High resistivity bearing balls for spindle motor isolation

摘要

A disc drive for storing and retrieving data from at least one memory storage disc includes a drive base and a spindle motor. The spindle motor includes a rotor hub, a shaft, a bearing sleeve, and a bearing unit. The bearing unit is operably coupled to the rotor hub and includes an inner race secured to the shaft, an outer race secured to the bearing sleeve, and bearing balls fitted between the inner race and the outer race. The bearing balls rotatably support the rotor hub about an axis. At least one structural element of the spindle motor has a high resistivity so as to electrically isolate the hub from the base. In another embodiment, the drive base has an interface surface for coupling with the spindle motor. The interface surface includes a layer of high resistivity material. In another embodiment, the bearing ball is made of ceramic or ruby material to improve performance characteristics. In yet another embodiment, an insert is inserted between the bearing sleeve and the shaft to improve performance characteristics.