WO2022175059A1

WO2022175059A1 - Electric working device for selective operation at at least two different supply voltages

Info

Publication number: WO2022175059A1
Application number: PCT/EP2022/052044
Authority: WO
Inventors: Rainer Glauning; Marc-Alexandre Seibert
Original assignee: Robert Bosch Gmbh
Priority date: 2021-02-19
Filing date: 2022-01-28
Publication date: 2022-08-25
Also published as: DE102021201620A1; EP4320710A1

Abstract

The invention relates to an electric working device (10) comprising • a housing (14), • power electronics (36) for converting a first supply voltage (U_H), in particular for mains operation, and at least one second supply voltage (U_L) which differs significantly from the first supply voltage (U_H), in particular for battery operation, into a pulse-width-modulated motor voltage (U_M), • an electric motor (12) which can be supplied with the motor voltage (U_M) and which comprises a rotor (40) and a stator (42), wherein the stator (42) has three stator poles (44), and each stator pole (44^I, 44^II, 44^III) has an integral multiple of stator teeth (46), each of which has a plurality of windings (48) for driving the rotor (40), the type and/or number of windings (48) on the stator teeth (46) being configured such that the electric motor (12) can be operated over three phases (U, V, W) selectively using the first or the at least one second supply voltage (U_H, U_L), • an output part (116), which is driven by the electric motor (12), for converting the drive energy generated by the electric motor (12) into mechanical energy required to use the electric working device (10), and • a switchover device (50) which connects the windings (48) of the electric motor (12) in series and/or in parallel for selective operation at the first or the at least one second supply voltage (U_H, U_L). According to the invention, the switchover device (50) is topologically separated from the output part (116) within the housing (14) such that the switchover device is functionally arranged in front of the electric motor (12) and the output part (116), in particular as part of the power electronics (36).

Description

title

Electrical processing device for optional operation with at least two different supply voltages

description

The invention relates to an electrical processing device for selective operation with a first or at least a second supply voltage according to the preamble of independent claim 1.

State of the art

Battery-powered processing devices, especially hand-held power tools, have increasingly replaced their mains-powered counterparts in recent years, since the battery packs and electric motors have become lighter and more powerful. The so-called electrically commutated (EC) or brushless direct current motors (BLDC) have established themselves here in particular. Despite the light and compact EC motors and the ever more powerful batteries or replaceable battery packs, it is often necessary, especially in the high performance classes, to operate the processing equipment over a longer period of time, so that the batteries or replaceable battery packs are charged relatively frequently and/or charged must be changed. There is therefore a need for so-called hybrid devices with corresponding electric motors that can be operated both by battery and with mains power.

A battery-powered hand tool in the form of a cordless screwdriver is known from EP 3 316453 A1. The hand-held power tool has a brushless electric motor with a stator and a rotor mounted within the stator to rotate relative thereto. The stator comprises three windings, each winding being distributed over two opposite stator poles over the circumference of the stator. The three stator windings can be forthcoming switching means can be operated either in a delta or star connection.

US 2019/0229599 A1 discloses a stationary power tool that can be operated either with a first supply voltage, in particular a mains voltage, or with a second supply voltage, in particular a battery voltage. For this purpose, the power tool has two power output stages, with a first power output stage driving first windings of the electric motor and a second power output stage driving second windings of the electric motor depending on the detected supply voltage for operating an electric motor. The first and second windings differ in particular in their number of turns and/or the wire cross-section. It is provided that the stator teeth of the stator poles of the electric motor either carry the first or the second windings in alternation or that each stator tooth has a first and a second winding. Furthermore, the possibility of switching between a star and a delta connection is also shown, the first windings being permanently connected to form a star connection and the second windings being permanently connected to form a delta circuit.

The object of the invention is to design an electrical processing device for optional operation with at least two different supply voltages in such a way that, in particular, parts of a supply and drive part of the processing device can be manufactured universally, i.e. largely independently of the intended use of the processing device, and if necessary easily and can be exchanged inexpensively.

Advantages of the Invention

The invention is based on an electrical processing device

• a housing,

• Power electronics for converting a first supply voltage, in particular for network operation, and at least one compared to the first supply voltage that is significantly different second supply voltage, in particular for battery operation, into a pulse width modulated motor voltage,

• an electric motor that can be subjected to the motor voltage and has a rotor and a stator, the stator having three stator poles and each stator pole having an integer multiple of stator teeth, each with a plurality of windings for driving the rotor, the windings of the stator teeth having a different type and/or number are designed in such a way that the electric motor can be operated over three phases either with the first or with the at least one second supply voltage,

• an output part driven by the electric motor for converting the drive energy generated by the electric motor into mechanical energy required for using the electrical processing device and

• a switching device which switches the windings of the electric motor in series and/or in parallel for selective operation with the first or the at least one second supply voltage.

To solve the task it is provided that within the housing the switching device is topologically separated from the output part in such a way that it is functionally arranged, in particular as part of the power electronics, in front of the electric motor and the output part. In this way, parts of a supply and drive part of the electrical processing device, in particular the electric motor and the associated switching device, can be produced universally and can therefore be used in different processing devices. In addition, the topological separation between the output part and the supply and drive part results in the possibility of effective vibration decoupling between these two parts or their components.

In the context of the invention, “electrical processing devices” should be understood to mean, among other things, battery-operated and/or mains-operated machine tools for processing workpieces using an electrically driven insert tool. The electrical processing device can be designed both as a hand machine tool and as a stationary machine tool. Typical machine tools in this context are handheld or stationary drills, screwdrivers, percussion drills, planers, angle grinders, Orbital sanders, polishing machines or the like. However, garden and construction equipment driven by an electric motor such as lawnmowers, grass trimmers, pruning saws, motor and trench cutters, blowers, robot breaker and excavator or the like can also be used as electrical processing devices. Furthermore, the invention is on three-phase electric motors of household appliances, such as vacuum cleaners, mixers, etc. applicable. The term electrical processing device can also be understood to mean road and rail vehicles driven by electric motors, as well as aircraft and ships or boats.

“Operation with a first supply voltage” or “mains operation” should be understood to mean, in particular, operation with an alternating current (AC) in the range from approx. 110 to 240 V. Significantly higher AC voltages of several 1000 V can also be used for industrial robots, road and rail vehicles, aircraft and ships. The typical AC voltages are primarily dependent on the country-specific values and the intended use. “Operation with a second supply voltage that is significantly different from the first supply voltage” or “battery operation” should be understood to mean, in particular, operation with a direct voltage (DC) in the range from 3.6 to 180 V. But even here, significantly higher battery voltages of several 100 V can be considered for vehicles, airplanes and ships. The DC voltage values are based primarily on the typical cell voltages of lithium ion cells. However, other cell voltages are also possible, for example for pouch cells and/or cells with a different electrochemical composition. It should also be noted that the term "significantly different supply voltage" can refer not only to the amplitude but also to the frequency of the supply voltage. For battery operation, both exchangeable battery packs and permanently integrated batteries with any number of battery cells can be considered. The exchangeable battery packs can be detachably connected to the electrical processing device in a non-positive and/or positive manner via suitably designed electromechanical interfaces. A "releasable connection" is to be understood in particular as a connection that can be released and produced without tools, ie by hand. Since the person skilled in the art is sufficiently familiar with such rechargeable batteries and rechargeable battery packs as well as the corresponding electromechanical interfaces, this should not be discussed any further be addressed in detail. The terms rechargeable battery, rechargeable battery pack and exchangeable rechargeable battery pack are to be understood below as synonyms, since they have the same meaning for the invention.

In a further embodiment of the invention, it is provided that the switching device is designed in such a way that it can additionally connect the phases of the electric motor in a star connection or in a delta connection. The optional connection of the phases as a star or delta connection results, on the one hand, in connection with the star connection, in a significant reduction in the power requirement by a factor of 1.73 per phase or stator pole, which is particularly advantageous when the electric motor starts up while high currents and power can be used in the delta connection.

It is also provided that the power electronics have first power electronics, in particular AC electronics, for operation with the first supply voltage and at least one second power electronics, in particular DC electronics, for operation with the at least one second supply voltage, the first and the at least one second power electronics are galvanically isolated from each other. Due to the galvanic isolation of the two power electronics, voltage flashovers between them can be avoided with particular advantage. This ensures that an operator is protected from dangerous voltages on any exposed electrical contacts of the connection interfaces for an exchangeable battery pack or a mains plug on the electrical processing device. In addition, the electrical processing device itself can be protected against short circuits on these exposed contacts.

