Double counter-rotating type air blower for radiator for vehicle, has specific work ratio of downstream axial flow fan with respect to upstream axial flow fan

摘要

The double counter-rotating type air blower (3) has an upstream axial flow fan (31) and a downstream axial flow fan (32). A fan shroud (4) has an airflow-guidance portion (42a) that changes the channel area of the air path to air flow upstream toward air flow downstream from a region in which the blower is held. The work ratio of the downstream axial flow fan with respect to the upstream axial flow fan, is lesser than 1.