Round belts

        The round belt is a green synthetic belt of homogenous structure with high elasticity and flexibility. It is provided in small diameters and large length (like the wire), so it can be easily and quickly converted to endless belt in machine shop, with simple and low cost tools. Using heating with a fixture that holds both ends in proper position, we can weld both ends and create the endless belt without a noticeable joint. The last characteristic assures quiet, smooth and uniform power transmission. In case of drive overpower the round belt slides easily on the pulley, protecting this way the machinery from damages. Its round shape makes it ideal for design solutions with small dimensions.

Another use and probably the one with many applications is handling light weighted items. In packaging we are dealing with many problems when we need to transfer and guide light parts (plastics, papers or combination of them) in line. Before assembling or packaging the items, they must be placed in a buffer line in order to maintain a continuous flow to the packaging or assembling machinery. The conveyors made from round belt have the advantage of producing only a small amount of friction force with a single item they are conveying. This force is capable for transferring the item, and the same time will not cause any damage (burns, dirt) if we immobilize it (the belt keeps moving) for a little time. This is useful because this way we can pick one or more of the items and pack or assemble them, and when the picker returns for the next group this will be already in place. Many plastic items with a weight only of a few grams each, when are transferred in a round belt conveyor of 2.5 meters they can produce even 3 to 4 kilograms of thrust to the last item at the end of the conveyor. This thrust assures that the last item will stay in place, and the previous items can be checked or measured easily. The round belt due to its shape can easily change direction. This allows the designer to choose whichever direction for returning to the driving pulley. Due to the material flexibility the conveyor doesn’t require a tensioning mechanism. Instead of a tensioner the belt can be welded with a length less than 8-10%, and afterwards during assembly we can tension it in order to be placed inside the pulleys.
For long conveyors we use many pulleys (about 200 mm each for small diameters) in order to simply support the belt (only few of them are returning and orienting the belt to the driving pulley). These pulley configurations are very simple, they are composed by a threaded shaft, a ball bearing and the pulley (see figure). A proper washer ensures the correct distance of the pulley-round belt from the mounting plate.