| 摘要 |
<p>An apparatus and method for moving a flow of air and particulates through a vacuum cleaner. In one embodiment, the apparatus includes a rotary propulsion device (200) having a rotatable hub (211) with a plurality of vanes (213). The flow area between the vanes (213) can be approximately constant from a region adjacent the hub (211) to a region spaced apart from the hub (211). A housing (230, 260) is disposed about the vanes (213) and the flow of air and particulates can enter the housing (230) through a single inlet aperture (231) and exit the housing (230, 260) through two spaced apart outlet apertures (232). The vanes (213) can be arranged on the hub (211) such that when one vane (213) is centered relative to one of the outlet apertures (232a, 232b), the vane closest to the other outlet aperture is offset from the center of that aperture to control the noise generated by the propulsion device (200).</p> |
