| 摘要 |
The present invention is directed to an apparatus 245 and method of etching grooves 235 in a shaft 175. In one embodiment, a cathode 250 is provided for electrochemically etching grooves 235 in an outer surface 215 of the shaft 175 to form a fluid dynamic journal bearing 225. The cathode 250 includes an electrically conductive cylindrical substrate 270 having an inner surface 275 that corresponds to the outer surface 215 of the shaft 175, the inner surface 275 having raised lands 280 corresponding to areas in which the grooves 235 are to be formed. A layer of electrically insulating material 285 covers the inner surface 275 of the substrate 270 between the lands 280 to preclude etching of the shaft 175 in areas between the lands. Preferably, the lands 280 are arranged so that the grooves 235 etched in the shaft 175 form one or more fluid dynamic bearings. In another aspect, the invention provides a process for electrochemically etching grooves 235 in the outer surface 215 of the shaft 175 to form a fluid dynamic bearing.
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