It often happens that it is necessary to repair the perforator. You should know that this can be done with your own hands, if you understand the design.
The hammer drill, compared to a drill, which is equipped with a percussion function, is much more reliable.
Every person who has worked with a hammer drill at least once knows how difficult it is to use this tool. The owner of such an expensive tool wants the device to be of high quality and do its job 100%. It should be understood that it can save from major breakdowns correct use fixtures. It is important to make repairs in a timely manner. The slightest failure should be cause for concern and preparation for repairs.
Failures can be as follows:
- unstable operation of the structure in the main mode;
- the appearance of extraneous sounds in the process of turning on the punch;
- the smell of burning;
- the tool has stopped hammering, although there is no reason for this.
The principle of operation of the perforator
The principle of operation of the rotary hammer is that the electric motor gives a rotational movement to the bearing, which converts this movement into translational-rotational. The tool is designed so that the energy due to the air cushion will be transferred to the piston, which can transfer the impact energy to the drill.
If any of the above problems appear, then this means that the tool will need to be repaired. This process requires attention, determining the exact cause of the malfunction and knowing how to eliminate it. To determine the problem, you need to familiarize yourself with the design of the tool. The main elements of the perforator can be seen.
It should be understood that if the puncher is broken, then the easiest way is to take it for repair to any of the service centers. However, the disadvantage of this method is that it requires a lot of time. If you know how the tool is disassembled, then repair work can be done independently. It will also be possible to save money, since the costs of paying for the services of service centers are excluded.
The disassembly of the perforator is performed as follows:
- The first step is to dismantle the rubber tip, after which the washer and spring. At the end, the ball is removed.
- When the ball is removed, you will need to unscrew the screws that secure the case. After that, you need to disconnect the stator wires.
- The brush holder is removed.
When the punch is disassembled, you will need to clean the case, it does not matter what kind of breakdown has occurred. In some cases, dirt and dust prevent the structure from functioning normally.
Items needed to complete the repair:
- lubricant;
- screwdriver;
- vise;
- spare parts.
The main malfunctions of perforators
If you know the device of the perforator, then you can easily replace the broken part. In most cases, the repair of this tool comes down to replacing elements that are out of order. These include:
- switches;
- anchor;
- brushes;
- gears;
- starter;
- bearings.
Professional device failures can be complex. Some of them can only be handled by highly qualified specialists. Often there are such problems: breakdown of the winding, rewinding of the armature and starter. These faults are caused by dust. Repair consists of cleaning and replacing elements. From time to time it is necessary to carry out prevention - once every 2 weeks it is recommended to clean the device. Special attention it is necessary to pay attention to the choice of lubricant. If such a mixture is not available, then diesel engine oil can be used.
Another cause of failure is brush wear. Replacing them is very simple: you should disassemble the punch according to the scheme described above, find worn brushes and install new ones in their place. You will need to determine exactly which ones are suitable. Brushes can be carbon, graphite or carbon-graphite. Graphite has a long service life, however, due to the hardness of the material, the collector may be damaged. Carbon fixtures have a short service life, but they are distinguished by good contact with other elements of the punch. If Money, which it is possible to allocate for the replacement of brushes, is not very much, it is recommended to use carbon-graphite brushes.
There may be problems with the mechanical parts of the device. Each device is equipped with switching modes that often fail. To fix the problem, you need to disassemble the punch, find the damaged elements and replace them. It is only important to buy parts that match the existing device. The same problem can be with cartridges that are subjected to heavy loads. As preventive measures you can wash the parts with grease to protect them from dust and dirt. If the cartridge is defective, it will need to be replaced.
How to repair a Makita hammer drill?
To determine the cause of the breakdown, you need to disassemble the cartridge. You need to parse it like this:
- First of all, the lever is dismantled.
- Next, the cartridge is disassembled. To do this, take a screwdriver and remove the gasket from the rubber. Then the retaining ring is dismantled.
- After that, all other elements are removed.
Cartridge problems can be as follows:
- The gasket has worn out. If this happens, you need to clean the tool from dust and replace the boot.
- Cover deformation. In this case, the element is replaced.
- The retaining ring is loose. The element should be slightly tightened if possible. If not, then the part must be replaced.
- If the ball is worn out, then you need to install a new part, lubricate it and fix it in the guide washer hole.
- If the ball guide is worn, the level of wear should be determined. If it is small, then it is enough to lubricate the part. If the element is worn out, it must be replaced.
