What are the techniques and skills of automobile maintenance?

If your motor often gets hot, it will get hot after riding for a short distance, which is beyond the normal temperature range, so it needs maintenance. So should Ruhe be repaired? The following is the car maintenance technology compiled by iTV Bian Xiao for you, hoping to help you.

The technology of motor maintenance first, the internal fault of motor. The internal fault of the motor may cause the motor to heat up for the following reasons:

1, because of the bearing, the bearing bears the rolling speed. Once the steel ball gap increases, it will cause the motor to sweep inside and the stator will rub against the rotor, which will make it difficult to raise the temperature, increase the friction and raise the temperature.

Solution: Replace the high-quality bearing.

2. Stator deformation. In order to reduce the cost, some motor manufacturers have poor stator rigidity, easy deformation, deviation from the normal track when rotating, uneven stress and rising temperature.

Solution: Replace the stator with good rigidity.

3, caused by the coil. Pure copper wire winding not only saves electricity and can't afford heat, but also has strong power. However, the appearance of copper-clad aluminum and aluminum-clad copper in the motor market will cause the motor temperature to rise. The heating of the motor is also related to the thickness of the motor turns. The internal material of the coil is different, so the power, electricity consumption and heating degree will be different. The thinner the wire, the greater the heat generation.

Solution: Replace the pure copper stator.

4, caused by magnets. The magnetism of magnetic steel will make it more efficient, stronger in strength, stronger in power, safer in driving and more stable in performance, but some magnetic steels are not up to standard, weak in magnetism and easy to demagnetize, and demagnetize quickly when driving at high temperature. The longer the time, the higher the temperature, the faster the demagnetization, and the vehicle power is insufficient and weak.

Solution: Replace the high-quality magnetic steel sheet or replace the motor.

5. There is water inside the motor. Not every motor is well sealed. Water goes in, it's easier to go in than to come out. Even a motor with water may be able to ride, but the arrival of water will affect the efficiency of the motor, resulting in a decrease in motor power and an increase in temperature.

Solution: clean up the inside? Water? , do a good job of sealing.

Second, the controller problem. The controller adjusts the speed of the motor by converting electric energy into current.

Fever is normal. Both the motor and the controller have large current during operation, so they must dissipate heat through the housing. No fever means it's not normal, overheating is the problem. The controller controls the current, which will also increase the temperature of the motor when the car is overloaded or difficult to ride. However, there is a fault inside the controller, which will also cause the motor to heat up. In addition, the mismatch between the controller and the motor will also cause heat, and the small controller of the motor will damage the motor and the power to control the small motor is insufficient. It is recommended to use as large a controller and as large a charger as possible.

Third, the problem of the brake system. The heating of friction motor in electric vehicle braking system may be caused by the following faults:

1, the brake line does not return. Due to the long-term use of the brake line, both ends of the brake line are corroded by water or the bottom of the brake line is scratched, which will make the brake ineffective and the motor temperature rise.

2. The brake pads are worn. Some customers' brakes are not very good, and they are very tight, and even very tight at last, which leads to the increase of friction between brakes and motors and the increase of motor temperature.

3. The brake spring is broken. It is difficult to make the brake pad spring in place by external spring, and the spring has damaged the brake pad. Close? Do not rebound, so that braking will promote rolling resistance, so that the temperature of the motor will rise.

Repair method of inter-turn short circuit of motor winding 1. Check and find the short circuit point. Detect the phase-to-phase, turn-to-turn and grounding fault points of motor windings respectively, and find out the winding fault points. In general, the winding of motors above 160KW is made of flat copper wire with glass fiber color, and the short-circuit current at the fault point is very large, which is several times of the normal working current. So the fault point can be seen intuitively. If you can't see it intuitively, you can use a double-arm bridge to detect it.

2. Take out the short-circuit coil by heating. After finding out the fault point, put the closed electric furnace plate on the core of the fault point for heating. The power of electric furnace plate is above 2KW. According to the power of the motor and the length of the iron core, it is decided to use several heating electric furnace plates for heating.

