fan clutch

The fan clutch is a device controlling the engagement of the EC fan. A valve inside the clutch regulates the flow of a special silicon oil. The oil transmits the engine's torque thus, rotating the fan. The fan clutch can be driven by a belt and pulley or directly by the engine when mounted on the engine's crankshaft.

The viscous coupling is often found in all-wheel-drive vehicles. It is commonly used to link the back wheels to the front wheels so that when one set of wheels starts to slip, torque will be transferred to the other set. Mechanically, it works similarly to the torque converter that transfers power from an engine into an automatic transmission. The viscous coupling has two sets of plates inside a sealed housing that is filled with a thick fluid. One set of plates is connected to each output shaft. Under normal conditions, both sets of plates and the viscous fluid spin at the same speed.

Viscous fan couplings are used on cars with inline engine positions, mainly rear wheel drive. Location: Between the water pump pulley and the radiator. Function: · Controls fan speeds to aid engine cooling. · Aids in the efficiency of the engine by engaging the fan, when necessary.