Abstract: In a control method for an electric power steering apparatus having a steering member, a steering mechanism, and a motor for assisting steering, a steering torque applied to a steering wheel is detected, frequency analysis is performed on the detected torque, and a determination is made as to whether or not a torque component having a frequency equal to or higher than a predetermined value is included in the result of the frequency analysis. When such a torque component is included in the frequency analysis result, a predetermined rotary torque is generated in a single direction.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: In a control method for an electric power steering apparatus having a steering member, a steering mechanism, and a motor for assisting steering, a steering torque applied to a steering wheel is detected, frequency analysis is performed on the detected torque, and a determination is made as to whether or not a torque component having a frequency equal to or higher than a predetermined value is included in the result of the frequency analysis. When such a torque component is included in the frequency analysis result, a predetermined rotary torque is generated in a single direction.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: A reduction gear mechanism includes mutually meshing smaller gear and larger gear with their shafts arranged parallel to each other; a first rotor which rotates together with the smaller gear; and a second rotor which rotates together with the larger gear, so as to generate sliding friction between the first rotor and itself in the reverse rotation direction of one of the smaller gear and larger gear. When a relative speed is generated between the smaller gear and larger gear by reverse rotation of one of the smaller gear and larger gear, resistance is applied to the reverse rotation of one of the gears and the relative speed is decreased to reduce rattling noise which is made when the surfaces of their teeth come into contact with each other.

Abstract: An electric power steering apparatus for converting rotation of a steering assist motor into movement of a steering shaft in the axial direction thereof in accordance with steering operation using a ball screw mechanism wherein a female thread groove formed around an inner circumference of a rotating cylinder rotated around the axis thereof by the motor and a male thread groove formed around an outer circumference of the steering shaft are screwed with each other via a plurality of balls. The portions, where the both thread grooves contact with the balls, are formed in a circular arc shape, respectively, and the curvature of the female thread groove is made smaller than that of the male thread groove. Hence, the ball screw mechanism wherein skew occurrence between the ball and both the thread grooves is prevented and the dimensional errors of both the thread groove are decreased is realized.

Abstract: An electric power steering apparatus comprises an electric motor for producing a steering assist force, and a speed reduction mechanism for decelerating the rotation of an output shaft in the electric motor. The speed reduction mechanism comprises an input pulley driven by the electric motor, an output pulley connected to a steering shaft, and a belt for connecting the input pulley and the output pulley to each other. The belt comprises a helical toothed belt. The input pulley and the output pulley respectively include helical toothed pulleys meshed with the helical toothed belt.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other and a belt tension adjuster.

Abstract: A nut member which is rotated by power transmission from a motor in a rack housing is supported by a thrust bearing fitted and fixed in a first housing having an integrally formed fixing section for fastening to a vehicle body so that the nut member cannot move in both directions along an axial direction. Thrust loads applied in both directions to the nut member with the conversion of rotation into movement of a steering shaft in an axial direction are carried by the first housing through the thrust bearing. The structure of the connection section of the first housing and second housing is simplified, and the housing is fixed in a stable manner to prevent deterioration in steering feeling.

Abstract: An electric power steering apparatus comprises a speed reduction mechanism for decelerating the rotation of an output shaft in an electric motor for steering assist. The speed reduction mechanism comprises a driving gear connected to the output shaft in the electric motor and a driven gear meshed with the driving gear. One of respective tooth sections in the driving gear and the driven gear includes a tooth section formed of a material having a relatively low hardness, and the other tooth section includes a tooth section formed of a material having a relatively high hardness. The profile of the tooth section formed of the material having a relatively low hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is increased. The profile of the tooth section formed of the material having a relatively high hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is decreased.

Abstract: In a vehicle steering apparatus, a rotating cylinder supported by a rack housing is threadingly engaged via rolling elements with a screw shaft integrated with a rack which meshes with a pinion which rotates by steering operation. The rotating cylinder is driven by a motor. All of the rolling elements are arranged between a rack support member which supports the rack in the position where the rack is meshed with the pinion, and a support body that is arranged in the movement range of the screw shaft and is capable of supporting the outer circumference of the screw shaft. Loads acting on the rack from the road surface are received by the support body and the rack support member.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: In an electric power steering system, a second bevel gear is allowed to move toward a first bevel gear and is biased by a biasing member toward the first bevel gear thereby to be moved toward the first bevel gear as following the wearing away of these bevel gears. In an electric power steering system, a support shaft formed with the first bevel gear at its distal end is rotatably supported by a retaining member, which is mounted to a support-shaft housing as allowed to move axially of the support shaft. The retaining member is adjusted for its position relative to the support-shaft housing with respect to the axial direction of the support shaft by means of a retaining member adjuster. The first bevel gear is moved toward the second bevel gear as following the wearing away of these bevel gears.

Abstract: An electric power steering apparatus including: a steering rack shaft which has an external thread with a flat crest and can be moved in the axial direction in response to a steering operation; a ball screw mechanism, which has a nut screwed onto the external thread via balls so as to be relatively rotational, for transforming the rotational force of the electric motor into movement force in the axial direction and transmitting the movement force to the steering rack shaft; and a cylindrical member, which is fitted on the steering rack shaft, for depressing the deflection amount of the steering rack shaft, wherein the width of the flat crest of the external thread is 0.7 to 1.5 times as long as the diameter of the balls. The inner surface of the cylindrical member hardly abrades away even when the external thread contacts with the inner surface of the cylindrical member.

Abstract: An electric power steering apparatus comprises a speed reduction mechanism for decelerating the rotation of an output shaft in an electric motor for steering assist. The speed reduction mechanism comprises a driving gear connected to the output shaft in the electric motor and a driven gear meshed with the driving gear. One of respective tooth sections in the driving gear and the driven gear includes a tooth section formed of a material having a relatively low hardness, and the other tooth section includes a tooth section formed of a material having a relatively high hardness. The profile of the tooth section formed of the material having a relatively low hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is increased. The profile of the tooth section formed of the material having a relatively high hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is decreased.