Patent application number | Description | Published |
20080216589 | Magnetostrictive torque sensor and electric power steering apparatus - A magnetostrictive torque sensor includes a rotating shaft rotatably supported; magnetostrictive materials provided on a surface of the rotating shaft, magnetic permeability of which changes according to the magnitude of rotary torque acting on the rotating shaft; and at least two detection coils provided to the rotating shaft, which detect change in the magnetic permeability of the magnetostrictive materials to output in the form of electrical change. Section secondary moments of the rotating shaft at its parts on which the detection coils are respectively placed are different from each other. | 09-11-2008 |
20080245161 | Magnetostrictive torque sensor and method for manufacturing same - A magnetostrictive torque sensor for detecting a torque comprises an operating shaft, a first hollow shaft, a second hollow shaft, a first magnetostrictive film, and a second magnetostrictive film. Torque acts on the operating shaft from the outside. The first and second hollow shafts are fitted and fixed separately on the operating shaft. The first magnetostrictive film is formed on an external peripheral surface of the first hollow shaft while the second magnetostrictive film is formed on an external peripheral surface of the second hollow shaft. | 10-09-2008 |
20080295613 | Magnetostrictive torque sensor - A magnetostrictive torque sensor for detecting a torque includes an operating shaft, magnetically insulating layers, and magnetostrictive films. The operating shaft is adapted to be applied with an external torque. The magnetically insulating layers are formed of a nonmagnetic material and provided on an outer peripheral surface of the operating shaft. The magnetostrictive films are provided on outer peripheral surfaces of the magnetically insulating layers. | 12-04-2008 |
20090107271 | Rack-and-pinion steering apparatus - A rack-and-pinion steering apparatus in which a steering gear box for transmitting an operation of a steering wheel to road wheels includes a pinion operatively connected to the steering wheel, a rack bar which has a rack meshing with the pinion, and which is operatively connected to the road wheels, a housing slidably supporting the rack bar, a cylindrical rack guide slidably fitted into a guide hole formed in the housing, and a spring member causing the rack guide to abut on a rear part of the rack bar opposite to the rack by biasing the rack guide. A reaction force, which the rack guide receives from the rack bar, acts on the rack guide in such a way as to cause a rotational moment of the rack guide about an axis different from an axis of the rack guide. | 04-30-2009 |
20090107756 | Motor rotation angle detection device - A motor rotation angle detection device, comprising a resolver which detects a rotation angle of a motor generating an assist torque for steering road wheels. The resolver includes an annular rotor disposed inside an annular stator with an air gap interposed in between an outer circumferential surface of the rotor and an inner circumferential surface of the stator, so that the stator and the rotor are rotatable relative to each other, wherein a rotor supporting member is connected to a rotary shaft of the motor, and the rotor extends out from an axial end portion of the rotor supporting member so as to surround an outer periphery of the rotary shaft. With the such a motor rotation angle detection device, it is possible to stabilize the magnetic permeability of the rotor, and accordingly to increase an accuracy with which the rotation angle of the motor is detected. | 04-30-2009 |
20090114470 | Electric power steering device - An electric power steering device is configured to transmit an auxiliary torque to a steering unit of front wheels, and includes: an operator; an electric motor configured to generate the auxiliary torque in accordance with at least a steering torque generated by input from the operator; the steering unit of front wheels which includes a pinion shaft; and a rotation terminating mechanism which provides a motion terminating end of the operator, the rotation terminating mechanism being disposed between the operator and the pinion shaft. | 05-07-2009 |
20090218162 | Magnetostrictive torque sensor device, manufacturing method thereof, and vehicle steering apparatus - A magnetostrictive torque sensor device which detects a torque applied to a rotary shaft is provided. The magnetostrictive torque sensor device includes a magnetostrictive portion provided on a surface of the rotary shaft, a coil and a cylindrical back-yoke disposed in outer periphery of the coil. The coil includes a bobbin arranged in outer periphery of the magnetostrictive portion, and a wire wound around the bobbin. A slit is provided on the back-yoke. | 09-03-2009 |
20090250288 | Steering apparatus - An electric power steering apparatus | 10-08-2009 |
20090288288 | TORQUE SENSOR AND METHOD OF MANUFACTURING THE SAME - The torque sensor includes a plurality of coil units having a substantially cylindrical shape, the coil units including a plurality of detection coils arranged to face a magnetic characteristic change portion formed on a rotary shaft. The coil units include a first coil unit and a second coil unit, and the first coil unit and the second coil unit are disposed in the axial direction of the shaft. The first coil unit and the second coil unit are fixed in an integrally molded resin. Thereby, there is provided a torque sensor having a high productivity and an easy configuration and a method of manufacturing the torque sensor. | 11-26-2009 |
20100121531 | CONTROLLER OF ELECTRIC POWER-ASSIST STEERING SYSTEM - The present invention discloses a controller of an electric power-assist steering system including a torque detector for detecting a torque applied with a steering wheel that steers a steering system; a steering status determining section for determining a steering status of either “turn” or “return” of a steering wheel; and a motor controlling unit for driving a motor n accordance with a target current value calculated based on at least a torque value from the torque detector and the steering status of either “turn” or “return” of the steering wheel from the steering status determining section, wherein the motor controlling unit sets a target current value right after a time when the steering status is switched between “turn” and “return” to be substantially equal to an actual current value right before a time when the steering status is switched between “turn” and “return”. | 05-13-2010 |
