Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Jx Nippon Oil Energy Corporation

Hitachi Automotive Systems Steering, Ltd.

Jxtg Nippon Oil & Energy Corporation

Tatsuro Suzuki

Takashi Arai

Kohtaro Shiino

Satoshi Taniuchi

Masaki Kashima

Yusuke Fukuda

Kazumi Sakai

Kazuya Yamano

Yuji Shitara

Atsushi Yoshitake

Atsushi Hirata

Eiichiro Ito

Tatsuro Mitsuhira

A steering device includes: an offset correction value storing section to store an offset correction value including a first offset correction value and a second offset correction value, the first offset value being a current value for correcting the first sensed current signal so that a value of a vibration of the electric motor is equal to or smaller than a first predetermined value when the motor rotation speed signal is a first rotation speed, and the second offset value being a current value for correcting the first sensed current signal so that the value of the vibration of the electric motor is equal to or smaller than a second predetermined value when the motor rotation speed signal is a second rotation speed.

Steering device

A motor is contained in a motor container space. A controller is contained in a controller container space. The motor container space and the controller container space are arranged in series in a direction of a rotation axis of a motor shaft, while interposing a partition wall therebetween. The motor shaft is inserted in a motor shaft through-hole of the partition wall. A magnet is disposed at an end of the motor shaft, in the controller container space. A rotation sensor is disposed in the controller container space oppositely to the magnet, for monitoring a rotational position of the motor shaft on the basis of variation in magnetic field due to rotation of the magnet. A cover made of nonmagnetic metal is disposed between the magnet and the rotation sensor so as to cover the motor shaft through-hole.

Actuator for in-vehicle unit

Provided are both a grease composition for an electric power steering device and an electric power steering device. The grease composition can keep a sufficiently low coefficient of friction in a sliding area between a steel and a resin over a long period, is less susceptible to being removed from the sliding area, does not cause break down of an oil film, and thus can minimize the occurrence of stick-slips. A grease composition for an electric power steering device, containing a synthetic hydrocarbon oil which exhibits a density of 0.75 to 0.95 g/cmat 15&#xb0; C., a saturated aliphatic amide compound, boron nitride, a glycerin fatty acid partial ester, and a metal soap-based thickener; and an electric power steering device using the grease composition.

Grease composition for electric power steering device, and electric power steering device

A power steering apparatus including a joint including a first boss disposed on an axial end portion of a motor output shaft, first projections disposed on the first boss in the circumferential direction, a second boss disposed on an axial end portion of a worm shaft and opposed to the first boss, second projections disposed on the second boss in the circumferential direction and arranged between the adjacent first projections, a first elastic member made of metal and a second elastic member made of at least one of resin and rubber, the first and second elastic members being disposed between an axial end surface of the first boss and an opposed axial end surface of the second boss and cooperating with each other to generate an elastic force in such a direction as to move the worm shaft away from the motor output shaft.

Power steering apparatus

A power steering apparatus includes a worm wheel mounted on the steering shaft, a worm shaft engaged with the worm wheel, a gear housing having a wheel accommodating portion to accommodate the worm wheel and a shaft accommodating portion to accommodate the worm shaft, a bearing mounted on the worm shaft to rotatably support the worm shaft, a holder disposed in the shaft accommodating portion and having a bearing retaining portion to retain the bearing and a resilient element disposed in the shaft accommodating portion and having a resilient body portion formed with a curvature. The resilient body portion is so structured as to become deformed in such a manner as to increase or decrease in diameter when the bearing shifts in a direction that moves the worm shaft away from the worm wheel and bias the bearing in a direction that urges the worm wheel toward the worm wheel.

A worm wheel including an annular worm wheel main body formed from a resin material; teeth on an outer periphery of the worm wheel main body in a circumferential direction of the worm wheel main body a; a first region on respective tooth flanks of the teeth and offset from a mid-position of a whole depth of the respective teeth in a radially outward direction of the worm wheel main body; a first region; and a second region.

Growing community of inventors

Atsugi, Japan

Tatsuro Suzuki