How to properly repair a hammer drill on your own. Do-it-yourself hammer drill repair and operating tips No mains voltage

People who have used a hammer drill at least once are well aware of how difficult it is to use it correctly and monitor its working condition. That is why systematic repair and maintenance of this device is an integral part of the operation process. Repairing a rotary hammer with your own hands is the most financially profitable option, especially since some of the damage is minor.

A hammer drill is an indispensable device in construction. However, if used incorrectly, it can quickly fail.

Such frequent problems with the tool are due to the fact that it is used in very difficult conditions when greater productivity is required. Often, a hammer drill simply cannot withstand the loads that are placed on it. Even branded models are not immune from breakdowns.

As a rule, almost any tool that stops functioning over time can be repaired at home. However, not everyone has an idea of how to repair this or that instrument. The hammer drill is no exception.

Some general information

When a tool fails, it often happens that the cause of the malfunction is some loose wire. Many people pay a lot of money at service centers to insert this wire into place. Mechanical damage can most often be noticed visually. Upon careful inspection of a broken hammer drill, you can, for example, see a minor malfunction that led to a breakdown.

However, there are also situations when the usual “old-fashioned” method - shaking, knocking - cannot solve the problem. In this case, the question arises: contact a professional repair office or undertake the repair yourself.

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Can I repair it myself?

If no damage is visible during a visual inspection of the hammer drill, then the next step is to disassemble it.

It all depends on how serious the breakdown is and whether you have certain skills to fix a broken hammer drill. If we are talking about an old tool that has been in use for a long time and is not of particular value to the user, then you can try and find problems yourself. In addition, if the breakdown is visible visually and you have an idea of what needs to be done with the tool, then independent repair also takes place.

If the hammer drill model is more modern, purchased relatively recently, and costs a lot of money, then it is not always recommended to take on the work yourself, as you can make it even worse. If no visible problems were found during the initial inspection, then further repairs are not recommended. Only users with experience and technical skills should carry out repairs.

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Some signs of possible problems

If during operation you find any malfunctions in the operation of the hammer drill, then you need to find out the cause of the malfunctions.

Of course, when people purchase a hammer drill, they expect 100% performance from it. Especially if the purchased device is a high-quality imported product. Therefore, in order to prevent serious damage, you need to have an understanding of how the device works. Based on the operation of the tool (certain signs), it is sometimes possible to determine the cause of the malfunction. Such things should not be neglected to prevent further damage.

Unpleasant smell from the device, especially burning.
The operation of the rotary hammer in normal mode is unstable - short circuits or short pauses in operation occur.
The device does not perform its intended purpose sometimes or for a certain period of time.
When you turn on or operate the instrument, strange sounds appear that were not present before.

If one of the above or other signs of unstable operation of the hammer drill is noticed, you should immediately find out what is wrong. Attention and care of the instrument are essential long term operation. Therefore, the first step towards it is the ability to completely disassemble it into its component parts.

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How to disassemble a rotary hammer or drill?

In order to repair a rotary hammer, you need to know how to disassemble the device correctly and in what order.

Many may wonder what this is for. The answer is quite simple: if you disassemble the tool into its components and find that one of the parts is broken, you can purchase a new one and replace the spare part. Most may also think that it is much better and faster to take the tool to the appropriate service center, and they will fix it for you. However, first of all, you will need to spend a lot of time bringing and taking the tool, which is extremely wasteful when work is limited; In addition, this is a waste of extra money on repairs. Thus, by carrying out repairs yourself, you can save money and time on repairs.

Disassembly instructions:

You need to start working from the top node. First, the rubber tip is removed, then the washer, and finally the spring and ball.
After removing the ball, you can begin to unscrew the screws that hold the body in place. Next, remove the cover on the handle (if it is available). Only after the work has been done are the starter wires disconnected.
It is necessary to remove the brush holder.
On at this stage you need to separate the gearbox and housing before a gap forms. The switch will be removed through this gap.
At the final stage, the hammer body is placed vertically and fixed in one position using a vice. All parts and spare parts are carefully removed from it.

Regardless of what kind of damage is present, it is strongly recommended to clean both the body and all parts from dust and dirt.

Unremoved contaminants may further interfere with the stable operation of the hammer drill.

A properly working hammer drill is an excellent assistant in the household and in production. This universal tool, which has many functions, allows you to comfortably solve even the most complex tasks. If a hammer drill breaks down, it is not at all necessary to immediately take it in for repairs. Home handyman can disassemble and repair this instrument independently. How to repair a rotary hammer with your own hands?

The device of the hammer drill and its mechanism

Unlike a drill, as well as impact drill, the hammer drill has an enhanced impact function, which puts it an order of magnitude higher in situations where it is necessary to use significant mechanical impact on processed materials.

This is achieved design features hammer drill devices. The device is equipped with an independent mechanism for generating a powerful pneumatic push of the working tool, and this ability frees the master from the use of physical effort when drilling and chiseling concrete and stone.

