Watch with electromechanical generator

Abstract

The invention relates to a watch comprising a movement (44a) located within a case (6b) and an electromechanical generator (88) comprising a stator and a rotor (92), one of which carries a permanent magnet (18a, 18b) and the other carries a coil (14). The rotor has an annular structure and is guided in rotation by at least one ball bearing (100a), the rotor has a free inner space (130) over its entire height, the geometric axis of rotation of the rotor passes through the space, and the movement is located at least partially within the space. In one main embodiment, the watch includes a barrel that constitutes a rotor drive activated according to instructions. In one major variant, the watch includes a lighting device (64) powered by a coil. In one advantageous variant, the rotor carries coils, which are connected via an electrical circuit without an electrical storage device to a lighting device fixedly arranged on the rotor.

Description

TECHNICAL FIELD

[0001] The present invention relates to a watch incorporating an organic electro-generator. In particular, the present invention relates to a watch equipped with a mechanical movement, i.e. the driving means of the analog time display means of the watch are entirely mechanical and the barrel serves as an energy source.

[0002] In particular, the present invention relates to a watch equipped with lighting means for displaying a space, in which an analog display means is provided, the lighting means being powered by an electro-mechanical generator. BACKGROUND

[0003] Mechanical watches equipped with various additional lighting systems are already present on the market. In one particular embodiment disclosed in document EP3838424, the lighting means are powered by a micro-generator, also called "electric generator", which is driven in rotation by the mainspring of the barrel and which acts as a speed regulator of the time indication means. The coil on the micro-generator is carried by its stator, while the rotor generally carries permanent magnets.

[0004] As regards the micro-generator, it should be noted that the generator and the corresponding electrical and electronic circuitry are entirely located inside the watch movement, occupying a relatively large space inside the movement. If the watch movement is to be displayed through a glass in the rear cover of the case, at least the generator is clearly visible. This gives the watch movement an electro-mechanical hybrid appearance which is particularly unsuitable for high-end watches, the value of which lies mainly in the mechanical watch movement. Moreover, the large amount of space occupied by the generator in the movement increases the bulk of the movement. In addition, the height of the generator is also high, since the rotor comprises a plurality of magnets on at least one disc, which are stacked axially on the coil in the stator, and a central arbor carrying said at least one disc, the two ends of which pivot in the supports of the movement, for example in the movement plate and the clamping plate of the generator.

[0005] It should also be noted that the above-mentioned lighting system presents some drawbacks for a watch equipped with a mechanical movement, in particular a high-end watch, for which it is essential to preserve the purely mechanical nature of the movement as much as possible. This lighting system in fact comprises at least one electroluminescent element, for example at least one LED, an electrical circuit, an electronic circuit and at least one electrical energy storage device, which are arranged on the supports in the watch movement, at the periphery of the rotor of the micro-generator, thereby introducing electronic-type devices and electrical energy storage devices into the watch movement. SUMMARY

[0006] The primary object of the present invention is to provide a watch equipped with an electro-mechanical generator which can solve the various problems mentioned above in the case of integration of a micro-generator, hereinafter called "electro-mechanical generator" or simply "generator", in the watch movement.

[0007] It is therefore an object of the present application to provide a watch equipped with a mechanical-electrical generator and a lighting device, and to provide a solution to the various drawbacks mentioned above in relation to lighting systems.

[0008] It is another object of the present application to provide a lighting device for the display means of an analog watch, in particular the hands and the dial, which is elegant, compact and suitable for high-end watches, and which does not require the installation of special optical devices in the elements of the analog display means themselves, in particular the dial.

[0009] To this end, the present application first relates to a watch comprising a movement, a mechanical-electrical generator, and a watch case housing the movement and the mechanical-electrical generator, the generator comprising a stator and a rotor, one of the stator and the rotor carrying permanent magnets and the other carrying coils. The permanent magnets and the coils are arranged so that when the rotor rotates, the permanent magnets move in a reference frame associated with the coils, successively opposite each coil, and the respective magnetic axis of the permanent magnets passes through the coils. The rotor has an annular structure and is guided in rotation by at least one ball bearing, the rotor having a free internal space over its entire height, the geometric axis of rotation of the rotor passing through this space, and the movement being at least partially located in this space.

