| 摘要 |
A temperature-sensing, variable-speed fan drive with a fluid coupling filled with working fluid, for cooling two stacked heat exchangers, namely an engine cooling-system radiator and an air-conditioner condenser located in front of the radiator, comprises a partition plate dividing the internal space of a fan housing into a reservoir chamber and a working chamber, and two different communication ports, each formed in the partition plate to communicate the reservoir chamber with the working chamber. In addition to a first valve mechanism which adjusts the opening of one of the two communication ports in response to atmospheric temperature in the circumference of the housing, a second valve mechanism is provided to adjust the opening of the other of the two communication ports in response to a refrigerant pressure in the air-conditioner condenser. The second valve mechanism includes a valve portion which opens and closes the other communication port, a push rod associated with the valve portion, and an actuator which shifts the push rod from inactive to active in response to a control signal. Also provided is a fan-drive controller which outputs the control signal to the actuator when the refrigerant pressure in the air-conditioner condenser exceeds the predetermined threshold value.
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