| 摘要 |
PURPOSE:To attain a disc device with small size, low cost and low noise, by providing a magnetic fluid seal arranged near a bearing seat, a vent hole provided near the magnetic fluid seal and an air filter provided on the vent hole. CONSTITUTION:The magnetic fluid seals 16 and 18 are provided at the inside of bearings 8 and 10, an external air invaded in the housing through the bearing is interrupted completely to keep the air in the housing clean. The vent hole 20 to supply the air leaked from minute gaps of the housing is provided near the seal 10 and the air filter 22 is provided on the vent hole 20 to remove dusts. When a rotary shaft 6 is rotated via a pully 40, a spindle hub 12 and a magnetic disc 14 are rotated integrally with the rotary shaft 6 and air in the housing flows from the center of the disc 14 to the outer circumference. A barrier 24 and an upper side housing 4 form an air circulating path and an air flow flowing from the outer circumference to outside of the disc 14 is circulated to the center of the spindle hub 12 through the air circulating path. |