The heating time depends on the size of the motor, as long as the temperature reaches the point where the slot wedge of the motor can be pulled out after softening. After pulling out the slot wedge, take out the winding insulation paper separately with a special slot cleaning shovel, and then take out the winding flat copper wire coil with short circuit between turns. As long as the temperature is properly controlled, it is easier to take out the old wire part.

3. Clean the ditch. After the faulty flat copper wire is taken out, the original insulating material of the groove is removed in the hot state. The metal melting point of iron core breakdown caused by turn-to-turn short circuit can be removed with an electrician's chisel tool, and then deburred with an angular grinding wheel or a file until smooth.

4. Weld the new coil. The turn-to-turn short circuit point of flat copper wire is in the straight part of the slot or at the two ports of the magnetic slot. The welding points of the new copper flat wire replaced locally are all on the prismatic straight lines at both ends. If multiple wires are damaged and replaced, the welding points should be separated by a certain distance to form trapezoidal welding.

Before welding, file the welding points of the welded copper flat wire into a groove butt joint with a flat file, and weld with gas welding. It is best to choose a small gas welding torch and use a welding wire with high silver content for welding. When welding, separate the winding coils with heat-resistant asbestos board to avoid burning the winding. After welding, use a flat file to file the burr or excess metal at the welding place to the size of flat copper wire.

5. Insulation treatment and embedding.

The flat copper wire formed by welding is covered with two layers of glass ribbon. Add 0.5 mm thick glass fiber slats between turns or phases. The trench insulation adopts 0.35mm DMD composite insulation material. The replaced flat copper wire is colored with glass fiber, coated with 1032# insulating paint, and then properly heated to be non-sticky and embedded in the groove. The groove is made of glass fiber slats with a thickness of 2mm.

6. Try it before drying and painting.

After the insulation between phases, turns and ground is qualified, the varnish shall be subjected to pressure test before drying. The withstand voltage of the test is 2UN+ 1000 volts, and the test time is 1 minute. Phase-to-phase and grounding withstand voltage shall be conducted once each.

The stator parts are dried. Our self-made drying box, the drying temperature is 100℃, and after four hours of constant temperature, the whole winding is dipped in paint, and the model of insulating paint is 1032#. More varnish should be poured on the local repair parts, and it must be soaked thoroughly. After painting, secondary drying is carried out. Dry at 100℃ for four hours.

After drying, after the motor is cooled, at room temperature, the withstand voltage test after painting is carried out again. The withstand voltage is 2UN+1 000V1min. After the withstand voltage test, the insulation to ground and interphase can reach 150M? Above.

How to repair the motor 1 after water inflow? If the motor wheel of an electric car is made of aluminum, blow dry the water with a hot air gun to evaporate the water! If the surface of magnetic steel is oxidized and rusted after being wetted, give it to the motor? Internal force? Large loss leads to large discharge current and motor heating, which wastes electricity! After a long time, sludge and rust will gather, and the bearings inside the motor will be easily damaged and swept away! The increase of motor current riding has a negative impact on the shortening of continuous mileage, and the large motor friction will cause the whole vehicle parts to run hard!

2. Dry the accumulated water in the stator winding with a hot air gun, and install it when the insulation resistance of the winding is greater than 10 megohm. Pay attention to Hall when the hot air muzzle blows the stator, and don't let the high temperature turn Hall over? Dissolve, otherwise the water will dry up and the installation and operation will be abnormal!

3. Observe whether the two end covers of the motor are rusted, stuck or influxed, resulting in inflexible rotation. What if it doesn't work? Properly lubricate and replace it in time if necessary to avoid bearing damage to the motor. Steel eggs? Fall off and break the coil, resulting in scrap!

4. It is best to apply sealant around the motor end cover to avoid secondary damage caused by lax sealing! Check the motor end covers on both sides of the motor? Oil seal? Is it completely closed, so that water can enter as seamlessly as possible!

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