Repairing the Bulgarian Bosch with your own hands

Angle grinders( Ushm, Bulgariks) under the German brand Bosch are distinguished by high quality, reliability anddurability. The main competitive advantage of Bosch angle grinders is the wide use of innovative technologies in the manufacture of the product.

But German quality can not resist Russian negligence. Incorrect use of the tool, untimely replacement of grease, carbon brushes, bearings leads to the failure of the tool.

In order to repair the Bosch angle grinder, you can go in two ways: to give the Bulgarian to the service center or to repair the Bosch grinder with your own hands.

The first option is more expensive and not always of high quality. The second option can be implemented only if the consumer has a great desire to figure it out on his own.

The scheme of the Bulgarian Bosch will help you to repair yourself.

Bosch Bulgarians are conventionally divided into low power up to 1000 W, and powerful ones over 1000 W are marked GWS 7-125, GWS 20-230 or others.

stands for

The first figure of 20 or more indicates the power of the instrument is more than 1000 watts. The second digit 230 certifies that this is the maximum diameter of the cutting circle.

The first figure up to 20 indicates the power of the instrument to 1000 W, and the second one about the maximum diameter of the cutting disc to 125 mm.

Design features of Bosch

angular grinder Bosch design feature of the Bosch grinder is used in the gearbox as a bearing for the driven helical gear of a needle bearing. In Bosch perforators, the driven gear on the spindle shaft is fixed by pressing.

In Bosch small power Bulgarians, in which gears are fitted with spur gears, installation of adjusting shims is provided. This design allows you to restore the operability of the pinion contact, reducing the thickness of the gasket. Helical gears with high tool speeds wear out much less than spur gear.

The working environment of Bulgarians is often a dusty space. Dust represents the main danger, leading to the failure of power tools, amorous and Bulgarian.

Repair tool

To repair the Bosch grinder, you can not do without a tool. Immediately make a reservation, if you have a screwdriver, it will greatly speed up the process of disassembly and assembly of the instrument.

But you can do with a set of screwdrivers, preferably with a ratchet mechanism. Do not do without a car key, which will unscrew the fastening nut of the leading helical gear.

For dismantling of bearings it is better to have a special puller.

The diagnostics of the electrical part can be carried out using a tester or short circuit test device.

It is especially useful in that it allows you to determine the malfunction of the rotor or stator without removing the knot.

The scheme of the Bulgarian Bosch will help you to repair yourself, but this instruction will help to adequately cope with any problem.

Bosch disassembly by Bosch

For the owner of the power tool, knowledge of his device and the ability to disassemble is a must.

Knowing the order of disassembly of the grinder allows you to perform such work yourself as replacing grease, changing bearings and carbon brushes.

To disconnect the gearbox housing pos.821 from the stator housing pos.888, it is necessary to disassemble( remove) the handle of the grip handle pos.24.

This operation must be carried out in order to get the carbon brushes pos. 810 holding the rotor manifold.

In the second stage, unscrew the four( four) screws of pos. 61, which secure the gearcase and stator housings.

After pulling the rotor together with the reducer, start disassembling the gear unit.

Repair Bosch Bosch begins with the disassembly of the gear pos. 8221.Disassembly of the gear unit begins with twisting 4( four) screws pos. 60.As a rule, at the factory screws are screwed on the sealant. We will have to make some efforts.

Just note! Low-power Boschs in the reducer use spur gears. Bulgarians with a power of over 1000 W in gearboxes use helical gears.

How to remove the driven gear

After removing the gearbox cover, you can get the helical gear assembly pos.26.

To remove the gear, you need to use a press or puller. But using a stripper is difficult, because it requires the use of special thin sponges.

Before removing the helical gear, check the toothed joint play, tooth integrity, contact spot.

The bearing of pos. 50 is pressed on the spindle shaft pos.26.If the bearing has a large clearance, noisy when scrolling, the lubricant has dried out, it is preferable to replace it.

To remove the bearing, it is necessary to remove the pinion, lock ring and disassemble the bearing. If, while dismantling the rotor shaft assembly, the bearing remains in the gearbox housing, the bearing is dismantled using a hammer and a soft pad.

