Hammer drill zenith pro do-it-yourself repair disassembly. How to perform the correct repair of a perforator on your own. The principle of operation of the percussion mechanism

A perforator is a necessary thing that simplifies work and is even sometimes indispensable for a master. But, like all mechanisms, it can break. If a hammer drill breaks down, there are two options for the development of events: throw away the broken one and buy a new one or try to fix it. The first option may be suitable, provided that the punch is cheap and it is easier to buy a new one. But if the puncher is branded, then buying a replacement may not be affordable. You will always have time to throw it away, but it’s worth trying to fix the puncher yourself. By and large, you risk nothing. Yes, and special skills for repairs are not required. But some nuances still need to be known.

Than something to repair, you need to try to protect the mechanism from breakage. Or at least not aggravate the breakdown of the mechanism. To do this, pay attention to the following points and immediately stop the operation of the rotary hammer:

the smell of burning;
the appearance of unnatural additional sounds;
unstable operation or reduced performance of the puncher.

If at least one of the above points occurs, you should stop work immediately- your perforator requires repair. But before you start troubleshooting the punch yourself, you need to deal with its internal structure.

Perforator device

To repair any mechanism, you need to deal with its internal structure. So, perforators can be of two types:

With engine mounted horizontally.
With vertical motor.

In all other respects, all the details of the perforator are basically similar.

The perforator consists of two parts: electrical and mechanical.

Electric part of the puncher

In some models, the switch is combined with a control device.

The mechanical part of the perforator

Reducer. Mounted on the motor shaft.
Clutch.
Impact mechanism.

Auxiliary mechanisms

Some models may be equipped with additional parts:

mode switch;
a vacuum cleaner;
depth limit;
other.

Trouble-shooting

Do-it-yourself perforator repair has some advantages. Firstly, repair in the workshop is an expensive pleasure, secondly, it can take a considerable amount of time and, thirdly, the breakdown may not be difficult, so it will not be difficult to fix it and soon it will be possible to continue work.

Before proceeding with the repair, the unit must be disassembled. Each model has its own disassembly nuances. But in most cases, any model consists of two parts: front and back halves connected by screws. Before unscrewing them, you need to remove the cartridge. In some models, the cartridge can not be removed.

Possible malfunctions and ways to eliminate them

Malfunctions can also be of two types: those associated with the electrical part of the perforator and mechanical failures.

Electrical faults

It is very good if you have a tester at hand. It will make troubleshooting easier. If this is not the case, you need to review all the electrical parts of the device one by one.

The device does not turn on.

This may be due to a broken wire. Very often the cord breaks near the handle itself.

Elimination method.

Replace the entire cable or shorten part of it at the point where the break occurred. If the gap occurred somewhere in the middle, strip it of insulation, connect the parts, carefully insulate the cord.

Poor contact of the trigger elements.

Such a breakdown can occur due to oxidation or burnout of the contacts.

Elimination method.

Clean the elements or replace with new ones.

Breakage of the extinguishing mechanism.

From a large load, parts of this mechanism simply burn out.

Remedy.

Replace burnt parts. If there are none, then you can connect the motor directly, but it should be noted that with this method of troubleshooting, the wear of the motor increases several times. It is best used only in extreme cases.

Burnout UUD. There are no options - you need to change the mechanism.

Broken winding. Such a breakdown is unlikely to be repaired. Need a rewind.

There are sparks inside.

Sparks may be due to the fact that the brushes do not fit snugly against the armature. Such The problem occurs for two reasons: the brushes are worn out or the brushes are damp as a result of moisture entering the inside of the brush body.

Remedy.

Insert new brushes or dry them and clean them with fine-grained sandpaper.

The appearance of sparks.

This may also indicate the oxidation of the anchor due to moisture ingress.

Remedy.

Clean the anchor. Important do this procedure carefully. so as not to damage the winding. An eraser or cotton swab moistened with alcohol is best suited for this.

Smoke came out of the perforator.

Smoke is coming out of the device due to problems with the brushes. It is important to inspect from time to time, because if they wear off and wires appear on the working surface, this leads to smoke and scratching of the armature. Another cause of smoke can be a seized motor. As a result, the winding heats up and smokes.

Remedy.

Visually inspect all items. If the problem is in the brushes, replace it; if the motor is stuck, fix the problem (there is a description in the mechanical damage below).

Mechanical failures

With mechanical damage, it is a little more difficult: the puncher consists of many parts, so it may not be possible to immediately determine the cause of the breakdown. The main thing, carefully visually inspect all the details, and after identifying the breakdown, carefully eliminate it. Here are the main possible damage that you can fix yourself.

The device turns on, but does not hammer.

Switch. Most devices are equipped with mode switches. This mechanism is prone to failure. If the hammer has stopped hammering, the reason is most likely the worn out switch fingers. During work they are constantly in contact with rotating parts and this leads to wear and tear.
The latch process that holds it in the gearbox housing has broken, which contributes to spontaneous switching of modes. You can not change the latch, if this problem does not bother you, the puncher will still work.

Elimination method.

Replace switch. But if there is no suitable switch, and work cannot be stopped, then you can turn the worn part 180 degrees and you can continue working.

Preventive measures

Breakage is better to prevent, so it is better to adhere to the following recommendations.

Change lubricant twice a year.
Once every six months, a preventive examination of the brushes.
Thorough cleaning every time after work.
Before work, lubricate the back of the drill or chisel to reduce the load on the striker.

