Which hammer drill to buy for home use. How does a rotary hammer differ from a drill in terms of functions and performance? Rotary hammer technical specifications

Everyone who worked apartment renovation, at least once in my life I thought about the issue of purchasing such a tool as a hammer drill. So, what are tools of this class needed for and how can they be useful when carrying out repair or construction work?

A hammer drill is an indispensable device in construction. However, it requires constant care.

Hammers are a class of electric tools that are designed to make holes in building materials high hardness, such as stone, concrete, brick. They, depending on the initial characteristics, can be used in three different modes: drilling, impact + drilling and just impact work. Also, some types have a screwdriver function. The world's first instrument of this class was created in 1932 by the German company BOSH.

The main difference between a hammer drill and an equally popular tool such as a drill is the impact mechanism, which has an electro-pneumatic or electromagnetic operating principle.

Main characteristics of the rotary hammer

The main characteristics of this electrical equipment, depending on the class, are:

Force (from 1 to 20 J). This parameter determines size limit(diameter) of the hole being drilled and depends on the power.
Power (from 450 to 2000 W).
Spindle speed (from 230 to 2300 rpm).
Impact frequency (from 2150 to 5800 beats/min).
Type of installed cartridge for attaching nozzles: SDS+ (for nozzles with a diameter of up to 30 mm) and SDS-Max (for nozzles with a diameter of up to 52 mm). The attachments can be drills, drills, chisels, crowns, etc.
Tool weight (from 2.2 to 12 kg);
Additional equipment. Depending on the price, technical characteristics and equipment manufacturer, the delivery package may additionally include spare parts, replacement handles, a set of nozzles of various diameters, shapes, etc.

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Classification of rotary hammers

Depending on the technical characteristics, these electrical appliances can be divided into:

by the number of provided modes of use: one-mode (drilling only), two-mode (drilling, impact and drilling) and three-mode (drilling, impact and drilling, impact);
by type of engine placement in the device body (horizontal and vertical or L-shaped);
by weight of equipment (light – up to 3 kg, medium – 3-5 kg, heavy – more than 5 kg);
according to technical parameters and purposes of use (domestic, professional);
according to availability useful functions and characteristics (locking and safety mechanisms, reverse, adjustment of use parameters, additional lighting, etc.).

To make a final decision about which hammer drill is better, let’s make a small comparison of the most common equipment models presented on modern market power tools.

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Comparison of rotary hammers

First, let's look at and compare the characteristics of the most popular modifications of household rotary hammers.

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Household hammer drills

The BOSCH PBH 2100 RE rotary hammer has minimal power and an affordable price; it can be used for working with concrete structures.

Basically, these models have the following technical parameters:

force – from 1 to 4.5 J;
power – up to 900 W;
tool weight – up to 4 kg;
spindle speed – 1500-2000 rpm;
beat frequency – up to 5800 beats/min;
the engine in the housing is located horizontally;
cartridge for SDS+ nozzles;
number of modes of use – from 1 to 3.

First in the line of household devices, we will consider the simplest, low-power and inexpensive hammer drill BOSCH PBH 2100 RE. Its main characteristics:

weight – 2.2 kg;
three modes of use;
power – 550 W;
force – 1.7 J;
highest frequency of beats per minute – 5800;
additional options: reverse, protective coupling, auxiliary equipment.

This type at minimum power and affordable price can already be used for work with concrete structures.

A more sophisticated model in this line of rotary hammers is the BOSCH PBH 2900 RE tool. For comparison, here are its main characteristics:

weight – 3.0 kg;
three modes of use;
power – 730 W;
force – 2.7 J;
additional options: Vario-Lock function, which allows changing the angle of inclination of the working plane of the tool; reverse, protective clutch, auxiliary equipment, plastic container for storage and transportation.

This tool can be used when working with hard grades of concrete. Like all BOSCH models, it has an excellent price-quality ratio, as well as excellent ergonomics.

Finally, as the third common modification of household rotary hammers from the BOSCH company, let’s consider the PBH 3000-2FRE. For comparison with the above models, we indicate its main parameters:

weight – 3.3 kg;
three modes of use;
power – 750 W;
force – 2.8 J;
highest frequency of beats per minute – 4000;
the maximum diameter for drilling holes in concrete materials is 26 mm;
2 speeds of use;
additional options: reverse, comfortable handles, protective coupling, auxiliary equipment, plastic container for storage and movement.

