Koyo Seiko Company, Ltd.

Jtekt Corporation

Other

E.i. Dupont De Nemours and Company

Asahi Organic Chemicals Industry Co., Ltd.

Takanori Kurokawa

Hirokazu Arai

Akihiko Shiina

Katsura Koyagi

Kouji Kitahata

Hideo Matsubara

Atsuo Suehiro

Yoshifumi Niide

Syouji Sawai

Shinichi Tahara

Shingo Nakamura

Kouichi Taniguchi

Takeshi Tojo

Kenichi Shinohara

Masahiro Tabata

Michitoshi Mitsumaru

Mitsuharu Minami

Masashi Kuze

Toshihiko Kaneiwa

Masamitsu Ohtsubo

Kikuo Yamashita

Tetsuya Minamiguchi

A parallel shaft gear mechanism () for a steering assist of the present electric power steering apparatus () includes an idle gear () rotatably supported via a rolling bearing (), on an outer peripheral surface () of an intermediate shaft () supported by a rack housing (). The idle gear () is arranged in an annular synthetic resin member () fixed on the outer peripheral surface () of an outer ring () of the bearing (). On the outer peripheral surface () of the outer ring (), a regulating portion (A,B,C,D,E,F,G,A,B,C,D,E,F,A,B,A, andB) for regulating relative rotation between the outer ring () and the synthetic resin member () is arranged. The synthetic resin member () is formed in a manner to cover the regulating portion on the outer peripheral surface () of the outer ring (), as a result of a molding process using a mold.

Electric power steering device

A gear for an electric power steering device for reducing the rotation speed of an electric motor for steering assist with a reduction gear mechanism and transmitting the rotation to a steering mechanism, the gear being incorporated and used in the reduction gear mechanism, wherein at least the teeth of the gear are formed from a resin composition of a non-reinforced type comprising (a) a polyamide resin having a carboxyl group at least at a terminal end; (b) 0.5-5 wt. % a polycarbodiimide compound, and (c) 3-15 wt. % an elastic material modified with a reactive functional group.

Gear for electric power steering device

A roller bearing cage is made of a resin and has a tapered tubular shape as a whole. In the roller bearing cage, tapered rollers are forcibly fitted to pockets while elastically deforming pillar portions at a small-diameter annular portion side. A stress alleviating portion is provided on at least an outer circumferential side of an end of the pillar portion at the small-diameter annular portion side so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut, thereby alleviating the stress occurring in the pillar portion when the tapered roller is forcibly fitted to the pocket.

Roller bearing cage and tapered roller bearing

A method of making a coated article is provided. The method includes electrostatically depositing powder onto a metallic article to be coated using an electrostatic spray gun while the metallic article is being rotated around its axis such that the powder is deposited around the entire circumference of the metallic article at least in a radially outward peripheral region having projections and depressions and that the powder deposited on top of the projections is larger in thickness than the powder deposited in other parts of the metallic article. Melting of the powder is performed by induction heating the metallic article to make a coating film adhere to the metallic article.

Coated article, manufacturing method therefor and coating apparatus

A worm wheel includes an annular metallic core portion and a resin rim portion which is fitted on an outer circumference of the core portion. The rim portion includes an annular main body portion which covers the outer circumference of the core portion and in which a toothed portion is formed on an outer circumference thereof and a pair of annular flanges which are made to extend from the main body portion in a radially inward direction X to thereby cover, respectively, outer edge portions of first and second sides of the core portion. The first annular flangeengages with a recess formed in the corresponding side of the core portion. A bottom portion of the recess includes an undercut portion in relation to a radially outward direction.

Worm wheel and electric power steering system

A resin gear for an electric power steering apparatus is provided which offers excellent mechanical strength and durability, and in which damage of teeth, does not occur even when the gear is employed in an electric power steering apparatus equipped with a high-power electric actuator. The resin gear for an electric power steering apparatus includes a worm wheel, and a gear portion thereof is formed of a resin molding material containing a thermosetting resin and polyparaphenylene-benzobisoxazole fibers (PBO fibers) as essential constituents.

Resin gear for electric power steering apparatus and electric power steering apparatus equipped with the same

A gear composed of a polymer blend or a copolymer of PA66 and PA6 which contains a part having a PA66 molecular structure and a part having a PA6 molecular structure in a weight ratio of PA66/PA6=99.9/0.1 to 95.0/5.0 is excellent in durability as well as heat resistance and dimensional stability. A speed reduction gear using the gear has a reduced size, and can be used under a higher torque without a torque increase due to dimensional change of the gear. An electric power steering apparatus using the speed reduction gear has a reduced size, and can be used for a larger automobile.

