Axial flux machine for an electric power tool and electric power tool having an axial flux machine

Abstract

Axial flux machine (10), in particular single-sided axial flux motor, for an electric tool (34), having a machine shaft (12), in particular motor shaft, a disc-shaped stator (20) and a disc-shaped rotor (14) arranged adjacent to the stator (20) in the axial direction (A) of the machine shaft (12), the stator (20) being configured as a winding carrier (22) with a plurality of stator teeth (44) of at least one stator winding (24), the rotor (14) being torsionally connected to the machine shaft (12) and being able to be placed in rotational motion relative to the stator (20). The rotor (14) of the axial flux machine (10) has a rotor yoke (62) which is configured as a bidirectional fan (64) or is permanently connected, in particular bonded, to a bidirectional fan (40) by a joining process, the bidirectional fan (40) having at least one radial (66) and axial air flow direction (68) for cooling the axial flux machine (10), in particular the stator (20) and the rotor (14). An electric tool (34) having an axial flux machine (10) according to the invention is also described.

Description

TECHNICAL FIELD

[0001] The invention relates to an axial flux machine for an electric working tool, in particular a single-sided axial flux motor, and to an electric working tool having an axial flux machine according to the generic subject matter of the independent claims. BACKGROUND

[0002] Compared to conventional electric motors having a radial flux direction, axial flux machines have the advantage that they are very efficient and have a significantly shortened construction length. Furthermore, a higher torque density or power density can be achieved with the same outer diameter. These improvements are due, inter alia, to a larger air gap area with a similar construction volume. Furthermore, due to the smaller iron volume of the rotating components, a higher efficiency is achieved over a larger speed range.

[0003] The construction of the stator of an axial flux machine is relatively expensive due to the required 3D flux guidance. Usually the nutung of the lamination stack has to be punched before the winding process of the stator winding. Furthermore, due to the individual sheets the following disadvantage arises, that the pole shoes only achieve a tangential protrusion, an external winding of the stator teeth with protruding pole shoes is not possible, which leads to a small fill factor of the stator winding and to a correspondingly reduced efficiency.

[0004] An axial flux machine having a curved and wound lamination stack as a winding carrier is known from DE 10 2015 223 766 A1. The stator of the axial flux machine has a sintered carrier structure composed of a soft magnetic material and an insert configured as a lamination stack. The insert is attached to the carrier structure by form locking and / or force locking and at least partially forms the pole shoes of the axial flux machine. The lamination stack is formed on a single sheet composed of soft iron by means of individual, stacked layers. The individual sheets are attached to one another in an electrically insulated manner from the respectively adjacent sheet.

[0005] High-efficiency electric machines must have a very effective cooling of the components that have losses. In order to force-cool these components, air flows are usually used as cooling medium, which are conveyed through the electric motor in an essentially axial direction of the motor shaft by means of a fan. However, in the case of axial flux machines, an air flow only in the axial direction is not sufficient. The reason for this is the arrangement of the stator winding, the air gap of which between the stator teeth extends orthogonally to the machine axis in the radial direction. Therefore, an air flow that is mainly oriented in the radial direction must be generated, in particular to cool the stator winding. Then, after the air has entered the axial flux machine in the radial direction, the air flow must be diverted in the axial direction and guided through the motor in order to cool the stator and the rotor. SUMMARY

[0006] It is the task of the present invention to provide a cooling air guide for an axial flux machine which is improved with respect to the prior art.

[0007] Advantages of the invention

[0008] The invention relates to an axial flux machine, in particular a single-sided axial flux motor, for an electric machining tool, having a machine shaft, in particular a motor shaft, a disc-shaped stator and a disc-shaped rotor arranged adjacent to the stator in the axial direction of the machine shaft, wherein the stator is configured as a winding carrier having a plurality of stator teeth for at least one stator winding, and the rotor, which is connected to the machine shaft against rotation, can be placed in rotational motion relative to the stator.

