metal trained go amp; auml; use r amp; t.; r w amp; auml; rmeabf amp; t.; hrende l amp; t.; fter

摘要

A casing for a heat-dissipating fan includes a bottom board 10a, a plurality of sidewalls 101 extending from the bottom board 10a and magnetic pole faces 13 integrally formed by punching a magnetically conductive plate 1. Stator coil assembly 20 is mounted on base 12. An axial hole 141 is defined in the base 12 of the bottom board 10a, and a bearing 142 is mounted in the axial hole 141 for rotatably holding a shaft 31 of a rotor 30. The magnetic pole faces 13 surround the axial hole 141 and are adjacent to the coil assembly 20 of the stator. Groove 121 receives the lead 41 of the Hall sensor 42 which mounts in aperture 131. Axial and radial fan embodiments are disclosed and the poles may been notched 132 to assist starting. The rotor is axially retained by a circlip adjacent a thrust plate.