Open large image in new tab »
1. Generator cover on the drive side. 2. Stator. 3. Stator winding wedge (a tube). 4. Stator winding. 5. Rectifier diode (positive). 6. Sleeve. 7. Buffer sleeve. 8. Clamping sleeve. 9. Rectifier diode (negative). 10. Screw for fastening the holder of diodes and, phase leads of the stator winding. 11. Cover of the generator from the side of slip rings. 12. Insulating sleeve. 13. Coupling bolt. 14. Rotor shaft. 15. Ball bearing of the rotor shaft. 16. Positive brush. 17. Negative brush. 18. Terminal bolt (conclusion «30»). 19. Plug of the central output of the star of the stator winding. 20. Negative brush connection plate. 21. Brush holder. 22. Positive brush plug (conclusion «67»). 23. Internal washer of fastening of the bearing. 24. Bearing distance ring. 25. Ball bearing of the rotor shaft on the drive side. 26. Generator fan pulley. 27. Outer bearing washer. 28. Beak-shaped pole piece of the rotor. 29. Rotor sleeve. 30. Rotor winding. 31. Rotor winding frame. 32. Insulating washer. 33. Conclusion of the contact ring of the negative brush. 34. Insulating sleeve slip rings. 35. Hub of the insulating sleeve of slip rings. 36. Negative brush contact ring. 37. Contact ring positive brush. 38. Insulating plate for positive diode leads. 39. Wire of the phase output of the stator winding. 40. Rectifier positive diode holder. 41. Wire of the central output of the star of the stator winding. 42. Insulating block of the plug. 43. Reference prisms. 44. Positive plate. 45. Separator. 46. Negative plate. 47. Bridge baretque. 48. Barette pin. 49. Battery case. 50. The roof of the battery section. 51. Filler plug. 52. Sleeve. 53. Positive output terminal. 54. Connecting bridge. 55. Negative output terminal. 56. Body partitions. 57. Plate legs. a - holes for the leads of the rotor winding; b - filling hole.
Accumulator battery
Technical specifications:
- Rated voltage, V - 12
- Rated capacity at a 20-hour discharge mode and an electrolyte temperature of 25°C at the beginning of the discharge, Ah - 55
- Weight (with electrolyte), kg - 21
On cars «Zhiguli» a 6ST-55 lead acid battery is installed, which serves to power the consumers of the car with electric current when the engine is not running, as well as to start the engine.
The battery case 49 is made of ebonite and is divided by impenetrable partitions 56 into six sections, in which six batteries connected in series with a voltage of up to 2 V are placed. Each battery consists of a block of plates. The block consists of half-blocks of positive and negative plates. The plates are gratings cast from an alloy of lead and antimony, the cells of which are filled with a porous active mass. Plates of the same polarity are welded with ears to a barette, consisting of a pin 48 and a bridge 47. The barette serves to fasten the plates and output current.
The plates in the block are isolated from each other by thin and porous separators 45 made of polyvinyl chloride. The small thickness and high porosity of the separators facilitate the penetration of the electrolyte to the plates, reduce the internal resistance of the battery, and make it possible to obtain a significant discharge current at low temperatures. For some batteries, the block of plates with separators is closed on top with a protective shield made of plastic mesh.
The top sections of the case are closed with ebonite covers 50 with holes along the edges for the passage of leads and with a central threaded hole for filling the electrolyte and checking its level. In the extreme holes there are lead bushings 52, to which the pins of the semi-blocks and bridges 54 are welded, connecting individual batteries.
The compartment covers and connecting bridges are filled with a special acid-resistant mastic, which seals the battery sections well and protects the connecting bridges from damage, corrosion and accidental short circuits.
An electrolyte is poured into the batteries, which is a solution of sulfuric acid in distilled water. The density of the electrolyte of a fully charged battery at +25°C should be 1.28 g/cm3 for temperate climates and 1.22 g/cm3 for tropical.
The normal electrolyte level in the batteries should be 5-10 mm above the safety shield or the top edge of the separators. If the center hole of the battery has a deep neck (tube), then the electrolyte level should reach its lower edge. At the same time, the meniscus is clearly visible in the lower opening of the neck.