[0009] To solve the task set, the rotor has a rotor yoke which is configured as a bi-directional fan or which is permanently connected, in particular bonded, to a bi-directional fan by a joining process, wherein the bi-directional fan has at least one radial and one axial air flow direction for cooling the axial flux machine, in particular the stator and the rotor. In this way, a very efficient cooling of the axial flux machine can be achieved without additional drive components for the fan and without an axial structural space extension of the axial flux machine, while at the same time the largest possible diameter of the fan can be achieved.

[0010] Since the cooling is not only important for the axial flux machine or its components, but also for the electric machining tool operated by means of the axial flux machine, the invention also relates to an electric machining tool, in particular an electric power tool, having an axial flux machine according to the invention, in particular an axial flux motor according to the invention.

[0011] In the context of the invention, an electric machining tool is in particular to be understood as a battery-operated or mains-operated electric power tool which is used to machine workpieces by means of electrically driven insert tools. Here, the electric machining tool can not only be configured as a hand-held electric power tool, but also as a stationary electric power tool. In this context, typical electric power tools are hand-held or stand-mounted drills, screwdrivers, impact drills, drill hammers, demolition hammers planers, angle grinders, vibration sanders, polishers or the like. However, motor-driven garden appliances, such as lawn mowers, lawn trimmers, branch saws or the like, can also be considered as electric machining tools. In addition, the invention can be applied to axial flux machines in household appliances or kitchen appliances, such as washing machines, dryers, vacuum cleaners, blenders, etc.

[0012] The term "axial flux machine" can here include not only axial flux motors, but also axial flux generators for converting mechanical energy into electrical energy. Likewise, an axial flux machine is also to be understood as an axial flux motor which is used at least sometimes for regenerating electrical energy from mechanical energy, for example when the axial flux motor is in an electrically dynamic brake.

[0013] In an advantageous development, the rotor yoke, which is configured as a bidirectional fan, consists of a soft-magnetic material, in particular of a soft-magnetic iron. This ensures an optimized guidance of the magnetic flux for achieving a torque as high as possible.

[0014] The bidirectional fan causes a radial intake of the air flow, accompanied by an axial throughflow of the axial flux machine and a radial escape of the heated air flow. Here, the radial intake of the air flow takes place on the one hand through the air gap between the stator teeth of the winding carrier and on the other hand in the region of the first stator yoke of the stator, in particular on the end side of the first stator yoke which is distal with respect to the rotor. This ensures on the one hand an effective direct cooling of the stator winding and on the other hand an indirect cooling of the stator winding by means of a direct cooling of the first stator yoke.

[0015] The axial air flow direction for the axial throughflow of the axial flux machine is essentially caused by a plurality of axial openings arranged in the inner radius region of the rotor yoke, while the radial air flow direction for the radial escape of the heated air flow is caused by a plurality of radially arranged radial air vanes in the outer radius region of the bidirectional fan. Thus, all strongly heated components of the axial flux machine are circulated by cooling air and effectively cooled. BRIEF DESCRIPTION OF DRAWINGS

[0016] In the following the application is explained according to Figures 1 to 10 The application is exemplarily explained, wherein identical reference signs in the figures designate identical components with identical functions.

[0017] which shows

[0018] Figure 1 : a sectional view of an axial flux machine according to the application in the form of a single-sided axial flux motor in a first embodiment,

[0019] Figure 2 : a schematic view of a further embodiment of a stator of an axial flux machine according to the application,

[0020] Figure 3 : Figure 2 : an exploded view of the stator in a schematic view without stator winding,

[0021] Figure 4 : a partial schematic view of a stator according to the application in a further embodiment,

[0022] Figure 5 : A schematic view of another embodiment of the rotor of the axial flux machine according to the present invention.

[0023] Figure 6 A schematic view of the housing of an axial flux generator according to the present invention.