[0010] According to an advantageous variant, the rotor on the mechanical-electrical generator is substantially entirely, preferably entirely, located within the peripheral space of the movement. By "entirely located within the peripheral space", it is meant that the movement is contained within a geometric volume which extends internally along the outer lateral surface of the movement, and that the rotor does not protrude into this volume, except possibly the internal toothing of the rotor which engages the wheels of the mechanical drive means on the generator, in the case where the mechanical drive means are contained in the movement. It should be noted that, in a particular embodiment which will not be described, the mechanical drive means of the rotor can be independent of the movement and located outside the volume of the movement in the watch case. According to a preferred variant, the stator on the mechanical-electrical generator is substantially entirely, preferably entirely, located within the peripheral space of the movement. By "substantially entirely located within the peripheral space" for the stator, it is meant in this case that the coils are substantially located outside the volume of the movement, but that a portion of the coil support can optionally protrude into this volume, in particular in order to fix the coil support to the movement.

[0011] In an advantageous variant, the axial dimension of the mechanical-electrical generator is less than the axial dimension of the movement.

[0012] In an advantageous embodiment, the watch includes a plurality of ball bearings with a diameter smaller than the inner radius of the rotor, preferably less than half of that inner radius. Each of the plurality of ball bearings includes a fixed portion and a movable portion that moves between the fixed portion and the rotor. Each movable portion and the rotor are configured such that the rotor is supported only by the plurality of movable portions of the plurality of ball bearings and is rotatable about the geometric axis of rotation of the rotor.

[0013] In the first main embodiment, the rotor includes an imbalance portion, allowing the rotor to be actuated by the movement of the watch user and rotate freely; and the coil is connected to the energy storage device via a rectifier.

[0014] In a second main embodiment, the watch includes a mechanical drive for a rotor, the mechanical drive including a mainspring barrel, and arranged such that the mechanical drive can be activated according to a command from the watch user.

[0015] In an advantageous embodiment, the watch includes a lighting device powered by coils. In a preferred variant of this embodiment, a rotor carries coils that are connected directly or via electrical circuitry (and, if necessary, electronic circuitry) without a power storage device to the lighting device, which is fixedly arranged on the rotor. Attached Figure Description

[0016] The invention will now be described in more detail with reference to the accompanying drawings, which are given by way of non-limiting example, wherein:

[0017] - Figure 1 This is a partial cross-sectional view of a watch according to a first main embodiment of the present invention;

[0018] - Figure 2 This is a partial cross-sectional view of a watch according to a second main embodiment of the present invention;

[0019] - Figure 3 The watch edge is according to an advantageous embodiment Figure 4 and Figure 5 The horizontal cross-sectional view along line III-III shows that the watch uses an electromechanical generator as the energy source for the lighting device in the display space of the watch.

[0020] - Figure 4 It is along Figure 3 A partial cross-sectional view of section IV-IV of the watch; and

[0021] - Figure 5 It is along Figure 3 A partial cross-sectional view of the VV section line of the watch. Detailed Implementation

[0022] A first main embodiment of a watch according to the application will be described below with reference to the accompanying drawings, in which: Figure 1 A first main embodiment of a watch according to the application will be described below with reference to the accompanying drawings, in which:

[0023] The watch 2 comprises a movement 4, an electromechanical generator 8, and a case 6 which houses the movement and the electromechanical generator. The generator 8 comprises a stator 10 carrying coils 14 and a rotor 12 carrying permanent magnets 18a, 18b. In general terms, the permanent magnets and the coils are arranged so that, when the rotor rotates, the magnets successively move in a reference frame associated / fixed with the coils and at least partially opposite each coil, at which time the respective magnetic axis of these magnets (represented by arrows in the figures) passes through the coil. According to the application, the rotor 12 has an annular structure and is guided in rotation by at least one ball bearing 20. In addition, the rotor has a free internal space 24 over its entire height, the geometric axis of rotation of the rotor (similar to the axis 34 shown in Figure 2 The watch 2 comprises a movement 4, an electromechanical generator 8, and a case 6 which houses the movement and the electromechanical generator. The generator 8 comprises a stator 10 carrying coils 14 and a rotor 12 carrying permanent magnets 18a, 18b. In general terms, the permanent magnets and the coils are arranged so that, when the rotor rotates, the magnets successively move in a reference frame associated / fixed with the coils and at least partially opposite each coil, at which time the respective magnetic axis of these magnets (represented by arrows in the figures) passes through the coil. According to the application, the rotor 12 has an annular structure and is guided in rotation by at least one ball bearing 20. In addition, the rotor has a free internal space 24 over its entire height, the geometric axis of rotation of the rotor (similar to the axis 34 shown in

