| 摘要 |
PURPOSE:To reduce a load at the time of moving a carriage, enable a high-speed scanning movement and contrive a longer useful life, by using a dynamic- pressure bearing at a bearing part for a head carriage. CONSTITUTION:A dynamic-pressure bearing 25 for a carriage guide shaft 3 is fitted into a through-hole 2a of a head carriage 2. The bearing 25 is molded from an abrasion-resistant synthetic resin, is press fitted into the hole 2a, and has an inner peripheral surface provided with a plurality of oblique grooves, with the direction of inclination of each groove being opposite to that of the adjacent groove. When the carriage 2 is moved in the direction of an arrow A, a positive pressure is generated relative to the surface of a guide shaft 3 through compression of a fluid by the combinations of the grooves 251-252 and 253-254, and when the carriage 2 is moved in the direction of arrow B, a positive pressure is also generated by the combinations of the grooves 252-253 and 254-255. Accordingly, the carriage 2 is reciprocated extremely smoothly under a low load and a small load variations. |