[0024] Figure 7 : Figure 6 A further schematic view of the empty housing of the axial flux engine according to the present invention.

[0025] Figure 8 A schematic cross-sectional view of another embodiment of the cooling air guiding device in an axial flux machine according to the present invention.

[0026] Figure 9: Two embodiments of the delta parallel circuit of the single-tooth winding of the stator winding of the axial flux engine according to the present invention, and

[0027] Figure 10 Electrical discharge machining tools, particularly power tools, that have an axial flux mechanism according to the invention, which are in the form of a drill hammer. Detailed Implementation

[0028] exist Figure 1 A cross-sectional view of a first embodiment of the axial flux transfer motor 10 according to the present invention is shown. The axial flux transfer motor 10 can also be configured as an axial flux motor or an axial flux generator. A disc-shaped rotor 14 is arranged torsionally on the machine shaft 12 of the axial flux transfer motor 10. The rotor 14 is constructed as a plate-shaped ring 16 made of soft magnets and carries alternately magnetized magnetic rings 18, which will also be referred to Figure 5 The magnetic ring will be discussed in more detail. However, since the rotor 14 is generally not exposed to alternating fields and the risk of eddy current losses is relatively small, the rotor 14 can also be made of a non-soft magnetic material (e.g., iron) or of a soft magnetic steel with a low carbon content. In the axial direction A of the motor shaft 12, a similarly disc-shaped stator 20 is adjacent to the rotor 14, or rather, to the magnetic ring 18. This stator is configured as a winding carrier 22 for at least one stator winding 24 (see...). Figure 2 The stator has a first stator yoke 26, which serves as a magnetic yoke for the magnetic field generated by the stator windings 24 and the magnetic ring 18. The rotor 14 can be put into rotational motion relative to the stator 20, or stator windings 24, by the motor shaft 12. For this purpose, the motor shaft 12 is connected on the one hand by a first bearing 28 integrated into the stator yoke 26, and on the other hand by a housing 32 received in the electrical discharge machining tool 34 (see...). Figure 10The second bearing 36 in the first bearing 28, for example configured as a fixed bearing 30, and the second bearing, for example configured as a floating bearing 38, are rotatably supported. The first and second bearings 28, 36 are preferably configured as ball bearings. The first bearing 28 is directly integrated into the winding carrier 22 and / or the first stator yoke 26. This first bearing can thus be, for example, pressed or injected. Since the axial flux machine, in particular the single-sided axial flux machine, has a very high traction in the axial direction A of the machine shaft 12 in the air gap between the rotor 14 and the stator 20, this traction can be supported by the first bearing 28 configured as a fixed bearing 30 in the first stator yoke 26. It is thus not necessary to receive the axial forces by the housing 32 of the electrical machining tool 34 and / or by the housing of the axial flux machine (see Figure 6 and Figure 7 ).

[0029] For cooling the axial flux machine 10, a fan wheel 40 is arranged on the machine shaft 12 in a torque-proof manner, which fan wheel transports cooling air through the axial flux machine 10. For this purpose, the fan wheel 40 preferably sucks in cooling air in the radial direction in order to then transport the cooling air in the axial direction through the axial flux machine 10.

[0030] Figure 2 A schematic view of another embodiment of the disc-shaped stator 20 of the axial flux machine 10 according to the application is shown. The stator 20 essentially comprises a first stator yoke 26, a second stator yoke 42 arranged adjacent to the first stator yoke in the axial direction A of the machine shaft 12, and a winding carrier 22 arranged adjacent to the second stator yoke 42 in the axial direction A of the machine shaft 12. The winding carrier 22 essentially consists of a plurality of, in particular six, stator teeth 44, which carry a stator winding 24, wherein each stator tooth 44 is assigned a single tooth winding 46 of the stator winding 24. With reference to Figure 9a , the single tooth windings 46 are electrically connected to one another in a delta parallel circuit 48.

