EP1910038B1 - Linearly driven and air-cooled boring and/or percussion hammer - Google Patents

Abstract

The invention relates to a boring and/or percussion hammer comprising an electrodynamic linear drive and a pneumatically damped percussion mechanism which is provided with a drive piston (1) driven by the linear drive during the reciprocating movement thereof, an impact piston (3) and a pneumatic spring (7) arranged between the drive and impact pistons. An air-supply device comprises a pumping element (13), which is linearly forth and back movable for generating airflow. The pumping element (13) is connected to the drive piston (1) in such a way that the movement thereof is transmitted to said pumping element (13), thereby the cooling air is transported by an air channel (15) for cooling heat generated elements (12).

Description

The invention relates according to the preamble of claim 1 a drilling and / or percussion hammer with an electrodynamic linear drive. Such a hammer and / or hammer is from the US-A-1 723 607 known.

Drilling and / or impact hammers (hereinafter referred to as hammers) are usually driven by electric motors in which a rotor rotates a drive shaft. For cooling the motor and hammer mechanism provided in the hammer, the rotor is usually coupled to a fan of a fan, which generates a cooling air flow. The rotational movement of the rotor is thus used in a simple manner for driving a radial or Axiallüfterrades.

From the DE 102 04 861 A1 An air spring impact mechanism is known in which a drive piston can be driven by an electrodynamic linear drive. The drive piston is coupled to a rotor of the linear drive, so that the linear reciprocating motion of the rotor is transmitted to the drive piston. The movement of the drive piston, in turn, is transmitted via an air spring to a percussion piston, as is usual with air spring impact devices, which strikes against a tool end or an interposed anvil in a known manner.

In such a striking mechanism with linear drive principle no rotating components are provided. Accordingly, no rotary blower can be coupled in the simple manner, as is the case with a rotary drive. However, heat is generated by the linear actuator and the air spring impactor during operation of the hammer, which must be dissipated.

In the US 1 723 607 A is shown a percussion hammer, which has a directly linear electrodynamically driven impact element. The impact element and a drive element form a functional unit and are rigidly or positively connected firmly. Chambers lying in front of and behind the impact or drive element are connected to themselves and to the ambient atmosphere via ducts. When the hammer mechanism is in operation, the volumes in front of and behind the impact element change in opposite directions. Due to the connection of both chambers, air is exchanged between the two chambers.

The invention has for its object to provide a drilling and / or percussion hammer with an electrodynamic linear drive, in which a sufficient air cooling of the heat-generating components is ensured.

According to the invention the object is achieved by a drilling and / or percussion hammer according to claim 1. Advantageous embodiments of the invention are indicated in the dependent claims.

An inventive hammer drill and / or percussion hammer (hereinafter referred to as hammer) has an air-conveying device with a linearly reciprocable pumping element for generating a cooling air flow. The pumping element is coupled to the drive element and / or the striking element of the percussion mechanism in such a way that the movement of the drive element and / or of the striking element can be transferred to the pumping element.

In the hammer according to the invention, the air conveying device has a pumping space and an air duct, wherein the pumping element can be moved back and forth in the pumping space and the pumping space can be brought into contact with the environment at least temporarily via the air duct. By the movement of the pumping element in the pumping space, a type of air pump is formed, which functions similar to a bicycle pump (piston pump). Due to the coupling of the pump chamber with the environment via the air duct, there is the possibility that fresh cooling air can be supplied from the environment into the pump chamber or heated air can be released to the environment.

In the hammer according to the invention, the air channel has an intake passage for the inflow of. Air from the environment in the pump room. Accordingly, the air duct also has an outlet channel for the outflow of air from the pumping space into the environment. While in a variant not according to the invention the ambient air is conveyed back and forth in the air duct, when the air duct is divided into an intake duct and an exhaust duct a directional air flow can be achieved, which always flows only in one direction. Accordingly, cold air from the environment is supplied via the intake passage while the heated air is discharged to the environment via the exhaust passage.

The drive element can, for. B. are formed by a drive piston in an air spring impact mechanism. It is reciprocated by the linear drive in a known manner. According to the invention, the pumping element is coupled to the drive element in an advantageous manner, so that it likewise has to reciprocate linearly. With the help of this oscillating linear movement, a cooling air flow can be generated, which is guided past the components to be cooled. The linearly driven air conveying device makes it possible to generate a cooling air flow without having to provide a rotary ventilator.

