Electrical insulating cardboard for the stator grinder. How to rewind the generator without much difficulty. Bulgarian does not turn on

The calculation of the stator winding includes determining the number of stator slots Z1 and the number of turns in the phase of the stator winding 1. In this case, the number of turns in the phase of the stator winding should be such that the linear load of the motor and the induction in the air gap coincide as closely as possible with their values ​​taken preliminarily when choosing the main dimensions, and the number of stator slots provided a fairly uniform distribution of the winding coils.

In order to fulfill these conditions, a preliminary pitch value t1 is selected depending on the type of winding, the rated voltage and the pole pitch of the machine. Taking the rated voltage equal to 380 V, we select the limit values ​​t1, mm, according to table 6-9, t1max=22 mm and t1min=17 mm.

Then the possible numbers of stator slots Z1min and Z1max corresponding to the selected range are determined by the formula 6-16

We take Z1 \u003d 60, then the number of grooves per pole and phase q, we find by the formula

where m is the number of phases, m=3.

Tooth division of the stator t1, mm, finally determined by the formula

t1 does not go beyond the above limits.

When determining the number of effective conductors in the slot UП: in a two-layer winding, it is desirable that it be a multiple of two.

First, we determine the preliminary number of effective conductors in the slot U "P, provided that there are no parallel branches in the winding (a \u003d 2) according to the formula (6-17)

where A is the value of the linear load, A / m;

I1n - rated current of the stator winding, A.

The rated current of the stator winding is determined by the formula 6-18

where U1n is the rated voltage of the stator winding, V, Un=380 V.

Hence, by formula (3.2)

When determining the number of effective conductors in the groove, they are guided by the following: up must be integer, and in a two-layer winding it is desirable that it be a multiple of two. The use of double-layer windings with an odd u is allowed only in exceptional cases, since this leads to the need to make multi-turn coils, which complicates the technology of manufacturing and laying the windings.

Let us take such a number of parallel branches of the winding a, at which the number of effective conductors in the groove will either completely satisfy the conditions given earlier, or require only a slight change.

We accept a = 3, then the number of effective conductors in the groove up is determined by the formula 6-19

Let's take the number of effective conductors in the groove up=16.

The final value of the number of turns in the phase of the stator winding 1 is determined by the formula 6-20

The final value of the linear load A, A / m, is determined by the formula 6-21

The value of the linear load A=54.6 A/m differs from the previously accepted value equal to 55,000 A/m by less than 5%.

The shortening factor ky1, which takes into account the decrease in the EMF of the coil, caused by the shortening of the winding pitch, is determined by the formula 3-4

where 1 is the shortening of the stator winding pitch.

The shortening of the two-layer winding pitch is chosen so that the winding pitch is equal to an integer, and the shortening factor is approximately 1=0.8 at 2p=4

The step of the two-layer winding y1 can then be determined by the formula

The resulting value of the step of the two-layer winding y1 is rounded up to an integer, then we take y1 =12.

We recalculate the shortening of the pitch of a two-layer winding according to the formula

Then by formula 3.7

Let us find the distribution coefficient of the winding, which takes into account the decrease in the EMF of the winding distributed over the grooves in comparison with the lumped winding. It is determined by the formula 3-6

The value of the winding coefficient kb1 is determined by the formula 3-3.

The adjusted value of the winding coefficient is then equal to

The final value of the magnetic flux Ф, Wb, according to the formula 6-22

The final value of the magnetic induction in the air gap V, Tl, is determined by the formula 6-23

The value of the magnetic induction in the air gap of 0.815 T differs from the previously accepted value of 0.82 T by less than 5%.

The current density in the stator winding J1, A / mm2, is preliminarily determined by the formula 6-25

where AJ1 is the product of the linear load and the current density and is determined from Figure 6-16, d, AJ1 = 290 A / mm 3.

The cross section of the effective conductor qeff, mm2, is preliminarily determined by the formula 6-24

The stator winding is made of a rectangular winding wire and placed in rectangular grooves.

