Patent ID: 7866890

Claim:
A spindle motor having a fluid dynamic bearing system comprising: a base, a stationary shaft connected to the base, a hub rotatably supported with respect to the shaft, a first bearing plate and a second bearing plate that are disposed at a mutual spacing about the shaft and connected to the hub, a bushing that is disposed between the first bearing plate and the second bearing plate and separated from the first bearing plate by a first gap at least partly filled with bearing fluid and separated from the second bearing plate by a second gap at least partly filled with bearing fluid, a first stopper plate and a second stopper plate that are fixedly connected to the shaft, the first stopper plate abutting one side of the first bearing plate and separated from the first bearing plate by a first bearing gap filled with bearing fluid, the second stopper plate abutting one side of the second bearing plate and separated from the second bearing plate by a second bearing gap filled with bearing fluid, a first fluid dynamic bearing system which is disposed about the first bearing plate, a second fluid dynamic bearing system which is independent of the first fluid dynamic bearing system and which is disposed about the second bearing plate, and an electromagnetic drive system.