Koyo Seiko Company, Ltd.

Gates Unitta Asia Company

Jtekt Corporation

Takehiro Saruwatari

Kunihiro Oka

Kensaku Nakamura

Akihiro Hironaka

Hiroshi Murataka

Atsuya Miyata

Tetsuya Murakami

Kazuaki Nagamatsu

Hiroto Sasaki

Masanori Arima

Kousuke Yamanaka

Osamu Sano

Masato Mizuhara

Yasuhiro Kamatani

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.

Electric power steering apparatus and method for controlling same

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.

Electric power steering apparatus

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.

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.

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.

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.

Steering apparatus for vehicle

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.

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.

Vehicle steering apparatus

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. In an electric power steering system, the support shaft formed with the first bevel gear at its distal end is allowed to move toward the second bevel gear and is biased by the biasing member toward the second bevel gear, so that the first bevel gear is moved toward the second bevel gear according to the wearing away of these bevel gears.

Growing community of inventors

Kashiwara, Japan

Takehiro Saruwatari