Ntn Corporation

National Institute of Advanced Industrial Science and Technology

Yosuke Taguchi

Hidenobu Mikami

Takayuki Kawamura

Kouya Oohira

Masaki Nakanishi

Setsuo Nakao

The present invention provides a grease composition or a lubricating oil composition which is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface of a rolling bearing, is excellent in durability in a high temperature and speed operation, and can be used for a long time. A grease-packed bearing () has an inner ring (), an outer ring (), and a plurality of rolling elements (). A sealing member () for sealing a grease composition () is provided at openings () and () disposed at both axial ends of the inner ring () and the outer ring (). The grease composition () includes a base grease composed of a base oil and a thickener and an additive added to the base grease. The additive contains at least one compound selected from among plant-derived polyphenolic compounds and compounds formed by decomposition thereof. The above-described compounds include tannin, gallic acid, ellagic acid, chlorogenic acid, caffeic acid, curcumin, quercetin, and quinic acid.

Grease composition, grease-packed bearing, universal joint for propeller shaft, lubricating oil composition, and oil-impregnated sintered bearing

The present invention provides a film formation method capable of forming a favorable amorphous carbon film under a low vacuum by using a bipolar-type PBII apparatus and the amorphous carbon film to be produced by the film formation method. The film formation method is carried out to form the amorphous carbon film under a low vacuum (1000 to 30000 Pa) by using a power source for the bipolar-type PBII apparatus. There are provided inside a chamber () a power source side electrode () connected to a power source () for the PBII apparatus and a grounding side electrode () opposed to the power source side electrode (). A base material () is disposed on one of the power source side electrode () and the grounding side electrode (). Plasma of a noble gas and that of a hydrocarbon-based gas are generated between the base material () and the electrode where the base material () is not disposed to form the amorphous carbon film on a surface of the base material ().

Amorphous carbon film and method for forming same

A rolling bearing which has excellent performance at high-temperatures and has high-speed durability and quietness, is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface thereof, and has a low environmental load. The rolling bearing () is constructed of an inner ring () having a rolling surface on its peripheral surface, an outer ring () having a rolling surface on its inner peripheral surface, a plurality of rolling elements () disposed between both rolling surfaces, and a cage () retaining the rolling elements (). The inner ring (), the outer ring (), the rolling elements () or the cage () are metal-made bearing members. Film-coating treatment is conducted on a sliding surface or a rolling surface of at least one of these metallic bearing members with plant-derived polyvalent alcohol compounds such as curcumin, quercetin, chlorogenic acid or the like.

Rolling bearing

A rolling bearing () having an inner ring (); an outer ring (); a plurality of rolling elements () interposed between the inner ring () and the outer ring (); a retainer () retaining the rolling elements (); and a seal () provided at an open portion, of the inner ring () and the outer ring (), which is disposed at both axial ends thereof. The rolling bearing () is lubricated with a grease () enclosed in a space, inside the bearing, which is constructed of the inner ring (), the outer ring (), the retainer (), and the seal ().

Growing community of inventors

Mie, Japan

Yosuke Taguchi