Abstract: A flat surface portion is formed on a nut so as to extend to a region where an output pulley attachment portion is formed in an axial direction, and extend substantially in parallel with a tangential direction of a rotational axis of the nut. A ball circulation groove one end side opening, and a ball circulation groove opposite end side opening are formed on the nut. The ball circulation groove one end side opening is in communication with one end of a ball circulation groove and is formed so as to be opened to the flat surface portion in the region where the output pulley attachment portion is formed. The ball circulation groove opposite end side opening is in communication with an opposite end of the ball circulation groove and is formed so as to be opened to the flat surface portion.

Abstract: In a power steering system, a torque sensor obtains first and second rotation angles, and a steering angle sensor obtains third and fourth rotation angles. A controller includes a first absolute rotation angle calculation section, a second absolute rotation angle calculation section, and an abnormality detection section. The first absolute rotation angle calculation section calculates a first absolute rotation angle as a first estimate of an absolute rotation angle of a steering wheel based on the first and third rotation angles. The second absolute rotation angle calculation section calculates a second absolute rotation angle as a second estimate of the absolute rotation angle of the steering wheel based on the third and fourth rotation angles. The abnormality detection section detects an abnormality by comparison between the first absolute rotation angle and the second absolute rotation angle.

Abstract: In a power steering system, at least one of phase open relays in which a contact weld (an abnormality) occurs is detected. That is to say, the power steering system comprises an abnormality monitor section (57) configured to output vector control command signals to supply only a d-axis current in a positive side direction toward the motor, with all of phase open relays (58v, 58w) in an interruption state, and to determine an abnormality in at least one of the phase open relays in a case where a current value is detected by a current detection circuit which detects a current flowing into an inverter. In a case of three phase open relays installed between respective three phases of motor windings, a potential difference is detected at a neutral position of a star connection to determine the abnormality of at least two of the phase open relays.

Abstract: In a power steering system and a control apparatus for the power steering system, an abnormality detection process section (27) installed in a second ECU, the second ECU, the second ECU having a multi-core microcomputer in which a plurality of processor cores are mounted within a single processor package, to detect an abnormality of a first angle calculation process section of a first ECU, the first ECU having a single core microcomputer in which a single processor core is mounted within another single processor package and the first angle calculation process section a first angle calculation process section (21) installed in the first ECU to calculate rotation angles of the input axle and output axle on a basis of sinusoidal wave signals and cosine wave signals derived from a steering angle sensor and a torque sensor.

Abstract: The present invention performs pulse shift control in such a manner that a difference between switching timings of PWM duty signals can reach or exceed a second predetermined value when the difference between the switching timings of the PWM duty signals of phases falls below the first predetermined value, and determines a correction amount for the phase by the pulse shift control in such a manner that a correction amount after switching becomes smaller than a correction amount before the switching of a phase on which the pulse shift control is performed in pulse shift phase switching control.

Abstract: A fixation member is circularly formed to surround a wheel turning shaft and includes an abutment surface in abutment with an end surface of a bearing on one axial side. The fixation member fixes the bearing to a housing by being fixed in the housing with the abutment surface in abutment with the end surface of the bearing. When being mounted, the fixation member is provided by being moved from an opposite axial end side to one axial end side of the nut. The abutment surface of the fixation member is formed on at least a radially inner side of the fixation member. The fixation member includes a cutout portion provided on the radially inner side of the fixation member and formed to prevent interference with a circulation member when the fixation member is inserted in the housing.

Abstract: A flat surface portion is formed on a nut so as to extend to a region where an output pulley attachment portion is formed in an axial direction, and extend substantially in parallel with a tangential direction of a rotational axis of the nut. A ball circulation groove one end side opening, and a ball circulation groove opposite end side opening are formed on the nut. The ball circulation groove one end side opening is in communication with one end of a ball circulation groove and is formed so as to be opened to the flat surface portion in the region where the output pulley attachment portion is formed. The ball circulation groove opposite end side opening is in communication with an opposite end of the ball circulation groove and is formed so as to be opened to the flat surface portion.

Abstract: A power steering apparatus including a power cylinder, first and second pumps, a control valve serving for selectively supplying a working fluid supplied from the first or second pump to one of a pair of pressure chambers of the power cylinder in accordance with a steering operation, first and second reservoir tanks, and a return passage changeover valve disposed between the control valve and the first and second pumps, the return passage changeover valve serving for communicating the first and second pumps with the control valve regardless of an axial position of a valve element and communicating one of the first and second reservoir tanks with the control valve in accordance with the axial position of the valve element to thereby carry out changeover between circulating fluid passages for circulating the working fluid to the first reservoir tank and the second reservoir tank.