Winding wire brand PETP-155 (class F) is selected according to the table. P-29 (Kopylov part 2)

Nominal wire size on the larger side b, mm

Nominal size on the smaller side a, mm

Cross section of effective conductor

Finally, the current density in the stator winding is calculated by the formula 6-27

Correctness control: the current density in the stator winding differs from the specified value by less than 10%.

The winding of a rectangular wire is placed in grooves with parallel walls. The teeth in such grooves have a trapezoidal section, and the induction in them is uneven. We select a rectangular semi-open groove of the stator. We preliminarily accept, according to Table 6-10, the permissible induction in the stator yoke Ba=1.5 T and the induction in the narrowest section of the stator tooth Bz1max=1.9 T.

Then the minimum tooth width bz1min , mm, can be determined by the formula 6-29

where lCT1 is the length of the stator package, mm, equal to the length of the air gap l, mm;

lCT1 = 250 mm,

kС - steel filling factor of the stator package, selected according to table 6-11; kC=0.95.

Stator yoke height ha, mm, determined by formula 6-28

Many household appliances today use electric motors. Their main feature is that they work asynchronously. This allows you to keep a constant rotor speed even with varying loads.

All produced electric motors have different design features. Each modification may differ in the number of poles, the type of rotor, and other components. The technology for rewinding electric motors is done according to a general principle, there may be differences in some nuances.

If the device is out of order, then you need to contact the workshop. In its absence, you can try to rewind the engine at home. It is desirable to have the necessary skills for this, but in general this process is not so complicated in appearance.

"Engines" have two types of winding:

• stator;
• rotary.

Considering that the design and dimensions of the devices are different, it is possible to give general instructions for rewinding motors. Let us dwell on those that are used in household appliances and are powered by alternating current.

Engine inspection

In the event of a breakdown, remove the motor from the household appliance. After cleaning the components, an external inspection of the windings is carried out. The main thing is to determine exactly where the breakdown occurred. Sometimes it happens that the rotor and stator windings burn out. And then they need to be completely replaced.

When a malfunction occurs, the temperature inside the motor housing rises. This leads to a violation of the insulation on all elements. Therefore, in the repair of an electric motor, windings and insulating coatings are replaced.

Preparatory work

First, let's figure out how to properly rewind an electric motor. The first thing to do is to determine the parameters of the wire and the number of turns in the coil. The Internet will help here. On the forums, people discuss similar problems, as well as talk about personal experience, how they rewound engines.

IMPORTANT! It is necessary to find exactly the same model of the device, otherwise, after the repair, the "engine" may not start!

In the absence of the necessary information on the Internet, you can find it out on your own when examining the "engine". With a strong burnout of the “packings”, we find the most complete section of the winding. It needs to be cleaned.

To rid the wires of carbon deposits, use solvents. Now the "coils" should not be spared, they are no longer suitable. If it is not possible to clean the winding with a solvent, then you can burn it.

There are various schemes for rewinding electric motors. Before removing the "coils", you should pay attention to how they are interconnected. And then you can exactly copy their assembly.

The protruding top of the "laying" must be cut off. To do this, we will prepare the appropriate tool, it all depends on the cross section of the wire. The larger it is, the more serious the tool will be needed. The cut part must be divided into separate wires. So it is more convenient to determine the cross section and the number of turns.

Having removed the winding, we check the iron on which it was wound. The steel should be smooth without dents or burrs. Defects can damage the insulating layer of copper wires, which will lead to another breakdown. Therefore, all irregularities should be cleaned with sandpaper.

If there is carbon deposits in the steel grooves, you should also get rid of it. This will help to avoid further difficulties when working with insulation and wires.

How to choose a wire

In order for the power of the electric motor to be the same, a wire with the same cross section as it was should be selected. This will allow you to wind the specified number of turns.

If this cannot be done, then the most approximate cross section is taken. It should be remembered about Ohm's law, the smaller the diameter of the conductor, the higher its resistance.

IMPORTANT! The selection of wires is taken very seriously. Incorrect section will lead to overheating of the motor, the insulating varnish will melt and as a result will lead to a short circuit!

