Timekeeping mechanism with magnetic gears

Abstract

The mechanism includes a magnetic gear (2), which comprises a first gear (6A), a second gear (6B), and a third gear (6C). The first gear is provided with permanent magnet poles (7) arranged to form magnetized teeth of a first magnetic gear system (8). The second and third gears are provided with teeth made of soft ferromagnetic material that define a second magnetic gear system (10) and a third magnetic gear system (12), respectively. The second magnetic gear system (10) and the third magnetic gear system (12) each have a greater number of teeth than the first magnetic gear system (8) and are magnetically coupled to the first magnetic gear system. With the magnetic flux provided by the magnetized teeth of the first gear system and because the teeth of the second magnetic gear system are magnetically separated from each other, the second magnetic gear system (10) is directly coupled to the first magnetic gear system on the one hand and directly coupled to the third magnetic gear system on the other hand.

Description

Technical Field

[0001] The present invention relates to the field of magnetic gears formed by a first wheel and a second wheel that are magnetically meshed with each other, the first wheel having a first permanent magnet pole arranged in a circular manner and defining the magnetized teeth of a first magnetic gear system.

[0002] In particular, the present invention relates to mechanisms incorporating such magnetic gears, especially timekeeping mechanisms. Background Technology

[0003] Magnetic gears are known devices that can be used to transmit mechanical torque between two components without any direct contact between the components, and therefore without causing wear or friction between them. Such gears offer the following advantages:

[0004] - Since there is no mechanical wear on the teeth of the component, no oil or lubricant is required;

[0005] - Toothed components can interact and transmit torque and mechanical power, even when they are sealed apart; and

[0006] - Toothed components can be used to limit maximum torque and thus help avoid damage, such as in the event of mechanical shock.

[0007] Such magnetic gears typically consist of two wheels that are magnetically meshed with each other. The first wheel has first permanent magnet poles, which are usually alternate and arranged in a circle, defining a first magnetic tooth system. For example, these first magnetic poles are defined by a bipolar magnet with radial and alternating magnetization. The second wheel has teeth or second permanent magnet poles made of ferromagnetic material, which are arranged in a circle and define a second magnetic tooth system. The first and second wheels are usually located in the same general plane. The magnetic coupling between the tooth systems of the first and second wheels means that when one of the first and second wheels is driven to rotate, the other wheel is also driven to rotate.

[0008] However, a drawback of this type of magnetic gear is that it requires at least each tooth of the first gear to be magnetized (by permanent magnetization), typically with alternating polarities, regardless of the diameter and number of teeth in the first gear train. This leads to two significant consequences: firstly, such magnetic gears are expensive to manufacture; and secondly, although the number of teeth in the first gear train involved in the magnetic interaction between the two gears at any given time is relatively small, the other magnets in the first circular gear train will generate magnetic field lines that propagate through the system containing the magnetic gear (typically a timepiece mechanism). However, it is difficult to confine such magnetic field lines to protect other components of the mechanism from the effects caused by these lines, particularly from magnetic attraction that can cause pseudo-mechanical stresses in some moving elements of the mechanism. Such effects can impair the proper operation of the system, especially when the system is a watch movement comprising a set of wheels made of magnetic materials. Summary of the Invention

[0009] Therefore, the present invention aims to overcome the disadvantages of the prior art by providing a mechanism (in particular a timekeeping mechanism) that includes a magnetic gear that is simple and inexpensive to manufacture, and which allows for a reduction in the number of permanent magnet poles required by the magnetic gear, and enables the limitation of magnetic field lines to protect a variety of other components of the system containing the mechanism.

[0010] For this purpose, the present invention relates to a mechanism, particularly a timekeeping mechanism, comprising a magnetic gear including a first wheel and a second wheel. The first wheel is provided with permanent magnet poles arranged to form magnetized teeth of a first magnetic tooth system, from which a first magnetic flux of alternating polarities emanates. The second wheel is provided with teeth made of a soft ferromagnetic material defining a second magnetic tooth system, the number of teeth in the second magnetic tooth system being greater than the number of teeth in the first magnetic tooth system, and having a first magnetic coupling with the first magnetic tooth system such that when one of the first and second wheels is driven to rotate, the other wheel is also driven to rotate, wherein a first transmission ratio is defined by the first and second magnetic tooth systems; the first magnetic coupling is generated, at least in most respects, by magnetic flux from the first magnetic flux, which temporarily polarizes the teeth of the second magnetic tooth system in the form of magnetic attraction, such that these teeth are temporarily located in the magnetic coupling region with the first magnetic tooth system and thus these magnetic fluxes pass through these teeth respectively. According to the invention, the magnetic gear further includes a third wheel having teeth made of a soft ferromagnetic material defining a third magnetic tooth system, the number of teeth in the third magnetic tooth system being greater than the number of teeth in the first magnetic tooth system; a second magnetic tooth system is arranged on a rim made of a non-magnetic material, wherein there are non-magnetic regions between the teeth of the second tooth system; the third wheel is arranged relative to the second wheel in such a way that the temporarily magnetized teeth of the third magnetic tooth system and the second magnetic tooth system have a second magnetic coupling in the magnetic coupling region, such that when one of the second and third wheels is driven to rotate, Another wheel is also driven to rotate, wherein a second gear ratio is defined by the second and third magnetic gear systems; the second magnetic coupling is generated at least in part by a second magnetic flux, which emerges from the temporarily magnetized teeth of the second magnetic gear system having alternating polarities, and temporarily polarizes the teeth of the third magnetic gear system in the form of magnetic attraction, wherein these teeth are located in the magnetic coupling region and therefore the second magnetic flux passes through these teeth respectively; the magnetic coupling region defines the magnetic engagement region for the first, second, and third wheels. The soft ferromagnetic material is preferably a material with high permeability and therefore low magnetic reluctance.

