To remove the generator, disconnect the mass of the batteries, raise the cab of the KamAZ vehicle and disconnect the terminals "+", "-", B

Loosen the pinch bolt of the split support of the generator bracket, then unscrew the nut of the stud that secures the generator to the bracket, unscrew the bolt that secures the generator to the tension bar and remove the generator.

To install the generator on the bracket, insert the generator pin into the split support, and the bracket stud into the hole in the front cover of the generator, put on the spring washer and screw the nut onto the stud by hand.

Install the drive belts on the alternator pulley, ensuring that the axes of the grooves of the alternator pulley and the engine pulley coincide within ±1 mm.

Ensure the coincidence of the axes by moving the generator.

Put the spring washer on the bolt securing the generator to the tension bar, align the holes of the bar and the generator cover and screw in the bolt, setting the required tension of the drive belts by moving the generator.

KAMAZ vehicle alternator repair

Tighten the bolt securing the generator to the bar, tighten the nut securing the generator to the bracket stud, and tighten the split generator mount pinch bolt.

To prevent damage to the generator brackets, follow the tightening procedure for the fasteners.

Connect the "-", "+" and B leads.

When repairing a generator, it is recommended to eliminate malfunctions by replacing damaged parts and assembly units, and for this it is not always necessary to completely disassemble the generator. Repair of individual parts is allowed.

To disassemble the generator:

  • - unscrew the bolts securing the brush holder to the cover and remove the brush holder assembly with the voltage regulator;
  • - unscrew the screws securing the ball bearing cover;
  • - unscrew the clamping screws securing the generator cover;
  • - remove the cover from the side of the slip rings together with the stator;
  • - disconnect the phase leads of the stator winding from the leads of the rectifier unit and separate the stator;
  • - unscrew the pulley fastening nut, having previously fixed the rotor to one of the poles or holding it with a wrench, and remove the pulley;
  • - remove the fan, remove the segment key from the groove and remove the thrust sleeve;
  • - remove the cover from the drive side together with the ball bearing from the rotor shaft using a special puller (Fig. 2), using the threaded holes in the cover for this purpose;
  • - remove the ball bearing from the shaft;
  • - remove the rectifier block from the slip ring side of the cover.

alternator repair tool

Fig. 2. Puller

After disassembly, clean the parts and assembly units of the generator from dirt, metal, except for bearings and assembly units containing windings, insulating parts and semiconductor devices, degrease, rinse with gasoline and dry, and wipe the rest with a rag soaked in gasoline.

Inspect and replace mechanically damaged parts.

Cracks passing through the hole, hole wear of more than 17.02 mm and chipping of the pulley edges of more than 2 mm are not allowed on the pulley. Check the wear of the belt pulley groove.

A pulley is allowed to be installed if, when installed in the groove of control rollers with a diameter of 14 mm, the diameter measured by the rollers is at least 83.5 mm.

Remove the curvature of the fan blades by straightening and straightening.

If the hole in the cover mounting bracket on the slip ring side and the cover on the drive side is more than 10.3 mm worn or oval, ream the hole.

Worn mounting hole for the bearing in the cover on the side of the slip rings up to a diameter of more than 35.02 mm, and in the cover on the drive side - more than 47.05 mm, process to a size of 38.0 ... 38.05 mm and 50, 00... 50.05 mm, respectively, and then press in the repair ring while maintaining the same seat size for the bearing.

When assembling the alternator, to ensure the alignment of the alternator mounting holes on the engine, insert a tightly fitting rod into them before assembling. After fixing the tie bolts, remove the rod.

After assembly, check by hand the ease of rotation of the shaft and the technical condition of the generator.

Checking the excitation winding of the rotor

Check the condition of the winding with a tester (ohmmeter), while making sure that the tips of the measuring wires of the device are in contact with the contact rings of the rotor.

The resistance value must correspond to the value specified in the technical characteristics of the generator, if the winding does not have short-circuited turns.

If there is a break in the winding, then the ohmmeter needle does not deviate.

The health of the winding and the reliability of the fit of the brushes to the slip rings can be checked on the stand, not dismantling the generator.

When the voltage of the DC power supply is 28 V, connected to the winding plugs, the amount of current consumed must not exceed the value specified in the technical data of the generator.

If there is a break in the winding, then the ammeter needle will not deviate.

Connection diagram when checking the technical condition of the generator

Fig. 3. Connection diagram when checking the technical condition of the generator

Determine the short circuit of the excitation winding to ground with a test lamp or a voltmeter at a voltage of 220 ... 250 V. If there is no current for 1 minute, then the winding insulation is in good condition.

If a break is found in the excitation winding, inspect the places where the ends of the winding are soldered to the slip rings and, in case of desoldering, restore the broken connection.

If there is an open inside the winding or an inter-turn short or winding short to ground is found, replace the rotor.

Check the stator winding separately, after disassembling the generator, with the winding leads disconnected from the rectifier unit.

To determine a break in the phase winding of the stator, alternately connect two phases of the winding to the tester (ohmmeter) or through a test lamp to a current source with a voltage of 12-30 V.

In the event of a break in any of the windings, when it is connected to the terminals of the other two, the arrow of the tester (ohmmeter) does not deviate, and the control lamp does not light.

With a good phase winding, the ohmmeter readings must correspond to the values ​​\u200b\u200bspecified in the technical specification.

Check the interturn short circuit of the stator winding with a portable flaw detector model PDO-1.

Check the short circuit of the stator winding to ground due to mechanical or thermal damage to the insulation of the winding or leads with a test lamp at a voltage of 220-250 V by connecting one conductor to the stator core, and the other to one of the winding leads.

If the lamp does not light up, there is no short circuit.

Check the condition of the insulation of the winding wires, the insulation should not show signs of overheating.

If the phase output from the tip breaks, unwind one or two turns of the winding, install an insulating pipe and press or solder the tip.

Checking the technical condition of the generator

The cause of failures in the operation of the generator set may be a malfunction of the generator, a voltage regulator, or a violation of the electrical contact in the circuit of the power supply system.

Therefore, before proceeding with the test, make sure that the electrical contact of the wires is reliable at the terminals of the generator, voltage regulator, in the connecting blocks between the wire bundles and that the relay for disconnecting the excitation winding of the generator is in good condition.

Using a test lamp, check the presence of current in the excitation circuit.

Check the technical condition on a stand that allows you to change the generator rotor speed, current load and measure voltage, current and generator rotor speed.

Power the excitation winding from a DC source. Supply voltage 28 V.

Select measuring instruments so that the measured values ​​are within 30 ... 95% of the scale.

A device for measuring current must have an accuracy class of at least 1.5, and voltage - 1.0.