This tool can be successfully used for drilling holes, for example, for a socket, as well as for stirring solutions. This model is very popular among users.

In general, it should be noted that BOSCH household hammer drills are optimal for home use and repairs. The models of this company are easy to use, have an affordable price level and are highly ergonomic.

In addition to the equipment of the above-mentioned German company, tools from the Austrian company STERN are presented on the domestic market. Let's look at some representatives model range household hammer drills from this company.

So, the STERN RH-24A modification is the simplest of this kind of equipment from this company. Its main characteristics:

weight – 2.4 kg;
three modes of use;
power – 620 W;
force – 3.0 J;
additional options: reverse, auxiliary equipment, plastic container.

The STERN RH-30E hammer drill is the most powerful of the above and is very convenient for large-scale work on concrete structures.

This model is very convenient in the process of installing structures from various types materials ( metal profile, drywall), and it is indispensable when working at heights. Next, for comparison, we will consider the more powerful STERN RH-26G tool. It has the following parameters:

weight – 6.0 kg;
three modes of use;
power – 800 W;
force – 3.0 J;
highest frequency of beats per minute – 4000;
the maximum diameter for drilling holes in concrete materials is 26 mm;

An even more powerful representative of this series is STERN RH-30E. It has the following characteristics:

weight – 4.7 kg;
three modes of use;
power – 900 W;
force – 5.0 J;
highest frequency of beats per minute – 3000;
the maximum diameter for drilling holes in concrete materials is 30 mm;
additional options: reverse, assorted accessories, plastic container.

This model is the most powerful of the above and is very convenient for large-scale work on concrete structures.

In addition to tools from BOSCH and STERN, attention should be paid to other manufacturers, for example, the famous Japanese brand MAKITA. This company produces a wide range of rotary hammers. Let's look at the most popular household models of this brand.

So, most simple model with low power – MAKITA HR 1830. Its main parameters:

weight – 1.7 kg;
power – 440 W;
force – 1.2 J;
highest frequency of beats per minute – 5000;
the maximum diameter for drilling holes in concrete materials is 18 mm;
additional options: reverse, protective coupling, screwdriver, auxiliary equipment, plastic container.

This small, compact hammer drill performs well for simple installation tasks, but it has a limited set of functions.

The HR 2020 hammer drill has great power and is quite easy to use.

To perform more complex manipulations, you will need a modification of HR 2020, which has the following technical parameters:

weight – 2.3 kg;
two modes of use (drilling, hammering and drilling);
power – 710 W;
force – 2.2 J;
highest frequency of beats per minute – 2050;
the maximum diameter for drilling holes in concrete materials is 20 mm;
additional options: reverse, auxiliary equipment, polymer container.

The model has relatively high power, is quite easy to use and inexpensive. The main drawback is the lack of a “kick” mode.

The HR 2450 modification is more powerful and more functional compared to the HR 2020 model. It has the following parameters:

weight – 2.4 kg;
three modes of use;
power – 780 W;
force – 2.7 J;
highest frequency of beats per minute – 4500;
the maximum diameter for drilling holes in concrete materials is 24 mm;
additional options: reverse, protective coupling, auxiliary equipment, polymer container.

The tool is versatile, comfortable for long-term use, and has a low body temperature.

In addition to the above-mentioned global brands, rotary hammers are also produced by other manufacturers, for example, BLACK@DECKER (USA). The most popular model of this company available in the retail chain is the KD970KA. Here are its main characteristics:

weight – 2.9 kg;
two modes of use (drilling, hammering and drilling);
power – 750 W;
force – 2.2 J;
highest frequency of beats per minute – 4850;
the maximum diameter for drilling holes in concrete materials is 20 mm;
additional options: reverse, screwdriver, polymer container for storage and transportation.

The BLACK DECKER hammer drill is easy to use and suitable for solving only the simplest construction tasks.

This modification of the hammer drill has a minimal set of characteristics and modes, and therefore is not always convenient to use. It is suitable for solving only the simplest construction problems.

Thus, we have reviewed in general terms the main representatives of the class of household hammer drills presented on the domestic market. The final choice depends on the purposes for which the equipment will be used and your financial capabilities.

