24:10. Generator
Cars equip with generators of alternating current. Depending on model and electric equipment installed on the car generators of various power can be installed. At installation of additional electric equipment check that there was enough power of the generator for food of the new consumer.
The drive of the generator is carried out by a poliklinovy belt from a bent shaft of the engine.
The generator represents the three-phase synchronous electrical machine with electromagnetic excitement. For transformation of alternating current in constant the rectifier on diodes is built in the generator. Tension is regulated by the built-in microelectronic regulator of tension.
During the operation of the generator the electric current proceeding on an excitement winding creates magnetic field around rotor poles. At rotation of a rotor under stator coils alternately there pass rotor poles, the magnetic flux changes in size and the direction and creates the electromotive force in a stator winding.
With a high frequency of rotation of a rotor of the generator when tension of the generator becomes more than 13,6-14,6 B, the regulator of tension is locked and current does not pass through a winding of excitement. Tension of the generator falls, the regulator opens and again passes current through an excitement winding. The frequency of rotation of a rotor of the generator is higher, the time of the locked condition of the regulator is more, therefore, the stronger tension at the generator exit decreases. Process of locking and unlocking of the regulator happens with high frequency therefore fluctuations of tension at the exit of the generator are not noticeable, and the constants supported at the level of 13,6–14,6 Century can almost consider it.
When checking the generator, and also at operation of the car it is necessary to follow a number of simple rules not to put the generator out of action:
– do not allow operation of the generator with the disconnected rechargeable battery. During the operation of the generator with the disconnected battery in onboard network of the car tension at shutdown of any consumers of the electric power increases that leads to failure of the electronic equipment of the car, including regulator of tension and the vypryamitelny block of the generator;
– do not check operability of the generator for "spark" even short-term connection of a "plus" conclusion of the generator with "weight". At the same time via the vypryamitelny block current of big force proceeds and diodes are damaged. It is possible to check generator tension only the voltmeter;
– the "minus" plug of the rechargeable battery always has to connect to "mass" of the car, and "plus" to a generator conclusion. The wrong (return) connection of the battery vyzyvt sharp increase in the current passing through generator diodes, and they will fail;
– do not check diodes more than 12 V or the megohm meter as it has tension, too high for diodes. In this case when checking diodes will be punched (there will be a short circuit). When checking isolation of an electrical wiring the megohm meter disconnect all wires from the generator;
– it is necessary to disconnect all wires from the generator and the rechargeable battery at electric welding of knots and details of a body;
– check chains and knots of electric equipment and eliminate malfunctions at the idle engine and the disconnected rechargeable battery.
Before removal of the generator disconnect the rechargeable battery, previously having found out whether you have a code of turning on of the radio receiver.
Switch off ignition and disconnect a wire of "weight" from the rechargeable battery.
After installation of the generator connect a wire of "weight" to the rechargeable battery.
Turn on the radio receiver and enter into it a code.
Lift glasses power windows up to an emphasis. Then press all switches of a window regulator once again, at least for 1 second, in the provision of closing for activation of the control unit of window regulators.
Determine time on hours.
Six-cylinder petrol engines
Removal
Release clamps and remove the lower mudguard of a motor compartment.
Disconnect and remove a generator air duct.
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Fig. 18-14. An arrangement of a clamp (1) of a casing and the direction of turning for removal of the electric fan of a radiator
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For removal of the electric fan of a radiator disconnect the electric socket from the fan, take a casing clamp, turn a casing in the direction of an arrow (fig. 18-14) and remove the fan.
Unscrew screws and remove a casing of a poliklinovy belt.
Chalk, marker or paint note the direction of rotation of a poliklinovy belt. If at installation poliklinovy the belt rotates in other party, it will lead to its destruction.
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Fig. 18-15. Weakening of a tension of a poliklinovy belt: 1 and 2 – installation sites of pins for fixing of the mechanism of a tension. The arrow showed the direction of rotation of a six-sided key for reduction of a tension of a poliklinovy belt.
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Face six-sided key on 10 mm weaken a tension of a poliklinovy belt for what turn the tension mechanism clockwise before combination of openings (fig. 18-15).