In an advantageous embodiment of the invention, the drive element is connected to a rotor of the linear drive. In particular, it is advantageous if the drive element carries the rotor or is substantially completely formed by the rotor, so that the rotor simultaneously assumes the function of the drive element.

The linear motor can be a switched reluctance motor (SR motor) and has several drive coils (stator) in the movement range of the rotor, which are switched according to the desired movement of the drive element. It should be noted that as a linear motor in connection with the invention, an electrodynamic drive z. B. is considered in the form of a single electromagnetic coil, which serves as a drive coil for the drive element. The return movement of the drive element can then z. B. via a coil spring o. Ä. respectively. Decisive is that the drive element is closely connected to the rotor.

In an advantageous embodiment of the invention, the coupling device has at least one between the drive element and the striking element effective stop. The stop ensures a positive transmission of the movement of the drive element to the striking element, which must then necessarily follow the movement of the drive element.

In a preferred embodiment, the coupling device has an elastic element acting between the drive element and the striking element in at least one direction. Thus, it is possible to design the stop described above elastic, z. B. by a stopper held on the elastic element or an elastic coating. Alternatively, the elastic element may also be formed by a later explained air spring, when the percussion is realized as Luftfederschlagwerk.

In a particularly advantageous embodiment of the invention, the drive element, the rotor and the pumping element form a structural unit. In particular, these components can be integrally connected to each other, so that the movement of the rotor can be transferred lossless to the drive element and the pumping element. The drive element and the pumping element must then necessarily follow the movement of the rotor.

In one embodiment of the invention, the movement of the drive element via a mechanical, hydraulic or pneumatic coupling to the pumping element is transferable. For example, a Bowden cable or a hydraulic line can run between the drive element and the pump element in order to transmit the movement of the drive element to the pump element with as little loss as possible. In this variant, it is not necessary that the drive element and the rotor form a structural unit with the pumping element. Rather, the pumping element can then also be arranged at a different location in the hammer.

In a particularly advantageous further development, the pumping element is arranged in a region of the hammer which is decoupled from the impact mechanism in terms of vibration. The impact mechanism and the linear drive generate considerable vibrations due to the oscillating motion of the moving elements and the impact of the striking element. From the prior art, many approaches are known to reduce these vibrations z. B. to isolate from a handle of the hammer and to protect the operator from harmful vibrations. Accordingly, it is known in almost all hammers to decouple at least a portion vibrationally from the percussion. The arrangement of the pumping element in this vibration-decoupled region has the advantage that the pumping element and the remaining components of the air-conveying device are mechanically stressed less, so that a more reliable mode of operation can be achieved.

Preferably, the rotor is designed substantially cylindrical or hollow cylindrical. Alternatively, it may also have at least one axially extending plate-shaped or sword-like element. This plate-shaped element, the z. B. is formed as an extension on the drive element extends into the stator to achieve the desired drive effect.

Accordingly, it is particularly advantageous if the air duct is arranged such that it runs along heat-generating components of the hammer, in particular along a part of a stator of the linear drive. The stator is traversed by an electric current and accordingly contributes significantly to the heat generation. This heat can be removed from the stator via the cooling air flowing through the air duct.

To support the directed air flow, it is particularly advantageous if a check valve is arranged in the intake duct and / or in the outlet duct, which permits an air flow only in one direction.

In an advantageous further development of the invention, a storage device is provided, which is in communicating connection with the outlet channel and serves for temporarily storing at least part of the air flowing out via the outlet channel. The storage device ensures a compensation of the air pressure fluctuations that inevitably arise due to the movement of the pumping element. Pressure peaks can be reduced by the fact that the storage device briefly absorbs air. If, on the other hand, no air is supplied by the pumping element, the storage device releases the air again and thus ensures a substantially uniform flow of cooling air. For this purpose, it is expedient that an elastic or spring-loaded element is provided in the storage device, which changes the size of a storage space as a function of the pressure of the air flow supplied by the pumping element.

Preferably, a cross section of the exhaust passage downstream of the storage device is smaller than a cross section of the exhaust passage upstream of the storage device. It is thus possible that the air flow conveyed by the pumping element can reach the storage device unhindered in order to fill the storage device with as little loss as possible. The actual cooling air flow is then discharged via the outlet channel of smaller cross-section, this outlet channel extending along the heat-generating components.

