Ntn Corporation

Kyodo Yushi Co., Ltd.

Mitsunari Asao

Hidenobu Mikami

Takayuki Kawamura

Masaki Egami

Toshiaki Endo

Eiichirou Shimazu

Takahiro Koremoto

Osamu Hirano

Yuji Oonuki

Kunio Takemura

The present invention provides a grease composition which contains a small amount (not more than 0.06 wt %) of molybdenum and yet is capable of achieving an excellent low friction property when mechanical parts in which the grease composition has been packed are operated under a severe sliding condition in which they are subjected to a high speed and a high contact pressure. The present invention also provides a bearing, a universal joint, and a linear motion device in which the grease composition of the present invention is packed. A grease composition () is packed inside a grease-packed bearing () in such a way that the grease composition () is applied to at least the circumference of each rolling element (). The grease composition () contains base oil, a thickener, and an additive. The additive includes molybdenum dithiocarbamate and sodium dithiocarbamate.

Grease composition, grease-packed bearing, universal joint and linear motion device

The present invention relates to a nitrite free grease composition having an oil base, a thickener, and several additives, including a metal salt of dibasic acid. The metal salt having sub-groups that can either be aliphatic or aromatic hydrocarbons. Additionally, the present invention relates to a grease-sealed bearing with a longer lifetime and excellent rust preventative properties.

Grease composition having a base oil, a thickener and an additive including a metal salt of dibasic acid

A lubricating grease is provided which is excellent in durability at high temperatures, inhibits the reaction between fluorine and steel and has a long life and a rolling bearing in which the lubricating grease is enclosed. The lubricating grease contains perfluoropolyether oil as a base oil thereof and fluorocarbon resin powder as a thickener thereof, a diurea compound having an &#x2014;NH&#x2014; bond in the molecular structure thereof, an organic-acid metal salt or a bismuth-containing compound such as bismuth sulfate. The rolling bearing has an inner ring and an outer ring disposed concentrically with each other, a plurality of rolling elements interposed between the inner ring and the outer ring, and a retainer dividedly holding the rolling elements.

Lubricating grease and lubricating grease-enclosed roller bearing

The present invention provides a grease composition capable of securely preventing generation of a low-temperature abnormal noise when it is cold and a grease-enclosed bearing. A grease composition comprises a base oil and a thickener, wherein the base oil has a pour point not more than &#x2212;50&#xb0; C. and a kinematic viscosity not less than 15 mm/s at 40&#xb0; C. The base oil is at least one oil selected from a PAO oil and a perfluoro ether oil. The thickener is at least one substance selected from a urea compound and a fluororesin. A mixing consistency of the grease composition is in the range of 250 to 350. A grease-enclosed bearing has an inner ring, an outer ring, rolling elements interposed between the inner ring and the outer ring, and a grease composition enclosed on a periphery of the rolling elements. The grease-enclosed bearing is used for an automotive electric auxiliary machine.

Grease composition and grease-enclosed bearing

A rolling bearing, for application in electric auxiliaries for a car, durable owing to high resistance to high temperatures and capable of restraining noises from being generated at low temperatures; and lubricant grease, for low and high temperature application, which can be sealed in the rolling bearing. The lubricant grease includes 100 parts by weight of a mixture of fluorine-containing lubricant grease containing perfluoropolyether oil as a base oil thereof and fluorocarbon resin powder as a thickening agent thereof and urea-containing lubricant grease containing polyester oil as a base oil thereof and a urea compound as a thickening agent thereof; and 3 to 30 parts by weight of polyolefin oil added to the mixed grease. The polyolefin oil has a pour point of not more than &#x2212;50&#xb0; C. and a kinematic viscosity of 10 to 70 mm/s at 40&#xb0; C.

Lubricant grease for low and high temperature application and rolling bearing

Disclosed is a grease that provides a prolonged lubricating lifetime to applied portions for use at high temperature, and a grease sealed bearing in which the bearing is sealed with this grease. This grease comprises a base oil, a thickener, and an amide-based wax. The amide-based wax is contained in an amount of 0.5 to 10% by weight based on the total amount of the grease, has a melting point of 80&#xb0; C. or more, and an antioxidative ability to the base oil. The base oil is at least one base oil selected from the group consisting of an ether-based oil, an ester-based oil and a synthetic hydrocarbon oil, and has kinematic viscosity of 20 to 150 mm/s at 40&#xb0; C. The thickener is an urea-based thickener, and is contained in an amount of 5 to 30% by weight based on the total amount of the grease.

Grease and grease sealed bearing

Disclosed is a grease sealed bearing for automobile that has the high temperature resistance as well as shear stability, and prevents the noise at low temperature as well as the brittle flaking under high speed rotation and high load. The grease comprises a base oil containing a synthesized hydrocarbon oil and one or more ester oils at a weight ratio of 0.1 to 0.49:0.9 to 0.51; 5 to 30% by weight of a urea based thickener, and 0.1 to 10% by weight of dithiozinc phosphate based on the whole grease. The grease sealed bearing for automobile is obtained by sealing a bearing used in a device driven by an automobile engine with the grease.

Grease sealed bearing for automobile

A solid lubricant for bearings which is less likely to be washed away by water or liquid mud coming into bearings, and which can restrain the development of rust even in a harsh environment where high-concentration salt water comes into the bearings. A rust preventive in the form of a sulfonate or a fatty polyhydric alcohol partial ester is added to a composition made up of 5-97% by weight of a lubricating grease, 93-1% by weight of an ultra-high-molecular-weight polyolefin powder, and 1-50% by weight of oil exudation inhibitor, and mixed together. The mixture is then heated to a temperature higher than the gel point of the ultra-high-molecular-weight polyolefin and preferably lower than the dropping point of the lubricating grease and molded into the solid lubricant for bearings.

Solid lubricant for bearings comprising a mixture containing a

A lubricative composition which can retain lubricating oil or grease without degrading it, which is heat-resistant and mechanically strong, and can be used continuously for a much longer time than conventional ones without the possibility of shortage of lubricant supply. It includes a first component, which is a modified silicone oil having reactive organic groups, a second component, which is a curing agent having organic groups that react with the reactive organic groups, and a third component, which is a lubricating oil or grease. The third component is retained in a three-dimensionally reticulated structure of silicone formed by polymerizing the first and second components in the third component. The third component has no compatibility with either the first or second components. The lubricating oil or grease retained in the lubricative composition can ooze out through the pores that communicate with each other onto the surface of the lubricative composition, so that the composition will exhibit lubricating properties stably for a long period of time. By adding a high-viscosity synthetic hydrocarbon oil to the base oil of the lubricating oil or grease, it is possible to positively prevent separation of oil during hardening.

Lubricative composition

A grease composition sealed in a rolling contact bearing contains a base oil in the form of a mixture of an alkyldiphenylether oil and a poly-.alpha.-olefin oil. The weight ratio of the former to the latter is between 20:80 and 80:20. 5-40% by weight of thickening agent which is at least one of an aromatic diurea compound and an aromatic urea-urethane compound is added to the base oil. Further, a passivation oxidizing agent and an organic sulfonate are added.

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Kuwana, Japan

Mitsunari Asao