HK1245909B - Magnetic antishock system for a timepiece arbor - Google Patents

Description

Magnetic anti-shock system for watch arbors

Technical Field

The present invention relates to a timepiece subassembly for a watch, comprising a main structure and a spindle, said spindle being pivotally movable about a pivot axis inside at least one housing of said main structure, said spindle comprising at least one surface made of a magnetized or ferromagnetic material or an electrically charged or electrostatically conductive material, and said main structure comprising at least one pole shoe, said at least one pole shoe being arranged to generate a magnetic or electrostatic field close to at least one of said surfaces in order to hold said spindle axially and radially.

The invention also relates to a movement comprising at least one such subassembly.

The invention also relates to a watch comprising at least one such subassembly.

The present invention relates to the field of watch movements comprising pivoting mechanical components.

Background Art

In watchmaking, and more specifically in watchmaking, mechanical techniques are often used to hold components, particularly spindles, in a specific position. This can be achieved by elastic systems against stops, particularly when a certain degree of movement is required in the event of vibrations. For example, a spring holds the spindle against a stop.

The retention achieved by means of a preloaded spring is less stable over time: such a spring, which must work with varying forces due to the shocks to which the watch is subjected, fatigues and wears out, as does every component subjected to the impact forces on the stop.

Furthermore, reproducible production of such springs is difficult. Setting tolerances can also lead to significant variations in the preload value. Consequently, performance becomes less stable over time, and the shock-absorbing effect deteriorates over the life of the watch.

In short, the main problems encountered with resilient mechanical retention systems are wear of the components caused by repeated mechanical forces and the need to achieve close tolerances (which are therefore very costly).

Therefore, it is still difficult to ensure the axial retention of the timepiece spindle by a durable anti-vibration mechanism.

European Patent Application No. 2,450,758, in the name of MONTRES BREGUET SA, discloses a method for orienting a watch component made of a magnetically permeable or magnetic material, comprising two ends. Two magnetic fields are formed on either side of the ends, each attracting the component toward a pole shoe. The magnetic fields are of uneven intensity around the component, generating a difference in force thereon and pressing one of the ends against the contact surface of one of the pole shoes, while the other end is held at a distance from the other pole shoe. This application also discloses an electrostatic variant based on the same principle. This application also relates to a magnetic pivot (or electrostatic variant) comprising such a watch component, comprising a guide device having two pole shoe surfaces at an air gap distance greater than the center distance between the ends, each pole shoe surface being arranged to be attracted by a magnetic field transmitted by one of the ends, or to generate a magnetic field that attracts one of the ends, such that the magnetic forces exerted on the two ends have different intensities, thereby attracting one end to contact only one of the pole shoe surfaces. In this patent, the main function of the magnets is to radially realign the spindle. Two magnets, one at each end, which generate a magnetic field on either side of the spindle are essential for its operation.

European Patent Application No. 2,450,759 in the name of MONTRES BREGUET SA discloses a mechanical anti-shock device associated with a magnetic pivot, in particular a magnetic (or electrostatic) anti-shock device for protecting a timepiece component mounted to pivot between a first end and a second end. It comprises, on one hand, on each side of these ends, means for guiding the pivoting of the first end or for attracting the first end and keeping it resting on a first pole shoe, and, on the other hand, near the second pole shoe, means for guiding the pivoting of the second end or for attracting the second end towards the second pole shoe, and these means for guiding the pivoting of the first end or for attracting the first end, on the one hand, and for guiding the pivoting of the second end or for attracting the second end, on the other hand, are movable in a given direction between stops.

French Patent No. 1,314,364, in the name of HELD, discloses a magnet assembly for contactless magnetic levitation of a timepiece pivot, in which a ring magnet is located in a circular disk that passes through the center. This levitation is achieved by magnetic repulsion, thus providing contactless operation. In a first variant, the magnet is radially magnetized, with one pole located on the inner generatrix of the hole and the other on the outer generatrix. In a second variant, the magnet is axially polarized, with two polar regions distributed on two circular planar surfaces of the disc, and a mandrel of a movable assembly, magnetically held and guided, passes through the center of the hole of the annular magnet, the mandrel consisting of a tube with a thin non-magnetic wall containing a supercoercive material magnetized integrally with two poles of opposite sign at the two ends or in two segments separated by a gap, the opposite ends of the two segments being housed in a protective tube with poles of the same sign, assembled with a fixed disc/magnet, wherein the radial polar axis and poles of opposite sign are assembled on the axially magnetized disc, the gap separating the two segments forming a core of a tubular mandrel of similar thickness to the associated disc and placed in the central hole of the disc, so that the end of the axial magnet extends slightly inside the hole and the two circular planar surfaces define the height of the cylinder or magnetized disc.

DE patent application 10062065A1 in the name of SIEMENS, WO patent application 2011095646A1 in the name of FERREIRO GARCIA RAMON, and Japanese patent application S5659027A in the name of SEIKO all disclose utilizing magnetic repulsion to achieve operation in suspension.

Summary of the Invention

The present invention proposes to define a mechanism for holding a timepiece arbour in position capable of ensuring a stable anti-shock effect over time and that is reproducible.

To this end, the present invention relates to a timepiece subassembly for a watch, comprising a main structure and a spindle, the spindle being pivotally movable about a pivot axis inside at least one housing of the main structure, the spindle comprising at least one surface made of a magnetized or magnetically conductive material, and the main structure comprising at least one pole shoe, the pole shoe being arranged to form at least one magnetic field for axial and/or magnetic retention of the spindle adjacent to at least one of the surfaces, the timepiece subassembly being characterized in that at least one of the pole shoes is arranged to cooperate with at least one of the surfaces along the pivot axis in an axial and radial attraction or repulsion manner so as to hold the spindle against the housing in an operating position and allow the spindle to travel a certain distance during vibrations in order to absorb radial vibrations and return the spindle to the operating position after the vibrations cease; and that at least one of the pole shoes is arranged to form at least one of the magnetic fields adjacent to at least one of the surfaces, the magnetic field tending to attract the spindle radially toward the wall of the housing.

The invention also relates to a movement comprising at least one such subassembly.

The invention also relates to a watch comprising at least one such subassembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent upon reading the following detailed description made with reference to the accompanying drawings, in which:

Figure 1 shows a schematic perspective view of a timepiece subassembly according to the invention comprising a spindle, the spindle being radially retained by magnetic attraction or repulsion in a first orifice by a first pole shoe forming a generally tubular section, the axis of the spindle being retained on a pivot axis corresponding generally to the axis of the first orifice; the spindle being axially retained by a second front pole shoe in a chamber defined here by a second orifice comprised in a generally tubular limiting sleeve; this subassembly is shown without any position stop.

FIG. 2 shows a schematic cross-sectional view of the subassembly of FIG. 1 .

FIG. 3 shows a schematic top view of the subassembly of FIG. 1 .

4 and 5 show another similar subassembly in cross-section and top view, respectively, where the first pole piece is revolved about the spindle.