Generator
Technical specifications:
- Direction of rotation - Right
- Rated voltage, V - 12
- Maximum recoil current (at 14 V and 5000 rpm), A - 42
- Gear ratio engine-generator - 1:2.04
- Generator weight without pulley, kg - 4.2
On cars «Zhiguli» an alternating current generator of the G-221 type is installed, which serves to supply the consumers of the car with electric current and to charge the battery.
The generator is a three-phase synchronous electric machine with electromagnetic excitation. To convert alternating current to direct current, a six-silicon diode rectifier is built into the generator.
The main parts of the generator: rotor, stator 2 and covers 1 and 11, cast from aluminum alloy.
The rotor consists of a shaft 14, on the corrugated surface of which a steel sleeve 29 and steel beak-shaped poles 28 are pressed, forming together with the shaft and sleeve the core of the electromagnet. On the sleeve 29 between the poles in the plastic frame 31 placed the excitation winding 30 of the rotor. The ends of the winding are brought out through holes a in the pole and soldered to the terminals of the slip rings.
The rotor rotates in two sealed ball bearings. Grease is incorporated into the bearings during manufacture and does not require replenishment during operation. The inner race of the front bearing 25 is loosely fitted on the rotor shaft and, together with the spacer ring 24, is clamped between the pulley hub and the shaft shoulder with the pulley fastening nut. The outer race of the bearing 25 is pressed into the cover and fixed between two washers 23 and 27 tightened with four screws. The inner race of the rear bearing 15 is pressed onto the rotor shaft; the outer clip is pressed with a rubber ring.
A pulley 26 with a fan, made of sheet steel and connected by electric welding, is installed on the rotor shaft on a segment key.
The fan serves to cool the rectifier and the internal parts of the generator.
The stator is assembled from plates of electrical steel 1 mm thick. The plates are connected by electric welding. On the inside of the stator there are 36 semi-closed slots, insulated with varnish or electrical insulating cardboard. A three-phase winding is laid in the grooves, secured from falling out with wooden wedges or plastic tubes. Each phase winding consists of six coils. Phase windings are connected in a star with an output (plug 19) zero point.
On the back cover 11 of the generator, a brush holder 21 with brushes 16 and 17 is fixed with a screw. Through the brushes, pressed by springs to the contact rings of the rotor, current is supplied to the excitation winding. One of the brushes through plate 20 is connected to the ground of the generator, and the other is connected to the plug «67».
Rectifier parts are also fixed on the rear cover of the generator. The rectifier is assembled according to a three-phase bridge circuit of six silicon diodes of the VA-20 type - semiconductor devices that pass electric current in only one direction.
In order to simplify the details of fastening the rectifier, three diodes are on the case «plus» rectified current («positive» diodes), and three diodes - «minus» rectified current («negative» diodes). Negative diodes, which have a common lead to ground in the rectifier circuit, are pressed into the cover 11 of the generator. They are black marked. positive diodes (with red marking) in the rectifier circuit have a common terminal connected to the clamp «30» generator, and are pressed into an aluminum holder 40. The diodes are pressed in order to ensure efficient heat removal from the body of the diodes to the holder 40 and cover 11, which are purged with air for cooling. The holder is attached to the cover 11 with three bolts 10, insulated together with the holder from the cover with plastic bushings 12. The nuts of these bolts simultaneously clamp the leads of the diodes and the stator winding. Clamp attached to the holder «30» generator (bolt 18), which is the output «plus» rectifier. Conclusion «minus» is the mass of the generator.
The generator works as follows. When the ignition switch is in the IGNITION position, an electric current flows through the field winding, creating a magnetic flux around the rotor poles. When the rotor rotates, then the south and then the north pole of the rotor passes under each stator tooth, and the working magnetic flux passing through the stator teeth changes in magnitude and direction. This variable magnetic flux creates an electromotive force in the stator winding. The beak-shaped shape of the rotor poles is chosen in such a way that it makes it possible to obtain the shape of the electromotive force curve close to sinusoidal.
