Patent ID: 9140266
Filing Date: 2015-09-22
Classification: F04D

Abstract:
1. A cooling fan comprising: a base; a lid arranged above the base; a fan wheel having a shaft rotatably coupling with the base and a highest point spaced from the lid by a first gap; and an auxiliary shaft assembly arranged between a top of a hub of the fan wheel and a bottom face of the lid, with a second gap formed between the auxiliary shaft assembly and the top of the hub or between the auxiliary shaft assembly and the bottom face of the lid, wherein the second gap is smaller than the first gap, wherein the base has an air channel formed between the lid and the top of the hub, wherein the air channel includes at least one first opening and at least one second opening, and wherein the fan wheel further includes a plurality of blades received in the air channel, wherein the shaft extends from the hub, wherein the hub has a radial extent; wherein the plurality of blades extend radially with respect to the shaft to the radial extent of the hub and axially extend parallel to the shaft from the top of the hub to the highest point, with the plurality of blades located intermediate the hub and the bottom face of the lid, and with the plurality of blades located concentrically around the auxiliary shaft assembly and in the air channel within the radial extent of the hub between the top of the hub and the bottom face of the lid.