Fix the tension mechanism in this situation, having inserted a steel core with a diameter of 5 mm into an opening.
Take off poliklinovy a belt from a generator pulley.
Merge cooling liquid from the cooling system.
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Fig. 18-17. Elements of fastening of the generator on cars with six-cylinder petrol engines: 1 – nut, 45 N · m; 2 – bolt; 3 – bolt, 22 N · m; 4 – generator
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Unscrew a nut of the top fastening of the generator, holding a bolt from a provorachivaniye (fig. 18-17). Take the top bolt of fastening of the generator.
Unscrew a bolt of the lower fastening of the generator 3 and remove the generator.
Installation
Installation is carried out to the sequences, the return to removal, taking into account the following.
Check correctness of an arrangement of a poliklinovy belt on pulleys.
Tighten the lower bolt of fastening of the generator the moment of 22 N · m.
Tighten a nut of fastening of the generator the moment of 45 N · m.
Tighten nuts of fastening of wires to a conclusion "30/B+" the moment of 16 N · m, to a conclusion of "D+" – the moment of 4 N · m.
Six-cylinder diesel engines
Removal
Unscrew screws and remove the lower mudguard of a motor compartment.
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Fig. 18-18. Tension of a poliklinovy compressor belt of the conditioner: 1 – bolt of fastening of a roller of a tension of a poliklinovy belt; 2 – poliklinovy conditioner compressor belt; 3 – dynamometer key
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Weaken a bolt of fastening of a roller of a tension of a poliklinovy compressor belt of the conditioner and take off a belt from pulleys (fig. 18-18).
Face key turn counterclockwise the mechanism of a tension of the main poliklinovy belt therefore the tension will be weakened, fix the tension mechanism in this situation a pin (fig. 18-19) with a diameter of 4 mm and take off a belt from the generator.
Before removal, chalk, a marker or paint note the direction of rotation of a poliklinovy belt. If at installation the belt which was earlier used poliklinovy rotates in other party, it will lead to its destruction. Make sure that poliklinovy the belt is correctly located on pulleys.
Unscrew nuts and disconnect wires from conclusions "30/B +" and "D +" the generator (see fig. 18-12).
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Fig. 18-20. An arrangement of bolts (1 and 2) of fastening of the generator on cars with six-cylinder diesel engines
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Installation
Installation is carried out to the sequences, the return to removal, taking into account the following.
Check correctness of an arrangement of a poliklinovy belt on pulleys.
Tighten the right bolt 1 (see fig. 18-20) fastenings of the generator the moment of 22 N · m and the left bolt the 2nd moment of 45 N · m.
Eight-cylinder petrol engines (3,7 and 4,2 l)
Removal
Unscrew screws and remove the lower mudguard of a motor compartment.
Disconnect and remove a generator air duct.
Unscrew nuts and disconnect wires from conclusions "30/B +" and "D +" the generator (see fig. 18-12).
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Fig. 18-21. Installation of device 3204 for weakening of a tension of a poliklinovy belt on eight-cylinder petrol engines
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Weaken a tension of a poliklinovy belt, using devices 3204, and take off a belt from the generator (fig. 18-21).
Chalk, marker or paint note the direction of rotation of a poliklinovy belt. If at installation poliklinovy the belt rotates in other party, it will lead to its destruction.
Unscrew a nut of the top fastening of the generator, holding a bolt from a provorachivaniye (see fig. 18-17). Take the top bolt of fastening of the generator.
Unscrew a bolt 3 (see fig. 18-17) the lower fastening of the generator and remove the generator.
Installation
Installation is carried out to the sequences, the return to removal, taking into account the following.
Check correctness of an arrangement of a poliklinovy belt on pulleys.
Tighten the lower bolt of fastening of the generator the moment of 22 N · m.
Tighten a nut of fastening of the generator the moment of 45 N · m.
Tighten nuts of fastening of wires to a conclusion "30/B+" the moment of 16 N · m, and to a conclusion of "D+" – the moment of 4 N · m.