You need to wind the winding using a template that is made independently from cardboard. It must match the size of the hardware. To achieve a neat arrangement of turns, a special wire winding machine is used. That's all it takes to rewind the engine.

Hand laying may have defects. It is possible to lay the wires loosely, which will lead to an increase in the size of the winding, and the difficulties of its installation.

Installation and impregnation

Rewinding the stator of an electric motor with your own hands does not present any particular difficulties. The main thing in this business is accuracy.

IMPORTANT! The insulation inserted into the grooves must not stick out. Therefore, the excess part is cut off, otherwise, during the operation of the engine, it may touch the rotor!

To make complete insulation of all conductive parts, a special varnish is used. On the market, it is presented in a large assortment. But in fact it is divided into two types. The first dries at ordinary temperatures, and the second only after heat treatment.

Check and enable

Before starting the engine for the first time after repair, it must be properly checked. To begin with, all the inserted "coils" ring. This will help to find out if there is a break or poor contact. Between the "laying" the resistance is measured so that when turned on there is no short circuit.

You should not immediately apply 220 V to the engine, it is better to apply a reduced voltage. Let the rotor spin slowly, the main thing here is to find out if the engine is heating up. If everything went well, and there was no smoke, then the engine repair was successful.

On the Internet there are many photos of rewinding engines. This will help beginners visually familiarize themselves with the process.

Photo of the rewinding process of electric motors

If you have determined that the stator has failed in your hammer drill, and you don’t have the money for a new one, or if you want to repair the part yourself, then this instruction is for you. Disassembly of the Makita rotary hammer is so simple that the repair of the Makita 2450, 2470 does not cause much difficulty. The main thing is to follow the advice given in this article.

Each user who has the skills of a locksmith and knows how to handle diagnostic devices can independently perform a repair of a puncher.

Beginning of work

Any repair begins with an external inspection of the faulty part. And how to find a malfunction of the stator of the Makita 2450 rotary hammer? A stator malfunction is most often indicated by the presence of traces of burnt insulation and the appearance of a burning smell. This is the first sign of a short circuit in the stator windings.

Collapsible stator option

But a break can be determined only by ringing the winding circuits.

Algorithm for disassembling and manufacturing the stator of the Makita 2450.2470 perforator

Here is the sequence in the manufacture of the Makita 2450 rotary hammer stator:

1. Extraction from the stator housing assembly.
2. Removing the old winding, determining the winding direction, wire diameter.
3. Winding new coils according to the collected data on patterns.
4. Preparation of insulation for new coils.
5. Insulation of new coils.
6. Installation of finished coils in the grooves of the core or winding coils in the core itself.
7. Soldering the leads to the ends of the coils.
8. Reservation of windings of new coils.
9. Impregnation of wound coils.
10. Stator assembly.

Everything in order

Stage I

Use a wooden hammer or block to disassemble the stator. By tapping on the end of the stator housing, remove the stator from the housing. By the way, to get the stator, it is necessary from the body of the mechanical part.

Don't forget to disconnect the stator lead wires from the terminals that come out in the collector area. One end is attached to the brush holder, and the other end to the wire supplying 220V power.

It's time to split it into two halves.

Stage II

Collapsible stator option

Both halves of the stator are glued together with a thin layer of glue. To separate one from the other, you need to hit the stator core with a mallet. If you got a non-collapsible stator, then the wire is dismantled by cutting all the turns from one end with wire cutters. Having cut, disassembled, take out the wire and measure the diameter of the wire and the number of turns. Use only a micrometer to measure wire diameter. First, the wire must be burned in the flame of a match, wipe the soot and, after cooling, measure.

Most often, the coils are impregnated with an insulating varnish that does not allow the wires to be separated.

Using an industrial hair dryer, heat the coils until they break into separate wires. You can also heat the impregnated wires on a gas oven above the burner.

When disassembling the stator, it is necessary to make measurements. We need to measure the diameter of the wire, the number of turns in one coil, the percentage of filling of the stator slot, the material from which the wires are made. It is recommended to wind only with copper wires.

Wires are classified by section. Having measured the diameter of the wire, recalculate its cross section using the formula S \u003d ηr ², where r \u003d ½d.