Figure 6 shows a schematic cross-sectional view of a subassembly for a watch exterior or movement according to the invention, in a first variant comprising a radial mechanical guiding system and at least one magnet ensuring axial retention of the spindle in the axial direction; this subassembly comprises a structure having a lower wing comprising a magnet at the bottom of the housing; the housing receives the spindle which is subjected to a magnetic attraction in a field direction parallel to the axial direction; the structure comprises an upper wing limiting the displacement of the insert and forming a safety stop above the spindle.

FIG. 7 shows an inverted configuration in a similar manner to FIG. 1 , wherein the safety stop is below the spindle and a friction surface is added to the stop.

FIG8 shows a schematic cross-sectional view of a magnet and a magnetically attractable portion forming a structure and a spindle each comprising a friction layer or a wear layer on their respective contact surfaces.

Figure 9 shows a schematic cross-sectional view of a structure with a magnetized housing receiving a tack-shaped magnet, which presses a spacer forming part of the spindle, the spacer being constrained and pressed against the structure by the magnet and clamped between the head of the magnet and a fixing element.

10 shows a schematic partial cross-sectional view along its axis of a spindle comprising several magnets whose polarity is indicated by hatching or cross-hatching and which is movable between other fixed magnets comprised in a structure in which the spindle can move.

FIG. 11 shows another configuration of a magnet-carrying mandrel between the other fixed magnets of the structure.

Figure 12 shows a schematic partial cross-sectional view of a linear structure fixed in the z direction, wherein the linear structure comprises an alternating arrangement of paramagnetic or ferromagnetic parts on the one hand and diamagnetic parts on the other hand, represented by hatching and cross hatching, respectively, and wherein a cylindrical core shaft including a permanent magnet (not shown) can be aligned along the stationary structure.

FIG13 shows a schematic front view of a watch comprising a movement having such a subassembly.

Figure 14 shows a schematic partial cross-sectional view of the pivot axis of a watch subassembly according to the present invention passing through its spindle, the watch subassembly comprising a spindle pivotally movable within a structure, wherein the spindle generates an axial field at its lower end and a roughly conical field around the pivot axis having a first strength in the direction of the pivot axis, and wherein the structure within which the spindle can move comprises a series of regions for generating the conical field, which tend to be opposite to the field generated by the spindle and which have gradually increasing strength as they approach the lower part of the spindle's stroke from the operating position of the spindle shown in Figure 14A; each of these field regions of the structure forms a virtual catch for braking the spindle during its downward stroke.

Figure 14B shows the subassembly of Figure 14A after a shock or large acceleration, with the spindle beginning its stroke toward the lower end of its stroke (not shown) and in a position where the spindle crosses a first field barrier represented by a single-line arrow, which is substantially symmetrical and opposite to the spindle's own conical field, and the spindle reaches a second field barrier, which has a higher axial strength than the first field barrier and is represented by a double-line arrow.

Figure 14C shows the same subassembly in a case where the kinetic energy imparted to the spindle is high and enables it to cross the second field barrier and the spindle reaches the third field barrier, which has a higher axial strength than the second barrier and is represented by a triple-line arrow and is sufficient in this case to stop the axial travel of the spindle.

FIG. 14D shows the mandrel subsequently raised to its operative position of FIG. 14A under the influence of the repulsive field to which it is subjected.

Figure 15 shows a similar arrangement in a similar manner to Figure 14, but in which the central shaft generates only axial end fields and in which the third conical barrier at the lower end of the stroke is replaced by an axial field barrier of similar strength and the central shaft has a series of descents and ascents on its axis similar to that of Figure 14.

FIG. 16 shows a structure including a housing in which the spindle is movable, with a symmetrical arrangement corresponding to the variant of FIG. 15 at the lower and upper ends of the spindle and the housing.

FIG. 16A shows a variation in a similar manner to FIG. 16 , in which the field produces an attractive force rather than a repulsive force.

FIG. 16B shows a variation in a similar manner to FIG. 16 , in which an attractive force is generated in the radial field rather than a repulsive force, while the axial field of the structure generates a repulsive force.

17 shows, in a perspective view in FIG. 17A and in a top view in FIG. 17B , the subassembly according to FIG. 16 , comprising a lateral cutout parallel to the pivot axis of the spindle, which allows insertion and removal of the spindle.

Figure 18A is a schematic perspective view of a mechanism utilizing the system of Figure 12, wherein the central shaft has in its middle portion a dark permanent magnet arranged adjacent a linear structure, the linear structure here in the form of a concave shell with an alternating arrangement of diamagnetic and paramagnetic/ferromagnetic regions; Figure 18B is a cross-sectional view of the assembly of Figure 18A, and Figure 18C shows the polarity generated by the presence of the permanent magnet fixed to the central shaft and the magnetic properties of the regions on the shell; the central shaft provided with the permanent magnet is therefore subjected to forces similar to those of the schemes of Figures 10 to 12, but here the forces are generated by the diamagnetic and paramagnetic/ferromagnetic regions.

19A and 19B are similar to FIGs. 18B and 18C, but for a system where retention is achieved by mechanical contact, with the hatched portions being stationary.

The graph of FIG. 20 shows the variation of the magnetic force exerted between two cylindrical magnets of equal power and diameter on the ordinate as a function of the ratio of their relative heights on the abscissa, the value 0.5 corresponding to the case where they have equal heights.

The curve of Figure 21 shows the variation of the magnetic force exerted between a cylindrical magnet and a cylindrical ferromagnetic part of the same diameter on the ordinate as a function of the ratio of their relative heights on the abscissa, the value 0.25 corresponding to the case where the ferromagnetic part is one-third of the magnet.

22 shows a schematic partial cross-section of a timepiece movement comprising a subassembly according to the invention, the central shaft of which is attracted axially by the pole shoe and whose end is in frictional contact with the front portion of the pole shoe.

DETAILED DESCRIPTION

The effects of mechanical forces in a component depend on a large number of parameters, which often have wide tolerances. The consequences of friction and wear are particularly difficult to control because they depend heavily on the surface condition and physical properties of the materials used.

These properties, in turn, depend on the alloy used and the methods implemented, particularly heat treatment, surface treatment, and ion implantation. The cumulative tolerances of the different parameters of the methods and materials make it impossible to know and accurately control these physical properties. Therefore, due to such tolerances, reproducibility cannot be guaranteed. In addition, narrowing the tolerance range - which makes it possible to obtain better reproducibility of the phenomenon - leads to excessive costs for mass production.

Maxwell's equations adequately describe the theory that determines magnetic interactions, and the remaining unknowns arise from the increasingly well-controlled magnetic materials used and the difficulty of solving these equations analytically and numerically to the lowest possible approximation. However, from a macroscopic perspective, these errors are low enough to make magnetic systems intrinsically reliable.

The invention proposes an anti-vibration holding system for a timepiece arbour that is stable over time under the influence of magnetic and/or electrostatic fields.

The anti-vibration holding system is described in more detail by means of a non-limiting example of a magnetic application. The invention can also be implemented by using an electrostatic field, in particular by using an electret, or even by combining a magnetic field and an electrostatic field.

"Arbor" here refers to any timepiece component arranged to pivot about a theoretical pivot axis. Here, the invention is primarily described with respect to the shaft-like portion of such a component, or a wheel set or the like. In the case of a balance wheel, for example, particular attention will be paid to the end of the shaft-like portion of the balance wheel. The invention is explained in a simplified manner by means of a rotating arbor comprising one or more cylindrical shoulders. However, this description is not restrictive; the invention can be applied to any type of component, such as a pallet fork, escape wheel, wheel, pinion, or other element.