If the punch has stopped working normally or a breakdown has occurred, read the instructions and carefully inspect it. Before you start repairing your own hands, really evaluate your capabilities. If you are sure - try to fix it yourself, otherwise, if in doubt, it is better to contact a specialist. And remember that already repaired mechanisms are not subject to warranty and they are reluctantly taken by service centers for repairs.

A rotary hammer is a tool that requires a serious attitude during its operation and disassembly. To do this, you need to know its device, all the nodes included in the design of the tool. Quick orientation in the device and knowledge of how to disassemble the hammer will help to avoid unnecessary expenses both financially and in terms of labor.

A hammer drill, unlike a conventional drill, can easily drill concrete and other durable materials.

Any, even the most insignificant, failure in the operation of the device can lead to breakdowns of a more serious nature. To quickly find a breakdown of the tool will allow its phased disassembly. It is important to know the cause of the breakdown and how to fix it. Disassembling the tool involves following a certain sequence.

Do-it-yourself phased disassembly of a perforator

To begin with, the upper assembly of the perforator is inspected, which is disassembled primarily into its components. All parts are removed in the following order:

Tip.
Washer.
Spring.
Ball.

When the last part is removed, you will need to unscrew all the screws holding the case. Next, remove the overlay on the handle, if any, after which it is required to disconnect each wire from the starter. Then the brush holder is removed.

At the next stage, the gearbox and housing are disconnected until a gap appears through which the switch should be removed. Next, the device should be fixed in a vertical position using a vise. This will allow you to get all the details out of it.

You can use the services of the appropriate service to disassemble the punch. By doing it yourself, you can save a lot of time and money on equipment repairs. During the execution of work, you should follow the step-by-step instructions:

Disassembly begins with the upper assembly, after removing the tip, washer, and at the end - a spring with a ball.
When the ball is removed, you can begin to unscrew the screws that allow you to hold the case.
After that, remove the overlay on the handle, if any, then disconnect each of the starter wires.
Remove the brush holder.
Disconnect the gearbox from the housing until a gap is formed so that the switch can be removed.

The final stage of disassembling the perforator involves vertical fixation of the tool using a vice, then all parts and spare parts are removed from it.

The disassembly of the tool should be done with the utmost care, since it is imperative to remember the locations of individual parts and the sequence in which they were removed. You should choose a special place for them, otherwise they may get lost, rolling somewhere, and the hammer will not be repaired.

What could be the reason for disassembling the perforator

Even if the puncher is in good condition, it still needs to be cleaned periodically for prevention. For this purpose, the device is disassembled, while replacing worn parts. The process of disassembling tools from different manufacturers is approximately the same, with the exception of some nuances.

Before disassembling the device, the causes of breakdowns are established, which may also depend on the surface of the device. For example, very often there is an unsatisfactory condition of the plastic anther on the cartridge due to its wear.

The reasons for disassembling the puncher can be instability of work, the smell of burning, strange sounds when working with a tool.

This is the reason for the loss of stoppers. In order to prevent the problem, it is necessary to use long drills in the process of working with the tool.

The main prerequisites for the repair of the device and its disassembly may be the following:

Instrument instability.
Occurrence of strange sounds when the device is turned on.
The appearance of a burning smell.
In the absence of visible reasons, the device does not hammer.

When these signs of malfunction are identified, the question arises of the need to repair the device.

How to properly disassemble the rotary hammer gearbox

With great care, the gearbox with the body of the device should be separated in different directions so that a gap of 30 to 50 mm is formed between them. First you need to move the switch to the “hit with drilling” position, only then the switch is removed. After that, remove the housing from the gearbox.

The gearbox is an element that transmits rotation to the cartridge from the electric motor. This is due to bringing the impact mechanism into working condition. The gearbox includes a set of gears that have a different shape. It can be cylindrical, worm or conical.

Disassembly of the perforator gearbox: 1 - special ring, 2 - releasing bushing, 3 - ring, 4 - ball, 5 - spring. Bearing shield from the casing: 22 - closing spring, 29 - ring, 30 - spring, 31 - retainer.

The unit of the device, including the gearbox, has an electronic device that is able to regulate the number of revolutions. It also regulates the beat frequency. This element requires periodic inspection, lubrication and replacement of worn parts. Before disassembling the perforator gearbox, the cartridge is disassembled, then the lever that switches modes should be disconnected. You may need a flat head screwdriver for this.

For example, in order to repair the armature of the gearbox or its stator, three bolts are unscrewed on the back cover of the tool and the cover is removed. The tool must be disconnected from the power supply before starting work. Be sure to pay attention to the condition of the brushes. However, you need to ring the power button and cable.

If a breakdown is detected after ringing, they proceed to inspect the cable, since it should be checked whether there are kinks in it. In the absence of visual damage, each core of the cable is checked by unwinding it. After penetrating inside the gearbox, an inspection of such parts and spare parts should be made, such as:

Gears.
Striker.
Piston.

It is important to pay special attention to the gear teeth. When worn elements are found, they are replaced with new components. If they are absent, then a thorough cleaning is carried out using white spirit or gasoline.

It should be noted that repairing light-class rotary hammers is not as difficult as more serious equipment, which only professionals understand. When choosing a tool of any class, it is better to purchase a model that has a vacuum cleaner. This device allows you to save time, which is spent on cleaning the tool. Since the amount of dust will be the least, the use of the tool will be safer.

Another problem is the breakdown of the windings, which is also associated with the appearance of dust. In this case, the tool is disassembled if thorough cleaning and replacement of all elements that cannot be repaired are required.

