Drive motor and power tool having a drive motor

Abstract

In a drive motor (120) for a power tool for driving a tool holder of the power tool, having a rotor (210) arranged on a motor shaft (250), an inner stator (230) and an outer stator (220), the rotor (210) is arranged in the radial direction (202) of the motor shaft (250) between the inner stator (230) and the outer stator (220), wherein a first winding (225) for operation using a first voltage level is assigned to the outer stator (220) and a second winding (235) for operation using a second voltage level is assigned to the inner stator (230), and wherein the first and second voltage levels are different from one another.

Description

[0001] Description

[0002] title

[0003] Drive motor and power tool with a drive motor

[0004] State of the art

[0005] The present invention relates to a drive motor for a power tool for driving a tool holder of the power tool.

[0006] A drive motor for a power tool is known from the prior art, which has a rotor and a stator arranged on a motor shaft.

[0007] Disclosure of the invention

[0008] The invention relates to a drive motor for a power tool for driving a tool holder of the power tool. A rotor arranged on a motor shaft, an inner stator, and an outer stator are provided, wherein the rotor is arranged between the inner stator and the outer stator in the radial direction of the motor shaft. A first winding for operation at a first voltage level is assigned to the outer stator, and a second winding for operation at a second voltage level is assigned to the inner stator, and wherein the first and second voltage levels differ from one another.

[0009] The invention thus enables the provision of a drive motor in which, by arranging the rotor between the inner stator and the outer stator, operation at different voltage levels can be easily enabled. During operation of the drive motor, the inner stator or the outer stator is preferably energized.

[0010] This makes it easy and straightforward to operate with the first or second voltage level.

[0011] Preferably, the inner stator is designed as a direct current stator and the outer stator as an alternating current stator.

[0012] This makes it easy to operate with direct current or alternating current.

[0013] Preferably, in a mains operating mode, the outer stator is energized with the first voltage level, in particular a mains voltage, and the inner stator is de-energized.

[0014] This enables safe and reliable operation with mains voltage.

[0015] Preferably, in a battery operating mode, the inner stator is energized with the second voltage level, in particular a battery voltage, and the outer stator is de-energized.

[0016] This enables safe and reliable operation with one battery voltage.

[0017] The motor shaft is preferably assigned a decoupling mechanism for decoupling the inner stator or the outer stator in the de-energized state.

[0018] This makes it easy to operate either with mains voltage or with battery voltage.

[0019] Preferably, the rotor is assigned a magnet carrier which has a first magnet unit assigned to the outer stator on its outer circumference and a second magnet unit assigned to the inner stator on its inner circumference.

[0020] Thus, a compact rotor can be provided that can be operated in combination with either the outer stator or the inner stator.

[0021] Preferably, the inner stator and the outer stator are arranged coaxially to each other.

[0022] This makes it easy and uncomplicated to arrange the inner stator and the outer stator in a suitable manner.

[0023] Furthermore, the present invention relates to a power tool, in particular a hand-held power tool, with a drive motor as described above.

[0024] The invention thus enables the provision of a power tool, in particular a hand-held power tool, with a drive motor in which operation with different voltage levels can be enabled in a simple manner by arranging the rotor between the inner stator and the outer stator.

[0025] Short description of the drawings

[0026] The invention is explained in more detail in the following description using exemplary embodiments illustrated in the drawings. They show:

[0027] Fig. 1 is a schematic view of a power tool designed as a hand-held power tool with a drive motor according to the invention, and

[0028] Fig. 2 is a schematic view of the drive motor according to the invention from Fig. 1.

[0029] Description of the embodiments In the figures, elements with the same or comparable function are provided with identical reference symbols and are described in more detail only once.

[0030] Fig. 1 shows a power tool 100, embodied as a handheld power tool, illustratively comprising a housing 105 with a handle 115. According to one embodiment, the power tool 100 is mechanically and electrically connectable to a battery pack 190 for a mains-independent power supply and has a power cable 180 for a mains-dependent power supply. The power tool 100 can be operated either mains-independently or mains-dependently.

[0031] Preferably, the power tool 100 is associated with a tool holder 140 for receiving an insert tool, e.g., a screwdriver bit, a drill, etc. However, it should be noted that the present invention is not limited to handheld power tools, such as screwdrivers, hammer drills, impact wrenches, saws, circular saws, etc., but the power tool 100 can also be configured as a garden tool, electric bicycle, etc.