[0024] In the first main embodiment shown in Figure 1 In this advantageous variant of the first main embodiment shown in, the rotor 12 has a ferromagnetic structure, in this case formed as two annular portions 17a and 17b, the cross section of which as a whole is C-shaped (or more precisely, U-shaped with straight portions). More specifically, the portion 17a is L-shaped and carries a first set of permanent magnets 18a located above the coils 14; the portion 17b is straight and carries a second set of permanent magnets 18b located below the coils 14. Thus, the coils 14 are advantageously located between pairs of magnets of the same polarity and axially aligned, the magnetic axes of the magnets also being axial. In order to limit the thickness of the generator and to easily make each pair of magnets equidistant from the coils, the coils are located in the openings of the support 15, which is optionally formed as a PCB on which the coils are fixed. The coils 14 and the pairs of magnets 18a, 18b are arranged in a circular arrangement, with the axis of rotation of the rotor as the central axis. In the first variant, the number of magnets in each set of magnets is equal to the number of coils, which is advantageously preselected between 24 and 48, but is not limited thereto. In this case, all the magnets have the same polarity (the same direction of polarization). In the second variant, the number of magnets in each set of magnets of the generator is twice the number of coils, and thus the number of pairs of magnets is also twice the number of coils. In the latter case, the magnets in each set of magnets or pair of magnets have alternating polarity.

[0025] In the variant shown in Figure 1 In this variant, a single ball bearing 20 is provided, which consists of a fixed annular portion 21 and a movable annular portion 22, between which the balls 23 are located. In this variant, the movable annular portion 22 forms part of the rotor 12. In the first variant, Figure 1In the variant shown, the fixed portion 21 of the ball bearing 20 is located outside the rotor 12 and is fixed to the case 6. The rotor on the electromechanical generator 8 is entirely located within the peripheral space of the movement 4, which is advantageous because it does not obstruct the movement, and this design makes it possible for the rotor and the stator coil to be located outside the cylindrical space extending axially from the lower table mirror of the case 6. According to the variant considered, only the support 15 of the coil 14 can partially extend into this cylindrical space. By "peripheral space", we mean a space that laterally surrounds the geometric volume defined by the movement 4, i.e. by the entire outer surface of the movement 4.

[0026] To install the generator 8 in the case 6 of the watch 2, it is first necessary to insert the ball bearing 20, together with the rotor upper portion 17a carrying the upper magnet 18a, into the case from the rear side of the case, through a lower opening in the intermediate piece (the rear cover needs to be removed in order to install the generator and the movement), and to assemble the fixed annular portion 21 to the case 6. It should be noted that the upper portion 17a has been previously fixed to the movable annular portion 22 of the ball bearing. Then, the movement 4 and the stator 10 (optionally together with the dial) are also inserted into the case through said lower opening, and the movement is fixed in the case. It should be noted that the stator can be previously fixed to the movement or after installation in the case 6. In one variant not shown, the stator is fixed to the fitting circle 4 of the movement. Finally, the magnet 18b is added to the rotor lower portion 17b, and this lower portion 17b is fixed to the upper portion 17a to form the rotor 12 and the magnetic circuit connecting the magnet 18a and the magnet 18b. The two portions are fixed with screws 26 screwed into threaded tubes attached to the movable portion 22 and to the rotor upper portion 17a. It should be noted that the lower portion 17b extends radially beyond the upper portion 17a to ensure that the two portions are rigidly and stably fixed.

