Abstract: First and second microcomputers are connected to a ground. A first reference voltage generation circuit is connected between a first power supply and the first microcomputer, and supplies a first reference voltage to the first microcomputer when voltage of the first power supply is higher than the first reference voltage. A first monitoring circuit is connected between a second power supply and the first microcomputer, and supplies the first microcomputer with a first monitoring voltage for monitoring the second power supply. The first microcomputer includes a part configured to perform an operation based on the supplied first reference voltage and the supplied first monitoring voltage, wherein the operation includes detecting abnormality in the voltages of the first and second power supplies, and determining which one of the voltage of the first power supply and the voltage of the second power supply is abnormal.

Abstract: An electrically driven power steering system is capable of reducing development of a noisy magneto-strictive sound. A voltage corresponding to each PWM pulse achieving time corresponding to a hysteresis is added to one of the voltage command values of a large voltage phase from among three phase first voltage command values. The added voltage is subtracted from one of the remaining voltage command values, which is a voltage small phase, to derive virtual voltage command values, and the virtual voltage command values are mutually compared to carry out a voltage magnitude phase determination for a three-phase brushless motor of the power steering system.

Abstract: A ball bearing for rotatably supporting a steering shaft, which is comprised of an input shaft and an output shaft connected to each other via a torsion bar is secured by a lock nut. The lock nut has an inside diameter Y1 greater than a maximum outside diameter X6 of the sensor body of a torque sensor mainly configured from a permanent magnet, first and second yoke members, and a magnetic sensor, which are disposed on the outer periphery of the steering shaft. With this configuration, the torque sensor and the lock nut radially overlap with each other, thus reducing the size of a device. Also, because of the lock nut being assembled so as to pass through the outer peripheral side of the torque sensor, component parts can be installed from one direction, thus improving the assembling workability of the device.

Abstract: A power steering system has: a steering shaft; a pinion shaft; a torque sensor; a rack housing communicating with inside of the sensor housing; a rack shaft provided in the rack housing; a motor housing communicating with inside of the rack housing; an electric motor provided in the motor housing; an ECU housing communicating with inside of the motor housing; a motor control unit housed in the ECU housing; and a respiration valve provided at any of the sensor housing, the rack housing and the motor housing and located at an upper side with respect to an upper end of the ECU housing in vehicle-mounted state. The respiration valve has function by which air passes through each house and between inside and outside of the ECU housing so as to absorb change of expansion/contraction of the air in the ECU housing while suppressing entry of water from the outside.

Abstract: A power steering device is provided with a device body and a hollow motor. The device body has a steering system in which a piston is disposed on an output shaft via a ball screw mechanism so that a steering (rotational) torque is transmitted from an input shaft to the output shaft and converted to rotation of a sector shaft by axial movement of the piston for steering of steerable wheels. The hollow motor is connected to the outer circumference of the input shaft and driven by energization control based on driving support information from a vehicle-mounted camera and the like. A key and a key groove are provided on the outer circumference of the input shaft and the inner circumference of a rotor of the hollow motor, respectively, so as to constitute a key connection between the input shaft and the hollow motor.

Abstract: A method of producing a rack is proposed, which comprises aligning a first bar piece, an intermediate piece and a second bar piece in order along a common axis; carrying out a first process in which the first and second bar pieces are stationarily held while showing a predetermined intersection angle between the first rack teeth on the first bar piece and the second rack teeth on the second bar piece; and carrying out a second process in which each of the first and second bar pieces and the intermediate piece are brought into contact with each other at mutually facing ends and subjected to a relative rotation therebetween for a friction welding thereby to join the first bar piece, the intermediate piece and the second bar piece together by the friction welding.

Abstract: A variable displacement vane pump includes first and second sealing grooves formed on an intake port side and separated away from each other in a circumferential direction; first and second sealing members provided in the first and second sealing grooves; a first fluid-pressure chamber formed on a side on which a volume thereof decreases when the cam ring moves to a side on which an eccentricity of the cam ring increases; and a second fluid-pressure chamber formed on a side on which a volume thereof increases when the cam ring moves to a side on which the eccentricity of the cam ring increases; and a control valve configured to control the pressure in the first or second fluid-pressure chamber.

Abstract: A variable displacement vane pump includes a pump housing, a drive shaft supported in the pump housing, a rotor rotated by the drive shaft, a plurality of vanes mounted to the rotor, a cam ring disposed movably around the pump element and a pressure plate arranged facing the rotor and the cam ring. The pressure plate has formed therein a discharge hole and a drive shaft insertion hole. The pump housing has formed therein a suction hole, a high-pressure chamber and a low-pressure chamber. The variable displacement vane pump further includes a first seal member disposed on a pressure receiving surface of the pressure plate so as to separate the drive shaft insertion hole from the high-pressure chamber and a second seal member disposed on the pressure receiving surface of the pressure plate so as to separate the low-pressure chamber from the high-pressure chamber and the drive shaft insertion hole.

Abstract: Provided are both a grease composition for an electric power steering device and an electric power steering device. The grease composition can keep a sufficiently low coefficient of friction in a sliding area between a steel and a resin over a long period, is less susceptible to being removed from the sliding area, does not cause break down of an oil film, and thus can minimize the occurrence of stick-slips. A grease composition for an electric power steering device, containing a synthetic hydrocarbon oil which exhibits a density of 0.75 to 0.95 g/cm3 at 15° C., a saturated aliphatic amide compound, boron nitride, a glycerin fatty acid partial ester, and a metal soap-based thickener; and an electric power steering device using the grease composition.