And now, in plain language: the cross section is equal to 3.14 times half the diameter squared.

What is this garden for? If it turns out that you have a wire of a different diameter, then you can’t do without calculations. If there is a thin wire, then the winding can be carried out in 2 ... 3 wires, the main thing is that their total cross section is not less than that of the initial one.

If there is a wire of a slightly larger diameter, then it can also be wound with it, provided that the filling of the grooves with the old drive was incomplete.

Stage III

Variant of winding a non-separable stator

To wind the stator coils, it is necessary to prepare a wire of passing diameter, electric cardboard or pressboard, adhesive tape, heat-shrinkable cambric of the desired diameter.

If you have a non-separable stator, then you need to make sleeves from pressboard into its grooves, cutting blanks along the width of the stator.

Blanks are cut from the pressboard with a width equal to the width of the stator and a length equal to the length of the inner groove. By the way, 2 mm must be added to the width of the stator on each side. After cutting the blanks, close their edges with a wide adhesive tape. For the Makita puncher stator, 50 mm wide tape is suitable.

Stick the blank on one side of the tape, cut it. Glue the blanks on the second strip of adhesive tape with the same side, but with a different edge. Your task is to close the edges of the blanks from gusts when winding.

Making fixture strips

To facilitate the winding process by hand, make simple devices, which are strips of soft metal up to 0.8 mm thick. It can be galvanized steel, copper, aluminum. The strips are z-shaped plates 10 mm wide and 70 mm long.

Put a heat shrink tube on the smaller hook of the fixture and heat it over a flame, crimp the tip of the plate.

Fix the resulting plates with adhesive tape on the stator housing.

winding process

The wire is prepared, the fixture plates are fixed, the data on the number of turns is at hand. Forward!

We put the stator on the knee, wind the end of the wire, put a red heat-shrinkable cambric on it (it marks the beginning of the winding), fix the cambric on the outside of the stator and start winding. By the way, the color of the cambric can be any, you just need to choose a different color for the beginning and end of the winding.

The winding process consists of feeding the wire with your thumb into the groove, inserting the wire behind the hook of the fixture plate, pulling out the wire and inserting the plate behind the hook on the other side. Most importantly, keep track of the number of wound turns. The weight winding process is repeated for the second coil.

All this is perfectly visible in the proposed video.

Everything! The stator is wound. It is necessary to carefully link the windings, make a reservation.

StageIV

The process of booking stator windings

Reservation is the binding of the stator coils, which protects them from destruction during operation. At high speeds, various vibrations affect all parts, which leads to the destruction of the integrity of the windings, their friction against each other and the violation of the insulation.

It's time to start drinking.

StageV

Stator winding impregnation process

The main task of impregnating stator coils is to obtain a monolithic structure that does not collapse over time from vibration. Before starting the impregnation, wooden spacers are inserted into the stator, pressing the coils. Work should be done carefully and accurately.

Under ideal conditions, a transformer is needed for impregnation. Impregnation of coils is recommended to be carried out under voltage so that the wires vibrate and warm up. This allows the impregnation to flow into all the cracks. The voltage on the winding is small, until vibration occurs. It can be easily found by leaning a screwdriver against the inner surface of the rotor.

Ideally, use a special varnish and apply it in several layers. You can also use ordinary paint for interior painting in rooms of the PF-115 brand. Pouring 50 g of paint into a separate bowl, dilute it with a solvent to the consistency of water.

Using a syringe, pick up paint and inject in small portions onto the stator coil until it completely penetrates into the middle of the coil. The stator must be warm and connected to an alternating current source. It is better to use a transformer as a source, the primary winding of which is powered through LATR.

Don't forget to monitor the stator temperature. To the touch, the hand can hardly withstand the temperature of the case. At higher temperatures, reduce the supply voltage to the transformer using LATR.

The consistency of the paint depends on the diameter of the wires. The thicker the wire, the thicker the paint. Impregnate until the paint appears at the bottom. Turning the stator over, continue impregnation. Leave the stator under direction until completely dry.