[0011] Such a magnetic gear mechanism, constructed in this way, generates local and temporary magnetization only on the teeth of the second and third gear systems made of soft ferromagnetic material. These teeth are located in the magnetic coupling region and are active at a given moment. The number of permanent magnet poles in the first gear required to generate such local magnetization is thus significantly reduced. This allows for reduced costs and simplified manufacturing of the mechanism, and allows the magnetic field lines near the location where torque transmission occurs between the second and third gears to be confined locally. The teeth made of soft ferromagnetic material present on the second and third gears have a specific arrangement of the second gear system formed by teeth separated from each other and arranged on non-magnetic supports, allowing the closure of the magnetic field lines generated by the permanent magnet poles of the first gear system through the second and third gear systems. This results in magnetic coupling between the second and third gears, and thus magnetic meshing between the two gears.

[0012] In particular, it can better protect various components of the system containing the mechanism (such as, for example, the mechanical movement of a timepiece) from the magnetic field of permanent magnets, which are few in number and therefore can be constrained and magnetic shielding is more easily provided where applicable. Furthermore, such a mechanism according to the invention inherently limits the maximum torque transmitted between the second and third wheels, thereby protecting the gears from damage caused by mechanical shocks.

[0013] Preferably, the first gear includes at least four magnetized teeth. Generally, the first magnetic tooth system includes N1 teeth, the second magnetic tooth system includes N2 teeth, and the third magnetic tooth system includes N3 teeth. Advantageously, the number N1 is an even number between four and ten (including endpoint values); and the ratio between the number N2 and the number N1, and the ratio between the number N3 and the number N1, are each greater than or equal to two, preferably greater than or equal to three. For a finite number of magnets, this improves the efficiency of magnetic coupling between the first, second, and third gears.

[0014] In a general alternative embodiment, each of the second and third wheels includes at least six teeth that extend radially relative to the axis of rotation of the wheel. Each tooth takes the form of a protrusion projecting from the annular periphery of the wheel. In particular, each of the second and third wheels includes between six and thirty teeth that extend radially relative to the axis of rotation of the wheel.

[0015] According to a specific alternative embodiment, the first wheel is also mechanically connected to the second wheel, particularly by means of mechanical gears. This alternative embodiment ensures a permanently optimized alignment between the permanent magnet poles of the first wheel and the teeth of the second wheel made of soft ferromagnetic material, and thus forces the second wheel to precisely follow the rotational movement of the first wheel, and vice versa.

[0016] According to a specific alternative embodiment, the first wheel is mounted such that it can rotate freely. This further alternative embodiment allows for the generation of a first magnetic coupling without friction between the first and second wheels.

[0017] According to a preferred embodiment of the invention, the first wheel is configured such that when projected onto a first plane, the first wheel is within a circle circumscribed around the second wheel, the second wheel extending in the first plane and the first plane being perpendicular to the axis of rotation of the second wheel.

[0018] According to a first alternative of the preferred embodiment, the first wheel is substantially disposed in the first plane and within the second wheel; the second wheel has an annular shape without intersection in the first plane, and the magnetized teeth of the first tooth system are arranged such that a first magnetic flux emerges from these magnetized teeth in the principal radial direction relative to the axis of rotation of the first wheel.

[0019] According to a second alternative of the preferred embodiment, the first wheel is disposed outside the first plane, wherein the axis of rotation of the first wheel is arranged perpendicular to the first plane, and the magnetized teeth of the first tooth system are arranged such that a first magnetic flux emerges from these magnetized teeth in a principal direction that is inclined or parallel to the axis of rotation of the first wheel (axial polarization).

[0020] Advantageously, the first wheel has a central portion made of ferromagnetic material, and the permanent magnet poles of the first wheel are arranged in pairs with an equal number of complementary magnet poles around the periphery of this central portion, thereby forming a bipolar magnet with radially polarized magnetized teeth that respectively define a first magnetic tooth system. This allows the magnetic field lines between adjacent bipolar magnets to be effectively closed through the central portion of the first wheel.

[0021] In an advantageous alternative embodiment, the second and third magnetic gear systems have different pitches. It should be noted that the pitch of the gear system is defined as the length of the arc between two adjacent teeth of the gear system on a circle tangent to the toothed wheel meshing with it. This effectively compensates for rotational offset between the second and third wheels, thereby improving the efficiency of the magnetic gears. Preferably, preferred torque transmission between these wheels is achieved by optimally spacing the teeth of the second and third wheels. When the second and third wheels have the same diameter, the second wheel can therefore include N2 teeth and the third wheel can include N3 teeth, wherein the number of teeth N3 of the third wheel is greater than the number of teeth N2 of the second wheel.

[0022] In a specific alternative embodiment, the mechanism also includes a check valve mechanically coupled to the third wheel. This prevents the wheel from slipping backward, which can occur, in particular, with high restoring torque, such as, for example, when the mainspring is wound. Such slippage can lead to a runaway effect detrimental to the mechanism, causing the third wheel to rotate freely in the direction opposite to the desired torque transmission direction. For example, such a runaway effect can be triggered by vibration, shock, or any other mechanical disturbance within the mechanism involved (e.g., winding the mainspring).

[0023] Advantageously, the third wheel includes a rim forming a continuous circular base for the third magnetic gear system, the rim being made of a soft ferromagnetic material so as to form a closed magnetic circuit for generating a second magnetic flux that generates magnetic coupling between the second and third wheels.

[0024] According to an advantageous embodiment of the invention, the magnetic gear further includes a fourth wheel with permanent magnet poles arranged to form magnetized teeth of a fourth magnetic gear system, from which a third magnetic flux of alternating polarity emerges. In this advantageous embodiment, similar to the second gear system, the third magnetic gear system is arranged on a rim made of a non-magnetic material, with non-magnetic regions between the teeth of the third gear system. The fourth wheel is then configured such that, when projected onto a second plane, it lies within a circle circumscribed about the third wheel, which extends in the second plane and the second plane is perpendicular to the axis of rotation of the third wheel. The second and third magnetic gear systems each have a greater number of teeth than the fourth magnetic gear system. The third magnetic gear system also has a third magnetic coupling with the fourth magnetic gear system, such that when one of the third and fourth wheels is driven to rotate, the other wheel is also driven to rotate, wherein a third transmission ratio is defined by the third and fourth magnetic gear systems. This third magnetic coupling is generated, for the most part, by a magnetic flux from the third magnetic flux, which temporarily polarizes the teeth of the third magnetic gear system in the form of magnetic attraction, such that these teeth are located in the magnetic coupling region with the gear system and thus the third magnetic flux passes through these teeth respectively. The fourth wheel is arranged such that the magnetic coupling region with the first wheel and the magnetic coupling region with the fourth wheel are at least largely superimposed, and such that the second and third magnetic fluxes thus pass through the teeth of the third gear system located in the common magnetic coupling region of the first and fourth wheels, the second and third magnetic fluxes having the same polarity in each of these teeth. Finally, the second magnetic coupling between the second and third magnetic gear systems is also partially generated by a fourth magnetic flux, which emerges from the teeth of the third magnetic gear system that are temporarily magnetized by the fourth magnetic gear system, and which also temporarily polarizes the teeth of the second magnetic gear system in the form of magnetic attraction, respectively, the teeth of which are temporarily located in the magnetic coupling region with the fourth wheel.