[0027] The first main embodiment relates to a watch in which the electromechanical generator 8 is the source of electrical energy for converting the mechanical energy produced by the user's arm movements into electrical energy stored in the watch in order to subsequently power at least one electrical and / or electronic device or system carried by the watch. To this end, the rotor 12 carries an unbalance 28. Since this unbalance is fixed to the rotor and rotates with the rotor, the rotor can also be said to comprise the unbalance 28. For example, the unbalance extends over an angular distance of 180°. In this way, the unbalance enables the rotor 12 to be actuated in rotation by the movements of the user of the watch. In order to store the electrical energy produced by the generator 8, the coil 14 is connected to an electrical storage device 32 via a rectifier 30. In the variant shown, these electrical elements 30 and 32 are arranged on the support 15 of the stator 10, which forms a PCB via which the coils, advantageously arranged in series, are connected to the rectifier, which rectifies the sinusoidal electrical signal supplied by the generator in order to store the electrical energy in the electrical storage device 32, in particular a rechargeable battery.

[0028] It should be noted that the PCB 15 partly projects into the movement 4. This means that the electromechanical generator is almost entirely located in the peripheral space of the movement. In a first variant, the PCB constituting the stator 10 and carrying the electrical elements is entirely located at the periphery of the movement, it being fixed to the movement or to the case or to the bezel. In a second variant, the two ends of the coils connected in series are connected to two electrode pads on a PCB on which the electrical elements 30 and 32 are arranged, via two wires or via a flexible connector or via other types of electrical connectors, the PCB being independent of the support constituting the stator 10, which is entirely located at the periphery of the movement 4. In the first variant and in the second variant, the stator and therefore the generator are entirely located in the peripheral space of the movement, the movement and the generator being mutually separated, the generator being peripheral to the movement, the movement being located inside the generator.

[0029] A second main embodiment of a watch according to the application will be described below with reference to Figure 2 A second main embodiment of a watch according to the application will be described below with reference to

[0030] The watch 42 according to the second main embodiment of the application differs from the first main embodiment mainly in that the rotor 52 on the electromechanical generator 48 is driven according to command from the barrel 72 on the movement 44 via a gear train, which is constituted by the wheels 74, 75, the barrel storing mechanical energy by manual winding or by automatic winding via the balance, and is dedicated to the lighting device of the watch, the source of electrical energy being the generator 48. Overall, the watch comprises a mechanical drive of the rotor comprising a barrel and arranged so that it can be activated according to the command of the user of the watch in order to drive the rotor on the generator in order to produce electrical energy.

[0031] The generator 48 comprises a stator 50 and a rotor 52, the rotor carrying the permanent magnets 18 and the stator carrying the coils 14. The permanent magnets and the coils are arranged such that when the rotor rotates, the permanent magnets move in a reference frame associated / fixed with the coils and successively at least partially oppose each coil, at which time the respective magnetic axis of these permanent magnets passes through the coil. According to the invention, the rotor 52 has an annular structure and is guided in rotation by a ball bearing 60. The rotor 52 has a free inner space throughout its height, the geometrical axis of rotation 34 of the rotor passing through this space and the movement 44 being partly located in this space. The rotor 52 on the electromechanical generator is entirely located in the peripheral space of the movement. In the advantageous variant shown, the stator 50 on the electromechanical generator 48 is also entirely located in the peripheral space of the movement 44. Furthermore, the axial dimension of the electromechanical generator 48 is less than the axial dimension of the movement 44. Integrating the generator 48 into the watch 42 does not increase the thickness of the watch. Furthermore, the generator can be easily installed in the case 6a and the space above the movement 44 is not obscured by the generator. The latter property is particularly useful for the watch 42 since the watch 42 contains means for illuminating the display space 70 from the periphery of the display space 70, the display space 70 being located between the dial 68 and the upper watch glass 78 (this illumination means will be described in more detail below).