- The conical spring is the most durable element, but it can also wear out from time to time. The part must be positioned with a smaller vertex to the gearbox.
The assembly of the cartridge occurs in the reverse order. Finally, you need to lubricate the end of the drill.
Switch disassembly and repair
The switch may also be broken. To repair it, you need to disassemble the part. This is done in this way:
- The main task is to pull the latch out of the handle. To do this, you need to insert a screwdriver into the groove on the side of the handle, carefully hook first on one wing of the latch, then on the other. Next, the latch is pulled out of the handle. Care should be taken to ensure that the latch does not pop out of the handle. This can happen if the spring is depressed.
- Next, the handle must be moved to the left so that the protrusions on it and the gearbox housing coincide. The switch will release and can then be removed.
- After that, you will need to remove the latch along with the spring.
- Next, the rubber seal is removed, which is located on the switch handle.
- Cleaning of all structural elements is carried out.
To diagnose a breakdown, you need to perform the following steps:
- The most common problem is the failure of the switch rings, as they constantly come into contact with the scrolling elements during operation. The switch must be changed, but if work cannot be interrupted, then you can simply turn the worn part 180 °. It is worth remembering that this is a temporary measure.
- If they have fallen into disrepair seats then the switch needs to be replaced.
- If the rubber seal is deformed and grease flows out of the gearbox, then the elements must be replaced.
- If the process of the fixing element that holds the part in the gearbox housing breaks, then the modes will switch spontaneously from time to time. This part can not be changed if the problem does not interfere with work.
Prevention is the only method that will avoid most problems during the operation of the tool. Most puncher malfunctions can be eliminated on your own, however, if the problem is not related to those described above, then it is recommended to entrust the conduct repair work specialists.
Different models of rotary hammers have design features that distinguish them from each other - depending on the manufacturer, power and functionality of the tool. However, despite these differences, all rotary hammers contain the same components and systems that ensure the performance of their main function. The main components of the perforator include: an electric motor, a gearbox, an impact mechanism and a cartridge. In addition, there are auxiliary systems and mechanisms that expand the capabilities of rotary hammers or make their operation more convenient and safe - an anti-vibration system, a "vario-lock" device (Vario-Lock - a mechanism for fixing the tool in a certain position), a mechanism for limiting the drilling depth, a dust removal system, mechanism for switching operating modes, etc.
Engine location
As motors in perforators, as a rule, collector electric motors are used. The motors are placed in two positions: horizontal and vertical.
The horizontal layout is used, as a rule, in light perforators, the vertical one - in medium and heavy ones. However, there are exceptions. Heavy rotary hammer Metabo KHE 96 with a weight of almost 12 kg has a horizontal engine.
The tool with a horizontal layout is more compact and convenient to work in tight spaces. However, this design is characterized by an increased shock load on the engine and somewhat worse conditions its cooling.
Vertical layout provides Better conditions engine operation (reduction of shock vibration and effective cooling), as well as a wider amplitude of movement of the piston and striker due to the ability to use a crank mechanism with an increased piston stroke instead of a oscillating bearing.
Perforators with vertical arrangement engines are able to endure more intense work than models with a horizontal layout.
Impact mechanism
The most important node of the perforator is the percussion mechanism, which provides the main percussion function of the tool. According to the type of execution, it can be electromechanical and electropneumatic. The latter type is used in the vast majority of models of modern rotary hammers. It allows you to get a significant impact energy of the tool with minimal engine power.There are two main versions of the impact electro-pneumatic mechanism - using a swinging ("drunk") bearing or a crank mechanism. The first option is used for light and, partially, medium punchers, the second - for medium and heavy ones.
The figure below shows a diagram of a light type perforator. Its impact mechanism consists of an oscillating bearing, a piston, a ram and a striker.
Perforator impact mechanism device: 1 - drunken bearing, 2 - piston, 3 - ram, 4 - drummer (striker), 5 - engine gear.
During the operation of the rotary hammer, the rotation from the electric motor is transmitted to the inner sleeve of the oscillating bearing. At the same time, its outer sleeve, together with a perpendicular axis connected to the piston, oscillates. Between the piston and the ram there is an air space, which, thanks to the increased pressure and rarefaction that is alternately created in it, makes the ram repeat the oscillatory movements of the piston, striking the striker. The latter, in turn, strikes the tool in the cartridge. Thus, the energy of the electric motor is transformed into the impact energy of the tool.