[0032] A drive unit 127 with at least one electric drive motor 120 is illustratively arranged in the housing 105. An optional transmission 130 is assigned to the drive unit 127, for example.

[0033] The drive motor 120 is preferably designed to drive the tool holder 140 and thus an insert tool arranged therein. The drive motor 120 can be switched on and off, for example, via a manual switch 195.

[0034] Fig. 2 shows the drive motor 120 of Fig. 1 with a rotor 210 arranged on a motor shaft 250, as well as with an outer stator 220 and an inner stator 230. Preferably, the inner stator 230 and the outer stator 220 are arranged coaxially with one another. 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.

[0035] The rotor 210 is preferably arranged within the outer stator 220 in the radial direction 202. Furthermore, the inner stator 230 is arranged within the rotor 210 in the radial direction 202. In particular, the rotor 210 is arranged in the radial direction 202, illustratively, directly between an inner circumference 221 of the outer stator 220 and an outer circumference 231 of the inner stator 230.

[0036] According to the invention, the outer stator 220 is assigned a first winding 225 for operation at a first voltage level. The inner stator 230 is assigned a second winding 235 for operation at a second voltage level. The first and second voltage levels differ from one another.

[0037] Preferably, the inner stator 230 is designed as a direct current stator and the outer stator 220 as an alternating current stator. However, the inner stator 230 can also be designed as an alternating current stator and the outer stator 220 as a direct current stator.

[0038] During operation of the drive motor 120, either the inner stator 230 or the outer stator 220 is preferably energized. This enables hybrid DC / AC operation.

[0039] Preferably, in a mains operating mode, the outer stator 220 is supplied with the first voltage level, in particular a mains voltage, via the power cable 180 of Fig. 1, and the inner stator 230 is de-energized. In a battery operating mode, the inner stator 230 is preferably supplied with the second voltage level, in particular a battery voltage, via the battery pack 190 of Fig. 1, and the outer stator 220 is de-energized. For example, a corresponding battery voltage can be assigned a voltage level of 36 V, and a corresponding mains voltage can be assigned a voltage level of 230 V, for example.

[0040] Preferably, a magnet carrier 212 is assigned to the rotor 210. The magnet carrier 212 preferably has a first magnet unit 214 assigned to the outer stator 220 on its outer circumference 211, and a second magnet unit 216 assigned to the inner stator 230 on its inner circumference 213. According to one embodiment, the motor shaft 250 is assigned a decoupling mechanism for decoupling the inner stator 230 or the outer stator 220 in the de-energized state. This can prevent braking of the rotor 210 by the de-energized stator operating at idle.

Claims

Claims 1. Drive motor (120) for a power tool (100) for driving a tool holder (140) of the power tool (100), characterized by a rotor (210) arranged on a motor shaft (250), an inner stator (230) and an outer stator (220), wherein the rotor (210) is arranged in the radial direction (202) of the motor shaft (250) between the inner stator (230) and the outer stator (220), wherein a first winding (225) for operation with a first voltage level is assigned to the outer stator (220) and a second winding (235) for operation with a second voltage level is assigned to the inner stator (230), and wherein the first and second voltage levels differ from one another.

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

3. Drive motor according to claim 1 or 2, characterized in that the inner stator (230) is designed as a direct current stator and the outer stator (220) is designed as an alternating current stator.

4. Drive motor according to one of the preceding claims, characterized in that in a mains operating mode, the outer stator (220) is energized with the first voltage level, in particular a mains voltage, and the inner stator (230) is de-energized.

5. Drive motor according to one of the preceding claims, characterized in that in a battery operating mode, the inner stator (230) is energized with the second voltage level, in particular a battery voltage, and the outer stator (220) is de-energized.

6. Drive motor according to one of the preceding claims, characterized in that the motor shaft (250) is assigned a decoupling mechanism for decoupling the inner stator (230) or the outer stator (220) in the respective de-energized state.

7. Drive motor according to one of the preceding claims, characterized in that the rotor (210) is assigned a magnet carrier (212) which has on its outer circumference (211) a first magnet unit (214) assigned to the outer stator (220), and on its inner circumference (213) a second magnet unit (216) assigned to the inner stator (230).

8. Drive motor according to one of the preceding claims, characterized in that the inner stator (230) and the outer stator (220) are arranged coaxially to one another.

9. Power tool (100), in particular hand-held power tool, with a drive motor (120) according to one of the preceding claims.

Images