Rewinding anchors: an amateur experience. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Electric motors

 Comments on the article

Where does the rewind start? Of course, from checking the ED for performance. To begin with, the ED is connected to a supply voltage source. If the armature shaft of the DC EM is stationary or rotates slowly, then the armature may be faulty. However, there may be other reasons, for example: jamming of the shaft with rust, "broken" bushings, wear of the brushes and commutator, sagging of the springs, dry grease. To determine the cause of the malfunction, disassemble the ED. Black wire with crumbling enamel at the anchor indicates a malfunction of the anchor. If visually the anchor looks good, then you need to check it with a special anchor tester, for example, E-236.

In the absence of such a device, an ohmmeter (preferably electronic) measures the resistance of the windings between the collector plates. The downward difference in the resistance of some windings indicates an interturn short circuit, a very high resistance indicates poor contact at the points of attachment or soldering of the winding wire to the collector plates, and the absence of ohmmeter readings for a break in the winding. Unfortunately, it can be difficult to determine such an armature malfunction as an interturn short circuit due to the large cross-section wire used in the windings and the small number of turns. If it was not possible to detect a malfunction, but doubts remained, it is possible to assemble an ED with a known good anchor.

To measure the breakdown of insulation on the housing, measure the resistance between the collector plates and the armature shaft with an ohmmeter. If the insulation resistance is below 10 kOhm, then the armature is considered broken. When connecting an electric drill, a vacuum cleaner, a mixer to a power source, outwardly, armature malfunctions manifest themselves in a decrease in speed, strong sparking of the brushes ("all-round fire"), significant heating of the armature, in the absence of a reaction to the connection of voltage and the presence of a smell of burnt insulation. A detailed check begins with a gearbox, a switch, a speed controller, brushes, as well as spark and noise suppression capacitors, with a check for a break in the wires, bearing defects. After that, the device is finally disassembled and the anchor is checked. The test methods are the same as for DC EM armatures. A typical malfunction only for AC EM armatures is mechanical damage to the winding by foreign particles that have entered through the ventilation holes.

The defective armature is prepared for rewinding. At the same time, the diameter of the wire is measured with a micrometer (first with enamel, then without enamel), the number of turns in the section is counted, the winding method is determined, as well as the order of connecting the windings to the collector plates. The obtained measurement results are compared with reference data and the closest value is selected. The fact is that when measuring, an error is almost always introduced due to a deformed wire (even after careful alignment) and the impossibility of perfect stripping. In ED used in automotive technology, the remaining parameters are determined when unwinding the armature windings. All data is recorded in detail, and the winding scheme is also drawn. Such measures protect against possible errors.

It is more difficult to determine the winding parameters in the anchors of household appliances: the windings are impregnated with a special varnish to improve the quality of the insulation and fix the turns, which prevents the winding of the turns during disassembly and leads to a break in the thin wire. In this case, the leads soldered to the collector are disconnected and the beginnings and ends of the windings are determined using an ohmmeter. If the measurement failed to find out the winding circuit, then the winding is unwound using an adjustable voltage source from 0 to 12 V. To do this, voltage is applied to the beginning and end of one of the windings and slowly increases it until the winding wire starts to heat up. With the right choice of voltage, the wire easily softens the varnish without overheating.

Unwind the wire with tweezers, timely removing the excess wire. To remove the old winding, the frontal and rear parts of the winding protruding from the iron are cut off with a cutting cutter on a lathe or a hacksaw. The remaining wire is knocked out of the grooves with a round metal rod. The diameter of the rod is selected so that it passes inside the groove with a minimum clearance, without jamming. In some cases, to facilitate the removal of residual wire, the armature is heated.

After the final cleaning, the end insulating linings are restored. Broken off pieces of plastic overlays are glued, and burned-out cardboard ones are made new. To facilitate the laborious operation of cutting out a complex profile of the lining, it is simplified. A cut out cardboard circle with a hole punched in the center is put on the armature shaft and glued to the iron. On the finally glued overlay, unnecessary areas located above the iron grooves are burned with a hot nail. From the side of the collector, the patch for gluing is cut into two parts. Further, inserts from a special cardboard (pressboard) are inserted into the grooves of the iron, which are necessary to isolate the wire from the iron. The insert is cut in such a way that when placed in the groove, its edges protrude outward by 5 mm. DC ED used in cars are less demanding on the quality of insulation. It is acceptable to use any thin cardboard, even paper.

The winding circuits of most automotive EMs are simple, so there are usually no problems when rewinding, which cannot be said about the winding circuits of household appliances.

Fig. 1 shows a diagram of winding the armature of a vacuum cleaner, Fig. 2 - a drill, Fig. 3 - a mixer.