Impact mechanism of a hammer drill in section

Conversion rotational movement of the electric motor into translational oscillation of the impact mechanism is performed by creating compression between the pistons. This movement is transmitted to the drummer. The striker, made of high-strength steel, in turn, sends the energy of compressed air directly to the working tool - a drill, chisel or shovel. This design of the unit makes it possible to increase the impact power to a huge destructive force - 20 kJ.

Rotary hammer with a vertical engine (“barrel”)

Depending on the location of the engine, drill-type and barrel-type hammer drills are distinguished.

The first type of device is similar to a drill, in which the motor is located in the same axis with the drill.
In rotary hammers of the second type, the motor is installed perpendicular to the drilling axis.

Barrel hammer drills are larger in size, but at the same time have a more advanced cooling system, which allows you to operate the tool for a long time without stopping. Devices in the form of a drill are much more compact; they are convenient when working in cramped circumstances when access to the object is limited.

Diagnostics of rotary hammer faults

If during operation problems in the operation of the hammer drill become obvious, you should disconnect it from the power supply and carry out an external inspection. If external signs no faults were found, you will have to disassemble the case and look for the problem inside.

One of the reasons for device failure is a break in the power cord. In this case, the rotary hammer motor does not turn on. To diagnose it, you need to carefully inspect the cable connecting the tool to the network. It must not be damaged, broken or melted. A working power cord remains cool during operation. If the wire is not in order, it should be replaced with an equivalent one. The cross-section of the conductive elements must correspond to the power consumed by the tool.

Universal diagnostic tool for electrical circuits

Conventionally, all hammer drill malfunctions can be divided into two categories - mechanical and electrical.

Failures in the mechanical part: the crown does not pull out of the barrel, the drill does not chisel, the drill does not rotate, and others

the drill does not chisel;
the drill does not rotate;
the crown cannot be pulled out of the barrel (jammed);
the chisel does not stay in the chuck (it pops out);
extraneous sounds are heard inside the mechanism, grinding, vibration.

Electrical faults: the motor does not rotate, the brushes on the commutator spark and other types of breakdowns

The following signs indicate problems with the electrical part of the hammer drill:

the motor does not rotate when turned on;
the brushes on the commutator spark intensely;
the smell of burnt insulation emanates from the body;
Acrid smoke comes out of the tool during operation.

In order to find out and eliminate the cause of all these phenomena, the hammer drill must be disassembled.

Procedure for disassembling and assembling the device

You should only proceed with disassembly yourself if you have the appropriate tools and equipment. To repair a rotary hammer with your own hands you will need:

screwdrivers with different slots;
vice;
wrenches and socket (hexagonal) keys;
bearing pullers.

In addition, you will need spare parts for replacement, rubber seals and gaskets. To lubricate the gears of the mechanisms you will need:

grease;
rags;
cleaning solvent.

In case of self-repair of the electric motor, in addition to the multimeter, you will need:

spare carbon (or graphite) brushes;
copper wire of the required cross-section;
template for rewinding reels.

Removing the cartridge

Disassembling the hammer drill begins with removing the cartridge. As a rule, this is an SDS-plus system cartridge, which is disassembled using a flat-head screwdriver. In this case, there should be no drill or chisel in the chuck.

There are times when the drill gets jammed and it is not so easy to get it out. Then you need to use a rubber hammer to carefully tap the cartridge around the circumference and pour a few drops of lubricant like WD-40 inside. After a few minutes, try again, the drill should come out easily. After this, you can begin to disassemble the cartridge itself. Procedure:

Pull the plastic skirt down.
Use a screwdriver to remove the rubber protective boot.
Unclench and remove the retaining ring located behind the boot.
Remove the plastic boot, spring, locking plates and balls.
Clean all parts from old grease and store them in a clean place.

Schematic diagram SDS chuck devices

Video: how to remove a drill stuck in a chuck

Removing the mode switch

To remove the operating mode switch, you must:

Move the toggle switch to the “blow” position (icon with a hammer) and turn it about 1 cm lower.
Release the lever from its socket.
Pull the lever towards you.

The switch is removed in the position below the “shock”

How to check the start button and brushes

To get to the commutator brushes and the start control button, you need to remove the back cover. To do this, two or three screws are unscrewed from the plastic case (depending on the model).

If the cause of the malfunction lies in the wear of the brushes, you can eliminate it by installing a new pair. Working length brushes must be at least 8 mm. The rubbing surface is without traces of scale or chips.

Disconnecting the carbon brushes from the commutator

The start button is checked using a multimeter. It must be remembered that the engine speed control system is also located inside the trigger mechanism. If melted plastic is visible on the button body, it should be replaced entirely, since it will no longer function properly.

After replacing the button, you need to put the housing cover back in place, do not forget to tighten the screws securely. Only after this can you check the operation of the hammer drill.

How to disassemble an electric motor

To disassemble the electric motor, it is necessary to disconnect the electric motor housing from the gearbox. They are fastened together with four screws. If you unscrew them, the mechanical part is easily separated from the plastic casing. During disassembly, the motor rotor is removed from the guide sleeve, freeing access to the gearbox. Accordingly, it becomes possible to examine the electrical parts of the engine.