In a development of the invention, it is provided that the electric motor has a motor shaft and that the switching device is reversibly attached to a side of the electric motor that faces away from the motor shaft. Thus, the switching device can be very easily plugged onto the electric motor by the manufacturer and removed from it again if necessary, especially in the case of service. The reversible fastening of the switchover device on the electric motor takes place in such a way that contact sockets of the switchover device engage electromechanically with contact pins of an adapter plate connected to the stator of the electric motor. The switching device has switching elements for parallel or series connection of the windings and star or Delta connection of the phases of the electric motor, which are electrically connected to the contact sockets. In an analogous manner, the contact pins of the adapter plate are electrically connected to the windings of the electric motor. This allows a very universal production of the switching device for electric motors un ferent performance classes and different types of winding.

The assembly consisting of the electric motor, the adapter plate and the switching device is constructed along an axis defined by the motor shaft. This enables a particularly compact electric motor that is easy to replace, in particular when the switching device is designed as a modular assembly of the electric motor.

In an alternative embodiment, the switching device is arranged in the housing of the electrical processing device on a side facing away from the motor shaft of the electric motor. In this way, the electrical connection between the electric motor and the switching device can be kept short, even if there is a local separation within the housing, in order to achieve improved vibration decoupling between the two components. Depending on the arrangement of the electric motor and the switching device, it can be advantageous if the switching device is arranged at a defined angle, in particular not equal to 0° or 180°, to the electric motor in the housing.

The switching device and any other electrical components for rectifying, voltage conversion, filtering and/or end interference of the first and the at least one second supply voltage and for controlling the electric motor together form power electronics. The term "power electronics" should therefore be understood to mean the part of the electronics that controls the electric motor, which primarily absorbs the winding currents. The power electronics therefore differ from the control and regulation electronics that actuate them. As a rule, the power electronics are installed in the electrical processing device and can thus be specifically adapted to the respective requirements of the device. In this way, over- or under-dimensioning of the power electronics can be avoided. Processing devices with a high energy requirement (e.g. angle grinders, large rotary and demolition hammers, professional kitchen appliances, etc.) receive a correspondingly powerful power elec- ronik, while in the case of processing devices with a rather low energy requirement (e.g. screwdrivers, blender, etc.) cost-effective and significantly less resilient power electronics can be used. In the case of battery-powered devices in particular, complex power electronics, for example in the form of a DC/DC converter with a large ratio between the input voltage and the output voltage, are then no longer required, resulting in a compact overall drive train.

The possibility of being able to do without individual components in the electronic processing device, depending on requirements, results in a modular overall concept, in particular from a power bridge, switching device and electric motor for the following applications:

• Multi-voltage devices for hybrid operation (battery and/or mains operation): the electrical processing device can optionally be used for mains operation with several first supply voltages or an intermediate voltage and at least one first supply voltage of e.g. 120 V and 230 V and/or for battery operation several second supply voltages of e.g. 18 V, 36 V or 72 V.

• Multi-voltage devices for mains operation: the electrical processing device can be designed for mains operation with several first supply voltages or an intermediate voltage and at least one first supply voltage of 120 V and 230 V, for example. This means that the DC part of the power electronics can be dispensed with.

• Multi-voltage devices for battery operation: the electrical processing device can be designed for battery operation with several second supply voltages of e.g. 18 V, 36 V or 72 V, so that the AC part of the power electronics can be dispensed with.

• Dual-voltage devices for hybrid operation (battery and/or mains operation): the electrical processing device can be designed either for mains operation with a first supply voltage of, for example, 230 V or for battery operation with a second supply voltage of, for example, 36 V. This enables the use of simpler power electronics for a reduced number of series or parallel connections of the windings per stator pole. • Single voltage devices for mains operation, eg 230 V.

• Single voltage devices for battery operation, e.g. 36 V.

Further options for generating the request signal for switching between the operating modes of the electric motor are described below in the exemplary embodiments.

exemplary embodiments

drawing

The invention is explained below by way of example with reference to FIGS. 1 to 22, with the same reference symbols in the figures indicating the same components with the same function.

Show it

Fig. 1: a schematic representation of a first exemplary embodiment of an electrical processing device according to the invention in the form of a hand-held impact wrench,

Fig. 2 shows a schematic representation of a first exemplary embodiment of an electric motor according to the invention with a stator tooth carrying four windings,

3: a schematic representation of a second exemplary embodiment of the electric motor according to the invention with a stator tooth carrying two windings,

4: a circuit diagram of an embodiment of the electric motor according to the invention for a parallel connection of the four windings of a stator pole and a delta connection of the three phases of the electric motor, 5 shows a circuit diagram of an embodiment of the electric motor according to the invention for a series connection of the four windings of a stator pole and a star connection of the three phases of the electric motor,

6: a block diagram of an exemplary embodiment of the switching device according to the invention for the electric motor according to FIGS. 3 to 5,

Fig. 7: an exploded drawing of the electric motor according to the invention with an inventive electromechanical switching device,

Fig. 8: Exemplary embodiments of the electromechanical switching device according to the invention with a rotatable carrier,

Fig. 9: Exemplary embodiments of the electromechanical switchover device according to the invention with a displaceably designed carrier,

Fig. 10: further exemplary embodiments for a displaceable carrier of the electromechanical switching device according to the invention,

Fig. 11: another embodiment of a rotatable support of the electromechanical switching device according to the invention,

12: a schematic block diagram for the electrical processing device according to the invention,

13: a schematic representation of a second exemplary embodiment of the electrical processing device according to the invention in the form of a demolition hammer, 14: a schematic representation of a third exemplary embodiment of the electrical processing device according to the invention in the form of a demolition hammer,

15: Exemplary embodiments for a vibration-decoupled mounting of the switching device according to the invention with pressure-loaded damping elements in the form of rubber dampers,

16: Exemplary embodiments for a vibration-decoupled mounting of the switching device according to the invention with damping elements under tensile load in the form of rubber dampers,

17: Exemplary embodiments for a vibration-decoupled mounting of the switching device according to the invention with pressure-loaded damping elements in the form of spring dampers,

18: Exemplary embodiments for a vibration-decoupled mounting of the switching device according to the invention with damping elements under tension in the form of spring dampers,

19: a schematic representation of a fourth exemplary embodiment of the electrical processing device according to the invention in the form of a hammer drill,

20: a schematic representation of a fifth exemplary embodiment of the electrical processing device according to the invention in the form of an angle grinder,

Fig. 21: a schematic representation of a sixth game Ausführungsbei the electrical processing device according to the invention in the form of an industrial vacuum cleaner and 22: A schematic representation of a seventh embodiment of the game of the electrical processing device according to the invention in the form of a lawnmower.

Description of the exemplary embodiments

Fig. 1 shows an example of an electrical processing device 10 designed as a rotary impact wrench with a three-phase electric motor 12. The rotary impact wrench has a housing 14 with a handle 16 and a tool holder 18 and can be optionally powered mechanically and electrically via appropriately designed electromechanical interfaces for mains-independent power supply 19 can be releasably connected to a battery pack 20 in a non-positive and/or positive manner or, for mains-dependent power supply, via a mains cable 22 to a mains supply, which is not shown but is known to the person skilled in the art. In the present example, the power grid has a first supply voltage UH of 230 V AC (50 Hz) and the battery pack 20 has a second supply voltage UL of 36 V DC that is significantly different from the first supply voltage. With particular advantage, the invention can also be applied to electrical processing equipment with rechargeable batteries and mains supplies of other voltage and power classes. It should also be pointed out that the invention is neither limited to impact wrenches nor to hand-held power tools in general, but - as already mentioned - can be used with different mains-independent and/or mains-dependent electrical processing devices.

The electric motor 12 , which is supplied with power by the battery pack 20 or via the mains cable 22 , together with a gear 24 and a percussion mechanism 26 are arranged in the housing 14 , for example. The electric motor 12 can be actuated via a main switch 28, ie it can be switched on and off and its speed and/or torque can be changed. The electric motor 12 and the gear 24 can alternatively also be arranged in a common sub-housing or in separate motor and gear housings, which in turn are accommodated in the housin se 14 . The percussion mechanism 26 is driven by a motor shaft 30 of the electric motor 12 and is designed, for example, as a rotary or rotary percussion mechanism that generates abrupt angular momentum with high intensity. testifies and transfers to the tool holder 18, the measure for exchangeable on an insert tool 32 is used. Since the tool holder 18 and the insert tool 32 are of no significance as such for the invention, they will not be discussed in any more detail here. The possible configurations are well known to those skilled in the art.

