ELECTRONICALLY CONTROLLED ACCESSORY DRIVE SYSTEM FOR AN AUTOMOTIVE ENGINE

摘要

An electronically controlled accessory drive system for an automotive engine includes a drive pulley attached to an output shaft of the engine and a flexible drivebelt for connecting the drive pulley with driven pulleys. A tensioner maintains the drivebelt in contact with each of the drive and driven pulleys. The tensioner includes an arm which is rotatably mounted to the engine, and has a wheel for contacting the drivebelt. The wheel is urged into contact with the drivebelt by the arm, with the tensioner further including a governor for controlling rotational motion of the arm, with the arm being able to rotate freely in the direction toward the drivebelt, with the governor resisting motion of the arm in the direction in which tension in the drivebelt is decreased. Motion of the governor is controlled by an electronic controller which operates a magnetic coil disposed about a fluid passage through which a magnetorheological fluid must pass as the tensioner arm rotates.