In these examples, it is proposed to construct a spindle holding system using magnetic forces, thereby exploiting the force induced on a piece of magnetized material surrounded by a magnetic field. This force is given by the following law (for the interaction between a magnet and a magnetic component):

F＝(M·▽)B (1)

where M is the magnetization of the material, B is the external magnetic field, and all values in (1) are vector quantities.

The principle is to position one or more magnets on the fixed part and to exploit the magnetic force to which a ferromagnetic (attraction), diamagnetic (repulsion) or paramagnetic (attraction) component to be fixed is subjected. This component is thus subjected to an attractive or repulsive force that can be used to hold it in place.

A first variant in Figures 1 to 3 consists in using magnetic forces to force the spindle in three directions, for example by keeping the spindle in contact inside a triangle (positioning stop) that positions the spindle. This contact can also be done directly on the permanent magnet.

The second variant in FIG4 , with radial mechanical guidance and magnets ensuring axial retention, relates to the case where the magnetic force is used to exert a force on the spindle in one or two of the three directions, while the mechanical guidance is used to limit the movement of the spindle in the other directions. Typically, the radial guidance can be achieved via a sleeve, while the spindle is retained axially by the magnets.

Of course, the number of magnets used can vary from one variant to another. For example, a design can be envisaged that uses a crown of several magnets instead of the single magnet for axial retention in the z-direction in Figures 1 to 4. This has the advantage that imperfections in the component are averaged out and that the forces, in particular the (magnetic) forces, are exerted over a larger radius.

In the magnetic applications described below, retention systems are created that utilize forces, in a broad sense, induced on a piece of magnetized or ferromagnetic material located in a magnetic field - i.e., forces or torques. This force depends on the magnetization of the material or its magnetic permeability, as well as the strength of the local magnetic field. In a specific embodiment, one or more magnets are positioned on a fixed part called a structure and/or on a mandrel. The mandrel is subjected to (or generates, if it is magnetized and cooperates with a magnetized or non-magnetized or ferromagnetic environment) an attractive or repulsive force that can be used to hold it in place.

For light components, the magnetic force itself may be sufficient to hold the component in place despite vibrations, if the available space allows for the presence of one or more magnets capable of generating a sufficient magnetic field.

However, in most cases, this force is too low. When the magnetic force is too low to resist vibrations, a safety stop can be introduced to limit excessive displacement, as shown in Figures 6 and 7, which represent two configurations of the type of Figure 4 with safety stops (one above the component and one below) and a potential contact area marked 5. Magnetic retention is therefore used to counteract small vibrations with an amplitude limit, after which the component moves away and reaches the stop. This operating mode has the advantages of a retention system using a spring while causing less vibration when returning to its original position. In fact, unlike a spring system, a magnetic system applies a force that decreases as the component moves away from its holding position. The energy stored during an unexpected vibration (which is released when the component returns to its original position) is therefore lower.

This force can also be generated by two magnets. Figures 20 and 21 show the magnetic force Fm in Newtons that can be generated by a system with two magnetic bodies - two magnets in Figure 20 or one magnet and a ferromagnetic part in Figure 21, respectively - according to the ratio h1/h2 of the relative sizes of these two bodies.

In another variant, the magnetic system not only performs a holding function but also facilitates a positioning/repositioning function, as shown in Figures 10 and 11. In the first case of Figure 10, an additional force must be applied to overcome the magnetic repulsion of the magnets, and once the system is in place, it is held there in the axial z direction; this system is particularly advantageous when combined with the introduction of jewels or any other friction surfaces to minimize friction from radial contact. The second case of Figure 11 is a magnetic recentering system, in which a spindle containing permanent magnets is held against a linear structure composed of magnetically attractive and repelling parts. These parts can also be made of permanent magnets. The radial retention of this system is magnetic, thanks to the attractive part (with the possible variations given above); the component is magnetically recentered after each vibration. This system can be easily adapted to angular degrees of freedom.

The linear structure of FIG. 12 with the magnetic attraction and repulsion areas may also be located directly on the arbour, with the permanent magnets located on a fixed part of the movement.

Therefore, different geometries can be used.

It is also possible to use magnetic forces to exert forces in three directions on an element external to the movement or watch, for example by holding it in contact within a concave trihedron that positions it and also forms a set of position stops. The magnetic element can be retracted relative to the contact surface. Contact can also be achieved directly on the surface of the magnetic member.

One variant involves the case where magnetic forces are used to exert a force on the element in one or two of the three directions, while mechanical guidance is used to limit the displacement of the element in the other directions.

The invention is therefore described more particularly with respect to the axial damping of the arbour.The pivoting of the arbour may be conventional, by guidance in jewels or bearings, or of the magnetic or other type, in particular a combination thereof.

For each of these variants, a safety stop can be introduced to limit the displacement of the spindle and prevent excessive travel when the magnetic force is too low to resist shocks. Thus, magnetic retention is used to counteract small shocks, which have a certain amplitude, starting from which the magnetically retained spindle will move away and encounter a mechanical safety stop. This operating mode has the advantages of a retaining system using springs, while causing less shock when returning to the original position. In fact, unlike a spring system, the magnetic system exerts a force that decreases as the spindle moves away from the operating position in which it is retained. The energy stored during an unexpected shock and released when the element returns to its original position is therefore lower.

In an advantageous embodiment of the invention, the cooperation between the magnetic and/or electrostatic fields present in the structure and/or the mandrel is sequenced and comprises an electromagnetic barrier which depends on the relative position of the mandrel and the structure and over which in the event of a shock all or part of the kinetic energy of the mandrel is utilized.

The opposing forces can be generated by two magnets, or by one magnet in proximity to a ferromagnetic (attraction), diamagnetic (repulsion), or paramagnetic (attraction) part.

The mandrel to be held in position may be ferromagnetic, diamagnetic or paramagnetic in nature and located in the vicinity of a magnet, or may comprise one or more magnets or magnetised or charged regions in nature.

In the case where the force is generated by two magnets, they can operate by attraction or repulsion, with attraction theoretically resulting in slower aging of the magnetic system. However, the repulsion mode is easier to implement for vibration reduction at the spindle end, and this non-limiting mode is described in the illustrated example.

The vibration damping feature of the present invention achieved by magnetic or electrostatic means is very good for low or medium amplitude vibrations. If one envisages using this technology to completely absorb the additional kinetic energy of the spindle in the event of vibration, this would obviously be at the expense of space. Therefore, the present invention is preferably combined with a conventional mechanical stop, which may be a simple stop, or a bearing surface of a spring that does not come into contact with the spindle during low or medium amplitude vibrations. Preferably, due to its fragility, each magnet surface is protected by another surface included in the spindle or in an associated structural element, as the case may be. Thus, the contact between opposing members such as the main structure 100 and the spindle 10 may be that of a portion of the spindle to be retained against a position stop, which does not necessarily have to be magnetic.