How to disassemble a rotary hammer to lubricate it

For prevention, the device must be cleaned every two weeks, impregnating it with varnish or lubricant. The choice of lubricant is made very carefully. Basic rules to remember when lubricating:

You should buy a solution that is produced by the same manufacturer as the perforator itself.
You can use the oil used for a diesel engine, if there is no varnish or special oil.
It is necessary to replace the brushes, which are more likely to wear out.

It is necessary to disassemble the puncher to replace the brushes even if the tool is a fairly expensive model. To replace the brushes, the puncher is disassembled according to the principle described above. After that, they find brushes that are worn out, remove them from the structure, put others in their place.

It is best to use carbon-graphite brushes, which are the best and not too expensive option. Graphite brushes are used, which are distinguished by a long service life. Coal serve for a relatively short time, but they are in contact with other parts of the perforator at a qualitative level.

If you need to repair a puncher, then this means, at a minimum, that you already have it. Although it is quite possible that you are just choosing this impact drilling tool, while studying the weak points of its design, and which nodes theoretically can fail in it.

Well, let's try to help you. In this article we will study:

Perforator device.
The most loaded parts and components of the tool.
Disassembly and assembly.
Measures that extend the life of percussion drilling power tools.

Perforator device

Studying the principle of operation of a percussion drilling tool will not only expand your technical horizons, but, first of all, will allow you to competently carry out its maintenance and, if necessary, repair. To make it easier to understand the processes that occur during drilling in hard materials (and this tool is designed to perform just such jobs), do not be too lazy to watch these two short videos. The first one clearly shows the operation of a rotary hammer with a longitudinal engine.

The second video shows the device of the perforator with a transverse engine.

So, let's start with the most important thing: concrete, brick, stone, the tool destroys shock wave, which occurs at the moment of a very short contact of the striker with the end of the drill (through the striker). The energy of the shock wave is transmitted through the drill (impact drill) and destroys the bonds (forms microcracks) between the grains of the minerals that make up the stone (concrete, brick). The spiral grooves of the rotating drill serve to remove loose particles of material from the hole.

(From this follows the conclusion: there is no need to press hard with a puncher on a concrete wall, it will not drill faster - you will only get tired yourself, and the tool will break faster.)

The striker is made of high-strength steel and moves freely enough inside the piston cylinder.

The sealing rubber ring seals the gap, preventing air from passing freely into the gap between the cylinder and the drummer.

The outer race of the rolling bearing, mounted at an angle on a shaft rotated by an electric motor, reciprocates, causing the piston cylinder to move back and forth.

How to repair a Makita HR 2450 rotary hammer if the shock mode is gone

When the cylinder is moved forward (towards the drill), the drummer remains in place by inertia, the air between the drummer and the rear wall of the cylinder is compressed and pushes the drummer to meet the end of the drill.

In fact, this air serves as a damping element that prevents deformation and destruction of the perforator cylinder. In a tool with a transverse engine, the cylinder is stationary, and the rarefaction and compression of air behind the striker is created by a piston driven by a crank mechanism.

The most loaded parts and assemblies of the perforator

Based on the foregoing, the impact mechanism and gearbox experience maximum loads during long-term operation. Part of the striker's kinetic energy is converted into thermal energy and heats the entire assembly. The sealing ring continuously rubs against the inner surface of the cylinder and wears out with a lack of lubrication, over time passing more and more air from the working area.

The energy of compressed air becomes less and less - the impact drill no longer hammers as it should. When repairing a hammer drill on your own, it is sometimes enough to simply replace the lubricant in the gearbox, piston cylinder and the rubber o-ring on the drummer.

During long continuous operation or during normal drilling under high load, the electric motor can easily overheat and burn out. Although the latest models of the tool have an electronic control unit that includes motor overload protection. If you wish, you can read about troubleshooting the electric motor, power cord, electronics and power button in the previous article.

Disassembly and assembly of the puncher

When trying to repair a puncher with your own hands, first of all, you need to disassemble it. To do this, remove the rubber tip, the annular spring, the casing of the drill fixing clutch. The fixing steel ball is removed. By turning the operating mode switch to its extreme position, pressing the locking button on it, the switch handle is removed.

The rear pad on the handle is removed, the brushes of the electric motor are removed. 4 screws are unscrewed (from the side of the drill) and the entire front part of the tool (gear housing) containing the barrel, gearbox, impact mechanism and operation mode switch will be removed.

The motor rotor is removed. Two screws securing the stator are unscrewed. 4 terminals are removed from the stator contacts, then it is removed from the housing. The switch (button + reverse switch), brush holder, noise filter and power cord are removed.

If it is necessary to repair the puncher in terms of the impact mechanism and gearbox, 4 screws are unscrewed from the end of the gearbox housing, then the outer plastic casing is removed. It is best to do this in an upright position. Then in the inner case all the details will remain in place.

After replacing the defective part, the assembly is carried out in the reverse order. Parts that turned out to be "superfluous" should be wiped dry and taken to a repair shop along with a puncher.

Activities that extend the "life" of the perforator

All activities are as follows:

Read the user manual and operating instructions for the instrument carefully.
Strictly follow the instructions given in the instructions.
Change gear and impact mechanism lubricant regularly. Exactly replace, since there is no point in adding a new lubricant to the used old one - metal dust serves as an excellent abrasive that “eats” everything in its path.
Lubricate the drill shank before work.
Inspect motor brushes regularly and replace as needed.
Clean the outside of the tool every day after finishing work.
Try not to work in clouds of dust - it is harmful not only for the perforator, but also for your lungs. Ventilate the workplace by opening all windows.
Do not climb into what you do not understand at all - entrust the service to a professional, or, if you have already undertaken to repair the puncher with your own hands, then do it slowly, remembering well where you put it.