Voltage regulator
Open large image in new tab »
1. Protective plate. 2. Contact rack mass. 3. Nut of fastening of racks. 4. Cover. 5. Anchor. 6. Bimetallic plate. 7. Yarmo. 8. Cover gasket. 9. Foundation. 10. Upper insulating gasket 11. Lower spring bracket. 12. Anchor spring. 13. Upper spring bracket. 14. Rack of the top contact. 15. Rack of the lower contact. 16. Regulator winding. 17. Throttle. 18. Bottom insulation pad. 19. Thermal compensation resistor. 20. Nut for fastening the yoke and core of the coil. 21. Additional resistor. 22. Yarmo. 23. Spring plate. 24. Lid. 25. Anchor. 26. Contact stand. 27. Relay mounting bracket. 28. Foundation. 29. Relay winding. 30. Plug. 31. Voltage regulator. 32. Instrument cluster. 33. Battery charge control lamp. 34. The relay of a control lamp of a charge of the accumulator battery. 35. Ignition switch. 36. Fuse box. 37. Battery. 38. Generator.
Technical specifications:
- Rated voltage, V - 12
- Adjustable voltage at 50°С, V:
- at the second stage — 14.2±0.3
- at the first stage lower than at the second - by 0.7
- Temperature compensation resistor - 19 ohm, 6 W
- Additional resistor - 5.5 ohm, 25 W
On cars «Zhiguli» a two-stage vibration regulator type PP-380 is used. The purpose of the regulator is to maintain the voltage generated by the generator at a constant level (13-14 V), to ensure the normal operation of the vehicle's electrical equipment and the necessary battery charge mode. The regulator is plugged down in the engine compartment on top of the left wheel mudguard.
The voltage regulator consists of a U-shaped yoke 7, a cylindrical core, on which a winding 16 is located in a plastic coil, an armature 5 with two contacts (top and bottom) and two racks 14 and 15 with fixed contacts. The posts are fixed at the other end of the yoke with a nut 3 with a screw, the head of which is welded to the yoke. Racks 14 and 15 are isolated from each other and from the yoke by plastic gaskets. Slots in the uprights allow you to move them up and down when adjusting the regulator. Two armature contacts (upper and lower) with two contacts on the racks form two pairs of contacts: the upper K, and the lower K2. The armature is pressed against the upper contact by spring 12, i.e. a pair of contacts K1 is normally closed. Opening and closing contacts K1 the first stage of regulation is provided, and by closing and opening contacts K2 is the second stage of regulation.
The yoke with the core is isolated from the steel stamped base 9 with a plastic gasket 10. At the lower end of the core there is a thread with which the nuts 20 and the core with the anchor are attached to the base 9. On the bottom side of the base on the plastic gasket 18, a thermal compensating 19 and additional 21 resistors are installed. Nichrome resistor wire is wound on a fiberglass cord impregnated with silicone varnish.
A choke 17 is also installed on the basis of the regulator, designed to reduce sparking between the upper pair of contacts during the operation of the regulator. It is a steel core with a winding of copper wire wound on a plastic frame.
From above, the regulator is tightly closed with a steel cover 4 with a gasket 8 made of polyurethane. The ingress of moisture and various substances under the cover leads to contamination, burning of contacts and disruption of the normal operation of the regulator. For this reason, all materials used in the regulator have been tested for non-outgassing.
Relay of a control lamp of a charge of the storage battery
Technical specifications:
- Rated voltage, V - 12
- Contact closing voltage*, V — 5.3±0.4
- Contact opening voltage*, V — 0.2—1.5
- Winding resistance at 20 C, Ohm - 29
* At a temperature of 25±5°С.
The RS-702 relay is designed to turn on the control lamp on the instrument panel when the generator voltage is not enough to charge the battery. The relay is installed in the engine compartment on top of the right wheel mudguard.
The relay consists of a yoke 22, a steel core with a winding 29, an armature 25 and a stand 26 with a fixed contact. The yoke with the core and the post are mounted on a getinax base 28. Anchor 25 is attached to the yoke shelf using a spring steel plate 23. To improve the electrical connection of the yoke with the anchor, there is a copper plate under the spring plate. The relay contacts are made of an alloy of silver and copper. The armature contact is pressed against the rack contact by a spring plate, so the relay contacts are normally closed.
Generator system operation
In the operation of the generator system, three modes can be distinguished: operation at low, medium and high revolutions of the generator rotor.
I mode. This is the start mode. engine when the engine is not running. In this case, the generator either does not develop voltage yet, or it is less than the battery voltage and all consumers are powered by the battery.
When the ignition is turned on, a current flows in the excitation winding circuit of the generator, closing along the path: «plus» battery - clamp «30» generator - contacts «30/1» and «15» ignition switch - fuse «L» - plug «15», upper pair of regulator contacts, armature, yoke plugs «67» regulator and generator - excitation winding of the generator - ground - «minus» battery.