In a preferred application of the invention, the magnetic or electrostatic means implemented to form an axial anti-vibration system for the spindle also serve to ensure axial retention of the spindle in its operating position. Obviously, contact is completely avoided only in the configuration utilizing magnetic repulsion, as in FIG16 . In most other cases, even with magnetic repulsion, contact on the spindle is unavoidable. Circumferential friction dissipates more energy than friction on the front.

The invention is particularly suitable for holding the spindle axially and radially in contact.It is not always possible to implement a frictionally advantageous configuration with remote axial and/or radial holding of the spindle.

In this context it should be pointed out that the magnetic or electrostatic cooperation between the spindle and the receiving structure is not necessarily only axial.

Advantageously, this cooperation ensures radial maintenance, tending constantly to align the spindle 10 on its theoretical pivot axis DA. Thus, even if the conventional pivoting guidance of the spindle 10 is not perfect, this guidance is optimized by the effect of the magnetic or electrostatic field tending constantly to realign the spindle 10 on its axis DA.

In Figures 1 to 4, contact is not shown; this contact can be the direct abutment of a magnet against the spindle (or, where appropriate, a fixed magnet against a magnet of the part to be held in contact), as shown in Figure 8, or the abutment of a part of the component to be held against a position stop (which is not necessarily magnetic), as shown in Figure 9. The surfaces held in contact can be adapted to optimize their friction and mechanical properties.

In an alternative to conventional guidance of the spindle inside the structure by means of contact surfaces, these surfaces can be adapted to optimize their friction and/or mechanical and/or wear characteristics. The surface layer shown in FIG8 , which can also be realized by a variant of FIG9 or other variants, can be composed, for example, of corundum, diamond or a protective coating. This surface layer can also be made of a material that combines specific friction and magnetic properties, such as, in particular, tungsten carbide containing a cobalt binder.

For light components, the magnetic force itself may be sufficient to hold the component in place despite vibrations, if the available space allows for the presence of one or more magnets capable of generating a sufficient magnetic field.

Different geometric configurations can be used. In the example described, the spindle holding system is constructed using magnetic forces (forces and/or torques), thereby taking advantage of the forces induced on a piece of magnetized material surrounded by a magnetic field. To achieve this, one or more magnets are preferably positioned on the fixed part and use is made of the magnetic forces to which the ferromagnetic (attraction), diamagnetic (repulsion) or paramagnetic (attraction) part that must be fixed is subjected. This component will thus be subject to a repulsive or attractive force that can be used to hold it in place. The opposite relative positioning is also possible.

The variants shown in Figures 1 to 3 include using magnetic forces to exert forces on the spindle 10 in three directions, for example by retaining the spindle 10 within a trihedron that positions it, or by contact with a position stop (not shown), and/or by magnetic interaction with a permanent magnet. For example, any spindle 10 cooperates with a first structure 11 radially surrounding its first upper shoulder 16 and with a second structure 12 when the spindle is axially aligned on the pivot axis DA. In a particular embodiment, these first and second structures 11, 12 are magnets. A third structure 13 includes an orifice 15 that limits the radial movement of the lower shoulder 17 of the spindle 10.

Another variant shown in Figures 4 and 5 shows a case in which the spindle 10 is forced in one or two of three directions, here in the axial direction corresponding to the pivot axis DA, by means of magnetic forces, while the displacement of the spindle 10 in the other directions is limited by mechanical guidance. Generally, radial guidance can be achieved by means of a sleeve in the orifice 14 of the first structure 11, while the spindle 10 is axially retained by magnets included in the second structure 12.

Of course, the number of magnets used can vary from one variant to another. Thus, by replacing the single magnet used for axial retention in the axial direction in the examples of Figures 1 to 5 with a structure comprising a crown of several magnets, there is the advantage of averaging out imperfections in the component and exerting the force over a wider radius. This can be an advantage if the mechanism is designed to exploit eddy current dissipation to increase the frictional capacity of the magnetic equivalent of the friction spring.

Therefore, the preferred but non-limiting solution uses the magnetic attraction between two magnets or between a magnet and a magnetically conductive component, in particular a ferromagnetic component. This provides better stability of the component and better position control.

It should be understood that formula (1) is only valid for determining the force between a magnet and a magnetic component (it is not valid for determining the force between two magnets), and in most cases, the magnetic component is ferromagnetic and will therefore be magnetized in concert with the magnet: in this case, the force is an attractive force. Only in the case where the magnetic component is diamagnetic will there be a repulsive force between the magnet and the component, but this force is 10 to 100 times lower than the force that can be obtained by attraction.

The solution shown in Figures 1 to 4 utilizes only attractive forces, the direction of which tends to move the parts together, said forces being negative both in the magnet-ferromagnetic part variant and in the variant with two magnets.

Only FIG. 5 corresponds to a solution in which attractive and repulsive forces combine to stabilize the position of the member.

The scheme utilizing repulsive forces allows all or a portion of the vibration energy to be dissipated through magnetic repulsion rather than mechanical vibration.

For lightweight spindles, if the available space allows for the inclusion of a sufficient number of magnets, the magnetic force alone is sufficient to retain the spindle in the event of vibration. However, in most cases, this force is too low due to space constraints. When the magnetic force is too low to resist vibration, a safety stop can be introduced, as shown in Figures 6 or 7, to limit excessive displacement. These two configurations show safety stops, one above the component in Figure 6 and one below in Figure 7. Therefore, magnetic retention is preferably used to resist small vibrations with a limited amplitude, after which the component breaks free from the magnetic influence and reaches the mechanical stop under the influence of the remainder of its kinetic energy. This operating mode has the advantages of a retaining system using a spring, while causing less vibration when returning to the normal operating position. In fact, unlike a spring system, this magnetic system exerts a force that decreases as the spindle moves away from the operating position in which it is retained. The energy stored during an unexpected vibration (which is released when the component returns to its original position) is therefore lower.

In Figures 1 to 5, contact is not shown. This contact can be direct contact between the magnet and the mandrel as shown in Figure 8, or a portion of the mandrel to be held against a position stop (which is not necessarily magnetic) as shown in Figure 9. The surface that is kept in contact can be adapted to optimize its friction and mechanical properties. For example, the surface can be corundum, diamond, sapphire or a protective coating. The surface can also be a material that combines favorable friction and magnetic properties, such as tungsten carbide containing a cobalt binder.

In another variant, the magnetic system has this holding function and also facilitates the positioning/repositioning function, as shown in Figures 10 to 12.

In the first case of Figures 10 and 11, when the spindle is inserted axially into the orifice of the structure, additional force must be applied to overcome the repulsion of the magnets, but once the system is in place, it is held there in the axial direction DA. Such a system is particularly advantageous when combined with the introduction of a jewel (or any other friction surface) in order to minimize friction from radial contact without using friction.

The second case of FIG12 is a magnetic realignment system in which the spindle 10 comprises a permanent magnet and is held against a linear structure consisting of magnetic attraction and repulsion parts. These parts can also be made of permanent magnets. The radial retention of this system is magnetic by means of the attraction parts and has the possible variants given above; the spindle is magnetically realigned after each vibration. This system can be easily adapted to angular degrees of freedom. This linear structure with magnetic attraction and repulsion areas can also be located directly on the spindle 10, with the permanent magnets on this structure connected to the fixed parts of the watch movement.

