Abstract: In a steering system, an operation mechanism that includes an operation member includes: a steering angle sensor that detects a steering angle of the operation member; and a steering direction detection unit that detects a steering direction of the operation member. The steering direction detection unit includes: a threaded shaft that is rotatable in the steering direction of the operation member; a nut that is screwed to the threaded shaft; a nut guide that causes the nut to move in accordance with rotation of the threaded shaft; a stopper that prevents movement of the nut beyond a predetermined position; a proximity detection sensor that detects a fact that the nut is in proximity to the stopper; and a variable axial length mechanism that reduces a clearance between the nut and the stopper in response to occurrence of a malfunction in the steering angle sensor.

Abstract: When clamped side plates of an upper column bracket (movable bracket) are fastened via clamping side plates of an upper fixed bracket by a fastening shaft in response to a rotating operation of an operating lever, the brackets are locked with each other. A pressing mechanism that includes a pressing member moves in the axial direction of the fastening shaft in accordance with fastening by the fastening shaft, and presses a lower tube (inner tube) through an insertion hole formed in an upper tube (outer tube). The entirety of the axial force of the fastening shaft is used as a retaining force for retaining the posture of a steering column.

Abstract: An electric power steering system includes: an annular elastic member that is made of resin, that is arranged between an inner end face of a housing and an outer ring of a bearing that supports a cylindrical member that rotates coaxially with a rack shaft, and that supports the cylindrical member such that the cylindrical member is movable in the axial direction with respect to the housing; and a supporting member that restricts axial movement of the cylindrical member within a predetermined range, and that restricts radially inward movement of the elastic member.

Abstract: In a motor controller, a current detection unit detects an electric current flowing through a brushless motor. An open loop control unit determines a command value indicating a level of a command voltage in accordance with a motor circuit equation, based on a command current value indicating an amount of electric current to be supplied to the brushless motor and an angular velocity of a rotor in the brushless motor. A correction unit calculates a correction value based on a difference between the command current value and a current value detected by the current detection unit when the electric current is detected by the current detection unit and corrects the command value according to the correction value, and corrects the command value according to the correction value even when an electric current is not detected by the current detection unit.

Abstract: An electric power steering apparatus drives a motor to generate a steering assist force according to a steering torque and includes an output circuit for supplying the motor with electric power from at least one of a battery and an auxiliary power supply. The electric power steering apparatus has a control circuit which at or after detection of a breakdown of the battery, determines a length of time to the end of steering assist (decreasing time t1) based on the amount of energy stored in the auxiliary power supplies and which takes the determined length of time to perform output decreasing control to gradually decrease the upper limit of power supplied for the steering assist to practically zero according to a constant gradient. Thus is provided an electric power steering apparatus which is adapted to prevent a sudden fall of the steering assist force in the event of a battery breakdown while effectively utilizing the available stored energy.

Abstract: The multi-stage reducer includes a first-stage reduction part to which the rotation from a motor is input and a second-stage reduction part to which the rotation having undergone speed reduction by the first-stage reduction part is input. The second-stage reduction part is disposed on an outer circumference of the first-stage reduction part.

Abstract: When a vehicle is quickly steered while the vehicle is travelling at an extremely low speed, a load on an in-vehicle power supply is reduced without deteriorating a steering feeling by reducing a motor driving current. A steering speed is compared with a threshold. When the steering speed is lower than the threshold, the process proceeds to step S6. In step S6, a voltage value of a battery power supply, which is used as a prescribed value, is set as a limit voltage in order to reduce a motor consumption current. When the steering speed is higher than the threshold, a value “V0/n” lower than the prescribed value is set as the limit voltage to reduce a consumption current when the steering wheel is steered without driving. “n” is “delay adjustment parameter”, and is a real number that exceeds 1.

Abstract: A motor vehicle steering system includes a knob that is for rotating a wheel of a steering member, has a knob center, and is supported rotatably around the knob center by the wheel. A control unit sets a predetermined period after detection of gripping on the knob by a grip detection device as a transfer period for transfer from reaction force application only by a wheel reaction force actuator to reaction force application only by a knob reaction force actuator. In the transfer period, the knob reaction force is increased with time and the wheel reaction force is reduced with time.

Abstract: A rolling bearing unit for a wheel includes an outer ring member having a flange portion formed on its outer periphery and fitted to a vehicle body-side member, an inner ring member rotatably fitted in the outer ring member, and double-row rolling elements arranged between the outer ring member and the inner ring member. The flange portion includes a first flange portion formed on the upper-side portion of the outer periphery, and a second flange portion and a third flange portion formed on the lower-side portion of the outer periphery. Each of the first, second and third flange portion has a bolt-hole used to fit the outer ring member to the vehicle body-side member. The first flange portion is formed in such a manner that the bolt-hole thereof is positioned on the vertical line that passes through the rotational center of the outer ring member.

Abstract: In an electric power steering apparatus of the invention, a control circuit determines a command value of drive voltage supplied to a motor drive circuit based on an actual current through a motor and a target current. When the command value exceeds the previous value having a lower limit equivalent to a limit value representing the limit of the power supply from a battery, the control circuit controls the amount of discharge from the auxiliary power supply according to a difference between the command value and the previous value by increasing or decreasing a duty of switching devices. Thus, the power steering apparatus can save the energy of the auxiliary power supply for efficiently using the auxiliary power supply.

