Do-it-yourself puncher tempo repair

In detail: do-it-yourself puncher tempo repair from a real master for the site my.housecope.com.

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

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

Perforators device.
The most loaded parts and assemblies of the tool.
Disassembly and assembly.
Measures to prolong the life of the hammer drill power tool.

Rotary hammer device

Studying the principle of operation of a percussion drilling tool will not only broaden your technical horizons, but first of all will allow you to competently carry out its maintenance and, if necessary, repair. To make it easier to understand the processes occurring during drilling in hard materials (and this tool is designed to do just such work), do not be too lazy 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 motor.

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

Video (click to play).

(Hence the conclusion: there is no need to press hard with a perforator on a concrete wall, it will not drill faster - only you will get tired yourself, and the tool will break faster.) The striker is made of high-strength steel and moves freely enough inside the piston cylinder. A rubber sealing ring seals the gap, preventing air from passing freely into the gap between the cylinder and the hammer.The outer race of a rolling bearing, set at an angle on a shaft rotated by an electric motor, reciprocates, forcing the piston cylinder to move back and forth. When the cylinder is moved forward (towards the drill), the striker remains in place by inertia, the air between the striker and the rear wall of the cylinder is compressed and pushes the striker towards the end of the drill.In fact, this air serves as a damping element that prevents deformation and destruction of the cylinder of the rock drill. In a tool with a transverse engine, the cylinder is stationary, and the vacuum and compression of air behind the striker is created by a piston driven by a crank mechanism.The most loaded parts and assemblies of the hammer drillBased on the foregoing, the impact mechanism and gearbox experience maximum loads during long-term operation. Part of the kinetic energy of the striker is converted into thermal energy, and heats up the entire assembly. The O-ring constantly rubs against the inner surface of the cylinder and, if there is a lack of lubrication, wears out, over time allowing more and more air to pass from the working area.The energy of the compressed air becomes less and less - the hammer drill no longer chisels as needed. When self-repairing a perforator, sometimes it is enough to simply replace the lubricant in the gearbox, piston cylinder and the rubber sealing ring on the drummer.During prolonged continuous operation or at the time of normal drilling under a high load, the electric motor can easily overheat and burn out. Although the latest models of the tool have an electronic control unit that includes motor overload protection. If you wish, you can read about troubleshooting the electric motor, power cord, electronics and power button in the previous article.Disassembly and assembly of the rotary hammerWhen trying to repair a hammer drill with your own hands, first of all, you need to disassemble it. To do this, remove the rubber tip, the annular spring, the casing of the drill fixing clutch. The retaining steel ball is removed. By turning the operating mode switch to the extreme position, pressing the fixing button on it, the switch handle is removed.The rear handle pad is removed, the electric motor brushes are removed. 4 screws are unscrewed (from the side of the drill) and the entire front part of the tool (gearbox housing) is removed, containing the barrel, gearbox, percussion mechanism and operating mode switch.The rotor of the engine is removed. The two screws securing the stator are unscrewed. 4 terminals are removed from the stator contacts, then it is removed from the case. Removable switch (button + reverse switch), brush holder, noise filter and power cord.If it is necessary to repair the perforator in the part of the percussion mechanism and the gearbox, 4 screws are unscrewed from the end of the gearbox housing, then the outer plastic casing is removed. It is better to do this in an upright position. Then, in the inner case, all parts will remain in place.After replacing the defective part, the assembly is carried out in the reverse order. Parts that have turned out to be "superfluous" should be wiped dry and taken to the repair shop along with the hammer drill.Measures that prolong the "life" of the hammer drillAll activities boil down to the following:

Read the user manual and the instruction manual of the instrument carefully.

Strictly follow the instructions specified in the instructions.

Replace the lubricant of the gearbox and hammer regularly. Exactly replace, since there is no point in adding new grease to the used old one - metal dust serves as an excellent abrasive, "eating up" everything in its path.

Lubricate the drill shank before use.

Inspect the motor brushes regularly and replace as needed.

Clean the outside of the tool every day after finishing work.

Try not to work in clouds of dust - it is harmful not only for the hammer drill, but also for your lungs. Ventilate your work area by opening all windows.

Do not go there, in which you do not understand anything at all - entrust the service to a professional, or, if you have already undertaken to repair the puncher with your own hands, then do it slowly, remembering well where you put what.

A hammer drill is a tool without which it is impossible to imagine most of the construction and repair work today. Therefore, today every person associated with such works aspires to have this tool. A video about the repair of a hammer drill will be interesting to everyone who wants to be able to independently repair the breakdown of this tool.To know what exactly needs to be repaired, it is worth understanding the reasons for the breakdown of the hammer drill. This video will help you to do this.

Just imagine that your tool suddenly stops working or you urgently need to replace any defective part. The easiest way is to take the hammer drill to a service center for repair, but this takes time, which means it will stop your work for a while. But if you know how the device is disassembled, 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 there will be no need to spend money on paying for the services of repair centers.Instructions for parsing the tool:

We start work, starting from the upper unit: first, the rubber tip is removed, then the washer, the spring, the ball finishes working.

