A tumbling (vibratory finishing) machine is an open-topped tub or bowl mounted on springs, usually lined with polyurethane. Vibratory action is created either by a vibratory motor attached to the bottom of the container, by a shaft or shafts with eccentric loads driven by a standard motor, or by a system of electromagnets.
Bowl vibrators are round bowl shaped and have a container mounted on springs. Vibratory action is imparted to the bowl by eccentric weights mounted on a vertical shaft at the center of the bowl. When activated, a spiral motion is imparted to the mass of parts and media. The major advantage of bowl vibrators is that an integral separation system can be incorporated. To separate parts from media, a dam is placed in the channel so that parts and media are forced up and over. At the top of the dam is a screen over which parts and media pass. Media fall through the screen back into the vibrator bowl. Parts are deflected off the screen into a collection hopper or conveyor.