| 摘要 |
A circumferentially supported fan assembly for drawing cooling air through a radiator of a vehicle is described. The fan includes a fan ring extending circumferentially around the periphery of the fan, the blades of the fan extending from a central region to the fan ring. The entire weight of the fan is borne by a fan support assembly which extends around the periphery of the fan ring, outside the path of air flowing through the fan. The fan is the rotor of an electrically driven motor. A rotor flange of the fan ring extends transverse to the axis of the rotation of the fan, providing a greater torque advantage for the motor. An electrical control circuit selectively controls the speed of the fan to maintain the liquid temperature of the radiator below a selected threshold value. As additional cooling is required, the electronic controller gradually and smoothly increases the power drawn from the engine to turn the fan to increase its speed towards a selected speed. The air permeability of the fan when freewheeling is significantly increased because no central shaft or support structure blocks the airflow through the fan. |