It should be noted that, in addition to household hammer drills, there are also professional tools, which are also quite widely represented in the assortment of retail chains. To make a final decision on choosing a particular model, you should consider and compare the characteristics of the most popular models of pro-class rotary hammers. The main applied difference between household-grade modifications and professional models lies in two characteristics: the reliability of the tool, i.e. in the duration of its time between failures, and in the duration of use of the tool without interruption. However, it should be noted that professional versions of hammer drills are approximately 3-5 times more expensive household options. In addition, any power tool will sooner or later need after-sales service, so it’s worth considering the additional costs of maintaining the device.

Now you should familiarize yourself with the most common representatives of professional models of rotary hammers available in the retail chain.

During repairs, it is often necessary to drill holes in stone or concrete partitions or walls, and sometimes it is necessary to remove part of the wall or cut a fairly large hole in it.

In good concrete it is quite difficult to drill even a small hole to the required depth, so for this purpose they do not use a regular drill, but an impact drill, and use a special drill for concrete. If you have to, you will have to resort to using a hammer drill.

Some people mistakenly believe that tools such as an impact drill and a hammer drill are one and the same. This is fundamentally wrong, since these tools have completely different operating principles.

The hammer drill has its own impact mechanism, while the efficiency impact drill depends entirely on the power of its motor and the force with which the user can press on the tool during operation.

When working with a hammer drill, you can apply three times less force than when working with a drill. Using a drill is possible:

drill holes in wood, metal, plastic;
drill brick (in impact mode);
screw in the screws.

A rotary hammer is a much more powerful tool, which also has a resource that is not comparable to the resource of the best impact drill. In addition to everything that a drill can do, a hammer drill can:

drill stone and reinforced concrete;
perform chiselling with different chisels, with which you can make a break in the wall or make gutters for
drive in the rod;
beat off tiles or uneven concrete;
perform tamping.

Classification of rotary hammers

To classify this type of tool, you can. For example, according to the area of application, all rotary hammers are divided into:

Household.
Professional.

According to the method of positioning the device motor relative to the shock axis, the units can be divided into two types:

Horizontal - the axis of the electric motor is located parallel to the shock axis of the device. Such hammer drills have an elongated shape and are convenient for working in narrow openings.
Vertical - the motor axis is located perpendicular to the impact axis of the tool, and its shape resembles the letter L. A special feature of these devices is good cooling engine.

Additional Tool Features

In order to make work as convenient and safe as possible, manufacturers supply their:

Switch stopper – makes it possible not to keep your finger on the switch all the time, which makes work easier and relieves excess stress from your hand.
Anti-vibration system – dampens vibrations. Expensive instrument models are equipped with this function.
Depth Gauge – Allows you to determine when the hole has reached the required depth.
Soft start - reduces vibrations of the hammer drill immediately after it is turned on.
Speed mode switch - makes it possible to change the speed according to the task.
Reverse function - helps to free a stuck drill.
Drilling and chiselling switch – allows you to change the operating mode of the tool “on the fly”.

Some rotary hammer models do not have certain functions, so you need to pay special attention to this when purchasing.

How to choose a tool when buying

When purchasing a device, be sure to test it on the go. Turn on the hammer drill and listen carefully - the device good quality works without noise or noise.

Then the selected model must be turned on, and when it reaches maximum speed, turned off. Pay attention to how the stop occurs - the speed should decrease smoothly, and not stop abruptly.
Ask the seller about the availability of service centers of the manufacturer in the city. Check the availability of warranties and the warranty period.

How to work with a hammer drill

Any instructions for the tool suffices to use it:

Before installing or changing attachments, the tool must be disconnected from the mains.
The nozzle shank must be lubricated with grease.
The nozzle is inserted into the cartridge.
The hammer drill is connected to the network, and pressing the trigger starts it. The cartridge should rotate without impact.
Drilling is carried out without putting pressure on the working tool - this can lead to destruction of the drill.
After each hole, the drill must be cleaned of dust and crumbs.
The tool equipment must match the type of work performed.
It is necessary to ensure that the tool does not overheat - this will reduce its service life.
It is recommended to use thick rubber gloves when working - this will additionally protect the worker from vibration.
It is necessary to ensure that there is always lubricant in the gearbox.

– this means operating power tools as efficiently as possible on a construction site. Ultimately, this knowledge determines how accurately in terms of its parameters it will correspond to certain operating conditions, and how long and reliably it will serve its owner.

But before we get to design features, consider the principle of operation and range practical application hammer drill as one of the most popular builder's tools today.

