Engine Accessory Drive With Belt Tensioner and Same Plane Idler

A belt tensioner for a starter generator drive is provided. The belt tensioner comprises a carrier having a pivot defining a first pivot axis at a first end and a carrier arm extending from the pivot to terminate in a second end. An idler pulley is rotatably mounted to the carrier for rotation about the first pivot axis and a tensioner pulley is rotatably mounted to the carrier at the second end of the carrier arm for rotation about a second axis. The second axis extends parallel to and is arcuately moveable relative to, the first pivot axis. A tensioner is in communication with the second end of the carrier arm for biasing the carrier arm and the tensioner pulley against a drive belt for tensioning the drive belt engaged by the idler pulley and the tensioner pulley.