Questions related to accessory belt drive system which drives alternator, coolant pump, AC compressor and other accessories using the power drawn from the crank shaft pulley in automotive engines.

Accessory belt drive system drives the alternator, coolant pump, AC compressor and other accessories if present in a standard automotive engine. Additionally a tensioner system can be present in the drive layout for its smooth, jerk free operation.

Tensioner systems can be manual or automatic. A manual tensioner system, requires manual intervention to apply tension to the drive belt. It is achieved by changing the tensioner pulley position manually to increase the drive tension.

An automatic belt tensioner maintains the required belt tension without any external input and is designed using springs, friction elements or other hydraulic dampers. It helps in eliminating the belt deflections during the start and stop of the engine.