belt tensioners is a general term of the auto part that makes the belt move and still tensioned.
It is an engine part with components of bush, bolts, screws, caps etc. Belt tensioners mostly used on Automotives, however, they are used on all belt drive systems such as; A/C engines, elevators, washing machines etc.
Belt tensioners are divided by two in automotive engines. Alternator belt tensioners and timing belt tensioners. ABA Automotive has more than 1000 range on timing, altarnator and other kinds of belt tensioners. A belt tensioner type varies with its belt. For example, a timing belt tensioner has tooth on its surface due to the belt is with tooth. On the other hand, altarnator belt tensioner has a straight surface related to its belt again.
Furthermore, those are divided two by their objectives as well. Automotic belt tensioners and idlers. Automotic belt tensioners are the main part in the belt drive system that tensions the belt. Automatic tensioners are most likely heavier, bigger and more expensive than idlers. The reason is automotic one have extra components of spring, housing, etc. On the other hand, idlers are smaller and lighter parts of the belt drive system. Their main goal is to shape the belt drice system and maximize the torque of the altarnator.
A product has two main components. One is the bearing that makes the part turn. Second is the pulley, which is the outer part of the bearing. A pulley is the body part of a belt tensioner. A pulley can be metal, sheet metal, plastic, sinter etc. Depanding on a pulleys raw material machining process diverse to shape the material.For manufacturing, ABA Automotive use plastic injection machines for plastic pulleys, CNC machinces for metal pulleys, hydrolic presses for sheet metal pulleys. In some cases pulleys might need coating. Coating process avoids a pulley from rusting and dust.