier connected to the planetary gear, and reducing the output of the electric motor; and a linear motion mechanism having a nut member connected to the planetary gear mechanism and forming the carrier, and a rod screwed to the nut member and connected to the second connecting member, and converting the rotational motion of the nut member into the linear motion of the rod.

A steering apparatus includes a first CAN communication line provided between a steering input mechanism and a steering mechanism controller and configured to output a first steering operation amount signal output from a first steering operation amount signal output portion to the steering mechanism controller, and a communication line provided between the steering input mechanism and the steering mechanism controller and configured to output a second steering operation amount signal to the steering mechanism controller without intervention of a first microprocessor.