The pneumatic percussion mechanism is equipped with a self-shutoff function when idling. At a time when the tool (drill, drill, crown) is not pressed against the surface to be treated, the ram moves forward, opening a hole in the body for air inlet and outlet. As a result, compression and rarefaction are not created in the working air cavity, the percussion mechanism is turned off, and the perforator works without impacts. When the tool is pressed on the surface to be treated, the hole is blocked by a ram, compression occurs in the air cavity, and the impact mechanism begins to function.
In medium and heavy rotary hammers with a vertical engine layout, the piston is driven by a crank mechanism. The increased amplitude of piston movement contributes to a higher impact power, which in heavy perforators can reach 20 J. The impact mechanism works in the same way as described above.
The device of the impact mechanism of the perforator: 1 - crank mechanism, 2 - piston, 3 - ram, 4 - drummer (striker), 5 - nozzle (drill, chisel, etc.).
At the end of the article there is a video demonstrating the operation of the percussion mechanism..
The figure below shows the device of a domestic-made rotary hammer Progress PE-40/1050, with a power of 1050 W, with a vertical engine and a crank drive of the percussion mechanism. The rotation from the engine through the worm shaft is transmitted to the helical gear, on the shaft of which there is a crank that drives the piston.
Anti-vibration system
Hammer drill manufacturers are developing new anti-vibration systems. Vibration protection systems are divided into active and passive. Active anti-vibration systems (often marked AVS) are installed only on powerful models. To dampen vibration, a simple principle is used: usually it is a shock-absorbing device, a counterweight with a spring, which takes on the recoil. True, this system is not able to completely absorb vibration, it only seriously reduces it.
At the end of the article there is a video demonstrating the operation of an active anti-vibration system..
In addition, the handle can also be responsible for damping vibration: from below it is attached to the body with a hinge, and from above through a spring mechanism. A passive anti-vibration system means the usual rubber pads on the case, which also protect against slipping of the hand. However, we must admit that the sense of the overlays is not too great.
Perforator circuit diagram
Exist different ways perforator motor rotation speed control. The speed of rotation of the engine can be adjusted by changing the force of pulling the trigger, and can also be selected on the dial before starting work. If the rotary hammer has a special circuit, the rotation speed will be the same under any load.Frame
The body of the puncher is made of metal (usually aluminum or magnesium alloys) or impact-resistant plastic. Most often, both are combined. The metal case is stronger than the plastic case and dissipates heat well, providing effective cooling of the tool. According to the laws of physics, air heats up during compression, so it is important to ensure the necessary cooling of the percussion mechanism during the operation of the perforator. To do this, part of the air from the fan wheel passes through the percussion mechanism. This prevents excessive heating of the body of the perforator and maintains sufficient viscosity of the lubricant in the mechanism. To exclude burns from heated metal, various plastic linings are used.Safety clutch
Usually rotary hammers are equipped with a safety clutch, which serves to stop the rotation of the cartridge when the tool is jammed in the hole. This condition is fraught with breakage of the nozzle or perforator and injury to the worker due to a sharp jerk of the tool that occurs when the drill stops instantly. The safety coupling protects against overloads and the electric motor of the tool. When the drill stops, the engine armature also stops, which leads to a sharp increase in electric current in his wrap. The coupling that disconnects the punch chuck from the motor shaft prevents the motor from burning out.Two types of clutches are used as safety clutches in perforators: friction and spring-cam. The first consist of disks, normally pressed against each other and transmitting torque. When the tool is jammed, the disks slip relative to each other, disconnecting the motor shaft from the chuck with the nozzle. The friction clutch is used, for example, in Metabo models.
Many firms use safety clutches of the spring-cam type. They consist of two half-couplings having radially located protrusions and cavities (teeth) at the ends, which are combined during normal operation. The clamping of the coupling halves to each other is provided by a spring. The principle of operation of the spring-cam clutch is based on slipping of the coupling halves relative to each other in the event that the moment of resistance begins to exceed the pressing force of the spring. At the same time, a characteristic crack is heard, signaling that the nozzle is jammed.
It is believed that the spring-cam clutch is more reliable than the friction clutch, however, it also has a serious drawback. It lies in the fact that during operation, the tips of the teeth are rolled, which leads to the operation of the clutch even if the nozzle is not jammed, but only there is a lot of resistance. Some craftsmen cope with this problem by placing a washer 3-5 mm thick under the spring, which increases the compression force of the spring and, consequently, the moment of operation of the clutch. However, excessive "rigidity" of the coupling is also undesirable, since it makes the tool jerk too strong when the nozzle is jammed, which can lead to injury to the hands of people working with the puncher.
