It is worth noting the advantage of belt transmission - smooth and silent operation. It does not require additional maintenance, such as lubrication, and protects components from overload due to slippage.
The working surface is the side edges, and the force is transmitted due to significant friction (jamming) belt into the pulley groove. Therefore, if you see that the belt is running on its bottom surface, it needs to be replaced - it will soon fail.
Weak belt tension causes slippage under load. This often becomes the cause of poor performance of the generator set. The belt is to blame, but we blame the generator. In this case, most often when towing the belt, "squeals" are heard. The operation of the water pump deteriorates, which can lead to engine overheating. But the latter happens much less frequently.
Excessive, strong belt tension leads to its rapid wear, increases the force on the water pump shaft bearings and the front generator bearing.
Reference:
Doubling the load on a bearing reduces its service life by 8 times. Therefore, excessive force should not be applied.
Normal tension is characterized by a certain deflection of approximately 8...10 mm when pressing with a finger with a force of 3...4 kg on the middle of the section between the water pump and the generator.
Belt tension is most often adjusted by moving the generator. To do this, loosen the nut and bolts securing the generator to the tension bar and tighten the belt using a lever. It's difficult to do this by hand.
If your alternator belt breaks while you are driving (he often brings the water pump too), this will be noticeable on the coolant temperature sensor - the temperature rises, and on the ammeter - it will show the battery discharge (the arrow will deviate towards "minus"). For such a case, we advise you to carry a spare one with you, and it is better not to let it get to this state: sometimes when the belt breaks, pieces of it get between the radiator and the fan, which leads to the destruction of the cooling tubes.
Modern cars use not only V-belts, but also toothed belts, which are used in synchronous transmissions on the drives of the high-pressure fuel pump (HPFP) and the gas distribution mechanism (GRM).
To correctly install the timing belts in these transmissions, it is necessary to align the corresponding marks on the toothed pulleys of the crankshaft and camshaft with the corresponding marks on the belt and the marks on the covers.
Since a broken timing belt during engine operation usually leads to significant damage to the timing belt and crank-piston group, they must be replaced in accordance with the manufacturer's recommendations (after about 80 thousand km).
If we consider a chain drive for the gas distribution mechanism, then there are more disadvantages than advantages.
Advantages: increased strength of a steel chain compared to a belt, which makes it possible to transmit greater power. But is that much power required to drive the timing belt? Of course not.
There are many disadvantages: wear of chain joints, additional loads, need for lubrication, wear of sprockets. But the main disadvantage is the increased noise level.