Hammer and its purpose

Specified electrical construction tool is a fairly powerful drilling device, different from a traditional electric drill and a more modern impact drill.

The hammer drill differs from the first one, in addition to the drill rotation function, by the presence of longitudinal-axial movement of the nozzle. Reciprocating motion is also present in the operation of an impact drill. But in the scheme of its operation, this possibility is achieved by the interaction of two toothed ratchets, while impact action The hammer drill is ensured by the use of a special pneumatic or electromagnetic mechanism.

Thanks to this, the specified power tool with its working body acts on the surface being processed with greater force than an impact drill. In addition, the ratchets of the drill clinging to each other cannot provide the drill with a sufficiently large amplitude of longitudinal movement, which, for its part, is different from a standard hammer drill.

This feature determines the scope of its practical application.

The hammer drill is designed for drilling holes in particularly hard materials (brick, natural stone, concrete).
Moreover, it does this much more efficiently, better and faster than the same impact drill.

Modern models are distinguished by their versatility. This is facilitated by the ability to work in 3 modes. To mode conventional drilling(like a drill) and drilling with simultaneous impacts, a jackhammer mode is added. The presence of this mode allows you to use the device for cutting grooves in plaster, in lightweight concrete and other relatively soft building materials.
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Main types of rotary hammers

All power tools known today are divided into household and professional.

The second most important division of rotary hammers is based on the type of drive used for their design:

Network electric hammer drills. Work only from local electrical network. For this reason, their operation is limited to the presence of a stationary outlet in the immediate vicinity of the place of operation.

Cordless electric hammer drills. They can be powered either from a local power supply or from a built-in battery. This feature makes them convenient for façade and other work away from a fixed network. Moreover, they can be equipped with lithium-ion, nickel-cadmium or nickel-metal hydride batteries.

Pneumatic hammer drills. They are used in cases where work is carried out in difficult conditions, in particular, when there is a danger of an explosion, electric shock to a person, a short circuit due to the abundance of water, etc.

Gasoline hammer drills. Such systems are used under conditions of heavy and prolonged loads far from sources of electricity (for example, during large-scale road works).

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Features of the hammer drill design

The impact pulse of a power tool directed at the surface being processed is created by either an electromagnetic or pneumatic unit. When using an electromagnetic mechanism, the longitudinal movement of the core is provided by two induction coils.

If we are talking about a tool with pneumatics, then in this case the blow is produced by a piston moving inside the cylinder due to the sufficient compression created in it. As a result, the striker hits the end of the working nozzle, which, simultaneously with drilling, gradually destroys the structure of the material being processed.

Currently, rotary hammers with two types of electric motor arrangement are in use: horizontal and vertical. The first type is mainly used in light household devices, the second - in medium and heavy (professional) tools.

Due to this design, devices with a horizontal engine are usually more compact and more convenient for drilling in hard-to-reach places. However, this arrangement has a number of noticeable disadvantages. In particular, longitudinally mounted engines experience increased shock load during operation, and also cool somewhat worse and more slowly than vertical engines.

Accordingly, rotary hammers with a vertical electric motor layout do not have these disadvantages. At the same time, such a scheme provides a sufficiently large amplitude of movement of the piston-striker pair. This happens due to the use of a special crank mechanism in the tool, which increases the piston stroke. As a result, rotary hammers with a vertical electric motor can withstand intensive use better than models with a horizontal motor.

The impact pulse mechanism is the most important block of any hammer drill. The efficiency and reliability of the entire perforating device ultimately depends on its efficiency and reliability.

As mentioned above, rotary hammers, based on the principle of shock pulse formation, are divided into electromechanical and electropneumatic. At the same time, pneumatic-based tools make up the vast majority of products in use today.

Electro-pneumatic tools have gained such popularity because they develop significant shock pulse energy with a minimum rated power of the electric motor. Pneumatic impact is provided either by a scheme with a “drunk” (swinging) bearing (light and partially medium hammer drills) or a crank mechanism (medium and heavy machines).

Modern rotary hammers use two types of anti-vibration systems: active and passive. The first option is used exclusively in models with a powerful power unit, the second - in “weaker” models. The basis of this system is a counterweight with a shock-absorbing spring, which absorbs the recoil energy.