How to remove the driving pin of the Bosch

Bosch

The pinion gear pos. 27 is removed from the rotor shaft in the following sequence:

• Press the rotor with your hand and unscrew the nut pos. 45 clockwise with a wrench;
• Remove the washer pos. 59.;
• Pull out the leading helical gear pos. 27.

Check visually the integrity of the gear teeth, contact patch.

If the gears are badly worn( licked), there are chipped teeth, they must be replaced. Moreover, the replacement of gears is always made in pairs.

In Bosch low-power Bosch, the needle bearing is used as a bearing in the gearbox.

Repairing Ushm bosch with your own hands, follow the enclosed instructions. If you need to remove the needle bearing from the housing, you can not do without wit. Its dismantling is carried out only with the destruction.

In order to get the collapsed bearing ring, you can use the proven method.

A tap is selected with a diameter slightly larger than the inside diameter of the collar of the destroyed needle bearing. The tap is fastened in the socket of the screwdriver and screwed cautiously at low speed into the cage. When the tap reaches the bottom of the gearbox housing, it will begin to lift the clip.

In addition to the needle bearing of the spindle shaft, in Bosch Bosch two more bearings are mounted, mounted on the shaft of the rotor.

How to remove the bearings from the rotor of the Bosch

Bosch

It is recommended to use pullers to disassemble the bearings from the rotor.

Bearing pos. 15 near the collector is easily removed, but to remove the bearing pos.14 from the side of the impeller is complicated by the fact that you need to perform a number of preparatory operations.

The bearing pos. 15 is closed with a soft rubber socket. A similar rubber protection pos.33 covers the bearing pos.14.

To disassemble the bearing pos.14, unscrew the nut pos.45, remove the straight gear pin 17 and the plastic protection pos.33.Using the puller, it is easy to disassemble the bearing from the rotor shaft.

And if there is no puller? Vices, two metal strips and a hammer with a soft metal insert will come to the rescue.

Disassembly of Bosch

Possible electrical faults

The electrical components of the Bulgarian Bosch can be divided into simple and complex ones.

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Simple malfunctions of the electrical part of Bosch

If you turn on the bulgarka and it refuses to work, start looking for a malfunction with a break in the power supply wire. Most often, a wire break occurs at the entrance to a bulgarian or fork. Do not allow twists, this will lead to a short circuit in the tool.

To determine such a malfunction, it is necessary to open the covers of the grip handle. In Bulgarian Bosch up to 1000 W the lid is attached with one screw in the end. For Bosch Bulgarians over 1000 W, the handle cover is fastened with several screws.

Using a tester, call the power circuits from the input plug pos. 5 to the switch. With an entire circuit, go to check the operation of the switch. Bosch grinders use simple switches controlled by the switch lever.

But the electrical contacts of the switch burn up and cause the failure of the Bulgarian. It is not advisable to restore the contacts of the plastic switch, it is necessary to change it to a new one.

If the switch is intact, use a tester to check the presence of a chain from each plug pin to each carbon brush. For whole chains, the bulb must turn on. If it does not rotate, then the fault is in the mechanical part. It is possible to jam gears or destroy bearings.

Checking the electric motor

If your Bulgarian Bosch is gaining momentum regardless of you, it starts to get warm, spark, you need to pay attention to the integrity of the windings of the rotor, stator.

The involuntary set of revolutions of the ushm indicates a malfunction of the stator windings. The integrity of the windings is checked by the tester, and the short circuit between the turns is checked by a special device.

How to determine the malfunction of the

rotor The repair of the rotor is a complex technological process, accessible to the masters with straight arms.

The malfunction of the rotor is indicated by the drop in engine speed, the appearance of a long sparkling trace on one of the brushes. This is the first sign of short-circuiting the windings of the armature winding.

Repair of the rotor is preferably carried out in special workshops. And you can rewind yourself, if you decide to repair the Bosch by yourself.

The dark color of the rotor winding and the burnt lamellas of the collector indicate a short circuit in the rotor circuits. The fault is only removed by replacing it with a new rotor.

