DYNAMIC VIBRATION ABSORBING DEVICE FOR ROTARY BODY AND HARD DISK DRIVE ADOPTING THE SAME

摘要

PROBLEM TO BE SOLVED: To efficiently absorb the rotational vibration of a rotary body without being restricted by the rotational speed of the rotary body by allowing the device to include the rotary body and at least one massive body to be arranged at the surroundings of the rotary body and connecting the rotary body and the massive bodies so that the massive bodies can move elastically in the radial direction of the rotary body. SOLUTION: Massive bodies 30 are arranged symmetrically with respect to the rotary shaft of a rotary body 20 and they are positioned in respective withdrawn parts so as to maintain the same intervals in the circumferential direction of the rotary body 20. Each massive body 30 is provided with one pair of pieces made of metal so as to be symmetrically coupled with an elastic ring 40. Each connecting means is interposed between a main body 21 and a cover 23 elastically in the withdrawn part and is provided with the elastic ring 40 supporting the massive body 30. When the rotary body 20 is revolved together with magnets 13 to be actuated by mutual electromagnetic forces with coils 11, the massive bodies 30 move independently respectively to fixed palces in the radial direction of the rotary body 20 by elastic displacements of the elastic rings 40 to compensate eccentric mass.