Home / News / Industry News / What is A Drive Belt

What is A Drive Belt


In this article, let's talk about automotive Drive Belt […]

In this article, let's talk about automotive Drive Belt. Sometimes they have to screech and squeal before we'll take notice. That horrible noise is usually the last sign that your drive belt will give you before it breaks.

Your engine's drive belts basically "drive" accessories that are either bolted to or hung via brackets to your engine. Drive belts also turn that little electric generator called an alternator. And they "give life" to your air conditioner's compressor. In some cases, a drive belt might be responsible to turning a cooling fan or even your water pump. All of these devices are essentially powered by the turning force of your engine via a belt of some kind.

There are several different types of belts that are used on automobiles and motorcycles. We'll discuss the serpentine, the V-belt, and the toothed V-belt.

The serpentine belt is the most common type of belt used on most cars and trucks. These belts are named "serpentine" because, you guessed it, they are long and their routing through accessories is "snake-like". This type of drive belt usually powers a lot of accessories. They were designed to save space by connecting most of the accessories, and thereby eliminating the need to stack or stagger the accessories behind or in front of one another.

A serpentine belt usually is ribbed on one side and flat on the other. This helps the belt stay in place. Typically, the ribbed side comes in contact with the ribbed pulley of an accessory such as your alternator. The flat side comes in contact with a smooth pulley such as an idler pulley.

The V-belt is still used in modern automobiles. It is called a V-belt because its cross section view resembles the letter V. V-belts typically are used to power a single accessory such as your vehicle's air conditioning compressor. They are rather simple and fit into a V-shaped pulley. Sometimes they are used in pairs on trucks or other powerful vehicles.

The toothed V-belt is used in high torque applications. Torque is essentially "turning force". They are also used on powerful engines and on motorcycles. This type of belt has teeth that fit into the grooves of a toothed pulley.

Pulleys basically allow a drive belt to change direction as it routes to another accessory. All belts must operate under a certain amount of tension or tightness to properly turn an accessory without slipping. How is the tension maintained? With an idler/tensioner pulley of course! This type of pulley is attached to a large and powerful spring or a strut type system. These pulleys create tension on the belt by pushing down on the belt so that it tightens. This causes tension across the entire length of the belt, allowing it to "grip" the accessory pulleys. This same thing would happen if you were to push down on a belt at the point where your hand is mid-way between two pulleys or accessories. Maintaining your pulleys is just as important as maintaining your drive belts.