The electric motor 12 is acted upon by a power bridge 34 of power electronics 36 with a pulse width modulated motor voltage UM. For this purpose, the power bridge 34 has various power transistors (e.g., bipolar transistors, field effect transistors, IGBT, or the like), which, depending on the design of the electric motor 12, can be connected, for example, as an H bridge, B6 bridge, or the like. A control or regulating electronics 38 controls the individual power transistors of the power bridge 34 according to a predetermined by the main scarf ter 28 signal for generating the PWM voltage UM. Since the various possible configurations of the power bridge 34 and the control or regulating electronics 38 are known to a person skilled in the art, they will not be discussed in any more detail. The control or regulation electronics can, for example, be in the form of a microcontroller, DSP, ASIC or the like.

With reference to Figure 2, the three-phase electric motor 12 includes an inner rotor 40 and an outer stator 42 with three stator poles 44. Each stator pole 44 ¹ , 44", 44 ^m has in the exemplary embodiment shown M=2 stator teeth 46, which extend over the Distribute the circumference of the stator 42 diametrically opposite each other. Each stator tooth 46 ¹ , 46'' in turn has a plurality N=4 windings 48 for driving the rotor 40. The individual windings 48′, 48″, 48 ^m , 48 ^IV can differ in their type, ie in the number of turns, in their cross section and/or in their material. However, they can also be designed in the same way. Around the stator 42 and thus to cause the rotor 40 to rotate, a current I _n flows through the N=4 windings 48 of the corresponding stator tooth 46 ¹ , 46" of the stator pole 44 ¹ , 44", 44 ^m The magnetic fields B _n generated are proportional to the currents I _n and the number of turns of the individual windings 48. Thus, a winding with a few turns and a large cross section through which a high current flows can generate the same magnetic field as a winding with many turns and small cross-section, through which a significantly less current flows. The individual magnetic fields B _n in the stator teeth 46 ¹ , 46" finally add up to form a total magnetic field B=S _h =i ^N B _n which drives the rotor 40.

Returning to FIG. 1, the electrical processing device 10 can be operated by an operator either with the first supply voltage UH of 230 V AC (50 Hz) or with the second supply voltage UL of 36 V DC, which is significantly different than the first supply voltage. Electric motor 12 is switched over between operation with the first supply voltage UH and operation with the second supply voltage UL in such a way that a switching device 50 in power electronics 36 switches the N = 4 windings 48 of a stator tooth 46 of electric motor 12 for operation with the first Supply voltage UH or the second supply voltage UL in series and / or parallel. With M * N series-connected identical windings 48 of a stator pole 44 ¹ , 44", 44 ^m , the electric motor 12 can thus be operated with (M * N) times the supply voltage compared to M * N parallel-connected windings 48, while in parallel operation a (M*N) times the total current can flow compared to the series circuit. The switching device 50 can be designed electronically or electromechanically. This will be discussed in more detail below in connection with FIGS.

Switching between the operating modes of the electric motor 12 can take place either manually by means of a mode switch 52 that can be actuated by the operator and/or automatically by means of a sensor system 54 of the electrical processing device 10 . The control or regulating electronics 38 of the electrical processing device 10 can evaluate a request signal from the operating mode switch 52 or the sensor system 54 for switching between the operating modes of the electric motor 12 and control the switching device 50 for parallel and/or series connection of the corresponding windings 48. If the switching device 50 is constructed electromechanically, it is alternatively also conceivable that the operating mode switch 52 is mechanically coupled to the switching device 50 and adjusts it directly. The request signal can be generated, for example, via a cover flap 56 for a mains connection 58 of the electrical processing device 10 . This is closed during battery operation and open during mains operation as a result of an inserted mains plug 60 of the mains cable 22 . The position of the cover flap 56 is detected by means of the sensors 54, for example in the form of a reed contact or microswitch, and the corresponding request signal for operation with the first supply voltage UH is sent to the control or regulating electronics 38. Despite the inserted battery pack 20, operation with the first supply voltage UH has priority over operation with the second supply voltage UL. Alternatively, it is also conceivable that the power supply with the highest performance has priority. For this purpose, the power electronics 36 is divided into a first power electronics 36H for operation with the first supply voltage UH and in at least one second power electronics 36L for operation with the at least one second supply voltage UL. In a particularly advantageous manner, the two electronic power units 36H, 36L are electrically isolated from one another. This will be discussed in more detail later with reference to FIG. In order to protect the operator from voltage surges from exposed and live electrical contacts on the one hand and the electrical processing device 10 from short circuits caused by exposed contacts on the other, it is also provided that in the case of mains operation the electrical contacts of the unused electromechanical interface 19 for the Battery pack 20 and in the case of Ak kubetriebs the electrical contacts of the unused mains connection 58 of the electrical processing device 10 are electrically isolated. This galvanic isolation can be effected by switching elements of the switching device 50 (not shown in detail) which, in the case of an electromechanical design of the switching device 50, have corresponding air and creepage distances. Alternatively or additionally, it is also possible to cover the unused connections 19 and 58 mechanically. In the case of battery operation, for example, the cover flap 56 of the mains connection 58 can be locked electromechanically or use of the electrical working device 10 can only be released when the cover flap 56 is locked. Correspondingly, locking the electromechanical interface 19 for the battery pack 20 is conceivable, although it could also suffice here just the individual cover electrical contacts of the interface 19, for example, with sliding plastic caps or the like.

The generation of the request signal or the detection of the desired operating mode can be implemented in various other ways. For example, it could also be done using a human-machine interface (HMI) in the form of a control panel or a touch display on the electrical processing device 10, which the operator has to operate accordingly. Such an HMI can also serve as a display for the operating mode set using the switching device 50 . Of course, the switching device 50 itself can also have a corresponding display, for example in the form of an LED or the like. In addition or as an alternative, control via an app via a wireless interface via WLAN, Bluetooth or the like on the electrical processing device 10 would be conceivable. A switch or button on the power cord 22 would also be possible. Other solutions for switching the operating mode of the electric motor 12 could be an RFID tag on the mains cable 22, by directly sensing the supply voltage in the electrical processing device 10, e.g. using a step-up and/or step-down converter, or by coding in the battery pack 20 be realized. In the event that both the mains cable 22 and the battery pack 20 with the electrical processing device 10 is connected, the power supply with the highest efficiency (very powerful battery packs sometimes have a higher current delivery capacity than a supply from the mains) or basically the mains voltage have priority. A corresponding setting of the priorities can be made in an app, for example. Furthermore, it is also possible to switch automatically between the two operating modes if, for example, the mains supply breaks off when the battery pack 20 is plugged in or, conversely, a battery pack 20 that is plugged in has been largely discharged.

Safety features are also conceivable, such as an automatic or manual switchover to mains operation when the electrical processing device 10 is being transported with one or more battery packs 20 inserted. an automatic conversion Switching takes place when not in use for a longer period of time by a motion or acceleration sensor integrated in the electrical processing unit 10 . If the electrical processing device 10 is transported with several battery packs 20 (e.g. 2 x 18 V) connected in series, galvanic isolation of the individual battery packs 20 is also conceivable in order to comply with the corresponding transport standards, since each battery pack 20 is then regarded as an individual battery pack becomes. An automatic switchover from battery to mains operation can be provided if there is a sudden temperature rise in one of the inserted battery packs 20, particularly when the electrical processing device 10 is being supplied by several battery packs 20 connected in series. The same is conceivable if there is an abrupt voltage drop in the at least one second supply voltage UL, or if it is outside a permissible voltage range.

Since the switching device 50, with reference to Figure 2, switches the N = 4 windings 48 of a stator tooth 46 ¹ , 46" in series during operation with the first supply voltage UH or during mains operation, flows through the M * N = 8 windings 48 of a stator pole 44 ¹ , 44", 44 ^m with the same design, the same current li = b = ... = IM _N . There is an overall low power requirement and the following applies to the overall magnetic field: B = Bi + B2 ... + BM _N = M * N * Bi. When operated with the second supply voltage UL or when operated with a rechargeable battery, the parallel connection results in the M * N = 8 windings 48 an addition of their individual currents li + I2 + ... + IM _N . If each of the 8 windings 48 is of the same type, this results in a total current I=8*li, which results in the total magnetic field being B=8*Bi again. Consequently, the electric motor 12 has essentially the same maximum power in both operating modes. Depending on the level of the first and the second supply voltage UH, UL, a different number of the M * N windings 48 of a stator pole 44 ¹ , 44", 44 ^m can be connected in parallel and/or in series with essentially the same maximum power of the electric motor 12 . This then enables a so-called multi-voltage operation of the electric motor 12 according to the invention or a multi-voltage device for mains, battery or hybrid operation, ie for example battery operation with 12, 18 or 36 and/or mains operation with 120 or 230 V without having to adapt the number of stator teeth 46 in the electric motor 12. From this, for example, the following number M*N of windings 48 per phase U, V, W or stator pole 44 ¹ , 44", 44 ^m , in which case the voltage ratio of the rectified, first supply voltage UH and the second supply voltage UL can be rounded off, since the electric motor 12 generally tolerates smaller supply voltage differences:

