A steering apparatus includes a turning shaft movable in a vehicle widthwise direction, a pinion shaft meshed with the turning shaft and a first housing that retains therein the turning shaft and the pinion shaft. An inner circumferential surface of the first housing facing with the turning shaft is provided with an inclined portion that continuously changes an internal diameter. When a portion where a tooth of the turning shaft and a tooth of the pinion shaft are meshed with each other is defined as a meshed portion, the inclined portion is formed below at least the meshed portion.

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.

An electronic control unit is provided for an electric power steering system. The electric power steering system includes a housing and an electric motor. The electronic control unit is arranged inside the housing and is electrically connected to the electric motor. The electronic control unit includes a first power board having a first electric motor connector for electric connection with the electric motor, and a second power board having a second electric motor connector for electric connection with the electric motor. A connector plate of the electronic control unit is electrically connected by at least one plug connector to the first power board via at least one first power connector, and to the second power board via at least one second power connector. The at least one first power connector is shorter than the at least one second power connector. An electric power steering system is also provided.

An electronic control unit is provided for an electric power steering system. The electric power steering system includes a housing and an electric motor, and the electronic control unit is arranged inside the housing with an electrical connection to the electric motor. The electronic control unit includes at least one power board and a heat sink. The at least one power board is attached to the heat sink. A heat sink edge of the heat sink includes a groove, into which at least a portion of the housing is crimped to secure the heat sink with the housing. The electric power steering system is also provided.

An electronic control unit is provided for an electric power steering system. The electric power steering system includes a housing and an electric motor. The electronic control unit is arranged inside the housing, and is electrically connected to the electric motor. The electronic control unit includes a first power board having a first electric motor connector for electric connection with the electric motor, and a second power board having a second electric motor connector for electric connection with the electric motor. The electronic control unit also includes a logic board logically connected with the first power board and the second power board. An electric power steering system is also provided.

Provided is a feature capable of improving steering sensation in an electric power steering control device. This electric power steering control device is provided with: a basic control amount calculation unit that calculates a basic control amount corresponding to driver's steering; a friction force calculation unit that calculates, by using a friction model, a friction force corresponding to at least one of a yaw rate and lateral acceleration, and calculates a friction-caused control amount resulting from the calculated friction force; and a control amount calculation unit that calculates a steering control amount in accordance with the basic control amount and the friction-caused control amount.

A first offset correction and a second offset correction are switched between in a cycle T.sub.c shorter than an electrical angle cycle of an alternating current rotating machine, the first offset correction is such that a first shift amount is fixed in such a way as to obtain an applied voltage such that at least n-2 phases among phase currents of the alternating current rotating machine can be detected, and the applied voltage is calculated by the first shift amount being subtracted equally from all voltage commands, and the second offset correction is such that a second shift amount is fixed in such a way that a sign of an average value in an electrical angle cycle is reversed with respect to that of an average value in an electrical angle cycle of the first shift amount, and the applied voltage is calculated by the second shift amount being subtracted equally from all the voltage commands.

The disclosure relates to a method for operating a steer-by-wire steering system which includes at least one steering input element, at least one steering actuating element operatively connected to the steering input element, at least one first end stop for mechanically limiting a movement of the steering actuating element in a first direction of movement and at least one second end stop for mechanically limiting a movement of the steering actuating element in a second direction of movement, wherein a steering ratio between the steering input element and the steering actuating element is adapted such that a maximum deflection of the steering input element in a first steering direction, in which the steering actuating element reaches the first end stop, and a maximum deflection of the steering input element in a second steering direction, in which the steering actuating element reaches the second end stop, are at least substantially identical.

An electric driving device and an electric power steering device. An electric driving device includes a motor and an electronic control unit that controls rotation of the motor. The electronic control unit includes a first circuit board, a second circuit board, a second housing, a lid, and an inter-board connector. The second circuit board includes a control circuit that controls an electric current supplied to a transistor of the first circuit board. The second housing accommodates the second circuit board and has a first through hole passing therethrough in the axial direction. The lid covers the second housing. The inter-board connector connects the second circuit board disposed on the anti-load side of the second housing to the first circuit board disposed on the load side of the second housing. The inter-board connector is disposed in the first through hole.

A terminal position learning unit includes a first storage unit configured to store a steered position positioned farthest from a neutral position of a turning mechanism within a range of a steered position detected by a position detection unit when rotational force applied to the turning mechanism is less than or equal to a first predetermined value, a second storage unit configured to store a steered position positioned farthest from the neutral position within a range of a position to which a steered position detected by the position detection unit is shifted in a direction toward the neutral position by a second predetermined value, and a third storage unit configured to store, as a terminal position stored by the terminal position learning unit, one of the steered positions stored in the first storage unit and the second storage unit positioned farther from the neutral position than the other.