Perforator reducer
The rotary hammer gearbox transfers rotational motion from the engine to the chuck and drives the impact mechanism of the tool. It consists of a set of cylindrical, bevel and worm gears. Most often, rotary hammer gearboxes have a constant gear ratio. Regulation of the number of revolutions of the cartridge and the frequency of impacts is provided by an electronic regulator. However, models with two-speed gearboxes are also available.The gearbox is lubricated with grease, which is filled into the gearbox during initial assembly and during Maintenance or repair - at those moments when the punch is disassembled.
Video demonstrating the perforator device:
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For drilling holes in various materials, breaking walls, drilling rocks and roads designed rock drill. The tool is used under heavy loads and eventually malfunctions. You can replace a failed puncher with an inexpensive Chinese model. But if you have a branded instrument, then it is a pity to throw it away. In order not to give half the cost of the puncher 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 punchers
Perforators have several classifications. This is due to the different areas of application of the tool.
The number of modes can be from one to three:
drilling. The puncher works in the mode of a drill;
impact drilling. You can make holes in brick and concrete;
jackhammer, that is, a blow without drilling.
Hammer drive types:
Mass classification:
- heavy. Over 5 kg. Over 1200 W. In construction.
lungs. 2–4 kg. Power 400–700 W. Used in everyday life;
medium. About 5 kg. Power 700–1200 W. Professional;
Types of cartridges used in rotary hammers:
SDS+ is installed on light and medium rock drills for work with drills up to 20 mm;
SDS max is used for drills over 20 mm, so they are installed on heavy rock drills with high power.
Classification by engine location:
Perforator device
Regardless of the functions and designs, rotary hammers have similar basic elements.
The device is a simple puncher with a network drive
Network cord.
Power button.
Engine.
Reducer.
The barrel puncher has the same main components.
Barrel puncher device with network drive
The impact mechanism of the perforator can be made in two versions:
The oscillating bearing is also called drunk. This mechanism is used in light and medium perforators.
Impact mechanism with drunken bearing
The crank mechanism is used in heavy rotary hammers.
Crank-and-rod percussion mechanism
How to disassemble a hammer drill
Disassemble the hammer drill sequentially. Look carefully at all the details. Even if you are looking for a problem in one node, you can find damaged parts in other nodes. When disassembling the tool, clean the case from dust and dirty grease.
How to disassemble the cartridge and remove the stuck tooling
Start by disassembling the cartridge so that it does not interfere with the removal of the gearbox housing.
If a drill or other equipment is not pulled out of the cartridge, there are two options for solving this problem:
- clamp the tool in a vise. Slightly shaking the punch, pull it towards you;
- clamp the rotary hammer in a vise through the rubber pads so as not to damage the plastic housing. Clamp the end of the snap with a gas wrench. Tap with a hammer on the wrench in the direction of the tooling axis.
The second option is used in last resort. If after several blows the drill or chisel cannot be pulled out, stop. You may damage the punch. Disassemble the chuck and gearbox. Try to knock out the snap with a punch. After such a procedure, most likely, a replacement of the raster sleeve will be required. To avoid such a problem in the future, lubricate the end of the snap.
How to remove a stuck drill from a 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 position, in others - to the extreme left. Consider the extreme right position.
Analysis of the electrical part of the puncher
Analysis of the mechanical part of the perforator
- Remove the plastic gear case. You will see an aluminum housing with a screwed bearing inserted into it, an intermediate shaft, a raster bushing.
- Thoroughly clean the plastic housing of the gearbox, because pieces from the collapsed bearing remain in it. Take the magnet and go through all the holes to remove all the balls and metal fragments. Clean out the grease completely. Pieces of the plastic separator may remain in it.
- Remove the intermediate shaft from the drunken bearing.
- To dismantle the helical gear, remove the snap ring and bearing with a special puller.
- To dismantle the spur gear, remove the circlip and spring at the other end of the shaft.
- Remove the sleeve from the sleeve.
- Remove the sleeve from aluminum housing.
- There is a striker inside the sleeve. It is pulled out with a bent rigid wire.
How to assemble a perforator
Assembly is carried out in blocks. First, collect small parts into blocks, and then connect them.
