Drive motor and power tool including drive motor

Abstract

[Solution] A drive motor (120) for an electric tool that drives a tool receiving part of the electric tool, the drive motor (120) comprising a rotor (210) arranged on a motor shaft (250), an inner stator (230), and an outer stator (220), wherein the rotor (210) is arranged between the inner stator (230) and the outer stator (220) in a radial direction (202) of the motor shaft (250), a first winding (225) for operation at a first voltage level is assigned to the outer stator (220), and a second winding (235) for operation at a second voltage level is assigned to the inner stator (230), and the first and second voltage levels are different from each other.

Description

[Technical Field]

[0001] The present invention relates to a drive motor for a power tool that drives a tool receiving portion of the power tool. [Background technology]

[0002] In the prior art, drive motors for power tools are known which comprise a rotor and a stator arranged on the motor shaft. Summary of the Invention

[0003] The present invention relates to a drive motor for a power tool, which drives a tool holder of the power tool, and includes a rotor, an inner stator, and an outer stator arranged on a motor shaft, the rotor being arranged radially between the inner and outer stators, the outer stator being assigned a first winding for operation at a first voltage level, and the inner stator being assigned a second winding for operation at a second voltage level, the first and second voltage levels being different from each other.

[0004] The invention thereby makes it possible to provide a drive motor which can be operated at different voltage levels simply by arranging the rotor between an inner stator and an outer stator.

[0005] During operation of the drive motor, preferably, either the inner stator or the outer stator is energized.

[0006] This may allow for easy and simple operation at the first or second voltage level.

[0007] Preferably, the inner stator is configured as a DC stator and the outer stator is configured as an AC stator.

[0008] This allows for easy operation with either DC or AC.

[0009] Preferably, in the network operating mode the outer stator is energized at a first voltage level, in particular the network voltage, and the inner stator is not energized.

[0010] This may allow for reliable and secure operation at network voltage.

[0011] Preferably, in the battery operating mode, the inner stator is energized at a second voltage level, in particular the battery voltage, and the outer stator is not energized.

[0012] This may allow for reliable and reliable operation at battery voltage.

[0013] The motor shaft is preferably assigned a decoupling mechanism which decouples the inner stator or the outer stator, respectively, in the de-energized state.

[0014] This makes it possible to simply operate at network voltage or battery voltage.

[0015] Preferably, the rotor is assigned a magnet carrier, which has, on its outer periphery, a first magnet unit assigned to the outer stator and, on its inner periphery, a second magnet unit assigned to the inner stator.

[0016] This may provide a compact rotor that may be operated in combination with an outer or inner stator.

[0017] Preferably, the inner stator and the outer stator are arranged coaxially with each other.

[0018] This allows for easy and simple suitable arrangement of the inner stator and the outer stator.

[0019] The invention further relates to a power tool, in particular a hand tool machine, comprising a drive motor as described above.

[0020] The present invention thereby makes it possible to provide an electric tool, in particular a hand tool machine, with a drive motor that can be easily operated at different voltage levels by arranging the rotor between an inner stator and an outer stator.

[0021] The invention will be explained in more detail in the following description on the basis of an embodiment shown in the drawing. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic view of a power tool configured as a hand tool machine and equipped with a drive motor according to the invention; [Figure 2] 2 is a schematic diagram of the drive motor according to the present invention of FIG. 1; DETAILED DESCRIPTION OF THE INVENTION

[0023] In the figures, elements having the same or comparable function are given the same reference numerals and are described in detail only once.

[0024] 1 shows a power tool 100, exemplarily configured as a hand tool machine, which illustratively comprises a housing 105 having a hand grip 115. According to one embodiment, the power tool 100 is mechanically and electrically connectable to a battery pack 190 for a network-independent current supply and is provided with a current cable 180 for a network-dependent current supply. The power tool 100 can then be operated either network-independently or network-dependently.

[0025] Preferably, the power tool 100 is provided with a tool receiving portion 140 for receiving an insert tool, such as a driver bit, a drill, etc. However, it should be noted that the present invention is not limited to hand tool machines, such as drivers, hammer drills, impact drivers, saws, circular saws, etc., and the power tool 100 may also be formed as a garden tool, an electric bicycle, etc.

[0026] Arranged within the housing 105 is a drive unit 127 illustratively having at least one electric drive motor 120. Exemplarily, the drive unit 127 is assigned an optional transmission mechanism 130.

[0027] The drive motor 120 is preferably configured to drive the tool receiving portion 140 and, therefore, an insert tool disposed within the tool receiving portion 140. In this case, the drive motor 120 may be switchable on and off, for example, via a hand switch 195.

[0028] 2 shows the drive motor 120 of FIG. 1, which includes a rotor 210 arranged on a motor shaft 250, an outer stator 220, and an inner stator 230. Preferably, the inner stator 230 and the outer stator 220 are arranged coaxially with each other. In this case, the rotor 210 is arranged between the inner stator 230 and the outer stator 220 in the radial direction of the motor shaft 250 or in the radial direction 202 of the drive motor 120.