[0031] The stator teeth 44 and the first stator yoke 26 of the stator 20 are formed from a composite material (Soft Magnetic Composites, SMC) and are permanently connected to one another, in particular bonded, by a joining process. The SMC material consists of a high-purity iron powder which has a special surface coating on each individual particle. This electrically insulating surface ensures a high electrical resistance even after pressing and heat treatment, which in turn minimizes or even avoids eddy current losses. It is particularly advantageous compared to prior art axial flux machines that an axial flux machine which is extremely resistant to mechanical stress and at the same time very high-performing and efficient or a high-torque axial flux motor can thus be provided. The joining of the stator teeth 44 to the first stator yoke 26 can be achieved by applying the stator winding 24 or in other words the single tooth winding 46 to the stator teeth 44 during the joining process. In this way a high fill factor of the stator winding 24 can be achieved.

[0032] Unlike the first stator yoke 26, the second stator yoke 42 of the rotor 20 consists of a soft magnetic iron and is configured as a lamination stack 48 (see Figure 3 ), which has a plurality of, in particular six, slots 50 which are distributed over the outer circumference of the lamination stack and serve to receive the composite material. The number of slots 50 here corresponds to the number of stator teeth 44. The second stator yoke 42 thus stabilizes the stator 20 in the case of strong mechanical stress and, due to its high magnetic permeability, ensures an improved magnetic flux guidance. The slotting of the lamination stack 48 not only facilitates better reception of the composite material and thus results in a higher stability of the stator 20, but also ensures an optimized guidance of the eddy currents essentially caused by the stator winding 24.

[0033] According to Figure 3 , the second stator yoke 42 for receiving the stator teeth 44 has annularly arranged, circular-arc-segment-shaped notches 52, wherein each slot 50 interrupts the outer circumference of the second stator yoke 42 up to the respectively radially inwardly placed notch 52. Each stator tooth 44 is formed by a circular-arc-segment-shaped tooth flange 54, which penetrates the circular-arc-segment-shaped notches 52 of the second stator yoke 42, and a circular-arc-segment-shaped carrier frame 56, which surrounds the tooth flange 54 and has a circumferential U-shaped profile 58 for receiving the stator winding 24 or in other words the single tooth winding 46. The tooth flange 54 and the carrier frame 56 are permanently connected to one another, in particular bonded, by a joining process.

[0034] Figure 4 A schematic view of a partial view of a stator 20 according to the application is shown in a further embodiment. Here, the stator teeth 44 or in other words their tooth flanges 54 (see Figure 3) are guided through the recesses 52 of the second stator yoke 42 and permanently connected with the first stator yoke 26 by means of laser welding. In each face of the stator teeth 44 lying on the first stator yoke 26, a bore hole 60 in the first stator yoke 26 is arranged approximately centrally, through which the stator teeth 44 can be connected with the first stator yoke 26 by means of laser welding. The weld extends over the entire circumference of the bore hole 60 in order to permanently connect the first stator yoke 26 and the respective stator tooth 44. However, it is also possible that the weld extends only pointwise over the circumference of the bore hole 60. Due to the welding in the center of each stator tooth 44, the guidance of the magnetic flux is only slightly affected and a high planar parallelism of the stator teeth 44 and the radial air gap between them can be achieved. Due to the avoidance of the adhesive bond, an adhesive bond gap between the stator teeth 44 and the first stator yoke 26 can be effectively avoided and the stator teeth 44 and the first stator yoke 26 do not need to be fixed during the hardening of the adhesive bond. With reference to Figure 1 It is also possible to consider, instead of the second stator yoke 42, that the first stator yoke 26 is directly connected with the stator teeth 44 composed of a composite material, in particular by means of the bore holes 60 in the first stator yoke 42, which is configured as a plate-like ring 16 made of soft magnetic iron.

