• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a bearing (100) for a timepiece, produced in a single block in a substrate transparent to the wavelength of a laser, and comprising a central part (106) delimiting a hole (107) intended guiding a pivot (21), the hole (107) comprising a guide surface (107a). At least a portion of the guide surface (107a) has a structured contact surface (107b) intended to come into contact with the pivot (21) which it guides. The invention also relates to a method of manufacturing said bearing. The structure of the substrate is modified in an area defined by exposure to a femtosecond laser, this modified structure being preferably removed by chemical etching, to thus form for example protrusions (107b) with capillary effect or elastic members holding the central part ( 106) shock absorbing.
    公开号:CH715419A2
    申请号:CH01297/19
    申请日:2019-10-11
    公开日:2020-04-15
    发明作者:Yoakim Nicolas；Dordor Sébastien
    申请人:Richemont Int Sa；
    IPC主号:
    专利说明:

    Technical area
    The present invention relates to a bearing for guiding a timepiece, in particular a balance, characterized by a geometry of three-dimensional type, which can advantageously be carried out in a single step of a microfabrication process, and having advantageous tribological properties during its operation with the tree with which it is intended to cooperate. The invention also relates to a shock-absorbing bearing or shock-absorbing bearing.
    State of the art
    In a mechanical watch movement, the axes of the balance and the moving parts of the escapement and the gear train are terminated by pivots guided in bearings. These pivots are generally quite thin, and therefore fragile. Furthermore, due to this relative rotational movement, there is some wear of the two surfaces in contact and their relative friction reduces the performance of the system.
    The anti-shock bearings are designed to protect the pivots by allowing, during an impact, an axial and / or radial movement of the axis of the mobile against elastic means until a part of the axis more resistant than the pivots abuts against a fixed bearing of the bearing, the elastic means returning the axis to its initial position after the impact.
    Document JP 2011 180 006 describes a shock absorber bearing with ball bearing. In this case, due to the different parts present to form the bearing, and in particular balls, there are many stages of manufacture and assembly. In addition, it is necessary to adapt the dimensions and the manufacturing range of the bearing and its balls for each bearing of the timepiece.
    Document WO 2013 092 924 describes a timepiece component, in particular a bearing or a pallet of anchor, produced by a selective structuring process and comprising a reservoir intended to contain liquid which cooperates through a channel opening onto the pivot housing in order to lubricate it. However, the channels connecting the reservoirs to the hole must be dimensioned so as to ensure the ideal flow of liquid towards the hole, which makes the operations of filling and changing the liquid as well as of the cleaning of the bearing very complicated. In addition, the contact surface of the bearing described in this document is not structured so as to limit friction with the tigeron with which it is associated, contrary to the object of the present invention.
    Document CH 702 314 describes a monobloc bearing made of a crystalline material and comprising a flared hole for accommodating a tigeron, this hole comprising flat surfaces resulting directly from the machining process and located in crystalline planes of the part. This limitation excludes the texture of the walls / surfaces of the hole.
    Document JP 2012 117 842 describes a bearing associated with an axis, as well as a means of lubricating it. The bearing is structured on the surface cooperating with a bearing of the shaft, this in order to promote lubrication. This document therefore proposes to carry out structuring on a plane bearing surface of the pivot, with part of these structuring which cooperates with the pivot to dispense the oil, but does not in any case suggest or suggest to structure the planned bore. to receive the pivot.
    Document EP 2 226 689 describes a bridge made of micromachined material. The bridge has machined holes intended to receive an axis. The olivage of the hole makes it possible to maintain a reserve of lubricant in the surroundings. This geometry is not, however, a structuring, and the manufacturing methods described for carrying out the oliving do not allow complex structures to be produced along the wall of the hole.
    Document CH 710 846 describes a timepiece component, one surface of which is a surface formed by a network of microcavities, these being configured to serve as a reservoir for a lubricating substance. The processes combined with the materials, however, do not allow obtaining complex geometries.
