The car generator is an important presence in the car. The synchronous generator works based on the principle of electromagnetic induction. It converts mechanical energy into electrical energy through the relative movement of the magnetic field of the rotor and the stator winding. When the rotor is driven by an external force, the magnetic field of the rotor and the stator conductor move relative to each other, that is, the conductor intersects the magnetic field lines, from so that an induced electromotive force is generated in the conductor and its direction can be determined according to the right-hand rule. So, what are the reasons why the automobile generator is not producing electricity?
What are the reasons why the car generator does not produce electricity: The generator is overheated
(1) The generator does not work according to the specified technical conditions, such as THEstator voltage is too high and iron loss increases; the load current is too large, and the copper loss of the stator winding increases, which slows down the speed of the cooling fan, affecting the heat dissipation of the generator; the power factor is too low, which increases the rotor excitation current, causing the rotor to heat up. Check whether the monitoring instrument indication is normal. If this is abnormal, necessary adjustments and treatments should be made to operate the generator according to the specified technical conditions.
(2) The three-phase load current of the generator is unbalanced, and the overloaded single-phase winding will overheat if the difference between the three-phase current exceeds 10% of the rated current; This is a serious phase current imbalance. Unbalanced three-phase current will produce a reverse magnetic field, thereby increasing losses and prcausing overheating of components such as pole windings and ferrules. The three-phase load must be adjusted to keep the current in each phase as balanced as possible.
(3) The air duct is clogged with dust and ventilation is poor, making it difficult for the generator to dissipate heat. Dust and grease in the air duct must be removed so that the air duct is not clogged.
(4) The inlet air temperature is too high or the inlet water temperature is too high and the chiller is blocked. The inlet air or water temperature must be lowered to eliminate blockage in the cooler. Before the fault is cleared, the generator load must be limited to reduce the generator temperature.
(5) Too much or too little grease is added to the bearing. Grease must be added in accordance with regulations, gusually 1/2 ~ 1/3 of the bearing chamber (the upper limit is used for low temperatures). speed, and the upper limit is used for high speed). lower limit), and must not exceed 70% of the bearing chamber.
(6) Bearing wear. If wear is not significant, the bearing may overheat locally; if wear is severe, the stator and rotor may rub against each other, causing the stator and rotor to overheat. Bearings should be checked for noise. If friction between the stator and rotor is detected, the machine should be stopped immediately for maintenance or replacement of the bearings.
(7) The insulation of the stator core is damaged, causing a short circuit between the leaves, causing an increase in local eddy current loss in the core and heat generation. In severe cases, the stator winding will be damaged. damagedage. The machine must be stopped immediately for maintenance.
(8) The parallel wire of the stator winding is broken, causing the current of other wires to increase and generate heat. The machine must be stopped immediately for maintenance.
What are the reasons why the car generator does not generate electricity: abnormal performance
1 When the engine is running or driving normally, the instrument charging indicator light continues to light up.
Causes of breakdowns and troubleshooting
1. Troubleshooting if the generator drive belt is loose or worn: Adjust or replace the generator drive belt.
Check and adjust the generator drive belt:
p>①Visually inspect the generator drive belt for excessive wear, worn curtains, etc. If there is a problem, replace the generator drive belt.
② Check the voltageion of the generator drive belt. A drive belt that is too loose will cause slipping, and a drive belt that is too tight will affect the life of the generator bearings. To check the drive belt tension, you can use your fingers to press hard on the drive belt between the two pulleys. If the degree of reduction of the transmission belt is about 10mm, the tension is generally considered appropriate if the amount of reduction; is too great, the tension will be insufficient, resulting in slippage if the drive belt is almost. If there is no reduction, the drive belt is too tight. Adjustments are necessary. 2. Troubleshoot loose wire connections or short circuits: Check wire connections between generator and battery terminals, reinstall and lock nuts to wire terminals.
3. Troubleshooting when the main fuse is blown: Replace the main fuse.
4. Internal generator faults usually occur at the voltage regulator. Troubleshooting: Repair the generator.
5. Troubleshooting poor grounding: Check the ground wire between the negative battery terminal and the car body, reinstall and tighten it.
6. Battery Damage
I often hear that generators need to be maintained. How to maintain the car generator?
After the engine floods, initial corrective measures should be taken according to the specific situation to avoid secondary damage to the vehicle, discover the key to the problem, and minimize damage to the car. .
After understanding the specific situation, if you find that water has entered the engine, you should remove the spark plug and artificially preventnt start the fuel and ignition system, so that the water in the engine can be drained successfully.
Once the inspection is complete, use compressed air to treat the electrical connections inside the motor to prevent water from corroding them.
