Abstract
This paper presents a discussion of the development of a viscous fan clutch with continuous linear variable speed control function for engine cooling system to reduce cooling fan noise and improve the overall fuel efficiency of the engine. By applying a fan drive clutch having a continuous speed control device providing the proper cooling air flow rate proportional to engine cooling load, it can be expected that the fan driving horsepower can be reduced and also fan noise and vibration can be reduced significantly. In the present study it is shown that a viscous fluid fan clutch, for small diesel engines (1 to 3.5 ton class), having a linear variable speed control function corresponding to cooling load and low temperature hysteresis has been developed.