Differences between the new AEG L1220 battery and the old L1215

To understand the difference between new batteries compared to the old version, load testing is required.

Batteries were subjected to a comparative test:

L1215, P/N 4932 3526 58, 1.5Ah, 18Wh, based on cans INR18650-15M L1220, P/N 4932 430165, 2.0Ah, 24Wh, based on cans INR18650-20R Technical data from manufacturer for cans: Battery The new battery is equipped with a protection board: Test results: 1. Compared with the old version of 1500 mAh, the difference in the declared capacity is 33.3%. According to the test results, the superiority of the new battery is more than 50%. Those. the actual difference is greater than stated. 2. A new battery has a lower internal resistance, and as a result: Higher voltage under load - more power output Less power loss to heat the battery. Summary: The new battery based on INR18650-20R cells is noticeably superior to the old version and at a comparable price it is preferable to buy.

From strength of material M(torque) = τ (stress in the rod) * W (polar moment of the section equal to Π*D3/16)

The strength class of the bolt *.* means the following: 1st digit - 1/100 of the nominal value of the tensile strength, in MPa 2nd digit - the ratio of the yield strength to the tensile strength That is, a bolt of strength class 6.8 has a tensile strength of 600 MPa, and a yield strength of 600 * 0 ,8 = 480 MPa The obtained figures are confirmed by the experiment carried out in the training center: the M6 ​​bolt with a strength of 8.8 begins to “float” (irreversible plastic deformations occur) at 17 Nm, and when the torque reaches 23 Nm, destruction occurs. Let's make a similar calculation for screws and self-tapping screws: The full diameter is taken for calculation, the minimum section is much less! Conclusion: To use the most popular fasteners with Ph2 and Pz2 slots, a tool with a torque of no more than 6 Nm for a diameter of 4.2-4.5 mm is required, in rare cases up to 10 Nm for fasteners with a diameter of 5.0 mm. Exceeding the specified torques will damage the fasteners and screwdriver bits. 13 self-tapping screws Ø4.5 x70 mm are twisted into a “pie” 121 mm thick. The moment of 3.0 Nm developed by the Makita DF010DSE screwdriver is enough to confidently screw in the self-tapping screw Ø4.5 x70 mm to its full length. If, in order to prevent the destruction of screws and self-tapping screws, a torque of 2-3 Nm is needed, rarely 5-6 Nm, and in exceptional cases up to 10 Nm, then why is there a torque of 20.30.50 Nm on a screwdriver? What else can a drill/driver do? If a drill means to drill! What torque is needed for drilling? Theoretical digression No. 2. Consider steel drilling as the heaviest metal drilling in terms of load. The torque is calculated by the formula Mkr=10CMDqSyKp, where D is the drill diameter, S is the feed, the other signs are correction factors. For steel with δ=750MPa: CM=0.0345,q=2.0,y=0.8,Kp=1.0 Drilling speed is assumed to be 20-25 m/min (with spray cooling), the corresponding revolutions are entered in 4 -th column. Torque, rotational speed and shaft power are related quantities. The value of the required power on the shaft is entered in the 5th column. Looking at the numbers: Drilling a hole Ø10-13 mm requires a torque of 8-15 Nm. With a recommended drilling speed of 720 -550 rpm, this requires a power of 570 to 850 watts.
What is the power of a cordless drill?