[0035] In Figure 5 a cross-sectional view of a rotor 14 of an axial flux machine 10 according to the application is shown. The rotor 14 is configured as a plate-like ring 16 made of soft magnetic iron. In addition, the rotor carries alternatingly polarized magnetic rings 18, which act together with the stator windings 24 of the stator 20 in order to put the rotor 14 into rotational motion in the motor mode or to induce a voltage into the stator windings 24 in the generator mode. The magnet segments of the magnetic rings 18, which are not shown in detail, are configured in a circular segment shape, such that the faces of the magnets coincide with the circular segment-shaped stator teeth 44 to the greatest extent in order to achieve an optimized magnetic flux while achieving a high torque. Instead of the alternatingly polarized magnetic rings 18, it is also possible to consider rings with embedded single magnets. As described above, the rotor 14 is generally not exposed to an alternating field, so that no or only very little eddy current losses occur here. Therefore, the rotor 14 of the axial flux machine 10 can also be composed of a non-soft magnetic material instead.

[0036] In a preferred configuration of the application, the plate-shaped ring 16 of the rotor 14 is configured as a rotor yoke 62 which is either permanently connected, in particular bonded, to the bidirectional fan 40 by a joining process or which itself serves as a bidirectional fan 64. Here, the bidirectional fan 40, 64 has at least one radial air flow direction 66 and an axial air flow direction 68 in order to cool the axial flux machine 10, in particular the stator 20 or the stator winding 24 and the rotor 14. The radial air flow direction 66 is here essentially achieved by a plurality of radial air vanes 70 which are arranged circularly in the outer radius region of the bidirectional fan 40, 64, while the axial air flow direction 68 is achieved by a plurality of axial openings 72 which are arranged in the inner radius region of the rotor yoke 62.

[0037] Thus, with reference to Figure 6 , the bidirectional fan 40, 64 causes a radial intake 74 of an air flow 76 with an axial throughflow 78 of the stator 20 and the rotor 14 of the axial flux machine 10 and a radial escape 80 of the heated air flow 76 from the housing 82 of the axial flux machine 10. The radial intake 74 of the air flow 76 takes place on the one hand through the air gap between the stator teeth 44 (see Figure 2 ) and on the other hand in the region of the first stator yoke 26 of the stator 20, in particular on the end side 84 of the first stator yoke 26 which is distal with respect to the rotor 14.

[0038] In Figure 7 , the axial flux machine 10 is shown with the housing 82 of the axial flux machine together with a cover 86 which closes the housing. Figure 8 The housing 82 is shown without the axial flux machine 10 and the cover 86. The housing 82 is open on one side in order to receive the cover 86 and has an essentially closed end side 88 (see Figure 8 ) opposite. The cover 86 closes the housing 82 and thus force-locked connects the stator 20 and the rotor 14 of the axial flux machine 10. "Essentially closed" is to be understood in this context in that the end side 88 can have a plurality of openings 90, for example for cooling, as cable passages and / or as a feedthrough for the machine shaft 12, but alternatively also in that the end side 88 is completely closed. The housing 82 is configured as a cylinder and fixes the stator 20 such that a defined air gap is produced between the rotor 14 or the magnetic ring 18 of the rotor and the stator 20 or the winding carrier 22 of the stator. In order to reduce or avoid eddy current losses, the housing 82 is made of a magnetically insulating material, for example plastic (PA66), which has as low a magnetic permeability as possible. The cover 86 can also be configured accordingly.

[0039] The first bearing 28, which is configured as a fixed bearing 30, is fixed in a bearing flange 92 of the cover 86, which fixed bearing supports the machine shaft 12 in a non-displaceable manner, while the substantially closed end side 86 of the housing 82 has a second bearing 36, which is configured as a floating bearing 38, in a further bearing flange 94 for supporting the machine shaft 12 in a displaceable manner. In this way, it is possible to push the housing 82 away very easily after assembly of the axial flux machine 10 and to remove it again for possible maintenance work.

