Bearing system

A bearing system comprising:

• a bearing defining an inner surface;
• a shaft defining an outer surface rotatably received in the inner surface of the bearing, wherein one of the inner surface and the outer surface being coated with a nano-structured coating having good hydrophilic property, the other of the inner surface and the outer surface being coated with a hydrophilic film;
• and
• lubricant being filled between the outer surface and the inner surface, the lubricant comprising a polymer material with a hydrophilic functional group having hydrophilic property and a hydrophobic functional group having hydrophobic property;
• wherein the nano-structured coating is made of one of TiN, DLC, TiAlN, TiCN, CrN and WC.

A bearing system comprising:

• a bearing;
• a shaft rotatably received in the bearing, the bearing and shaft being coated with hydrophilic coatings, respectively;
• and
• lubricant filled between the coatings, the lubricant being made of polymer material comprising a hydrophilic group and a hydrophobic group;
• wherein one of the coatings has a nano-structure;
• and
• wherein the lubricant is made of perfluorinated polyether.