Nsk Corporation

Nsk Steering Systems Co., Ltd.

Jun Okada

Hiroshi Eda

Toshihiro Fukuda

Osamu Tatewaki

Osamu Saito

Since a nutis provided with paths for connecting rolling pathsand circulating paths, that is, return pathsat end capsattached to both ends of a main body, a receiving portion for receiving power transmitted from an electric motor, that is, a driven gear portionsis provided at a center of an outer peripheral face on outer sides in a radius direction of the rolling paths and therefore, when power is transmitted from the electric motorto the driven gear portion, smooth operation can be carried out by restraining the nutfrom being twisted.

Electric 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 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.

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.

Growing community of inventors

Gunma-ken, Japan

Jun Okada