Jtekt Corporation

Koyo Seiko Company, Ltd.

Other

Shirou Nakano

Katsutoshi Nishizaki

Ryouhei Hayama

Yoshikazu Kuroumaru

Takayasu Yamazaki

Masaya Segawa

Shigeki Nagase

Masahiko Sakamaki

Ken Matsubara

Takanobu Takamatsu

Shingo Maeda

Takeshi Ueda

Toshiaki Oya

Naoki Maeda

Naotake Kanda

Tomoyasu Kada

Kenji Higashi

Minoru Sentoku

Masayasu Higashi

Masanori Arima

Hideki Higashira

Yasuyuki Yoshii

Kazuhiro Kato

Shuuji Kimura

Takeo Iino

Yasuhiro Saitou

Yasuhiro Kamatani

Shinsuke Terada

Masayuki Ueno

Youjirou Kakoki

Sachio Yoshida

Hironori Yamato

Takeshi c/o Jtekt Corporation Ueda

Yasuhiro c/o Jtekt Corporation Saitou

A controller applies slight rotational torque to a drive gear of a reduction mechanism also in a predetermined range in which a motor does not produce any steering operation assist force. That is, the motor is caused to produce slight rotational torque not enough to drive a driven gear, and the rotational torque direction is reversed under a given condition. Accordingly, a backlash between the drive gear and the driven gear is eliminated.

Electric power steering system

A rack-and-pinion steering apparatus comprises pinion teeth formed according to proper tooth specifications in other aspects under a larger pressure angle, thereby stably offering smooth and comfortable steering feeling over a long time. The module (m), number of teeth (z), tooth depth (h) and helix angle (&#x3b2;) of the pinion teeth () are set within the following ranges, under a pressure angle (&#x3b1;) set within a range of 24&#xb0; to 30&#xb0; and a given stroke ratio.

Rack-and-pinion steering apparatus

A rack and pinion steering apparatus which does not need quenching of the rack shaft after gear cutting of the rack shaft in manufacturing processes is provided. The rack and pinion steering apparatus comprises a pinion shaft and a rack shaft meshing with the pinion shaft. The rack shaft is formed to have a substantially uniform hardness.

Rack and pinion steering apparatus and method of manufacturing rack shaft

An electric power steering system is provided which is capable of providing a favorable steering feeling without using compensation logics such as of inertia compensation and friction compensation. The electric power steering system includes road-noise suppression control means () for controlling a steering assist motor () in a manner to damp torque transmission in a higher frequency region representing road noises than a frequency region representing road information. A friction value of a steering mechanism (A) is decreased enough to allow the intrinsic vibrations of the steering mechanism (A) to appear. Rotor inertia of the steering assist motor () is set to a value small enough to allow the frequencies of the intrinsic vibrations to be present in the frequency region where the torque transmission is damped by the road-noise suppression control means ().

The invention provides a motor-driven power steering apparatus which can achieve a predetermined speed reduction ratio even in the case that the motor-driven power steering apparatus is constituted by a pair of spur gears or helical gears, and can secure a sufficient gear strength on the basis of a simple structure. In a motor-driven power steering apparatus in which a rotating torque of an electric motor () is transmitted to a steering shaft by a drive gear () provided in an output shaft of the electric motor () and a driven gear () provided in the steering shaft, and a speed reduction ratio is equal to or more than 3, the steering shaft and the output shaft of the electric motor () are arranged in almost parallel, a center distance between both the shafts is equal to or more than 35 mm and equal to or less than 90 mm, and the drive gear () is configured such that a number of teeth is equal to or more than 6 and equal to or less than 15, a module is equal to or more than 0.8 and equal to or less than 1.5, a tooth depth is equal to or less than 2.4 times of the module, and a pressure angle is equal to or more than 14.5 degrees and equal to or less than 30 degrees, and a torsion angle is equal to or more than 0 degrees and equal to or less than 40 degrees.

Motor-driven power steering apparatus

A reduction gear unit capable of reducing vibrations caused by gear rattle, while permitting some degree of backlash in a pair of gears, is provided. A reduction gear unit is so configured that a pinion shaft and a main gear shaft are disposed in parallel to each other, and a pinionmounted on the pinion shaft and a main gearmounted on the main gear shaft are arranged to mesh with each other, so as to transmit a rotation of the pinion shaft to the main gear shaft, and includes a housingthat encloses the pinionand the main gearwhere the housinghas an inner surface whose width, in a cross section perpendicular to an axial direction of the pinion shaft and the main gear shaft, perpendicular to an imaginary line that connects centers of the pinion shaft and the main gear shaft evenly increases from a pinion side toward a main gear side between ends of arcuate regions respectively enclosing the main gear and the pinion. The housingcontains a resin lubricant of a sufficient amount for immersing a part of a portion where the pinionand the main gearmesh with each other.

