Nsk Corporation

Toshihiro Fukuda

Hiroshi Eda

Osamu Tatewaki

Jun Okada

Osamu Saito

Shuji Endo

Kenichi Hayakawa

Hirotaka Hatano

Hiroyuki Ito

Hisashi Machida

Kazuo Chikaraishi

Ryoichi Otaki

Tamotsu Oumi

Yasuhide Nomura

Mineki Okamoto

Osama Tatewaki

An electric power steering apparatus that driving-controls a motor via inverters based on a current command value, and applies an assist force by the motor to a steering system, includes multi-system driving systems with the inverters for respective system-windings of the motor which is a multi-system motor, wherein respective multi-system current command value characteristics against a steering torque are applied so as to be disproportionate for left and right steering, to the respective multi-system driving systems, and an assist-control is performed in response to the individual current command value characteristics.

Electric power steering apparatus

An electrically driven power steering apparatus is structured such that a large impact on a rack shaft occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing of a presser member becomes zero, a rotation of the presser member is hindered by caulking c at a thin plate member. Therefore, the presser member does not slacken, and a predetermined axial force can be given again to the ball bearing when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.

Electrically driven power steering apparatus

An electric power steering apparatus comprises a rotary shaft member connected to a steering wheel, an elongate member, a rack-and-pinion mechanism, a ball screw mechanism constructed of a screw member, a nut member and a multiplicity of balls interposed between the screw member and the nut member, an electric motor unit, and a meshing type rotation decelerating mechanism including a plurality of meshing components. The meshing components include an output shaft pinion gear, a deceleration gear, and an intermediate gear, interposed between the output shaft pinion gear and the deceleration gear, having a contact portion composed of a synthetic resin.

An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.

An electrically driven power steering apparatus is structured such that a large impact on a rack shaft () occurs upon an impingement of a steering stopper, and, even when an axial force acting on a ball bearing () of a presser member () becomes zero, a rotation of the presser member () is hindered by caulking c at a thin plate member (). Therefore, the presser member () does not slacken, and a predetermined axial force can be given again to the ball bearing () when the impact dissipates. The thus structured power steering apparatus exhibiting, though the cost is low, an excellent shockproof characteristic and capable of preventing the bearing from coming off a ball screw nut, can be provided.

Motor-operated power steering apparatus

An electric power steering apparatus comprises an electric motor having a motor housing, a ball screw mechanism connected to the electric motor through power transmission means and used for driving a rack shaft, and a steering gear case encasing the rack shaft and the ball screw mechanism. The electric motor is supported by at least two supporting portions with respect to the steering gear case, and is supported by at lest one of the two supporting portions through an elastic member.

An electric power steering apparatus includes a power assist mechanism encased by a steering gear case, an electric motor coupled to the power assist mechanism, a power transmission mechanism, coupled to the electric motor and the power assist mechanism, and a protection cover, separate from the electric motor casing and attached thereto, for covering the electric motor.

Motor-operated power steering device

An easy-to-assemble electric power steering device, in which an approximately cylindrical housing is divided at about the central part into a first chamber and a second chamber. The first chamber is for housing a motor for assisting the steering force. A stator of the motor is inserted at one end of the housing and fixed. The second chamber is for housing a rack shaft assembly which comprises a rack shaft connected with the steering shaft and a ball screw mechanism. The rack shaft assembly is inserted at the other end of the housing, to thereby spline a rotor of the motor for assisting the steering force with a nut of the ball screw mechanism. A bearing supporting the nut of the ball screw mechanism is axially movably held in the inner wall of the second chamber. The rack shaft is arranged through the first and second chambers of the housing.

Electric power steering device

A frictional transmission comprises first and second rotary shafts arranged in directions in which the central axes thereof crossed each other, a roller supported coaxially with the first rotary shaft for rotating with the first rotary shaft, a first frictional surface provided on the roller coaxially with the first rotary shaft, a disc supported coaxially with the second rotary shaft for rotating with the second rotary shaft, and a second frictional surface provided on this disc coaxially with the second rotary shaft. The second frictional surface and the first frictional surface are brought into frictional engagement with each other. A loading cam device is arranged so as to press the second frictional surface toward the first frictional surface at the time of driving. A further disc coaxial with the aforementioned disc is disposed in the environs of the second rotary shaft, and the roller is sandwiched by and between the two discs. This further disc is rotatably supported by an angular-type ball bearing relative to the second rotary shaft and the first-mentioned disc in the environs of the second rotary shaft in a state that this further disc is prevented from being displaced in a direction to be separated from the first-mentioned disc.

Growing community of inventors

Gunma-ken, Japan

Toshihiro Fukuda