Control device for an electric motor

• US 20040112616A1
• Filed: 09/24/2003
• Published: 06/17/2004
• Est. Priority Date: 03/24/2001
• Status: Active Grant

• Current Assignee: Chiron SRL (GSK plc), Marquardt GmbH (J U J Marquardt KG)
• Original Assignee: Chiron SRL (GSK plc)
• Inventors: Broghammer, Peter, Hafen, Daniel
• Granted Patent: US 7,359,628 B2
• Time in Patent Office: Days
• US Class Current: 173/217
• CPC Class Codes: B25F 5/008 Cooling means
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: Y10S 388/937 Hand tool

Abstract

The invention relates to a drive device (1) for an electric motor, in particular for a brushless DC motor in an electrical tool which is powered by a rechargeable battery. The drive device (1) has at least one power semiconductor (3), in particular for controllable application of an electrical voltage to the electric motor, a control circuit (4) for controlling the power semiconductor (3), and a mounting plate (2) which, for example, is in the form of a printed circuit board. At least one portion of the control circuit (4), in particular electrical and/or electronic components (5) as well as the conductor tracks (6) (which connect the electrical and/or electronic components (5)) of the control circuit (4), is arranged on the mounting plate (2). The power semiconductor (3) is arranged on the mounting plate (2) and/or on a mount element (7) which is mounted on the mounting plate (2).

Claims

1. A device for driving an electric motor (23), in particular a brushless DC motor in an electrical tool which is powered by a rechargeable battery, having at least one power semiconductor (3), in particular for controllable application of an electrical voltage to the electric motor (23), having a control circuit (4) for controlling the power semiconductor (3), and having a mounting plate (2), in particular a printed circuit board, with at least a portion of the control circuit (4), in particular electrical and/or electronic components (5) as well as the conductor tracks (6) (which connect the electrical and/or electronic components (5)) of the control circuit (4), being arranged on the mounting plate (2), and with the power semiconductor (3) being arranged on the mounting plate

and/or on a mount element (7) which is mounted on the mounting plate (2).

6. The device for driving an electric motor (23) as claimed in one of claims 1 to 5, characterized in that two or more power semiconductors (3), in particular two or more MOSFETs, for example six MOSFETs, are arranged on the mount element (7) or on the mounting plate (2).

7. The device for driving an electric motor (23) as claimed in one of claims 1 to 6, characterized in that the mount element (7) for the power semiconductor (3) is in the form of a heat sink, with the mount element (7) being arranged in particular such that it projects approximately vertically from the mounting plate (2), and with the mount element (7) preferably being pressed and/or soldered into the mounting plate (2).

8. The device for driving an electric motor (23) as claimed in one of claims 1 to 7, characterized in that a rechargeable battery is used for supplying voltage to the electric motor (23), and in that the mounting plate (2) is arranged in the vicinity of the rechargeable battery, in particular such that the power semiconductor (3) and/or the mount element (7) together with the power semiconductor (3) face/faces the rechargeable battery.

9. The device for driving an electric motor (23) as claimed in one of claims 1 to 8, characterized in that plug contacts (11), which are in particular in the form of contact brackets [sic], for example “

tulip”

brackets [sic], are arranged on the mounting plate (2) in order to make plug-in contact with the rechargeable battery, in which case the plug contacts (11) can preferably be plugged and/or latched onto the mounting plate (2), in particular by means of an adapter (12).

10. The device for driving an electric motor (23) as claimed in one of claims 1 to 9, characterized in that the power semiconductor (3) and/or the mount element (7) for the power semiconductor (3) are/is arranged directly on that edge (13) of the mounting plate (2) which faces the rechargeable battery, with the power semiconductor (3) and/or the mount element (7) preferably making direct electrical contact with the plug contacts (11) for the rechargeable battery, with the plug contacts (11) furthermore preferably being integrated integrally in the mounting plate (2) and/or in the mount element (7), and with capacitors (14) of the control circuit (4) furthermore preferably being soldered directly to the plug contact (11).

11. The device for driving an electric motor (23) as claimed in one of claims 1 to 10, characterized in that capacitors (14) of the control circuit (4) are arranged on the mounting plate (2), in particular with the capacitors (14) being located between the power semiconductor (3) and/or the mount element (7) for the power semiconductor (3) and the plug contacts (11).

12. The device for driving an electric motor (23) as claimed in one of claims 1 to 11, characterized in that a sensor element (15), such as a potentiometer, a Hall element, a magnetoresistive element or the like, is located on the mounting plate (2) in order to produce a nominal value, which is in turn supplied to the control circuit (4) in order to set an associated rotation speed for the electric motor (23), with the sensor element (15) preferably being arranged in a housing (17) of an electrical switch (16), and with an operating member (18), which in particular is in the form of a push button, for the sensor element (15) furthermore preferably being arranged on the housing (17) of the switch (16).

13. The device for driving an electric motor (23) as claimed in one of claims 1 to 12, characterized in that a contact system (19), which is used in particular for switching the voltage supply for the electric motor (23) and, possibly, for the control circuit (4), is arranged in the electrical switch (16), in which case the contact system (19) can preferably be operated by means of the operating member (18).

14. The device for driving an electric motor (23) as claimed in one of claims 1 to 13, characterized in that a further electrical switch (20), in particular a microswitch and/or a snap-action switch, is arranged on the mounting plate (2), with an operating element (21), which is, in particular, in the form of a slide for switching the electric motor (23) between clockwise running and counterclockwise running, acting on the further switch (20).

15. An electrical tool having a handle shell (25), with a device (1) as claimed in one of the preceding claims being arranged in the handle shell (25) such that the operating member (18) projects out of the handle shell (25) for manual operation.

16. An electrical tool having a handle shell (25), with a device (1) as claimed in one of the preceding claims being arranged in the rechargeable battery such that, once the rechargeable battery has been inserted into the handle shell (25) of the electrical tool (22), the operating member (18) projects out of the handle shell, and/or the operating member (18) which is already located in the handle shell (25) is articulated on the device (1).

2. A device for driving an electric motor (23), in particular a brushless DC motor in an electrical tool which is powered by a rechargeable battery, having at least one power semiconductor (3), in particular for controllable application of an electrical voltage to the electric motor (23), having a control circuit (4) for controlling the power semiconductor (3), and having a mounting plate (2), with at least a portion of the control circuit (4), in particular electrical and/or electronic components (5) as well as the conductor tracks (6) (which connect the electrical and/or electronic components (5)) of the control circuit (4), being arranged on the mounting plate (2), with the mounting plate (2) comprising a metal part (9), whose surface which faces the components (5) and the conductor tracks (6) is provided with an insulating coating (8), such that the components (5), the conductor tracks (6) or the like are themselves located on the coating (8), and such that the metal part (9) is at the same time used as a heat sink.

3. The device for driving an electric motor (23) as claimed in claim 2, characterized in that the power semiconductor (3) is arranged on the coating (8) on the metal part (9).

4. The device for driving an electric motor (23) as claimed in claim 2, characterized in that the coating (8) contains a cutout (10), and in that the power semiconductor (3′

) is mounted directly on the metal part (9), on the cutout (10), in particular being soldered onto it.

5. The device for driving an electric motor (23) as claimed in claim 2, characterized in that the power semiconductor (3) is arranged on a mount element (7), and in that the mount element (7) is mounted on the mounting plate (2).