Patent ID: 7819641

Claim:
An air mover which comprises: a tubular fan housing; a motor which includes a motor housing; a shaft which is driven by the motor; an impeller which includes an impeller hub that is connected to the shaft proximate an upstream end of the motor housing; an outlet guide vane assembly which is positioned downstream of the impeller and which includes a guide vane hub that is connected to or formed integrally with the motor housing and a plurality of guide vanes that extend between the guide vane hub and the fan housing; a diffuser section which is positioned downstream of the outlet guide vane assembly and which includes a diffuser tube that is connected to or formed integrally with the fan housing and a tail cone that is connected to or formed integrally with a downstream end of the motor housing, the tail cone comprising a downstream end and an aperture which extends axially through the downstream end to a location downstream of the tail cone; wherein during operation of the air mover, the motor spins the impeller to generate a flow of air through a flowpath which comprises an outer boundary defined by the fan housing and the diffuser tube and an inner boundary defined by the impeller hub, the guide vane hub and the tail cone; the motor comprising at least one inlet opening proximate the downstream end of the motor housing which is in fluid communication with the aperture and at least one outlet opening proximate the upstream end of the motor housing which is in fluid communication with a portion of the flowpath located upstream of the outlet guide vane assembly; wherein during operation of the air mover, a pressure difference between the aperture and the outlet opening causes a portion of the flow of air to flow into the aperture, through the inlet opening and out the outlet opening to thereby cool the motor; wherein the motor further comprises a front end cap which is connected to an upstream end of the motor housing, a rear end cap which is connected to a downstream end of the motor housing, and a rotor which is connected to or formed integrally with the shaft and is rotationally supported by a front bearing mounted in the front end cap and a rear bearing mounted in the rear end cap; wherein the at least one inlet opening is formed in the rear end cap and the at least one outlet opening is formed in the front end cap; and wherein the motor housing comprises an axially extending front extension which is positioned in an axial recess in the impeller hub, and wherein the outlet opening communicates with the flowpath through an annular space between the front extension and the recess.