<div class="htmlview paragraph">This paper describes the construction, characteristics and capabilities of a compact automatic tensioner for timing belts that was recently developed by NSK.</div> <div class="htmlview paragraph">This auto-tensioner differs from conventional ones having separate actuators. By incorporating the damping mechanism inside the bearing, a compact size nearly equal to that of fixed type tensioners was achieved. The damper is a multi-disc viscous type that uses high viscosity silicone oil.</div>