    Brief summary of the invention
    An object of the present invention is to provide a solution free from the limitations of known bearings.
    Another object of the invention is to provide a bearing that is easy to manufacture, whether for small series or large series.
    Another object of the invention is to provide a bearing whose tribological properties are satisfactory during its operation with the pivot with which it must cooperate.
    According to the invention, these objects are achieved in particular by means of a bearing for a timepiece, produced in a single block in a substrate transparent to the wavelength of a laser, and comprising a central part delimiting a hole intended to guide a tigeron, the hole comprising a guide surface; at least a portion of the guide surface comprising a structured contact surface, intended to come into contact with the tiger that it guides. It is understood that the geometry of this bearing makes it possible to have a reduced contact surface between the bearing and the shaft which it receives and which it guides. Indeed, the surface of the wall of the hole, which can be based on a surface of revolution (such as a cylinder of circular section or a hyperboloid with a sheet) or on a faceted surface of constant section (such as a polygonal prism) or variable, preferably has protruding portions in the direction of the axis of the hole. Thus, it is these projecting portions which are the preferred points, lines or contact surfaces. Another embodiment of the invention consists in carrying out submicron structuring on the surface, which also results in privileged contact surfaces. Indeed, in all cases the extent of the surfaces in contact between the shaft and the pivot is reduced.
    This solution has the particular advantage over the prior art of having a bearing with improved tribological properties, whether used in combination with a liquid lubricant or not.
    Preferably, said geometric structuring comprises at least one of the following geometric objects: spherical ring, sphere cap, any convex surface portion or any other geometry resulting in points, lines or contact surfaces arranged on at least a circle coaxial with the axis of the hole. These geometric objects form possible surfaces, lines and / or points of contact between the wall of the hole and the pivot. The structured contact surface resulting from the aforementioned intersection may include several of these objects, in particular several spherical rings, sphere caps or portions of convex surface, distant from each other.
    In one embodiment, the structured contact surface has protrusions of hemispherical shape. Such protrusions provide a geometry which greatly reduces the contact surfaces, and therefore the friction forces between the bearing and the pivot of the shaft, and this in different relative positions between the bearing and the pivot that it receives.
    Advantageously, the structured contact surface has at least three protuberances distributed in a plane orthogonal to the axis of the pivot. The presence of three or more points of contact between the bearing and the tigeron, in the same plane orthogonal to the axis of the pivot, provides reduced friction.
    In one embodiment, said bearing further comprises elastic members allowing a translation of the central part defining the hole along at least one axis. Such elastic members are preferably arranged between the central part and the edge of the bearing, whereby the bearing is a shock absorbing bearing. In this way, a bearing is produced which makes it possible both to perform improved tribological functions and also forming an anti-shock absorber. Advantageously, the elastic members are three-dimensional, that is to say that their elastic component is not contained in a single plane, which makes it possible to accommodate very varied geometries and form a more or less flexible or rigid damping, operating in one or more preferred directions. This also has the advantage of being able to reduce the bulk of the bearing without reducing the active length of the elastic arms, by using geometries extending over several planes, such as for example serpentine type geometries.
    Brief description of the figures
    Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:<tb> fig. 1 <SEP> illustrates a first embodiment of a bearing for a timepiece according to the invention;<tb> fig. 2 <SEP> illustrates detail II of fig. 1;<tb> fig. 3 <SEP> illustrates a second embodiment of a bearing for a timepiece according to the invention;<tb> fig. 4a and 4b <SEP> illustrate a third and a fourth embodiment of a bearing for a timepiece according to the invention;<tb> fig. 5a and 5b <SEP> illustrate a fifth and a sixth embodiment of a bearing for a timepiece according to the invention;<tb> fig. 6a and 6b <SEP> show the view in partial section of the bearing according to the fifth embodiment, respectively according to section A – A and B – B of FIG. 5a;<tb> fig. 7 <SEP> shows a partially cutaway perspective view of a possible bearing geometry for the variant of the sixth embodiment, from the face of the bearing receiving the pivot,<tb> fig. 8 <SEP> illustrates the bearing of fig. 7 in perspective from the other side of the landing;<tb> fig. 9 <SEP> shows in sectioned perspective a possible bearing geometry for a variant partially similar to the first embodiment;<tb> fig. 10 <SEP> illustrates a sectioned detail of the bearing in FIG. 9;<tb> fig. 11 <SEP> illustrates a seventh embodiment of a bearing for a timepiece according to the invention; and<tb> fig. 12 <SEP> illustrates one of the phases of the process according to the invention in comparison with a technique of the prior art.