In order to support a directed air flow, a check valve can be arranged in the outlet channel between the pump chamber and the storage device.

In a particularly advantageous embodiment of the invention, the pumping element is arranged in the direction of impact behind the drive element and the rotor. Alternatively, the pumping element can also be arranged next to the striking mechanism. It is desirable that the air pumping device must be arranged as space-saving as possible in the housing of the hammer in order not to increase the overall volume, especially the overall length.

In a particularly preferred embodiment of the invention, the striking mechanism is formed by an air spring impact mechanism. For this purpose, the drive element is designed as a drive piston and the impact element as a percussion piston, wherein the coupling device has a trained in a cavity between the drive piston and the percussion piston air spring. The air spring thus transmits in a known manner, the drive movement of the drive piston on the percussion piston.

The coupling according to the invention of a linear drive with an air-conveying device can be applied to all types of striking mechanisms. In particular, the coupling according to the invention is suitable for percussion, which are designed as Luftfederschlagwerke, and thus therefore known per se tube impactors (drive piston and percussion pistons with identical diameter), hollow piston impactors (drive piston with cavity in which the percussion piston moves) or drums with hollow percussion piston , in which the drive piston moves.

In a particularly advantageous, a hollow piston impact similar embodiment of the invention, the drive piston surrounds the percussion piston in the direction of impact before and behind the percussion piston such that the air spring is disposed behind the percussion piston and that before the percussion piston, a second air spring between the drive piston and the percussion piston can be formed , In this percussion type thus creates a double air spring, which on the one hand generates the movement of the percussion piston forward and on the other hand supports a return movement of the percussion piston.

In an advantageous embodiment of the invention, an effective for generating the air flow cross-sectional area of the pumping element is greater than acting on the air spring cross-sectional area of the drive piston. Depending on the design of the linear actuator and the air spring impact mechanism may be released under certain circumstances, a significant heat output, which must be dissipated. For this purpose, a correspondingly large cooling air flow is required. In order for the air conveying device to be able to generate this cooling air flow, a correspondingly large cross-sectional area of the pumping element must be present. Of course, the pumping element can also be replaced by a plurality of individual pumping elements which, taken in themselves, are dimensioned smaller, but together achieve a sufficiently large effective cross-sectional area through their coupling with the rotor and thus their interaction together. Accordingly, the term "pumping element" refers only to the function, not to the specific embodiment.

Fig. 1

in schematischer Darstellung einen Schnitt durch einen nicht - erfin- dungsgemäßen Hammer in einer ersten Ausführungsform;

Fig. 2

in schematischer Darstellung eine zweite Ausführungsform der Erfindung;

Fig. 3

in schematischer Darstellung eine dritte Ausführungsform der Erfindung;

Fig. 4

in schematischer Darstellung eine vierte Ausführungsform der Erfindung;

Fig. 5

in schematischer Darstellung eine fünfte Ausführungsform der Erfindung;

Fig. 6

in schematischer Darstellung eine sechste Ausführungsform der Erfindung;

Fig. 7

in schematischer Darstellung eine siebte Ausführungsform der Erfindung; und

Fig. 8

einen Schnitt durch eine schematische Darstellung eines Schlagwerks gemäß einer achten Ausführungsform der Erfin- dung.

These and other advantages and features of the invention are explained in more detail below by means of examples with the aid of the accompanying figures. Show it:

Fig. 1

a schematic representation of a section through a non - inventive hammer in a first embodiment;

Fig. 2

a schematic representation of a second embodiment of the invention;

Fig. 3

a schematic representation of a third embodiment of the invention;

Fig. 4

a schematic representation of a fourth embodiment of the invention;

Fig. 5

a schematic representation of a fifth embodiment of the invention;

Fig. 6

a schematic representation of a sixth embodiment of the invention;

Fig. 7

a schematic representation of a seventh embodiment of the invention; and

Fig. 8

a section through a schematic representation of a striking mechanism according to an eighth embodiment of the invention.

Fig. 1 to 8 show different embodiments of the hammer according to the invention in a greatly simplified sectional view. In particular, known per se components such. As handles and electrical connections, omitted, since they do not affect the invention.

Fig. 1 shows a first non-inventive embodiment with a driven by an electrodynamic linear actuator air spring impact mechanism.