The current flowing through the excitation winding creates a magnetic flux, which, when the generator rotor rotates, crosses the turns of the generator stator winding and creates an electromotive force in them.
At the same time, the current flows through the winding 16 of the voltage regulator, closing along the path: from «pluses» battery to plug «15» voltage regulator, as described above, and then thermal compensation resistor 19 - winding 16 of the regulator - ground - «minus» battery. This current creates a magnetic attraction of the regulator armature to the core, but not yet strong enough to attract the armature to the core and open the top pair of contacts (TO1).
When the ignition is switched on, the control lamp 33 of the battery charge lights up. The current feeding it closes along the path: «plus» battery - contacts «30/1» and «15» ignition switch - fuse «I» - plug «87», normally closed contacts, armature, yoke, plug «30/51» relay 34 - control lamp 33 - ground - «minus» battery. Since the engine is not yet running, the phase voltage of the generator is zero. The current does not flow through the winding 29 of the relay 34, the armature is not attracted to the core, the relay contacts remain closed and the lamp 33 is on, signaling that all consumers are powered by the battery.
II mode. After starting the engine, the rectified voltage of the generator exceeds the voltage of the battery. The excitation winding of the generator and the winding 16 of the voltage regulator are powered by the generator. In this case, the current does not flow from the terminal «plus» battery, but from the clamp «30» generator and closes through the ground to the generator rectifier. The battery is being charged.
Under the action of the rectified phase voltage, a current flows through the winding 29 of the relay 34, closing on the way: clamp «30» generator - contacts «30/1» and «15» ignition switch - fuse «I» - plugs «87», «86», winding 29, plug «85» relay 34 - plug output of the zero point of the generator stator winding and generator rectifier. When the rectified phase voltage reaches 5.3-5.7 V, the armature will be attracted to the relay core, the relay contacts will open and lamp 33 will go out, indicating that the rectified generator voltage has become greater than the battery voltage and that the generator has begun to charge the battery and power consumers.
With an increase in the frequency of rotation of the generator rotor, when the voltage reaches 13.2-14.3 V, the magnetic force overcomes the resistance of the armature spring and attracts it to the core. At the same time, the contacts1 open, an additional resistor 21 is included in the circuit of the excitation winding of the generator and the current through the excitation winding is closed along the path: clamp «30» generator - contacts «30/1» and «15» ignition switch - fuse «L» - plug «15» regulator, choke 17, additional resistor 21, plug «67» regulator - excitation winding of the generator.
The inclusion of an additional resistor in the excitation winding circuit of the generator reduces the current strength in it. This, in turn, leads to a decrease in the electromotive force in the generator stator winding and the generator voltage drops. Accordingly, the current through the regulator winding and the magnetic attraction of the armature to the core decrease. Under the action of the spring, the armature returns to its original position, closing the contacts K1. The generator voltage rises and the described process is repeated again.
Closing and opening contacts K1 occurs at a frequency of 25-250 times per second and the generator voltage at the output of the rectifier with the same frequency either rises or falls. Due to the high frequency of opening and closing contacts K1, voltage fluctuations are imperceptible and practically can be considered constant, maintained at an average level of 13-14 V.
With a further increase in the frequency of rotation of the generator rotor, the time of the open state of the contacts K1 increases, and the closed state time decreases. Due to this, the average voltage at the output of the generator rectifier increases slightly.
III mode. At high speeds of the generator rotor, the first stage of regulation (on contacts K1) no longer ensures that the voltage is maintained at 14 V, since the additional resistor has a relatively small value (5.5 ohm). The generator voltage rises to 13.9-14.5 V and the armature is attracted to the core until the contacts close K2. In this case, the excitation winding of the generator is closed to ground as follows: mass, excitation winding - plug «67» generator - plug «67», yoke, armature, closed contacts K2, mass of the regulator. Since both ends of the excitation winding are shorted to ground, the current in it drops sharply to zero. This leads to a sharp decrease in the generator voltage, the magnitude of the current through the winding 16 decreases sharply and the magnetic attraction of the armature to the core decreases. The spring pulls the armature away from the core, contacts K2 open and the described process is repeated again with a frequency of 80-100 times per second.