• U _H = 230 V AC (approx. 300 V DC), _UL = 12 V DC windings 48

• U _H = 230 V AC (approx. 300 V DC), _UL = 18 V DC (max. approx. 20 V) windings 48

• U _H = 230 V AC (approx. 300 V DC), _UL = 36 V DC (max. approx. 40 V) windings 48

• U _H = 120 V AC (approx. 150 V DC), _UL = 12 V DC windings 48

• U _H = 120 V AC (approx. 150 V DC), _UL = 18 V DC (max. approx. 20 V) windings 48

• U _H = 120 V AC (approx. 150 V DC), _UL = 36 V DC (max. approx. 40 V) windings 48

For the best possible concentricity and correspondingly optimized symmetry properties of the electric motor 12, it is expedient to distribute the number of windings 48 evenly over the M stator teeth 46 of the stator poles 44. If, for example, each stator pole 44 ¹ , 44", 44 ^m M = 2 stator teeth 46, the number of windings 48 per stator pole 44 ¹ , 44", 44 ^m should be an integer divisible by M, e.g. in the case of 2 stator teeth 46 per stator pole 44 ¹ , 44", 44 ^m 26 instead of 25 and 16 instead of 15 windings 48.

For operation with the second supply voltage UL, it can be additionally provided, for example, that the switching device 50 connects the windings 48 of a stator pole 44 ¹ , 44", 44 ^m in parallel in such a way that, in the case of a small maximum current, a smaller number J<M*N windings 48 is connected in parallel than in the case of a maximum current that is significantly higher than the small maximum current. Accordingly, for operation with the first supply voltage UH J <M*N, windings 48 can be connected in series in order to be able to operate the electric motor 12 with different mains voltages. to. It is also possible for switching device 50 to switch at least part of the M * N windings 48 of a stator pole 44 ¹ , 44", 44 ^m in parallel and in series for operation with at least one intermediate voltage Uz, with the intermediate voltage Uz between the at least a first supply voltage UH and the at least one second supply voltage UL.

FIG. 3 shows a further embodiment of the electric motor 12 according to the invention, in which the switchover between operation with the first supply voltage UH and operation with the at least one second supply voltage UL takes place in such a way that the switching device 50 is designed for operation with the first supply voltage UH a first winding 48 ¹ of a stator tooth 46", in particular a winding 48 with a large number of turns and a small cross section, and for operation with the at least one second supply voltage UL a second winding 48" of the stator tooth 46", in particular a winding 48 with a small number of turns and a large cross section. In this case, the second winding 48" is wound over the first winding 48 ¹ in a particularly advantageous manner. This enables a dual-voltage device for hybrid operation to be implemented in a simple and cost-effective manner with a "high-voltage winding" 48 ¹ , which is designed, for example, for mains operation with typically 300V DC, and a "low-voltage winding" 48 ", which is designed for battery operation with 36 V. Here, too, the windings 48 can be designed in such a way that the electric motor 12 can be operated in both operating modes with essentially the same maximum power. Likewise, more than two windings 48 per stator tooth 46 ¹ , 46" and fewer or more than two stator teeth 46 per stator pole 44 ¹ , 44", 44 ^m are conceivable. The invention can also be used for very small or high-speed electric motors 12 with only one stator tooth 46 per stator pole 44 ¹ , 44", 44 ^m (simple three-phase EC motors) are applied.

FIG. 4 shows the connection of the three phases U, V, W of the electric motor 12 controlled by the power bridge 34 by PWM signal with windings 48 of the three stator poles 44 connected in parallel in a delta connection. The two windings 48 of the stator teeth 46 of each stator pole 44 ¹ , 44", 44 ^m (cf. also FIG. 3) are combined as a group. In contrast to FIG each in Series-connected windings 48 of the three stator poles 44 of the electric motor 12 are shown. Due to the possibility of being able to operate the electric motor 12 not only with parallel or series-connected windings 48, but also with phases U, V, W connected in a delta or star connection, a very universal use of the electrical processing device 10 is of little equal Voltages up to high AC voltages in connection with an easy to interpret and inexpensive power electronics 36 or 50 Schaltvor device possible. Furthermore, the use of all windings 48 of the electric motor 12 for the different operating modes allows a reduced weight of the electric motor 12 with a simultaneous increase in effectiveness. The optional connection of the phases U, V, W as a star or delta connection results in a significant reduction of the current requirement by a factor of 1.73 (root 3) per phase U, V, W or Stator pole 44 ¹ , 44", 44 ^m , which is particularly advantageous when the electric motor 12 starts up, while high currents and outputs can be used in the delta connection. Taking the above explanations into account, the following reduced number M * Determine N of windings 48 per phase U, V, W or stator pole 44 ¹ , 44", 44 ^m :

• U _H = 230 V AC (approx. 300 V DC), _UL = 12 V DC windings 48

• U _H = 120 V AC (approx. 150 V DC), _UL = 12 V DC windings 48

For operation with the first supply voltage UH, it is expedient, in addition to the star connection, to connect all windings 48 of a stator pole 44 ¹ , 44", 44 ^m in series. In addition or as an alternative, it can be expedient for operation with the second supply voltage UL to connect all windings 48 of a stator pole 44 ¹ , 44", 44 ^m in parallel in addition to the delta connection. Since all windings 48 of the stator 42 are always supplied with current at the same time, the electric motor 12 can in this way be used optimally from the installation space and a minimum number of windings with a star connection of the phases U, V, W for the first supply voltage UH and with a delta connection of the phases U, V, W are operated for the second supply voltage UL. With particular advantage, the electric motor 12 cannot be switched over to a star connection in battery operation with the at least one second supply voltage UL, but can only be operated with phases U, V, W connected in a delta. Thus, all windings 48 are supplied with a lower motor voltage UM than in mains operation with the first supply voltage UH and the electric motor 12 runs with reduced power. This then allows, for example, a gentle start-up of the electric motor 12 of an electrical processing device 10 designed as a drill hammer in order to generate the most effective possible impact energy. Likewise, this procedure can also enable a warm-up, reduced operation for replaceable battery packs 20 with reduced performance (eg as a result of aging) or reduced power consumption when idling. Provision can also be made for the electric motor 12 to be operable with essentially the same maximum power when switching over the windings 48 between operation with the first supply voltage UH and the second supply voltage UL both with phases U, V, W connected in a star connection and with phases connected in a delta connection is.

In connection with the possibility of a soft start and a correspondingly high number N of windings 48 per stator tooth 46 ¹ , 46 ", of which not all windings 48 are then permanently energized, a so-called booster operation can also be implemented in which the switching device 50, all windings 48 of the stator teeth 46 are briefly energized for operation with the at least one first supply voltage UH and for operation with the at least one second supply voltage UL, in order to achieve significantly higher motor power to cover power peaks -Operation is additionally or alternatively according to the exemplary embodiment according to FIG. 2 also in pure battery operation with the at least one second supply supply voltage UL possible. The windings 48 of a stator tooth 46 ¹ , 46" can, depending on the situation, depending on the state of charge of the battery or battery pack 20 - when the state of charge is low, the available second supply voltage UL is also low - and the load - a higher load current I causes a higher voltage drop and thus a higher second supply voltage UL - can be connected in series and/or in parallel very quickly (almost in real time) by means of an electronically designed switching device 50. With a high load and a low state of charge of the rechargeable battery or rechargeable battery pack 20, a winding mix would then be used with a higher proportion of parallel connections and with a small load and a high state of charge with a lower proportion of parallel connections is advantageous. Booster operation can also be implemented in such a way that at least one of the windings 48 of a stator tooth 46 ¹ , 46" is additionally energized only for this purpose and otherwise for the battery and Mains operation in the normal power range remains unenergized.

Figure 6 shows a first embodiment of the switching device 50 according to the invention for the electric motor 12 with three phases U, V, W or stator poles 44, analogous to Figures 3 to 5, each stator pole 44 ¹ , 44", 44 ^m M = 2 stator teeth 46 each having N=2 windings 48. Each winding 48 ¹ , 48″ of the electric motor 12 is connected to the switching device 50 via two electrical contact points 62 in each case. In the embodiment shown, a total of 3*8=24 contact points 62 between the three-phase electric motor 12 and the switching device 50 are required. For the sake of clarity, only the phase U or the stator pole 44 ¹ within a schematic box 64 ¹ was shown in detail in FIG. The two remaining phases V and W or stator poles 44", 44 ^m are configured accordingly and are therefore only shown as empty boxes 64" and 64 ^m . The electrical contact points 62 between the electric motor 12 and the switching device 50 can be designed as plug connections, crimp connections, screw connections, soldered connections or welded connections (cf. FIG. 7).