Mounting screws connect the two parts of the housing

The motor consists of a movable rotor and a rigidly fixed stator. The rotor rotates under the action of an electromotive force arising on windings consisting of turns of copper conductor. Inspection of the windings is to determine the integrity of the insulation and the absence of a short circuit between the turns. This is done using a multimeter by successively measuring the resistance on the lamellas. If an interturn short circuit is detected, the armature must be replaced or repaired. It is possible to rewind the stator windings yourself at home using a special template.

Stator, commutator and brushes

The armature, as a rule, is changed entirely, along with the bearings and the air intake plate.

The motor armature (rotor) is replaced entirely

How to disassemble and check the gearbox: how to remove the plastic housing, remove the “drunk bearing” and other elements

In order to determine whether the gearbox is faulty, it must be completely disassembled. To do this, the plastic housing is removed and the gearbox is thoroughly cleaned of old grease. The following are disconnected from the gearbox housing:

floating bearing;
drive gear shaft;
raster sleeve;
sleeve with piston.

Sectional view of a rotary hammer gearbox

The floating bearing, also called a “drunk bearing,” is secured in the aluminum gear housing using a bracket that must be pressed out using a flat-head screwdriver. The released bearing is removed and replaced if necessary. In addition, you should pay attention to the fact that inside the “drunk bearing” there is a needle bearing on which the drive gear rotates. When a hammer drill operates in impact mode, it experiences heavy loads and therefore often fails. A new bearing can be purchased separately or as an assembly with a shaft.

A drunk bearing transmits a shock impulse to the tool

The raster bushing contains an impact bolt, which is secured internally with a metal retaining ring. On the sides of the bushing there are two technological holes through which access to the locking mechanism is provided. After removing the ring fixation, the impact bolt falls freely out of the sleeve. Inside it there is a direct striker made of high-alloy steel.

When repairing or replacing the impact bolt, it is also necessary to replace the rubber sealing bushings, which ensure the tightness of the mechanism. All parts of the striker must be generously lubricated with special lubricant.

In the plastic gear housing at the output of the raster bushing there is another needle bearing, which must be well lubricated.

Video: how to repair a hammer drill and replace the impact bolt

Possible malfunctions, causes of their occurrence and solutions

To repair a rotary hammer with your own hands, you must first determine the external manifestations of malfunctions.

The hammer drill does not hit

If the hammer stops hitting when switching to impact mode, but the drill rotates, it is most likely that the floating bearing is damaged. The solution to the problem is to replace it with a new one.

Second possible reason- malfunction of the impact mechanism. Often, when overloaded in work, the steel striker splits, this leads first to a weakening of the impact, and then to its complete absence. The firing pin needs to be replaced.

The third probable reason is wear or breakdown of the piston group of the hammer drill. The liner and piston should be replaced.

The hammer drill does not spin and does not drill

If the chuck does not rotate when you press the start button in drilling mode, the cause can first be determined by the sound. If the electric motor hums but does not turn the chuck, most likely something is preventing the rotor from rotating inside the gearbox. What happened to the engine will have to be found out by disassembling the mechanical part of the tool.

If the engine does not hum when turned on, it is more likely that the motor has failed. Having opened the lid of the device, it is necessary to determine what exactly led to this phenomenon. This could be an open circuit, a broken start button, or a short circuit in the coil windings. Using the tester, the specific cause is determined and appropriate repairs are made.

The drill does not stay in the chuck and flies out

Incontinence of the hammer drill equipment can occur during long-term use. The drill or chisel inserted into the chuck does not hold and flies out during operation. It is not only impossible to continue chiseling with such a tool, it is also very dangerous - a flying chisel can cause injury.

The reason for equipment incontinence lies in wear or breakage of the cartridge. The cartridge needs to be disassembled and determined what the problem is. Perhaps the balls have become deformed, wear has appeared on the restrictor ring, or the retaining spring has sagged. Usually, after replacing the damaged part, the cartridge begins to function normally again.

Video: why drills fly out of a hammer drill

The brushes sparkle

Sparking brushes is a fairly common phenomenon when working with tools in dusty conditions. As a rule, sparking is a consequence of the deterioration of the material of the brushes themselves. Replacing the latter with new ones will help correct the situation; sparks will no longer fly out.

If not, the reason must be sought in the stator or rotor windings. It is possible that the large amount of dust entering the motor has caused the protective varnish covering the copper conductors to wear away. And this entails a short circuit. The presence of an interturn short circuit is checked using electrical instruments (multimeter).

The resistance between the lamellas is measured with a multimeter

Preventive maintenance of tools: replacement of brushes, lubrication of rotor shaft bearings and additional coverage varnishing the windings on the coils will reduce the likelihood of breakdowns.

In addition, it should be taken into account that dust may adhere to the lubricant of the bearing located next to the commutator. To prevent this, the collector is degreased using a swab soaked in alcohol or solvent.

