Ntn Corporation

Hajime Asada

Takuya Ishii

Kei Hattori

Tatsuro Sugiyama

Yoshinori Ito

Natsuhiko Mori

Hiroyuki Noda

Mika Kohara

Masato Shimoda

Takahiro Okuno

Hiroshi Akai

A sliding member () includes an iron and steel-based sintered compact containing chromium, molybdenum, and carbon and having a content of chromium, of 5 mass % or less. The sliding member () includes: a compound layer () which has a sliding surface () and is formed mainly of an iron and steel nitride; and a diffusion layer () which is adjacent to the compound layer () and has an iron and steel structure into which nitrogen and carbon diffuse. The concentrations of carbon and nitrogen in the diffusion layer () are gradually reduced with increasing depth from the sliding surface ().

Sliding member and method for producing same

An internal gear pump integrally provided with a plain bearing requiring fewer machining steps, allowing inexpensive manufacture, and offering a highly stable seizing property. The internal gear pump has a trochoid (), in which an inner rotor () having a plurality of outer teeth is eccentrically and rotatably accommodated in an outer rotor () having a plurality of inner teeth, the outer teeth meshing with the inner teeth, and in which a suction-side chamber for suctioning liquid and a discharge-side chamber for discharging the liquid that has been suctioned into the suction-side chamber are formed between the inner teeth and outer teeth; a drive shaft () fixed to the inner rotor (); a casing () in which is formed a recess () for accommodating the trochoid (); and a cover () for closing off the recess () of the casing ().

Internal gear pump

Provided is an internal gear pump requiring fewer machining steps, allowing inexpensive manufacture, and offering high safety from the standpoint of function. The internal gear pumpcomprises: a trochoidin which an inner rotorhaving a plurality of outer teeth is eccentrically and rotatably accommodated in an outer rotorhaving a plurality of inner teeth, the outer teeth meshing with the inner teeth, and in which a suction-side chamber for suctioning liquid and a discharge-side chamber for discharging liquid that has been suctioned into the suction-side chamber are formed in between the inner teeth and outer teeth; a casingin which is formed a recessfor accommodating the trochoid; and a coverfor closing off the recessof the casing. At least some of the casingis a body injection-molded from a resin composition. The invention also comprises a groovein a portion of the recessof the casingin which the outer periphery is sealed, with a sealing ringinstalled therein, and bushingsmade from sintered metal that are provided integrally during injection molding in bolt fixing hole portions.

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.

Growing community of inventors

Mie, Japan

Hajime Asada