20100170742 | MAGNETOSTRICTIVE TORQUE SENSOR, AND PRODUCTION METHOD AND EVALUATION METHOD FOR SAME - A method produces a magnetostrictive torque sensor which detects a steering torque applied to a steering shaft by electrically detecting distortion of magnetostrictive films provided on a surface of the steering shaft. A plating step forms the magnetostrictive film on the surface of the steering shaft, and a heat treatment step heat treats the magnetostrictive film on the steering shaft. During the heat treatment step, hydrogen in the magnetostrictive film is decreased so that a hydrogen desorbing peak around 120° C. disappears when the magnetostrictive film is heated after the heat treatment step. | 07-08-2010 |
20110231066 | ELECTRIC POWER STEERING APPARATUS AND ELECTRIC MOTOR DRIVING CONTROLLER USED FOR THE APPARATUS - A q-axis target current setting unit generates a q-axis current command value based on a steering input signal from a steering torque sensor and a vehicle speed signal from a vehicle speed sensor. An electric motor generates a predetermined torque based on the q-axis current command value and a q-axis current (a torque current) to which a fed back q-axis real current is added. On the other hand, a d-axis correction current setting unit sets a field weakening current (a d-axis current) in response to a voltage saturation (duty ratio=driving voltage of electric motor/power supply voltage) output from a voltage saturation calculating unit. For this reason, when the voltage saturation becomes high, distortion (harmonics component) in current can be decreased by decreasing the voltage saturation while keeping the torque constant using a predetermined torque current, and a torque ripple can be suppressed. | 09-22-2011 |
20110240400 | ELECTRIC POWER STEERING SYSTEM - An electric power steering system includes a steering wheel, a rack-and-pinion type steering gear box connected to the steering wheel, a steering torque sensor, a pinion shaft, and a steering actuator mounted on the pinion shaft to assist a steering operation conducted by a driver. An overload preventing control is conducted so that a sum of a torque conversion value of an assist current and a steering torque detected by the steering torque sensor equal a predetermined threshold value. When the steering gear box has reached a stroke end, and the assist current or the steering torque is smaller than a predetermined threshold value, the overload preventing control is conducted using a threshold value that is less than the predetermined threshold value. | 10-06-2011 |
20110303480 | ELECTRIC POWER STEERING APPARATUS - In an electric power steering apparatus, an elastic member, disposed between the steering shaft and the housing, configured to be elastically deformed in accordance with rotation or displacement in a vehicle width direction, of the steering shaft. At least two bearings, disposed with a gap in an axial direction of the steering shaft, are configured to support the steering shaft. The elastic member is disposed between the bearings. A supporting member may be disposed between the steering shaft and the elastic member and configured to be displaced by a rotation of a predetermined angle or predetermined distance in accordance with the rotation or a displacement, in the width direction of the vehicle, of the steering shaft with slidable support for the steering shaft. The elastic member is fixed to the supporting member and abuts the housing. | 12-15-2011 |
20120216645 | WORM WHEEL - Provided is a worm wheel that allows the residual stress in the plastic gear forming member thereof to be reduced, and suited for compact design. The worm wheel comprises a metallic core member ( | 08-30-2012 |
20120242054 | SHOCK ABSORBING DEVICE FOR RACK AND PINION TYPE STEERING MECHANISM - A shock absorbing device for a rack and pinion type steering device includes a rack shaft, a rack housing, a stopper portion formed in an end part of the rack shaft, a stopper engaging portion provided on the rack housing to define a stroke end position for the rack shaft by engaging the stopper portion, a stepped portion formed on the rack shaft, a shoulder portion formed in an enlarged diameter portion of the rack housing, and a cylindrical elastic member fitted on the rack shaft such that the elastic member is pressed in the axial direction of the rack shaft by the stepped portion and the shoulder portion. The elastic member is formed with grooves on each of an outer circumferential surface and an inner circumferential surface thereof. Such shock absorbing device for a rack and pinion type steering device has a high shock absorbing capability. | 09-27-2012 |
20130133969 | MAGNETOSTRICTIVE TORQUE SENSOR, ELECTRICALLY ASSISTED BICYCLE AND ELECTRIC POWER STEERING APPARATUS CARRYING THE SENSOR - A magnetostrictive torque sensor includes a magnetostrictive portion formed on a rotational shaft, a bobbin surrounding an outer circumference of the magnetostrictive portion, and a coil wound on the bobbin for detecting a change in magnetic property of the magnetostrictive portion. The bobbin fits over the magnetostrictive portion in contact with the magnetostrictive portion in such a manner as to allow rotation of the magnetostrictive portion relative to the bobbin. The magnetostrictive torque sensor is carried on an electrically assisted bicycle or an electric power steering apparatus of a vehicle. | 05-30-2013 |
20130152703 | MAGNETOSTRICTIVE TORQUE SENSOR AND METHOD OF MANUFACTURING THE SAME - A magnetostrictive torque sensor includes a housing configured to house a magnetostrictive element provided on a rotary shaft, a single coil bobbin and detection coils wound on the coil bobbin. The housing includes a plastic housing body having a generally cylindrical shape and molded integrally with the coil bobbin having the detection coils wound thereon, a metal flange portion disposed on an axial end portion of the generally cylindrical plastic housing body, and a plastic fastener member firmly connecting the metal flange portion to the axial end portion of the plastic housing body. A method of manufacturing such torque sensor is also disclosed. | 06-20-2013 |