The hammer drill gets very hot

If the hammer drill becomes excessively hot during operation, this is a clear sign disruption of normal operation of the electric motor. First of all, to prevent overheating, you must observe the operating mode of the device:

take breaks at certain intervals;
After loading, give the tool the opportunity to idle.

If the housing temperature does not decrease, then you need to inspect the electric motor. If you notice a characteristic odor coming from under the tool casing, you must immediately stop working and disconnect the device from the network. You can disassemble it only after it has completely cooled down.

The hammer drill does not hold the chuck

Sometimes there is a situation when the cartridge flies off along with the equipment while the hammer drill is running. This occurs due to wear of the chuck body mount at the end of the raster sleeve, which is a retaining ring. If it breaks, the fixation is broken and during the push the rubber boot flies off, followed by the spring and balls.

You can restore normal operation of the cartridge by installing a new locking ring. This is done quickly and does not require any additional equipment other than a regular screwdriver.

Replacing the main components of a rotary hammer

It is best to replace key elements before the part becomes unusable. This will protect the instrument from more severe damage, which would be more expensive and time-consuming to correct. The most common replacements are:

bearings;
start buttons;
brushes;
cartridge.

How to change bearings

If, during a routine inspection, grease leaks are noticeable on the bearing, it crackles or crunches when turned by hand, this means that it is time to replace it. The bearing is dismantled using a special puller consisting of a screw part and a device for gripping the bearing sleeve housing. Tightening the thread creates a force that removes the bearing from the shaft.

The puller is driven by rotation of the threaded rod

Installing a new bearing on workplace produced with rubber or wooden hammer. During installation, it is important to prevent misalignment of the bearing axis relative to the shaft axis. Lubricant is applied to the part after installation.

How the start button changes

To replace the start button, you need to remove the cover covering the electrical equipment of the hammer drill. Then you should disconnect the contacts of the conductors connected to it and pull out the button body from seat. Install a new button in this place, connect the contacts and assemble everything into reverse order.

The button turns on the motor and regulates its speed

How to remove and change brushes

Replacement of the commutator carbon brushes is carried out with an electrical screwdriver. If you unscrew the cover, you will have access to the brushes. Each part is removed one by one from the brush holder sockets. Some models differ in the design of the clamping mechanism; as a rule, it is a spiral spring, which must be removed during replacement.

The procedure for replacing the cartridge is clear from the procedure for disassembling the hammer described above.

Features in the repair of a barrel perforator

All described procedures for assembling and disassembling hammer drill mechanisms are also valid for the barrel variety. However, there are several nuances that must be taken into account when repairing it. The vertical position of the engine at right angles to the impact mechanism somewhat changes the disassembly order. Thus, to gain access to the gearbox and piston, it is necessary to remove the plastic cover located in the upper part of the tool casing. This makes it easier to repair the mechanical part of the device if the shock function suddenly disappears.

Access to the electrical part of such a hammer drill is achieved after removing the lower casing. And replacing the brushes is simplified, since there are holes on the sides of the glass through which they can be easily removed.

It should be noted that many professional barrel hammers do not have a drilling mode. Since their purpose is primarily for drilling and chiseling heavy concrete surfaces, they are equipped with an SDS-max chuck with an 18 mm shank. Fundamental difference The device does not have an SDS-plus cartridge, but the dimensions are noticeably different. L-shaped hammer drills are recognized as more reliable in operation and belong to the rank of professional tools.

Video: how to repair a rotary hammer with a vertical engine

Daily care and storage of a rotary hammer

In order for the tool to serve for a long time and properly, you need to follow simple rules.

Before starting work, conduct a quick inspection of the technical condition of the tool. Under no circumstances should you ignore signs of malfunction if any are found.
At the end of work, clean the rotary hammer from dust and debris. It is advisable to blow with a stream of air from a vacuum cleaner.
When transporting in the cold season, before starting work, give the device at least 20 minutes to “acclimatize” the device. The grease should thaw and become elastic.
Work in compliance with the operating standards described in technical passport tool.

The hammer drill should be stored in a dry and warm place. For long-term preservation, it is recommended to pack it in a plastic bag and cardboard box. Do not allow moisture to come into contact with electrical parts, including condensation from the air.

A case is the best place to store a hammer drill

Aware means armed. Knowing the intricacies of the hammer drill mechanism, you can repair the tool yourself and in the shortest possible time. However, if you look under the casing of the hammer drill in a timely manner, clean and lubricate the mechanisms, then it is quite possible that you will not have to resort to repairs at all. Regular maintenance the device will help extend its service life.

If you need a rotary hammer repair, this means, at a minimum, that you already have one. Although it is quite possible that you are still just studying, at the same time, the weak points of its design, and which components could theoretically fail in it.

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

Device of perforators.
The most loaded parts and components of the tool.
Disassembly and assembly.
Measures to extend the life of impact drilling power tools.

Device of rotary hammers

Studying the operating principle of impact drilling tools will not only expand your technical horizons, but first of all, it will allow you to competently carry out its maintenance and, if necessary, repairs. To make it easier to understand the processes that occur during drilling hard materials (and this tool is designed to perform just such work), take the time to watch these two short videos. The first clearly shows the operation of a rotary hammer with a longitudinal engine.