    Example (s) of embodiment of the invention
    [0020] FIG. 1 illustrates a first embodiment of a timepiece bearing according to the invention. It is recalled that this bearing is an element serving as a pivot for a shaft of the timepiece.
    This bearing 100 alone forms a pivot system comprising, at the bottom, a base 102 with a hole 103 for the passage of the shaft 20 terminated by a tigeron 21, the base 102 comprising an annular edge 104 forming the radially outer wall of the bearing 100. The bearing 100 comprises in the upper part a central part 106 with a hole 107 of axis P, here a blind hole, for receiving the rod 21 of the pivot. Between the central part 106 and the upper end of the annular edge 104 of the base 102, arms 108 extend from three-dimensional elastic members extend. When a bearing has a shockproof, that is to say that elastic members allow relative movements of the pivot, it is important to be able to limit the travel of the radial and axial movements of the guided mobile to avoid breaking of the tigeron 21 during significant shocks. This function is provided by the base 102 which has a hole 103 to limit the radial movements by retaining the shaft 20 and a bearing 111 to limit the axial movements. In the rest of the text, the term "pivot" is used to describe either the shaft 20 or tigeron 21, intended to cooperate with one of the holes 103 and / or 107.
    According to the invention, the bearing 100 is in one piece, formed in one piece. Preferably the recess 110 existing between the base 102, the arms and the central part 106 is a continuous volume, opening towards at least one surface of the part and which is obtained by etching in the mass of a block of material or substrate initially full.
    Preferably, the bearings according to the invention are produced by the "Selective Laser-induced Etching" (SLE) or "In-Volume Selective Laser-induced Etching" (ISLE) technique.
    To this end, the recess 110 is obtained in the following manner:<tb> a) <SEP> a substrate of dimensions greater than the dimensions of the bearing is provided;<tb> b) <SEP> a laser is supplied with a pulse duration which can range from femtosecond (10 ”15 seconds) to picosecond (10” 12 seconds);<tb> c) <SEP> the structure of the substrate is modified on at least one volume defining a border between the geometry of the desired bearing and the material to be removed;<tb> d) <SEP> a chemical agent is provided which allows the material of the volume of the substrate, the structure of which was modified by the laser in the previous step, to be dissolved more quickly than the other areas of material of which the structure has not been changed;<tb> e) <SEP> exposing, for example in a bath, the substrate with the volume of structure modified to the chemical agent for a predetermined time so that all the material of the volume of structure modified is dissolved ; and<tb> f) <SEP> the exposure of the part thus formed is stopped, for example by removing it from the bath, and all traces of the chemical agent are removed, for example by washing it, and thus stopping the reaction between chemical agent and substrate material.
    We then directly obtain the bearing 100 shown in FIG. 1.
    The modification of the structure of the substrate in step c) is only possible by using a material for the substrate which is transparent for the wavelength of the laser. In practice, at least the contour defined by the border between the volume of the substrate intended to form the recess 110 and the volume of the desired bearing 100 is traversed with the focal point of the laser, point to point. This method has the particular advantage, compared to many chemical etching processes, that only a border area between two volumes of substrate to be separated must be exposed and etched, and not the entire volume to be removed, which greatly accelerates the speed of the process. Obviously, this is only valid for volumes which can be removed entirely, that is to say that their geometry must be extraditable from the substrate after separation. Otherwise, the laser exposure must be done on additional areas, in particular using intermediate cuts, or even total exposure in some cases, in order to remove the unwanted part of the substrate. This produces a modification of the structure of the material by absorption with several photons, which requires a particularly high energy density.
