| 摘要 |
PURPOSE:To improve an input/output characteristic of a video/sound signal and to prevent a failure due to locking of a rotating member when a burr or dust in air is mixed thereto by forming an opposite face to a spiral groove setting face with a flat plate and a supporting member supporting elastically the flat plate to float stably a tape on a rotary head assembly. CONSTITUTION:The delivery pressure of a pump-out type spiral groove is changed inversely proportional to the square of clearance (g), and when the (g) is zero, an infinite pressure is generated theoretically. The initial setting is attained by providing a proper preliminary pressure between the spiral groove 9 and the flat plate 10 on the opposite face so as to reduce the clearance (g) to zero. A dynamic pressure is produced by giving a rotating speed (omega) to the rotating member 15 and the clearance (g) is produced between the spiral groove 9 and the flat plate 10 of the opposite phase. Even if a burr produced at the processing of spiral groove is fallen down or dust in air is mixed into the clearance (g) of as minute as several tens of mu, it is avoided by the flat plate held elastically which deforms partially. Thus, there exists no possibility to make the rotation disable due to locked rotating member. |
