PURPOSE: To shorten axial length of a spindle motor, to prevent rolling noise and to lengthen service life of bearing by forming the load fixing hub of a rotary shaft of a structural material having low specific gravity and additionally fixing a rotor magnet and a yoke.
CONSTITUTION: A pair of ball bearings 4a, 4b are fixed to the inside of a shaft boss formed integrally with a bracket 1 so that they can bear a rotary shaft 2 rotatably, and a stator 3 is secured to the outer circumference of the bearing boss 7. The rotor is a combination of a hub 6 composed of a structural material having low specific gravity such as aluminum alloy and a yoke 8 composed of magnetic material. Fitting part 6a of the hub 6 comprises a cylindrical outer circumferential face perpendicular to the axis, and the hub 6 is secured through the yoke 8. By such arrangement, rolling noise is reduced and highly accurate rotation is maintained.
| JPH1080080 | BRUSHLESS MOTOR |
| WO/2016/156511 | DC-MOTOR |
FUJII TATSUFUMI
NOZU SEIICHI
Next Patent: OUTER ROTOR TYPE DYNAMO-ELECTRIC MACHINE PROVIDED WITH PERMANENT MAGNET