Ntn Corporation

Nidec Corporation

Tohoku Ricoh Co., Ltd.

Nippon Steel Chemical Co., Ltd.

Tetsuya Kurimura

Yasuhiro Yamamoto

Nobuyoshi Yamashita

Toshiyuki Mizutani

Shinji Komatsubara

Isao Komori

Tatsuo Kawase

Natsuhiko Mori

Fuminori Satoji

Tetsuya Yamamoto

Masaharu Hori

Jun Hirade

Koji Yamagata

Masato Utiumi

Kiyoshi Shimizu

Yoshitaka Kabata

Masatoshi Tanigawa

Eiichi Fujita

Takehito Tamaoka

Fuyuki Ito

Ryouichi Nakajima

Katsuo Shibahara

Kimihiko Bito

Kenji Ito

Katsumi Nagano

Hidenobu Mikami

Hiroyuki Noda

Kimihiko Bitou

Yoshiharu Inazuka

Kazuyoshi Harada

Noriyuki Kadowaki

Tatsuya Hayashi

Yoshihiko Oeda

Takao Arai

Toshiaki Niwa

Makoto Endo

Tsukasa Toyoda

Yukitaka Hayakawa

Masashi Yamagou

Tadahiro Uchiyama

Mikihisa Fujiwara

Kazuhiko Koseki

Tamotsu Kodama

Provided is a slide bearing (bearing sleeve ()), comprising an oxidized green compact in which particles () of metal powder are bonded to each other by an oxide film () formed on surfaces of the particles (). The oxidized green compact has a bearing surface (A, B) configured to slide, through intermediation of a lubricating film, relative to a mating member (shaft member ()) to be supported. The bearing surface (A, B) has a large number of opening portions (), and the large number of opening portions () and inner pores () are interrupted in communication therebetween by the oxide film ().

Slide bearing

A shaft member for a fluid bearing device includes, on an outer peripheral surface thereof, two bearing surfaces (and) separated from each other in an axial direction, and a middle relief portion () formed between the bearing surfaces (and) and having a diameter smaller than a diameter of the bearing surfaces. The middle relief portion () includes a cylindrical surface portion () having a ground surface, and stepped portions () arranged on both axial sides of the cylindrical surface portion and having a diameter difference from the cylindrical surface portion.

Shaft member for fluid bearing device, manufacturing method therefor, and fluid bearing device

Dynamic pressure bearing (), including: a green compact ('), as a base material, of raw material powder including metal powder capable of forming an oxide coating; and dynamic pressure generating portions (Aand A) formed through die molding on an inner peripheral surface () forming a radial bearing gap with an outer peripheral surface () of a shaft to be supported, that is, a shaft member (). An oxide coating () is formed between particles of the metal powder by subjecting the green compact (&#x2032;) to steam treatment, and the dynamic pressure bearing () has a radial crushing strength of 150 MPa or more.

Dynamic pressure bearing and method for manufacturing same

A ratio W/Wof a circumferential width Wof each of inclined hill portions Gof a radial dynamic pressure generating portion G and a circumferential width Wof each of inclined groove portions Gis 1.2 or larger. And when an inner diameter of a bearing member is D, the circumferential width Wof each of the inclined groove portions satisfies 0.2D&#x2264;W&#x2264;0.4D.

Fluid dynamic bearing device, and bearing member and shaft member for use in same

Provided is a fluid dynamic bearing device () including a rotary body (A), a bearing member () (sleeve portion) made of a sintered metal arranged on the rotary body (A), having end surfaces (), a thrust bearing gap formed by a lower end surface () of the bearing member (), filled with lubricating oil (), and a thrust dynamic pressure generating portion (B). A dynamic pressure generating action is caused in the lubricating oil in the thrust bearing gap along with rotation of the rotary body (A) to support the rotary body (A) in one thrust direction in a non-contact manner. The bearing member () has an oil permeability of 4% or more with respect to a mass flow rate of the lubricating oil () flowing along the thrust dynamic pressure generating portion (B) during the rotation of the rotary body (A).

Fluid dynamic bearing device and motor provided with same

A sintered bearing includes a sintered metal formed by using a metal powder mixture containing copper powder and iron powder. The metal powder mixture contains 80 wt % or more of particles having an average particle diameter of less than 45 &#x3bc;m. The copper powder contains electrolytic copper powder. The electrolytic copper powder contains 40 number % or more of particles having a circularity of 0.64 or more.

Sintered bearing and method of manufacturing same

A fluid dynamic bearing device including: a bearing sleeve fixed to an inner periphery of a housing; a shaft member removably inserted along an inner periphery of the bearing sleeve; an annular member having an inner peripheral surface for defining a radial gap together with an outer peripheral surface of the shaft member; and radial bearing portions and a thrust bearing portion for supporting the shaft member. At least the radial bearing gap at each of the radial bearing portions, and a bottom gap having the thrust bearing portion received therein are filled with lubricating oil. A void section is formed in an interior space of the housing. Assuming that drepresents a gap width of the radial bearing gap and drepresents a gap width of the radial gap, a relationship of 30d&#x2266;d&#x2266;250dis satisfied.