Reduction gear unit

A second housing is aligned with a first housing at a predetermined position using positioning means that determines the mounting position of the housing with respect to the first housing at the predetermined position; steering shaft supporting sections and output shaft supporting sections are provided in the first housing and the second housing respectively while the housings being mounted using screws or the like; the second housing is removed temporarily from the first housing; a steering shaft and an output shaft are supported using the steering shaft supporting sections and the output shaft supporting sections; and the second housing is aligned again with the first housing at the predetermined position using the positioning means and mounted.

Method for producing electric power steering apparatus

The present invention provides a rack-and-pinion steering apparatus capable of effectively reducing reverse input, while a high degree of design freedom is secured. The sum of the tilt angle of a rack tooth with respect to a reference line perpendicular to the axial line of a rack shaft and the tilt angle of a pinion tooth with respect to the axial line of a pinion shaft does not coincide with the tilt angle of the axial line of the pinion shaft with respect to the reference line. Crowning is given on the tooth surface of the rack tooth (or the pinion tooth) in order to decrease the tooth width on one end side in the direction of tooth trace and to increase the tooth width on the other end side according to the state of contact with the pinion tooth (or the rack tooth) opposed thereto.

A sensor includes a stator having four or more magnetic pole teeth and concentric with a stationary-side raceway member, and excitation coils and detection coils wound around the respective magnetic pole teeth. Signals generated in the detection coils according to distances between the magnetic pole teeth and a rotation-side raceway member are taken out for the respective magnetic pole teeth. The load acting on a rolling bearing is obtained in processing means from these signals.

Sensor-equipped rolling bearing unit

An object of the present invention is to provide a vehicle steering apparatus that detects the tire load, and based on the detected tire load, performs steering control which accurately reflects the road conditions. A vehicle steering apparatus of the present invention includes a control unit, which controls a steering actuator in accordance with the operation of a steering wheel. An operation reaction force generated by a reaction force actuatoris applied to the steering wheel. Within the tire W, stress sensors SL and SR and an air pressure sensor SP are provided. The control unitcontrols the steering actuatorand the reaction force actuatorwith referring to the tire load detected by these sensors.

Vehicle steering apparatus

A first alternating signal of which phase changes according to changes in the rotation angle of a first shaft is output, and a second alternating signal of which phase changes according to changes in the rotation angle of a second shaft capable of rotating elastically with respect to the first shaft is output. A phase difference correspondence signal of which waveform changes according to changes in the phase difference between the first alternating signal and second alternating signal is output. A value corresponding to the torque transmitted by the first and second shafts is found from the phase difference correspondence signal.

Torque sensor

In a vehicle steering apparatus, a steering actuator is controlled so that the steering angle varies in accordance with the operation of an operating member. A transmission mechanism connects an operating side rotating member that is mechanically connected to the operating member and a vehicle wheel side rotating member that is mechanically connected to the vehicle wheels so that the mutual transmission of rotation is possible. Furthermore, the rotational transmission ratio between the operating side rotating member and the vehicle wheel side rotating member can be varied.

A steering actuator can be controlled such that the ratio between amount of operation of an operating member and amount of steering of vehicle wheels changes. Movement of the steering actuator is transmitted to the vehicle wheel such that variation in steering angle is generated. A relationship between behavior index value for operating corresponding to change in behavior of the vehicle caused by change in steering angle, target behavior index value for operating corresponding to amount of operation of the operating member, and target operating torque is stored. The target operating torque is calculated from the stored relationship, the determined behavior index value for operating, and the determined target behavior index value for operating. An operating actuator for generating torque which acts upon the operating member is controlled such that the operating torque of the operating member corresponds to the target operating torque.

The steering device for vehicle changes the steering angle by transmitting the movements of the steering electrical actuator to the vehicle wheels. When the vehicle is steered in the stationary state, the hydraulic fluid can be supplied to the steering assistance force generating hydraulic actuator from the pump within the hydraulic pressure imparting unit. When the vehicle is not steered in the stationary state, the hydraulic fluid can be supplied to the brake device from the pump via the hydraulic pressure distribution unit.

Steering device for vehicle

In a steering device, the rotation of the input shaft corresponding to the steering operation is transmitted to the output shaft via a rotation transmission mechanism, and is transmitted from the output shaft to the wheels of the vehicle by a steering gear so that the steering angle varies. A control device controls an electromotive actuator used to drive a constituent element of the rotation transmission mechanism in accordance with a variable quantity that expresses the traveling conditions of the vehicle, on the basis of the respective detection values of an input sensor used to detect the amount of input into the input shaft, an output sensor used to detect the amount of output of the output shaft and a traveling condition sensor used to detect the variable quantity that expresses the traveling conditions of the vehicle, so that the ratio of the transmission of rotation from the input shaft to the output shaft is altered in accordance with the variable quantity that expresses the traveling conditions.

Growing community of inventors

Minamikawachi-gun, Japan

Shirou Nakano