The air spring impact mechanism has as drive element a drive piston 1 which encloses a piston head 2 of a percussion piston 3 acting as a striking element. The percussion piston 3 extends with a shaft 4 in a percussion piston guide 5 and can strike in its foremost position against a tool end 6. Instead of the end of the tool 6, an intermediate header can also be provided in a known manner.

Between the drive piston 1 and the percussion piston 3, a cavity is formed, in which acts as a coupling device first air spring 7 acts. In a forward movement of the drive piston 1, which is axially reciprocable in a percussion gear 8, a pressure builds up in the first air spring 7, which drives the percussion piston 3 to the front, so that it can finally strike against the tool end 6.

In a return movement of the drive piston 1 is formed in the first air spring 7, a negative pressure, which sucks the percussion piston 3. The return movement of the percussion piston 3 is also supported by the impact reaction at the tool end 6. Furthermore, as seen in the direction of impact, in front of the piston head 2, a second air spring also serving as a coupling device is provided 9 formed, which comes into effect during the return movement of the drive piston 1. It also supports the return movement of the percussion piston 2.

To compensate for air losses in the air springs 7, 9 and to support the movement of the drive piston 1 and the percussion piston 3 are different air openings and channels, such. B. several air compensation pockets 10, is provided. Their operation is known from the prior art, so that at this point a more detailed description is unnecessary.

The oscillating, linear reciprocating movement of the drive piston 1 is effected by an electrodynamic linear drive. For this purpose, the drive piston 1 is coupled to a rotor 11 of the linear drive. The rotor 11 may be formed by a plurality of stacked electrical sheets and is reciprocated by alternating magnetic fields generated by a stator 12 of the linear drive. The operation of such a linear drive is known and z. B. in the DE 102 04 861 A1 described. In the linear motor, it may, for. B. may be a reluctance motor with external stator.

The rotor 11 and the drive piston 1 form in the in Fig. 1 example shown a one-piece unit.

Directly on the rotor 11, a pumping element in the form of a pump piston 13 is formed, which is in a pumping chamber 14 back and forth. Since the pump piston 13 is integrally connected to the rotor 11 and the drive piston 1, the pump piston 13 must necessarily follow the movement of the rotor 11. As a result of the reciprocating movement, the pump piston 13 generates an overpressure or underpressure in the pumping chamber 14.

The pumping chamber 14 communicates with the environment via an air channel 15. The air duct 15 is arranged to the hammer so that it is guided past at least a part of the heat-generating components (in this case in particular the stator 12), as in FIG Fig. 1 shown. The pump piston 13, the pumping chamber 14 and the air channel 15 form an air conveying device.

When the rotor 11 moves down together with the drive piston 1 and the pump piston 13, a negative pressure is generated in the pumping chamber 14, so that air from the environment flows in via the air channel 15 into the pumping chamber 14. In a return movement of the rotor 11 with the drive piston 1 and the pump piston 13, the now heated air is again pressed out of the pumping chamber 14 and the air channel 15. At the next cycle, fresh cooling air is drawn in again. In this way, an effective cooling in the air duct 15 can be achieved.

The pumping element is shown cylindrically on the basis of the pumping piston 13. Of course, the pumping element can also take any other forms and z. B. be formed as a prismatic disc.

Fig. 2 shows analogously to Fig. 1 a second embodiment of the invention. Identical components are identified by the same reference numerals. To avoid repetition, therefore, only the differences between the second and the first embodiment will be explained below.

In the second embodiment of the invention, the air duct 15 is divided into an intake passage 15a and an exhaust passage 15b. Air from the environment can flow into the pumping chamber 14 via the intake duct 15a when the pump piston 13 moves downwards. In a return movement of the pump piston 13, the air is discharged from the pumping chamber 14 via the outlet channel 15b to the environment.

To ensure a directed air flow, an inlet check valve 16 is arranged in the intake passage 15a and an outlet check valve 17 is arranged in the outlet passage 15b. In the Fig. 2 shown check valves 16, 17 are formed as spring-loaded balls. Of course, other types of check valves can be used. Thus, it will normally be sufficient to form the check valves by means of a rubber element attached on one side, which is lifted from a direction of a valve opening when it flows from one direction, while it is pressed in the reverse flow direction to the valve opening, and thereby closes.

