摘要 |
A spindle motor for use in a disk drive having a rotor assembly and a stator assembly. The rotor assembly has a hub and a rotating shaft with an outer diameter, the hub being mounted for rotation on the rotating shaft. The stator assembly has a bearing sleeve with a bottom opening, the rotating shaft being inserted into the bearing sleeve for rotation. A counter-plate is inserted into the bottom opening of the bearing sleeve thereby closing the bottom opening. A thrust plate is mounted on the rotating shaft in opposing relationship with the counter-plate, the thrust plate having an outer diameter. A fluid dynamic thrust bearing is formed between the counter-plate and the thrust plate. A ratio between the outer diameter of the shaft to the outer diameter of the thrust plate is reduced to reduce spindle motor's power consumption. |