| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of wear and breakage by a method wherein a protection film is formed on either at least the raceway surface of the bearing ring of a rolling bearing suitable for high speed rotation application or the surface of a rolling body and a lubrication film formed of a fluoropolymer having a functional group is formed on the surface of the protection film. SOLUTION: A dental hand piece is provided on both sides of a turbine blade fixed on the intermediate part of a rotary shaft with a rolling bearing 4 to rotatably support the rotary shaft at a housing. The rolling bearing 4 has a lubrication layer 9 formed on the raceway surfaces 5a and 6a of inner and outer rings 5 and 6 being a bearing ring. The lubrication layer 9 has a protection film formed or the surfaces of the raceway surfaces 5a and 6a and lubrication films formed on the surfaces. The thickness of the lubrication film is 0.2 μm or less and preferably set to a value approximately equal thereto. In this case, the lubrication film is formed of lubrication oil prepared such that a mixture with perfluoropolyether or its derivative is diluted to 0.25 mass % by a dilution solvent. |