Fig. 3 shows a third embodiment of the invention, which differs from the in Fig. 2 shown second embodiment differs in that in the region of the outlet channel 15b, a storage device 18 is provided. The memory device 18 is used to compensate for changes in air pressure, which inevitably arise in particular in the outlet channel 15b by the oscillating movement of the pump piston 13. The storage device 18 is able to eliminate pressure peaks by enlarging a storage space 19 against the action of a resilient element 20. As soon as the pumping pressure through the pump piston 13 decreases, the resilient element 20 causes a reduction of the storage space 19, so that an air flow through the downstream part of the outlet channel 15b is maintained.

At the in Fig. 3 As shown, the elastic element 20 is designed as a helical spring which presses against a movable wall 21. Of course, this system can also z. B. be replaced by a rubber membrane.

Fig. 4 shows a fourth embodiment of the invention in analogy to the second embodiment of Fig. 2 ,

However, in the fourth embodiment, the traveler is constituted by two sword-like plate projections 22 which are reciprocable in a correspondingly shaped stator 12.

The pump piston 13 is connected via a piston rod 23 with the drive piston 1 in connection.

In this design, the cross-sectional area of the pump piston 13 and the pumping chamber 14 can be increased, since these components are arranged behind the linear drive.

Fig. 5 shows a fifth embodiment of the invention, in which the air conveying device is arranged axially to save space next to the air spring impact mechanism.

The pump piston 13 and the pumping chamber 14 enclose for this purpose the air spring impact ring annular. Alternatively, two or more pumping pistons 13 may be provided, which are movable in respectively associated pumping chambers 14. The function of the pump piston 13 can thus be achieved by a plurality of individual pistons.

At the in Fig. 5 In the embodiment shown, the outlet channel 15b is also guided past the stator 12, in which the rotor 13 with plate extensions is movable. Of course, instead of the plate extensions 22 and a cylindrical rotor 13, as in the Fig. 1 to 3 shown to be used.

In Fig. 6 A sixth embodiment of the invention is shown, Here, the air pumping device with the pump piston 13 and the pumping chamber 14 is provided separately from the drive piston 1 and the rotor 11.

On the unit formed by the drive piston 1 and the rotor 11, a hydraulic piston 24 is formed, which via a hydraulic line 25 hydraulic fluid to a hydraulic shaft 26 which is connected to the pump piston 13. Accordingly, the pump piston 13 follows substantially loss-free movement of the drive piston 1 and rotor 11. In a striking movement of the drive piston 1, the hydraulic piston 24 lowers, so that due to the negative pressure in the hydraulic line 25, the hydraulic shaft 26 is sucked up. As a result of the thus forced movement of the pump piston 13 upwards, air flows via the quite short intake passage 15a into the pumping chamber 14, which is expelled on a return movement of the drive piston 1 and a correspondingly transmitted movement to the pumping element 13 via the outlet channel 15. The return movement can be supported by an additional spring.

The mechanical transmission of the movement of the drive piston 1 on the pump piston 13 can also be done by means of a movable, guided juxtaposition of balls in a pipe or hose connection. The pump piston 13 must then be forced by means of a spring in its starting position.

The structural decoupling of the air conveying device from the linear drive and the air spring impact mechanism, in the sixth embodiment, it allows the air pumping device to be vibrationally decoupled in the hammer. For example, it is possible to fasten the air-conveying device to a housing cover 27, which is vibrationally decoupled with respect to the linear drive and the air spring impact mechanism.

Fig. 7 shows a schematic section through a seventh embodiment of the invention. Unlike the above based on the Fig. 1 to 6 described Luftfederschlagwerken relates to the seventh embodiment according to Fig. 7 a striking mechanism in which the energy for the impact movement can not be transmitted by an air spring. Accordingly, this striking mechanism can not be called an air spring impact mechanism.

The percussion mechanism is driven by an electrodynamic linear drive in a manner similar to the above-described air spring impact devices. It has a drive unit 30, which combines the functions of a drive element and a rotor of the linear drive with each other. The drive unit 30 is in Fig. 7 shown only schematically. So z. B. the structure of the rotor is not shown in detail. With respect to the runner, however, the above for the runner 11 (eg. Fig. 1 ) details.

The drive unit 30 is similar to the manner described above in a tubular percussion gear housing 8 back and forth, wherein the movement is effected by the stator 12.