Figures 18A, 18B, and 18C illustrate a mechanism utilizing the system of Figure 12. Figures 18A and 18B illustrate a spindle with a permanent magnet, arranged near a linear structure (here in the form of a housing (not necessarily a rotating structure)) comprising an alternating arrangement of diamagnetic and paramagnetic/ferromagnetic regions. Figure 18C illustrates the polarity generated by the presence of the permanent magnet (fixed to the spindle) and by the magnetic properties of the regions on the housing. The spindle provided with the permanent magnet is thus subjected to forces similar to those of the embodiment of Figures 10 to 12, but here these forces are generated by the diamagnetic and paramagnetic/ferromagnetic regions.

19A and 19B are similar to FIGs. 18B and 18C, but for a system where retention is achieved by mechanical contact, with the hatched portions being stationary.

Returning to FIG. 10 , the magnet of one of the two components (the spindle or the sleeve) is preferably rotatable to ensure proper operation of the spindle when it is rotating. Regarding the anti-vibration function, in the case of non-rotating magnets, the response of the system is not isotropic. This is not necessarily inconvenient in the case of a transient phase, so other configurations can be envisaged:

- the spindle magnets are rotating (while the sleeve magnets are not), so the direction in which the anti-seismic effect is greatest is fixed to the movement, which may correspond, for example, to the direction that statistically receives more shocks;

- the magnets of the sleeve are rotational (while those of the arbour are not), so the direction in which the anti-seismic function is greatest is fixed on the arbour; this direction may correspond to a radial position of the central axis in which the force must be applied better than in other positions (for example due to the presence of a fixing element on the arbour that is not rotationally symmetrical and would interfere with another element of the movement);

- One of the two configurations above, but in which the non-rotating magnets are no longer located on either side; thus, maintaining mechanical contact on one side ensures the radial positioning of the spindle.

These solutions allow more axial positioning (where mechanical guidance is used for the radial part) than radial positioning, since they work by attraction. This characteristic makes them unstable in the case where they are used for radial centering.

14 to 17 are used for radial re-centering with repulsion, wherein the axial stop positioning is achieved by means of magnetic forces. A variant (not shown) with magnetic attraction of the axial ends is particularly advantageous.

The variant operating by magnetic attraction suffers from imprecise radial centering: the spindle is in mechanical contact with one of the sleeve walls, a wall that may vary during operation, but this variant also allows the spindle to be pressed axially against the stop by a restoring force that depends on its position in its sleeve. A variant with non-rotating magnets, similar to that of FIG. 1 , allows the spindle to always be pressed radially against the same face, and its position is therefore less subject to variations.

Another variation includes adding a front magnet to the fixed structure to assist in retaining the spindle axially at one of its ends.

Another variant with a force that decreases instead of increases with the displacement of the spindle in the sleeve makes it possible to obtain a very strong holding force, with the contribution of the magnetic force decreasing with greater amplitudes of vibration (here the stop is responsible).

Various types of magnetic potential energy curves can be envisaged, in particular a stepped variant, in which more and more energy is absorbed as the spindle moves towards its stop. Another variant comprises a real barrier, which technically absorbs energy only temporarily, since the energy is returned as soon as the spindle leaves the barrier area.

While the variation shown in FIG14 relates to a structure within which the spindle can move, the structure comprising a series of regions producing a conical magnetic field tending to oppose the magnetic field produced by the spindle and having increasing strength as they approach the lower part of the spindle's travel, starting from the spindle's operating position, it will be appreciated that other variations may involve:

- a series of regions that generate a field that tends to align with the field generated by the mandrel;

- and/or a field of decreasing intensity towards the lower part of the spindle stroke.

A configuration in which the magnetic force depends on the position of the spindle in the sleeve (with increased strength during large shocks) is advantageous. In this variant, the dependence of the magnetic force can also be formed in a manner similar to a mechanical spring (increasing as the spindle moves away from its equilibrium position).

Figure 22 shows the situation where the spindle is axially attracted by the pole shoe, with the end of the spindle in frictional contact with the front of the pole shoe.

The lateral retention of Figures 1 to 3 is chosen to be local in order to maintain mechanical contact and thus exploit the concept of anti-seismic. For low-amplitude shocks, the spindle - usually the balance staff - does not leave its original position (it is kept in a preferred angular orientation) and only moves above a certain threshold. The drawback of the lateral solution is the increased friction (on the radius of the spindle, rather than on the radius where friction is reduced). However, this friction can be used to dissipate energy, usually to suppress the floating movement of the pointer.

Naturally, although in the examples the spindles and magnets are described by magnetic attraction, it is entirely possible to form the same system by repulsion, which thus creates contact on opposite sides.

In order to protect the outside of the watch - in particular the user and certain sensitive components - from the magnetic field of such a system and to improve the efficiency of the retention system, it is possible and advantageous to insert a ferromagnetic shield or to use a case intermediate in this way.

More specifically, the invention relates to a horological subassembly 200 for a watch, comprising a main structure 100 and an arbour 10. This arbour 10 is pivotally movable inside at least one housing 14, 15 of the main structure 100 about a pivot axis DA.

The mandrel 10 comprises at least one surface 16, 18, 21, 22 made of a magnetizable or magnetically conductive material or a charged or electrostatically conductive material. "Magnetically conductive" here means ferromagnetic or diamagnetic or paramagnetic material.

In order to cooperate with the spindle 10, the main structure 100 includes at least one pole shoe 11, 12, 31, 32, which is arranged to form at least one magnetic field or at least one electrostatic field near at least one such surface 16, 18, 21, 22 for axially and/or magnetically holding the spindle 10 relative to the pivot axis DA.

With the mandrel 10 held axially, the field is substantially rotary about the pivot axis DA.

In a variant, the main structure 100 comprises at least one pole shoe 11 , 12 , 31 , 32 arranged to form, in addition to the field for axially retaining the mandrel 10 , at least one magnetic field or at least one electrostatic field near at least one such surface 16 , 18 , 21 , 22 for radially retaining the mandrel 10 .

More specifically, these fields ensure both axial and radial retention of the mandrel 10 .

According to the invention, at least one such pole shoe 11, 12, 31, 32 is arranged to cooperate with at least one such surface 16, 18, 21, 22 along the pivot axis DA in an axial and/or radial attractive or repulsive manner to absorb vibrations and return the spindle 10 to the operating position after the vibrations have ceased.

According to the invention, at least one pole shoe 11 , 12 , 31 , 32 is arranged to form, adjacent to at least one such surface 16 , 18 , 21 , 22 , at least one such magnetic or electrostatic field tending to attract the spindle 10 radially towards the wall of the housing 14 , 15 .

In another variant, the field thus generated varies along the pivot axis DA and is arranged to exert on the spindle 10 a resisting force resulting from cooperation between at least one pole shoe 11 , 12 , 31 , 32 and at least one surface 16 , 18 , 21 , 22 by magnetic attraction or repulsion.

More specifically, at least one such pole shoe 11, 12, 31, 32 is arranged to cooperate with at least one such surface 16, 18, 21, 22 along the pivot axis DA in an axially attractive or repulsive manner so as to maintain the spindle 10 in the axial operating position without any vibrations or external disturbances.