Gear, speed reduction gear using the same, and electric power steering apparatus using the same

After forming a primary powder bed (i.e., powder layer) at a toothed portion of an article, such as a gear or a spline shaft, by electrostatic powder coating process, the powder bed/layer is removed from crests of teeth in the toothed portion by a specified thickness by scraping it off while sucking up the scraped powder. Next, the electrostatic powder coating process is performed again to form a secondary powder bed/layer over the entire surface of the toothed portion. Then, the primary and secondary powder beds/layers are melted or fused by induction heating to thereby form a coating film of a substantially uniform thickness.

Method for manufacturing coated article

An electric power steering apparatus including a reduction mechanism for transmitting an output of a steering assist motor to a steering mechanism through a worm and a worm wheel , in which the worm wheel is formed by a thermosetting synthetic resin filled with a sheet of aramid fibers having a low attacking property to a counter member and an effect of improving the abrasion resistance of the synthetic resin. Even when the reduction mechanism is used in an engine room or the temperature of the reduction mechanism is raised by frictional heat with heightening power, the reduction mechanism is durable, and further the gears have excellent abrasion resistance and toughness and improved durability.

Electric power steering apparatus

The invention relates to a worm wheel for use in a reduction gear, for example, and to a machine and a method for forming the same. The worm wheel includes a tooth having a tooth crest. At least the teeth are formed by injection molding a synthetic resin. The tooth crest includes a trace formed along a parting line as a result of the injection molding process. The trace does not exist on a surface of action of the tooth. The invention is suitable for applications demanding high contact gear accuracies.

Injection molding machine for making a worm wheel

An electric steering apparatus comprises an annular tooth portion and a metal boss portion fitted in the inside of the annular tooth portion. The annular tooth portion has teeth for engaging with a worm. The annular tooth portion is made of synthetic resin material mixed with fibers having a length with an aspect ratio between 100 and 800 so that the fibers are arranged preferably in a direction crossing the direction of the torque, which is applied to the teeth, thereby to heighten a fatigue strength of the teeth and the teeth root portions.

In an electric power steering device, a driven gear of a deceleration gear mechanism for transmitting rotation of an electric actuator for generating auxiliary steering power has a gear body made of a synthetic resin material. At least the outer periphery of a metal core ring is covered by the gear body. The gear body is molded and integrated with the core ring by injecting synthetic resin material into a mold, in which the core ring is inserted. A plurality of teeth, each of which has faces which run in the direction of the axis of rotation of the driven gear, are formed on the outer periphery of the core ring so as to be arranged at intervals in a circumferential direction. The synthetic resin material that constitutes the gear body is filled in the spaces between the teeth of the core ring.

An electric power steering apparatus including a reduction mechanism for transmitting an output of a steering assist motor to a steering mechanism through a worm and a worm wheel in which the worm wheel is formed by a thermosetting synthetic resin filled with a sheet of aramid fibers having a low attacking property to a counter member and an effect of improving the abrasion resistance of the synthetic resin. Even when the reduction mechanism is used in an engine room or the temperature of the reduction mechanism is raised by frictional heat with heightening power, the reduction mechanism is durable, and further the gears have excellent abrasion resistance and toughness and improved durability.

In an electric power steering device, the rotation of an electric actuator for generating auxiliary steering power is transmitted to a vehicle wheel by way of a worm and a worm wheel. The worm wheel is molded from a synthetic resin material. The relative viscosity (VR) of the molded worm wheel is made greater than or equal to 100 and less than or equal to 300.

An electric power steering apparatus includes a worm wheel having an annular tooth portion made of synthetic resin and a boss portion made of metal. The annular tooth portion has teeth that engage with a worm, and the boss portion is fitted to the annular tooth portion. One of an inside peripheral surface of the annular tooth portion and an outside peripheral surface of the boss portion has concaves disposed on both axial ends thereof, and the other has convexes fitted into the concaves. The radial length of these concaves and convexes is 1 to 2.5 times as large as the axial length of the concaves and convexes.

Growing community of inventors

Yamatokooriyama, Japan

Takanori Kurokawa