Fan structure

Abstract

A fan includes a blade assembly rotatably supported in a frame. The blade assembly includes a cylinder having an outer surface to which blades are mounted and an inner surface to which magnets are mounted. The blade assembly has an axle concentric with the cylinder. The frame includes a casing made of silicone steel that is fixed inside the frame and supports a bearing device. The bearing device defines a central bore rotatably receiving the axle of the blade assembly therein with the cylinder of the blade assembly fit over and spaced from the casing. Windings of conductive wires are encased and fixed in the casing and surround the bearing device for being electrically powered to generate a magnetic field that interacts with the magnetic means of the blade assembly to rotate the blade assembly. The casing includes opposite upper and lower disks with tabs extending between the upper and lower disks. The tabs extends from a circumference of the upper disk and have free ends fit into corresponding notches defined in the lower disk with a major surface of the tabs extending along a circumferential direction of the disks. Portions of the lower disk project beyond the tabs and are positioned in correspondence to the magnets of the blade assembly for magnetically attracting and thus maintaining the blade assembly in a close position with respect to the lower disk to eliminate “pump” action of the blade assembly.

Dependencies are inferred from the claim text.