The second video demonstrates the design of a rotary hammer with a transverse engine.

So, let's start with the most important thing: the tool destroys concrete, brick, stone shock wave, which occurs at the moment of very short contact of the striker with the end of the drill (through the striker). The energy of the shock wave is transmitted through a drill (impact drill) and destroys the bonds (forms microcracks) between the grains of 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.

(The conclusion follows: there is no need to press hard with a hammer drill on concrete wall, he won’t drill faster - you’ll just get tired, and the tool will break faster.)

The hammer is made of high-strength steel and moves quite freely inside the piston cylinder. The rubber O-ring seals the gap, preventing air from freely passing into the gap between the cylinder and the firing pin.

The outer race of the rolling bearing, mounted at an angle on the shaft rotated by the electric motor, performs reciprocating movements, causing the piston cylinder to move back and forth. When the cylinder moves forward (towards the drill), the hammer remains in place by inertia, the air between the hammer and the rear wall of the cylinder is compressed and pushes the hammer to meet the end of the drill.

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

The most loaded parts and components of a hammer drill

Based on the foregoing, the impact mechanism and gearbox are in the process of long work experiences maximum loads. Part of the kinetic energy of the striker goes into thermal energy, and heats the entire assembly. The O-ring continuously rubs against inner surface the cylinder and with a lack of lubrication wears out, leaking more and more air from the working area over time.

The energy of compressed air is becoming less and less - the impact drill no longer chisels as needed. At self-repair For a hammer drill, sometimes it’s enough just to replace the lubricant in the gearbox, the piston cylinder and the rubber sealing ring on the hammer.

During prolonged 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 the power cord, electronics and power button in the previous article.

Disassembling and assembling a hammer drill

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

The rear cover on the handle is removed, and the motor brushes are removed. Unscrew 4 screws (from the drill side) and remove the entire front part of the tool (gearbox housing), containing the barrel, gearbox, impact mechanism and operating mode switch.

The engine rotor is removed. Unscrew the two screws securing the stator. 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 hammer drill in terms of the impact mechanism and gearbox, unscrew 4 screws from the end of the gearbox housing, then remove the outer plastic casing. It is better to do this in a vertical position. Then in the inner case all the parts will remain in their places.

After replacing the faulty part, assembly is carried out in the reverse order. Parts that turn out to be “extra” should be wiped dry and taken to a repair shop along with the hammer drill.

Activities to extend the “life” of a rotary hammer

All activities boil down to the following:

Please read the user manual and operating instructions for the instrument carefully.
Strictly follow the instructions specified in the instructions.
Regularly replace the lubricant of the gearbox and impact mechanism. Exactly replace, since there is no point in adding new lubricant to the used old one - metal dust serves as an excellent abrasive, “eating” everything in its path.
Before work, lubricate the drill shank.
Inspect motor brushes regularly and replace as necessary.
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 hammer drill, but also for your lungs. Ventilate your work area by opening all windows.
Don’t go into something you understand absolutely nothing about - entrust the maintenance to a professional, or, if you’ve already decided to repair the rotary hammer yourself, then do it slowly, remembering well where you put it.

We wish you success!

For drilling holes in various materials, breaking walls, drilling rocks and roads, a hammer drill is designed. The tool is used under heavy loads and malfunctions occur over time. You can replace a failed rotary hammer with an inexpensive Chinese model. But if you have a branded instrument, then it’s a shame to throw it away. In order not to pay half the cost of a hammer drill for troubleshooting, you can do it yourself. No repair is complete without studying the structure of the tool and the procedure for disassembling it.

Types of rotary hammers

Rotary hammers have several classifications. This is due various areas application of the tool.

The number of modes can be from one to three:

drilling The hammer drill operates in drill mode;

hammer drilling. You can make holes in brick and concrete;

jackhammer, that is, impact without drilling.

Types of hammer drill drives:

Classification by weight:

lungs. 2–4 kg. Power 400–700 W. Used in everyday life;

average. About 5 kg. Power 700–1200 W. Professional;

heavy. More than 5 kg. Over 1200 W. In construction.

Types of cartridges used in hammer drills:

SDS+ is installed on light and medium hammer drills for working with drills up to 20 mm;

SDS max is used for drills larger than 20 mm, therefore they are installed on heavy rotary hammers with high power.

Classification by engine location:

Perforator device

Regardless of function and design, rotary hammers have similar basic elements.

The device of a simple hammer drill with a network drive

Power cord.

Power button.

Engine.

Gearbox.

A barrel perforator has the same main components.

Device of a barrel perforator with a network drive

The impact mechanism of the hammer drill can be made in two versions:

A swinging bearing is also called a drunk bearing. This mechanism is used in light and medium hammer drills.

Impact mechanism with drunk bearing

The crank mechanism is used in heavy hammer drills.