Abstract: In an internal gear pump that includes an inner gear having outer teeth and an outer gear having inner teeth, either the inner or outer teeth have a shape based on a tooth shape that is respectively formed by a generating curve of the outer or inner teeth. The inner teeth are arc-shaped, the outer teeth are curved-shaped, and both end sections of the curved shape are arc-shaped. If a radius of the arc shape of the inner teeth is set as ro, a radius of the arc shape of each of the corner sections is set as ri, a diameter of a pitch circle of the inner teeth is set as dp, and the number of the inner teeth is set as z, the inner gear and the outer gear each has a shape that satisfies a relationship established by following equations: 1.6>ro/(dp/z)>1.0; and ro/(dp/z)>ri/(dp/z)?0.13.

Abstract: The invention relates to a method for securing the assistance torque (15) supplied by an electric assistance motor (8) in a motor vehicle power steering system, the securing method being characterized in that it includes the steps of: estimating the force on the steering system rack from the torque exerted by the driver on the steering wheel (2), from the assistance torque (15), and optionally from other parameters such as the speed of the electric assistance motor; comparing a target assistance torque with an authorized assistance range, defined with respect to the estimated rack force (17) at any moment, and in the event the target assistance torque is maintained above predefined limits for a predefined duration, correcting and optionally interrupting the power steering.

Abstract: A bearing apparatus to be supported by an axle box which includes a key groove, the bearing apparatus includes an outer ring which includes a first key groove extending from an inner diameter to an outer diameter of an axial end surface of the outer ring, an inner ring, rolling elements rollably interposed between the outer and inner rings, and a key member which includes an annular body, a first inwardly projecting part which is provided on the annular body and adapted to be inserted into the first key groove of the outer ring, and an outwardly projecting part which is provided on an outer periphery of the annular body and adapted to be inserted into the key groove of the axle box.

Abstract: A curvature radius of a raceway groove of an inner ring of a first bearing supporting a first end portion of a worm shaft and a curvature radius of a raceway groove of an outer ring of the first bearing are larger than 50% of a diameter of each rolling element of the first bearing, whereby the worm shaft is pivotable about the first end portion. Internal clearances in the first bearing are eliminated because the first bearing is pressed in a radial direction by a pressing member. When the worm shaft vibrates relative to a housing in an axial direction, paired second elastic members and damp and absorb the vibration.

Abstract: When a partial malfunction is detected, a sensor malfunction determination unit changes a control mode from a first control mode to a second control mode. When the control mode is changed from the first control mode to the second control mode, a steered system motor is rotated in a direction corresponding to a rotation direction of a steering wheel immediately before the partial malfunction occurs in the angle sensor. When the absolute value of a steering angular velocity of the steering wheel exceeds a threshold, it is determined that a driver has operated the steering wheel in a direction opposite to a current steered direction, and the rotation direction of the steered system motor is reversed.

Abstract: In a reduction-transmission mechanism, a plurality of output members are arranged at such positions that a size that is the sum of a fitting clearance formed between an outer periphery of each output member and a corresponding one of needle roller bearings, a fitting clearance formed between the needle roller bearing and an inner periphery of an input member, which defines a corresponding one of a plurality of pin insertion holes, and a radial internal clearance in the needle roller bearing is smaller than a size that is the sum of a fitting clearance formed between a ball bearing and an outer periphery of an eccentric portion, a fitting clearance formed between the ball bearing and an inner periphery of the input member, which defines a center hole, and a radial internal clearance in the ball bearing.

Abstract: A sliding type tripod constant velocity joint includes an outer ring of a tubular form having three raceway grooves which are formed on an inner peripheral surface and which extend in a direction of a rotation axis of the outer ring, a tripod including a boss part connected to a shaft and three tripod shaft parts which are provided upright so as to extend outward in a radial direction of the boss part from an outer peripheral surface of the boss part and which are inserted into the raceway grooves, respectively, and a pair of intermediate members which are arranged so as to sandwich a corresponding one of the tripod shaft parts from both sides of side surfaces of the raceway grooves and which are provided so as to be oscillated relative to the corresponding one of the tripod shaft parts.

Abstract: A vehicle steering system includes: a steering member; steered wheels; a steered shaft; a housing; a fitting bracket that has a first bolt insertion hole; a vehicle body-side member that has a second bolt insertion hole; and a bolt that is inserted through the first bolt insertion hole and the second bolt insertion hole. One of the first bolt insertion hole and the second bolt insertion hole is a long hole. When a reverse input equal to or larger than a predetermined value is applied from a road surface to the steered wheel, the bolt is displaced within the long hole in the lateral direction, causing the fitting bracket to displace with respect to the vehicle body-side member in the lateral direction.

Abstract: A pump housing, a fixing member and a holding member are assembled in the axis direction of an oil pump to fix a stator and a rotor of a brushless motor. The holding member is made of metal material and has a cylindrical shape that extends from its bottom portion toward one side in the axial direction. The fixing member is a cylindrical metal member. Stepped portions, extending in the circumferential direction, are formed in the outer periphery of the holding member and the inner periphery of the fixing member, and contact each other. The outer periphery of the holding member engages with the inner periphery of the fixing member. The outer periphery of the other end portion of the fixing member is fitted to the inner periphery of a flange portion projecting from the end face of the pump housing, which is adjacent to the brushless motor.

Abstract: There is provided an urging mechanism that elastically urges a second end portion of a worm shaft that is supported so as to be pivotable about a first end portion. The urging mechanism is configured to adjust a backlash between the worm shaft and a worm wheel by elastically urging the second end portion in a perpendicular direction that is perpendicular to a direction in which an inter-axis distance between the worm shaft and the worm wheel increases and decreases, in a state where increases and decreases in the inter-axis distance is prevented.