The transmission of rotation from the electric motor to the working chuck is provided by a gearbox. At the same time, it activates the impact mechanism. The gearbox is an interconnected system of gears of various configurations and is characterized by a certain gear ratio. This number is changed by an electronic regulator.

The device body can be either metal or plastic. But most often in its manufacture they combine metal with impact-resistant plastic.

Thus, a hammer drill is a rather complex device, the design of which is optimally “tailored” to specific functional tasks for processing particularly hard building materials.

A hammer drill is a tool designed to make holes. Its operation is ensured by the simultaneous impact-translational and rotational movement of the drill. Unlike drilling, the hole is not cut by the sharp edge of the drill, but is made by mechanized rotation of the working element. To create the impulse that is necessary for the operation of the tool, a pneumatic or, in rare cases, an electromagnetic mechanism is used. In application and design it is similar to a drill.
Species
Depending on the type of drive, the hammer drill is:
Networked Electrical Tools. This is the most common type; their electric motor can be located both vertically and horizontally.

Cordless electric tools. They are convenient for working in places where there is no electrical network. The battery on such units is in most cases located directly on the body of the power tool.

Pneumatic tools. They are used to work in unsafe environments. For example, if there is a danger of a gas explosion, because the slightest spark can lead to an explosion. Or when working in a damp environment, as the likelihood of electric shock increases significantly.

Gasoline. They are best suited for on-site road work.

Depending on the type of work, a hammer drill can be industrial or household. Most of them are industrial. Household devices Typically used for moderate load work.
Based on its weight, a hammer drill can be of three types:
Lightweight - up to 3 kg. It is used to create a small hole for an anchor or dowel.
Medium - up to 5 kg. Used for chiseling reinforced structures. Can be used for processing high hardness stone.
Heavy - over 5 kg. This tool can replace even a small jackhammer. It is often used for impact drilling of concrete having a thickness of 30-60 mm.

The division also occurs according to the modes used:
Single-mode tools - used only for drilling.
Dual-mode - used when drilling with impact is necessary;
Three-mode - in addition to conventional drilling and hammer drilling, they are used for chiselling.

Device
Depending on the functionality, manufacturer and power of the tool, its design features may be different. However, despite this, the main elements remain unchanged:
The main element is the electric motor, which can be made in a vertical (heavy and medium) or horizontal (light) design. The horizontal layout makes the device compact, however this design involves a high shock load on the motor. The vertical design ensures efficient cooling of the engine, thereby improving the quality of its operation. This layout is best suited for intensive work.
The most important component is the impact mechanism. It can be pneumatic, mechanical or electromechanical.
Gearbox. It is used to transmit torque to the chuck axis from the engine and simultaneously reduce the rotation speed.
Anti-vibration system. It has a significant impact on the quality of the work performed, including the health of the craftsman who works with the tool.
The body of the device, which is made of impact-resistant plastic or metal.
Electrical diagram. Used to control the rotation speed of the motor.
The safety clutch allows you to stop the chuck in a situation where the tool jams in the hole. It provides protection to a person’s hands from possible injuries.

Additionally, the hammer drill can be equipped with additional systems that make the use of the device comfortable or expand its capabilities. These include:
Mechanism for fixing drilling depth.
Work element fixation system.
System for removing dust generated in the work area.
The mechanism for changing the operating modes of the tool and so on.

Operating principle
The operating principle of the tool is based on a percussion mechanism - pneumatic, hydraulic, mechanical or electromagnetic. The impact mechanism itself is driven by the rotational motion of the motor. Electromagnetic mechanism involves the operation of two electromagnetic coils. They ensure the movement of the core in a reciprocating direction. In this case, the core transmits these impacts to the end part of the drill. The pneumatic version is provided by the movement of the piston in a reciprocating direction in the cylinder.
The pneumatic system of this unit has 2 design options - using a swing bearing, as well as a crank mechanism, which is combined with the gear part. When the shaft rotates, oscillatory rotations of the piston are formed, which pumps air into the working cylinder of the system. Cylinder due small space creates pressure compressed air, which leads to the movement of the ram and the striker.
Due to short-term impulse transitions of the ram and piston, these movements are converted into impacts. Mechanism idling, not being pressed against a hard surface, turns itself off, as a result, compression pressure is not generated, and no shocks are produced. The working mechanism itself is motionless. The rotation speed of the shaft can be adjusted by pressing a button if there is a soft start. In a number of models, the button is equipped with a regulator for setting the maximum trigger pull, which allows you to set the power and engine speed.
More complex ones can be used electronic systems- constant electronics. It maintains the specified impact energy, torque and speed under load. As a result, there is no drop in performance under heavy loads, especially at reduced speeds. In “advanced” models, armature rotation is controlled and a power reserve is activated in the event of an increase in load.
To protect the user from injury due to tool jamming, a safety clutch or release clutch is used that immediately locks. It ensures that the shaft is disconnected from the gearbox.
The tool often has to work with materials that generate a significant amount of abrasive particles and dust. They interfere with the user's work and contribute to wear on the tool barrel. To eliminate this, a number of models are equipped with dust extraction systems that suck dust from the work area.
Application
The hammer drill is used to create holes in concrete, stone, and brick building structures of increased strength by applying mechanical blows to the nozzle, which performs a combined translational and rotational movement.
In addition, the tool can be used for the following operations:
Applying axial blows in jackhammer mode.
Drilling holes in various materials through the use of the drill function.

