Provided is a power steering apparatus capable of reducing a maximumly generated stress on an output pulley. An output pulley of a power steering apparatus includes a fastening target portion around a screw insertion hole of a hub portion. When a boundary portion between the hub portion and a winding and hanging portion is defined to be a portion where a minor angle, among relative angles formed between a tangential line of an inner surface of the output pulley and a rotational axis of a nut in an axial cross section of the output pulley that passes through the rotational axis of the nut, gradually reduces from a nut-rotational-axis side toward a radially outer side to then reach 45 degrees, the fastening target portion is a region that is located on an inner side in a radial direction with respect to the boundary portion and overlaps a head portion of a screw in a radial direction of the screw.

A power conversion device includes a first inverter and a control circuit that controls an on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings, where n is an integer of three or more. The control circuit generates a control signal to turn off all of n low-side switches and n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches and measures the n-phase voltages that change depending on patterns of on failures of the switches, and executes a first failure diagnosis to diagnose the on failures of the n low-side switches and the n high-side switches based on the measured n-phase voltages by referring to a table associating the patterns of the on failures of the switches with n-phase voltage levels.

A motor control device is provided with a plurality of power converters and a plurality of microcomputers, and controls driving of a motor that has a plurality of sets of windings. The microcomputers perform initial check of components in respective circuits after activation. The microcomputers prohibit driving of the motor by a circuit determined to be abnormal during the initial inspection. When two or more circuits are determined to be normal in the initial check, the microcomputers start driving of the motor by synchronizing the timing between the two or more circuits determined to be normal. When only one circuit is determined to be normal in the initial check, the microcomputers start driving of the motor by the one circuit determined to be normal.

A control apparatus and method of a motor-driven power steering system are provided. The apparatus and method are capable of suppressing catch-up that occurs at a high steering speed even without using an expensive motor, thereby contributing to improving commercial value and reducing the manufacturing cost of a vehicle. The method includes determining a target steering speed using driver-steering input information and vehicle state information and determining the target steering speed corresponds to a condition for avoiding catch-up using the determined target steering speed. A current compensation value is then determined for reducing catch-up using the target steering speed in response to determining that is the target steering speed corresponds a condition for avoiding catch-up and motor current is compensated with the current compensation value.

A combined motor and gearbox assembly for an electric power steering system comprising an electric motor, a gearbox which includes a gearset that is connected on an input part to a rotor of the motor and in use is connected on an output part at least indirectly to a steering column shaft to transfer torque from the motor rotor to the steering column shaft, a motor drive circuit, a gearbox housing which in use accommodates the gearset of the gearbox, the electric motor including a motor housing, and a baseplate which connects an end face of the gearbox housing to an end face of the gearbox housing and which supports the drive circuit. At least one bolt having a stem passes through a central hole in a tubular rivet that secures the motor housing to the baseplate, the bolt securing the baseplate to the gearbox housing.

Heat radiation base body 23 that is adjacent to electric motor unit EM and extends in direction of rotation shaft 50 of electric motor is provided close to rotation shaft 50 of electric motor. Board 24 of one electronic control unit of redundant system is fixed to heat radiation base body along direction in which heat radiation base body 23 extends with thermal conduction to heat radiation base body 23 allowed. Board 26 of the other electronic control unit of redundant system is fixed to heat radiation base body so as to face to board 24 of one electronic control unit of redundant system, with thermal conduction to heat radiation base body 23 allowed. Size reduction of electric drive device in radial direction can be achieved. Since heat radiates to housing of electric motor unit through heat radiation base body, heat from board can radiate efficiently to the outside.

A power-steering system for a motor vehicle includes a steering wheel and an assistance motor controlled by a closed-loop regulation system, the regulation system determining a motor torque of the assistance motor as a function of a measured steering-wheel torque, using at least one “setpoint monitoring” arm calculating a component of the motor torque, referred to as “variant motor torque”, by subtracting a set steering-wheel torque from the RFe corresponding to the sum of the measured steering-wheel torque and the motor torque, wherein the variant motor torque is multiplied by a gain determined by a three-dimensional map as a function of a vehicle speed and the measured steering-wheel torque.

A hoisting machinery comprises a steering wheel and wheels, wherein the active steering system comprises an active steering device, a hydraulic power steering gear and a hydraulic power steering system, the active steering device is arranged between the steering wheel and a pitman arm of the hoisting machinery, so as to adjust a steering ratio of the steering wheel to the pitman arm according to a driving cycle of the hoisting machinery, and the hydraulic power steering gear is arranged between the steering wheel and the pitman arm, so as to control the hydraulic power steering system to drive steering of the wheels. In the active steering system of the present invention, a hydraulic power steering system is adopted to drive steering of wheels, which can improve capability of overcoming steering resistance and can be applicable to multiple chassis of cranes, thereby enlarging application ranges of the active steering system.

A hoisting machinery comprises a steering wheel and wheels, wherein the active steering system comprises an active steering device, a hydraulic power steering gear and a hydraulic power steering system, the active steering device is arranged between the steering wheel and a pitman arm of the hoisting machinery, so as to adjust a steering ratio of the steering wheel to the pitman arm according to a driving cycle of the hoisting machinery, and the hydraulic power steering gear is arranged between the steering wheel and the pitman arm, so as to control the hydraulic power steering system to drive steering of the wheels. In the active steering system of the present invention, a hydraulic power steering system is adopted to drive steering of wheels, which can improve capability of overcoming steering resistance and can be applicable to multiple chassis of cranes, thereby enlarging application ranges of the active steering system.

An electric power steering device includes: —a steering column provided with: a base; an upper segment connected in a tiltable manner to the base, a steering axis comprising a lower axis rotatably contained inside the base; —a hydrostatic steering assembly; —an electrically assisted steering apparatus axially interposed between the steering column and the hydrostatic steering assembly and provided with: a support frame comprising a tubular central body; a shaft whose upper end axially projects outside an upper end of the central body and is connected to the lower end of the lower axis and whose lower end is connected to the hydrostatic steering assembly; and an electric motor positioned inside the central body of the support frame; in which the upper end of the central body is directly fixed to the base and in contact therewith.