Quiet and efficient motor cooling fan assembly for a blender

摘要

A blender (10) includes a pitcher assembly (11), a motor and housing assembly (12) and a cooling fan and noise muffling assembly (13). The pitcher assembly (11) includes a blender pitcher (14) having a mixing blade (15) therein driven by a motor (24) positioned in the housing assembly (12) which includes a base frame (31) and a cover (21). The motor (24) is positioned in a pedestal (37) formed in the base frame (31). The base frame (31) is provided with air intake apertures (53, 55). The fan and noise muffling assembly (13) includes a radial fan (60) driven by the motor (24) and a muffler housing (62) which includes a generally cylindrical side wall (68). Air is drawn in through the apertures (53, 55) by the fan (60) and is caused to pass by the motor (24) within the pedestal (37) to cool the motor (24). It then passes through an aperture (66) in an orifice plate (61) and is directed by the fan (60) against the side wall (68). At that point the air turns ninety degrees downwardly and is directed into four chambers (73) below the fan (60), the chambers (73) being formed by ribs (74) extending radially outward from a hub member (75) positioned below the fan (60). The air then again turns ninety degrees inwardly into two chambers (76) divided by a rib (77) below the hub member (75) whereby it turns again and leaves the blender (10) through an air exit aperture (70).