[0040] On the open side of the housing, a plurality of notches 96 and tabs 98 are arranged alternately in a manner distributed over the circumference of the housing 82 in order to receive and fix the stator 20. Here, radially protruding portions (see Figure 2 and Figure 3 ) distributed over the circumference of the first and second stator yokes 26, 42 of the stator 20 are fitted into the corresponding notches 96 of the housing 82. Correspondingly, the cover 86 also comprises radially protruding portions configured as tabs 106, which are fitted into the notches 96 of the housing 82. In this way, it is possible to guide the high axial forces of the axial flux machine 10 in the direction of the cover 86. At least one drill hole 100 is provided in each tab 98 of the housing 82, which drill hole serves to fix the cover 86 and thus also the stator 20 by means of a corresponding fastening means 102, in particular a screw 104. The fastening means 102 transmit the axial forces of the axial flux machine 10 to the housing 82 and thus bear a shearing force.

[0041] The opening 90 on the substantially closed end side 88 of the housing 82 is configured as a radially and / or axially acting ventilation opening 104, in particular as a ventilation outlet 106, for cooling the axial flux machine 10 (see also Figure 6 ). Furthermore, the housing 82 has a plurality of radially acting ventilation openings 108, in particular ventilation inlets 110, distributed over the circumference approximately centrally between the substantially closed end side 88 and the open side opposite in the axial direction A. In addition to the openings 90 for cooling the axial flux machine 10, further openings 90 are also provided in the tabs 98 of the housing 82, which further openings can be used as a lead-through 112 for sensor lines or the like.

[0042] In Figure 9a , the circuit diagram of the stator winding 22 is shown as six single tooth windings 46 of the stator teeth 44 (see Figure 2A triangular parallel circuit 48 for the single tooth windings 46 of one phase is shown in detail. For each phase, two single tooth windings 46 are connected in parallel between the connection points U and V, V and W or W and U, respectively. The triangular circuit itself causes the entire supply voltage to drop across each single tooth winding 46. This results in an increase in the number of turns of the single tooth winding 46 in order to achieve a certain required rotational speed when the motor is running or a certain required energy yield when the generator is running. By means of the additional parallel circuit, it is possible to increase the winding wire diameter in a particularly advantageous manner and thus to reduce the resulting internal resistance. The triangular parallel circuit 48 thus enables a reduction in the internal resistance of the axial flux machine 10 compared to the common star circuit, which leads to a significant increase in the power capability of the axial flux machine 10 compared to the solutions to date. Figure 9b An alternative embodiment of a triangular parallel circuit 48 for a total of nine single tooth windings 46 of the stator winding 22 is shown.

[0043] In Figure 10 An embodiment of an electric machining appliance 34 having an axial flux machine 10 according to the application is shown in accordance with Figure 1 The electric machining appliance 34 is configured as an electric power tool 112 in the form of an electric mains-operated hammer drill having an electric motor-driven impactor 114, which places a drill chuck 116 for a not shown insert tool into rotational and / or impact motion. Here, the specific configuration of the hammer drill is not explored in detail, since this is sufficiently known to the person skilled in the art. The electric machining appliance can also be understood as any other electric battery-operated or electric mains-operated electric power tool 112 for machining workpieces by means of electrically driven insert tools. Here, the electric machining appliance can be configured not only as a hand-held electric power tool, but also as a stationary electric power tool. In this context, typical electric power tools are hand-held or stand-mounted drills, screwdrivers, impact drills, hammer drills, demolition hammers grinders, vibration sanders, polishers or the like. However, motor-driven garden appliances, such as lawn mowers, lawn trimmers, branch saws or the like, can also be considered as electric machining appliances. In addition, the application can be applied to axial flux machines in household appliances or kitchen appliances, such as washing machines, dryers, vacuum cleaners, mixers or the like.