[0025] This advantageous embodiment improves the magnetic coupling efficiency between the second and third gears. The magnetic gears are therefore symmetrical.

[0026] Preferably, the fourth gear includes at least four magnetized teeth. The fourth magnetic tooth system includes N4 teeth, and the third magnetic tooth system includes N3 teeth. Advantageously, the number N4 is an even number between four and ten (including endpoint values); and the ratio between the number N3 and the number N4 is greater than or equal to two, preferably greater than or equal to three.

[0027] According to the first alternative embodiment, the fourth wheel is substantially disposed in the second plane, within the third wheel; the third wheel has an uninterrupted annular shape in the second plane, and the magnetized teeth of the fourth magnetic tooth system are arranged such that a third magnetic flux emerges from these magnetized teeth in the principal radial direction relative to the axis of rotation of the fourth wheel.

[0028] According to the second alternative embodiment, the fourth wheel is disposed outside the second plane, wherein the axis of rotation of the fourth wheel is arranged perpendicular to the second plane, and the magnetized teeth of the fourth tooth system are arranged such that the third magnetic flux emerges from these magnetized teeth in a principal direction that is inclined or parallel to the axis of rotation of the fourth wheel (axial polarization).

[0029] As with the first wheel, in the case where the fourth wheel includes multiple bipolar magnets with radial polarization, advantageously, the fourth wheel has a central portion made of ferromagnetic material, and the permanent magnet poles of the fourth wheel are arranged in pairs with an equal number of complementary magnet poles around the periphery of the central portion, thereby forming multiple bipolar magnets defining the magnetized teeth of the fourth magnetic tooth system. Preferably, the fourth wheel is mounted such that it can rotate freely.

[0030] According to an exemplary embodiment of the present invention, the second and third rounds are coplanar.

[0031] According to another exemplary embodiment of the invention, the second and third wheels extend in separate planes. According to a first alternative embodiment, these separate planes are not parallel. According to another alternative embodiment, these separate planes are parallel, and advantageously, the second and third magnetic tooth systems at least partially overlap each other in the magnetic coupling region with the first magnetic tooth system. Attached Figure Description

[0032] The objectives, advantages, and features of the mechanism according to the invention will become more apparent in the following description of various non-limiting embodiments illustrated by way of the accompanying drawings, wherein:

[0033] - Figure 1 This is a top view of a mechanism incorporating magnetic gears according to a specific alternative embodiment of the present invention;

[0034] - Figure 2 It is similar to Figure 1 A top view of a first example of a first preferred embodiment of a mechanism according to the present invention;

[0035] - Figure 3 It is similar to Figure 2 A view of a second example of a mechanism according to a first embodiment of the present invention;

[0036] - Figure 4 It is similar to Figure 2 A view of a first example of a second advantageous embodiment of the mechanism according to the invention;

[0037] - Figure 5 It is similar to Figure 4 A view of a second example of a mechanism according to the invention;

[0038] - Figure 6 It is similar to Figure 3 The view in the figure is a third example of a first embodiment of the mechanism according to the invention, wherein the mechanism of the invention includes a check device for a wheel mechanically coupled to a magnetic gear; and

[0039] - Figure 7 This is a perspective view of an example of a third specific embodiment of the mechanism of the present invention. Detailed Implementation

[0040] Figure 1 A specific alternative embodiment of the mechanism 1 (particularly of a timepiece type) according to the invention is shown, which includes a magnetic gear 2 as the subject of the invention. The invention originates from the general inventive concept of providing two wheels 6B, 6C in the magnetic gear 2, each wheel having teeth made of a soft ferromagnetic material, preferably having a relatively high permeability, wherein at least one of the two wheels 6B, 6C is magnetically coupled to the other wheel, which has a smaller diameter and, in particular, a pinion-like size, and which has permanent magnet poles 7 arranged circularly about its axis of rotation. Figure 1 In this case, the other wheel is formed by a single rotating element 5 with permanent magnetization. This rotating element 5 is a rotating bipolar magnet 5 in the form of a disk, having a central axis of rotation perpendicular to the magnetic axis of the bipolar magnet. The rotating bipolar magnet 5 generates a magnetic field that couples with two corresponding portions of wheels 6B and 6C located in the magnetic coupling region between the two wheels 6B and 6C. This magnetic coupling region corresponds to the magnetic meshing region of the two wheels 6B and 6C.

[0041] The magnetic field generated by the rotating bipolar magnet 5 produces local and temporary magnetization on each of the two wheels 6B, 6C. More specifically, this magnetization occurs in the teeth of these wheels 6B, 6C made of soft ferromagnetic material, which are active at a given moment, i.e., when they are temporarily in the magnetic engagement region, which, by definition, corresponds to the magnetic coupling region provided between the two wheels 6B, 6C. The number of permanent magnet poles of the wheel (illustrated by the rotating element 5) required to generate such local magnetization is thus significantly reduced to at least two poles forming the bipolar magnet. The two wheels 6B, 6C are arranged such that the teeth of wheel 6B and the teeth of wheel 6C have direct magnetic coupling to each other in the magnetic engagement region, partially and continuously in adjacent sets of teeth. This direct magnetic coupling is induced by the permanent magnet poles 7 of the smaller wheel 5 via the teeth of wheel 6B magnetized by these permanent magnet poles 7. Therefore, when one of the two wheels 6B and 6C, or the smaller wheel 5, is driven to rotate, the other two wheels are also driven to rotate as a result of magnetic coupling in the form of attraction between the teeth of the three wheels 5, 6B, and 6C within the magnetic meshing region provided for them. To avoid rotation along the magnetic field lines ( Figure 1 To prevent magnetic field leakage (not shown), the distance between two adjacent teeth of wheel 6B is advantageously designed to be greater than twice the shortest distance between the corresponding teeth of the two wheels 6B and 6C. Therefore, the magnetic field lines 11 generated by the magnetic coupling between the three wheels 5, 6B, and 6C are locally confined to the vicinity of the location where torque transmission occurs between wheels 6B and 6C.

