Timepiece mechanism provided with a magnetic gear

Patent metadata

Field	Value
Publication number	US-12353169-B2
Application number	US-202217869273-A
Country	US
Kind code	B2
Filing date	Jul 20, 2022
Priority date	Aug 30, 2021
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A mechanism ( 1 ) including a magnetic gear ( 2 ) including a first wheel ( 6 B) and a second wheel ( 6 C) provided with a first magnetic toothing ( 10 ) and a second magnetic toothing ( 12 ) respectively. The first and second magnetic toothings are respectively formed by first and second teeth made of a soft ferromagnetic material; and the magnetic gear ( 2 ) further includes a third wheel ( 6 A) arranged between the first and second wheels ( 6 B, 6 C) and provided with a third magnetic toothing ( 8 ) formed by permanent magnetic poles, in particular by bipolar magnets. In general, the first wheel is a drive wheel, whereas the second wheel is driven into order to carry out a function or transmit a torque. The third intermediate wheel is preferably mounted such that it can rotate freely.

First claim

The invention claimed is:

1. A timepiece mechanism, comprising a magnetic gear including a first wheel and a second wheel provided with a first magnetic toothing and a second magnetic toothing respectively;
wherein the first and second magnetic toothings are respectively formed by first and second teeth made of a soft ferromagnetic material; and
wherein the magnetic gear further comprises a third wheel arranged between the first and second wheels and provided with first permanent magnetic poles forming the magnetised teeth of a third magnetic toothing comprised in the third wheel and which is configured in such a way that first magnetic fluxes, having alternating polarities, emerge respectively from the magnetised teeth, the third wheel and the first wheel being arranged in such a way that the third magnetic toothing has a first magnetic coupling with the first magnetic toothing generated by said first magnetic fluxes which momentarily polarise, in magnetic attraction, teeth of the first magnetic toothing, momentarily located in a first magnetic coupling zone with the third magnetic toothing and through which first magnetic fluxes from among said first magnetic fluxes respectively flow, the third wheel and the second wheel being arranged in such a way that the third magnetic toothing or a fourth magnetic toothing, which is comprised by the third wheel and which is formed by second permanent magnetic poles from which second magnetic fluxes emerge with alternating polarities, has a second magnetic coupling with the second magnetic toothing, which is generated by said first magnetic fluxes, or respectively by said second magnetic fluxes, which momentarily polarise, in magnetic attraction, teeth of the second magnetic toothing which are momentarily located in a second magnetic coupling zone with the third magnetic toothing or with the fourth magnetic toothing and through which first magnetic fluxes from among said first magnetic fluxes flow, or respectively though which second magnetic fluxes from among said second magnetic fluxes flow.

2. The mechanism according to claim 1 , wherein the third wheel is mounted such that it can rotate freely, the third wheel being configured to transmit a torque received from the first wheel, which is a drive wheel in the magnetic gear, to the second wheel which is driven by the first wheel via the third wheel so as to carry out a function of the mechanism or to transmit within the mechanism a torque received from the first wheel.

3. The mechanism ( 1 ) according to claim 1 , wherein the first magnetic toothing comprises N1 teeth, the second magnetic toothing comprises N2 teeth, and the third magnetic toothing comprises N3 teeth; wherein the number N3 is an even number between four and ten, inclusive; and wherein the ratio between the number N1 and the number N3, and the ratio between the number N2 and the number N3, are each greater than or equal to two.

4. The mechanism ( 1 ) according to claim 1 , wherein the third wheel has a central part made of a ferromagnetic material, on the periphery whereof its said permanent magnetic poles are arranged in pairs respectively with as many complementary magnetic poles, forming bipolar magnets having radial magnetisation and respectively defining the magnetised teeth of the third magnetic toothing.

5. The mechanism according to claim 1 , wherein the first wheel or the second wheel comprises a rim forming a continuous circular base for the respective magnetic toothing, the rim being made of a soft ferromagnetic material so as to form a closure closing magnetic paths of said magnetic fluxes.

6. The mechanism according to claim 1 , wherein at least the first and second wheels are coplanar.

7. The mechanism according to claim 6 , wherein the first, second and third wheels are coplanar.

8. The mechanism according to claim 1 , wherein at least the first and second wheels extend in separate planes.

9. The mechanism according to claim 8 , wherein each of the first, second and third wheels extend in a separate plane.

10. The mechanism according to claim 9 , wherein the third wheel includes said fourth magnetic toothing, wherein the first and second wheels extend in substantially perpendicular planes, wherein the third wheel extends in a plane disposed at substantially 45 degrees to the plane in which the first wheel extends and to the plane in which the second wheel extends; and wherein each of said first permanent magnetic poles forms, with a corresponding second permanent magnetic pole from among said second permanent magnetic poles, a bipolar magnet having axial magnetisation, the first, second and third wheels being positioned such that the one or more bipolar magnets coupled to the first magnetic toothing are simultaneously coupled to the second magnetic toothing ( 12 ).

11. The mechanism according to claim 10 , wherein the first wheel and the second wheel each comprise a rim forming a continuous circular base respectively for the first magnetic toothing and the second magnetic toothing, the rim being made of a soft ferromagnetic material so as to form a closure closing magnetic paths respectively of said first magnetic fluxes and of said second magnetic fluxes.

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Imboden Matthias
• Mignot Jean-Pierre
• Calic Milan
• Nicolas Cédric
• Born Jean-Jacques

Classifications

• G04B13/02 Primary

  Wheels; Pinions; Spindles; Pivots (bearings G04B31/00 {; chain wheels, spindles for chain wheels, also chains and driving weights G04B1/08}) · CPC title

• H02K49/102

  Magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without physical contact (magnetized gearings with physical contact F16H13/12, F16H49/005) · CPC title

• G04B11/005 Primary

  with magnetic elements · CPC title