[0032] The ball bearing 60 is constituted by a fixed part 21a and a movable part 22a, the balls 23 being located between the fixed part 21a and the movable part 22a, the movable part 22a being annular and forming part of, or in other words being attached to, the rotor 52. The variant shown is characterized in that the fixed part 21a of the ball bearing 60 is located on the inside of the rotor 52 and is fixed on the movement 44. In particular, the fixed part 21a is formed annularly, it surrounds the movement 44, for example in the middle region of the movement 44, as shown in the figures, or in the periphery of the movement 44, as shown in the figures. Figure 2Only the wheel 75 on the rotor drive moves under the ball bearing 60 and engages with the internal toothing machined on the inner lateral edge of the ferromagnetic ring 58, which constitutes the rotor 52 and carries the bipolar permanent magnets 18. The ferromagnetic ring 58 is attached to the movable part 22a of the ball bearing 60 and, together with the ferromagnetic annular portion 56 of the stator 50, forms the magnetic circuit for closing the magnetic field generated by the magnets 18, so that the magnetic field passes through the coils 14 in the best way. The annular portion 56 of the stator has an L-shaped cross section and is fixed to the case 6a. The annular portion 56 carries the annular PCB 54 arranged below its horizontal portion, below which the coils 14 are arranged, facing the magnets 18. As a non-limiting example, the PCB 54 carries 20 to 40 coils, uniformly distributed around the rotation axis 34. The rotor 52 carries the same number of magnets with the same polarity, or twice the number of magnets with alternating polarity, uniformly distributed on the ferromagnetic ring 58. The generator 48 differs from the generator 8 in the first embodiment mainly in that the rotor 52 carries a single set of magnets arranged in the same geometric plane perpendicular to the rotation axis 34, so that these magnets are all located on the same side of the coils 14.

[0033] Secondly, the second main embodiment differs from the first main embodiment in that the lighting device on the watch is powered in real time by the generator 48 (more precisely, by the coils 14 on the generator 48 when the rotor 52 rotates at a speed higher than a given minimum value), directly or by means of an electrical and / or electronic circuit without an electric storage device, which optionally has at least one smoothing capacitor made of solid material (such a smoothing capacitor does not belong to the electric storage device, since it does not store energy). This electrical and / or electronic circuit can in particular comprise a Greinacher rectifier bridge.

[0034] In the illustrated variant, the lighting device consists of a plurality of electroluminescent diodes 64 (LEDs 64) and a ring-shaped light guide structure 66 forming the flange on the watch. The stator 50 carries coils which are connected, directly or via electrical circuits (and, if necessary, electronic circuits) without electrical storage device, to said plurality of electroluminescent diodes 64 arranged in parallel. The lighting device is preferably arranged on the stator, the ring-shaped PCB 54 carrying the coils 14 on one side and the LEDs 64 on the other side. The PCB also carries various electrical connections and any planned electrical and / or electronic circuits. As a non-limiting example, 6 to 18 LEDs are foreseen, uniformly distributed at an angle. It should be noted that these LEDs are located in the through-holes of the ferromagnetic ring-shaped portion 56, facing the ring-shaped light guide structure 66. The ring-shaped light guide structure 66 has an entry surface for the light produced by the LEDs, located above the LEDs, and a cylindrical surface for extracting said light, which defines a display space 70 and allows the light to exit the light guide into this display space.

[0035] In this second embodiment, the movement 44 can advantageously be of the mechanical type (not containing electrical or electronic elements). All the electrical and electronic elements contained in the watch are arranged at the periphery of the mechanical movement 44, in particular the electric generator 48 and the lighting device 64 for the display space 70. The lower watch glass 76 does not expose any electrical or electronic element, not even any permanent magnet in the electric generator (it should be noted that, in the watchmaking field, an integrated permanent magnet is considered as a non-electrical / electronic element). In the first variant, the ball bearing 60 is fixed on a mounting ring on the mechanical movement 44. In the second variant, as in the variant in the first embodiment, the ball bearing is arranged on the outside of the rotor and is fixed on the watch case 6a.

[0036] The application will be described below with reference to Figures 3 to 5 One advantageous embodiment of the application is described for a watch comprising a display space lighting device, powered by an electromechanical electric generator. The various features of the application already described above will not be repeated and the unique aspects of this advantageous embodiment will first be introduced.