For each phase U, V, W or stator pole 44 ¹ , 44", 44 ^m , switching device 50 has a plurality of first switching elements 66 for series connection of windings 48 of stator teeth 46 and a plurality of second switching elements 68 for parallel connection of windings 48 of stator teeth 46 on. There are for everyone Stator pole 44 ¹ , 44", 44 ^m each with M stator teeth 46 and N windings 48 per stator tooth 46 ¹ , 46" for series connection and/or for parallel connection of the total of M * N stator windings 48 M * N - 1 first switching elements 66 and M * (2N - 1) second switching elements 68 are provided. In a three-phase stator 42 with three stator poles 44, M=2 stator teeth 46 per stator pole 44 ¹ , 44", 44 ^m and N=2 windings 48 per stator tooth 46 ¹ , 46" result in this way per stator pole 44 ¹ , 44" , 44 ^m 2 * 2 - 1 = 3 first switching elements 66 and 2 * (4 - 1) = 6 second switching elements 68. In total, the switching device 50 therefore has 3 * (3 + 6) = 27 first and second switching elements 66, 68 For the series connection of the windings 48, the first switching elements 66 of the switching device 50 are closed and the second switching elements 68 are opened, while for the parallel connection of the windings 48 in the reverse manner the first switching elements 66 are opened and the second switching elements 68 are closed.

In the exemplary embodiment shown, the windings 48 are connected in series.

In order to be able to additionally connect the phases U, V, W of the electric motor 12 or its stator poles 44 in a star or delta connection, there is also a third switching element 70 and a fourth switching element for each stator pole 44 ¹ , 44", 44 ^m 72. The third switching elements 70 are closed and the fourth switching elements 72 are opened for the star connection of the phases U, V, W, while the third switching elements 70 are opened and the fourth switching elements 72 are closed for the delta connection of the phases U, V, W In the exemplary embodiment shown, in addition to the series connection of the windings 48, there is also a delta connection, ie a further switching variant of the invention compared to FIGS. 4 and 5. For a three-phase electric motor 12 with M=2 stator teeth 46 per stator pole 44 ¹ , 44". 44 ^m and N=2 windings 48 per stator tooth 46 ¹ , 46″ result in a total of 27+6=33 first, second, third and fourth switching elements 66, 68, 70, 72 for the Switching device 50. Without the additional switching option from a delta to a star connection, a factor of 1.73 times as many windings 48 would be necessary according to the above statements, i.e. in the present example N=4 instead of 2 windings 48 per stator tooth 46 ¹ , 46". Thus, instead of the 33 first, second, third and fourth switching elements 66, 68, 70, 72, then a total of 3 * ((M * N - 1) + M * (2N - 1)) = 63 first and second switching elements 66, 68 for the To switching device 50 required, the third and fourth switching elements 70, 72 then accounted for. The additional possibility of switching between a star and a delta connection accordingly leads to a significant reduction in the required switching elements of the switching device 50 and thus also to further savings in installation space, weight and costs.

To activate a series connection of all windings 48 of a stator pole 44 ¹ , 44", 44 ^m in connection with a star connection of the phases U, V, W according to FIG. 5, all first and third switching elements 66, 72 are then closed and all second and fourth switching elements 68, 72 are opened. To activate a parallel connection of all windings 48 of a stator pole 44 ¹ , 44", 44 ^m in combination with a delta connection of the phases U, V, W according to FIG all first and third switching elements 66, 70 open. This can be done simultaneously or with particular advantage to avoid short circuits with a dead time T of a few nanoseconds up to a few seconds between the switching processes of the first and second switching elements 66, 68 or third and fourth switching elements 70, 72.

In order to be able to operate the electric motor 12 in countries with slightly different first supply voltages UH (e.g. Japan, Australia, etc.), a switchable load 74 is provided for each stator pole 44 ¹ , 44", 44 ^m in the case of star connection. This is connected between the fourth switching element 72 and a ground potential GND of the switching device 50 in such a way that it can only act when the fourth switching element 72 of the switching device 50 is closed The load 74 can be deactivated and activated by opening the further switching element 76. With an activated star connection and load 74, it is thus possible in a very simple manner to implement mains operation with 240 V instead of 230 V or with 120 V instead of 110 V. A detection of the respective first supply voltage UH can, for example, via a corresponding mechanical or electrical coding, an RFID tag or the like on the power cord 22 suc conditions. switch 52 or an HMI of the electrical processing device 10 or, in contrast, a fixed specification that can only be changed by the manufacturer.

In a further specific embodiment, the switching device 50 has at least one additional switching element (not shown) for switching over two position and/or speed sensors 78H, 78i_ for the rotor 40 of the electric motor 12 depending on the operation of the electric motor 12 with the first supply voltage UH or with the at least one second supply voltage UL (cf. FIG. 2). It is thus possible to adapt the position and/or rotational speed sensors 78H, 78L in a particularly simple manner to the control or regulating electronics 38 or the power electronics 36H, 36L controlled by them for the correct operation of the electric motor 12. This is necessary because there are typically different sensor positions of the individual sensors for the power electronics 36H, 36L for the first and the at least one second supply voltage UH, UL. As a rule, the three Hall sensors of the position and/or speed sensors 78H for the power electronics 36H are distributed differently over the circumference of the rotor 40 than the three Hall sensors of the position and/or speed sensors 78L for the power electronics 36L. It is also conceivable to use one of the three Hall sensors of the position and/or speed sensors 78H, 78L jointly for the power electronics 36H, 36L, so that a total of only five Hall sensors are required. It is also possible to use the same three Hall sensors for both power electronics 36H, 36L. However, in this case too, switching by means of switching device 50 is advantageous for safe operation of the respective power electronics 36H, 36L. The position and/or speed sensors 78H, 78L are preferably switched over when the electric motor 12 is not in operation, e.g. to secure the clearance or creepage distances between the mains and battery supply or to avoid EMC interference.

All switching elements of the switching device 50 can be designed as semiconductor switches, in particular as MOSFETs, field effect transistors, IGBT, bipolar transistors, or the like. Relays are also conceivable. Depending on the load capacity and switching speed requirements, mixed forms can also be considered, in which, for example, the first and second Switching elements 66, 68 are designed as semiconductor switches and the third and fourth switching elements 70, 72 and the other switching elements 76 as relays.

As already mentioned above, switching over, in particular of the first, second, third and fourth switching elements 66, 68, 70, 72 of the switching device 50, takes place by means of the control or regulating electronics 38 integrated in the electrical processing device 10, depending on the operating mode switch 52 or From the sensor system 54. At the same time, the control or regulating electronics 38, depending on the main switch 28, activate the power bridge 34 to apply the PWM voltage UM to the windings 48 of the individual phases U, V, W. The switching device 50 is therefore located between the power bridge 34 and the electric motor 12 in terms of circuitry. As will be explained below in connection with FIGS. 7 to 11, the switching device 50 can alternatively also be designed electromechanically with corresponding switching elements designed as switching contacts. A hybrid of semiconductor switches and electromechanical switching contacts is also conceivable. For example, the first and second switching elements 66, 68 required for series and/or parallel switching of the windings 48 and the switching elements required for the position and/or speed sensors 78 can be configured as electromechanical switching contacts and those for the star or delta connection of the Phases U, V, W necessary third and fourth Schaltelemen te 70, 72 and necessary for the country-specific network adaptation wide ren switching elements 76 can be designed as semiconductor switches.

FIG. 7 shows an exploded drawing of the electric motor 12 according to the invention with the rotor 40, the stator 42, an adapter ring 80 on the stator side and the electromechanically designed switching device 50 according to the invention. In order to enable the most compact possible electric motor 12 with simple interchangeability, the switching device 50 is designed as a modular assembly of the electric motor 12, which is constructed along an axis defined by the motor shaft 30 of the electric motor 12. The rotor 40 has a plurality of permanent magnets 82 which are rotatably connected to the motor shaft 30 . Also non-rotatably connected to the motor shaft 30 is a fan 84 for cooling the electric motor 12 and, if applicable, the power electronics 36 of the electrical processing device 10. The rotor 40 or the motor shaft 30 are mounted in the stator 42 by means of a bearing 86, which can be formed, for example, as a ball or roller bearing. The stator 42 in turn has the windings 48 distributed over its inner circumference on the stator teeth 46 (cf. also FIGS. 2 and 3 in this regard). The stator 42 is surrounded by a pole pot 88 designed as a laminated core.

