Patent ID: 7119464

Claim:
A spindle motor, particularly for the purpose of driving platters in hard disk drives, comprising: a base plate; a stator arrangement that is stationary with respect to the base plate; a shaft and a hydrodynamic bearing system on which a rotary driven rotor connected to the shaft is rotatably supported, the hydrodynamic bearing system including a liquid lubricant; the shaft being formed at least partly as a hollow shaft and the rotor having a shaft shoulder aligned concentrically to its rotational axis, said shoulder disposed within and firmly fixed to the shaft; said bearing system comprising at least one radial bearing region formed by an outer surface of said shaft and a bearing sleeve having an inner surface surrounding said shaft, said bearing system further comprising a thrust bearing formed by a thrust plate arranged at a lower end of the hollow shaft and a covering plate; said thrust plate and said hollow shaft constituting a monolithic element.