automotive generator is converted into electrical energy to other forms of mechanical equipment, it originated in the second industrial revolution, made of a German engineer Siemens in 1866, which consists turbine, steam turbine, a diesel engine or other mechanical power drive, the energy flow, gas flow, or nuclear fission fuel combustion into mechanical energy produced by the generator to pass, and then converted to electricity by the generator. Generator power is increased with increase in the car and electrical equipment increased. Now the generator is air-cooled vehicle generator, by the fan into the casing after the hair is cooled pulley. In conventional air-cooled generators limiting configuration, the power increase will inevitably lead to an increase in volume of the generator. Automotive power generator is the main part of the car, which function at the time of normal operation of the engine (idling above), and is responsible for charging the battery power supply means during operation of the vehicle. Automotive generators can be divided into direct current generators and alternators, because the alternator is superior in many respects DC generator, DC generator has been eliminated, now almost all cars currently use the alternator.
1 generator Category
1. Press junction overall structure Category
(1) Normal alternator (fitted required when using a generator voltage regulator)
(2) integral AC generation machine (a generator and a regulator formed integrally generator)
(3) a permanent magnet alternator (magnetic poles made of a permanent magnet generator)
(4) with pump alternator (AC generator Ann pump with vacuum pump is not a vacuum booster pump, the pump is a vacuum booster vehicle brake system)
(5) of the brushless alternator (no brushes generator)
2. press the end of the field winding type classifier Ground Ground alternator field winding type) of
(1 (negative electrode) directly take iron (and associated housing)
One end (2) Ground alternator field winding type (negative) access controller, and then to ground through the regulator.
3. Classification by rectifier structure .
(1) six alternator.
(2) eleven alternator.
(3) eight alternator.
(4) nine alternator.
2. The operating characteristics of the automotive generator
rotational speed
large automotive engine from idle to maximum speed range, the rotational speed of the generator which drive the respective ranges areInternal change. Characteristics Alternator, it should be based on the speed to analyze the correspondence between the various relevant parameters as a benchmark. The operating characteristics of the alternator is the relationship between the DC voltage rectified generator output current and speed. It includes an output characteristic, load characteristic, and external characteristics.
1. The load characteristics
during idle running generator. The relationship between the terminal voltage and the generator speed, the generator load characteristics may determine whether the cruise charging performance is good or bad, but also can be seen that the generator output voltage is increased as the rotational speed of the generator and increased.
2. Output characteristics
When the generator output voltage constant, the rotational speed of the generator output current with changes in the law. Because of this self-protection effect, the alternator is generally not necessary to provide a flow restrictor.
3. External Characteristics
When the generator speed constant, the relationship between the generator terminal voltage and output current, the characteristic curve can be seen from the outside, when the speed changes, the generator end greater voltage change at constant speed, due to changes in the output current has a great influence on the terminal voltage, therefore, to make the output current stability, it must be equipped with a voltage regulator. At high speed, the sudden loss of the load when the generator terminal voltage rises sharply, then the electronic components and electronic equipment would be in danger of breakdown. .
Note 3 generator
is now widely used at present alternator on the car, at the same time when using the following points should be noted:
① often clean power generation machine and appearance of foulingDust, clean and well-ventilated.
② frequently check the tightness of a generator associated with each fastener, the fastening promptly any screws.
③ to the right drive belt tension. Too loose, slippery caused by insufficient power generation; tight, easy to damage the belt and generator bearings.
④ When installing the battery, do not install the wrong usually installed to the positive line, grounding line is not installed, or easily burn diode. When
⑤ Integrated circuit regulator is not operated immediately turn the engine ignition switch.
⑥ not fire allows the doctor whether the test generation method. When
⑦ generator power failure does not have to be immediately removed, otherwise it will cause more serious problems.
4. The structure and characteristics of the generator
1. Alternator part
(a) a stator
AC generation stator function is to generate an alternating current, the stator is a stator core and a stator winding composed of two parts, however, the stator core is formed by laminating silicon steel plates of the inner ring is slotted, wire winding on the stator core fitted in the groove.
(ii) functions of the rotor
rotor of the alternator is a rotating magnetic field. The rotor claw poles of the yoke, the field winding, collector ring, composed of the rotor shaft.
magnetic circuit
for the AC generator: a yoke rarr; N-pole rarr; rarr air gap between the rotor and the stator; a stator rarr; stator and the rotorThe air gap between rarr; S poles rarr; yoke.
(c) a rectifier
Function
is a rectifier of the alternator stator winding of three-phase alternating current into direct current, a rectifier 6 alternator is composed of three rectifier diodes 6 phase full-wave bridge rectifier circuit, the rectifier 6 respectively press-fitted (or welding) on both plates.
(iv)
Usually two-part cover (front cover and the rear cover), the fixed end cap acts as a rotor, a stator, a rectifier and a brush assembly. General aluminum alloy casting cap, one can effectively prevent the magnetic flux leakage, two aluminum heat dissipation is good.
2. The characteristics of automotive generator
1) improves the magnetic circuit and rectifiers eight, increasing the output power.
2) rectifier and the electronic regulator are housed within the generator.
3) a charge indicator, reduced self-excited generator speed.
4) a brushless configuration, the generator structure is simplified, thereby facilitating maintenance.