Uses of a Pulley & Belt

by Mary Lougee

There are four items in vehicles that work on a belt and pulley system. The engine turns the pulleys of internal or external parts of components like the alternator, air conditioner compressor, power steering pump and water pump, making them operate correctly.


The alternator in your vehicle uses a belt and pulley system to operate. The alternator pulley turns round to supply energy to run the engine and other electrical components in a car. The headlights, interior lights, dash lights, taillights, stop lights and blinkers all work off the energy that the alternator produces. This also includes the windshield wipers, radio and all electrical windows and door locks in a vehicle.

A/C Compressor

The air conditioner (A/C) compressor uses a pulley and belt system to work your A/C system. The belt turns on the pulley on the compressor so that return air is compressed and passed through the condenser along with the refrigerant to cool the incoming air into your car. The air in the car is then recirculated back through the system to cool it again.

Power Steering Pump

The power steering pump in a vehicle uses a belt and pulley system to circulate power steering fluid to the steering mechanism. The power steering pump draws the fluid out of the reservoir and through the power steering feed hose. The power steering pump circulates the fluid back to the reservoir through the return feed hose and this process repeats continuously. The power steering pump assists you in turning your steering wheel with ease.

Water Pump

The engine in a vehicle uses water and antifreeze to cool itself properly. The water and antifreeze are in the radiator when a vehicle is not running. When you start the engine the belt turns on the water pump pulley and circulates the water and antifreeze through a hose into the water pump so that it can enter the engine to cool it. The water recirculates through the water pump back into a return water hose and to the radiator where the cooling fan between the water pump and radiator cools the liquid inside the radiator. This process is continuous as long as the engine is running.

About the Author

Mary Lougee has been writing for over 10 years. She holds a Bachelor's Degree with a major in Management and a double minor in accounting and computer science. She loves writing about careers for busy families as well as family oriented planning, meals and activities for all ages.

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