Patent ID: 6764590
Filing Date: 2004-07-20
Classification: B23H,F16C

Abstract:
Apparatus for electrochemically etching grooves in a surface of a conical bearing to be utilized in a fluid dynamic bearing, comprising a frame for holding the cone about an axis and facing a movable electrode movable along the axis, the electrode being axially movable and having a surface carrying a groove pattern to fix on an inner surface of the cone,a source of electrolyte to be pumped at a fixed static pressure rate between the surface of the movable electrode and the inner surface of the cone, and a static fixture for supporting the electrode for movement toward and away from the inner surface of the cone with minimal frictional restriction, and a force biasing the electrode surface toward the inner surface of the cone so that the gap through which the electrolyte flows between the inner surface of the cone and the surface of the electrolyte is determined primarily by the static flow rate of the electrolyte and the force bias of the electrode toward the inner surface of the cone.