Crank impact mechanism of a hammer drill

How to disassemble a hammer drill

Disassemble the hammer drill sequentially. Inspect all details carefully. Even if you are looking for a problem in one unit, you may find damaged parts in other units. When disassembling the tool, the body should be cleaned of dust and dirty grease.

How to disassemble a cartridge and remove stuck equipment

Start by disassembling the cartridge so that it does not interfere with the removal of the gearbox housing.

If a drill or other equipment cannot be pulled out of the chuck, there are two options for solving this problem:

Clamp the tool in a vice. Slightly shake the hammer drill and pull it towards you;
clamp the hammer drill into a vice through rubber gaskets so as not to damage the plastic case. Clamp the end of the equipment with a gas wrench. Tap the key with a hammer in the direction of the axis of the tool.

The second option is used as a last resort. If after several blows the drill or chisel cannot be pulled out, stop. You may damage the hammer drill. Disassemble the cartridge and gearbox. Try to knock out the equipment with a drift. After this procedure, the raster sleeve will most likely need to be replaced. To avoid this problem in the future, lubricate the end of the equipment.

How to remove a stuck drill bit from a hammer drill chuck

How to remove the mode switch

In some models of rotary hammers, the switch is removed by turning it to the extreme right, in others - to the extreme left. Consider the extreme right position.

Disassembly of the electrical part of the hammer drill

Analysis of the mechanical part of the hammer drill

Remove the plastic gear housing. You will see an aluminum housing with a fixed bearing, an intermediate shaft, and a raster bushing inserted into it.
Carefully clean the plastic housing of the gearbox, because pieces from the collapsed bearing remain in it. Take a magnet and go through all the holes to remove all the balls and metal shards. Clean out the grease completely. There may be pieces of plastic separator left in it.
Remove the intermediate shaft from the worn bearing.
To remove the helical gear, remove the retaining ring and bearing using a special puller.
To dismantle the spur gear, you need to remove the retaining ring and spring at the other end of the shaft.
Remove the bushing from the sleeve.
Remove the sleeve from aluminum body.
There is a firing pin inside the cartridge case. It is pulled out with a bent rigid wire.

How to assemble a hammer drill

Assembly is carried out in blocks. First, collect small parts into blocks, and then connect them.

Insert a bearing with a groove and a sleeve into the aluminum gear housing.
Place a rubber band on the body. It prevents lubricant from leaking out.
Connect the raster sleeve to the sleeve.
Liberally lubricate the outside of the bearing and gears.
Place the plastic gear housing on the assembled unit.
Insert the rotor into the gearbox.
Install the stator and air intake into the electrical housing. Connect the two halves of the hammer drill body.
Insert a screwdriver into the hole in the raster sleeve and twist. It should rotate easily. Screw the housing bolts.
Put the brushes back in place.
Insert the button and all wires into the grooves. Make sure there is nothing in the way and put the back cover back on. Screw it on.
Before installing the switch button, use a screwdriver to move the switch bracket in the hammer housing. So that the pin that is on the switch fits between the two metal guides of the bracket.
Place the mode switch just below the impact, push it down and turn it up until it clicks.
Reassemble the cartridge in reverse order.

How to assemble a hammer drill

Hammer diagnostics

Take a multimeter, put it in dial mode and start testing with the power cord.

Connect one probe to the end of the plug, the other to the contacts on the other end of the wire. When connecting to one of the contacts there must be beep. Do the same with the other end of the fork.
Check the power button on the contacts with the power cord and with the stator. Press the button trigger.
Check reverse contacts.
Connect the probes to the brushes to check the contact through the armature.
Connect the probes to the stator wires and test them.
If the contacts of the stator or brushes do not ring, and the buttons and power cord are working, proceed to diagnosing the commutator and motor windings.

Diagnostics of wires and buttons of a rotary hammer with a multimeter

At the armature, first inspect the commutator and winding. If the wiring is melted, the burnt insulating varnish will leave black marks or a specific smell. You may see bent or crumpled coils or conductive particles, such as solder residue. These particles cause short circuits between turns. Commutator damage: raised, worn or burnt plates.

Carry out diagnostics with a multimeter:

The anchor can be saved if the balance is not disturbed. If during operation of the device you hear an intermittent hum and there is strong vibration, then this is an imbalance. This anchor must be replaced. And the winding and commutator can be repaired. Small short circuits are eliminated. If a significant part of the winding is damaged, it can be rewound. Worn and badly damaged lamellas should be sharpened, extended or soldered. In addition, you should not undertake anchor repairs if you are unsure of your capabilities. It is better to replace it or take it to a workshop for repairs.

Checking the performance of the stator with a multimeter:

set the resistance mode to 200 ohms. Connect the probes of the device to the ends of one winding. One means an open circuit, and zero means a short circuit between the turns. If it shows resistance of more than 1.5 ohms, then check the second winding. Both windings should have approximately the same resistance;

check that there is no breakdown to ground, that is, the winding is shorted to metal body stator. Set the multimeter to maximum resistance mode. Connect one probe to the end of the winding, the other probe to the metal stator housing. A unit indicates the absence of a breakdown.

