Abstract: A first belt tensioner includes an arm, spring case, coil spring, and arm plate. The arm is adapted to support an idler pulley and has a hook portion. The spring case is disposed in the arm and has a first spring seat. The spring is disposed in the spring case. The arm plate has a second spring seat. The spring is longitudinally compressed between the arm plate and the spring case. The spring is in torsion with the end portions of the spring seated against a corresponding spring seat and with the arm plate rotationally positioned under the hook portion. A method for assembling the first belt tensioner includes using the arm plate to longitudinally compress the spring and rotating the arm plate. A second belt tensioner includes an arm, spring case, coil spring, arm plate, and pivot bushing.

Abstract: A belt tensioner includes an arm, a spring case, and a helical spring having inwardly projecting first and second end portions. Another belt tensioner includes a spring, an arm, a spring case, and a pivot bushing surrounding the spring. An additional belt tensioner includes an idler pulley having a bearing with a mounting hole and includes an arm having a post. The post is positioned in the mounting hole, and an annular rim of the post is deformed radially outward and over the bearing. A method for manufacturing an arm and a spring case of a belt-tensioner includes obtaining a belt-tensioner-arm casting mold including a first section and a second section and obtaining a belt-tensioner-spring-case casting mold including a first segment and a second segment.

Abstract: A vibration damper and/or isolator for a rotating shaft is provided comprising a hub, an inertia element, a magneto-rheological elastic element interposed between the hub and the inertia element to non-rigidly couple the inertia element to the hub, and an electromagnet operable to produce a magnetic field across the elastic element when energized. The magneto-rheological elastic element, which may comprise a composite of magnetic-responsive particles dispersed within an elastic material possesses a variable shear modulus that is dependent, at least in part, on the strength of a magnetic field applied to the elastic element.

Abstract: A vibration damper for controlling the torsional and bending vibrations in a rotating shaft is provided. The vibration damper includes a hub, an inertia element, and an elastic element that possess a first shear modulus in a first direction and a second shear modulus in a second direction. The hub is adapted to be coupled to the shaft for rotational movement. The inertia element is concentric with the hub and has a mass. The elastic element is adapted to non-rigidly couple the hub and the inertia element. The elastic element may be a non-isotropic composite material having a plurality of fibers dispersed therein.