Ntn Corporation

Kyb Corporation

Ntn Toyo Bearing Co., Ltd.

Nin Corporation

Kenji Hibi

Yasuhiro Yamamoto

Tetsuya Yamamoto

Isao Komori

Masaharu Hori

Masaaki Toda

Toshihide Goto

Kenji Ito

Kazuo Okamura

Kei Kimata

Yoshinobu Akamatsu

Fuyuki Ito

Koji Kawamura

Masatsugu Mori

Mitsuo Sasabe

Yasuhiro Shimizu

Hideki Yamada

Hiroshi Niwa

Kazuyuki Kimishima

Yukitaka Hayakawa

Toshihiko Matsushima

Makoto Arano

Morikatu Kotani

Yoshimi Ohta

A valve structure of a shock absorber includes a piston to which a first communication passage and a second communication passage are provided, and a load application member that applies an initial load to a first leaf valve. The initial load is applied to the first leaf valve within a range between the inside in the radial direction from a first seat part and the outside in the radial direction from an abutting part of the piston, the first seat part being positioned on the outside in the radial direction of the first communication passage.

Valve structure of shock absorber

A sintered metal bearing is obtained by compression-molding of a raw-material powder containing at least a Cu powder, an SUS powder, and a pure Fe powder and thereafter sintering a compression-molded body at a predetermined temperature.

Sintered metallic bearing and fluid dynamic bearing device equipped with the bearing

A fluid dynamic bearing device which can exhibit high bearing performance is provided at low costs by forming a highly accurate bearing gap. At least a region in the outer circumferential surface of a shaft which faces the radial bearing gap is constituted of an electroformed part, and the region of the shaft excluding the electroformed part is constituted of a resin portion.

Fluid dynamic bearing device

A gap width out of the radial bearing gap is axially differed; a narrow width part which has a relatively smaller gap width in the radial bearing gap is arranged on the side relatively closer to a barycentric position of the rotating body, and a wide width part which has a relatively larger gap width in the radial bearing gap is arranged on a side relatively distant from the barycentric position of the rotating body; and a region facing at least the radial bearing gap of the bearing member is formed to an electroformed part made of deposited metal.

Fine particles () are retained by an electroformed portion () in a dispersed state, and the fine particles () exposed from an outer peripheral surface () of the electroformed portion () are molten so as to form micro projections () integrated with a resin portion (). The micro projections () enters into fine-particle traces () formed in the electroformed portion () to exert an anchor effect, to thereby increase a fixation force between the resin portion () and the electroformed portion ().

Electroformed bearing and method of manufacturing same

An inner periphery of a molded part having a step from an inner periphery of an electroformed part is molded to a nonconductive coating which covers the surface of a master. When the nonconductive coating is removed, a radial clearance having a diameter greater than that of a bearing clearance is created between the inner periphery of the molded part, which is exposed to the interior, and an outer periphery of a shaft member. A bearing member which forms the bearing and radial clearance with the shaft member is manufactured by performing electroforming on the master with the nonconductive coating formed on part of the surface of the master, thereby forming the electroformed part; then injection molding the bearing member with the electroformed part and the nonconductive coating on the surface of the master inserted into a cavity; and then removing the nonconductive coating from the bearing member.

Bearing member and method for manufacturing the same, and bearing unit having bearing member and method for manufacturing the same

A shaft member for a fluid dynamic bearing device that has a recess to cause a dynamic pressure effect of a fluid in a bearing clearance, which is formed on it by rolling, and where a surface layer portion of the recess and a surface layer portion of a surrounding region of the recess has a nitride layer, and where nitrogen is diffused and penetrated in a material of the shaft member that is formed by nitriding after the rolling.

Shaft member for fluid dynamic bearing device

A fluid dynamic bearing device includes a bearing sleeve including a radial bearing surface, a shaft member to be inserted to an inner circumference of the bearing member, and a radial bearing part for non-contact supporting the shaft member in a radial direction by a dynamic pressure action of a fluid generated in a radial bearing gap between the radial bearing surface of the bearing member and an outer circumferential surface of the shaft member. Additionally, a plurality of bearing sleeves are axially arranged, and each bearing sleeve is formed having different axial length with respect to one another.

Provided is a shaft member for a fluid dynamic bearing device, which is excellent in wear resistance and which can exert a high dynamic pressure effect. A shaft material () is rolled to form a recess () for causing a dynamic pressure effect of a lubricating oil in a radial bearing clearance (). In this case, in a surface layer portion () of the recess () to be formed in an outer peripheral surface () of the shaft material (), a first hardened layer () is formed by rolling. At the same time, also in a surface layer portion () of a surrounding region () of the recess (), a first hardened layer () is formed by rolling at a partial region thereof. After the recess () is formed by the rolling, barreling is applied to the shaft material (). As a result, an outermost surface layer portion of the surface layer portion () is formed with a second hardened layer () by the barreling. A hardness of the second hardened layer () formed in the surrounding region () is higher by 50 Hv or more and 200 Hv or less than that of the first hardened layer () formed in the recess ().

A sliding bearing includes a metal part formed by electroforming on an inner periphery of the sliding bearing and an oil feeding mechanism for supplying oil to the bearing gap. As a result, oil retained by the oil feeding mechanism is supplied to the bearing gap, so the lubricity between the bearing and the shaft member is improved by an oil film formed in the bearing gap. This makes it possible to avoid the generation of noise due to defective lubrication and wear of members due to the contact sliding between the bearing and the shaft member.

Bearing device with sliding bearing

A spindle unit which can offset any displacement of the spindle due to thermal expansion and which can adjust the preload on the bearings according to the revolving speed of the spindle. Between the outer casing and the spindle are provided a high-rigidity elastic member and a pressure chamber connected to an oil pressure control valve. A displacement sensor provided at the end of the spindle and a tachometer are connected to the pressure control valve. As the revolving speed of the spindle increases, oil pressure is introduced into the pressure chamber to reduce the preload. By reducing the preload, the spindle moves axially, thus offsetting its displacement due to thermal expansion.

Spindle unit

A rolling contact bearing assembly comprises an inner race member adapted to be mounted on a rotatable element and including a spacer disposed axially adjacent the inner race. This inner race member is formed with a lubricant reservoir for accommodating a lubricant and a lubricant flow passage communicating the reservoir with a space defined between the inner and outer race, in which space rolling elements are accommodated. At least a portion of said lubricant flow passage is defined by minute interstices which are formed by surface roughness left by surface roughening at an interface between mutual contact faces of a plurality of component parts forming the inner race member.

Rolling contact bearing assembly

A machine part having a rolling or sliding surface formed with a plurality of minute recesses at random with the SK value less than zero in both the longitudinal and circumferential directions, and the area ratio of the recesses to the whole rolling surface being 10-40 percent.

Machine parts having minute random recesses

A roller element for use in a roller bearing having a surface formed with minute recesses at random so that the ratio RMS(L)/RMS(C) will be not more than 0.8 wherein RMS(L) is the roughness mean square value in the longitudinal direction and RMS(C) is the roughness mean square value in the circumferential direction and so that the SK value is not more than -0.2 in both the longitudinal and circumferential directions.

Growing community of inventors

Kuwana, Japan

Kenji Hibi