We remove the generator for inspection and repair
Removing and disassembling the generator
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.
5. Loosen bolt 2, remove bolt 1 and remove alternator.
- 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 winding leads 4 and remove the rectifier unit.
- 5. Unscrew the four tie bolts 1 and remove the cover 2 from the side of the slip rings, passing the leads 3 of the winding 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.
Press the armature out of the cover on the drive side.
If replacement is necessary, press the bearings off the armature shaft
Inspection and verification
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.
See below for checking the brushes.
3. Check 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 slip rings.
Armature resistance should be between 2.35 and 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 - in turn for each ring.
In both cases, the lamp must be off. If at least in one case the lamp is on, then a short circuit occurs and it is necessary to replace the armature or winding.
Inspect 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 housing (Fig. 15).
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.
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 lit. If at least in one case the lamp does not light up, then there is a break in the winding and the stator or winding must be replaced.
Check the diodes of the rectifier unit (Fig. 17) 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 on.
Then reverse the polarity, i.e. Connect the “+” of the battery through a control lamp to the “positive” plate of the block, and connect the wire coming from 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.
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 drive side - 47.0 + 0.027 mm. Covers must be replaced if the diameters do not fall within the specified limits.
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.
Assembly
Assemble the generator in the reverse order of disassembly.
Installation
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.
2. Disconnect the wires from the three terminals of the generator.
- 3. Remove the back cover by releasing the three latches.
- 4. Unscrew the two screws 1 and remove the brush holder 2 with the voltage regulator assembly.
5. 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.