The drive unit 30 is of sleeve-shaped construction and has in its interior a hollow region in which the percussion piston 3 forming a striking element can be moved back and forth. The percussion piston 3 then strikes in a known manner against the in Fig. 7 not shown tool.

To transmit the movement of the drive unit 30 to the percussion piston 3, a coupling device is provided. The coupling device has a driver 31 carried by the percussion piston 3, in particular by the piston head 2 of the percussion piston 3, which can be moved back and forth in recesses of the drive unit 30 in the working direction of the striking mechanism. The driver 31 may, for. B. are formed by a piston head 2 of the percussion piston 3 penetrating transverse pin, as in Fig. 7 shown.

The recesses in the drive unit 30 are formed by two axially extending longitudinal grooves 32 which penetrate the wall of the hollow cylindrical drive unit 30.

At the end faces of the longitudinal grooves 32 lower stops 33 and upper stops 34 are formed, which limit the longitudinal movement of the driver 31 in the longitudinal grooves 32.

In a reciprocating motion of the drive unit 30 thus the percussion piston 3 is forcibly guided over the respective stops 33, 34 and the driver 31. During a forward movement of the drive unit 30 (in Fig. 7 down) in the direction of the tool (working direction) push the upper stops 34 the driver 31 with the percussion piston 3 down, the percussion piston should fly freely before hitting the tool or the intermediate striker to harmful repercussions on the drive unit 30 and the driver 31 to avoid. In the subsequent subsequent return movement of the drive unit 30, the lower stops 33 come into contact with the driver 31 and pull the rest of the rebounding piston of the rest of the tool 3 against the working direction. Thereafter, the duty cycle is repeated by the drive unit 30 with the upper stops 34 accelerates the percussion piston 3 again against the tool.

The coupling device is thus not formed by an air spring, but by the longitudinal grooves 32, the stops 33, 34 and the driver 31 in this embodiment. Of course, the structure described is merely illustrative. There are numerous other possibilities for the skilled artisan, as the movement of the drive unit 30 can be transferred to the percussion piston 3.

The piston head 2 of the percussion piston 3 is positively coupled via a piston rod 35 with a pump piston 13. The pump piston 13 is reciprocable in a pumping chamber 14.

Via the intake passage 15a, the air from the environment can flow into the pumping chamber 14 in the manner described above, when the pump piston 13 moves down. During a return movement of the percussion piston 3 with the positively coupled pumping piston 13, the air is discharged from the pumping chamber 14 via the outlet channel 15b to the environment.

The other functions, in particular the stirring of the cooling air flow and the design of the air conveying device including any non-return valves can be realized analogously to the embodiments described above.

Fig. 8 shows a section through a schematic representation of a striking mechanism according to an eighth embodiment of the invention, in which the striking mechanism as in the embodiment of Fig. 7 also not realized as Luftfederschlagwerk. Unlike the in Fig. 7 embodiment shown, however, the pump piston 13 is positively coupled to the drive unit 30, as z. Tie Fig. 1 to 6 is shown. As a coupling device for transmitting the drive movement of the drive unit 30 to the percussion piston 3 but in Fig. 7 used solution shown.

So that no unwanted air spring can form above the piston head 2 of the percussion piston 3, perforations 36 are provided in the drive unit 30. The openings 36 are in Fig. 8 only shown schematically. They should have the largest possible cross-sections, so that they can be flowed through unhindered by the air and form no noticeable air resistance. Of course, other constructions are readily conceivable, with which the drive unit 30 can be connected to the pump piston 13. If this is an arrangement similar to the Fig. 1 to 6 is selected, but in the eighth embodiment of the invention to make sure that actually no air spring is formed between the drive unit 30 and the percussion piston 3.

