An engine cooling fan and electric motor assembly is used to provide radiator and A/C condenser cooling airflow in engine compartments of many vehicles. The engine compartment itself is a high-temperature environment. To complicate matters, the motor generates its own internal heat during the normal course of operation. The internally generated heat is primarily due to Joule heating caused by electric current passing through its rotor and stator coils, and brush losses. High temperatures can greatly increase the wear of motor brushes and bearings, and significantly reduce motor life.
One solution to these problems is to provide cooling holes 44a, 44b in FIG. 4, to admit cooling air through the motor 22. The invention provides additional strategies to cool motor 22.