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 belt tensioner is provided for mounting on a mounting surface of a structure. The tensioner comprises a body, which defines a cavity, and a drain hole that is in communication with the cavity. The drain hole is located on the body so as to be facing the mounting surface of the structure when the tensioner is mounted on the structure. In this manner it is more difficult for contaminants to enter the body than to exit the body.

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 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.