8.3. Generator

On the car generators of two types can be installed:

Fig. 7.13. G250P2 generator: 1 – brush holder; 2 – bearing cover; 3 – back bearing;
4 – block of rectifiers; 5 – back cover; 6 – back magnet; 7 – stator; 8 – forward cover; 9 – fan; 10 – forward bearing; 11 – pulley; 12 – nut; 13 – segment spline; 14 – expansion plug


Fig. 7.14. Electric scheme of the G250P2 generator: 1 – brush; 2 – contact ring; 3 – excitement winding; 4 – rectifier; 5 – heat sink; 6 – stator winding


– G250P2 (fig. 7.13) – alternating current with the VBG-1 built-in vypryamitelny block (or PBV-4-45), working together with tension regulator. The electric circuit of the generator is shown in fig. 7.14.

Fig. 7.15. Electric circuit of generators 665.3701-01, 161.3771: 1 – brush; 2 – contact ring; 3 – excitement winding; 4 – stator winding; 5 – rectifier; 6 – pomekhopodavitelny condenser. (* For the generator 161.3771)


– 665.3701–01 or 161.3771 – alternating current with the built-in integrated regulators of tension. The electric circuit of generators is shown in fig. 7.15.
The generator fastens on an arm to the engine block on the right side. The generator is given to rotation by means of a wedge-shaped belt from a pulley of a bent shaft.

Specifications of the G250P2 generator
The direction of rotation (from the drive)..... right
Tension (nominal), In..... 14
Rated current, And..... 28
Maximum current, And..... 40±5
Frequency of rotation of a shaft of the generator with which tension on plugs 12,5 B at a temperature of air and the generator of 20 °C, mines-1 is reached:
   at the current equal to zero..... 900
   at current of loading 28 A..... 2100
Number of phases of the stator (are connected by a star)..... 3
Number of coils in a phase..... 6
Number of coils of the stator..... 18
Number of rounds in the stator coil..... 13
Stator winding..... wire of PEV-2, Zh 1,35-1,46 of mm
Excitement winding coil..... wire of PEV, Zh 0,74-0,83 of mm
Number of rounds in the coil..... 490±10
Excitement winding resistance at 20 °C, Ohm..... 3,7±0,2
Excitement winding current, And, no more..... 3,05±0,2
Type of brushes..... M1
Effort of pressing of springs to brushes, гс..... 180–260
Ball bearings:
   in a forward cover..... 180603-KC9'
   in a back cover..... 180502-KS9Sh
Number of diodes of the vypryamitelny block..... 6
Admissible current on each diode, And..... 10
Admissible power failure at current 10 A, B, no more..... 1

Specifications of generators 665.3701-01, 161.3771
The direction of rotation (from the drive)..... right
Tension (nominal), In..... 14
Maximum current, And, not less..... 55 (57)
Adjustable tension at the ambient temperature of 25±10 °C, frequency of rotation of a rotor of 3500 min.-1 and current of loading 20A during the work with the switched-on battery, In:
   for execution of "U-HL"..... 13,9–14,6
   for execution of T..... 13,4–14,1
Adjustable tension at ambient temperature from –25 °C to +70 °C at change of current from 5A
to 40A and frequencies of rotation of a rotor from 3000 min.-1 to 8000 min.-1, In:
   for execution of "U-HL"..... 13,6–14,8
   for execution of T..... 12,9–14,8

Begin survey of the generator with brushes, the brush holder and contact rings. Make sure that brushes are whole, do not jam in brush holders and reliably adjoin to contact rings; check a tension of springs of brushes. The brushes which are worn out up to the height of 8 mm (for generator 665.3701-01 brushes – 5 mm), replace.