[0029] The rotor 210 is preferably disposed inside the outer stator 220 in the radial direction 202. Furthermore, the inner stator 230 is disposed inside the rotor 210 in the radial direction 202. In particular, the rotor 210 is disposed directly between the inner peripheral portion 221 of the outer stator 220 and the outer peripheral portion 231 of the inner stator 230 in the radial direction 202.

[0030] According to the present invention, the outer stator 220 is assigned a first winding 225 for operation at a first voltage level, and the inner stator 230 is assigned a second winding 235 for operation at a second voltage level, the first and second voltage levels being different from each other.

[0031] Preferably, the inner stator 230 is formed as a DC stator and the outer stator 220 is formed as an AC stator, but the inner stator 230 may be formed as an AC stator and the outer stator 220 may be formed as a DC stator.

[0032] During operation of the drive motor 120, preferably the inner stator 230 or the outer stator 220 is energized, which may allow for hybrid DC-AC operation.

[0033] Preferably, in the network operation mode, the outer stator 220 is energized at a first voltage level, in particular the network voltage, via the current cable 180 in Fig. 1, and the inner stator 230 is not energized. In the battery operation mode, preferably, the inner stator 230 is energized at a second voltage level, in particular the battery voltage, via the battery pack 190 in Fig. 1, and the outer stator 220 is not energized. In this case, for example, the corresponding battery voltage can be assigned a voltage level of 36 V, and the corresponding network voltage can be assigned a voltage level of, for example, 230 V.

[0034] Preferably, a magnet carrier 212 is assigned to the rotor 210. The magnet carrier 212 preferably has a first magnet unit 214 assigned to an outer stator 220 at an outer periphery 211 of the magnet carrier 212, and a second magnet unit 216 assigned to an inner stator 230 at an inner periphery 213 of the magnet carrier 212.

[0035] According to one embodiment, a decoupling mechanism is assigned to the motor shaft 250, which decouples the inner stator 230 or the outer stator 220 when they are not energized, thereby preventing braking of the rotor 210 by the stators when they are not energized and running idle. [Explanation of symbols]

[0036] 100 Power Tools 105 Housing 115 Hand Grip 120 drive motor 127 Drive Unit 130 Transmission Mechanism 140 Tool holder 180 Current Cable 190 Battery Pack 195 Hand Switch 202 Radial 210 rotor 211 (Magnet carrier) outer periphery 212 Magnet Carrier 213 (Magnet carrier) inner circumference 214 First Magnet Unit 216 Second Magnet Unit 220 outer stator 221 (outer stator) inner circumference 225 First Winding 230 Inner Stator 231 (inner stator) outer periphery 235 Second Winding 250 motor shaft

Claims

1. A drive motor (120) for a power tool (100) that drives a tool receiving portion (140) of the power tool (100), comprising: a rotor (210) disposed on a motor shaft (250); an inner stator (230); an outer stator (220); Equipped with The rotor (210) is disposed between the inner stator (230) and the outer stator (220) in a radial direction (202) of the motor shaft (250), The outer stator (220) is assigned a first winding (225) for operation at a first voltage level, and the inner stator (230) is assigned a second winding (235) for operation at a second voltage level; the first and second voltage levels are different from each other; A drive motor for an electric tool that drives a tool receiving portion of the electric tool, characterized in that:

2. 2. The drive motor according to claim 1, wherein the inner stator (230) or the outer stator (220) is energized during operation of the drive motor (120).

3. 3. A drive motor according to claim 1 or 2, characterized in that the inner stator (230) is configured as a DC stator and the outer stator (220) is configured as an AC stator.

4. 4. A drive motor according to claim 1, wherein in a network operating mode the outer stator (220) is energized with the first voltage level, in particular the network voltage, and the inner stator (230) is not energized.

5. 5. A drive motor according to claim 1, wherein in a battery operating mode, the inner stator (230) is energized at the second voltage level, in particular the battery voltage, and the outer stator (220) is not energized.

6. 6. The drive motor according to claim 1, wherein the motor shaft (250) is provided with a decoupling mechanism that decouples the inner stator (230) or the outer stator (220) in a non-energized state.

7. 7. A drive motor according to claim 1, characterized in that the rotor (210) is assigned to a magnet carrier (212), the magnet carrier (212) having, on its outer periphery (211) thereof, a first magnet unit (214) assigned to the outer stator (220), and on its inner periphery (213) thereof, a second magnet unit (216) assigned to the inner stator (230).

8. 8. A drive motor according to claim 1, wherein the inner stator (230) and the outer stator (220) are arranged coaxially with each other.

9. A power tool (100), in particular a hand tool machine, comprising a drive motor (120) according to any one of claims 1 to 8.

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