The switching elements 66, 68, 70, 72, 76 of the switching device 50 are connected to the windings 48 of the stator poles by means of the electrical contact points 62 formed on the adapter ring 80 as contact pins 90 and on the switching device 50 as contact sockets 68 (not shown in detail). 44 or stator teeth 46 on a side facing away from the motor shaft 30 of the electromobility sector 12 reversibly connectable. For this purpose, the electrical contact points 62 are each arranged in a ring shape on the adapter ring 80 and on an outer circumference of the switching device 50 . Thus, the switching device 50 can be very simply plugged into the adapter plate 80 of the stator 42 by the manufacturer and, if necessary, removed from it again. The contact pins 90 are in turn permanently soldered, crimped or welded to the windings 48 of the stator 42 . The contact sockets 92 of the switching device 50 can be connected in one piece to the switching elements 66, 68, 70, 72, 76 via copper tracks in the sense of a stamped grid or also via soldered, crimped or welded connections. Instead of a reversible plug-in connection between the switching device 50 and the adapter ring 80, it is alternatively also conceivable for the electrical contact points 62 between the switching device 50 and the adapter ring 80 or the windings 48 to be permanently soldered or welded. A direct crimp or screw connection of the windings 48 with the switching elements 66, 68, 70, 72, 76 or the electrical contact points 62 of the switching device 50 is also possible.

The electromechanical switching device 50 is constructed in two parts. It consists of a cup-shaped housing part 94 and a cover 96 which is designed as a rotatable mode switch 52 in the embodiment shown. In the pot-shaped housing part 94 out as contact sockets 92 formed electrical contact points 62 are arranged in a ring and beispielswiese per stamped tracks, cables or conductor tracks of a printed circuit board with the Anschlüs sen of the switching elements 66, 68, 70, 72, 76 connected. The connections of the switching elements 66, 68, 70, 72, 76 can, for example, be designed as contact slides or Contact springs 98 may be formed, which consist of a copper alloy such as CuSn6 or are formed as sandwich springs consisting of spring steel with a copper layer and slide over corresponding contact tracks 100 (cf. also FIG. 9).

In FIG. 8a, with reference to FIG. The contact sliders 98 of the switching elements 66, 68, 70, 72, shown only as points for better clarity, slide on the arcuate contact tracks 100, which are designed, for example, as copper tracks on the printed circuit board 102 and which are each gold-plated for better and more stable electrical conductivity , silver-plated, tin-plated, zinc-plated or nickel-plated surface coating. The same applies to the surfaces of the contact sliders 98. The first and second switching elements 66, 68 and the third and fourth switching elements 70, 72 each share a contact slider 98 as a common electrical contact point 62 (cf. also FIG. 6). The respective switching element 66, 68, 70, 72 is only electrically closed if both contact sliders 98 of a switching element 66, 68, 70, 72 have electrical contact with a contact track 100; otherwise it is open. In Figure 8a, in the shown position of the circuit board 102, the second and fourth switching elements 68, 72 for generating a parallel connection of the windings 48 of a stator pole 44 ¹ , 44", 44 ^m in connection with a delta connection of the phases U, V, W of the Electric motors 12 closed (see FIG. 4), while the first and third switching elements are opened 66, 70. It should be noted that the printed circuit board 102 shown in FIG windings 48 of a single stator pole 44 ^1. As a result, the switching device 50 for the windings 48 of the two other stator poles 44", 44 ^m must either have two further circuit boards 102, which are constructed in accordance with the circuit board 102 shown and are adjacent to the first circuit board 102 are arranged, but carry no more contact tracks 100 for the third and fourth switching elements 70, 72 on the inner circular path, or on two other circles each have the additionally required three first and six second switching elements 66, 68 per phase V, W or stator pole 44", 44 ^m . The individual contact tracks 100 must also be such in their arc length and Be designed positioning that no faulty switching states arise for the desired modes. Correspondingly, clearances or creepage distances 106 are provided on the printed circuit board 102 adjacent to the contact tracks 100 in order to generate the dead time T between the switching operations.

The at least one printed circuit board 102 is operatively connected indirectly (e.g. via a linkage, transmission or the like) or, as shown in Figure 8b, directly to the operating mode switch 52 in such a way that turning the operating mode switch 52 by the operator in the direction of rotation R causes the first and third switching elements to close 66, 70 and an opening of the second and fourth switching elements 68, 72 to produce a series connection of the windings 48 of a stator pole 44 ¹ , 44", 44 ^m in conjunction with a star connection of the phases U, V, W (cf. Figure 5 A subsequent turning back counter to the direction of rotation R then leads again to opening of the first and third switching elements 66, 70 and to closing of the second and fourth switching elements 68, 72 to produce a parallel connection of the windings 48 of a stator pole 44 ¹ , 44 ", 44 ^m in connection with a delta connection of the phases U, V, W. Since - as described at the beginning - the first and second scarf telements 66, 68 and the third and fourth switching elements 70, 72 are switched in a complementary manner to one another, the clearances or creepage distances 106 serve to avoid short circuits due to unintentional simultaneous closed states of the first and second or third and fourth switching elements 66, 68 or 70 , 72.

Alternatively, it is also conceivable that the first and second switching elements 66,

68 for parallel or series connection of the windings 48 of all three stator poles 44 are arranged on a first plate-shaped printed circuit board 102 and the switching device 50 has a second plate-shaped printed circuit board 102 which can be rotated independently of the first printed circuit board 102 and has the third and fourth switching elements 70, 72 for optional Delta or star connection of the three phases U, V, W or stator poles 44 has. In this way, the windings 48 and the phases U, V, W can be connected independently of one another by means of a correspondingly two-part operating mode switch 52 . The other switching elements 76 for the switchable load 74 to adapt to national conditions of the first supply voltage UH and/or the switching elements for switching over the position and speed sensors 78 (cf. FIG. 2) can also be implemented in an analogous manner. FIG. 8b shows a section through the switching device 50 according to FIG. 8a, with the housing part 94 and the cover 96 designed as an operating mode switch 52 also being shown. The contact tracks 100 interacting with the contact sliders 98 are arranged on their respective circular tracks on one side of the printed circuit board 102 . In the sectional view, only three contact tracks 100 and two contact sliders 98 are visible, which cause the two-th and fourth switching elements 68, 72 to close. The printed circuit board 102 is directly operatively connected to the operating mode switch 52, so that turning the operating mode switch 52 by the operator also directly causes the printed circuit board 102 to be turned. As already indicated in FIG. 8a, further printed circuit boards of the switching device 50 that are adjacent to the first printed circuit board 102 can also be operatively connected to the operating mode switch 52.

A further section through the switching device 50 is shown in FIG. 8c. In contrast to the exemplary embodiment according to FIG. 8a, the circuit board 102 is now printed on both sides with the contact tracks 100 for the switching elements 66, 68, 70, 72. Depending on the requirements of the electric motor 12, several such circuit boards 102 can of course also be used here for switching over the windings 48 of the stator poles 44 and the phases U, V, W.

Figure 9 shows two further exemplary embodiments of the switching device 50 in a perspective detail for the first and second switching elements 66, 68. These also apply as examples to the other switching elements of the switching device 50. In contrast to Figure 8, the carrier 104 is designed as a printed circuit board 102 now slidably arranged along a displacement direction R. Correspondingly, circuit board 102 also interacts with a movable mode switch 52 (not shown) for switching over first and second switching elements 66, 68 in such a way that moving mode switch 52 results in complementary opening and closing of first and second switching elements 66, 68 causes the contact tracks 100 printed on the printed circuit board 102 . Instead of a displaceable operating mode switch 52, a rotatable operating mode switch 52 can also be used in conjunction with a correspondingly designed linkage, which transforms the rotary movement into a linear movement. While in the section according to Figure 9a there are a total of two first and two second switching elements 66, 68 due to the edge printing of the circuit board 102 with the contact tracks 100 and the contact sliders 98 arranged on both sides of the circuit board 102, in Figure 9b this is the case due to the one-sided printing of the contact tracks 100 and the one-sided arrangement of the contact sliders 98 only have a first and a second switching element 66, 68. By printing the printed circuit board 102 on both sides with a corresponding number of contact sliders 98, however, more switching elements can also be implemented here, each in the horizontal direction are formed. As already shown in FIG. 8, a dead time T for switching over the operating modes can also be realized in FIG.