- Insert a bearing with a promshaft and a sleeve into the aluminum gearbox housing.
- Put a rubber band on the body. It prevents leakage of lubricant.
- Connect the grid sleeve to the sleeve.
- Lubricate the drunken bearing and gears liberally on the outside.
- Put the plastic gearbox 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 punch body.
- Insert a screwdriver into the hole in the raster sleeve and twist. It should rotate easily. Tighten the housing bolts.
- Put the brushes in place.
- Insert the button and all the wires into the grooves. Make sure nothing is in the way and put on back cover. Screw it on.
- Before installing the switch button with a screwdriver, move the switch bracket in the punch body. So that the pin that is on the switch gets 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.
- Assemble the cartridge in reverse order.
How to assemble a perforator
Punch Diagnostics
Take the multimeter, put it in the dialing 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 connected to one of the contacts, there should be an audible signal. 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 ring them.
- If the contacts on the stator or brushes do not ring, and the buttons and power cord are working, proceed to the diagnostics of the collector and motor windings.
Diagnostics of wires and buttons of a puncher with a multimeter
At the anchor, first inspect the collector and winding. If the wiring is melted, the burnt insulating varnish will leave black marks or a peculiar smell. You can see bent and crumpled coils or conductive particles, such as solder residue. These particles cause a short circuit between the turns. Manifold damage: Raised, worn or burnt plates.
Run diagnostics 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, and zero means a short circuit between the turns. If it shows the presence of a resistance of more than 1.5 ohms, then check the second winding. Both windings should have approximately the same resistance;
check the absence of breakdown to ground, that is, the short circuit of the winding with the metal case of the stator. Set your multimeter to maximum resistance. Connect one probe to the end of the winding, the other probe to the metal case of the stator. The unit indicates the absence of a breakdown.
- does not turn on. Check the electrical circuit;
- perforator does not hit. Breakage in the impact mechanism;
- the tool does not turn, does not drill. Causes: armature bearings, armature gear, gearbox;
- the drill flies out, does not hold. Malfunction of the cartridge or raster sleeve;
- sparking in the electrical housing. Causes: violation of the insulation of the armature winding, wear of the brushes, collector, clogging of the brush holders;
- sparking in the power button area. Faulty button contacts or wires;
- the drill gets hot. The reason is worn brushes, short circuit of the winding turns, poor lubrication of the gearbox;
- puncher does not hold a cartridge. Snap ring or locking washer broken.
- To replace the button, just unscrew the screws of the contacts. But there may be buttons without screws. Here, next to the contacts, there are holes into which a needle or a thin awl is inserted. Poke into the hole, push in and pull out the wire. Do not pull on the wire, you may damage the button.
- Wires must be stripped and tinned.
- Take an old button and buy a similar one.
- On the new button, insert the awl into the hole, press lightly and insert the wire. It will automatically be clamped by contacts.
- 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. Connect the wire from the second brush to the button as well.
set the resistance to 200 ohms. Connect the probes of the device to two adjacent collector plates. If the resistance is the same between all adjacent plates, then the winding is working. If the resistance is less than 1 ohm and very close to zero, there is a short circuit between the turns. If the resistance is two or more times higher than the average, then there is a break in the turns of the winding. Sometimes, during a break, the resistance is so high that the device goes off scale. On an analog multimeter, the arrow will go all the way to the right. And on digital it will not show anything;
mass breakdown determination. Set the maximum resistance on the scale of the device. Depending on the tester, it can be from 2 MΩ to 200 MΩ. Connect one probe to the shaft, and the other to each plate in turn. In the absence of faults, the resistance should be zero;
The anchor can be saved if the balance is not disturbed. If during the operation of the device an intermittent hum is heard and there is a strong vibration, then this is a violation of the balance. This anchor needs to be replaced. And you can repair the winding and collector. 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 machined, extended or soldered. In addition, you should not undertake anchor repair if you are unsure of your capabilities. It is better to replace it or take it to the repair shop.
Checking the performance of the stator with a multimeter:
Malfunctions and their causes
Frequent malfunctions of the perforator:
DIY repair
When disassembling the assembly, carefully inspect the parts for cracks and chips.
Replacing the power button
Before replacing, mark the wiring and button contacts so as not to confuse the connection order.
Replacing a button with an awl
Brushes should be checked periodically. If one is worn by 40%, change both. Also, clean the brush holders.
