| 摘要 |
PURPOSE:To stabilize positioning operation by aligning the position of a rotary center shaft to a center position of an impact to the center of gravity of a magnetic head and the whole oscillation part. CONSTITUTION:The rotary center shaft 3 is so arranged that xS=xG+I/MXG, where M is the total mass of the oscillation part consisting of the magnetic head 1, a head arm, the rotary center shaft 3, and the movable part 5 of a driving motor, I is moment of inertia, and (xG, 0) and (xS, 0) are coordinates of the center 8 of gravity and the rotary center shaft 3. Consequently, the rotary center shaft 3 is aligned to the center of the impact and a core gap 7 is held in a stationary state. Namely, when force F(t) operates on the rotary center shaft 3 in the direction of a (y) axis 10, the kinetic equation of the center 8 of gravity in the direction of the (y) axis 10 is as shown by I, where yG is fine displacement. When time t is 0 and initial displacement and an initial speed are also 0, an equation II holds. The kinetic equation in the rotational direction around the center of gravity, on the other hand, is as shown by III. When time t is 0 and an initial rotation angle and an initial angular speed are 0, an equation IV holds. Therefore, when the fine displacement of the core gap part 7 in the direction of the (y) axis 10 is denoted as yH, theta is considered to be fine, so an equation V holds. However, yH=0 because xS=I/MXG+XG. |