In the figures 10 and 11 further embodiments of the carrier 104 of the switching device 50 are shown. The individual components with identical reference numbers as in the previous FIGS. 8 and 9 will not be discussed further because of their identical mode of operation. Figure 10 is intended to make it clear in particular that a prism 108 (Figure 10a), a cuboid 110 (Figure 10b) or a U-profile 112 (Figure 10c) with correspondingly positioned contact tracks 100 can also be used as the carrier 104, with analogous FIG. 9 an opening and closing of the first and second switching elements 66, 68 is brought about by a linear displacement of the carrier 104. In FIG. 11, the carrier 104 is designed as a rotatable roller 114, in particular for the switching elements 76 for activating and deactivating the load 74 (cf. FIG. 6). For clarification, FIG. 11b shows a section through the roller 114 shown in perspective in FIG. 11a. Other possible carrier shapes would be a truncated cone, a sphere or the like.

All of the configurations of the electromechanical switching device 50 can also be combined with one another. A combination of an electromechanical and an electronic switching device 50 consisting of semiconductor switches or relays in the electrical processing device 10 is also conceivable. Instead of a printed circuit board 102 with printed contact tracks 100, the contact tracks 100 can also be designed as a stamped grid, which is overmoulded with a plastic and which then forms the cup-shaped housing part 94 itself. A schematic representation of the electrical processing device 10 is shown in FIG. The electrical processing device 10 can be topologically divided into a predominantly mechanical driven part 116 beyond a topological dividing line 118 and a supply and drive part 120 on this side of the topological dividing line 118. "This side" should be the side facing the electrical supply and "this side" should be the side facing the electrical supply. beyond” is to be understood as the side of the electrical processing device 10 facing the processing of a workpiece. "This side" is therefore to be regarded as functionally before and "beyond" as functionally behind the topological dividing line 118 . In particular, the driven part 116 is often designed specifically for the application of the electrical processing device 10 and can therefore, in contrast to the supply and drive part 120, generally not be produced and used universally for various types of electrical processing devices.

The main components of the output part 116 are the gear 24 and a special output mechanism 122 for the respective area of application of the electrical processing device 10. The output part 116 should therefore be understood as a mechanism that uses the drive energy of the electric motor 12 to use the electrical processing device 10 mechanically converts. An example of an output mechanism 122 of the output part 116 would be the percussion mechanism 26 mentioned in the description of FIG. However, the chassis of a vehicle, the grinder of a food processor, the device for generating and directing the air flow of a fan or the like can also form the driven mechanism 122 .

Components of supply and drive part 120 that are essential to the invention are power electronics 36, which have switchover device 50, and electric motor 12 be omitted for the sake of clarity. The power electronics 36 is divided into the first power electronics 36H for operation with the first supply voltage UH and the at least one second power electronics 36L for operation with the at least one second supply voltage UL, the first supply voltage UH is provided, for example, by a national power grid (indicated by the socket), while the at least one second supply voltage UL is supplied by the battery pack 20 . Thus, the first power electronics 36H is embodied as AC electronics and the at least one second power electronics 36L is embodied as DC electronics. The two power electronics 36H, 36L are preferably electrically isolated from one another in order to avoid voltage flashovers between them. Both power electronics 36H, 36L have in common the power bridge 34 for controlling the electric motor 12 via the switching device 50 by means of the PWM voltage UM. The switching device 50 is located within the electrical processing device 10 on this side of the topological dividing line 118 between the electric motor 12 and the power bridge 34. As described above, it can be designed as a modular assembly of the electric motor 12 or can be mechanically derived from the electric motor 12 Separate assembly elsewhere in the electrical processing device 10 are located. A division of the switching device 50 into an electronic and an electromechanical part or into several electromechanical or electronic parts within the electrical processing device 10 is possible.

With reference to FIG. 1, the battery pack 20 is in the form of a replaceable battery pack. A rechargeable battery or rechargeable battery pack 20 permanently integrated in the electrical processing device 10 is also conceivable. A mixed form of integrated battery and replaceable battery pack is also possible. In addition, several exchangeable battery packs 20 electrically connected in series or in parallel can be used on the electrical processing device 10 . Depending on the operating mode or the first supply voltage UH or the second supply voltage UL, the switching device 50 then activates the first or the second power electronics 36H, 36L.

FIG. 13 shows a further exemplary embodiment of an electrical processing device 10 in the form of a demolition hammer. In addition to the design of the predominantly mechanical driven part 116, a major difference from the impact wrench according to FIG. 1 is the power supply of the demolition hammer with two battery packs 20. In the case of two series-connected battery packs 20, each with 18 V, this results in a second supply voltage UL of 36VDC. In contrast to the impact wrench according to FIG. 1, the electric motor 12 can be assigned to a significantly higher performance class. however, without anything changing in the topological division of the electrical processing device 10 into the driven part 116 and the supply and drive part 120, as described in FIG. A detailed description of the driven part 116 of the demolition hammer with the driven mechanism 122 and the tool holder 18 together with the insert tool 32 should be omitted here, since this is of secondary importance for the invention.

As in the first exemplary embodiment according to FIG. 1, switching between the operating modes of the electric motor 12 can be carried out either manually by an operator or automatically by means of a sensor system 54 of the electrical processing device 10 . In addition to the sensor system 54 for detecting the position of the cover flap 56 for the mains cable 22 or its connector plug 60, the operator can also switch over the operating mode of the electric motor 12 via the operating mode switch 52, an HMI, an app or the like.

FIG. 14 shows the demolition hammer from FIG. 13 in a further exemplary embodiment. The switching device 50 of the power electronics 36, which is designed in particular electromechanically, is arranged separately from the electric motor 12 in the housing 14 of the demolition hammer. The operating modes can be switched over by the operator using the operating mode switch 52 . Furthermore, the first power electronics 36H are for operation with the first supply voltage UH, in particular with a mains voltage, and the second power electronics 36L are for operation with the second supply voltage UL, in particular with a battery voltage, as well as the power bridge 34 integrated therein for control of the electric motor 12 with the PWM voltage UM as a separate unit from the switching device 50 in the housing 14 hen vorgese. For this purpose, both the switching device 50 and the rest of the power electronics 36 each have separate sub-housings 124 which are in turn connected to the housing 14 in a fixed or integral manner. To decouple the switching device 50 or the entire power electronics 36 from any strongly vibrating components of the demolition hammer during operation, the output mechanism 122 and the electric motor 12 together with the gear 24 are mounted in the housing 14 by means of at least one damping element 126.

In this way it is possible to use the power electronics 36 or the changeover direction 50 from damage to the corresponding components and the electrical contacts. A spring in the form of a spiral, leaf or torsion spring, for example, which is arranged between the housing 14 and the output mechanism 122, the transmission 24 and/or the electric motor 12, can be used as the damping element 126. Rubber dampers or the like or at least one damping actuator controlled by the electronic control unit 38 (not shown) are also conceivable as damping elements 126 .

As an alternative or supplement to the vibration decoupling of the housing 14 from the output mechanism 122 and/or the electric motor 12, it can also be provided for the switching device 50 itself to be decoupled from the housing 14.

This is to be illustrated using different exemplary embodiments according to the following FIGS. 15 to 18, the switching device 50 being designed as an electronic switching device 50 with the sub-housing 124. It is also possible that, in the case of an electromechanical switching device 50, the modular subassembly consisting of the housing part 94 and the cover 96 designed as an operating mode switch 52 is mounted vibration-decoupled in the housing 14 of the electrical processing device 10. The switching device 50 can also be arranged in the housing 14 at a defined angle that is not equal to 0 or 180° to the electric motor 12 . A vibra tion decoupled storage of the modular assembly together with the elec romotor 12 in the housing 14 is conceivable.

In FIG. 15a, the switching device 50 arranged in the sub-housing 124 is mounted in a vibration-decoupled manner on corresponding holding elements 130 of the housing 14 for receiving the rubber buffers 128 via damping elements 126 designed essentially as square rubber buffers 128 . A plan view is shown on the left-hand side of FIG. 15a and a side view is shown on the right-hand side. The sub-housing 124 is therefore mounted in the housing 14 via a total of eight rubber buffers 128 and eight retaining elements 130 . Vibrations of the housing 14 can thus be sufficiently dampened to protect the switching device 50 from damage during operation of the electrical processing device 10 . FIG. 15b shows the top view of a second possible embodiment of the damping elements 126 as a poly gone rubber buffer 128 with at least one internal air chamber 132. FIG. 15c shows a third exemplary embodiment of the damping element 126 as a substantially barrel-shaped rubber buffer 130 with corresponding lateral air chambers 132 that completely encloses the sub-housing 124 at least in one direction. With particular advantage, the switching device 50 with its sub-housing 124 can simply be plugged into this rubber buffer 130. Both in FIG. 15b and in FIG. 15c, holding elements 130 are provided on the housing 14, the shape of which is adapted in a complementary manner to the shape of the damping elements 126 for the best possible fixing and mounting.