    In step d), the local modification of the structure by the laser makes it possible to choose a chemical agent which is more reactive in the volume of modified structure than in the other unmodified zones. For example, in the case of borosilicate glass, the irradiated area can be dissolved at a rate of up to 300 times that of the rate of dissolution of the unexposed area.
    Thus, preferably, the bearings according to the invention are obtained by a selective chemical attack process, implemented after a prior step of modifying the structure of at least part of the three-dimensional area of the substrate in front be withdrawn. The modified area of the substrate can be removed from the modified area of the substrate by any other means equivalent to chemical etching.
    [0029] FIG. 12 illustrates the advantage of the production process used in the context of this invention. The laser beam shown in solid lines corresponds to that used in the present process. In this case, it makes it possible to reach points internal to the substrate, at varying depths, or arranged on surfaces that are not directly accessible. An example of a conventional process, represented by the dotted line, highlights its limitations. The masked areas or not directly accessible by a laser beam, in particular the bottoms of grooves or holes, cannot be textured. In addition, the areas potentially reachable by a traditional laser cannot be textured with adequate precision or reproducibility. Since the incident beam must be tilted at an angle a to reach the wall of the hole, the sides of the textures cannot be perpendicular to the surface of the hole. In addition, certain texturing geometries cannot be obtained, in particular circular structures.
    The cylindrical surface of the wall of the hole can also cause deformations or a complexity in replicating the pattern of the structuring all around the wall. Thus, for a hole diameter of a value D, with an angle a of approximately 10 °, the maximum depth of structuring of the wall of the hole which can be obtained by a traditional method cannot reasonably exceed a height e = D • tan (α = 10 °), i.e. less than 20% of the hole diameter, which is not sufficient for bearings with deeper guidance. This method makes it possible to obtain a bearing comprising a hole of diameter D comprising the structures having a height e exceeding 20% of the diameter of the hole.
    The present method also makes it possible to produce complex geometries which cannot be obtained by a traditional method, in particular thanks to the possibility of focusing the laser on an area internal to the substrate. This also offers great flexibility in the orientation of the incident laser, which can be aimed at the point to focus from several places. Fig. 12 illustrates some examples of complex structures achievable by the method of the invention. With their geometries, their locations and their number, structural detelles make it possible to control the contact areas of the bearing with the shaft. In addition, the precisely controlled dimensions and geometries, including in particular edges which limit the spread of the lubricant, can make it possible to effectively retain the lubricant on structured surfaces.
    The material used to form the substrate for obtaining one or the other of the bearings according to the invention preferably belongs to the group comprising quartz, natural and synthetic ceramics (comprising in particular sapphire, synthetic ruby , polycrystalline ruby), glasses, vitroceramics, silica, composites and polymers.
    Advantageously, the material used to form the substrate making it possible to obtain one or other of the bearings according to the invention is a non-metallic material which has a hardness greater than 1200 Hv, this hardness corresponding in particular to requirements described in ISO 1112-2009 or NIHS 94-10.
    As can be seen more precisely in FIG. 2, a guide surface 107a of the wall of the hole 107 has a geometric structure, here protrusions 107b. In this example, the guide surface 107a comprises the entire wall of the hole 107, including the wall of the bottom of the hole 107. The guide surface 107a advantageously defines a cylinder of revolution intended to receive the pivot, and to the bottom wall of the hole 107 which receives the end of the tigeron 21a. The guide surface 107a is intended to cooperate with the rod 21 so as to guide it when the latter is received in the hole 107.
