A car with a ZMZ-406 and ZMZ-405 engine is equipped with a generator 9422.3701 or 2502.3771
The generator is a three-phase synchronous electric machine with electromagnetic excitation and a built-in silicon diode rectifier.
The generator rotor is driven from the engine crankshaft pulley by a V-ribbed belt.
The stator and generator covers are held together with four screws.
The rotor shaft rotates in bearings mounted in covers.
The bearings are lubricated for their entire service life.
The rear bearing is pressed onto the rotor shaft.
The front bearing is installed on the inside of the front cover.
The back of the generator is covered with a plastic casing.
In the stator of the generator there are two three-phase windings made according to the "star" scheme and connected in parallel to each other.
The rectifier is a bridge circuit, it consists of six power limiting diodes or ordinary ones (on part of the generators).
They are pressed into two horseshoe-shaped aluminum holder plates.
On one of the plates there are also three additional diodes through which the excitation winding of the generator is powered after the engine is started.
The excitation winding of the generator is located on the rotor. The winding leads are soldered to two copper slip rings on the rotor shaft. Power is supplied to them through two carbon brushes.
The brush holder is structurally integrated with the voltage regulator.
The voltage regulator is non-separable, in case of failure it is replaced.
To protect the vehicle's electronic equipment from voltage pulses in the ignition system, as well as to reduce radio interference, a capacitor is installed between the "+" terminal and the "ground" of the generator.
The generator windings and the rectifier unit are cooled by the fan impeller through the windows in the covers.
Removing the generator
1. Disconnect the wire from the "negative" terminal of the battery.
2. Disconnect the wires from the three terminals of the generator.
3. Remove the alternator drive belt.
4. Unscrew the bolt 2 of the lower fastening of the alternator.
Unscrew the nut 1 of the upper fastening, while holding the bolt with a wrench
Loosen bolt 2, remove bolt 1 and remove the alternator
Generator disassembly
1. Clean the generator from dust and dirt.
2. Remove the back cover by releasing the three latches.
3. Unscrew the two screws 1 and remove the brush holder 2 with the voltage regulator assembly.
4. Unscrew the fastening screw and remove the capacitor installed under the brush holder.
Disconnect connector 1 with wire from capacitor 2. Unscrew four screws 3, bend the terminals 4 of the winding and remove the rectifier unit.
5. Unscrew the four coupling bolts 1 and remove the cover 2 from the side of the slip rings, passing the winding leads 3 through the holes.
6. Remove the stator with winding from the cover on the drive side.
7. Slightly clamp the anchor in a vice and unscrew the nut 1 of the pulley fastening. Using a puller, remove pulley 2
8. Press the armature out of the cover on the drive side.
9. If replacement is necessary, press the bearings off the armature shaft
Inspection and verification and generator details
1. Check the voltage regulator. Connect a 12 V test lamp to the brushes.
Submit a voltage of 12 V "+" to the terminal, and "-" to the "mass" of the brush holder. In this case, the control lamp should be on.
If the control lamp does not light up, the voltage regulator needs to be replaced.
2. Check the brushes below.
3. Inspect slip rings.
If scuffs, marks, scratches, signs of wear from brushes, etc. are found, the rings must be ground.
If damage to the rings cannot be removed with sandpaper, you can turn the rings on a lathe, removing the minimum layer of metal, and then grind.
After turning, check the runout of the rings using an indicator.
The maximum allowable runout is 0.08 mm. If the runout is greater than specified, replace the armature.
4. Check the resistance of the armature winding with an ohmmeter (tester) by connecting it to the contact rings. Armature resistance should be in the range of 2.35-2.6 ohms at 20 °C.
5. Check with a test lamp if the winding is shorted to the armature body.
To do this, turn on the control lamp in the 220 V AC mains (you can use a rechargeable battery and a 12 V lamp).
Connect one wire to the armature body, and the second wire in turn to each ring.
In both cases, the lamp must be off. If in at least one case the lamp is on, then a short circuit occurs and it is necessary to replace the armature or winding.
6. Check out the stator. On the inner surface of the stator there should be no traces of armature touching the stator.
Otherwise, replace the bearings of the armature shaft or the generator cover.
7. Check if there is a short circuit of the stator windings on the case.
To do this, turn on the control lamp in the 220 V AC mains (you can use a rechargeable battery and a 12 V lamp).
Connect the lamp to the stator winding terminal, and the wire from the current source to the stator housing, while the lamp should not light.
If the lamp is on, this indicates that there is a short circuit in the winding, therefore, it is necessary to replace the stator or winding.
8. Check for an open in the stator winding. To do this, turn on the test lamp in a 220 V AC network (you can use a rechargeable battery and a 12 V lamp).
Alternately connect a test lamp between all winding leads.
In all three cases, the lamp should be on.
If at least in one case the lamp does not light, then there is a break in the winding and the stator or winding needs to be replaced.
9. Check the diodes of the rectifier unit using a 12 V test lamp and a battery.
To check the positive diodes 1, connect the “-” of the battery through a test lamp to the positive plate of the rectifier unit, and connect the wire coming from the “+” of the battery in turn to the contact of each positive diode (red diagram).
In each case, the lamp must be lit. Then reverse the polarity, i.e. Connect the “+” of the battery through a test lamp to the “positive” plate of the block, and connect the wire coming from the “-” of the battery to the contact of each diode in turn, while the lamp should not light in each case.
To check the negative diodes 2, perform the same steps (blue diagram). If the above conditions are not met, then the rectifier unit must be replaced.
10. Inspect the generator covers. If cracks are found, especially in the places where the generator is attached, the covers must be replaced.
Measure the diameters of the bearing seats. The diameter in the cover on the side of the slip rings should be (35.0 ± 0.012) mm, on the side of the drive - 47.0 + 0.027 mm.
Lids To be replaced if the diameters do not fall within the specified limits.
11. Check the ease of rotation of the bearings. If during their rotation there is play between the rings, rolling or jamming of the rolling elements, such bearings must be replaced.
It is also necessary to replace bearings with damaged protective rings or traces of grease leakage.
Assemble the generator in the reverse order of disassembly.
Install the generator in the reverse order of removal. After installing the generator, adjust the tension of the generator drive belt
Checking and replacing the generator brushes
Disconnect the wire from the "negative" terminal of the battery
Disconnect the wires from the three terminals of the generator.
Remove the back cover by depressing the three latches.
Unscrew the two screws 1 and remove the brush holder 2 with the voltage regulator assembly.
Check the value "a" of the protrusion of the brushes from the brush holder. If the value "a" of the protrusion of the brushes in the free state is less than 4.5 mm, it is necessary to replace the brush holder assembly
Check the ease of movement of the brushes in the brush holder. If the brushes are stuck, the brush holder assembly must be replaced. Brushes with chips, cracks or other defects are also subject to replacement.