Eneos Corporation

Jtekt Corporation

Honda Motor Co., Ltd.

Jx Nippon Oil Energy Corporation

Jxtg Nippon Oil & Energy Corporation

Yusuke Ayame

Kiyomi Sakamoto

Kazumi Sakai

Go Tatsumi

Kazunori Miyake

Yasuo Suzuki

Hisayuki Wada

Yuji Shitara

Takeshi Tsuda

Koji Yoshizaki

Yurie Hagino

Katsuhito Kusakai

Toru Izumi

Kazuya Matsuoka

There is provided a grease composition for improving the chemical stability of the grease composition and increasing the fatigue life of a member in which the grease composition is used. The problems can be solved by a grease composition including a poly-α-olefin; a urea-based thickener; molybdenum dithiophosphate; and barium sulfonate, wherein a difference between an SP value of the urea-based thickener and an SP value of the poly-α-olefin is 3.5 or less.

Grease composition and rolling bearing

A grease composition including: a base oil; a thickener; a zinc sulfonate; a polysulfide; an overbased calcium sulfonate; and triphenyl phosphite, in which a proportion of the zinc sulfonate with respect to a total mass of the base oil and the thickener is 0.030 mass % to 0.045 mass % in terms of a zinc content, a proportion of the polysulfide with respect to the total mass of the base oil and the thickener is 0.16 mass % to 0.24 mass % in terms of a sulfur content, a proportion of the overbased calcium sulfonate with respect to the total mass of the base oil and the thickener is 0.010 mass % to 0.015 mass % in terms of a calcium content, and a proportion of the triphenyl phosphite with respect to the total mass of the base oil and the thickener is 0.24 mass % to 0.36 mass %.

Grease composition, and rolling bearing

Examples of the ester oil include diester oils such as dibutyl sebacate, dioctyl sebacate, di-2-ethylhexyl sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl phthalate, and methyl acetyl ricinolate; aromatic ester oils such as trioctyl trimellitate, tridecyl trimellitate, and tetraoctyl pyromellitate; polyol ester oils such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol pelargonate; carbonate oil; complex ester oil which is an oligoester of polyhydric alcohol and mixed fatty acid including dibasic acid and monobasic acid; etc.

A grease composition for a constant-velocity joint includes a mineral oil, a thickener, a molybdenum dithiocarbamate, a potassium borate hydrate, and a zinc dialkyldithiophosphate, wherein a content of the molybdenum dithiocarbamate is 1.2% by mass or more and 8% by mass or less, a content of the zinc dialkyldithiophosphate is 0.3% by mass or more and 2.0% by mass or less, and a content of the potassium borate hydrate is 0.28% by mass or more and 1.9% by mass or less, and wherein a mass ratio of the content of the molybdenum dithiocarbamate to the content of the potassium borate hydrate (molybdenum dithiocarbamate/potassium borate hydrate) is 2 or more and 13 or less, and a mass ratio of the content of the zinc dialkyldithiophosphate to the content of the potassium borate hydrate (zinc dialkyldithiophosphate/potassium borate hydrate) is 0.5 or more and 3.6 or less.

Grease composition for a constant-velocity joint

Growing community of inventors

Tokyo, Japan

Yusuke Ayame