[0042] In the following description, elements indicated by the same reference numerals are similar. Without limiting the scope of the invention, mechanism 1 is preferably a timekeeping mechanism.

[0043] like Figures 2 to 7 As shown, the magnetic gear 2 includes at least three wheels 6A, 6B, and 6C. Generally speaking, the first wheel 6A, with a diameter smaller than the other two wheels 6B and 6C, has N1 permanent magnet poles 7 arranged in a circle and defining a first magnetic tooth system 8. The N1 permanent magnet poles 7 form the magnetized teeth of the first magnetic tooth system 8, from which a first magnetic flux with alternating polarities emerges. Because the magnetic poles 7 are arranged in a circle with alternating polarization, there is an even number of magnetic poles. Preferably, the number N1 is an even number between four and ten (including endpoint values). Figures 2 to 6 In the first round 6A, the outer magnetic pole 7 is associated with the same number of inner magnetic poles, thus forming a bipolar magnet with radial polarization, which respectively defines the magnetized teeth of the first magnetic tooth system 8.

[0044] The second wheel 6B has N2 teeth made of a soft ferromagnetic material that define a second magnetic gear system 10. The second magnetic gear system 10 is arranged on a rim 14 made of a non-magnetic material, and there are non-magnetic regions between the teeth of the second magnetic gear system 10. The number of teeth N2 of the second wheel 6B is greater than the number of magnetic poles 7 N1 of the first wheel 6A. The ratio between the number of teeth N2 of the second wheel 6B and the number of magnetic poles 7 N1 of the first wheel 6A is advantageously greater than or equal to two, preferably greater than or equal to three. The second magnetic gear system 10 has a first direct magnetic coupling with the first magnetic gear system 8, such that when one of the first wheel 6A and the second wheel 6B is driven to rotate, the other wheel 6A, 6B is also driven to rotate through the first direct magnetic coupling between the first gear system 8 and the second gear system 10, wherein the transmission ratio is defined by the first gear system 8 and the second gear system 10. The first direct magnetic coupling (at least for most of its purpose) is generated by a magnetic flux from a first magnetic flux arising from the first tooth system 8, which temporarily polarizes the teeth of the second magnetic tooth system 10 in the form of magnetic attraction as follows: these teeth are temporarily located in the magnetic coupling region with the first magnetic tooth system and thus the first magnetic flux passes through these teeth respectively.

[0045] The third wheel 6C has N3 teeth made of soft ferromagnetic material that define the third magnetic tooth system 12. Without limiting the scope of the invention, the second wheel 6B and the third wheel 6C have the same diameter. The number of teeth N3 in the third wheel 6C is greater than the number of magnetic poles 7 N1 in the first wheel 6A. The ratio between the number of teeth N3 in the third wheel 6C and the number of magnetic poles 7 N1 in the first wheel 6A is advantageously greater than or equal to two, preferably greater than or equal to three. The third wheel 6C is arranged relative to the second wheel 6B in such a way that the third magnetic tooth system 12 has a second direct magnetic coupling in the continuation of the magnetic coupling region between the first tooth system 8 and the second tooth system 10, by means of the temporarily magnetized teeth of the second tooth system 10. In this way, when one of the second wheel 6B and the third wheel 6C is driven to rotate, the other wheel 6B or 6C is also driven to rotate by the second direct magnetic coupling between the second tooth system 10 and the third tooth system 12, wherein the transmission ratio is defined by the second tooth system 10 and the third tooth system 12. The second direct magnetic coupling (at least in part) is generated by a second magnetic flux that emerges from the temporarily magnetized teeth of the second magnetic tooth system 10, which have alternating polarities; these teeth themselves have been temporarily magnetized by the permanent magnet poles 7 of the first wheel 6A via the first direct magnetic coupling. The second magnetic flux thus temporarily polarizes the teeth of the third magnetic tooth system 12 in the form of magnetic attraction, as follows: these teeth are temporarily located in the magnetic coupling region between the first, second, and third wheels, and the second magnetic flux passes through these teeth respectively.

[0046] The teeth of the second round 6B and the third round 6C are made of a soft ferromagnetic material, which preferably has high magnetic permeability, for example, such as Mu alloy (Mu-metal).

[0047] Preferably and as Figures 2 to 7 As shown, the first wheel 6A is positioned within a circle circumscribed around the second wheel 6B when projected onto a first plane P1, the second wheel 6B extending within the first plane P1 and the first plane P1 being perpendicular to the axis of rotation of the second wheel 6B. The second wheel 6B and the third wheel 6C may extend in the same overall plane, or in separate planes that may be parallel or non-parallel to each other. When the second wheel 6B and the third wheel 6C extend in separate planes that are substantially parallel to each other, the second magnetic tooth system 10 and the third magnetic tooth system 12 are preferably at least partially superimposed in the magnetic coupling region with the first magnetic tooth system 10. The first wheel 6A, the second wheel 6B, and the third wheel 6C are arranged such that their magnetic tooth systems 8, 10, and 12 do not contact each other.

[0048] The following will refer to Figure 2 , 3 Sections 6 and 7 describe a first preferred embodiment of the mechanism 1 according to the invention, comprising a magnetic gear 2. According to this preferred embodiment of the mechanism 1, the magnetic gear 2 comprises three wheels 6A, 6B, and 6C. Magnetized teeth 7 of a first gear train 8 are arranged such that a first magnetic flux emerges from these magnetized teeth 7 in the principal radial direction relative to the axis of rotation of the first wheel 6A, and the bipolar magnets defining the magnetized teeth thus have radial polarization / magnetization. The first and second magnetic couplings are generated entirely by the first magnetic flux emerging from the outer permanent magnet poles 7 of the first wheel 6A. The permanent magnet poles 7 are typically arranged in pairs with the same number of complementary magnetic poles, arranged around a central portion 9 forming the axis of the first wheel 6A, or arranged in an opening through which such an axis passes, the central portion 9 being advantageously made of a ferromagnetic material or a Mu alloy material. Preferably, as Figure 2 , 3 As shown in Figure 6, the first wheel 6A is mounted so that it can rotate freely on its axis.