It is not in vain that a conventional drill chuck has 3 holes:
For secure fixation, the chuck must be alternately tightened through all 3 key positions. In a chuck tightened through one hole, a Ø10 mm drill turns at a torque of 13.5 Nm, and through 3 holes (as expected) at 23 Nm. And when drilling steel, a torque of ~ 15 Nm must be transmitted to a drill Ø13 mm. Those. when the chuck is tightened through one hole, the drill will turn! Cordless drill power (consumption) = Battery voltage * current consumption The current consumption for powerful models is 20-25 Amps Thus, the power for a cordless tool will be: For 12 Volts: 240-300W 14.4 Volts: 290-360W 18 Volts: 360-430W The torque for the most powerful (18volt) drill will be: at a speed of 1500-1700rpm: 2-3Nm at a speed of 300-400rpm: 8-14Nm drilling steel with a drill up to Ø7mm drilling steel with a drill Ø10-13mm These are the values torque at maximum power. (in drilling mode) When the engine is overloaded when tightening rigid fasteners (for example, bolts), the torque reaches 30-40Nm. It is these values ​​that are indicated in the characteristics as the maximum soft / hard moment. They have no practical significance! If, when working with a tool, a torque of large values ​​\u200b\u200bis required, then you need a specialized tool specifically for this job. Summary: It is enough for the average user to have a 3-6Nm adjustable ratchet torque in a cordless drill/driver to work with standard fasteners with head sizes up to Ph/Pz2, and up to 10Nm for Ph/Pz3. For drilling steel, plastic, wood with drills up to 10 mm in diameter, a torque of 10-12 Nm is sufficient. Torque above 15Nm requires the use of a specialized tool and should not be included in the scope of application of a universal drill/driver.

Good time of the day guys! Have a question? There is a stator from some grinder with dimensions inside. diameter -42 mm. outer diameter -72 mm height -50 mm. It was wound with a wire of 0.6 mm, the number of turns is -125 (on one winding). I do not have such a section, but there are wires with a diameter of 0.56 and 0.63. What kind of wire can be wound on the stator and how many turns are needed for each wire? If calculated by the cross section, then these wires exceed the allowable 10%. How is the wire and number of turns calculated from the dimensions of the stator? Thanks in advance!!!

In many household devices and home-made designs, low-power electric machines are used as a drive. Despite the high reliability of electric motors, their failure for a number of reasons is not uncommon. Given the relatively high cost of these devices, it is more practical to repair them rather than replace them. We suggest considering the possibility of rewinding electric motors at home.

Types of electric motors and features of their repair

As a rule, commutator DC motors and brushless asynchronous AC motors are used in everyday life. It is the repair of these drives that we will consider. Information about the principle of operation and design features of asynchronous and commutator machines can be found on our website.

As for synchronous drives, they are practically not used in everyday life, therefore this topic is not covered in this publication.

Features of the repair of an asynchronous machine

Problems with any type of engine can be mechanical or electrical in nature. In the first case, strong vibration and characteristic noise may indicate a malfunction, as a rule, this indicates problems with the bearing (usually in the end cap). If the malfunction is not eliminated in time, the shaft may jam, which will inevitably lead to failure of the stator windings. In this case, the thermal protection of the circuit breaker may not have time to work.

Based on practice, in 90% of the failure of asynchronous machines there are problems with the stator winding (open circuit, interturn short circuit, short circuit to the case). In this case, the short-circuited anchor, as a rule, remains in working condition. Therefore, even with the mechanical nature of the damage, it is necessary to check the electrical part.

Winding check

In most cases, the problem can be detected by its appearance and characteristic odor (see Figure 1). If the malfunction cannot be established empirically, we proceed to diagnostics, which begins with a continuity call for an open. If one is found, the engine is disassembled (this process will be described separately) and a thorough inspection of the connections is performed. When a defect is not detected, it is possible to ascertain a break in one of the coils, which requires rewinding.

If the continuity did not show a break, you should proceed to measuring the resistance of the windings, while taking into account the following nuances:

• the insulation resistance of the coils to the housing should tend to infinity;
• for a three-phase drive, the windings must show the same resistance;
• for single-phase machines, the resistance of the starting coils exceeds the readings of the working windings.

In addition, it should be borne in mind that the resistance of the stator coils is quite low, so it makes no sense to use devices with a low accuracy class to measure it, such as most multimeters. You can correct the situation by assembling a simple circuit on a potentiometer with the addition of an additional power source, such as a car battery.

The measurement procedure is as follows:

1. The drive coil is connected to the circuit shown above.
2. The potentiometer sets the current to 1 A.
3. The coil resistance is calculated according to the following formula: , where R K and U PIT were described in Figure 2. R is the resistance of the potentiometer, is the voltage drop across the measured coil (shows a voltmeter in the diagram).