As you can see, one section can have from one to three windings. This factor determines the number of simultaneously wound wires. If there are three windings in the section, then three coils of wire are needed, etc. When winding, labels are used to indicate the beginning and end of each winding. In order not to get tangled in the wires after winding, all coils are numbered and labels are attached according to these numbers. The numbering order on the labels is: "n 1,1"; "to 1,1"; "n 1,2"; "k 1,2", where the letters "n", "k" are the beginning and end, the second digit is the section number, the third digit is the winding number.

Winding the armature of a mixer with this type of winding, as in Fig. 3, is more difficult. It uses a thinner wire, twice as many turns and continuous winding. To facilitate winding, a special "needle" is used. It can be made from a plastic fountain pen without a stylus. A simple refinement consists in piercing a hole in the back cover and gluing a cambric 5 ... 7 mm long into the front of the fountain pen. The wire is passed through the "needle" from behind. Winding is somewhat reminiscent of sewing.

To seal wires in grooves, when winding anchors, it is convenient to have two sticks (one round stick, in the form of a nail, and the other flat, in the form of a ruler) made of non-metallic material (plastic, textolite, wood).

If there are three windings in the section, then winding is done with three wires at once. Usually the direction of winding is from left to right, in the opposite direction it is less common, but this option should be kept in mind when determining the winding scheme. In this case, the error is detected too late, only after the assembly of the ED. It manifests itself in the rotation of the anchor in the opposite direction. In this case, you can try to remedy the situation by swapping the wires connected to the brushes.

To protect the enamel of the wire from damage, the protruding edges of the pressboard are pressed against the corners of the armature slot before winding. After winding is completed, these edges are cut off and tucked into the groove with a flat stick. For the final fixation of the wire, textolite wedges are carefully hammered into the groove. So that the wedges do not crush the pressboard when driving, sharp corners are cut off at the lower edges, and the edge facing the winding is sharpened obliquely.

A thick thread is wound into the space between the collector and the iron of the anchor to the level of the collector. Next, with the device shown in Fig. 4, grooves are cut at the edges of the collector plates. A piece of a hacksaw blade is inserted into the fixture for cutting metal. The width of the groove is adjusted by turning the sides of the cutting blade on the grinder. Soldering wires to the collector is carried out with a soldering iron with a power of at least 65 watts. The edge of the soldering iron tip must be sharpened to the shape of the groove.

Thanks to this sharpening, the grooves are easily tinned and the wires are pressed into them. Solder is used with the highest possible refractoriness. In order not to strip it when tinning the wire, apply the wire to a wooden plate with pre-melted rosin and tin it.

To fix the wires soldered to the collector, wrap them with a strong thread. At the end of the work, the windings are covered with epoxy glue. Textolite wedges are also fixed in the grooves with this glue. It is not recommended to use furniture varnish instead of epoxy glue, as it worsens the insulation, so it is better to use a special varnish for electric motors. After impregnation with this varnish, the product is dried in a thermal oven.

Author: S.M. Usenko

See other articles Section Electric motors.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive AI was taught to distinguish between the eyes of the living and the dead 28.07.2018 Researchers at the Warsaw University of Technology have developed a machine learning algorithm capable of distinguishing between the irises of living and dead people with 99% accuracy. Scientists trained artificial intelligence using a database of irises of people who died at different times, as well as samples of the irises of hundreds of living people. The researchers then made the system interact with eye images that the algorithm had not been trained on. The eyes of dead people are usually held by retractors, so the university staff had to cut out everything except the irises themselves from the sample images so as not to mislead the algorithm. The Polish researchers had to photograph living irises with the same camera used to shoot the eyes of corpses so that technical differences would not spoil the result. There is a catch in this approach: the algorithm is only able to detect a dead eye if its owner has died 16 or more hours ago - the difference is insignificant in the first few hours. Theoretically, an attacker could kill someone, open the victim's eye and unlock their smartphone. However, thanks to the system, the killer would at least have to hurry.

Other interesting news:

▪ Serial Electric SUV Smart #1

▪ Smart Air Seats

▪ flying squid

▪ Beta Music Audio Systems by Infinity

▪ The air in the subway destroys the human body

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site RF power amplifiers. Article selection

▪ article "whole" and "part". Encyclopedia of visual illusions

▪ article Which Russian emperor believed that Americans eat human meat? Detailed answer

▪ article Head of diving operations. Standard instruction on labor protection

▪ article Prefix to the oscilloscope. Encyclopedia of radio electronics and electrical engineering

▪ article Passive tone control with variable inflection frequencies classic. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024