Claims (20)

1. Hammer drill and/or percussion hammer, having

   - an electrodynamic linear drive (11, 12);

   - a percussion mechanism which comprises a drive element (1; 30), which can be moved in a reciprocating manner by the linear drive (11, 12), a percussion element (3), which can be moved relative to the drive element (1; 30), and a coupling device (7; 31-34) which is effective between the drive element (1; 30) and the percussion element (3) and via which the movement of the drive element (1; 30) can be transmitted to the percussion element (3);
   wherein

   - an air conveyance device is provided which comprises a pump element (13), which can be moved linearly in a reciprocating manner, to generate an air flow;

   - the pump element (13) is coupled to the drive element (1; 30) such that the movement of the drive element (1; 30) can be transmitted to the pump element (13);

   - the air conveyance device comprises a pump chamber (14) and an air channel (15);

   - the pump element (13) can be moved in a reciprocating manner in the pump chamber (14);

   - the pump chamber (14) can be connected to the surrounding area at least intermittently via the air channel (15);

   - the air channel (15) comprises an intake channel (15a) to allow the influx of air from the surrounding area into the pump chamber (14);

   characterised in that the air channel (15) comprises, in addition to the intake channel (15a), an outlet channel (15b) to allow air to flow out of the pump chamber (14) into the surrounding area.
2. Hammer drill and/or percussion hammer as claimed in claim 1, characterised in that the drive element (1) is connected to a rotor (11) of the linear drive.
3. Hammer drill and/or percussion hammer as claimed in claim 1 or 2, characterised in that the drive element (1) supports the rotor (11) or is formed substantially completely by the rotor (11).
4. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 3, characterised in that the coupling device comprises at least one stop which is effective between the drive element (1) and the percussion element (3).
5. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 4, characterised in that the coupling device comprises an elastic element (7) which is effective between the drive element (1) and the percussion element (3) in at least one direction.
6. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 5, characterised in that the drive element (1), the rotor (11) and the pump element (13) form a structural unit, in particular they are connected together in one piece.
7. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 6, characterised in that the movement of the drive element (1) can be transmitted to the pump element (13) via a mechanical, hydraulic or pneumatic coupling.
8. Hammer drill and/or percussion hammer as claimed in claim 7, characterised in that the pump element (13) is disposed in a region of the hammer drill and/or percussion hammer which in terms of oscillation is decoupled from the percussion mechanism.
9. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 8, characterised in that the rotor (11) is substantially cylindrical or hollow-cylindrical.
10. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 8, characterised in that the rotor (11) comprises at least one plate-shaped element (22) which extends in the axial direction.
11. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 10, characterised in that the air channel (15) is disposed in such a manner that it extends along heat-generating structural elements of the hammer drill and/or percussion hammer, in particular along a portion of a stator (12) of the linear drive.
12. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 11, characterised in that a non-return valve (16, 17) is disposed in the intake channel (15a) and/or in the outlet channel (15b).
13. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 12, characterised in that a storage device (18) is in communication with the outlet channel (15b) for the intermediate storage of at least a portion of the air flowing out via the outlet channel (15b).
14. Hammer drill and/or percussion hammer as claimed in claim 13, characterised in that a cross-section of the outlet channel (15b) downstream of the storage device is smaller than a cross-section of the outlet channel (15b) upstream of the storage device (18).
15. Hammer drill and/or percussion hammer as claimed in claim 13 or 14, characterised in that the storage device (18) can be filled during a backward movement of the drive element (1) and can be emptied during a percussion movement.
16. Hammer drill and/or percussion hammer as claimed in any one of claims 13 to 15, characterised in that a non-return valve (17) is disposed in the outlet channel (15b) between the pump chamber (14) and the storage device (18).
17. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 16, characterised in that as seen in the percussion direction the pump element (13) is disposed behind the drive element (1) and the rotor (11) or next to the percussion mechanism.
18. Hammer drill and/or percussion hammer as claimed in any one of claims 1 to 17,
    characterised in that

    - the percussion mechanism is a pneumatic spring percussion mechanism;

    - the drive element is formed as a drive piston (1);

    - the percussion element is formed as a percussion piston (3); and in that

    - the coupling device comprises a pneumatic spring (7) which is formed in a hollow space between the drive piston (1) and the percussion piston (3).
19. Hammer drill and/or percussion hammer as claimed in claim 18, characterised in that a cross-sectional area of the pump element (13) which is effective for generating the air flow is greater than a cross-sectional of the drive piston (1) which acts upon the pneumatic spring (7).
20. Hammer drill and/or percussion hammer as claimed in any one of claims 18 or 19, characterised in that as seen in the percussion direction the drive piston (1) surrounds the percussion piston (3) in front of and behind the percussion piston (3) such that the pneumatic spring (7) is disposed behind the percussion piston (3), and in that in front of the percussion piston (3) a second pneumatic spring (9) can be formed between the drive piston (1) and the percussion piston (3).

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