Abstract: A variable displacement vane pump and a power steering system are to be provided which can secure a discharge flow rate when a steering wheel is turned while restricting the discharge flow rate when the steering wheel is not turned. In a variable displacement vane pump and a power steering system, a bypass line is formed which causes a hydraulic fluid in a high pressure chamber of a control valve which controls an eccentricity of a cam ring to flow directly to a low pressure chamber side of the control valve when a steering wheel is turned.

Abstract: Disclosed is a torque sensor unit including a magnetic member fixed to a first output shaft member, a pair of first and second yoke members fixed to an input shaft member and surrounding an outer circumferential side of the magnetic member and a magnetic sensor adapted to detect a magnetic flux passing through between the yoke members. The magnetic member is provided with a sleeve and a permanent magnet. The sleeve is formed of a metal material in a substantially cylindrical shape and has a plurality of radially extending support portions and a plurality of axially extending engagement protrusions between the support portions. The permanent magnet is formed into an annular shape and has a plurality of axially extending engagement grooves cut in an inner circumferential surface thereof. The permanent magnet and the sleeve are coupled via a resin-based filling material.

Abstract: A steering angle sensor 17 is provided which can minimize a detection error even when a steering shaft 6 is inclined. In an annular clearance t1 defined between the steering shaft 6 and an inner cylindrical wall of a first gear 24, there is compressed an elastic O-ring 23. Due to provision of the elastic O-ring 23, inclination of the steering shaft 6, which tends to occur during handling of a steering wheel 1, is suitably absorbed by the elastic O-ring 23, and thus, generation of detection error caused by inclination of the first gear 24, which would follow the inclination of the steering shaft 6, is suppressed or at least minimized.

Abstract: An apparatus for power steering of a vehicle, comprises: a worm gear arrangement including a worm shaft and a worm wheel engaged with the worm shaft; a bearing to support the worm shaft rotatably; a gear housing structure enclosing the worm gear arrangement, and defining a holder receiving portion; and a holder member arranged to hold the bearing, and fit movably radially in the holder receiving portion. A biasing mechanism urges the holder member or the bearing in a nearing direction toward the worm wheel. A buffer member is arranged to be compressed by the holder member when the holder member is moved in the nearing direction to buffer collision of the holder member in the holder receiving portion. The buffer member is set to have an elastic force smaller than the biasing elastic force of the biasing mechanism.

Abstract: A variable displacement pump includes: a discharge opening formed at a position to confront a discharge region; a back pressure introduction groove formed on the suction region side; and a discharge side thin wall portion which is formed in the second housing, which has a recessed shape opened to the outside, which is disposed on the discharge region side, which is overlapped with the rotor in the radial direction, and which includes a smallest thickness portion having a smallest wall thickness of thicknesses each of which is an axial length between a bottom surface of the recessed shape and an axially inner side surface of the second housing, the smallest wall thickness being a smallest wall thickness of axial thicknesses of the second housing.

Abstract: In a power steering device employing both a worm speed reducer and a backlash adjuster for a worm gear of the speed reducer, the backlash adjuster has a slider configured to be movable in a longitudinal direction of a worm shaft, and a biasing member configured to bias the slider toward one side of the longitudinal direction of the worm shaft. Also provided is a guide member configured to bias the worm shaft in a direction for meshing with a worm wheel by a movement of the worm shaft in the meshing direction that the worm shaft approaches a rotation center of the worm wheel with a movement of the slider toward the one side of the longitudinal direction, and also configured to restrict a movement of the worm shaft in a direction opposite to the meshing direction of the worm shaft.

Abstract: Torque sensor detects torque of steering shaft formed by first and second shafts which are connected through torsion bar. Torque sensor has: a magnetic member provided at the first shaft and having magnetic poles alternately arranged in circumferential direction concentrically with rotation axis; a first yoke member provided at the second shaft and having (a) first nail portions arranged concentrically with the rotation axis and facing the magnetic member in radial direction and (b) a first ring portion; a second yoke member provided at the second shaft and having (c) second nail portions arranged concentrically with the rotation axis so that the first and second nail portions are alternately arranged in the circumferential direction and the second nail portions face the magnetic member in the radial direction and (d) a second ring portion arranged to be separated from and face the first ring portion; and a magnetic sensor.

Abstract: A power steering apparatus has a first characteristic which is a characteristic of a command signal with respect to steering torque and a second characteristic which is a characteristic different from the first characteristic. When switching is to be made to a characteristic selected from between the first and second characteristics, an interpolation characteristic intermediate between the first and second characteristics is calculated so that the characteristic used before switching of the characteristics gradually approaches the characteristic to be used after the switching, and a characteristic switching time for switching between the first and second characteristics is variably controlled in accordance with the steering torque.

Abstract: A variable displacement vane pump is provided. This pump includes a pump housing including, a driving shaft, a rotor, a plurality of vanes, a cam support surface, a cam ring, an intake port formed at the pump housing, a discharge port formed at the pump housing, and a cam ring control mechanism disposed at the pump housing and configured to control an eccentric amount of the cam ring with respect to the rotor. The cam support surface is formed in such a manner that a shortest distance between the cam support surface and a reference line decreases from a second confining region side toward a first confining region side, and the cam ring is formed in such a manner that a cam profile radius change rate decreases first and then increases again on the second confining region side when eccentric amount of the cam ring is maximized.

Abstract: A nut is formed by a die forging process in which a die used for the die forging process is released in a direction along the direction of the axis of rotation of the nut.

Abstract: In a stroke-limiter equipped integral power steering apparatus, a valve body of a spring-loaded-plunger-equipped limiter valve is configured to enable a position of the valve body relative to a housing to be adjusted in a longitudinal direction of the valve body via an intermediate sleeve.