[0044] The axial flux machine 10 of the electric power tool 112, which works as an axial flux motor, drives the percussion machine 114 by means of the machine shaft 12 of the axial flux machine in a known manner via a transmission 118. Here, the actuation of the axial flux machine 10 takes place by means of a main switch 122 arranged in a D-shaped handle 120 of the electric power tool 112, which main switch acts jointly with electronic devices not shown for energizing the stator winding 22 connected in a delta parallel circuit 48. The stator 20 of the axial flux machine 10 is received directly in the housing 32 of the electric power tool 112. For this purpose, the stator 20 and the housing 32 are permanently connected to one another, in particular glued, by a joining process. However, alternatively, the stator 20 can also be permanently connected to the housing 32 by a form closure, in particular verpressen. It can further be provided that the housing 32 of the electric power tool 112 or a transmission housing 122 receives a second bearing 36, in particular a floating bearing 38, connected to the machine shaft 12 of the axial flux machine 10. Instead of the axial flux machine 10 shown according to Figure 1 , the electric power tool 112 or the electric working tool 34 can also (without limiting the invention) be equipped with an axial flux machine 10 according to Figures 6 to 8 .

[0045] Finally, it should be noted that the invention is not limited to the shown embodiment according to Figures 1 to 10 , nor to the mentioned number of stator teeth, single tooth windings and magnets of the magnetic ring.

Claims

1. An axial flux machine (10) for an electrically operated appliance (34), the axial flux machine having a machine shaft (12), a disc-shaped stator (20) and a disc-shaped rotor (14) arranged adjacent to the stator (20) in the axial direction (A) of the machine shaft (12), wherein, The stator (20) is configured as a winding carrier (22) with a plurality of stator teeth (44) for at least one stator winding (24), and a rotor (14) which is connected to the machine shaft (12) against rotation and is able to be placed in rotational motion relative to the stator (20), wherein the rotor (14) has a rotor yoke (62) which is configured as a bidirectional fan (64) or which is permanently connected to a bidirectional fan (40) by a joining process, wherein the bidirectional fan (40) has at least one radial air flow direction (66) and an axial air flow direction (68) in order to cool the axial flux machine (10), and the bidirectional fan causes a radial intake (74) of an air flow (76), accompanied by an axial throughflow (78) of the axial flux machine (10) and a radial escape (80) of the heated air flow (76), characterized in that the radial intake (74) of the air flow (76) takes place on the one hand through air gaps between the stator teeth (44) of the winding carrier (22) and on the other hand in the region of a first stator yoke (26) of the stator (20).

2. The axial flux machine (10) of claim 1, characterized in that The axial flux machine (10) is a single-sided axial flux motor.

3. The axial flux machine (10) of claim 1, characterized in that, The machine shaft is a motor shaft.

4. The axial flux machine (10) of claim 1, characterized by The rotor yoke is bonded to the bidirectional fan (40).

5. The axial flux machine (10) of claim 1, characterized by The radial intake (74) of the air flow (76) takes place on an end side (84) of the first stator yoke (26) of the stator (20) which is distal with respect to the rotor (14).

6. The axial flux machine (10) according to any one of claims 1 to 5, characterized in that The rotor yoke (62) which is configured as a bidirectional fan (64) consists of a magnetically soft material.

7. The axial flux machine (10) according to any of the preceding claims 1 to 5, characterized in that Substantially a plurality of radial air blades (70) which are arranged in an outer radius region of the bidirectional fan (40, 64) cause the radial air flow direction (66), while a plurality of axial openings (72) which are arranged in an inner radius region of the rotor yoke (62) cause the axial air flow direction (68).

8. An electric working tool (34) having an axial flux machine (10) according to any one of the preceding claims.

9. The electro-processing tool (34) according to claim 8, characterized in that The electric working tool (34) is an electric power tool (112). The electric working tool (34) is an electric power tool (112).

Images