It is also worth talking about a technique that allows you to determine the location of the interturn circuit. This is done in the following way:

The stator, freed from the rotor, is connected through a transformer to a reduced power supply, after placing a steel ball to it (for example, from a bearing). If the coils are working, the ball will cyclically move along the inner surface without stopping. In the presence of an interturn short circuit, it will “stick” to this place.

Features of the repair of collector drives

This type of electric machine is more likely to experience mechanical failures. For example, erasing brushes or clogging of collector contacts. In such situations, the repair comes down to cleaning the contact mechanism or replacing the graphite brushes.

Testing the electrical part is reduced to checking the resistance of the armature winding. In this case, the probes of the device are two adjacent contacts (lamellas) of the collector, after taking readings, a measurement is made further in a circle.

The displayed resistance should be approximately the same (taking into account the error of the device). If a serious deviation is observed, then this indicates that there is an inter-turn short circuit or a break, therefore, rewinding is necessary.

Winding data of electric motors

This is a reference data, so the most reliable way to obtain such information is to refer to the relevant sources. This data can also be given in the passport to the product.

On the network you can find tips in which it is recommended to manually count the turns and measure the diameter of the wire when rewinding. It's a waste of time. It is much easier and more reliable to find all the necessary information by marking the engine, which will indicate the following parameters:

• nominal operating characteristics (voltage, power, current consumption, speed, etc.);
• the number of wires for one groove;
• Ø wire (as a rule, insulation is not taken into account in this indicator);
• information about the outer and inner diameter of the stator;
• number of grooves;
• with what step the winding is performed;
• rotor dimensions, etc.

Below is a fragment of a table with winding data for electric machines of type 5A.

Do-it-yourself step-by-step instructions for rewinding an electric motor

It is necessary to immediately warn that without special equipment and work skills, rewinding coils will most likely be a futile exercise. On the other hand, a negative experience is also an experience. Understanding the complexity of a process is the best explanation for its cost.

The first stage - dismantling

We give an algorithm of actions for asynchronous machines, it is as follows:

1. Disconnect the drive from the mains (380 or 220 V).
2. We dismantle the electric motor from the structure where it was installed.
3. Remove the rear protective cover of the cooling fan.
4. We dismantle the impeller.
5. We unscrew the fastening of the end caps, and then remove them. It is desirable to start from the front part, after its dismantling, the rotor will easily “come out” from the rear cover.
6. We take out the rotor.

This process can be greatly facilitated by using a special device - a puller. With it, it is easy to release the motor shaft from the pulley or gear, and also remove the end caps.

We will not give instructions for disassembling the collector engine, since it does not differ much. The structure of this type of electric machine can be found on our website.

Stage two - winding removal

The sequence of actions is as follows:

1. With the help of a knife, we remove the bandage fasteners and the insulating coating from the places where the wires are connected. In some instructions, it is recommended to fix the wiring diagram, for example, by taking a photograph. There is no particular point in doing this, since this is reference information and it is not a problem to recognize it by the brand of the engine.
2. Using a chisel, we knock off the tops of the wires from each end of the stator.
3. We release the grooves using a punch of the appropriate diameter.
4. We clean the stator from dirt, soot, impregnation varnish.

At this stage, we recommend stopping, picking up the hull and taking it to the experts. Self-dismantling will reduce the cost of restoration work. As mentioned above, it is quite difficult to rewind coils without special equipment. To understand the complexity of the process, we describe its technology, which will make it easier to choose.

Stator rewind (final phase)

The process consists of the following steps:

If only the body was handed over for restoration, we recommend that you check the coils before turning on the motor.

Anchor rewind

The process of replacing the winding of the collector motor is somewhat similar, with the exception of small nuances associated with the design feature. For example, the armature is sent for rewinding, not the case, provided that the problem did not arise with the excitation coils. In addition, there are the following differences:

• For winding, a special machine of a more complex configuration is used.
• It is imperative to turn, balance the anchor (in the final part of the process), as well as its cleaning and grinding.
• Using a special milling machine, the collector is cut.

For these processes, special equipment is required; without it, rewinding electric motors is a waste of time.