[0037] The watch 82 comprises a watch case 6b in which a movement 44a Figure 3The electric generator 88 comprises a stator 90 and a rotor 92 having an annular structure and, according to a first main feature of this advantageous embodiment, the rotor 92 is guided in rotation by at least two ball bearings, preferably at least three ball bearings 100a, 100b, 100c. Overall, the watch 82 contains a plurality of ball bearings having a diameter smaller than the inner radius R of the rotor, preferably smaller than half of this inner radius. Each ball bearing of said plurality comprises a fixed part 101 and a movable part 102, the movable part 102 being mobile between the fixed part and the rotor 92, each movable part and the rotor being configured so that the rotor is only supported by a plurality of movable parts of said plurality of ball bearings and is able to rotate around a central geometric axis 34 of the rotor, i.e. the rotation axis of the rotor. Each bearing generally contains a ball 103 between its fixed part and its movable part. The particularity of this example compared to the previous embodiments is that the movable parts of the ball bearings are not attached to the peripheral annular rotor 92 and thus do not belong to this rotor. The movable parts roll along a track 97 machined in the inner portion 96 of the rotor, laterally.

[0038] For example, the track 97 has a cross-sectional profile defining three straight sections, the dimensions of which are designed so that each movable part 102 has a small clearance in the groove forming said track and, according to the spatial orientation of the watch, is in contact at one or two points along said profile. Preferably, in this advantageous embodiment, each ball bearing is located on the inside of the rotor and each fixed part is mounted in the movement 44a. In one variant, the fixed part 101 is mounted on a mounting ring on the movement. The rotor 92 has an inner toothing 98 which meshes with the wheel 75 of the transmission (wheels 74 and 75) arranged between the barrel 72 and the rotor. The drive mechanism on the electric generator is designed so that it can drive the electric generator in a controlled manner according to the instructions, in particular so that the angular speed of rotation of the electric generator is higher than the minimum speed required for the lighting device to work normally (depending on the arrangement of the electric generator 88), as soon as the barrel is wound above a lower threshold.

[0039] As with the other embodiments, the rotor 92 has a free internal space 130 throughout its height, through which passes the geometric axis of rotation 34 of the rotor, and in which the movement 44a is partly located. The rotor 92 in turn is substantially entirely located in the peripheral space of the movement. In fact, in the variant shown, only three ball bearings, which are associated with the rotor and support it to allow it to rotate freely, and the drive wheel 75, which meshes with the internal toothing 98 of the rotor, are in contact with the rotor 92, which are located on the inner side of the rotor. It can thus be said that, in the variant shown, the rotor is entirely located in the peripheral space of the movement 44a. Furthermore, the stator 90 on the generator is also substantially entirely located in the peripheral space of the movement. In fact, although the recesses 110 and 120 in the stator are not considered part of the stator bulk, it can be said that the stator 90 is also entirely located in the peripheral space of the movement. Thus, the electro-mechanical generator is substantially entirely, preferably entirely, arranged within the peripheral space of the watch movement. Thus, in the variant shown, the movement is substantially entirely inside the generator 88, in the internal volume of the generator defined by the stator 90, in fact, according to the description above and the height of the generator in the variant shown, the movement is entirely located in the internal volume.

[0040] According to a second main feature of the advantageous embodiments described herein, the rotor 92 advantageously carries the coil 14, which is connected, directly or via an electrical circuit (and, if necessary, an electronic circuit) without storage means, to the lighting device, which consists of a plurality of electroluminescent diodes 64 (LEDs 64) fixedly arranged on the rotor. More specifically, the rotor comprises an annular support 94, which forms a rigid PCB ("printed circuit board") having circular openings in which the coil 14 is located and which is fixed to the annular support 94, while the annular support 94 itself is carried by the internal portion 96 of the rotor. The LEDs, the various electrical connections that make up the circuit, and, if appropriate, any electronic circuit in addition to the LEDs, are arranged on and carried by the PCB. Thus, the rotor carries all the electrical and electronic equipment comprising the plurality of electroluminescent diodes, the coil of the generator 88, the electrical interconnection circuit, and, if necessary, any other electrical or electronic components associated with the lighting device and the electro-mechanical generator that powers the lighting device.