    In the example of Figs. 1 and 2, the geometric structuring comprises hemispherical protrusions arranged in a first group on the bottom wall of the hole 107 (above in FIGS. 1 and 2) and in a second group on the side wall of the hole 107. In this last case, the protrusions 107b are distributed in a crown, namely in a plane orthogonal to the axis P of the pivot. In this way, there is a series of contact points between these protrusions 107b arranged in a crown and the rod 21, these contact points being distributed on a circle concentric with the hole 107 and the axis of the pivot. Preferably, these protrusions 107b are distributed equidistantly between them, with the same angular sector measured from the axis P between two neighboring protrusions.
    It is understood that these protrusions delimit very reduced surfaces, most of the time punctual or linear, for contact with the surface of the tigeron 21, which greatly limits friction.
    Thus, the first group of protrusions 107b (at the top in FIGS. 1 and 2) is likely to come into contact with the end of the tigeron 21 formed in this case of a flat face 21a. In the position shown in fig. 1 and 2, the tigeron 21 is not engaged enough in the hole 100 for there to be contact between the first group of protrusions 107b and the flat face 21a. In the same way, the second group of protrusions 107b is capable of coming into contact with the cylindrical lateral wall of the tigeron 21. In practice, this contact occurs on a number of points which may be less than the number of protrusions 107b. In the positions in which the tree is horizontal and subjected to the action of gravity, it will tend to rely on a number of protrusions 107b of the second reduced group, as shown in fig. 6b. In the positions where the shaft is vertical, the contact will be made on the protuberances 107b of the first group, and partially (depending on the existence or not of displacements of the mobile on a plane perpendicular to the axis of the pivot) on protrusions 107b of the second group.
    In general, the geometric structuring comprises protuberances 107b in the form of a portion of a sphere, of a portion of an ovoid shape, of a portion of a paraboloid or of a portion of any convex shape.
    In one embodiment, at least a portion of the surface of the wall of the hole 107 is convex, such as for example a hyperboloid surface with 2 plies. This convexity creates a reduced contact surface with the shaft 20.
    The protrusions 107b can be dimensioned and distributed in such a way that they generate couples of controlled frictions on the tigeron 21. Thus, it is for example possible to calculate the couples of frictions generated by the first and second groups of protuberances on the tigeron and arrange these first and second groups of protrusions so as to obtain friction couples which compensate for, or even cancel out, the variations in speed (mobile), amplitude and / or walking (balance) variations between the positions horizontal and vertical; these calculations can take account of parameters including in particular the respective coefficients of friction of the surfaces in contact, the respective radii of the surfaces of the protrusions and of the tigeron, the radii of the respective contact zones relative to the axis of rotation of the pivot and the number of these effective contact zones in each of the positions.
    In one embodiment, the protrusions 107b have a capillary effect retaining a film of oil around the point (or line, or surface) of contact with the tigeron 21.
    According to the second embodiment of FIG. 3, the difference with the first embodiment which has just been described lies in the fact that only the first group of protrusions 107b located on the bottom wall of the blind hole 107 is present. Here, the tigeron 21 has a pointed end 21a, in particular in the shape of a cone, so that the guiding in rotation takes place essentially by this end 21a. The second group of protrusions 107b of the side wall has been omitted.
    In the first and second embodiments which have just been described, the hole 107 of the bearing is blind. In this case, preferably, the bearing 100 has protrusions 107b on the bottom wall of the blind hole 107.
    According to another embodiment illustrated in FIG. 11, hole 107 is not a blind hole but a through hole.
    Figs. 4a and 4b illustrate a third and fourth embodiment, respectively. According to the third embodiment of the bearing 100 illustrated in FIG. 4a, the geometric structuring comprises submicron ablations 107d which have the effect of reducing the contact surface with the tigeron 21.
