Ntn Corporation

Takahiro Okuno

Yoshinori Ito

Eiichirou Shimazu

Sunao Shimizu

Tatsuro Sugiyama

Natsuhiko Mori

Kouya Oohira

Hiroyuki Noda

Mitsuo Kawamura

Mika Kohara

Eiichiro Shimazu

Hajime Asada

Yasutake Hayakawa

Naoki Yashiro

Ryuichi Sakamoto

Junichi Ooshimo

Provided is a sintered bearing that is capable of reducing cost through reduction in usage amount of copper, excellent in initial running-in characteristics and quietness, and is high in durability. Raw material powders including iron powder, flat copper powder, low-melting point metal powder, and graphite are loaded into a mold, and a green compact is formed under a state in which the flat copper powder is caused to adhere onto a molding surface. Subsequently, sintering is carried out without causing iron in the green compact to react with carbon so that an iron structure is formed of a ferrite phase. In this manner, a sintered bearing () including a base part (S) including copper at a uniform content, and a surface layer (S) covering a surface of the base part (S) and including copper at a larger content than the base part (S) can be obtained.

Sintered bearing and method for manufacturing same

A sintered compact having a density of 7.5 g/cmor more is formed by mixed powder. The mixed powder is obtained by mixing graphite powder having an average particle diameter of 8 &#x3bc;m or less and diffusion alloyed steel powder. The ratio of the graphite powder is from 0.05 wt % to 0.35 wt % with respect to 100 wt % of the diffusion alloyed steel powder. Or, the mixed powder is obtained by mixing the graphite powder and completely alloyed steel powder. The ratio of the graphite powder is from 0.15 wt % to 0.35 wt % with respect to 100 wt % of the completely alloyed steel powder.

Sintered machine part and method of manufacturing the same

A cage is made of a magnesium alloy such as AZ91D, and is molded by means of injection molding. In this cage, a confluence region is brought away to outside the cage during the injection molding. The confluence region is a region including a void formed by merging of flows of the magnesium alloy. When observing a cross sectional surface of the cage, a ratio of an &#x3b1; phase having a grain size of 20 &#x3bc;m or greater is less than 15% in the magnesium alloy constituting the cage.

Cage and rolling bearing

A constant-velocity universal joint includes an outer joint member; an inner joint member arranged in an inside of the outer joint member; and torque transmitting members. At least one of the outer joint member and the inner joint member comprises track grooves that are engaged with rolling surfaces of the torque transmitting members. At least one of the components of the constant-velocity universal joint is formed of a metal sintered compact. The metal sintered compact has a relative density of 80% or more and less than 100%. The metal sintered compact comprises a hardened layer formed on a surface thereof through heat treatment. Among the components each formed of the metal sintered compact, a component having a ring shape is subjected to a cold rolling process.

Constant velocity universal joint

Growing community of inventors

Mie, Japan

Takahiro Okuno