Electric Motor For A Small Electric Device

• US 20120119596A1
• Filed: 01/25/2012
• Published: 05/17/2012
• Est. Priority Date: 06/12/2009
• Status: Active Grant

• Current Assignee: Braun GmbH (The Procter & Gamble Company)
• Original Assignee: Braun GmbH (The Procter & Gamble Company)
• Inventors: Doll, Alexander, Schober, Uwe, Kressmann, Frank
• Granted Patent: US 8,994,235 B2
• Time in Patent Office: Days
• US Class Current: 310/36
• CPC Class Codes: H02K 16/02 Machines with one stator and two or more rotors
• CPC Class Codes: H02K 21/28 with armatures rotating within the magnets
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 33/02 with armatures moved one way by energisation of a single coil system and returned by mechanical force, e.g. by springs
• CPC Class Codes: H02K 41/0356 moving along a straight path

Abstract

An electric motor for operating a small electric device is disclosed. The electric motor includes at least one first oscillatory motor component; an inductor for producing a magnetic field; and a first magnet arrangement including a first permanent magnet that generates a force for activating a rotatory oscillating movement (R) of the at least one first oscillatory motor component around a rotating axis (z). The at least one first oscillatory motor component and the first magnet arrangement are configured such that a magnetic reluctance torque acting between the first oscillatory motor component and the first permanent magnet operates as a righting moment for the rotatory oscillating movement (R).

Claims

1. An electric motor for operating a small electric device, comprising:

at least one first oscillatory motor component;

an inductor for producing a magnetic field; and

a first magnet arrangement including a first permanent magnet that generates a force for activating a rotatory oscillating movement (R) of the at least one first oscillatory motor component around a rotating axis (z);

wherein the at least one first oscillatory motor component and the first magnet arrangement are configured such that a magnetic reluctance torque acting between the first oscillatory motor component and the first permanent magnet operates as a righting moment for the rotatory oscillating movement (R).

2. The electric motor according to claim 1, wherein the at least one first oscillatory motor component and the first magnet arrangement are configured such that the magnetic reluctance torque is a linear function of the deflection angle below a maximum deflection angle, at least in one area of the deflection angle of the first oscillatory component.

3. The electric motor according to claim 1, wherein the first oscillatory motor component has a rotor that is allocated to the first magnet arrangement, and a rotor aperture angle (a) of the rotor and a magnet segment angle (b) of the first permanent magnet are chosen so that when the electric motor is running, an essentially linear course of the reluctance torque is achieved between the rotor and the first magnet arrangement up to the chosen maximum deflection angle.

4. The electric motor according to claim 1, further comprising at least one second oscillatory motor component and a second magnet arrangement including a second permanent magnet configured to generate a force for activating a translatory oscillating movement (L) of the at least one second oscillatory motor component.

5. The electric motor according to claim 4, wherein the second magnet arrangement interacts with a magnetic field produced with by the inductor in order to generate a force for activating a translatory oscillating movement (L) of the at least one first oscillatory motor component.

6. The electric motor according to claim 4, wherein the translatory oscillating movement (L) is perpendicular to the rotating axis (z) of the rotatory oscillating movement (R).

7. The electric motor according to claim 6, wherein the translatory (L) and the rotatory (R) oscillating movements have different resonance frequencies.

8. The electric motor according to claim 4, wherein the permanent magnets of the first and the second magnet arrangement move with the first oscillatory motor component.

9. The electric motor according to claim 1, wherein the first magnet arrangement includes several permanent magnets arranged coaxially to the first oscillatory component.

10. The electric motor according to claim 4, wherein the second magnet arrangement includes several permanent magnets that are connected in at least one axial direction to the permanent magnets of the first magnet arrangement.

11. The electric motor according to claim 1, further comprising at least one flux guiding element.

12. The electric motor according to claim 1, wherein the axis of the at least one inductor and the rotating axis (z) of the rotatory oscillating movement (R) are perpendicular to each other.

13. The electric motor according to claim 1, wherein the axis of the at least one inductor and the rotating axis (z) of the rotatory oscillating movement (R) are parallel to each other.

14. The electric motor according to claim 4, wherein the first and second magnet arrangements in the direction of axis of the at least one inductor are arranged on different sides of the inductor.

15. A small electric device having an electric motor according to claims 1.