US Patent 7699587 Cooling channel for automotive HVAC blower assembly

A centrifugal blower comprising a cooling air path having an inlet communicating with a blower space and an 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.