Fluid dynamic bearing device and motor with same

A fluid dynamic bearing device (), including: a bearing member () on a rotary side; a housing () on a stationary side; a sealing member (); a radial bearing gap to be formed between an outer peripheral surface () of the bearing member () and an inner peripheral surface () of the housing (); and a thrust bearing gap to be formed between a lower end surface () of the bearing member () and an inner bottom surface () of the housing (). The radial bearing gap and the thrust bearing gap are filled with lubricating oil (). An axial gap () containing air is formed between an upper end surface () of the bearing member () and a lower end surface () of the sealing member (), which faces the upper end surface () of the bearing member ().

A fluid dynamic bearing device () includes: a shaft member (); a housing () as an outer member which is arranged on a radially outer side of the shaft member () and is opened at both ends; a radial bearing gap which is formed on a radially inner side of the housing () and faces an outer peripheral surface of the shaft member (); and a lid member () closing an opening on one end side of the housing (), wherein the lid member () is fitted to an outer peripheral surface of the housing () with a fastening allowance which does not affect accuracy of a surface defining an outer diameter dimension of the radial bearing gap so that the housing () and the lid member () are bonded and fixed to each other.

Fluid dynamic bearing device

Providing a fluid dynamic bearing device, wherein the outer member comprises a member formed by a pressing process on a plate member, the radial bearing surface and at least the one of the thrust bearing surfaces of the outer member being formed by the pressing process, and wherein at least a part of the inner member, which forms the radial bearing surface and the thrust bearing surfaces of the inner member, is made of a sintered metal.

Fluid dynamic bearing device and assembly method for same

An inner peripheral surface and a lower end surface of a bearing sleeve made of a sintered metal are each formed into a smooth cylindrical surface or a flat surface that does not have a dynamic pressure generating portion. Thus, a step of forming the dynamic pressure generating portion can be omitted from a manufacturing step of the bearing sleeve, and cost of dies can be markedly reduced. Further, the inner peripheral surface of the bearing sleeve is formed into the smooth cylindrical surface, and hence a radial dynamic pressure generating portion is formed on an outer peripheral surface of a shaft member. However, the outer peripheral surface of the shaft portion is accessible to tools, and hence the radial dynamic pressure generating portion can be formed easily with high accuracy. As a result, accuracy of a radial bearing gap is enhanced so that a bearing rigidity is enhanced.

A fluid dynamic bearing devicehas a bearing sleeve, a shaft memberwhich is inserted in the inner periphery of the bearing sleeve, a housingwhich is formed by pressing, has the bearing sleevepress-fitted in the inner periphery thereof, and has a stepped sectionwhich engages with the end surface of the bearing sleeve and is located ahead in the direction of press-fitting of the bearing sleeve, a thrust receiverwhich is in contact with and supports an end of the shaft member, and a seal portionwhich prevents oil from leaking from the inside of the housing. A dynamic pressure generating groovefor generating fluid dynamic pressure in a radial bearing gap between the outer peripheral surface of the shaft memberand the inner peripheral surface of the bearing sleeveis formed in the inner peripheral surface of the bearing sleeve

A housing for a fluid lubrication bearing apparatus is produced. The housing has a cylindrical shape whose inner periphery having a fixing face to which an outer circumferential surface of a bearing sleeve is to be fixed. The method includes providing a forging mold having a groove molding portion extending parallel to a direction of a stroke of said mold and a face molding portion having a convex cylindrical shape on an outer periphery of the forging mold for forming the fixing face of the housing. The method further includes forming the housing with the forging mold, while forging circulation grooves and the fixing face simultaneously on the inner periphery of the housing with the groove molding portion and the face molding portion of the forging mold.

Method for producing a housing for a fluid bearing apparatus

A fluid bearing apparatus includes a housingwhich has a cylindrical shape having a fixing facefor fixing the outer circumferential surfaceof a bearing sleeve, and axial circulation groovesfor bringing both end facesof the bearing sleeveinto circulation on the inner periphery by forging. A groove molding portionis provided on the outer circumference of a rodwhich serves as a forming mold for the inner periphery of the housing, and the circulation groovesare formed by forging with this groove molding portion. Moreover, after a sealing faceand a cylindrical outer circumferential surfaceprovided on the outer periphery of the housingare formed by forging, an inner circumferential surfaceis formed by forging.

Fluid bearing apparatus

A fluid dynamic bearing device includes: a shaft member; a bearing sleeve which forms a radial bearing gap between the bearing sleeve and an outer peripheral surface of the shaft member; a housing which accommodates the bearing sleeve and is opened at both ends; and a lid member which closes an opening on one end side of the housing and forms thrust bearing portions. The housing is an injection-molded product into which the bearing sleeve is inserted, and the housing has another end with which a seal portion forming a seal space is integrally formed. The lid member is fitted with the outer peripheral surface of the housing by loose fitting so that the lid member and the housing are bonded and fixed to each other.

Growing community of inventors

Kuwana, Japan

Tetsuya Kurimura