Final answer:
Alternators with clutches in the pulley include overrunning alternator decouplers (OADs), which help reduce stress and wear on the engine's accessory drive system.
Step-by-step explanation:
Alternators that have clutches in the pulley also have overrunning alternator decouplers (OADs) or one-way clutches. These components allow the pulley to decouple from the alternator's rotor shaft when the engine RPM decreases. This function helps to reduce the load on the belt-driven accessories, minimizing noise and vibration, and potentially extending the life of the accessory drive belt. The overrunning alternator decoupler is especially beneficial during deceleration or when the engine is shut off, as it isolates the inertia of the alternator from the rest of the drive system.