Ntn Corporation

Daiwa Steel Corporation

Katsutoshi Muramatsu

Yasutake Hayakawa

Norio Misaki

Yutaka Tanaka

Kenji Ito

Daichi Ito

Masaaki Honda

Hikaru Ishida

Hiroyuki Inoue

Nobuyuki Ninoyu

Masayuki Nozaki

Hiroaki Suzuki

Makoto Ishihara

Shozo Goto

Kouichi Kiyohara

Toshiaki Kaneko

Yoshimi Nishihara

An inspection method of a rolling element includes the steps of: projecting an X-ray from a light source to a rolling element, detecting the X-ray passing through the rolling element by a detector, calculating data of the detected X-ray to form an image, and detecting a defect in the rolling element based on the image. At the step of projecting an X-ray, the light source rotates relatively around the rolling element while the X-ray is projected to an entire region of the rolling element facing the light source. At the step of forming an image, data of the X-ray for one circuit around the rolling element is calculated to generate the image.

Rolling element inspection method, rolling element manufacturing method, and rolling element

A green ball grinding method includes the step of supplying a green ball between a first surface of a first member and a second surface of a second member constituting a grinding apparatus, and the step of grinding the green ball between the first surface and the second surface while the green ball rotates around its own axis and in orbital motion. In the step of grinding the green ball, the step of causing the green ball grinding to proceed while applying load between the green ball and each of the first surface and the second surface, and the step of modifying the rotation axis of the green ball by reducing the load lower than in the step of causing the green ball grinding to proceed are executed alternately.

Green ball grinding method, ceramic sphere fabrication method, and grinding apparatus

A deep-grooved ball bearing including a rolling contact member formed of a sintered &#x3b2;-sialon inexpensive and capable of reliably ensuring sufficient durability includes an outer ring and an inner ring, and a plurality of balls arranged in contact with the outer ring and the inner ring on an annular raceway. The ball is configured of a sintered body that contains as a main component a &#x3b2;-sialon represented by a compositional formula of SiAlONand satisfying 0.1&#x2266;z&#x2266;3.5 and has a remainder formed of an impurity.

Rolling bearing, hub unit, rolling contact member, universal joint, torque transmission member for universal joint, and method of producing the same

An outer ring, an inner ring and a ball that are a rolling contact member formed of sintered &#x3b2; sialon inexpensive and capable of reliably ensuring sufficient durability, is constituted of a sintered body containing &#x3b2; sialon as a main component and having a remainder formed of an impurity, and the outer ring, the inner ring and the ball have raceway/rolling contact surfaces, i.e., an outer ring raceway surface, an inner ring raceway surface and a ball rolling contact surface included in a portion having an outer ring high density layer, an inner ring high density layer and a ball high density layer higher in density than an inner portion.

Rolling contact member, rolling bearing, and method of producing rolling contact member

A spherical body polishing apparatus capable of reducing polishing costs includes a rotating disk having a rotating disk polishing surface and a fixed disk having a fixed disk polishing surface opposed to the rotating disk polishing surface. The rotating disk polishing surface is capable of relative rotation while keeping being opposed to the fixed disk polishing surface. The rotating disk polishing surface has a groove portion formed therein and extending circumferentially along the rotation. The rotating disk having the groove portion therein includes an abrasive grain layer having a higher hardness than that of a material ball which is a spherical body and a holding layer formed on the abrasive grain layer and having a lower hardness than that of the abrasive grain layer. The groove portion is formed to penetrate the holding layer in a depth direction and to reach the abrasive grain layer.

Spherical body polishing apparatus, method for polishing spherical body and method for manufacturing spherical member

Rolling contact member and rolling bearing

Each of an outer ring, an inner ring, and a ball is a rolling contact member formed of a &#x3b2;-sialon sintered body inexpensive, capable of reliably ensuring sufficient durability, and capable of being used in an application where an imposed load is changed abruptly. The sintered body contains as a main component &#x3b2;-sialon represented by a compositional formula of SiAlONand satisfying 0.1&#x2266;z&#x2266;3.5, and has a remainder formed of an impurity. The rolling contact member has a Young's modulus of 180 GPa or greater but 270 GPa or smaller.

A method for recycling steelmaking dusts has a granulating step of mixing steelmaking dusts, containing as a principal component iron and oxides thereof produced during the steelmaking in a melting furnace, with a powder containing carbon as a principal component and granulating the resultant mixture to provide mixed granules, a water impregnating step of immersing the mixed granules in a water to allow them to be impregnated with the water, a solidifying step of molding the water impregnated, mixed granules under pressure within a mold assembly to provide a solid body of the steelmaking dusts, a step of transporting the solid body of the steelmaking dusts as a raw material to be charged into the melting furnace, an enhancing step of increasing the concentration of zinc in the dusts, and a dezincing step of dezincing the dusts during a period from acquisition of the steelmaking dusts out of the melting furnace to the solidifying step.

Method for recycling steelmaking dust

A solidified product (B) is produced by charging a dust () generated in a steel making process and containing iron and an oxide thereof as a principal component into a mold () and by subjecting it to a pressure molding. A raw material charged to the mold is a mixed granulated product () prepared by mixing the dust and a powder containing carbon as a principal component and by granulating the resultant mixture.

Solidification product of dust generated during steel making and method for production thereof

Silicon balls of single crystal silicon for use in semiconductir circuit substrates or the like, which have been lapped to satisfy necessary requirements and a method of making the same. The silicon ball of single crystal silicon is a lapped ball of single crystal silicon having a sphericity of not greater than 0.08 &mgr;m and also having a residue stress layer of not greater than 5 &mgr;m in a depth from a processing surface thereof on one side in negative and positive directions. The method of making the silicon balls makes use of a pair of lapping tables and supported in face-to-face relation with each other. One or both of the lapping tables and is prepared from finely divided abrasive particles hardened by the use of a resinous bonding material. Workpieces W of single crystal silicon are sandwiched between the lapping tables and and are lapped to provide the lapped balls.

Balls of single crystal silicon and method of making the same

A ceramics material for a sliding member used in the water or brought into contact with water is proposed. It is low in frictional resistance and high in wear resistance and shows a long life when used in such a condition. Also, a disk valve assembly is proposed which has a valve body and a valve seat having sliding surfaces that are high in sliding properties. By sliding the valve body on the valve seat having valve holes, the valve holes can be opened and closed. One of the valve seat and the valve body is made of a self-lubricating ceramics material comprising of an oxide ceramic as a main component, and at least one anti-friction agent selected from the group made up of iron, nickel, cobalt and their oxides, nitrides and carbides. The other of the valve seat and the valve body is made of an aluminum oxide ceramics material and has a larger slide contact area than the one of the valve seat and the valve body.

Growing community of inventors

Kuwana, Japan

Katsutoshi Muramatsu