We wish you success!

The device of the pneumatic percussion mechanism of the perforator:
1 - oscillating bearing, 2 - piston, 3 - ram, 4 - shock rod

The design features of perforators suggest some differences in the location of standard mechanisms. The main nodes are unchanged in any model. This is an electric motor, a reduction gear, an impact complex mechanism, an end working part (cartridge). The basic principle of operation is the conversion of the kinetic energy of the rotational motion of the engine into impact energy due to the oscillatory movements of the axial shaft (impact) of the impact mechanism.

Definitely interested: How to choose the right puncher - we guarantee it will be useful

Mechanical differences in rock drill designs

The engine of most perforators is commutator. Its location can be horizontal and vertical. The first option for placing the engine is used in light low-power vehicles. The second is in medium and heavy vehicles. Lightweight hammer drills are convenient to use for domestic work, drilling small holes, easy operation of old wall or floor coverings. They can also work in hard-to-reach places, however, the vibration of this type of tool, given its percussion mechanism design, is quite large. And their power is hardly enough to work on monolithic concrete.

Vertically mounted rotary hammers are equipped with an anti-vibration system, as well as a crank-and-rod impact mechanism, which is more powerful and resistant to long-term loads. The impact power in some modifications of the heavy type can reach 20J, the average - 8. They are larger in size and weight of the tool, and are designed for especially hard surfaces.

The principle of operation of the percussion mechanism

The rotational movement of the engine drives one of the most important components of the perforator, the percussion mechanism. The pneumatic system of this unit has 2 versions - using a swinging bearing or a crank mechanism combined with a gear part. When the shaft rotates, oscillatory rotations of the piston are created, pumping air into the working cylinder of the system. In this cylinder, due to the small space, compressed air pressure is created, which moves the ram and the striker. As a result of short-term impulse transitions of the piston and ram, these movements are converted into blows.

When idling, being not pressed against a hard surface, this mechanism switches itself off, compression pressure is not formed, and shocks are not produced.

How to properly repair a hammer drill on your own

The working mechanism remains stationary.

Shaft rotation adjustable by pressing a button if soft start is provided. On some models, the button has a trigger limit setting that adjusts the engine RPM and power.

Perforator reducer contributes to the transfer of the number of revolutions with the appropriate parameters of power and torque from the initial node (engine) to the final one (percussion mechanism). Reducing the gear ratio is necessary for the normal operation of the entire apparatus with its vibrational parameters. The lowering type of gearbox leads to fewer engine revolutions and an increase in the power of the final unit. To lubricate it, a specialized dense grease such as grease is used, refilled during manufacture or current repairs.

Perforator body it is made mainly of metal (duralumin alloys, steel), only near the electrical part, in the area of the release button, it is made of durable plastic.

Photo: tool-land.ru

Photo: www.expertcen.ru

Hammer drill not working

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The problem is this: yesterday, while drilling holes of 10 mm, for fixing foam plastic, the puncher stopped working in impact mode (both in impact mode and in drilling + impact mode), having drilled half the depth of the hole, it refused to work further.
In the drilling mode, the hammer drill works. Also, if you switch to drilling mode, you can hear that the motor in the middle is working, but drilling is not working.
Please tell me what could be the reason for this inconvenience. Can you manage on your own? Need to take it in for repairs?
Perforator 4-5 years old, used to build his own house and for work on the farm.

Well, it's hard to say what happened. The most likely version is a breakdown of the mode switching mechanism. Perhaps the contact of such a switch has gone. In any other case, all modes would not work. Take a look, take a look. Perhaps it will cost a simple soldering of the contact.

tyui

Yes, it must be disassembled to look, look at the winding of the piston system.

I once also encountered a similar disaster, I had to change the piston and change the o-ring. In general, it's easier to give it to the workshop.

I'm sorry, as far as I understood, the question was about an electric hammer drill, does an electric hammer drill have a piston and an o-ring?
I agree with Maksimka, the cause of the breakdown is most likely in the switching mechanism, it is possible to repair the puncher yourself.

Dear TS! It is better not to touch the pistons, otherwise the fuel may ignite !!! (Joke, I hope you understand :). tyui, where is the piston in the puncher? Regarding the breakdown: the most reasonable option is to take the tool to a professional repair. If you don’t understand, you can fix something like that, which the specialists won’t fix.

This is the first time I hear about a piston system in a perforator. And to you, Dominic, I advise you to take the hammer for repair if you do not know how to repair the switch. I think that it is not a breakdown in the mechanism itself, but that the contact has moved away or burned out

you need to disassemble the perf gearbox. Yes, see what's wrong. The piston has nothing to do with it if you hear how it works, although it is possible that it cracked.

Do-it-yourself puncher repair

Rather, the reason is in the strike. And, perhaps there are also sealing rings .... depressurization - no pressure is created - the striker does not move.

I stopped hammering Hammer (“barrel”). The lubrication of the striker in the drill holder thickened, became like pitch, and the striker stopped moving in the drill holder. After washing and lubricating the striker and the drill holder with liquid oil, the striker began to move in the drill holder, and the perforator began to hammer.

