There are three main types of pulleys in a car: cam pulley, crank pulley, and accessories pulley. These pulleys connect to each other and are practically triggered by the crank pulley, which serves as the main pulley in every vehicle. But how many pulleys does a car have?
The total number of pulleys you may find in a car depends on the number of accessories installed in the car. A vehicle with more interior accessories would have more pulleys. Car pulleys are connected using serpentine belts, which all have to work for your car to drive.
This article explains how the various pulleys in modern works work.
How Many Pulleys Does A Car Have?
There can be tens of pulleys in a car, depending on the accessories and features installed in the car. However, there are just three types of pulleys found in modern vehicles; the cam pulley, crank pulley, and accessories. Now, there can be many accessory pulleys, but there’s only one crank pulley and one cam pulley.
The crank pulley, as the name implies, is connected to the crankshaft of the vehicle, and it is mainly the “chief pulley” in the sense that it is the pulley that drives all other pulleys to work.
Some other notable pulleys in a car include the air conditioning pulley, idler pulley (which is not connected to any peripherals), alternator pulley, and the “harmonic balancer.”
Pulleys in a car are connected using serpentine belts or V-belts. These belts turn to move the pulleys and power the connected peripherals or accessories.
All car pulleys are made using high-grade metals capable of withstanding extremely high temperatures on a regular basis. Notwithstanding, pulleys can break down if there’s a high-impact collision.
How Do Car Pulleys Work?
Car pulleys work in a pretty simple way; the main pulley, which is the crank pulley, activates and pushes the rest of the pulleys to work. A pulley cannot work if the connected belt does not move in rotary motion.
When an accessory pulley rotates due to the drive belt motion, it triggers the corresponding accessory to activate. For example, when the air conditioning pulley rotates, it powers the AC units inside the car; similarly, when the alternator pulley rotates, it converts magnetic force from the engine into electricity and powers the alternator to charge the car’s battery.
There’s also a dedicated pulley that drives the power steering pump; this pulley pressurizes the power steering fluid and circulates across the many connected components, making it easy for the driver to steer the car without any issues.
Once you start a car, virtually all the pulleys start working, but some of them require a manual push to actually activate (ex., the AC pulley).
The idler and tensioner pulleys work differently; they are not connected to any peripherals or accessories, which means they do not power anything in the car; these pulleys are often installed as part of an accessory pulley or to complete a complex belt path.
Idler pulleys spin freely when activated, while, in some cases, tensioner pulleys are installed to maintain high tension on the serpentine belts connecting different pulleys.
Frequently Asked Questions
What Is a Crank Pulley?
Quite easy to detect, the crank pulley is the crankshaft pulley. It drives the crankshaft and passes power onto several other pulleys that may be available in a vehicle. You’d usually find the crank pulley installed at the end of the crankshaft system. It is the base and most important pulley in any vehicle.
What is a Cam Pulley?
Put simply, the cam pulley controls the rate of rotation of the camshaft in every vehicle. It is installed as part of the vehicle’s timing system to precisely determine when to open the poppet valves for air to go into the engine’s combustion chambers. This pulley is connected to the crankshaft using the timing chain and rotates synchronicity with the crankshaft.
What is an Accessory Pulley?
An accessory pulley is a type of pulley that drives a particular peripheral of the engine or accessory installed in the car. Examples of this type of pulley include the AC pulley and alternator pulley. There can be more than four (4) accessory pulleys in a car, depending on how the car is built.
How Many Idler Pulleys Does A Car Have?
There is mostly one idler pulley and also one tensioner pulley. These pulleys do not carry out any work; they are there are part of a complex serpentine belt path or help increase belt tension for the proper effectiveness of other pulleys.
So, how many pulleys does a car have? Most cars have five pulleys, the crank pulley, cam pulley, AC pulley, alternator pulley, and one idler pulley. However, there may be more pulleys, depending on how the car is built and the purpose it is meant to serve.