Generator G221A: 1 - output "67"; 2 - brush holder; 3 - central terminal of the stator winding; 4 - pin "30"; 5 - generator rear cover; 6 - Generator front cover; 7 - generator mounting stud to tension bar; 8 - pulley; 9 - stator
Technical characteristics of the G-221A generator:
|
Nominal voltage, V |
12 |
|
Maximum output current at 14 V and rotor speed of 5000 rpm, A |
42 |
|
Power, W |
600 |
|
Weight, kg |
4,28 |
The main parts of the generator are the rotor, stator and covers, cast from aluminum alloy.
Generator G221A details: 1 - pulley; 2 - segment key; 3 - Generator front cover; 4 - outer bearing mounting washer; 5 - Front rotor bearing; 6 - rotor; 7 - tie bolt; 8 - stator; 9 - rear rotor bearing; 10 - buffer bushing; 11 - back cover; 12 - insulating bushings; 13 - bolt; 14 - brush holder; 15 - rectifier block; 16 - contact bolt; 17 - bolt; 18 - bolt; 19 - inner bearing mounting washer; 20 - fan impeller
Rotor consists of a shaft, on the corrugated surface of which a steel sleeve and steel beak-shaped poles are pressed, which together with the shaft and the rotor sleeve form the core of the electromagnet. The rotor winding is placed on the sleeve between the poles in a plastic frame (excitation winding). The winding terminals are soldered to contact rings mounted on a plastic sleeve located on the shaft. At the front end of the rotor shaft, a pulley and impeller of the cooling fan are secured with a nut using a segment key. The rotor shaft rotates in two ball bearings installed in the generator covers. The rear bearing is pressed onto the rotor shaft, and the front bearing is held in the cover by special washers secured with four bolts and nuts.
Stator is assembled from electrical steel plates. A three-phase winding is placed in the grooves on the inner surface of the stator. Each winding consists of six series-connected coils. Some terminals of the windings are connected to pairs of diodes of the rectifier unit, and others - to the central terminal of the generator, which is connected by a wire to terminal "85" of the battery charge indicator relay.
To convert alternating current to direct current, the generator has a built-in rectifier block on six silicon diodes, installed in the back cover and secured to it with three bolts. The diode housings are pressed into two aluminum holders for positive and negative diodes, isolated from each other, assembled into a single block. Three diodes have a "plus" on the housing (positive diodes), the other three are "minus" (negative diodes). The positive diode holder is equipped with a contact bolt of the generator terminal "30". The negative diode holder is connected to the generator rear cover - "ground".
The brush holder is secured with a screw to the rear cover of the generator. One of its brushes is connected to the "ground", and the other, through the "67" terminal of the generator, to the voltage regulator.
Voltage regulator is designed to maintain the nominal voltage in the vehicle's electrical network regardless of the shaft rotation speed. The regulator is connected to the ignition switch via pin "15".
Warning! Do not operate the generator with the battery disconnected. This will cause short-term voltages to appear on the "30" terminal of the generator, which may damage the generator voltage regulator and electronic devices in the vehicle's on-board network.
[The text is published on the portal: VAZbook]