But if you are passing by, you can still:

Perforator designs

Perforator designs. Portable hammer drills differ little in design from each other. Consider the device of one of the common PP63V punchers (Fig. 16.8).

It consists of a cylinder 1, a barrel 2 and a rear cover 11, interconnected by tie bolts 10 with nuts. Piston-drummer 3 under the action of compressed air flowing alternately into the front or rear relative to the piston cavity of the cylinder performs a reciprocating motion. The sequence of compressed air supply is regulated by the valve air distribution device 15. At the end of the working stroke, the piston-drummer strikes the drill shank with its rod. During the reverse stroke, the piston-drummer with the help of mechanism 9 rotates the drill at a certain angle. To remove destroyed rock from the hole, the perforator has a flushing device 12, which supplies water to the bottom of the hole through the perforator flushing tube, the axial channel in the rod and the holes in the bit.

The drill holder 4 is used for centering the drill in the process of drilling a hole and extracting the drill from the hole. The muffler 16, made of rubber, is mounted above the exhaust holes in the cylinder wall and can be rotated relative to the cylinder, which allows the exhaust air to be directed away from the driller.
To support the perforator during operation, there is a handle 8 connected to the perforator through a vibration damping device 7. It is a tubular metal structure with a spring vibration damping system 5. The puncher is connected to the supporting devices with a bracket 6.
Telescopic perforators (Fig. 16.9) differ from portable ones in the presence of a pneumatic telescopic feeder and a device that protects the mechanisms of the perforator from getting sludge from the hole into them. The telescopic feeder consists of a cylinder 13, a piston 11 with a rod 12. The stop 14 keeps the perforator from turning while drilling and from moving along the surface on which it is installed (soil working, working shelves, etc.).

Do-it-yourself puncher repair: is it real?

The punch has a feed control handle 10 with a button for releasing, if necessary, compressed air from the feeder without stopping the operation of the punch.
The protection of the perforator nodes from ingress of sludge is provided as follows. The drill holder at the perforator is replaced by a grand axle box 3, which is screwed into the rotary axle box 4. The drill rod, made for telescopic perforators without a collar, is held in the perforator in the desired position due to the presence of an additional striker 5. The sludge trap 6 is mounted on the cartridge 7 of the perforator. It catches water, sludge and takes them aside along the sleeve 8. The ingress of flowing sludge into the perforator is prevented by supplying compressed air through a special tube 9 located concentrically to the one through which water enters the hole. The handle 2 of the starting crane, like portable hammer drills, has four positions.

A hammer drill, like any electric tool, requires careful handling, proper operation and timely preventive maintenance. If you neglect these standards, then the device may fail without working out its resource. In case of some malfunctions, a hammer drill can be repaired with your own hands, and to eliminate breakdowns associated with the electrical part of the engine, you will need the help of a specialist.

All malfunctions of the unit can be divided into 2 groups: mechanical and electrical.

Mechanical breakdowns

If any mechanical malfunction appears in the puncher, then its presence can be identify by ear(noise rises, rattle appears).

You may also feel increased vibration or an unpleasant odor coming from the unit body.

So, the following can be attributed to mechanical failures:

breakage of the switch of operating modes of the device;
worn out rubber bands of the drummer and striker;
failure of the impact mechanism;
failure of the unit barrel due to wear;
breakage of gear teeth;
breakage of the chuck, as a result of which the drill flies out.

Electrical faults

Malfunctions associated with the electrical part of the puncher can also be accompanied by an unpleasant odor from the body of the machine, sparking. Also you may notice that the engine heats up quickly and hums without rotating, or smoke comes out of it.

Electrical breakdowns of the device include such as:

the device does not turn on;
breakage of the start button;
brush wear;
collector clogging;
violation of electrical contacts;
burnout of the stator or rotor winding of an electric motor.

Perforator disassembly algorithm

To eliminate mechanical and electrical faults (with the exception of a broken electrical plug), disassembly of the unit housing is indispensable. The most popular among craftsmen, both home and professional, are the brands of rotary hammers Bosch, Makita, Interskol, Energomash. The design of units from different manufacturers is approximately the same, therefore, the methods for disassembling the devices will be similar. But you should not disassemble the device completely, since it will be difficult to assemble it back. The photo below shows what a completely disassembled hammer drill looks like.

Cartridge dismantling

Disassembly of the unit for troubleshooting should be carried out carefully, with the inspection of each removed part. To ensure that the assembly does not cause difficulties, it is better to photograph the disassembly process. If you did not find external defects on the device, then it is recommended to start disassembling it with a cartridge.

We disassemble the case

If disassembly of the unit body is required, the operating mode switch must first be removed.

Dismantling the electrical part of the puncher

To get to the electrical part of the device, if you suspect that it is here that there may be a breakdown, you must perform the following steps.

If you want to disassemble the barrel perforator, with a vertical arrangement of the electric drive, then the handle is first removed, and then the bolts holding the engine are unscrewed.

Motor brush replacement

The main sign that it is time to change the brushes is the formation of increased sparking in the area of the electric motor collector, the rapid heating of the brush holders, and the smell of burning. When the brushes are not worn out, the spark can only be seen under them. Otherwise, the spark is visible around the entire circle of the collector.

The presence of a spark around the collector with worn brushes is a sign of wear on the bearings, a violation of the insulation of the rotor or stator, burnout of the collector plates, burnout of the stator or rotor.

