You maintain ceiling fans by cleaning them. They have sealed bearings so they don't usually need any type of lubrication. You'll want to dust the blades regularly, using a vacuum cleaner to get into inaccessible areas. You may want to remove the light cover and clean it out and any exposed areas for dust. You may need to use a wet cleaning solution of some kind, particularly on fans near kitchen areas, where grease buildup mixes with dust to create grime that can destroy your fan.