After you have removed the ball, we unscrew the screws that hold the case, remove the cover on the handle, if available, and lastly disconnect the stator wires.

We remove the brush holder.

The next step is to separate the gearbox and housing until a gap forms. It is through it that we will retrieve the switch.

After that, the punch body is placed vertically, with the help of a vise, it is fixed, 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 normally.

Repair kit of rubber sealing rings for the Bosch rotary hammer 2-26

When the drunk bearing, pos. 830, is destroyed, the rotary movement of the intermediate shaft cannot be converted into the translational movement of the cylinder in the percussion mechanism.

Eliminated by completely replacing the rolling bearing.

Friction bearing

There are times when the drummer bites into the cylinder poz.26, which leads to the destruction of the cylinder and the impossibility of creating air pressure in the barrel of the impact mechanism. And the second reason: destruction or breakage of the striker pos. 28, leading to the curvature of the part and the impossibility of transmitting the shock impulse.
Breakdowns are eliminated by complete replacement of the failed parts.

The striker is jammed in the piston, the destruction of the piston

The malfunction is eliminated by repairing the clutch or completely replacing it.
During repairs, worn-out teeth are filed on the clutch. To correct this defect, a round file and a drill are used. The clutch is clamped in the hand, and the tooth profiles are straightened with a drill with an appropriate file. The splines on the intermediate shaft are modified in a similar way.

Restoration of the teeth of the intermediate shaft clutch

When the spring pressure (pos. 50) decreases, the clutch slips on the intermediate shaft, without transferring rotation from the small spur gear to the large gear (pos. 22) of the barrel shaft (pos. 821) of the percussion mechanism. By the way, the clutches are arranged differently on different Bosch models.

Details of the unit for transmitting the torque and translational impulse

The large gear wheel, pos. 22, is mounted on the shaft of the barrel, pos. 01, by the roller, pos. 88, pressed against the shoulder of the shaft by a conical spring, pos. 80, and fixed with a retaining ring, pos. 85.

The reason may be a weakening of the force of the conical spring, pos. 80, destruction of the retaining ring, pos. 85, falling out of the fixing roller, pos. 88.

Gear wheel pos. 22 on the shaft pos. 01 of the barrel pos. 821 of the shock block assembly

Bosch rotary hammers use two types of chuck: SDS-plus and SDS-max. The difference is in the design of the locking mechanism.

The reason is the wear of the antennae of the raster sleeve of the chuck, which leads to the impossibility of transmitting the shock pulse to the working tool of the perforator.

Tool shanks of Bosch rotary hammer chucks 2-26

There is a rotation of the gears with cutting teeth on one of them, more often on a small one.

When the working tool is jammed and the clutch does not work properly, wear or complete destruction of the gear teeth on the perforator shaft and the intermediate shaft occurs.

In this case, the rotor or the large gear of the intermediate shaft is completely changed.

Rotary hammer bosch 2-26 with cut splines

The reasons for a not working electric motor can be:

short circuit in the rotor, stator;
destruction of coal electric brushes;
weakening of the fastening of the brush holders;
burnout of lamellas on the rotor manifold;
breakage of the rotor or stator windings.

The listed malfunctions are eliminated by repair (rewinding the winding manually, replacing the collector and wiring the winding leads) or replacing the rotor, stator, carbon electric brushes with new ones.
The main part of the malfunctions of the electrical part of the Bosch 2-26 rotary hammer is confirmed by increasing sparking in the collector area.

The length of serviceable electric brushes cannot be less than 8 mm. When replacing one brush, the second should change automatically.

The rotor or stator windings can be rewound independently with your hands at home.

Burnt manifold of the rotor of the Bosch rotary hammer

The reason for this malfunction is a break in the wire that supplies power to the electric motor. Most often, a break occurs at the point where the cable enters the puncher. The wire should be replaced with a new one or repaired. The malfunction can be determined with a tester. If there is no tester, the fault can be found using the power phase and a screwdriver with an indicator neon lamp. Connecting the power wires in turn, at the other end, using a neon screwdriver, determine the presence or absence of a phase.

The punch power button does not work. Determined by the short circuit tester.

Most often, a short circuit of the filter capacitor leads to the failure of the punch button. It is best to replace the button with a new one.

Power cord pos. 5 at the entrance to the tool

Failure of the punch in the electrical part is accompanied by the appearance of a burning smell, strong heating of the tool during operation, the appearance of large sparking in the area of the punch rotor collector, and poor response of the reverse switch.

The operation of the perforator is influenced by the condition of the carbon brushes, the reliability of the attachment of the brush holders and their correct installation.

A burning smell appears when the stator or rotor windings are short-circuited.

A drop in the power of the perforator with increasing load is characteristic when there is a break in the rotor windings or with a short length of carbon brushes.

A short inter-turn circuit in the stator or rotor most often leads to heating of the perforator.

Large sparking in the collector area is caused by interturn closure of the rotor or burnout of the collector lamellas.

Disruption of the reverse switch occurs due to the burning of its contacts.

But the main reason for all breakdowns is the untimely performance of technical maintenance work and the replacement of carbon brushes.

Carbon brushes need to be replaced after 70 hours of operation or when worn up to 8 mm in length.