| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor for recording disk driving and a recording disk drive by the motor capable of preventing negative pressure and the excessive floating of lubricating oil and being easily assembled, and having high reliability and durability. <P>SOLUTION: Upper and lower radial dynamic pressure bearings in which herring bone grooves are provided, are formed between the inner peripheral surface of a sleeve and the outer peripheral surface of an outer cylinder member. A thrust dynamic pressure generating groove in which a spiral groove for inducing pressure applied radially inward is provided during rotation, is formed between the underside of the upper wall of a rotor hub and the top end surface of the sleeve. A hydrostatic bearing is formed between the lower end surface of a shaft and the upper end surface of a seal member. A helical communicating hole for communicating a clearance formed between a thrust dynamic pressure bearing and the hydrostatic bearing, and an adhesive groove parallel with the communicating hole, are formed between the outer peripheral surface of the shaft and the outer peripheral surface of the outer cylinder member. <P>COPYRIGHT: (C)2004,JPO |
