An object of the present invention is to provide a rotational angle detection apparatus and a power steering apparatus capable of detecting a rotational angle of a rotational shaft eve when a failure has occurred in a magnetic detection portion. One aspect of the present invention is a rotational angle detection apparatus including a first magnetic detection portion provided on a rotational axis and configured to detect a change in a magnitude or a direction of a magnetic field, and a second magnetic detection portion provided on the rotational axis and disposed at a position offset from the first magnetic detection portion in a direction along the rotational axis. The second magnetic detection portion is configured to detect the change in the magnitude or the direction of the magnetic field. The rotational angle detection apparatus further includes a magnet provided on an outer side in a radial direction of the rotational axis with respect to the first magnetic detection portion and the second magnetic detection portion and disposed in such a manner that an N-pole and an S-pole face each other around the rotational axis. The magnet is provided rotatably relative to the first magnetic detection portion and the second magnetic detection portion. The rotational angle detection apparatus is configured to detect a rotational angle of the magnet relative to the first magnetic detection portion and the second magnetic detection portion based on signals output from the first magnetic detection portion and the second magnetic detection portion.

The invention relates to a gear reducer (1) for an assisted-steering module, including a casing (3), a worm (4) which meshes with a worm wheel (6), and a spring (10) for taking up gear play, which presses said worm (4) radially against the worm wheel (6), the wall of the casing (3) being bored, away from of the axis (XX′) of the worm, with an opening (14) sealed by a plug (15), the spring (10) for taking up gear play including at least one retaining lug (17, 18) which projects radially to the axis (XX′) of the worm (4), and the hub (20) of the plug (15) having a guiding wall (21) that is substantially transverse to the axis (XX′) of the worm (4), which is designed to be placed axially opposite said at least one retaining lug (17, 18), in order to prevent the axial movement of the spring (10) beyond a predetermined functional travel.

An electric power steering system includes a rack housing configured to accommodate a rack shaft, a pinion shaft meshed with the rack shaft, a speed-reducer including a worm wheel connected to a portion of the second pinion shaft protruding from the rack housing, a speed-reducer housing configured to accommodate the speed-reducer, and a seal member having an annular shape. The seal member is disposed closer to the second pinion gear than the worm wheel is, in the speed-reducer housing. The sear member seals a clearance between the second pinion shaft and the speed-reducer housing.

Disclosed is a power steering apparatus including: a rack shaft that includes a rack, and moves front wheels; a steering wheel-side pinion shaft that includes a pinion meshing with steering wheel-side rack teeth of the rack shaft, and is rotated along with the steering of a steering wheel; an assistance unit-side pinion shaft that includes a pinion meshing with an assistance unit-side rack of the rack shaft, and is driven by an electric motor to rotate so as to assist the rotation of the steering wheel-side pinion shaft; and a steering angle sensor that is provided on the assistance unit-side pinion shaft, and detects a rotational angle of the assistance unit-side pinion shaft.

An electric power steering device includes a composite metal member. The composite metal member is formed by laminating a plurality of metal plates that have different thermal expansion coefficients. The composite metal member is capable of causing a worm shaft to oscillate and be displaced away from a worm wheel on the basis of deformation of the composite metal member if the temperature thereof has become higher than a reference temperature. The composite metal member is also capable of causing the worm shaft to oscillate and be displaced towards the worm wheel on the basis of deformation of the composite metal member if the temperature thereof has become lower than the reference temperature.

A steering system for a vehicle includes a drive motor having a motor shaft. The steering system also includes a first gear reduction stage for receiving a first rotational input from the motor shaft and providing a first rotational output. The steering system further includes a second gear reduction stage for receiving the first rotational output from the first gear reduction stage and providing a second rotational output. The second gear reduction stage may include at least one of a strain wave gearing, a worm drive, and a planetary gearing. The steering system includes an output shaft for receiving the second rotational output from the second gear reduction stage.

An embodiment of a control system includes a current command module configured to receive a torque command and output a current command for controlling a direct current (DC) motor, and a current capability limiting module configured to receive the current command and a current limit indicating a maximum motor current, limit the current command based on the current limit, and actively further limit the current command based on a capability limit value.

A steering device includes: a housing; and a spring configured to urge the retainer toward the rack bar in the second axis direction, and the rack bar, the retainer, the spring, and the spring holding member being disposed in this order in the second axis direction; the retainer chamfering portion provided on the retainer second end portion near the spring holding member, on a retainer second end portion outer circumference portion, and the retainer chamfering portion formed at a portion which is nearest the spring holding member abutment surface in the retainer second end portion outer circumference portion in a section that passes through the second axis, and that is perpendicular to the first axis, when the retainer main body portion is inclined with respect to the second axis.

An electric power steering apparatus arranged in the vicinity of a heat source mounted on a vehicle includes: a rack shaft that turns a road wheel; an output shaft provided with a pinion gear engaged with a rack gear of the rack shaft; a worm wheel provided on the output shaft; a worm shaft engaged with the worm wheel; an electric motor that drives the worm shaft; and a controller that controls driving of the electric motor, and wherein at least a part of the controller is arranged on the opposite side of the heat source such that a rack housing is sandwiched between at least a part of the controller and the heat source, the rack housing accommodating the rack shaft.

The embodiment relates to a steering control device and method and includes a steering control device for controlling a first motor generating steering feedback torque in response to rotation of a steering wheel and a second motor generating rack driving torque for moving a rack, comprising a calculation unit calculating allowed rack speed information regarding a rack speed allowed when driving the rack using the second motor, based on rack force information and preset second motor performance information and calculating catch-up prevention torque information for preventing catch-up in the steering wheel, based on the allowed rack speed information and command rack speed information generated to drive the rack at a speed in response to rotation of the steering wheel and a controller performing catch-up prevention control on the first motor based on the catch-up prevention torque information.