[0049] exist Figure 2In a first example of a first preferred embodiment of the mechanism 1 shown, a first wheel 6A is substantially disposed in a first plane P1, within a second wheel 6B. The second wheel 6B thus forms a shield for the first wheel 6A. The second wheel 6B has an annular shape that does not intersect in the first plane P1. The first wheel 6A includes six bipolar magnets with radial magnetization, which respectively form magnetized teeth of a first magnetic tooth system 8. The second wheel 6B includes eighteen teeth made of a soft ferromagnetic material forming a second magnetic tooth system 10. The third wheel 6C includes an annular rim made of a non-magnetic material (typically a soft ferromagnetic material), at the outer periphery of which defines twenty-four teeth made of a soft ferromagnetic material forming a third magnetic tooth system 12. This annular rim forms a continuous circular base for the third magnetic tooth system 12. This alternative embodiment effectively compensates for the rotational offset between the second wheel 6B and the third wheel 6C, thereby improving the efficiency of the magnetic gear 2, because the number of teeth N3 of the third wheel 6C is greater than the number of teeth N2 of the second wheel 6B. More generally, in this first example of the first preferred embodiment, the second magnetic gear train 10 and the third magnetic gear train 12 have different tooth pitches. The pitch of the gear trains 10, 12 is defined as the length of the arc between two adjacent teeth of the gear trains 10, 12 on a circle tangent to the toothed wheels meshing with the gear trains 10, 12. Preferably, optimized torque transmission is achieved between the wheels 6B, 6C by optimally spacing the teeth of the second wheel 6B and the third wheel 6C.

[0050] according to Figure 3 In a second example of the first preferred embodiment of the mechanism 1 shown, the first wheel 6A includes a bipolar magnet with radial magnetization, which respectively forms six magnetized teeth of the first magnetic tooth system 8. The second wheel 6B includes eighteen teeth made of soft ferromagnetic material forming the second magnetic tooth system 10. The third wheel 6C includes an annular rim made of non-magnetic material (typically soft ferromagnetic material), and eighteen teeth made of soft ferromagnetic material are also defined at the outer periphery of the rim to form the third magnetic tooth system 12.

[0051] according to Figure 6 A third example of the first preferred embodiment of the mechanism 1 shown indicates that the mechanism 1 further includes a check device 20 mechanically coupled to the third wheel 6C. According to... Figure 6 In the specific embodiment shown, the check valve 20 typically includes a ratchet 22 and a pawl 24. The ratchet 22 is fixed to the third wheel 6C for rotation therewith, and the ratchet 22 has teeth extending radially relative to the axis of rotation of the wheel 22. The pawl 24 engages with the teeth of the ratchet 22 in such a way as to prevent the third wheel 6C from rotating in a direction opposite to the direction corresponding to the desired torque transmission, in this case... Figure 6In the exemplary embodiment, this is indicated by arrow F1. This prevents the third wheel 6C from rotating freely in the direction of arrow F1 in the event of vibration, shock, or any other mechanical disturbance within the timekeeping mechanism (e.g., winding of the mainspring), which could impair its mechanical integrity. Although the presence of this feature has been illustrated with reference to the first preferred embodiment of mechanism 1, other embodiments of mechanism 1 according to the invention are also conceivable.

[0052] The following will refer to Figure 4 and 5 A second advantageous embodiment of the mechanism 1 including the magnetic gear 2 according to the present invention is described. According to this second embodiment of the mechanism 1, the magnetic gear 2 further includes a fourth gear 6D in addition to the three gears 6A, 6B, and 6C. The fourth gear 6D is smaller in diameter than the second gear 6B and the third gear 6C, and it is provided with N4 external permanent magnet poles 15 arranged in a circle, and these permanent magnet poles 15 define a fourth magnetic tooth system 16. The N4 permanent magnet poles 15 form the magnetized teeth of the fourth magnetic tooth system 16, from which a third magnetic flux with alternating polarities emerges. Since the magnetic poles 15 are arranged in a circle with alternating polarization, there is an even number of magnetic poles. Preferably, like the first gear 6A, the number N4 is an even number between four and ten (including endpoint values). In particular, the first and fourth gears are identical or similar, where N1 = N4.

[0053] The outer magnetic poles 15 are typically arranged in pairs with the same number of inner magnetic poles (complementary magnetic poles), thereby forming a plurality of bipolar magnets with radial polarization, and their arrangement around a central portion 17 forming the axis of the fourth wheel 6D or in an opening through which the axis passes. The central portion 17 is advantageously made of ferromagnetic material or Mu alloy material. The number of teeth N2 of the second wheel 6B and the number of teeth N3 of the third wheel 6C are greater than the number of magnetic poles 15 N4 of the fourth wheel 6D. In the second embodiment, similar to the second tooth system, a third magnetic tooth system 12 is arranged on a rim 14 made of a non-magnetic material, wherein there are non-magnetic regions between the teeth of the third tooth system. The magnetized teeth 15 of the fourth tooth system 16 are arranged such that a third magnetic flux emerges from these magnetized teeth in the principal radial direction relative to the axis of rotation of the fourth wheel 6D, thus giving the bipolar magnets radial polarization / magnetization. The third magnetic coupling between the fourth wheel and the third wheel (for the most part) is generated by the third magnetic flux emerging from the magnetized teeth 15.