More specifically, at least two pole pieces 11, 12, 31, 32 cooperate in a geometrically opposed manner with at least two corresponding surfaces 16, 18, 21, 22 to exert opposite and equal axial forces on the spindle 10. It will be understood that, in the normal operating position, not all surfaces of the spindle 10 necessarily cooperate with all pole pieces of the main structure 100; in fact, the relative cooperation between certain surfaces and certain pole pieces only exists in certain relative axial positions of the spindle 10 with respect to the main structure 100.

Of course, the surface of the mandrel can be a pole shoe configured to form such a magnetic field or such an electrostatic field, just as certain pole shoes of the structure can include surfaces made of magnetized material or magnetically conductive material or charged material or electrostatically conductive material: both the mandrel 10 and the main structure 100 can include areas that generate fields, and/or passive areas that react to magnetic fields and/or electrostatic fields.

In a variant of the invention, in magnetic applications, the axial component of the resulting magnetic field along the pivot axis DA, which ensures axial anti-seismic attraction or repulsion, preferably has an intensity greater than 0.55 Tesla in the case of a steel spindle with a mass of 60 mg.

Electrostatic applications require fields that limit their application to mandrels of very small mass, much less than 60 mg, in particular less than 10 mg.

In a particular embodiment to minimize friction, at least one magnetic or electrostatic field tends to radially attract or repel the spindle 10 at a distance from the walls of the housings 14, 15 and align the spindle 10 on the pivot axis DA. More specifically, at least one of the pole shoes 11, 12, 31, 32 is arranged to form such a field adjacent to at least one such surface 16, 18, 21, 22.

In another variant, at least one magnetic or electrostatic field tends to attract the spindle 10 radially towards one wall of the housing 14, 15. More specifically, at least one of the pole shoes 11, 12, 31, 32 is arranged to form such a field adjacent to at least one such surface 16, 18, 21, 22.

In an advantageous embodiment, the spindle 10 is braked axially along the pivot axis DA only by magnetic or electrostatic potential energy, which varies along the pivot axis DA and generates a resisting force resulting from the attractive or repulsive cooperation between at least one pole shoe 11, 21, 31, 32 and at least one surface 16, 18, 21, 22.

More specifically, the curve of this potential energy is such that the resisting force increases or decreases continuously during the travel of the spindle 10 along the pivot axis DA.

More specifically, to ensure the conversion of kinetic energy transferred to spindle 10 during acceleration or shock, spindle 10 is braked axially along pivot axis DA solely by a potential energy curve that forms at least one magnetic or electrostatic barrier, resulting from the attractive or repulsive interaction between at least one pole piece 11, 12, 31, 32 and at least one of the surfaces 16, 18, 21, 22. This barrier forms a virtual annular jaw designed to brake or stop the travel of spindle 10 along pivot axis DA. Overcoming such a barrier during shock absorbs a portion of the kinetic energy of spindle 10. Depending on the configuration of the potential energy curve, this energy is either returned if the barrier forms a potential energy peak between an ascending and a descending potential energy slope, or accumulated if the potential energy curve is stepped or sawtooth-shaped, with multiple steps each limited by such a potential energy barrier.

More specifically, the spindle 10 is braked axially along the pivot axis DA only by a plurality of such barriers; crossing each barrier absorbs a portion of the kinetic energy of the shock, each barrier thus forming a boundary of a potential energy level.

More specifically, these barriers are successive and have a magnetic or electrostatic field strength that increases along the pivot axis DA from the operating position of the spindle 10 towards a mechanical stop included in the main structure 100 that forms the end of travel of the end of the relative spindle 10 .

In a variant, the mechanical stop is paired with a magnetic stop or forms the magnetic stop itself.

In one particular embodiment, the mandrel 10 is cylindrical.

In a particular embodiment, at least one shell 14 , 15 of the primary structure 100 is cylindrical. More specifically, the primary structure 100 comprises a single aperture for receiving the mandrel 10 .

In one variant for the lateral insertion of the mandrel 10 , the primary structure 100 comprises a lateral cutout 19 extending parallel to the pivot axis DA and dimensioned to allow the lateral insertion and removal of the mandrel 10 .

In one variation for axial insertion of the mandrel 10 , the primary structure 100 comprises an end cutout 190 sized to allow insertion and removal of the mandrel 10 along the pivot axis DA.

In a particular variation, the primary structure 100 includes a first structure 11 comprising at least one first housing 14. A spindle 10 is pivotally movable at least within the interior of the first housing 14. The first structure 11 generates a magnetic field or an electrostatic field that substantially revolves about a pivot axis DA within the first housing 14, such that the spindle 10 is subjected to a force tending to align the spindle 10 along the pivot axis DA. The primary structure 100 includes a magnetized or charged blocking surface 120 in a second housing 15 disposed on the first structure 11 or the second structure 12 included in the primary structure 100, which is configured to axially attract or repel a magnetized or charged front surface 18 included in the spindle 10 along the pivot axis DA. In a magnetic variation, for a steel spindle having a mass of 60 mg, the magnetic field strength between the front surface 18 and the blocking surface 120 is greater than 0.55 Tesla.

More specifically, when the spindle 10 is located in the first housing 14, the at least one front surface 18 is revolutionized about a spindle axis AA of the spindle 10 that is aligned with the pivot axis DA.

More specifically, arbour 10 comprises two such front surfaces 18 opposite one another, and timepiece subassembly 200 comprises two of said blocking surfaces 120 , each blocking surface 120 being arranged to attract or repel one such front surface 18 .

More specifically, the spindle 10 includes at least one such front surface 18 at a distal end along a spindle axis AA of the spindle 10 that is aligned with the pivot axis DA when the spindle 10 is located in the first housing 14 .

More specifically, the mandrel 10 includes one such front surface 18 at each of its distal ends along the mandrel axis AA.

In a particular variant, spindle 10 comprises at least one first upper shoulder 16, housed inside first housing 14 and comprising, at least on its surface, a magnetizable or ferromagnetic material, or an electrostatically conductive material. Said at least one first upper shoulder 16 is subjected, in first housing 14, to the magnetic or electrostatic field generated by first structure 11. Spindle 10 comprises at least one second lower shoulder 17, housed inside a second housing 15, either included in structure 11 or included in third structure 13 of timepiece subassembly 200, forming a stop, in particular a radial stop.

More specifically, the second housing 15 surrounds the second structure 12 comprising one such blocking surface 120 .

More specifically, the spindle 10 is rotatable about a spindle axis AA of the spindle 10 aligned with the pivot axis DA when the spindle 10 is located in the first housing 14. The spindle 10 comprises at least one first cylindrical upper shoulder 16 cooperating with a rotatable orifice forming the first housing 14.

The invention also relates to a movement 500 comprising at least one such timepiece subassembly 200 .

The invention also relates to a watch 1000 comprising at least one such timepiece subassembly 200 .

In a particular embodiment, the structure is made of ceramic and comprises, at least at a surface adjacent to at least one shell 3 , a mosaic arrangement of magnets and/or electrets and/or magnetizable ferromagnetic particles.

In particular, the housing 3 is smooth.

In particular, the structure 1 comprises or forms a ferromagnetic barrier.