Another sign that the stator has burned out is the presence of sparks under only one electrode. If you have a tester, then they can check stator and rotor: measure the resistance on the rotor and stator in turn. If it is the same on both windings, then everything is in order with the stator. If you notice obvious signs of problems with the rotor or stator in your rotary hammer, you will have to carry the device to a service center for repair. As for the brushes, you can change them yourself.

To get to the place where the brushes are installed, you will need to disassemble the housing in which the motor is installed, or simply remove the back cover. Opening the lid, you will see the brushes fixed in special holders. The photo below shows what these details look like.

The brushes that are installed on the rotary hammer motors are of 3 types.

Graphite- differ in durability, but since they are very hard, their rubbing to the collector is not ideal, which negatively affects the latter.
Coal- easily rub against the collector, providing good contact, but wear out quickly.
Carbon-graphite- ideal option, as they are a mixture of 2 components that complement each other.

It is very important not to wait until the engine sparks, and after that change the brushes. Replacement is needed after they are worn out by 1/3 of the nominal value (8 mm). Even if one brush is worn out less than the other, you still need to change both.

Pay attention to the condition of the spring in the new brushes and the fastening of the contact. If the spring flies off while the engine is running, it will receive significant damage. Also, if the spring is weak, then it will not be able to provide good contact.

Be sure before you change the brushes, you need to clean rotor and stator from residues of graphite or coal dust. You can clean these parts with technical or medical alcohol.

Next, you should fix the electrodes in the holders and grind them to the collector. To do this, place a piece of fine-grained sandpaper on the collector and rotate in different directions to make lapping electrode. Lapping continues until the contact area of the electrode is slightly rounded. This will ensure its better fit to the collector plates and, accordingly, better contact.

Scheme of the device of the percussion mechanism, its malfunctions and repair

The percussion mechanisms of perforators differ in their design, depending on which family the devices belong to. Therefore, the repair of these mechanisms will occur according to different principles.

Barrel punchers

Rotary hammers with a vertical engine usually have an impact block based on a crank mechanism (KShM). Below is a diagram of this type of percussion mechanism.

The following photo shows the apparatus in section, where you can see the location of the KShM.

The impact mechanism of a vertical motor unit may have the following malfunctions. The crank mechanism has a separate bearing that is mounted on the cam of the eccentric wheel, but sometimes it can be located at the base of the crank. In some models of rotary hammers, a plain bearing (instead of a rolling bearing) can be installed in this place, requiring constant lubrication. If it is not there, or it is already outdated, then this node wears out. When repairing, you will have to completely replace the connecting rod and the eccentric barrel.

Another common problem is striker broke. This malfunction can be calculated if you notice that your punch is no longer hitting. To get to the striker, you will need to completely disassemble the barrel of the device. It is done in the following way.

In this case, the striker is whole. But if it is broken, then replace it with a new one. You should also pay attention to the sealing gum and the seals in the barrel body. If they are worn out, they must be replaced.

Pistol type perforators

The device of the percussion mechanism for a pistol-type unit is slightly different from the mechanism of the same purpose installed in a barrel-type apparatus.

Its main difference is that the piston does not move with the help of a connecting rod, but from a swinging (“drunk”) bearing. Therefore, the most common failure of this assembly is the wear of a “drunk” bearing that needs to be replaced.

The next photo shows a destroyed “drunk” bearing, which is the reason that the hammer has stopped hammering.

The oscillating bearing is removed with a flat screwdriver, which you need to pick up the bracket and remove it. After that, the bearing is easily separated from the gearbox housing.

When replacing a failed bearing, you should flush gearbox, since it is in its body that fragments of a broken part may remain.

After cleaning and installing a new bearing, apply a greasy layer of grease to this block.

Also, the reason that the device does not hit can be a broken striker. To get it, you need to remove the retaining ring, which is visible in the hole.

Take a small screwdriver, hook the ring with it, and move it to the right (toward the gear).

Do the same steps on the other side of the part. Next, insert a screwdriver into the hole in the part and push the removed internal parts of the mechanism.

After this action, the retaining ring and the body, in which the broken striker is located, will be easily removed.

If you disassemble this case, you will see the “culprit” of the malfunction, due to which the punch does not hammer.

When assembling the impact mechanism, be sure to generously apply grease to all parts of it.

Other mechanical failures and their elimination

In addition to breakdowns associated with the impact mechanism, other mechanical breakdowns can occur in the puncher.

Mode switch

There are times when the unit's mode switch fails. Basically, this is due to dust clogging this node. To fix the switch, you will need to disconnect it from the housing (see above for how to do this) and clean it from dirt. If you find any breakage of the plastic parts of the switch, then it will have to be replaced.

Helical gears

The reason that the device stopped working normally, namely, it stopped drilling and chiselling, may lie in worn teeth on the rotor shaft.

If this happens, then the teeth will be worn out and at the intermediate helical gear.

This problem occurs when the tool is jammed or the clutch is not working properly. The breakdown is eliminated by replacing the intermediate gear and the engine rotor.

The drill does not hold in the cartridge

The reason that the puncher does not hold the drill lies in the breakdown of the cartridge and the wear of its constituent parts:

deformation of the balls has occurred;
restrictive ring worn out;
the fixing spring has sagged.

You will need to disassemble the cartridge and replace the problematic parts.

Drill stuck in puncher

The reasons that the drill is stuck in the chuck of the machine may be as follows.