[0054] The third magnetic gear system 12 has a third magnetic coupling with the fourth magnetic gear system 16, such that when one of the third wheel 6C and the fourth wheel 6D is driven to rotate, the other wheel 6C or 6D is also driven to rotate via the third magnetic coupling, wherein the transmission ratio is defined by the third and fourth magnetic gear systems. This third magnetic coupling (for the most part) is generated by the magnetic flux from the third magnetic flux generated by the fourth magnetic gear system 16, which temporarily polarizes the teeth of the third magnetic gear system 12 in the form of magnetic attraction, such that these teeth are temporarily located in the magnetic coupling region with the fourth magnetic gear system 16 and therefore the third magnetic flux passes through these teeth respectively. Figure 4 and Figure 5 As shown, the fourth wheel 6D is arranged such that the magnetic coupling region with the first wheel 6A and the magnetic coupling region with the fourth wheel 6D are at least substantially superimposed, and such that the second and third magnetic fluxes thus pass through the same teeth of the third tooth system 12 located in the common magnetic coupling region of the first wheel 6A and the fourth wheel 6D, the second and third magnetic fluxes having the same polarity in each of these teeth. The second magnetic coupling between the second magnetic tooth system 10 and the third magnetic tooth system 12 is therefore also partially generated by the fourth magnetic flux arising from the teeth of the third magnetic tooth system 12, which are temporarily magnetized by the third magnetic flux arising from the fourth magnetic tooth system 16. More specifically, due to the symmetry of the system, the second magnetic coupling is generated by the second magnetic flux (generated by the first magnetic flux provided by the first permanent magnet tooth system) and the fourth magnetic flux (generated by the third magnetic flux provided by the fourth permanent magnet tooth system) in substantially equal portions. The fourth magnetic flux also partially and temporarily polarizes the teeth of the second magnetic tooth system 10, which are temporarily located in the magnetic coupling region with the fourth wheel 6D, in the form of magnetic attraction.

[0055] Preferably, the fourth wheel 6D is positioned within the circle circumscribed around the third wheel 6C when projected onto the second plane, the third wheel 6C extending within the second plane and the second plane being perpendicular to the axis of rotation of the third wheel 6C. Preferably, the fourth wheel 6D is mounted so that it can rotate freely on its axis. Even more preferably, the first wheel 6A and the fourth wheel 6D have the same diameter.

[0056] exist Figure 4In a first example of the second embodiment of the mechanism 1 shown, the fourth wheel 6D is substantially disposed within a second plane in which the third wheel 6C extends. The third wheel 6C thus forms a shield for the fourth wheel 6D. According to this exemplary embodiment, the third wheel 6C has an annular shape that does not intersect in the second plane. Each of the first wheel 6A and the fourth wheel 6D includes six bipolar magnets with radial magnetization. The six bipolar magnets of the first wheel 6A and the fourth wheel 6D respectively form a first magnetic tooth system 8 and a fourth magnetic tooth system 16. The first wheel 6A and the fourth wheel 6D are advantageously mounted such that they can rotate freely on their respective axes. The magnetized teeth 15 of the fourth tooth system 16 are arranged such that a third magnetic flux emerges from these magnetized teeth 15 in the principal direction of the radial direction relative to the axis of rotation of the fourth wheel 6D, and the bipolar magnets thus have radial polarization or magnetization. Each of the second wheel 6B and the third wheel 6C includes eighteen teeth made of a soft ferromagnetic material.

[0057] Figure 5 The second example of the second embodiment of the mechanism 1 shown differs from the first example in that the first wheel 6A and the fourth wheel 6D are mechanically connected to the respective second wheel 6B and third wheel 6C via corresponding mechanical gears 18 of the mechanism 1. Although this feature has been illustrated with reference to the second embodiment of the mechanism 1, other embodiments of the mechanism 1 according to the invention are conceivable. It should be noted that the corresponding numbers of teeth in the second and third magnetic gear systems may be different, and as in the first embodiment, the tooth pitch of the second magnetic gear system and the tooth pitch of the third magnetic gear system may advantageously be different.

[0058] According to another example of the second embodiment of mechanism 1 (not shown in the figures), the fourth wheel 6D is disposed outside the second plane, wherein the axis of rotation of the fourth wheel 6D is arranged perpendicular to the second plane. The third wheel 6C and the fourth wheel 6D thus extend in different planes parallel to each other. The magnetized teeth 15 of the fourth tooth system 16 are thus arranged such that the third magnetic flux emerges from these magnetized teeth 15 in a principal direction that is inclined or parallel to the axis of rotation of the fourth wheel 6D. The fourth wheel 6D may generally be arranged above or below the third wheel 6C such that its respective two tooth systems 12, 16 have circumcircles with tangent points (tangent to each other, and one inside the other) when projected onto the plane, or optionally have slight recesses.

[0059] According to another example of the second embodiment of mechanism 1 (not shown in the figures), the fourth wheel 6D is disposed outside the second plane, wherein the axis of rotation of the fourth wheel 6D is arranged in an inclined manner relative to the second plane. The magnetized teeth 15 of the fourth tooth system 16 are thus arranged such that the third magnetic flux emerges from these magnetized teeth 15 in the principal direction of the radial direction relative to the axis of rotation of the fourth wheel 6D.

[0060] The following will refer to Figure 7 A third embodiment of the mechanism 1 including the magnetic gear 2 according to the present invention is described. According to this third embodiment of the mechanism 1, the magnetic gear 2 includes three wheels 6A, 6B, and 6C. A first wheel 6A is disposed outside a first plane P1 in which a second wheel 6B extends, wherein the axis of rotation of the first wheel 6A is arranged perpendicular to the first plane P1. The first wheel 6A and the second wheel 6B thus extend in different planes parallel to each other. The magnetized teeth 7 of a first tooth train 8 are arranged such that a first magnetic flux emerges from these magnetized teeth 7 in the direction of the principal axis (i.e., parallel to the axis of rotation of the first wheel 6A), and the bipolar magnets 7 thus have axial polarization or magnetization. More specifically, the first wheel 6A is disposed above the second wheel 6B such that its corresponding two tooth trains 8, 10 are partially overlapped, and the bipolar magnets 7 temporarily generating first and second magnetic couplings are overlapped on the second tooth train and located at a relatively small distance from the second tooth train. The first and second magnetic couplings are generated entirely by the first magnetic flux emerging from the outer permanent magnet poles 7 of the first wheel 6A. Figure 7 The diagram shows a line 11 of a magnetic field generated by two adjacent magnets of the first wheel and substantially creating magnetic coupling between the three wheels 6A, 6B, and 6C. Preferably, the first wheel 6A is mounted such that it can rotate freely.

