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What are Pulleys?

Cars have 2 belt pulley styles, idler, and tensioner. Most cars only have one of each kind, but there are others with more than one idler pulley. The idler and tensioner pulleys look the same and even operate the same way. We avoid the often-annoying vibration of the engine drive belt that usually happens when the drive belt mechanism becomes too slack. The distinction between the two is that the idler pulley is mounted on a fixed frame while an adjustable unit fits the tensioner pulley.

Specifically, the idler pulley provides a smoothly and efficiently rotating point for the car’s engine belt drive to move and loop around, preventing unnecessary slack. This also helps in increasing the tension on the belt, allowing the engine to deliver power to the different accessories in a more efficient manner.

The idler pulley also functions in the prevention of flat belt drive slippage. As the name implies, a flat belt is one that has a relatively flat surface or the entire length of the belt. The pulley prevents this belt from ever slipping out of its position. The idler pulley may have a smooth outer wall, but the edges typically have retainers while some may have a middle groove to keep the drive belt in place.

Specifically, the idler pulley provides a smoothly and efficiently rotating point for the car’s engine belt drive to move and loop around, preventing unnecessary slack. This also helps in increasing the tension on the belt, allowing the engine to deliver power to the different accessories in a more efficient manner.

Why Aftermarket Ones are Better?

  • They are used to take up the slack, change the direction of transmission, or provide clutching action.
  • . Aftermarket pulley are rollers that do not produce any mechanical advantage, nor transmit power to a shaft.
  • They are more ideal hoisting equipment. Aftermarket ones can be used to improve belt drive performance.
  • Also, they can be used to reduce more belt vibration by supporting a segment of the belt that is prone to vibration/oscillation. Most of them are used in car engines for more positive clutching action by running the idler pulley on the slack side of the flat-belt drive from the engine to transmission.