Generator VAZ 2108: installation, connection, circuit

What is the VAZ 2108 generator and where it is installed, every owner of this car knows. But hardly everyone will be able to say on what principles he works, and also list all the basic elements of which he is composed. It is worth noting that the generator and simple DC motor are very similar in design. They are not just similar, they are identical devices. The only difference is that one produces electricity, and the other - consumes. But this difference does not end, you need to consider in more detail the generator system to find them all.

Rotor and its winding

We can say that the basis of the generator is its rotor. It has a winding made of copper wire. The rotor winding is supplied with a constant voltage from the battery. The principle of operation of any generator set consists in the fact that it is necessary to have two main components - motion and a constant magnetic field. How can you create the latter? Either by installing powerful magnets, or by winding the wire on the magnetic circuit. The first option disappears immediately, since the cost of, for example, niodim magnets, which are ideal for this purpose, is too high. The VAZ 2108 generator circuit includes a winding on the rotor.

It is much cheaper and easier to wind the copper cable. The thing is that when a voltage is applied to such a winding, the magnetic field is generated. And it is the greater, the higher the field strength. Consequently, as the characteristics of the supply voltage increase, the field also increases. It is worth noting that the copper wire is many times cheaper than niodim magnets, and its service life is very high. Electric damage to him is almost impossible, as well as mechanical. The latter - except that with careless handling during the repair.

Stator winding

The VAZ 2108 generator has a rather massive stator winding, since it uses a wire with a large cross section. It is with his help that electricity is generated. The wire is wound evenly over the entire inner surface of the stator in specially selected for this purpose grooves in the magnetic circuit. Separately it is necessary to talk about the latter. The middle part, the stator of the generator, consists of a set of thin metal plates tightly pressed together. Often they are cooked on the outside so that no stratification occurs.

In fact, of course, the stator winding of an automobile generator consists of three absolutely equal parts. The reason for the special way of generating electricity is to obtain a three-phase alternating voltage, which will then be rectified. But this process will be described below. In other words, the stator of an automobile generator is very similar to a similar element of an induction motor. Even the connection of the windings is done in such a precise manner. The connection of the VAZ 2108 generator, or more precisely, its winding, is made according to the "star" scheme.

Covers and bearings

In the front and back covers, which are attached to the stator housing, there are bearings. They are necessary to ensure the normal operation of the generator. With their help, the rotor rotates more freely, but most importantly - it is aligned strictly along the axis of rotation. Consequently, the rotor magnetic circuit does not catch the stator winding during operation. The covers are made of light metal - aluminum, which performs several functions at once.

First, aluminum absorbs well and gives off heat. A generator VAZ 2108 is very hot during operation. Secondly, aluminum has a low weight, which makes it possible to facilitate the entire structure. In addition, an impeller is mounted on the generator, in front of it. During the rotation of the rotor, it generates a flow of air, which enters the body of the mechanism. This results in additional cooling.

Drive of the generator

For the drive, a VAZ 2108 generator belt is used . It should be noted that this car model was produced only with a carburetor injection system, so the belt was mounted on it on a wedge-shaped system. On the newer cars of the ninth and tenth families, the fuel system in which the injector type, put a slightly different belt. It is more like the one driven by the timing mechanism, but instead of the teeth on the inside, it has streamlets.

Rectifier bridge

It is with the help of this device that the conversion of the alternating voltage into a constant voltage occurs. After all, you know that there is plus and minus in the vehicle's on-board network. And some can even say that the VAZ 2108 generates 12 volts. However, there will be someone who can specify a little, mentioning that on some cars in the onboard network 24 volts. But on the eights, of course, only 12, this is quite enough. So, in the on-board network plus and minus, and at the output of the winding of the generator three phases. What to do?

For this purpose, a rectifying unit is used. It consists of three pairs of semiconductor diodes. It turns out that the two diodes straighten each phase coming from the stator winding. And the output of this device after the conversion is a constant voltage. Also, the VAZ 2108 generator circuit includes a capacitor that cuts off all the AC current remaining after the rectifier unit. But the trouble is in the other - depending on what rotational speed is at the rotor, there is a change in the output voltage. How can we get rid of this?

Voltage regulator

The problem is posed, it must be solved. And it's not difficult to do this if you just stabilize the voltage, which energizes the generator rotor winding. The thing is that now, no matter what voltage there is at the output of a couple of power sources - the generator and the battery, only the stable one is supplied to the excitation winding (rotor). On VAZ 2108 vehicles, the generator voltage is on the order of 12.5-13.8 Volts. Consequently, the magnetic field will always be the same, regardless of the rotational speed of the rotor. And if this is so, then the stator winding will also be stable.

How to dismantle the generator

To replace the VAZ 2108 generator as quickly as possible, you will need a penetrating lubricant. The reason for its necessity lies in the lowest anchorage. The bolt is located at the level of the engine sump. Unfortunately, not always the machine has a mudguard. And even if it is, the moisture and dust fall on the threaded connection. Therefore, it must be treated abundantly with penetrating lubricant, after which it should be allowed to settle for at least half an hour. This time is enough to make all the rust and dirt on the carving soaked.

If the generator has not been removed for a long time, it is better to treat the upper nut with the same lubricant. After such a little preparation, unscrew the nut completely from the upper stud. Using a cap and a socket wrench, unscrew the lower bolt. It is desirable to carry out this work from the bottom of the car, so it will be much more convenient. It is possible that the bolt will tighten out. In order to pull it out, you need to use a bolt or pin of a slightly smaller diameter. Note that all these operations must be carried out with the battery disconnected. All the wires that connected the VAZ 2108 generator are also required to be disconnected.

How to install a new generator

Installation of the new generator is carried out in the reverse order. Take a good look at the condition of the lower bolt. If it has damaged threads, it is better to replace it. You will find it easier to repair the generator afterwards. Pay special attention to the belt tension when installing. If it is not stretched enough, your battery will not charge properly. And if you tighten the belt, the bearing will collapse in the front cover. In the end, you get an unpleasant whistle when the engine is running. And the reason for this - the appearance of play in the bearing. Installation of the generator on the VAZ 2108 should be done in such a way that even the slightest distortions do not arise.

Conclusion

In conclusion, I would like to note that only timely maintenance will ensure a normal and stable operation of the generating set. To replace the voltage regulator, which is combined into eight knots in one knot with brushes, it is necessary in time. Do not wait until the moment when the power of the rotor winding is lost because of the complete destruction of the brushes. Only under these conditions the VAZ-2108 generator will not fail and will always give out normal charging for the battery.