THRUST DYNAMIC PRESSURE BEARING, AND SPINDLE MOTOR AND INFORMATION RECORDING AND REPRODUCING DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To stabilize the bearing performance to improve reliability and durability by preventing leakage of lubricating oil due to bubbles of a thrust dynamic pressure bearing of a herringbone groove. SOLUTION: An auxiliary groove 140 deeper than the pump-in type herringbone groove 13 for generating dynamic pressure is provided to connect from the inner peripheral part of the bearing to the outer peripheral part of the bearing with a gently descending pressure gradient, whereby the bubbles existing in the inner peripheral part of the bearing are guided to the outer peripheral part of the bearing through the auxiliary groove 14 to be discharged from the gas/liquid boundary surface to the outside of the bearing so that leakage of lubricating oil due to the bubbles can be prevented. COPYRIGHT: (C)2005,JPO&NCIPI