To provide versatility, many manufacturers provide the tool additional functions and offer a set of special attachments that allow:
Prepare different construction solutions.
Drill holes.
Perform grinding.
Clean concrete, stone and metal surfaces.
Perform many other tasks.

Perform additional operations:
For drilling, the conventional chuck is replaced with a quick-release chuck SDS Plus (SDS Max). Then install a drill that matches the type of material. The tool is switched to rotation mode, in which the work is carried out as a regular drill.
Grilling. This function is necessary when dismantling the old ceramic tiles, gaskets electric wire in the wall, etc. To do this, a chisel is clamped into the chuck. The angle of the chisel is adjustable so that you can conveniently work with the required surface. The position of the chisel is fixed by a special lever, which is located on the body of the hammer drill. The tool is used in chiselling mode without rotation.
Drilling (perforation) – a drill is fixed into the chuck. The work is carried out in rotation mode with impact.
Surface destruction. A lance with a wide spatula is attached to the cartridge. The slotting mode without rotation is used.
Tightening the screws. The chuck is replaced with a quick-release chuck. The tool operates in rotation mode without impact. For this operation it is recommended to use a small tool. For a large number of screws, it is better to use a drill or screwdriver.

Advantages and disadvantages
The advantages include:
A rotary hammer has an order of magnitude greater impact force than a conventional impact drill. This allows you to punch holes in concrete, bricks or cinder blocks faster.
The tool can work with various additional attachments that are specifically designed for it.
Significantly longer service life.
Wide range of applications.
The productivity of the hammer drill when working on hard material is much higher.

The disadvantages include:
The instrument is quite heavy.
A hammer drill and its accessories are significantly more expensive than an impact drill, if you take devices of the same power.
Conventional drills cannot be used in a hammer drill without an adapter, which leads to lengthening of the structure and complication of the drilling operation. This reduces the service life of the tool.

A hammer drill is a power tool used for dismantling building structures made of brick and concrete, as well as in special durable materials. With its help you can easily remove from the surface old tiles, punch an opening in the wall, make a groove in it for laying the cable, and even tighten an ordinary screw.
The most famous representative of this type of tool, the Bosch rotary hammer, is equipped with a powerful pneumatic impact mechanism, which significantly increases the productivity of the device and is equipped with a number of functions that increase the ease of use.
Briefly about the history of the brand
The history of the BOCH brand began in 1886 in Germany. It was then that engineer Robert Bosch opened the country's first electrical workshop. Under this brand, at the beginning of 1932, the world's first electric hammer saw the light of day. In the spring of 1961, the company's engineers patented a new pneumatic operating principle for this tool. At the end of 1946, the company produced the first, and in 1984, the Bosch hammer drill, powered by a battery.
Today the concern is one of the world leaders in the production of quality goods that make human life easier. The company consists of 300 enterprises and more than 13,000 service centers, which are located in 140 countries. Its product range includes, in addition to a variety of power tools, also high-quality household and garden equipment, as well as batteries and saws.
General diagram of the BOCH hammer drill
The design of German brand rotary hammers is represented by a complex but absolutely thought-out system, all of whose components affect the efficiency and performance of the tool.
1. Cartridge.
2. Impact mechanism.
3. Safety coupling.
4. Electric motor.
5. Cable entry.
Let's look at the main parts and elements that the Bosch hammer drill is equipped with in more detail.
SDS keyless chuck
The device is used to attach working attachments to the unit, prevents them from turning and ensures easy replacement. BOCH rotary hammers are equipped with two types of chucks:
SDS-max. For bits with a shank diameter of 18 mm. The chuck is characterized by the presence of 5 grooves (3 open - for insertion; 2 closed - for fixing) and is suitable for attaching a drill with a working diameter of more than 25 mm.
SDS-plus. For attaching bits with a shank diameter of 10 mm. The device is characterized by the presence of 4 slots (2 open and 2 closed). Lightweight models of rotary hammers are equipped with such chucks, the drills of which can drill holes up to 25 mm.

