Triangle of engine crankshaft pulley by power supply. Triangle belt pulley engaged in all kinds of engine parts, make them run. Most cars on the belt driving element including the power steering pump, generator and water pump. Some of the motor is driven by belt air pump and air conditioning compressor. Need to replace the broken v-belts, belt there is not enough for a long time of repair is possible. This article by synchronous belt wheel arc-gear synchronous belt steel original, reproduced please indicate the copyright: http://www. lilainuo。 com