A steer-by-wire steering system for a vehicle, including: an operating member operable by a driver; a dual-system steering device including two systems each of which includes an electric motor as a drive source, the steering device being configured to steer a wheel; and a controller configured to control a current to be supplied to each of the electric motors of the respective two systems so as to cause the steering device to steer the wheel in accordance with an operation of the operating member, wherein the controller is configured to prohibit the current greater than an upper limit value from being supplied to the electric motors of the respective two systems, and wherein, when the wheel is steered only by only one of the two systems, the controller raises the upper limit value of the current to be supplied to the electric motor of the one of the two systems.

A steer-by-wire steering system for a vehicle, including: an operating member operable by a driver; a dual-system steering device including two systems each of which includes an electric motor as a drive source, the steering device being configured to steer a wheel; and a controller configured to control a current to be supplied to each of the electric motors of the respective two systems so as to cause the steering device to steer the wheel in accordance with an operation of the operating member, wherein the controller is configured to prohibit the current greater than an upper limit value from being supplied to the electric motors of the respective two systems, and wherein, when the wheel is steered only by only one of the two systems, the controller raises the upper limit value of the current to be supplied to the electric motor of the one of the two systems.

A steer-by-wire steering system, including a steering device including a dual-system steering motor including a main system and a sub system, wherein a power supply to the main system is conducted selectively by a main power source and a backup power source, and a power supply to the sub system is conducted by only the main power source, wherein, in a normal power-supply situation in which the power supply to the main system and to the sub system is conducted by the main power source, a controller controls the sub system to operate in accordance with the main system, and wherein, in a backup power-supply situation in which the power supply to the main system is conducted by the backup power source, the controller controls the main system not to operate or to operate while limiting the power supply to the main system and controls the sub system independently.

A method for diagnosing whether or not a judder detection module mounted on a vehicle is operating normally includes receiving a diagnosis request requesting that the judder detection module of the vehicle be diagnosed; preparing for an execution environment for diagnosis of the judder detection module; activating the judder detection module; forcibly generating judder in the vehicle; and determining whether or not the judder detection module operates.

An electric power steering device includes a motor, a motor controller, first and second power source circuits, a power source switching circuit, and a voltage detector. The power source switching circuit is configured to switch between a first state in which the motor controller receives electric power from the first power source circuit but is cut off from the second power source circuit, and a second state in which the motor controller receives electric power from the second power source circuit but is cut off from the first power source circuit. The voltage detector is configured to detect the voltage of the first power source circuit. The power source switching circuit is configured to select the second state in a case where the voltage of the first power source circuit is less than or equal to a predetermined value, and select the first state in cases other than the case.

A steering device detecting airtightness of a road wheel actuator is proposed. The road wheel actuator includes a body unit, a motor unit connected to the body unit, and a controller connected to the motor unit. The controller checks an airtight state of a housing and bellows surrounding the body unit, the motor unit, and the controller.

A rotary electric machine control device for controlling a rotary electric machine having multiple winding sets includes multiple inverter circuits, multiple power supply relays, and multiple controllers provided for respective systems. Each of the controllers is configured to monitor an abnormality of a subject system and an abnormality of a different system and is configured to turn off a power supply relay in the subject system when an abnormality requiring a power supply stop occurs in the subject system. Each of the controllers is further configured to acquire power supply relay information related to a state of the power supply relay of the different system through a signal line, and is configured to monitor the abnormality of the different system based on the power supply relay information.

To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

A multi-piece gearwheel comprising an inner core section and an external toothed ring with external teething is presented. The core section has intermeshing teeth extending radially outwards, which have an undercut in cross-section in the radial direction. The toothed ring has recesses that originate from an inner side of the tooth ring and extend radially outwards, wherein the recesses are at least partially complementary to the intermeshing teeth, and wherein the intermeshing teeth are received in the recesses. Furthermore, a gearbox for an electromechanically-assisted steering system is described.