FLUID DYNAMIC PRESSURE BEARING, SPINDLE MOTOR HAVING THIS FLUID DYNAMIC PRESSURE BEARING AND RECORDING DISK DRIVING DEVICE HAVING THIS SPINDLE MOTOR

摘要

PROBLEM TO BE SOLVED: To miniaturize and thin the whole motor, by securing bearing rigidity of respective bearing parts, accuracy such as squareness of a shaft and a rotor hub and a shaft directional dimension of a tapered seal part.;SOLUTION: In this fluid dynamic pressure bearing of one example, a radial bearing part provided with a dynamic pressure generating groove for inducing dynamic pressure in a lubricating fluid when rotating a rotor, is formed between an outer peripheral surface of the shaft and an inner peripheral surface of a sleeve. An upper thrust bearing part provided with the dynamic pressure generating groove for inducing the dynamic pressure in the lubricating fluid when rotating the rotor, is formed between an under surface of a rotor upper wall part and an upper end surface of a bearing housing. A lower thrust bearing part provided with the dynamic pressure generating groove for inducing the dynamic pressure in the lubricating fluid when rotating the rotor, is formed between a lower end surface of the sleeve and an upper surface of a thrust plate.;COPYRIGHT: (C)2006,JPO&NCIPI