| 摘要 |
PURPOSE:To keep the dynamic balance of a rotary body including a rotor for a rotary magnetic head in a final package state automatically with high precision, by providing a dynamic balancing mechanism at one end of the rotor in its rotary shaft direction. CONSTITUTION:At one end in the rotary shaft direction, a rotor 11 for a rotary magnetic head is equipped with a dynamic balancing mechanism consisting of an external ring 7 for an annular steel-ball guide track, an internal ring 8 for the annular steel-ball guide track, and several steel balls 9 held in a groove formed between the external fing 7 and internal ring 8. When the rotary body of the assembly in a final package state and the steel balls 9 resonate at some resonance frequency during the stationary rotation of the rotary body, the steel balls 9 move automatically where the mass unbalance of the rotary body is canceled, thus holding the dynamic balance of the rotary body. This constitution eliminates the need for the mechanical addition and reduction of the mass, and keeps the high-precision balance automatically in the final package state. |