    According to the fourth embodiment of the bearing 100 illustrated in FIG. 4b, the hole 107 is an olive hole. The wall 107c of this olive hole is convex between the two ends of the hole 107 with a hole diameter which is reduced between each of the two ends of the hole 107 and an intermediate portion, located for example in the middle of the length of the hole 107 This olive shape makes it possible to concentrate the contact zone on a narrow circular strip, situated approximately in the middle of the length of the hole 107. Another known advantage of this geometry is that it allows a relatively stable behavior even if the axis of the tigeron 21 is not parallel to the axis of the bearing.
    According to a feasible arrangement for all embodiments and visible at the hole 103 of the base 102 of the third and fourth embodiments of the bearing 100 (fig. 4a and 4b), a leave 112 can be added directly to the bearing in the same operation on all the edges requiring such a geometry, whether it is to facilitate the guiding of the tigeron 21 during its installation, to facilitate the driving out of the bearing 100 in its support, to limit the risks of wear linked to a sharp edge against a surface in mobile contact, or in general, to soften these edges in order to avoid incipient fractures which may occur during the use of fragile and brittle materials. In this way, the wall of the hole 103 has a rounded end on the side where the shaft 20 engages in the hole, this leave 112 being favorable for limiting friction and for guiding the tigeron 21 during its introduction into the hole 103.
    In FIG. 4b, the arms 108 are shown in section in a variant in the form of arms 108 ́ whose thickness (dimension in the direction of the axis P of the central part 106) is not constant as for the arms 108, but is variable in radial direction, this in order to distribute the stresses. This variation in thickness can range from a simple fillet in the corners to a beam-type profile with variable section.
    In fig. 4a, complementary arms 109 are shown in section, in phantom. These complementary arms 109 connect the central part 106 to the annular edge 104, at the bottom of the bearing 100, namely on the side of the hole 107 through which the tigeron 21 is introduced.
    Figs. 5a and 5b show a fifth and a sixth embodiment with a central part 106 similar to that of the first embodiment, with the difference that the tigeron is terminated by a rounded profile. We see there the two series of protrusions 107b of the wall of the blind hole 107. FIGS. 6a and 6b show a partial sectional view of the bearing 100 showing the central part 106 according to the fifth embodiment, respectively according to the section A – A and B – B of FIG. 5a. Thus, in fig. 6a, there are the three hemispherical protrusions 107b of the bottom wall of the blind hole 107, in contact with the rounded end of the tigeron 21. In FIG. 6b, the cut is made in the middle part of the height of the hole 107 and there are eight hemispherical protrusions 107b of the side wall of the blind hole 107, 2 of which are in contact with the tigeron 21 (indicated by the symbol 107b 'in Fig. 6b).
    In FIG. 5a, femtosecond laser exposure of an area of the elastic organs results in a modification of the local volume of the material. In this figure, an example of an exposed area is shown by the shaded portion 1008. This local change in the material can cause a modification of the local elastic properties. Depending on the orientation and location of the stresses or prestresses in the elastic members 108, it is also possible to modify the linearity of their response to displacements, for example by favoring a different response to small displacements than the response to large ones. displacements.
    This structural modification can be carried out in an additional step prior to the etching of the bearing 100, if the exposed zones do not extend to the surface of the bearing, so as not to expose these zones to the chemical agent. of etching, the exposure parameters of this modified zone 1008 of the bearing 100 varying however from the exposure parameters of the zone to be removed to obtain the geometry of the bearing. This operation can also take place at any time after the bearing has been cut by the method described above.
    In FIG. 5b, a variant of the first embodiment is proposed, there again with elastic members 108 extending over a length greater than the length available between the annular edge 104 and the central part 106, the distribution of this geometry in space being chosen in a form reminiscent of an accordion.
    We refer to Figs. 7 and 8 showing in perspective a possible bearing geometry for the variant of the fifth embodiment. In fig. 7, this bearing 100 is seen from its face by which the tigeron 21 (not shown in FIGS. 7 and 8) is introduced. We find there the hole 103, the blind hole 107 fitted with protuberances 107b, the annular border 104, the base 102 and the arms 108 forming wavy radial blades between the central part 106 and the border 104.
