| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic pressure bearing device which is excellent in workability, which is capable of further reduction of diameter, which is difficult to be damaged, and which is excellent in wear resistance, and in impact resistance. SOLUTION: This device is a dynamic pressure bearing device which is provided with relatively rotating shaft 1 and sleeve 3, and which has a dynamic pressure generating groove at least in either of the outer peripheral surface of a shaft 1 and the inner peripheral surface of the sleeve 3. The sleeve 3 is made of copper alloy, and the shaft 1 is a material having the coefficient of thermal expansion which is equal to or grater than the coefficient of thermal expansion of copper alloy, and the shaft is made of material having Vickers hardness of 300 or less before heat treatment and Vickers hardness of 300 or more after heat treatment. As material for the shaft, a heat resisting steel obtained by adding manganese or nickel to austenitic stainless steel, or beryllium copper can be used.
|
