| 摘要 |
PURPOSE:To prevent a lubricant scattering outside, by constituting the lubricant being sealed in space between a carriage and a rotary shaft with a conductive fluid in material, while setting up a shifting field generator at the inner circumferential side of the carriage, and shifting the conductive fluid to the side of a carriage intermediate part. CONSTITUTION:A spiral groove is formed on an outer circumferential surface of a rotary shaft 3, while a dynamic pressure bearing is formed by a lubricant consisting of a conductive fluid to be sealed in a space 4 between a carriage and the rotary shaft 3 with rotation in the rotary shaft 3. Therefore, the rotary shaft 3 is supported thereat without contacting the carriage 1. The lubricant tries to scatter outside from both ends of the space 4 but a shifting magnetic field to be formed by a coil C shifts to an arrow direction so that the conductive fluid comprising the lubricant is attractedly shifted, to the arrow direction by dint of magnetic force of this shifting field, thus scattering of the lubricant to the outside is prevented. |
