Drive device, image forming apparatus, and grease composition
View Patent ↗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.
1. A drive device comprising:
a plurality of gears; and
a grease composition on a tooth flank of at least one of the plurality of gears, wherein
the at least one of the plurality of gears includes a resin,
the grease composition contains a hydrocarbon base oil, lithium soap serving as a thickener, and a solid lubricant including 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, and
a consistency of the grease composition is in a range of 360 to 400.
2. The drive device according to claim 1 , wherein a kinetic viscosity of the hydrocarbon base oil is equal to or smaller than 20 mm 2 /s at 40° C.
3. The drive device according to claim 1 , wherein the grease composition includes a styrene thickener.
4. The drive device according to claim 1 , wherein the at least one of the plurality of gears includes a polyacetal resin.
5. The drive device according to claim 1 , wherein a module of each of the gears is in a range of 0.3 to 1.
6. The drive device according to claim 1 , wherein an absolute value of a sliding ratio between gears that are engaged with each other is equal to or larger than 1.
7. The drive device according to claim 1 , wherein a reduction ratio between gears that are engaged with each other is equal to or larger than 4, and an absolute value of a sliding ratio between the gears is equal to or larger than 4.
8. An image forming apparatus comprising the drive device according to claim 1 .
9. A grease composition included in the drive device according to claim 1 .
10. The drive device according to claim 1 , wherein the grease composition includes olefin resin powder that is a polyethylene powder.
11. The drive device according to claim 1 , wherein the grease composition includes olefin resin powder that is substantially insoluble in the base oil.
12. The drive device according to claim 1 , wherein the grease composition includes olefin resin powder that is dispersed in the base oil as solid particles.