Electric motor for a small-scale electrical appliance

• US 20060255665A1
• Filed: 05/25/2006
• Published: 11/16/2006
• Est. Priority Date: 11/27/2003
• Status: Active Grant

• Current Assignee: Braun GmbH (The Procter & Gamble Company)
• Original Assignee: Braun GmbH (The Procter & Gamble Company)
• Inventors: Schober, Uwe, Kraus, Bernhard, Reick, Hansjorg, Schroter, Alexander
• Granted Patent: US 7,554,225 B2
• Time in Patent Office: Days
• US Class Current: 310/36
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 33/18 with coil systems moving upon intermittent or reversed energisation thereof by interaction with a fixed field system, e.g. permanent magnets

Abstract

An electric motor for a small-scale electrical appliance, such as a toothbrush or shaver. The electric motor includes at least one oscillatory motor component, a magnet arrangement having at least one permanent magnet, and a coil for generating a magnetic field which, in interaction with the magnet arrangement, generates a force for excitation of an oscillatory linear motion. During the interaction between the magnet arrangement and the magnetic field produced by the coil, a torque for excitation of an oscillatory rotational motion is additionally generated.

Claims

1. An electric motor for a small-scale electrical appliance comprising:

at least one oscillatory motor component;

a magnet arrangement having at least one permanent magnet; and

a coil arranged to generate a magnetic field that interacts with the magnet arrangement to generate a force for excitation of an oscillatory linear motion, wherein interaction between the magnet arrangement and the magnetic field produced by the coil generates a torque for excitation of an oscillatory rotational motion in addition to the linear motion.

2. The electric motor according to claim 1, wherein the oscillatory rotational motion defines a rotational axis that is parallel to the oscillatory linear motion.

3. The electric motor according to claim 1 wherein the oscillatory rotational motion defines a rotational axis that is perpendicular to the oscillatory motion.

4. The electric motor according to claim 1, wherein the oscillatory motor component performs a plurality of different oscillatory motions.

5. The electric motor according to claim 1, further comprising a plurality of motor components, each performing at least one oscillatory motion.

6. The electric motor according to claim 5, wherein the oscillatory motor components execute oscillatory motions in phase opposition to each other.

7. The electric motor according to claim 5, wherein the motor components perform different oscillatory motions.

8. The electric motor according to claim 7, wherein one motor component performs a linear oscillation, and another motor component performs a rotational oscillation.

9. The electric motor according to claim 1, wherein each of one set of permanent magnets excites one type of oscillatory motion.

10. The electric motor according to claim 1, further comprising a plurality of functional segments arranged axially side-by-side, with each functional segment having one set of permanent magnets.

11. The electric motor according to claim 10, wherein at least one outer functional segment arranged in an axial end area includes one set of permanent magnets for excitation of an oscillatory linear motion.

12. The electric motor according to claim 11, wherein at least one inner functional segment arranged axially between two outer functional segments includes one set of permanent magnets for excitation of an oscillatory rotational motion.

13. The electric motor according to claim 1, further comprising a rotor and a stator constructed as oscillatory motor components.

14. The electric motor according to claim 1, further comprising an elastic element;

and at least one balancing weight coupled by the elastic element to the oscillatory motor component.

15. The electric motor according to claim 14, wherein the balancing weight oscillates in phase opposition to the oscillatory motor component.

16. The electric motor according to claim 1, further comprising a plurality of oscillatory motor components with different resonant frequencies.

17. The electric motor according to claim 1, further comprising an elastic element configured to tap the motion the oscillatory motor component.

18. The electric motor according to claim 1, further comprising a magnetizable material within at least part of the coil and configured to be temporarily magnetized by the magnetic field of the coil.

19. A small-scale electrical appliance comprising a housing and the electric motor of claim 1 disposed within the housing.

20. The small-scale electrical appliance according to claim 19, constructed as an electric toothbrush.

21. The small-scale electrical appliance according to claim 19, constructed as an electric shaving apparatus.

22. A method of operating an electric motor having at least one oscillatory motor component, the method comprising:

generating a force for excitation of an oscillatory linear motion of a motor component by inducing a magnetic field in a coil, the magnetic field interacting with a magnet arrangement having at least one permanent magnet; and

generating a torque for excitation of an oscillatory rotational motion through interaction of the magnetic field and the magnet arrangement.

23. The method according to claim 22, wherein different oscillatory motor components are excited into oscillations having different frequencies and/or amplitudes.