When gear meet gear

Gear transmission is the function of dynamic and movement, this would mean that in a mechanical system of a single gear is meaningless, should at least have two. The common situation is such, a big gear and a pinion installation together, this call meshing, like teeth as well bite together, and another carrying another smooth rotation. Must be a brought another turn, i.e. one is active, called active wheel, one is passive, called driven pulley. If the two are active, affirmation is lose-lose game. If the two are not actively, they are just two quietness of parts. Well, why should one big one small? As big as is possible, and running status will be quite good, but in the mechanical system applied meaning is not very big.
Secondly, comparatively big gear than small gear turns lap is small, so small gear is tired of that one, at this time will be considerate of the small. In making time to give a small gear versus the good material, choose of the more advanced technology. Only in this way, in the whole cooperation period can cooperate well two gear almost at the same time, eventually scrap. Because it is very important, at any time, we are not advocate midway gear replacement of mesh object. Because every change once, gear are through painful period, we don't want to gear limited life is wasted in break-in.