The parts to pay attention to are: the fuse box, the sensor socket and the body water accumulation area.
After cleaning, test drive the vehicle to ensure normal engine operation during use.
The automobile generator is an important component of automobile electrical appliances. Its functions consist of two parts: meeting the needs of various power-consuming parts and charging the battery. In order to maintain a stable power generation state of the generator while the car is driving, the following maintenance work should be carried out regularly.
1. AOnce the car has covered some mileage, adjust the generator belt tightness appropriately and reattach the calibration screws if necessary. The generator tripod screws must maintain a certain tightness.
2. Pay attention to the degree of wear of the bearings. If insufficient lubrication is noted, drip a few drops of engine oil from the mouth of the oil cup. otherwise it will affect the power transmission effect.
3. If the straightener is dirty, you can use fine emery cloth to polish it.
4. If the contact surface of the brush is uneven, you can smooth it with a fine emery cloth. When the spring elasticity is insufficient and the brush is excessively worn, new parts must be replaced. If the brush is too short and is not damaged, a gasket can be inserted into the holder to bring it closer to the rectifier.
5. Por insulationte-broom is damaged and new parts must be purchased.
6. The generator poles are loose and must be tightened immediately. If the insulation is poor, they must be removed and repaired.
7. When the generator breaks down halfway and is not too far from the destination, the wires connecting the voltage regulator to the magnetic field coil can be removed. If it is a three-brush generator, the third brush. must be removed so that the generator does not produce electricity. Use battery power for power supply and save as much electricity as possible at that time.
8. The dust ring on the generator must be firm and must not be removed and left unused to prevent dust from entering inside and causing mechanical failure.
9. Clean each wire frequently and keep it dry to prevent leakage.
1. Maintenancen of DC Generator
(1) Generator Disassembly and Cleaning
① Wipe the exterior of the generator and remove the dust cover. hoop, remove the brush wire fixing screw and take out the brush.
② Remove the rear bearing cover and remove the seal, then remove the cotter pin and unscrew the fixing nut.
③ Remove the mounting bolts at the rear end, then lightly tap the rear cover to remove the rear cover and shell.
④ Unscrew the belt pulley fixing nut and remove the belt pulley half wrench and the front cover.
⑤Except for armature coils, magnetic field coils and brushes, other mechanical parts can be cleaned with kerosene or diesel.
If there is oil on the armature coil and magnetic field coil, you can wipe it with a clean cloth or cotton gauze and dry it. Don't clean itnot with non-evaporable oil or alkaline water to avoid damage. to the insulation of the coil.
(2) Inspection and maintenance of the generator
Once the generator is dismantled and cleaned. This needs to be verified. The simple method is to use battery power to connect a test lamp in series, and connect thick copper wires as contact pins at both ends of the wire.
① Check the insulation condition of the negative brush holder.
One stylus can be used to connect to the generator cap and the other to the negative brush holder. If the test light comes on, the brush insulating frame is damaged. If the test light does not light up, the insulation is good.
②Inspection of magnetic field coil.
First open the ground connector of the magnetic field coil, connect the test lamp to the magnetic field via one contact pin, and connect the other contact pin to one endmagnetic field coil tee. If the test light does not light up, the field coil is disconnected, touch the test light to contact the generator box with the other stylus still connected to the field, if the test light lights up, there is has a ground in the coil or terminal. . To further determine whether the link or coil is grounded, remove the field link from the case and connect the field via one contact pin with the other pin still attached to the case.
At this time, the test light is still on, indicating that the coil ground is leaking; If the test light is not lit, it indicates that the insulation of the connection terminal is damaged.
Remove the test lamp and connect the power supply directly to both ends of the magnetic field line. At this time, use a screwdriver or iron rod to approach the two magnetic field coils respectively. two coils must be equal. If thesuction force is inconsistent, the suction force is weak, and the coil is largely short-circuited.
③Inspection of armature coil.
One test pin is connected to either commutator and the other contact pin is connected to the shaft or armature core. If the test light is on, then this indicates that there is a problem with the armature coil and should be checked on the armature coil. Place the armature on the tester and turn on the power, then place a piece of iron on the core and slowly rotate the armature. If the piece of steel jumps on the core slot, it means that the coil in the slot has made one turn. A short circuit or short circuit between the two collector segments, which are connected to the ends of the coils in the slot; after removing the dirt between the commutator segments, the steel plate still jumps, indicating a short circuit between the turns of the coil. After thepower on, use a guide to scrape between two adjacent straightening plates in a horizontal position. If there is a spark, the coil is not shorted; if there is no spark, the coil is disconnected.