If we compare the present invention with prior art embodiments that incorporate magnetic elements in the guide components, it is known from the ETA 2894 movement to use magnets to frictionally brake the small seconds wheel set to eliminate floating: in this case, the magnetic interaction is used solely to dissipate the energy of the wheel set, without ensuring the centering of the rotating wheel set. The anti-seismic configuration according to the present invention differs from this in that:

- the relative position of the magnet and the ferromagnetic part of the rotating wheel set does not change according to the rotation, thus avoiding the torque variation caused by this asymmetry;

- Purely mechanical contact with a minimum contact surface and providing effective friction, thereby minimizing the dissipation of energy and therefore the absorbed torque;

In some variants, the mechanical stop is used only in the event of a shock, whereas the magnetic field ensures the re-centering of the wheel set after the shock, whatever the amplitude of the shock: the mechanical and magnetic forces thus act separately.

Another ETA movement uses magnets to angularly position the time zone system. In this case, the magnetic configuration exerts a limited holding torque (threshold effect) that opposes the angular displacement. The present invention addresses the exact opposite function: the magnetic configuration is limited to exerting radial and/or axial holding/recentering forces without introducing holding or angular braking torques. In this way, the wheel set can rotate freely, but its centering is guaranteed. With reference to Figure 12 , in the case of axial holding, the fundamental feature of the present invention is the cylindrical symmetry of the magnetic system.

The presence of magnetic attraction is one of the characteristic aspects of the present invention, compared to systems incorporating repelling magnets.

For example, in systems that utilize magnetized parts operating solely by magnetic repulsion to generate magnetic levitation, the exact position of the component is therefore not precisely known over time, and the component can—even inevitably—oscillate around its equilibrium position, thereby generating friction at mechanical contacts and causing operational problems if the oscillation amplitude is too high. However, within the scope of the present invention, in most applications, the spindle is pressed against a mechanical stop using magnetic force with a certain prestress. During normal operation, the component is thus in a mechanically fixed, constant position.

The known mechanisms do not utilize the magnetic properties of components whose magnetic parts are merely additional, precisely because arrangements for magnetic attraction are always avoided.

The use of magnetic properties in an anti-vibration function according to the invention represents a departure from known magnetic applications, which are centered by suspension or positioning and in which the positioning is very sensitive to tolerances (geometry of magnets and residual magnetic field).

In practice, dissipating the vibration energy using a magnetic system is not optimal, it is very conservative and requires the use of mechanical stops. In the present invention, re-centering (eg radial re-centering in the case of FIG. 9 ) is a side effect of the (axial) anti-vibration system.

10 and 11 show variants in which the different magnetic fields present are not coaxial and the interaction between the components can in particular be oblique.

By maintaining the mechanical contact through the magnets, the operation of the system according to the invention is rendered insensitive to possible tolerances of the magnets (with regard to positioning).

The main advantage of the magnetic anti-seismic system for spindles is the dependence of the restoring force on the displacement of the spindle, for example, in the axial direction. As with conventional anti-seismic systems, the prestressing force or, in the case of magnetic anti-seismic systems, the contact retention force prevents the component from moving in the event of low vibration levels. Beyond this vibration amplitude, the restoring force of conventional anti-seismic systems increases as the component moves apart due to the spring loading, while the restoring force of the magnetic anti-seismic system according to the present invention decreases as the component moves apart. This feature effectively makes it possible to separate two different systems: a first system in which the vibrations have a low amplitude, and a second system in which the vibrations have a higher amplitude, and when the vibration level value of the higher amplitude is exceeded, the energy is mechanically stored or dissipated, for example by a stop.

In practice, a prestress that varies greatly with tolerances is often observed. By assigning this prestress to the magnetic force, it is possible to rely solely on the mechanical spring for its stiffness during damping above a given vibration amplitude (large vibrations).

The present invention is characterized by various advantages:

- To avoid torque variations due to any asymmetry, the relative positions of the magnets and the ferromagnetic part of the spindle can be designed to be constant with rotation;

- Thanks to magnetic or electrostatic axial retention, purely mechanical contacts can be minimized, especially in configurations using magnetic repulsion and without stops, and where these mechanical contacts are maintained, they have minimal surface contact and provide effective friction, minimizing the dissipation of energy and therefore the absorbed torque.

- These contacts can also be equal to or greater than conventional friction springs and can therefore take advantage of the dissipation of energy to suppress the floating of a pointer or the like;

- in some variants of the invention, the mechanical stop is used only in the event of large shocks, while the magnetic field ensures the re-centering of the spindle after a shock, whatever the amplitude of the shock, and holds the spindle in position during low-level shocks: the mechanical and magnetic forces thus act separately;

The magnetic and/or electrostatic configuration is defined to apply radial and/or axial holding/recentering forces without introducing holding or angular braking torques into the system. In this way, the spindle can rotate freely while ensuring its centering. An advantageous feature of some variants of the invention is the cylindrical symmetry of the magnetic system about the pivot axis DA.

- Lower dependence on tolerances than in the prior art;

- the problems related to wear due to the shocks to which the watch is subjected are significantly reduced, since they only concern the rare instances in which the arbour comes into contact with the mechanical stop in the event of the highest shocks;

- The cooperation between the fields ensures precise re-centering after vibration;

-The highly elastic response of the magnetic field allows for better control of friction;

- the variant presented allows the axial and radial forces to be separated and processed separately;

– Any arbour can later be fixed in the movement using magnetic or electrostatic forces;

- Vibrations of different amplitudes can be handled in different ways by using different components (or parts of components) to dissipate the energy. A certain threshold can be envisaged below which magnetic forces are used and above which the dissipation is mechanical.

The magnetic variant of the timepiece embodiment works correctly with an axial field of 0.55 Tesla.

One specific embodiment involves a steel mandrel with a mass of 60 mg, held in contact by a magnet through magnetic attraction, with an axial field of 0.55 Tesla, a diameter of 0.15 mm (for the portion closest to the magnet), a NeFeB magnet with a remanent field of 1.47 T, and, with a magnet height of 0.8 mm and a radius of 0.45 mm, a sufficient holding force to resist vibrations with accelerations of less than 75 g; this calculation takes into account the presence of a friction layer with a thickness of 60 μm between the mandrel and the magnet. Specifically, in this case, the typical change in magnetic potential energy between the mechanical stop and the operating position contact is 6 μJ for a displacement of 0.1 mm. For a change twice as large (0.12 J/m), two potential energy levels can be generated, for example, for two different vibration regimes (0-100 g and 100-200 g).

For the electrostatic variant and for similar applications, a range between 0.5-50 mC/m ² (fields of approximately 0.01-1 MV/m) should be specified.

The system according to the invention can thus be used to replace mechanical friction springs. Any mechanical friction generated by this system is not necessarily a disadvantage; it can be exploited, including in situations where there is significant friction, to radially hold the sleeve against the spring. Thus, friction can be exploited to dissipate energy from a floating movable element, such as a pointer.

It is also possible to combine the mechanical friction caused by maintaining contact with an eddy current type braking system.

