Automatic tensioners are mechanical devices used in various machines to maintain the correct tension in belts or chains. They help ensure that these components operate smoothly and efficiently by adjusting automatically to changes in tension caused by wear or temperature fluctuations. This prevents slippage and prolongs the life of the belt or chain. These tensioners typically consist of a spring-loaded arm that applies pressure to the belt or chain. As the tension changes, the arm moves to compensate, keeping the system properly adjusted without the need for manual intervention. This feature is especially useful in automotive applications, where consistent performance is crucial.