A drive device includes a slide bearing; a shaft that passes through the slide bearing; a gear that is fixed to the shaft; and a grease composition that is held in a clearance between the slide bearing and the shaft. At least one of the slide bearing and the shaft is made of a resin. The clearance is in a range of 10 to 110 μm. 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.

A drive device includes a slide bearing; a shaft that passes through the slide bearing; a gear that is fixed to the shaft; and a grease composition that is held in a clearance between the slide bearing and the shaft. At least one of the slide bearing and the shaft is made of a resin. The clearance is in a range of 10 to 110 μm. 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.

A drive device includes a plurality of gears; and a grease composition that is held on a tooth flank of at least one gear of the gears. The at least one gear is made of a resin. The grease composition contains a hydrocarbon base oil, lithium soap serving as a thickener, and olefin resin powder. A weight ratio between the hydrocarbon base oil and the lithium soap in the grease composition 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.

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.