| 摘要 |
PURPOSE: To form a resin layer on a dynamical pressure surface simply, at a low cost, thickly and with high accuracy by forming a shaft body which consists of aluminum or aluminum alloy, and also attaching lubricative resin on the outer circumference of a shaft body. CONSTITUTION: A dynamic pressure generating groove 33 is formed in a closing condition in which the groove 33 is not communicated with the axial direction both end parts of the dynamical pressure surface of a shaft inserting body 32 side on which the groove 33 is formed. In such dynamical pressure bearing device, tightly sticking property of lubricative resin 34 is improved while utilizing rough surface of a bearing body 31 made of aluminum or aluminum alloy, the lubricative resin 34 is formed without pre-working, and also cut working is enabled. When cut working is carried on an outer circumference, a dynamical pressure generating groove is formed simultaneously, and size accuracy is improved by cut working to more extent. Since dynamical frictional coefficient of the lubricative resin 34 is set to 0.6 and less and a bending elastic coefficient is set to 5 GPa or more, generation of seize and the like is eliminated at the time of rotation. |
