Spur gears or straight-cut gears are the simplest types of gear. They consist of a cylinder or disk with teeth projecting radially. Though the teeth are not straight-sided (but usually of special form to achieve a constant drive ratio, mainly involute but less commonly cycloidal), the edge of each tooth is straight and aligned parallel to the axis of rotation.
DWG (AutoCAD, filesize: 806 KB), SLDPRT (SolidWorks, filesize: 327 KB), PDF (PDF, filesize: 70.7 KB)