[0061] Below the upper disc-shaped member 26 mounted on the first wheel 6A, the lower magnetic poles 7 are typically arranged in pairs with the same number of upper magnetic poles (complementary magnetic poles). The upper disc-shaped member 26 is advantageously made of ferromagnetic material or Mu alloy material. The upper disc-shaped member 26 of the first wheel 6A thus allows the magnetic flux of the magnet to be closed on the side opposite to the second magnetic tooth system.

[0062] There are various possibilities for arranging the first wheel 6A and the second wheel 6B in different parallel planes. For example, a first possibility involves using a plate with a circular recess therein. This plate thus defines two layers: an upper layer on which one of the two wheels 6A, 6B (preferably the second wheel 6B) can be disposed; and a lower layer at the bottom of the recess on which the other wheel 6A, 6B (preferably the first wheel 6A) can be disposed. Alternatively, the bottom of the recess may include means for holding the first wheel 6A within the recess. In the latter case, the second wheel 6B may have a cross in plane P1 connected to a mandrel. Another possibility is to use a date ring type ring, which is placed in a groove and driven by the groove to rotate.

[0063] According to another embodiment of mechanism 1 (not shown in the figures), the magnetic gear 2 includes three wheels 6A, 6B, and 6C. The first wheel 6A is disposed outside a first plane P1, wherein the axis of rotation of the first wheel 6A is arranged perpendicular to the first plane P1. The first wheel 6A and the second wheel 6B thus extend in different planes parallel to each other. The magnetized teeth 7 of the first tooth system 8 are arranged such that a first magnetic flux emerges from these magnetized teeth 7 in a principal direction inclined relative to the axis of rotation of the first wheel 6A. In the latter case, the first wheel 6A is thus disposed slightly behind the second tooth system of the second wheel 6B, for example, in such a way that its respective two tooth systems 8, 10, when projected onto plane P1, respectively have a circumscribed circle and an inscribed circle that is substantially tangent at one point.

[0064] According to another embodiment of mechanism 1 (not shown in the figures), the magnetic gear 2 includes three wheels 6A, 6B, and 6C. The first wheel 6A is disposed outside a first plane P1, wherein the axis of rotation of the first wheel 6A is arranged obliquely relative to the first plane P1. The first wheel 6A and the second wheel 6B thus extend in different planes and form an angle between them. The magnetized teeth 7 of the first wheel 6A are therefore advantageously arranged such that a first magnetic flux emerges from these magnetized teeth 7 in the principal direction of the radial direction relative to the axis of rotation of the first wheel 6A. The first and second magnetic couplings are generated entirely by the first magnetic flux emerging from the outer permanent magnet poles 7 of the first wheel 6A.

[0065] A general alternative embodiment is provided for one of the second and third wheels, which is driven by a drive mechanism to rotate and thus drive in a magnetic gear, and the other of the two wheels is driven to perform the function of the mechanism or to transmit torque in the mechanism. The first and fourth wheels (where applicable) are mounted such that they are freely rotatable or such that they are mechanically connected to the second and third wheels respectively.

Claims

1. A mechanism (1) including a magnetic gear (2), the magnetic gear (2) comprising a first wheel (6A) and a second wheel (6B), the first wheel (6A) being provided with permanent magnet poles (7), the permanent magnet poles (7) being arranged as magnetized teeth forming a first magnetic tooth system (8), and a first magnetic flux having alternating polarities emerging from the magnetized teeth respectively; characterized in that, The second wheel has teeth made of soft ferromagnetic material that define a second magnetic gear system (10). The number of teeth in the second magnetic gear system (10) is greater than the number of teeth in the first magnetic gear system (8), and it has a first magnetic coupling with the first magnetic gear system (8), such that when one of the first wheel and the second wheel (6A, 6B) is driven to rotate, the other wheel is also driven to rotate. A first transmission ratio is defined by the first magnetic gear system and the second magnetic gear system, and the first magnetic coupling at least partially... The magnetic flux is generated from the first magnetic flux, which temporarily polarizes the teeth of the second magnetic gear system (10) in the form of magnetic attraction. These teeth are temporarily located in the magnetic coupling region with the first magnetic gear system (8), and therefore the magnetic flux passes through these teeth respectively. The magnetic gear (2) also includes a third wheel (6C) with teeth made of soft ferromagnetic material that define the third magnetic gear system (12), the number of which is greater than that of the first magnetic gear system (8). The number of, the second magnetic gear system (10) is arranged on a rim made of non-magnetic material, wherein there is a non-magnetic region between the teeth of the second magnetic gear system, the third wheel (6C) is arranged relative to the second wheel (6B) such that the third magnetic gear system (12) and the temporarily magnetized teeth of the second magnetic gear system (10) have a second magnetic coupling in the magnetic coupling region, such that when one of the second wheel and the third wheel (6B, 6C) is driven to rotate, the other wheel is also driven to rotate, wherein the second gear system and the third magnetic gear system define a second transmission ratio, through which the second magnetic coupling is generated at least in part by a second magnetic flux, the second magnetic flux respectively emerging from the temporarily magnetized teeth of the second magnetic gear system (10) having alternating polarities, the second magnetic flux temporarily polarizing the teeth of the third magnetic gear system (12) in the form of magnetic attraction: these teeth are temporarily located in the magnetic coupling region, and thus the second magnetic flux passes through these teeth respectively, the magnetic coupling region being the magnetic meshing region defined by the first wheel, the second wheel and the third wheel.

2. The mechanism (1) according to claim 1, characterized in that, The first magnetic tooth system (8) includes N1 teeth, the second magnetic tooth system (10) includes N2 teeth, and the third magnetic tooth system (12) includes N3 teeth; wherein the quantity N1 is an even number between four and ten, including endpoint values; and wherein the ratio between the quantity N2 and the quantity N1 and the ratio between the quantity N3 and the quantity N1 are each greater than or equal to two.

3. The mechanism (1) according to claim 2, characterized in that, The ratio between quantity N2 and quantity N1, and the ratio between quantity N3 and quantity N1, are both greater than or equal to three.

4. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The first wheel (6A) is also mechanically connected to the second wheel (6B).

5. The mechanism (1) according to claim 4, characterized in that, The first wheel (6A) is mechanically connected to the second wheel (6B) via a gear train (18).

6. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The first wheel (6A) is installed so that the first wheel (6A) can rotate freely.

7. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The first wheel (6A) is configured such that when projected onto the first plane (P1), the first wheel (6A) is inside a circle circumscribed around the second wheel (6B), the second wheel (6B) extends in the first plane (P1), and the first plane (P1) is perpendicular to the axis of rotation of the second wheel (6B).

8. The mechanism (1) according to claim 7, characterized in that, The first wheel (6A) is disposed in the first plane (P1) and within the second wheel (6B); the second wheel (6B) has an annular shape without intersection in the first plane (P1), and the magnetized teeth of the first magnetic tooth system (8) are arranged such that the first magnetic flux emerges from the magnetized teeth in the principal radial direction relative to the axis of rotation of the first wheel (6A).

9. The mechanism (1) according to claim 7, characterized in that, The first wheel (6A) is disposed outside the first plane (P1), wherein the axis of rotation of the first wheel (6A) is arranged perpendicular to the first plane (P1), and the magnetized teeth of the first magnetic tooth system (8) are arranged such that the first magnetic flux emerges from the magnetized teeth in a main direction that is inclined or parallel to the axis of rotation of the first wheel (6A).

10. The mechanism (1) according to claim 7, characterized in that, The first wheel (6A) is disposed outside the first plane (P1), wherein the axis of rotation of the first wheel (6A) is disposed at an inclination relative to the first plane (P1), and the magnetized teeth of the first magnetic tooth system (8) are arranged such that the first magnetic flux emerges from the magnetized teeth in the main radial direction relative to the axis of rotation of the first wheel (6A).

11. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The first wheel has a central portion (9) made of ferromagnetic material, and the permanent magnet poles (7) of the first wheel are arranged in pairs with the same number of complementary magnet poles on the periphery of the central portion (9) to form bipolar magnets that define the magnetized teeth of the first magnetic tooth system.

12. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The second and third magnetic tooth systems (10, 12) have different pitches, the pitch of which is defined as the length of the arc between two adjacent teeth of the magnetic tooth system on a circle tangent to the toothed wheel, the toothed wheel meshing with the magnetic tooth system.

13. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The mechanism (1) also includes a check device (20) mechanically connected to the third wheel (6C).

14. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The third wheel (6C) includes a rim forming a continuous circular base for the third magnetic gear system (12), the rim being made of a soft ferromagnetic material to form a closed magnetic circuit for the second magnetic flux.

15. The mechanism (1) according to claim 7, characterized in that, The magnetic gear (2) further includes a fourth wheel (6D) with permanent magnet poles (15), the permanent magnet poles (15) being arranged to form magnetized teeth of a fourth magnetic tooth system (16), and a third magnetic flux with alternating polarities emerging from the magnetized teeth of the fourth magnetic tooth system (16); the third magnetic tooth system (12) is arranged on a rim made of non-magnetic material, and there are non-magnetic regions between the teeth of the third magnetic tooth system (12); the fourth wheel (6D) is configured such that when projected onto a second plane, the fourth wheel (6D) is within a circle circumscribed around the third wheel (6C), and the third wheel (6C) is within the circle circumscribed around the second plane. Extending in a second plane and perpendicular to the axis of rotation of the third wheel (6C); each of the second and third magnetic gear systems (10, 12) has a greater number of teeth than the fourth magnetic gear system (16) and also has a third magnetic coupling with the fourth magnetic gear system (16), such that when one of the third and fourth wheels (6C, 6D) is driven to rotate, the other wheel is also driven to rotate, wherein a third transmission ratio is defined by the third and fourth magnetic gear systems (12, 16), through which the third magnetic coupling is, for the most part, derived from Generated from the magnetic flux in the third magnetic flux, the third magnetic flux temporarily polarizes the teeth of the third magnetic tooth system (12) in the form of magnetic attraction as follows: these teeth are temporarily located in the magnetic coupling region with the fourth magnetic tooth system (16), and thus the third magnetic flux passes through these teeth respectively; the fourth wheel (6D) is arranged such that the magnetic coupling region with the first wheel (6A) and the magnetic coupling region with the fourth wheel (6D) are at least largely superimposed, and such that the second and third magnetic fluxes thus pass through the common area between the first wheel and the fourth wheel (6A, 6D). The teeth of the third magnetic tooth system (12) in the magnetic coupling region, wherein the second magnetic flux and the third magnetic flux have the same polarity in each of these teeth; the second magnetic coupling between the second magnetic tooth system and the third magnetic tooth system (10, 12) is also partially generated by a fourth magnetic flux, which appears from the teeth of the third magnetic tooth system (12) temporarily magnetized by the fourth magnetic tooth system (16), and the fourth magnetic flux also temporarily polarizes the teeth of the second magnetic tooth system (10) in the form of magnetic attraction, wherein these teeth are temporarily located in the magnetic coupling region with the fourth wheel (6D).

16. The mechanism (1) according to claim 15, characterized in that, The fourth wheel (6D) has a central portion (17) made of ferromagnetic material, and the permanent magnet poles (15) of the fourth wheel (6D) are arranged in pairs with the same number of complementary magnet poles on the periphery of the central portion (17) to form a bipolar magnet defining the magnetized teeth of the fourth magnetic tooth system; and wherein the fourth wheel is mounted such that the fourth wheel can rotate freely.

17. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The second and third rounds (6B, 6C) are coplanar.

18. The mechanism (1) according to any one of claims 1 to 3, characterized in that, The second and third wheels extend in separate planes.

19. The mechanism (1) according to claim 18, characterized in that, The separated planes are not parallel.

20. The mechanism (1) according to claim 18, characterized in that, The separated planes are parallel, and the second and third magnetic tooth systems (10, 12) are at least partially superimposed in the magnetic coupling region with the first magnetic tooth system (8).

21. The mechanism (1) according to claim 1, characterized in that, The mechanism (1) is a timekeeping mechanism.

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