Figure 16 shows further embodiments of the damping element 126 for the switching device 50. In Figure 16a, the damping element 126 is embodied as a stamped rubber foil 134, which is stretched over four retaining elements 130 of the housing 14, embodied as eyelets or domes 136, and which support the sub-housing 124 of the Switching device 50 carries almost hanging. For this purpose, the sub-housing 124 has a projection 138 which engages through an opening in the rubber film and which is fixed to the rubber film 134 via six corresponding retaining elements 140 . In FIG. 16b, the damping element 126 is designed as a rubber ring 142 which is mounted on the housing 14 via four eyelets or domes 136 and which carries the sub-housing 124 of the switching device 50 hanging via four retaining elements 140 designed as hooks. FIG. 16c shows a further possible embodiment of the rubber foil 134 from FIG. 16a, which is now only mounted on two eyelets or domes 136 in the housing 14. In contrast to FIG. 15, where the at least one damping element 126 exerts a compressive force F on the subhousing 124 or the switching device 50, in FIG. 16 it is a tensile force F.

In FIGS. 17 and 18, the damping elements 126 are designed as springs, a compressive force F acting in FIG. 17 analogously to FIG. 15 and a tensile force F acting in FIG. 18 analogously to FIG. In FIGS. 17a, 17b and 17c, the damping elements 126 are each designed as leaf springs 144, as spiral springs 146 and as leg fenders 148, which, depending on the design, have correspondingly designed holding elements 130, 140 on the housing 14 of the electrical processing device 10 or on the sub-housing 124 of the switching device 50 interact. Figures 18a and 18b each show a damping element 126 designed as a tension spring 150 and as a bending or torsion spring 152, which is mounted vibration-decoupled on the one hand on eyelets or domes 136 of the housing 14 and on the other hand on specially designed holding elements 140 of the sub-housing 124.

Further exemplary embodiments of an electrical processing device 10 are shown in FIGS. The electrical processing device 10 in Figure 19 is a hammer drill with a drive mechanism 122 designed as a pneumatic impact mechanism and, for example, a tool holder 18 designed as an SDS drill chuck for an insert tool 32 designed as an SDS drill. Also that of the motor shaft 30 of the electric motor 12 driven gear 24 is specially designed for the application of the hammer drill. The same applies to the angle grinder shown in FIG. 20, the industrial vacuum cleaner shown in FIG. 21 and the lawn mower shown in FIG. Here, too, the output part 116 is specially adapted to the purpose of use of the electrical processing device 10, without wanting to go into more detail below, since this is of lesser importance for the invention as such. At this point, however, it should be pointed out again that the invention can also be used in many other electric motor-driven processing devices with at least two different supply voltages, such as kitchen appliances, construction machinery, vehicles, airplanes, ships, etc.

Figures 19 to 22 illustrate, corresponding to Figure 13, a topological division of the respective electrical processing device 10 into the predominantly mechanical driven part 116 beyond the topological dividing line 118 and the supply and drive part 120 on this side of the topological dividing line 118. The switching device 50 is inside the housing 14 of the electrical processing device 10 is always topologically separated from the friction part 116 such that it is functionally arranged in front of the electric motor 12 and the driven part 116, in particular as part of the power electronics 36. Furthermore, each electrical processing device 10 has in common that the power processing electronics 36 is divided into first power electronics _36H , in particular AC electronics, for operation with the first supply voltage UH and at least one second power electronics 36L, in particular DC electronics, for operation with the at least one second supply voltage UL, with the first and the at least one second electronic power system 36H, 36L are electrically isolated from one another. In addition, the switching device 50 is always arranged in the housing 14 on a side of the electric motor 12 which is remote from the motor shaft 30 .

The rotary hammer shown in Figure 19 differs significantly from the demolition hammer shown in Figure 13 in terms of its application and the driven part 116 designed for it, but both have in common the roughly power class and the energy supply via two battery packs 20. Both can therefore be electric Processing devices 10 each have a very similar supply and drive part 120 . With particular advantage, the electric motor 12 together with the switching device 50 or the complete power electronics 36 can be used as a modular assembly in both electrical processing devices 10, which significantly simplifies the manufacture and maintenance of the electrical processing devices 10 and makes it more cost-efficient. The same applies to other electrical processing devices 10 of similar performance classes, such as the industrial vacuum cleaner shown in FIG. 21 and the lawn mower shown in FIG. 22 or the rotary impact wrench shown in FIG. 1 and the small angle grinder shown in FIG.

Finally, it should be pointed out that the exemplary embodiments shown are neither limited to FIGS. In addition, all exemplary embodiments can alternatively be implemented with a classic DC motor, depending on the performance and cost requirements. Both the rechargeable batteries 20 and the electronics for charge management can either be integrated directly in the electrical processing device 10 or connected externally to the electrical processing device 10 via a cable.

Claims

Expectations

1. Electrical processing device (10) with

• a housing (14),

• Power electronics (36) for converting a first supply voltage (UH), in particular for mains operation, and at least one second supply voltage (UL) that is significantly different from the first supply voltage (UH), in particular for battery operation, into a pulse-width-modulated motor voltage (AROUND),

• an electric motor (12) which can be acted upon by the motor voltage (UM) and has a rotor (40) and a stator (42), the stator (42) having three stator poles (44) and each stator pole (44 ¹ , 44", 44 ^m ) has an integral multiple of stator teeth (46), each with a plurality of windings (48) for driving the rotor (40), the windings (48) of the stator teeth (46) being designed in terms of their type and/or number such that the electric motor (12) can be operated via three phases (U, V, W) either with the first or with the at least one second supply voltage (UH, UL),

• one of the electric motor (12) driven output part (116) for converting the electric motor (12) generated drive energy into a use of the electrical processing device (10) erforder Liche mechanical energy and

• a switching device (50) which switches the windings (48) of the electric motor (12) in series and/or in parallel for selective operation with the first or the at least one second supply voltage (UH, UL), characterized in that within of the housing (14), the switching device (50) is topologically separated from the output part (116) in such a way that it is functionally arranged in front of the electric motor (12) and the output part (116), in particular as part of the power electronics (36).

2. Electrical processing device (10) according to claim 1, characterized in that the switching device (50) is designed such that it additionally connects the phases (U, V, W) of the electric motor (12) in a star connection or in a delta connection can.

3. Electrical processing device (10) according to one of the preceding claims, characterized in that the power electronics (36) have a first power electronics (36H), in particular AC electronics, for operation with the first supply voltage (UH) and at least a second power electronics (36L), in particular DC electronics, for operation with the at least one second supply voltage (UL), the first and the at least one second power electronics (36H, 36L) being electrically isolated from one another.

4. Electrical processing device (10) according to any one of the preceding claims, characterized in that the switching device (50) is a modular assembly (94, 96) of the electric motor (12).

5. Electrical processing device (10) according to one of the preceding claims, characterized in that the electric motor (12) has a motor shaft (30) and that the switching device (50) is reversible on a side of the electric motor (12) facing away from the motor shaft (30). is attached.

6. Electrical processing device (10) according to claim 5, characterized in that the reversible fastening of the switching device (50) on the electric motor (12) takes place in such a way that contact sockets (92) of the switching device (50) electromechanically engage with contact pins ( 90) an adapter plate (80) connected to the stator (42) of the electric motor (12).

7. Electrical processing device (10) according to claim 6, characterized in that the switching device (50) has switching elements (66, 68, 70, 72) for parallel or series connection of the windings (48) and for star or delta connection of the phases ( U, V, W) of the electric motor (12), the contact sockets (92) being electrically connected to the switching elements (66, 68, 70, 72).

8. Electrical processing device (10) according to any one of the preceding claims,

6 or 7, characterized in that the contact pins (90) of the adapter plate (80) are electrically connected to the windings (48) of the electric motor (12).

9. Electrical processing device (10) according to one of the preceding claims 6 to 8, characterized in that the assembly consisting of the electric motor (12), the adapter plate (80) and the switchover device (50) along a path through the motor shaft (30) defined axis is constructed.

10. Electrical processing device (10) according to any one of the preceding claims,

1 to 4 characterized in that the electric motor (12) has a motor shaft (30) and that the switching device (50) in the housing (14) on one of the motor shaft (30) facing away from the electric motor (12) is arranged.

11. Electrical processing device (10) according to one of the preceding claims, characterized in that the switching device (50) is arranged at a defined angle to the electric motor (12) in the housing (14).

12. Electrical processing device (10) according to one of the preceding claims, characterized in that the electrical processing device (10) is a hand tool.