[0041] The stator 90 comprises a first set of axially magnetized bipolar permanent magnets 18a, carried at the bottom by a first portion 106a of an annular ferromagnetic structure forming a magnetic circuit for closing the magnetic field of the first set of permanent magnets 18a and a second set of permanent magnets 18b, carried at the top by a second portion 106b of the annular ferromagnetic structure, which in this case is fixed in the embodiment described, unlike the variant in the first main embodiment described previously, in which the rotor comprises a similar annular structure carrying the two sets of magnets. The annular structure comprises recesses 110 for the ball bearings 100a, 110b and 110c, and a recess 120 for the drive wheel 75. These recesses are machined in the lateral walls (axial / vertical walls) and, optionally, as shown, also in the second portion 106b (lower part on the back side of the case), in order to facilitate the assembly of the ball bearings and the drive wheel 75.

[0042] In Figure 3 In the first variant shown, the number of magnets in each set of magnets is equal to the number of coils, which in the variant shown is 36. Advantageously and non-limitingly, this number is preset between 20 and 40. In a second variant, the number of magnets per set of magnets of the electromechanical generator is twice the number of coils, with each set of magnets having an alternating polarity.

[0043] The lighting device is combined with a light guide structure 66a, similar to the case described in the second embodiment. This light guide structure is arranged to conduct the light produced by the lighting device, i.e. the LEDs 64, to a display space 70 provided with an analog display device (not shown) of the watch inside the display space 70, which is located between the dial 68 and the upper watch glass 78. According to Figure 4 and Figure 5 According to one preferred variant shown, the light guide structure forms a flange around the display space 70 on the watch. The light guide structure has a lower annular surface defining the entry surface of the light produced by the LEDs and a cylindrical surface laterally delimiting the display space 70 and the light extraction surface. The cross-sectional profile of the light guide structure, in particular the rear portion, can be optimized to efficiently guide the light to the extraction surface. The surfaces of the light guide structure, in particular the rear surface, can be treated or coated with one or more layers of coating, in particular a reflective layer. In the variant embodiment described here, given that the light guide structure forms a flange and is thus located in the portion of the periphery of the dial 68, it is advantageous for the LEDs 64 to be located outside the coils 14.

[0044] The advantageous embodiment described herein has a significant advantage in terms of lighting of the display space 70 compared to the variants in the second main embodiment described above. This significant advantage stems from the fact that the LEDs are arranged on the rotor and therefore rotate with it. In this way, the cylindrical surface of the structure 66a that defines the flange is swept by the light rays generated by each LED in a tangential direction perpendicular to the rotation axis 34, or in other words, in an angular direction. If the number of LEDs is sufficiently high (for example, 12 as shown in Figure 3 the user's eye perceives almost uniform and almost stationary lighting of the display space, since the lighting is generated only when the generator is started and the rotor is rotating, and the electrical energy generated is instantaneously supplied to the LEDs 64. In the second embodiment, the LEDs are arranged on the stator and remain stationary when energized (rotor rotating) and therefore it is difficult or even impossible to generate angularly uniform lighting on the cylindrical surface of the flange. In the latter case, especially with 12 LEDs, it is possible to enhance the lighting for the area of the dial that, for example, includes the marks or numbers indicating the hours.

[0045] In a first variant, instead of the light guide structure 66a, a blank space can be left above the LEDs, delimited by a reflecting surface configured to optimally reflect the light rays towards the display space 70, in particular the dial 68. The display space is advantageously enclosed by a cylindrical portion that is at least partially transparent to the light rays generated by the LEDs at least in a radial direction towards the display space and therefore towards the central rotation axis 34, through which the light rays generated by the LEDs and reflected by the reflecting surface pass. The reflecting surface can be defined by the inner surface of the case or by a specific component inserted into the case.

[0046] In a second variant, a light guide structure is provided that is transparent to the light generated by the LEDs, having a light extraction surface arranged behind a cylindrical flange that forms a cylindrical wall that defines the display space, the cylindrical flange being at least partially transparent to the light rays of the LEDs incident on it towards the display space.

[0047] Finally, in another embodiment of the watch with a generator according to the present application, the rotor is likewise supported by a plurality of ball bearings of the type described above in the advantageous embodiment, with each ball bearing being located on the outer side of the rotor and each fixed portion being fixed to the case.

