A alternator clutch pulley is the mechanical link between the alternator and the engine output crankshaft pulley. The pulley
drives the alternator which allows the battery to be recharged. The Overrunning Alternator Pulley (OAP), also called the freewheel
pulley, is a spare part of the complete alternator. It is composed of a pulley with an outside diameter suitable for fitting a
“poly-V” belt (drive belt), a one-way clutch unit with bearing supports, an inner ring, two seals and an end cover in plastic.
The Freewheel Pulley is used to:
1.Protect belt drive system by filtering engine torsional vibrations to improve the belt drive longevity
2.Ensure belt drive N.V.H. (Noise-Vibration-Harshness) for optimum driving comfort
3.Stop friction losses caused by belt slippage
4.Allow the alternator rotor to turn in freewheel mode when the engine is slowing down or stopping for maximum system efficiency,fuel savings and CO2 emissions reduction .