INNER ROTOR TYPE SPINDLE MOTOR

• Main Author: KODAMA MITSUO
• Format: Patent
• Language: English
• Published: 21.12.2001
• Edition: 7
• Subjects: BEARINGS; BLASTING; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; ELEMENTS OR CRANKSHAFT MECHANISMS; ENGINEERING ELEMENTS AND UNITS; FLEXIBLE SHAFTS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERATION; HEATING; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; LIGHTING; MECHANICAL ENGINEERING; PHYSICS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; SHAFTS; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To simplify assembly and miniaturize an inner rotor type spindle motor using an air fluid bearing. SOLUTION: In an inner rotor type spindle motor 100, a dynamic pressure groove is formed by an inner sleeve 17 that is provided at the outer-periphery of a shaft 2 being erected at a motor base 1, an outer sleeve 16 that is provided at the outer-periphery part of the inner sleeve 17 with a specific internal, a hub 5 that is mounted to the outer-periphery part of the outer sleeve 16, a rotor yoke 13 that is mounted to the outer-periphery part of the outer sleeve 16, and the outer-periphery surface of the inner sleeve 17 and the inner-periphery surface of the outer sleeve 16 to compose a radial dynamic pressure bearing. Also, the dynamic pressure groove is formed between upper and lower thrust plates 15 and 14 opposing the upper and lower surfaces of the outer sleeve 16 to compose a thrust dynamic pressure bearing. In the spindle motor 100, the diameter of the inner-periphery of the hub 5 and that of the inner-periphery of the rotor yoke 13 are set to nearly the same diameter.