Claims

1. A watch (2, 42, 82) comprising a movement (4, 44), an electromechanical generator (8, 48, 88), and a case (6, 6a, 6b) housing the movement and the electromechanical generator, the electromechanical generator comprising a stator (10, 50, 90) and a rotor (12, 52, 92), one of the stator and the rotor carrying a permanent magnet (18, 18a, 18b), and the other carrying a coil (14), the permanent magnet and the coil being arranged such that, as the rotor rotates, the permanent magnet moves in a reference frame associated with the coil, successively at least partially opposite each coil, and the magnetic axis of each permanent magnet passes through the coil; characterized in that, The rotor has an annular structure and is guided to rotate by at least one ball bearing (20; 60; 100a, 100b, 100c). The rotor has a free internal space (24, 130) over its entire height. The geometric axis of rotation (34) of the rotor passes through the free internal space, and the movement is at least partially located in the free internal space.

2. The watch according to claim 1, characterized in that, The rotors (12, 52, 92) on the electromechanical generator are substantially and preferably completely located in the peripheral space of the core (4, 44).

3. The watch according to claim 2, characterized in that, The stator (50, 90) on the electromechanical generator is substantially completely, preferably completely, located in the peripheral space of the mechanism (44).

4. The watch according to any one of the preceding claims, characterized in that, The axial dimension of the electromechanical generator (48) is smaller than the axial dimension of the mechanism.

5. The watch according to any one of the preceding claims, characterized in that, The ball bearing (20, 60) consists of a fixed part (21, 21a) and a movable part (22, 22a), with balls (23) located between the fixed part and the movable part. The movable part is annular and forms part of or is attached to the rotor.

6. The watch according to claim 5, characterized in that, The fixed part (21) of the ball bearing (20) is located on the outside of the rotor (12) and fixed to the case (6).

7. The watch according to claim 5, characterized in that, The fixed portion (21a) of the ball bearing (60) is located inside the rotor (52) and fixed to the mechanism (44).

8. The watch according to any one of claims 1 to 4, characterized in that, The watch (82) includes a plurality of ball bearings (100a, 100b, 100c), the diameter of which is smaller than the inner radius (R) of the rotor (92), preferably less than half of the inner radius; and each of the plurality of ball bearings includes a fixed portion (101) and a movable portion (102), the movable portion being movable between the fixed portion and the rotor, each of the movable portion and the rotor being configured such that the rotor is supported only by the plurality of movable portions of the plurality of ball bearings and is rotatable about the geometric axis of rotation.

9. The watch according to claim 8, characterized in that, Each ball bearing (100a, 100b, 100c) is located inside the rotor, and each fixed part is fixed to the movement.

10. The watch according to claim 8, characterized in that, Each ball bearing is located on the outside of the rotor, and each fixed part is fixed to the case.

11. The watch according to any one of the preceding claims, characterized in that, The rotor (12) includes an unbalanced portion (28) or is attached to the unbalanced portion, thereby allowing the rotor to be actuated by the movement of the watch user and rotate freely; and the coil (14) is connected to the energy storage device (32) via a rectifier (30).

12. The watch according to any one of claims 1 to 10, characterized in that, The watch includes a mechanical drive mechanism (72, 74, 75) for a rotor, the mechanical drive mechanism including a mainspring barrel (72) and arranged to be activated according to a command from the watch user.

13. The watch according to claim 12, characterized in that, The watch includes a lighting device (64) powered by a coil.

14. The watch according to claim 13, characterized in that, The stator (50) carries the coil (14), which is connected to the lighting device directly or via an electrical circuit without a storage device.

15. The watch according to claim 14, characterized in that, The lighting device (64) is fixedly arranged on the stator.

16. The watch according to claim 13, characterized in that, The rotor (92) carries the coil (14), which is connected directly or via an electrical circuit without a storage device to the lighting device (64), wherein the lighting device (64) is fixedly arranged on the rotor.

17. The watch according to any one of claims 13 to 16, characterized in that, The lighting device includes or is connected to at least one light guide structure (66, 66a) arranged to conduct light generated by the lighting device (64) to a display space (70) in which an analog watch display device is located.

18. The watch according to claim 17, characterized in that, The light guide structure (66, 66a) forms a flange around the display space (70) on the watch, or has a light extraction surface arranged behind at least partially transparent flange, which is capable of transmitting incident light toward the display space.

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