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: 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: In an electrically driven power steering system having a blushless three phase motor, an abnormality of a control unit is detected on a basis of a direct current bus bar current of an inverter detected by a current sensor and an estimated primary current. The estimated primary current is calculated from, for example, the following equation, namely, Iu×Du+Iv×Dv+Iw×Dw)/100%, wherein Iu denotes a current of a U phase of the motor, Du denotes a PWM duty signal of the U phase, Iv denotes a current of a V phase of the motor, Dv denotes the PWM duty signal of the V phase of the motor, Iw denotes a current of a W phase of the motor, and Dw denotes the PWM duty signal of the W phase.

Abstract: A steering angle sensor for a vehicle including a steering angle sensor housing, a first gear, a rotation transmitting portion, a second gear meshing with the first gear, a third gear meshing with the first gear or the second gear, first and second magnetoresistance effect elements to detect first and second rotation angles as rotation angles of the second and third gears, respectively, and a biasing member disposed in the steering angle sensor housing to bias the first gear toward the second gear, wherein the first and rotation angles are combined to determine an absolute steering angle indicative of an amount of rotation of a steering wheel when the steering wheel is rotated from a neutral position in which a steerable road wheel is oriented to a straight ahead direction of the vehicle.

Abstract: An electric power steering device includes a rack bar; a pinion shaft meshing with the rack bar; a worm wheel provided on the pinion shaft; a worm shaft meshing with the worm wheel; an electric motor provided on the worm shaft; a first housing accommodating at least a part of the rack bar and the pinion shaft and includes a first bolt boss formed with a through-hole; a second housing; and a bolt. The second housing includes a worm-wheel accommodating portion accommodating the worm wheel, and a second bolt boss provided to have a shorter distance to the first housing than that of the worm-wheel accommodating portion, and formed with a female-threaded portion. The second bolt boss is opposed to the first bolt boss to cause the female-threaded portion to be continuous with the through-hole of the first bolt boss. The bolt fastens the first housing to 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: 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: In an electrically driven power steering system having a blushless three phase motor, an abnormality of a control unit is detected on a basis of a direct current bus bar current of an inverter detected by a current sensor and an estimated primary current. The estimated primary current is calculated from, for example, the following equation, namely, Iu×Du+Iv×Dv+Iw×Dw)/100%, wherein Iu denotes a current of a U phase of the motor, Du denotes a PWM duty signal of the U phase, Iv denotes a current of a V phase of the motor, Dv denotes the PWM duty signal of the V phase of the motor, Iw denotes a current of a W phase of the motor, and Dw denotes the PWM duty signal of the W phase.

Abstract: A tank-integrated pump unit includes a reservoir tank fixed to a pump body. The body of the reservoir tank includes an introduction opening for introducing working fluid from an external hydraulic device into the body. A filter member is arranged in the body for filtering working fluid introduced through the introduction opening. A suction passage connection portion is connected to a suction hole of a pump body. The suction passage connection portion includes a body-side opening through a wall of the body. The body-side opening is located below a predetermined level of working fluid and above a lowermost position in the body. A pressure chamber is defined in the body, and located below the body-side opening of the suction passage connection portion. The introduction opening faces the pressure chamber. The filter member covers an upper side of the pressure chamber.

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: Torque sensor has: magnetic member; first yoke member having (a) first nail portions arranged concentrically to face the magnetic member in radial direction and (b) first ring portion; second yoke member having (c) second nail portions arranged concentrically so that the first and second nail portions are circumferentially alternately arranged and the second nail portions face the magnetic member in radial direction and (d) second ring portion; first magnetic flux concentration ring provided between the first and second ring portions; second magnetic flux concentration ring provided between the second ring portion and the first magnetic flux concentration ring; and magnetic sensor. The first and second magnetic flux concentration rings and the first and second ring portions are arranged in layers in radial direction. A part or all of axial direction area of the first and second magnetic flux concentration rings is surrounded and shielded by the second ring portion.

Abstract: In a power steering system, at least one of phase open relays in which a contact weld (an abnormality) occurs is detected. That is to say, the power steering system comprises an abnormality monitor section (57) configured to output vector control command signals to supply only a d-axis current in a positive side direction toward the motor, with all of phase open relays (58v, 58w) in an interruption state, and to determine an abnormality in at least one of the phase open relays in a case where a current value is detected by a current detection circuit which detects a current flowing into an inverter. In a case of three phase open relays installed between respective three phases of motor windings, a potential difference is detected at a neutral position of a star connection to determine the abnormality of at least two of the phase open relays.