Before installing the tool, you did not apply lubricant to its shank. You will need to move the sealing gum of the cartridge and inject WD-40 into the seat of the tool.
Dust got under the balls. Perform the same operation as in the paragraph above.
If you used a regular drill inserted into the adapter in the puncher, then also process it liquidWD-40, wait a couple of minutes, and, lightly tapping the surface of the clamp with a hammer, loosen the snap in different directions. Usually, after these actions, the clamping jaws open and allow the drill to be removed.
The shank of the tool is riveted. You will need to first fill in the WD-40 fluid and try to pull out the drill. If all else fails, then you need to disassemble the cartridge and knock out the snap. You can also use the tips on how to get a tool stuck in the machine from this video.

A household hammer drill is a versatile and useful tool that solves the most difficult tasks of removing and drilling concrete walls and ceilings, drilling stones, pavement, etc. It is used under constant loads, and over time, individual parts of the mechanism or electrics may fail . A quality product is expensive, so some breakdowns can be repaired with your own hands, the main thing is to know the device and the principle of operation of this tool, indispensable in construction.

Features and device of a construction puncher

Regardless of the type of tool, its power and scope, most modern models, including such popular brands as Makita, Bosh, Stihl, Stern, Metabo, Interskol, etc., have a similar design and consist of the main elements: cartridge, impact mechanism, gearbox , engine, power button, mode switch and connecting cord.

Selected versions are equipped with additional features such as anti-vibration system, impact frequency control and drilling depth limiter. Unlike a classic drill, the hammer drill has a reinforced impact option, which allows it to be used to work with complex and durable materials, including concrete, natural stone, brick, etc.

The engine of the device creates a rotational movement, which is converted into a powerful and translational oscillation of the percussion mechanism (drill, blade or chisel) due to the principle of compression between the active pistons of the tool.

Some models, in addition to the basic functions of drilling and the jackhammer mode, can also have a drilling role. Such tools are considered universal, but they are more likely to fail due to a more complex mechanical system.

For drilling work, it is better to use a reliable drill, and use a hammer drill only for its intended purpose. To avoid premature breakdowns of various parts, they also follow the rules for working with this tool and carry out preventive treatment (lubrication and cleaning of its individual elements).

Types and Troubleshooting

All emerging breakdowns of the perforator are usually divided into 2 categories depending on the nature of the damage:

mechanical;
electrical.

The former usually manifest themselves in additional noise, uncharacteristic rattles, increased vibration, etc. The most common mechanical failures include:

failure of the mode switch;
wear of rubber elements and seals on the striker;
damage to the impact mechanism of the tool;
wear of the main barrel during long-term operation;
malfunction of gears and breakage of the cartridge-holder of the drill or blade.

Such problems most often occur when the operating mode of the tool is violated or when it is used for a long time under high loads. Repair of a puncher for each of the above breakdowns can be done with your own hands, but sometimes you still need the help of specialists.

The appearance of electrical faults is understood by the smell of burning from the body of the device, sparking during switching on and operation, rapid overheating of the engine, uncharacteristic "buzz" inside the mechanism, the formation of smoke, etc. In terms of electrics, such frequent breakdowns are distinguished as:

problems with turning on / off the puncher;
brush wear or clogging of the collector on the motor;
weak circuit contact;
problems with the rotor and stator of the engine;
battery failure (on pneumatic models).

The solution to most electrical breakdowns is corrected independently only with electrical knowledge. In other cases, it is better to contact a specialist in this field so as not to permanently damage the working device.

Disassembly of the chuck and tool body for repair

To eliminate one or more of the malfunctions that have arisen, you should know how to properly disassemble and assemble the hammer drill. The main thing is to follow the algorithm of actions and safety precautions and have the necessary tools at hand. If there is a complex process of disassembly and repair, then it is better to photograph each stage, so that later it will be easier to assemble it back.

The dismantling of the cartridge begins with the removal of the rubber boot (1). Then, with a flat screwdriver, carefully pry off the retaining ring (2) and remove a similar plastic part (3). Next, they begin to remove the main washer (4), at this stage it is important not to lose a small metal ball (or several pieces, depending on the model), which is located under the washer. Now the remaining elements are sequentially removed - the spring (6) and the plate (5).

The wear of one of the above parts leads to the fact that the drill gets stuck in the chuck, which is why the normal operation of the tool is impossible. The damaged element should be replaced, and all other components should be thoroughly cleaned, lubricated and reinstalled in reverse order.

To remove and disassemble the main body above the mechanical part of the hammer, it is necessary to remove the operating mode switch. The roller with the sensor is set to the working position "jackhammer" with the corresponding icon in the form of the letter "T". Next, press the button on the right side of the indicator and gently pull it down until it clicks.

Now pry off the switch with a flat screwdriver and pull it towards you. On some types of instrument, it can be screwed to the body with screws that are simply unscrewed.

Disassembly of the housing in case of electrical damage

If everything is in order with the mechanical part of the device, and during operation there are signs that indicate the electrical nature of the breakdown, it is necessary to remove the plastic casing and, if necessary, disassemble the engine and its accompanying parts.

The back cover on almost all models is fastened with screws, after removing the switch, they are unscrewed around the perimeter and carefully, so as not to break the casing elements, remove the plastic case. Now the fastener of the network cable is unscrewed, the next wiring is removed from the fasteners and the start button is removed.

All wires going to the stator are also removed, after which the motor brushes are removed, which are fixed on several bolts. If there is a problem with the rotor in the gearbox, then it is dismantled, after which the bearings damaged in it are changed using a special tool. If necessary, remove the air intake and remove the stator from the casing, gently tapping it with a wooden object.