Impact mechanism
Each Bosch rotary hammer is equipped with a powerful impact mechanism that operates on the principle of a pneumatic system.
As a result of the reciprocating movements carried out by the piston (2), receiving an impulse from the swinging, or, as it is also called, “drunk” bearing (1), compression is created, causing the damper-ram (3) with the striker attached to it to move - drummer (4).
It should be noted that this entire system is driven by the motor gear (5). The result of the mechanism is the blows that the striker delivers to the end part of the nozzle (drill or blade). In some professional models, the “drunk” bearing of the unit is replaced by a crank mechanism.
Safety coupling
Long-term "Bosch" is a rather rare phenomenon, since its mechanical design includes a protective clutch that stops the rotation of the tool gears when the drill gets jammed in the hole. The presence of such a mechanism not only avoids damage to the unit itself, but also ensures the safety of the user working with it.
Electric motor
All German-made tools are equipped with high-quality electric motors, varying in size and power consumption (from 400 to 1500 W). From this diagram of Bosch rotary hammers it is clear that the engine is horizontal. It should be noted that in most powerful professional models it is located vertically.
Cable entry
All rotary hammers of the German company are equipped with a hinged cable entry, which prevents chafing of the electrical wire and increases the comfort of working with the device, increasing its mobility. The structure of this unit allows you to rotate the tool at the desired angle, penetrating into the most hard to reach places building structure.
Gearbox
Many units are equipped with a two-speed gearbox, which allows you to increase the shaft speed without reducing the performance of the device. If you are thinking of purchasing a tool for your home, then the Bosch hammer drill will be recommended to you. The price of this unit, however, will be significantly higher than that of its gearless counterparts.
Rotary hammer characteristics
The Bosch rotary hammer, like any representative of this type of power tool, has three main characteristics that determine its performance:
Spindle speed- determines the rotation speed of the working tool. This indicator affects the efficiency of the unit in drilling mode and can range from 600 to 2000 rpm. depending on the hammer drill model. Note that powerful professional devices have a lower rotation speed of the working mechanism, since the diameter of their equipment is much higher than that of household tools.
Impact energy- depends on the engine power, the weight of the striker and the length of its working stroke. It is the main characteristic that determines the performance of the unit, and ranges from 1.2 J for “amateur” models to 14.2 J - the impact force of the most powerful Bosch hammer drill. The price of such a professional device, however, exceeds 48,000 rubles.
Impact frequency- is determined by the number of strikes of the striker on the end of the working nozzle over a period of time equal to one minute. The speed of drilling holes depends on this characteristic, and together with the impact energy it determines the performance of the hammer drill. U various models this figure can vary from 1100 to 5500 beats/min.

German brand equipment is distinguished by its selection optimal ratio all these parameters, which makes it truly reliable and high quality.
Tool operating modes
A clear advantage of the Bosch rotary hammer is its ability to operate in various modes:

Classification of units
So, we noted that BOCH rotary hammer models have differences in the power of electric motors, spindle speed, as well as the frequency and force of impacts. This allows you to divide all units into the following types:

Depending on the power source, BOCH rotary hammers are divided into electric, powered by a 220 W household power supply, and rechargeable, powered by a lithium-ion or nickel-cadmium battery. Devices of this type are indispensable when working in places remote from power sources or in de-energized rooms.
Additional functions of units
Regardless of the type and brand, most models of this German technology are equipped with a set of functions that increase the performance and ease of use of the devices. Almost all units are equipped with:

Thanks to the various capabilities of the devices, any user - from a professional builder to a simple home handyman- will be able to choose a Bosch hammer drill that suits his needs. Reviews about this tool are only positive and speak of its versatility, efficiency and consistently high quality.