Malfunctions and their causes

Frequent hammer drill malfunctions:

does not turn on. Check the electrical circuit;
The hammer drill doesn't hit. Damage to the impact mechanism;
The tool does not turn or drill. Reasons: armature bearings, armature gear, gearbox;
the drill flies out and doesn't stay in place. Faulty cartridge or raster bushing;
sparking in the electrical housing. Reasons: violation of armature winding insulation, wear of brushes, commutator, clogging of brush holders;
sparking in the area of the power button. Malfunction of button contacts or wires;
The hammer drill is heating up. The reason is worn brushes, short circuit winding turns, poor gearbox lubrication;
The hammer drill does not hold the chuck. The retaining ring or retaining washer is broken.

DIY repair

When disassembling the unit, carefully inspect the parts for cracks and chips.

Replacing the power button

Before replacing, mark the wires and contacts of the button so as not to confuse the connection order.

To replace the button, just unscrew the contact screws. But there may be buttons without screws. Here, next to the contacts, there are holes into which a needle or thin awl is inserted. Poke into the hole, push and pull out the wire. Do not pull the wire, you may damage the button.
The wires must be stripped and tinned.
Take the old button and buy a similar one.
On the new button, insert the awl into the hole, apply light pressure and insert the wire. It will automatically be clamped by the contacts.

Replacing a button using an awl

Brushes must be checked periodically. If one wears 40%, replace both. Also, clean the brush holders.

Replacing and connecting the stator

Remove the stator from the electrical housing. Put a new one in its place.
Screw in the mounting bolts.
Install the air intake.
Proceed to connect the windings. Connect the two ends of different windings to each other and connect to the nearest brush. Connect the other two connected ends to the start button. Also connect the wire from the second brush to the button.

Replacing bearings

There are several bearings in a hammer drill. To dismantle them you will need a puller. In some cases it is necessary to remove the retaining ring. If there is no puller, hang the shaft with the bearing and knock it out with a piece of wood. The bearing is seated using a polypropylene tube adapter by tapping it with a hammer.

Replacing the cartridge

The cartridges in rotary hammers are very easy to change. Remove the rubber boot, retaining ring, plastic boot, washer pressing the balls, fixing plates, spring. The number of rings and plates differs in different models. Put a new set in their place.

Drunk bearing repair

Prepare a flathead screwdriver, a clean rag and the gearbox lubricant recommended in the instructions.

Repair of raster bushing and impact bolt

To disassemble the raster bushing, you need to compress the spring, remove the retaining ring and gear.

Raster bushing assembled and without gear

The impact bolt is repaired by replacing parts or replaced completely if it has fallen apart.

Replacing the sleeve

The sleeve wears out less frequently than the raster sleeve, but if the tool frequently overheats, it also fails. Remove the raster bushing and sleeve from the aluminum gear housing. Put a new one in its place.

Worn and new cartridge case with striker

Features of barrel perforator repair

Repairing a barrel perforator has the same principles as a simple one. The main difference is in the design and number of elements.

Replacing brushes on a barrel perforator

Impact mechanism and gearbox repair

The main difference between a barrel perforator and a gearbox that is simple in design. Some models have an impact mechanism with a screw bearing.

Barrel perforator with a drunken bearing

But most rotary hammers have a crank impact mechanism.

Barrel hammer drill with crank impact mechanism

All gears and bearings must be inspected and lubricated. Change worn ones. To disassemble such a structure, you need to unscrew the bolts on the body. The barrel is knocked out of the body with a rubber hammer. The bearings are removed with a puller.

How to remove the firing pin and raster bushing from a barrel perforator

Due to a faulty striker, the hammer stops hitting.

Drum perforator repair

Proper operation and care of the hammer drill

To ensure that the hammer drill works for a long time, you should follow some recommendations:

Before fastening the equipment, lubricate the shank with the product specified in the instructions;

after work, clean the chuck and equipment;

when working with concrete, remove the drill every 2 cm;

if you need to drill big hole, use drills of different diameters so as not to drill with the largest drill at once;

When doing a large amount of work, take breaks to allow the equipment to cool down. During breaks, you can clean the cartridge;

Regularly carry out a complete disassembly of the tool for cleaning and lubrication.

If the hammer drill has any malfunction, read the instructions. Inspect the instrument carefully. If you don’t doubt yourself, then do the repairs yourself.

Anyone who has ever had to work with a hammer drill knows how difficult the operating conditions are. This is why do-it-yourself hammer drill repair is such a popular request on the Internet. And today we will tell you absolutely everything that concerns the repair of this instrument.

What do you need to know about rotary hammer repair?

Undoubtedly, owners of such expensive equipment want their devices to be of high quality and to do 100% of their job. First of all, it will protect you from serious damage correct use instrument, which we will talk about a little later. And, of course, timely repair of the device. At the same time, any small failure should already be a cause for concern and preparation for repair.

So, such “beacons” can become:

Unstable operation of the hammer drill in operating mode;
The appearance of strange sounds when turning on the hammer drill;
Burning smell;
The hammer drill does not chisel, although visible reasons for this purpose no.