Fig. 7.16. Check of effort of pressing of brushes


Measure by a dynamometer effort of pressing of brushes (fig. 7.16) to contact rings. For measurement of effort remove the brush holder, remove one brush, install a cover on the brush holder, holding it a hand. Then the end of a brush acting from the brush holder press on a cup of arrow scales. When the brush acts from the brush holder on 2 mm, measure the indication of scales. The effort of pressing of springs to brushes has to be 180–260 гс.
Blow the generator air. Wipe the brush holder, brushes and slightly polluted contact rings with the pure rag which is slightly moistened in gasoline. Smooth out strongly polluted contact rings with a small podgoraniye and small roughnesses (having removed the brush holder) glass paper granularity 80 or 100, turning a rotor by hand. Do not apply for this purpose a grinding skin. Pierce the contact rings of the generator which are worn out, burned slightly or having the raised beating on the lathe and carefully smooth out.
Periodically remove the generator from the car for dismantling and its cleaning of dirt and dust. Carefully examine all details. Check effort of pressing of brushes. Brushes should not jam in brush holders. Replace worn-out bearings. Check the assembled generator how it is specified in the head "Control check of the generator".

Preventions
1. "Minus" of the rechargeable battery always has to connect to "weight", and "plus" - is connected to a clip "plus" the generator. Wrong return turning on of the battery will immediately cause the raised current via diodes of the generator and they will fail.
2. Operation of the generator with disconnected from a clip "plus" wires of consumers is not allowed (especially with the disconnected rechargeable battery). It causes dangerous increase in tension that involves damage of diodes and the regulator of tension.
3. It is not necessary to check operability of the generator "on a spark" even short-term connection of a clip "plus" the generator with "weight". At the same time through diodes there passes considerable current and they are damaged.
It is possible to check the generator only by means of the ampermeter and the voltmeter.

Regulator of tension 2702.3702

Fig. 7.17. Tension regulator: 1 – handle of the switch of ranges of control; 2 – conclusion "Ш"; 3 – conclusion "+"


The G250P2 generator works together with the contactless transistor regulator of tension of 2702.3702 (fig. 7.17) which has three ranges of control of adjustable tension. Change of ranges of adjustable tension is carried out by the switch located on the top part of the case of the regulator. Situation a rychazhka of the switch corresponds to tension ranges: "max." (maximum), "min." (minimum), "ср" (average). From the plant the regulator is issued with an average range of control.
 Technical characteristic of the regulator of tension
Tension supported by the regulator at ambient temperature plus 20 °C In:
in position of the mines switch..... 13,6±0,35
in position of the sr switch..... 14,2±0,35
in position of the max. switch..... 14,7±0,35
Frequency of rotation of a rotor of the generator with which adjustable tension, min.-1 is checked..... 3500
Loading current at which adjustable tension is checked, And..... 14

Maintenance of the regulator of tension consists in periodic check of its parameters. Check can be made directly on the car or at the stand.
For check it is necessary to have the voltmeter of a direct current with a scale to 20–30 V and at the cost of division of 0,1 - 0,2 Century. Turn on this voltmeter between "weight" and a conclusion "+" the generator. Record adjustable tension according to the indication of the voltmeter for three provisions of the switch.
If indications of the voltmeter go beyond specifications, then replace tension regulator.
The condition of an electrical wiring between the generator, the regulator of tension and the rechargeable battery, and also reliability of their connection with "weight" is important for normal operation of the generator together with the regulator of tension.
The size of adjustable tension is influenced by a condition of contacts of the switch of ignition. If contacts burned slightly, then adjustable tension will rise. Power failure on conclusions of the switch of ignition has to be no more than 0,15 In at current 12 A. Before looking for malfunctions in operation of the generator or regulator of tension, carefully check a condition of an electrical wiring, correctness of the scheme of connection of wires and reliability of the switch (lock) of ignition and starter. The malfunctions found when checking (wire breakage, isolation violation, short circuit, pollution of tips etc.) have to be eliminated. With a big resistance replace the switch (lock) of ignition and starter.
At failure of the regulator of tension in way follows:
– to disconnect a wire from conclusion "Ш" of the regulator of tension, without allowing short circuit it on "weight";
– through each 150–200 km of a run to make recharge of the rechargeable battery for what to connect to the disconnected wire for 30 - 40 min. an electric lamp of 5-21 W (a lamp of a marker light, a braking signal lamp).
On the voltmeter at the working engine you watch tension in the car power supply network (the arrow of the device should not pass into a red zone at the end of a scale).