In short, the present invention can separate multiple functions according to the vibration amplitude in the case of vibration:

For systems where the spindle is held against a stop, for example by means of unbalanced magnets, the magnetic force keeps the spindle in contact during low vibrations, but decreases dramatically when the vibrations are large enough to move the spindle apart. The mechanical stop then takes care of things;

For systems in which the magnetization varies in the axial direction, the displacement in this direction is limited to several values, depending on the intensity of the shock, up to a maximum value at which the central axis dissipates the energy remaining on the stop member.

Claims (21)

1. A watch sub-assembly (200) for a wristwatch, comprising a main structure (100) and a spindle (10), the spindle (10) being pivotally movable about a pivot axis (DA) within at least one housing (14; 15) of the main structure (100), the spindle (10) comprising at least one surface (16; 18; 21; 22) made of a magnetized or magnetically conductive material, and the main structure (100) comprising at least one pole shoe (11; 12; 31; 32), the pole shoe being configured to form at least one magnetic field for axial and/or magnetic retention of the spindle (10) adjacent to at least one of the surfaces (16; 18; 21; 22), the watch sub-assembly being characterized in that at least one of the pole shoes (11; 12; 31; 32) forms at least one magnetic field for axial retention and/or magnetic retention of the spindle (10 ... 31; 32) are configured to cooperate with at least one of the surfaces (16; 18; 21; 22) along the pivot axis (DA) in an axial and radial attraction or repulsion manner, so as to keep the mandrel against the housing in the operating position by keeping the mandrel in contact with the position stop or with the permanent magnet, thereby allowing the mandrel to travel a certain distance during vibration to absorb radial vibration and return the mandrel (10) to the operating position after the vibration stops; and at least one of the pole shoes (11; 12; 31; 32) is configured to form at least one of the magnetic fields adjacent to at least one of the surfaces (16; 18; 21; 22), the magnetic field tending to radially attract the mandrel (10) toward the wall of the housing (14; 15). 2. The watch subassembly (200) according to claim 1, characterized in that at least one of the magnetic fields ensures axial attraction or repulsion of the spindle (10) and is substantially rotational about the pivot axis (DA); at least one of the magnetic fields has an intensity greater than 0.55 Tesla in the axial component along the pivot axis (DA). 3. The watch sub-assembly (200) according to claim 1, characterized in that the spindle (10) is only axially braked by magnetic potential energy along the pivot axis (DA), the magnetic potential energy varying along the pivot axis (DA), and forming a resisting force resulting from the cooperation of attraction or repulsion between at least one of the pole shoes (11; 12; 31; 32) and at least one of the surfaces (16; 18; 21; 22). 4. The clock sub-assembly (200) according to claim 3, characterized in that the potential energy curve is such that the resisting force continuously increases or decreases as the spindle (10) travels along the pivot axis (DA). 5. The watch sub-assembly (200) according to claim 3, characterized in that the spindle (10) is axially braked along the pivot axis (DA) by the curve of the potential energy forming at least one magnetic field barrier, the barrier forming a virtual annular pawl configured to brake or stop the travel of the spindle along the pivot axis (DA). 6. The clock sub-assembly (200) according to claim 5, characterized in that the spindle (10) is axially braked only by the plurality of barriers along the pivot axis (DA), and absorbing a portion of the kinetic energy of the vibration when crossing each barrier, each barrier forming the boundary of a potential energy level. 7. The watch sub-assembly (200) according to claim 5, characterized in that the barriers are successive and have an increased magnetic field strength along the pivot axis (DA) from the operating position of the spindle (10) toward the mechanical stop included in the main structure (100). 8. The watch sub-assembly (200) according to claim 7, wherein the mechanical stop and the magnetic stop are paired, or the mechanical stop forms a magnetic stop. 9. The watch sub-assembly (200) according to claim 1, characterized in that the main structure (100) includes a first structure (11), the first structure (11) including at least one first housing (14), the spindle (10) being pivotally movable at least inside the first housing, the first structure (11) forming at least one of the magnetic fields in the first housing (14) substantially rotating about the pivot axis (DA) to subject the spindle (10) to a force tending to center the spindle (10) along the pivot axis (DA); and the main structure (100) includes a magnetized blocking surface (120) in a second housing (15) disposed on the first structure (11) or on a second structure (12) included in the main structure (100), the blocking surface (120) being configured to axially attract or repel the magnetized front surface (18) included in the spindle (10) along the pivot axis (DA). 10. The clock sub-assembly (200) according to claim 9, wherein at least one of the magnetic fields has an intensity greater than 0.55 Tesla between the front surface (18) and the blocking surface (120). 11. The watch subassembly (200) according to claim 9, characterized in that the spindle (10) includes at least one first upper shoulder (16), the first upper shoulder being housed inside the first housing (14), and including at least one magnetizing or magnetically conductive material on the surface of the first upper shoulder, the first upper shoulder (16) being subjected to at least one of the magnetic fields generated by the first structure (11) inside the first housing (14); and the spindle (10) includes at least one second lower shoulder (17), the second lower shoulder being housed inside a second housing (15) included in the first structure (11) or in the third structure (13) of the watch subassembly (200), the second housing (15) forming a stop. 12. The clock sub-assembly (200) according to claim 11, characterized in that the second housing (15) surrounds the second structure (12) including the blocking surface (120). 13. The watch subassembly (200) according to claim 9, characterized in that, when the spindle (10) is located inside the first housing (14), the spindle (10) is rotatable about the spindle axis (AA) of the spindle (10) aligned with the pivot axis (DA); and the spindle (10) includes at least one first cylindrical upper shoulder (16) that cooperates with a rotation aperture forming the first housing (14). 14. The clock sub-assembly (200) according to claim 1, characterized in that the magnetic field generates magnetic force, which applies force to the spindle in three directions by keeping the spindle in contact inside the triangle, wherein the triangle positions the spindle on the position stop or directly on the permanent magnet. 15. The watch subassembly (200) according to claim 1, characterized in that the watch subassembly includes a radial mechanical guiding system for the spindle and a magnet for ensuring axial retention, and the magnetic force generated by the magnetic field is used to apply force to the spindle in one or two of the three directions, while the radial mechanical guiding system is used to restrict the movement of the spindle in the other directions. 16. The watch subassembly (200) according to claim 15, wherein the radial mechanical guiding system is realized by a sleeve in an aperture of the first structure, and the spindle is axially held by a magnet included in the second structure. 17. The watch subassembly (200) according to claim 1, characterized in that the magnetic force generated by the magnetic field applies force to the spindle in three directions by holding the spindle in a concave trihedron in contact, the concave trihedron positioning the spindle and also forming a set of position stops; and the watch subassembly includes a magnetic element that retracts relative to the contact surface, or the surface of the magnetic element is the contact surface. 18. The watch subassembly (200) according to claim 1, wherein the magnetic field generates magnetic force; and the watch subassembly includes a safety stop for limiting excessive displacement, and a potential contact area is configured to limit the travel of the spindle when the magnetic force is too low to resist vibration. 19. The watch subassembly (200) according to claim 1, wherein at least a portion of the at least one pole shoe is stacked with the spindle in a radial direction perpendicular to the pivot axis. 20. A movement (500) comprising at least one watch sub-assembly (200) according to claim 1. 21. A watch (1000) comprising at least one watch sub-component (200) according to claim 1.