A drive device includes a gear having a hole; a shaft that passes through the hole; and a grease composition that is held in a clearance between the shaft and an inner peripheral surface of the hole. The gear rotates on a peripheral surface of the shaft. At least one of the gear and the shaft is made of a resin. The clearance is in a range of 10 to 110 m. The grease composition contains a hydrocarbon base oil and lithium soap serving as a thickener. A weight ratio of the hydrocarbon base oil to the lithium soap is in a range of 94.5:5.5 to 96.0:4.0. A consistency of the grease composition is in a range of 360 to 400.

The present invention relates to the field of lubricant, and specifically provides a lubricant composition and its preparation method and use. The lubricant composition comprises a base oil and rubber particles having radiation crosslinked structure dispersed therein, wherein the base oil is continuous phase and the rubber particles are dispersed phase. The viscosity of the lubricant composition of the present invention can be effectively adjusted as temperature changes. As compared with the lubricant composition comprising chemically crosslinked rubber particles, it has a lower viscosity at low temperatures and a higher viscosity at high temperatures, and has a relatively high viscosity index, which can meet the application requirements at the temperature above 200? C. In addition, the lubricant composition of the present invention also has excellent antiwear and friction-reducing properties.