Replacement and connection of the stator
Bearing replacement
The drill has several bearings. You will need a puller to remove them. In some cases, it is necessary to remove the retaining ring. If there is no puller, they hang the shaft with the bearing and knock it out with a piece of wood. The bearing is seated using a fitting made of a polypropylene tube by tapping on it with a hammer.
Cartridge replacement
Cartridges in rotary hammers are very easy to change. Remove the rubber boot, retaining ring, plastic boot, washer that presses the balls, fixing plates, spring. IN different models the number of rings and plates is different. Replace them with a new set.
Drunk Bearing Repair
Prepare a flathead screwdriver, a clean rag, and the gear lubricant recommended in the manual.
Repair of raster bushing and impact bolt
To disassemble the raster sleeve, you need to compress the spring, remove the retaining ring and gear.
Raster sleeve assembly and without gear
The impact bolt is repaired by replacing parts or replaced completely if it has fallen apart.
Sleeve replacement
The sleeve wears out less often than the raster sleeve, but with frequent overheating of the tool, it also fails. Remove the grid sleeve and sleeve from the aluminum gear case. Put a new one in its place.
Worn and new sleeve with striker
Features of barrel puncher repair
Repair of a barrel puncher has the same principles as a simple one. The main difference is in the design and number of elements.
Replacing the brushes on a barrel puncher
Impact mechanism and gearbox repair
The main difference between a barrel puncher and a gearbox that is simple in design. Some models have an impact mechanism with a drunken bearing.
Barrel puncher with screwed bearing
But most rotary hammers have a crank-and-rod impact mechanism.
Barrel perforator with crank percussion mechanism
All gears and bearings should be checked and lubricated. Worn change. To disassemble this design, you need to unscrew the bolts on the body. The barrel is knocked out of the body rubber mallet. The bearings are removed with a puller.
How to remove the striker and raster sleeve from a barrel puncher
Due to a faulty striker, the puncher stops beating.
Barrel Punch Repair
Proper operation and care of the perforator
In order for the puncher to work for a long time, some recommendations should be followed:
before fixing the snap, lubricate the shank with the agent specified in the instructions;
after work, clean the chuck and tooling;
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;
Take breaks for large workloads to cool down. During breaks, you can clean the cartridge;
spend regularly complete analysis tools for cleaning and lubricating.
If the punch has any malfunction, read the instructions. Inspect the instrument carefully. If you do not doubt yourself, then do the repair yourself.
A hammer drill, like any electric tool, requires careful handling, correct operation and timely prevention. 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;
- breaking chuck, causing the drill to fly out.
Electrical faults
Malfunctions associated with the electrical part of the hammer may also be accompanied by bad smell from the body of the apparatus, sparks. 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 need to disassemble barrel puncher, with a vertical arrangement of the electric drive, 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 at your perforator clear signs problems with the rotor or stator, 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 –perfect 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, put a piece sandpaper fine grit on the collector and rotational movements in different directions, 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
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 is set in motion not with the help of a connecting rod, but from a swinging (“drunk”) bearing. Therefore, the most frequent breakdown of this node is the wear of the “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 is easy to get, and the body in which the broken striker is located.
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 in a puncher conventional drill inserted into the adapter, 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 perforator is such a tool, without which today it is difficult to imagine the bulk of repair and construction work. That is why today every person associated with repair and construction seeks to get this tool for himself. A video about repairing a puncher with your own hands will be of interest to everyone who wants to learn how to identify and fix breakdowns of this tool on their own.
Finding out the cause of the breakdown
In order to know what specifically needs to be repaired, you need to understand the causes of the failure of the puncher. This video will help you do it.
Replacing the bearing in the rotary hammer
In those cases when, during the operation of the punch, you began to hear a rustle that was uncharacteristic of normal operation, or suddenly felt that the drill began to slip, then it was time to change the bearing. See this video for how to do it.
Disassembly of the rotary hammer gearbox
The gearbox in the puncher is necessary to transmit rotational motion from the engine to the cartridge. It is he who activates the percussion mechanism. In order to lubricate the parts or replace them, it is necessary to disassemble the gearbox. See this video for how to do it.
Another video about the disassembly of the gearbox.
Perforator Lubrication
In order for the perforator not to fail, it is necessary to carry out proper care for it. One of the main conditions proper care– regular lubrication of the tool. And in order to lubricate the device, it must be disassembled. You will learn how to do this by watching this video.
