Patent ID: 7699587

Claim:
A centrifugal blower comprising: a centrifugal fan including a hub adapted for rotation about a central axis, and a plurality of blades coupled for rotation with the hub; a motor having a drive end and an opposite end, the motor including a drive shaft drivingly connected to the hub of the centrifugal fan, the drive shaft extending from the drive end of the motor, and the motor having therethrough a motor airflow path for cooling the motor, the motor airflow path having an inlet near the opposite end of the motor; and a housing structure including a blower housing portion at least partially defining a space in which the fan is substantially enclosed, the space having a blower inlet and a blower outlet; a motor housing portion supporting the motor; a flange portion at least partially supporting the motor housing portion on the blower housing portion; and a cooling air path having a cooling air path inlet directly communicating with the space and a cooling air path outlet communicating with the inlet of the motor airflow path, the cooling air path having an upstream portion that extends axially in the direction from the opposite end of the motor toward the drive end of the motor, and the cooling air path having a downstream portion that extends axially in the direction from the drive end of the motor toward the opposite end of the motor, wherein no portion of the cooling air path between the cooling air path inlet and the cooling air path outlet is defined by the blower housing portion, and wherein the upstream portion of the cooling air path is positioned between the fan and a surface of the blower housing portion opposite the blower inlet and at least partially defining the space.