Do-it-yourself motor brush replacement

The need for new brushes appears in the presence of a characteristic smell of burning from the body of the perforator, strong heating of the engine during operation and sparking in the collector area. In the normal state of this part, a spark sometimes occurs directly under the brushes, but if sparking occurs throughout the commutator area, then the problem lies in the rotor bearings or burnt out plates.

In this situation, it is quite difficult to repair the instrument with your own hands. To detect malfunctions of the stator or rotor, alternately measure the resistance on them using an electrical tester, it must be the same and consistent on both windings. Otherwise, it is better to contact the service center, but they solve the problem with the brushes on their own.

To replace them, remove the back cover and motor mount inside the device. After that, the parts are removed from the holding boxes along with the springs. There are 2 types of brushes in perforators:

Graphite. They are more durable and practical, but due to the hardness of the material they do not fit snugly against the stator, which leads to its wear during long-term operation.
Coal. They wear out faster than the first ones, but have a better fit, which positively affects the performance of the stator.

On more expensive and powerful models of rotary hammers, combined versions of parts are installed, with graphite and coal in equal proportions. Experts recommend inspecting the motor brushes every year of tool operation in order not to wait for their complete wear and sparking of the motor. They are changed when worn 1/3 of the initial volume (8-10 mm).

Pay attention to the condition of the springs that are installed on these parts and on the fastening of the contacts. If the iron flies off during operation, this will lead to serious damage to the engine, and loose contacts reduce the performance of the tool. Before installing new brushes, the main parts of the engine are cleaned of coal or graphite dust and other contaminants with medical alcohol.

The device and repair of the impact mechanism on the "barrel" perforators

Percussion mechanisms are distinguished depending on the type and purpose of a particular hammer drill. Barrel or vertical versions of Bosch or Makita, on which the engine is mounted vertically, for the most part have impact blocks based on a connecting rod mechanism (KShM).

Most often, a special rolling bearing fails, which is installed either at the base of the main connecting rod, or on the cam wheel with an eccentric. On some models, this part is replaced by a sleeve bearing, which must be constantly and generously lubricated.

Another common problem is a broken firing pin. It is evidenced by the weak impact properties of the perforator or their absence at all. To replace this part, you need to disassemble the mechanical barrel of the tool according to the following scheme.

First, the barrel is disconnected from the body of the perforator. To do this, the cartridge is removed according to the technology described above, after which the barrel is tapped on the countertop until the piston comes out of it, and then the body is knocked out with a hammer and the necessary part is removed.

Now remove the retaining ring that holds the piston in position. Next, the bearing itself is removed, from which the metal balls are also removed.

This allows you to get to the raster sleeve, from which the balls are also removed. It is important not to confuse them with those that were in the bearing, they are smaller in diameter. At the final stage, a flat screwdriver is inserted into the sleeve and the broken striker is pushed out of there.

In addition to this detail, the seals and seals in the barrel body are additionally inspected. If they are worn out, they are replaced with new ones.

Repair of the impact mechanism on horizontal type tools

With a horizontal engine (on many models of Bosch, Hitachi, Energomash, etc.), another shock block system is also performed. In it, instead of a connecting rod, an oscillating bearing is installed on the piston, which sets it in motion. It is also a common reason for the failure of the perforator, namely the loss of impact qualities, when the device simply does not hammer as it should.

Remove the worn part with a flat screwdriver, which pry the bracket on the gearbox housing and remove it. After that, the bearing is easily separated from the main body, and the gearbox itself is thoroughly washed, as fragments of the old part may remain inside. And after installing a new bearing, re-lubricate with a dense layer of a suitable material.

If the reason lies in the striker, then to remove it from the barrel, remove the retaining ring with a screwdriver, which is inserted into the hole and shifted towards the gears on both sides. With the same screwdriver, they push through the body and remove the broken striker from it. When reassembling the impact mechanism, be sure to apply a layer of lubricant to all metal parts.

Elimination of other mechanical failures

If a special mode switch fails, which occurs due to clogging with dirt and construction dust, it is removed according to the instructions described above, cleaned and installed back or replaced with a new one if it is broken.

With the loss of drilling properties and long-term operation of the perforator, the gear teeth on the rotor shaft may be worn out. The problem often occurs if the tool is used incorrectly (too heavy loads) or due to a malfunction and interruption in the operation of the clutch.

If the drill, drill or blade simply does not hold in the chuck, it is necessary to disassemble it and replace the ball, restrictive ring or fixing spring. If the drill gets stuck inside the chuck, the reason lies either in insufficient lubrication on the shank (it can be solved by additional injection of WD-40 under the sealing gum), or the holder has been riveted.

In this case, additional lubricant is applied and after some time the drill is pulled out manually, loosening it in different directions. If this does not help, then disassemble the cartridge and mechanically knock out the tooling with a hammer.

To avoid a large number of problems with a puncher, you must follow the rules for its operation:

at the end of all work, be sure to remove all debris, dust and dirt accumulated in the cartridge;
when drilling concrete structures, the frequency of work is observed (every 2-3 cm, the drill is removed from the wall and allowed to cool slightly);
carry out preventive lubrication of external and internal parts of the tool, especially during its long-term operation;
follow the rules for storing the puncher in a plastic packaging box, in a room with low humidity.

Normal operation of a high-quality rotary hammer will avoid technical breakdowns for a long period of time. Buy only models from trusted manufacturers and use the tool strictly for its intended purpose. If you are not sure where and what type of failure your device has, you should not experiment with it. It is better to contact specialists or a service center if it is covered by a factory warranty.