As soon as something like this happens to your equipment, it’s time for repairs. Like any similar work, it requires care, understanding the cause of the breakdown and knowledge of how to deal with it. And your very first step in repairing is to disassemble the tool into its components. For many, even this stage causes difficulties, and therefore it is necessary to know everything down to the nuances - how, what and why!

We disassemble the hammer drill step by step - quickly find a breakdown

Just imagine that your tool suddenly stopped working or you urgently needed to replace a faulty part. The easiest way is to take it to a repair shop service center, however, this takes time, which means it will stall your work for some period. But if you know how to disassemble the device, it will be much easier for you to carry out the rest of the work. In addition, this will lead to significant cost savings, because you will not need to spend money on paying for the services of repair centers.

Instructions for disassembling the tool:

We begin work, starting from the top unit: first, the rubber tip is removed, then the washer, spring, and the ball completes the work.
After you have removed the ball, unscrew the screws that hold the housing, remove the cover on the handle, if available, and lastly, disconnect the stator wires.
Remove the brush holder.
The next stage is to separate the gearbox and housing until a gap forms. It is through this that we will remove the switch.
After this, the body of the hammer drill is placed vertically, fixed with a vice, and all its parts are carefully removed from the device.

Whatever breakdown awaits you, clean the case - sometimes it is dirt and dust that prevent the device from working properly.

Repairing a rotary hammer yourself step by step

You should be as prepared as possible for repairing a device such as a hammer drill, which will allow you to keep financial and labor costs to a minimum. It’s not bad if you are more or less familiar with the design of the hammer drill, you know what parts and assemblies it consists of, which will allow you to quickly replace a broken part. Most often, hammer drill repair comes down to a banal replacement of “flying” elements, which include:

Anchor;
Brushes;
Gears;
Starters;
Bearings;
Cables for connecting to the network;
Switches.

It is worth noting that it is easiest to repair light class tools, taking into account the fact that such a hammer drill is perfect for carrying out construction work at home. But breakdowns of more serious equipment can be much more complex, and only professional technicians can handle them. In any case, no matter what class of tool you are interested in, find a model with a vacuum cleaner - this device will allow you to save time on cleaning, and will also make your work safer, since it reduces the amount of dust.

Another problem is breakdown of the windings, rewinding of the armature and starter, which also arise due to dust. Repair consists of thorough cleaning and replacement of those parts that cannot be repaired. However, “prevention” is more reliable method. To do this, you need to clean the device once every two weeks, saturate it with varnish or lubricant. By the way, you need to be careful when choosing a lubricant. So, there are several rules. First, it is better to purchase a solution from the same manufacturer ( Bosch, Makita, Anchor) as the hammer drill itself, in in this case the composition of oil or varnish will be ideal. If you don’t have such a composition on hand, diesel engine oil is perfect for you.

The second most popular cause of breakdown is brush wear, and it doesn’t matter how much your tool cost - even the most expensive models are susceptible to this problem. Replacing them is very easy: we disassemble the hammer drill according to the scheme described above, find the worn brushes and put new ones in their place. You just need to correctly determine which of them is best to use: carbon, graphite or carbon-graphite. Thus, graphite ones have a long service life, however, due to the hardness of the material, the collector may suffer. Carbon elements have a short service life, but have high-quality contact with other parts of the hammer drill. Purchasing the third option is considered optimal and inexpensive.

There are also problems with mechanical elements devices. Each model is equipped with switching modes, and they often fail, especially on cheap devices. The algorithm of work is the same - we disassemble the hammer drill, find the broken parts, and replace them. The main thing is to purchase elements that are suitable for this model. A similar problem often plagues cartridges that are subjected to maximum load. First of all, protect them from dust and dirt by washing the elements with grease. But if the cartridge does break, we have no choice but to change it.

Now you know how to repair a rotary hammer and see that most of the breakdowns come down to simple cleaning or replacing faulty parts. But if you disassemble the tool and there are no visible reasons, it is better to take the device to a service center - specialists will quickly find the cause and eliminate it.

Operating rules or how to protect the device from damage?

Prevention is here effective method, which will avoid many breakdowns in the operation of the device. In this case, it implies proper use. You should start with how to insert drills correctly: firmly grasp the chuck and pull the spindle axes. When the hole widens, you can install the drill by lowering the chuck. If you are going to work in impact mode, be sure to lubricate the shanks with a lubricant, choosing it according to the manufacturer, but there is also a universal solution from the company Litol, who also deserved a lot positive feedback from users.

To prevent drills from breaking, remember a few rules for working with materials. For example, you cannot use the shock mode if you are working with metal or wooden products.

To protect yourself and maintain safety when drilling concrete, use a safety coupling. And all due to the fact that in concrete structures there may be reinforcement - the drill will simply get stuck in it. If there is no clutch, use low speeds, and do not hold the handle very tightly - if the tool suddenly gets stuck in the fittings, you must quickly release it from your hands, otherwise bruises and contusions cannot be avoided.