A grease composition includes a base oil, a thickener, and an additive. The base oil contains a synthetic oil. The thickener contains a compound having a urea group. The additive contains a phosphoric compound, a calcium-based compound, and a hydrocarbon-based wax. A hub unit includes the grease composition enclosed therein.

A grease composition includes a base oil, a thickener, and an additive. The base oil contains a synthetic oil. The thickener contains a compound having a urea group. The additive contains a phosphoric compound, a calcium-based compound, and a hydrocarbon-based wax. A hub unit includes the grease composition enclosed therein.

The invention provides a grease composition for a ball joint which has a low friction coefficient under a load from normal temperatures to high temperatures, a small difference between static friction and dynamic friction, and little change in the friction coefficient even after repeated operation. TO this end, the invention provides a grease composition for a ball joint comprising: (i) a polyisoprene rubber and/or (ii) a polyisoprene rubber viscous material; a specific aliphatic amide and/or a specific aliphatic bisamide; and a specific urea compound.

An environmentally acceptable lubricating grease, comprising: a) 50 wt % to 90 wt % of a biodegradable base oil comprising a biodegradable ester as base oil; b) 3 wt % to 25 wt % of a thickener selected from b1) 3 wt % to 12 wt % biodegradable calcium soap, b2) 3 wt % to 25 wt % bentonites, b3) and mixtures thereof; c) 4 wt % to 40 wt % additives, comprising c1) 1 wt % to 12 wt % fumed silicon dioxide and/or polytetrafluoroethylene and/or mixtures thereof, c2) 2 wt % to 45 wt % of a polymer selected from polyisobutylene, polyisobutylene/butene copolymer, polymethacrylates, polyesters and mixtures thereof, c3) 0.5 wt % to 20 wt % of a solid lubricant.

An environmentally acceptable lubricating grease, comprising: a) 50 wt % to 90 wt % of a biodegradable base oil comprising a biodegradable ester as base oil; b) 3 wt % to 25 wt % of a thickener selected from b1) 3 wt % to 12 wt % biodegradable calcium soap, b2) 3 wt % to 25 wt % bentonites, b3) and mixtures thereof; c) 4 wt % to 40 wt % additives, comprising c1) 1 wt % to 12 wt % fumed silicon dioxide and/or polytetrafluoroethylene and/or mixtures thereof, c2) 2 wt % to 45 wt % of a polymer selected from polyisobutylene, polyisobutylene/butene copolymer, polymethacrylates, polyesters and mixtures thereof, c3) 0.5 wt % to 20 wt % of a solid lubricant.

A silicone grease composition having high friction characteristics and wear characteristics is disclosed. The silicone grease composition is provided by adding a zinc salt (B) containing, at a mass ratio from 1:99 to 99:1, a zinc dialkyldithiophosphate (B1) and a zinc dialkyldithiocarbamate (B2) as an extreme-pressure additive to a silicone oil (A). A method for transmitting torque of a clutch or a torque limiter mechanism is also disclosed.

A silicone grease composition having high friction characteristics and wear characteristics is disclosed. The silicone grease composition is provided by adding a zinc salt (B) containing, at a mass ratio from 1:99 to 99:1, a zinc dialkyldithiophosphate (B1) and a zinc dialkyldithiocarbamate (B2) as an extreme-pressure additive to a silicone oil (A). A method for transmitting torque of a clutch or a torque limiter mechanism is also disclosed.

A lubricating grease composition containing a base oil having a kinematic viscosity of 10 mm.sup.2/s or more and 60 mm.sup.2/s or less at 40° C.; a thickener containing at least one soap selected from a metal soap and a metal complex soap; and a solid lubricant containing porous polyamide particles. An amount of the porous polyamide particles blended is 1% by mass or more and 20% by mass or less based on a total mass of the lubricating grease composition.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.