Spindle motor with multiple thrust plate fluid dynamic bearing

摘要

A hydrodynamic bearing which is relatively insensitive to changes in load and rotational speed, wherein the hydrodynamic bearing is useful in a spindle motor (14) for a disc drive (10) or the like which is stiffer than known standard spindle motors so that the stability of the system and specifically of the actuator arm and transducer (20) relative to the rotating disc (16) is optimized. The hydrodynamic bearing can also be used as a bearing cartridge or as the cartridge that may be incorporated into a spindle motor or the like, where the bearing includes a shaft (75) and at least two independent bearings each comprising a thrust plate (90 and 92) supported on the shaft and a counter plate incorporated in a sleeve (72) which is capable of relative rotation around the shaft.