High pressure boundary seal

摘要

A high pressure boundary seal adjacent at least one of the bearings of the spindle motor. The motor itself includes a shaft, typically a fixed shaft and a rotor supported by bearings and rotating outside the shaft. The high-pressure boundary seal comprises a ring which surrounds the shaft across a small gap and is supported from and rotates with the rotor or hub. In a first embodiment, a herringbone pattern is defined on the inner surface of the ring or the outer surface of the shaft. The upper and lower sections of the herringbone pattern are substantially equal so that a zone of high pressure is established at about the center of the pattern. This high pressure boundary zone prevents the flow of any contaminants from the interior of the motor or the bearing between the shaft and the sealing ring out into the interior section of the disc drive housing where they could potentially contaminate the disc.