MOTOR AND HARD DISK DRIVE INCLUDING THE SAME

摘要

A motor according to an embodiment of the present invention includes: a sleeve which supports a shaft using a lubricating fluid as a medium; and a rotor which is fixed on and rotates in conjunction with the shaft, and has a surface facing the sleeve. A thrust dynamic pressure groove is equipped on either side of the rotor the surface facing the sleeve. An extended groove is equipped on the other side of the rotor the surface facing the sleeve, and the parts of the extended groove is extended to the outside of the thrust dynamic pressure groove to face the thrust dynamic pressure groove.