Repair of stator

Repair of the angle grinder bosch includes the restoration of the stator. The main sign of the failure of the stator is spontaneous increase in the speed of the working bulgarka, which can not be reduced by adjustments. The burnt stator winding changes color, it becomes darker. The stator core from the heat also darkens.

Stator rewinding is easier, although here you must follow certain rules and consistency.

If you removed the stator housing cover, carefully inspect the state of the carbon brushes and the rotor collector sipes.

The length of carbon brushes must not be less than 8 mm. By the way, in Bosch, Bosch uses carbon brushes with a "shot", a device that stops the work of the Bulgarian with the minimum length of the carbon brush.

The collector louvers must not have any deposits of cinders or wear. The carbon is easily removed with cotton wool soaked in alcohol.
Stator overheating and short circuit of the rotor

Malfunctions of the

speed regulators In the Bosch series, especially low power, the speed regulators are installed. Access to the speed controller is done by opening the handle of the stator housing, which is held on one end screw.

The speed range of the regulator can be set with a potentiometer hidden in the handle panel.

The defective regulator is easy to remove, since it is attached only to the guide.

Repair of the rotary speed controller is a complex process, the performance of which requires not only special knowledge, but tools and equipment.

If the speed controller fails, and there is no new one, then disconnect the supply wires and install a jumper.

Red indicates the jumper, which is set when the speed regulator is out of order.

Mechanical Damage

Angle grinder Bosch is designed for cutting, grinding, polishing. The work of the tool in dust at high loads especially detrimental to the life of the gearbox, namely its gears.

In addition to wear and breakage of gear teeth, mechanical failure can be attributed to the destruction of bearings and housings. Repair Bosch Bosch in part of replacing the failed bearings, the restoration of the hull is easy to perform, if there is a desire and need.

Assembly of the Bulgarian

The assembly of the Bulgarian starts with a survey of all parts, components, bearings, gears.

Prepare a workplace with correct and good lighting, put tools, lubricants, napkins.

What kind of lubricant to use for Bosch Bosch

Repair of Bosch's ears will not be of high quality, unless you change the lubricant when it is made. For high-quality lubrication of the Bosch grinder units, it is recommended to use the lubricants offered by the tool manufacturer. But their high price forces us to look for another way out, and it is there.

Domestic manufacturers of lubricants have developed special lubricants for reducers and knots of Bulgarians.

For quality, they are in no way inferior to foreign lubricants, but are much cheaper. The only negative, our lubricants require more frequent changes.

And you can use a lubricant made by yourself.

Assembling the rotor

Assembling the rotor consists in pressing the bearing on it, installing the impeller. The lubricated bearings are pressed onto the shaft using a wooden board. The bearing near the collector is closed with rubber protection. This is a general algorithm for assembling the rotor shaft.

In some models Bosch Bosch has its own characteristics.

ASSEMBLY ASSEMBLY

The gearbox assembly begins with the rotor shaft housing installed in its housing. When the shaft is inserted into the housing, the drive pinion, washer and lock nut are threaded onto the shaft. The gear housing with the shaft inserted must be located in the stator housing.

When you insert the manifold bearing into the socket, press the gearbox housing against the stator housing. Check the ease of rotation of the rotor in the bearings.

A spindle assembly with a fitted bearing and gear is mounted in the gearbox housing cover.

It remains to insert the cover into place and check the rotational speed of the spindle shaft. If the shaft rotates easily by hand, it is fashionable to twist the screws securing the rotor housing cover. Beforehand, the screws are lubricated with a sealant.

This is a general algorithm for assembling the gearbox. In some models, the repair of the Bosch reducer is slightly different.

Conclusion:

• Knowing the general scheme of Bulgarians Bosch, you can safely take up the dismantling of the tool for lubrication;
• Ability to repair the Bosch grinder with your own hands will help prolong the life of the tool, replace the lubricant yourself, coal brushes;
• Observing the operating mode and technological maintenance of the tool, you will prolong its trouble-free operation for many years.

Success in work!

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