    In FIG. 8, this bearing 100 is shown from the other face of the bearing, the hole 107 for introducing the tigeron 21 then being hidden by its bottom wall.
    FIG. 9 shows in sectioned perspective a possible geometry of the bearing 100 for a variant partially similar to the first embodiment. Fig. 10 illustrates an uncut detail of the bearing of FIG. 9.
    According to the third embodiment (Fig. 4a), the protrusions 107b, or more generally the areas of the wall of the hole 107 of the central pivot in contact with the rod 21, have a surface with a structure submicron controlled 107d. The expression “controlled submicron structuring” means a structuring produced voluntarily on the surface of the wall of the hole 107, by structuring means, the structuring means in this case being directly those of the initial etching process of the bearing, and these controlled submicron structures 107d can be produced during the initial cutting of the bearing, or in a subsequent step. In fact, one of the properties of exposure to a femtosecond laser resides in etchings which can be considerably smaller than the diameter of the beam which generates them, controlled submicron structures 107d can be produced at the surface of the material, Alternatively, the Controlled submicron structuring can be machined using a DLIP (Direct Laser Interference Patterning) method. The controlled submicron structuring 107d makes it possible to improve at least locally the tribological properties between the wall of the hole 107 and the tigeron 21. The controlled submicronic structuring 107d also makes it possible to vary the wettability of the surface of the wall of the hole 107. Indeed , some structures can be dimensioned so as to assume an oleophilic function 107d ́, to retain the oil, while others can be dimensioned so as to assume an oleophobic function 107d ́ ́, to prevent spreading of the oil . The variation in contact voltages obtained can advantageously supplement or even replace other types of solutions aimed at a similar effect, such as for example an epilam treatment.
    Such structuring of the surface is specifically controlled unlike the structures corresponding to the intrinsic roughness of a surface in its natural state or after a manufacturing step (for example etching) for the shaping of the core of the material. For this, structures are formed on the surface by a step of shaping the surface which allows control of their geometry (height, width, angle of inclination, general shape), their distribution and their density. These structures can have different polarities with respect to the surface, i.e. they can be pillar / hill (positive polarity) or hole / valley (negative polarity) shape. For example, the surface of the wall of the hole has a coating made of a material different from the material of the substrate, and having tribological properties more favorable than the material of the substrate.
    This controlled submicron structuring is carried out by adapting the surface and depth dimensions of the roughness obtained according to the dynamic and geometric characteristics of the shaft 20 guided by the bearing 100. Without departing from the invention, the different types of structuring 107b, 107c and 107d, 107d ́ and 107d ́ ́ can be combined with each other.
    According to another embodiment, the surface of the wall of the hole 107 comprises a coating made of a material different from the material of the substrate, and having tribological properties more favorable than the material of the substrate. For example, such a coating is obtained by a growth method, in particular an epitaxial growth method.
    In one embodiment which can be combined with any of the preceding embodiments, one or more surfaces of the bearing 100 are polished by a local material recasting operation, known under the term “laser polishing " Indeed, by exposure to a laser beam having different properties (wavelength, energy level, frequency and duration of pulses) of the beams used for the previous operations, it is possible to remelt the material on the surface.
    This polishing operation by redesigning the material makes it possible, on the one hand, to reduce the roughness very significantly. Indeed, by melting the material on the surface, the roughness ridges are flattened to fill the roughness, which offers a very smooth surface but also respecting at best the nominal dimensions, since there is no removal of material unlike conventional polishing operations. The recast polishing operation thus improves the tribological properties of the areas in contact with the pivot 21 which it receives. The recasting polishing operation also makes it possible to reduce or eliminate microcracks or other defects on the surface of the bearing 100, which, in the case of fragile materials such as glasses for example, reinforces the resistance of the bearing, especially its elastic organs.
    This redesign polishing can be achieved by exposure to a carbon dioxide laser, a carbon monoxide laser, or any other source that achieves the same goal.
    The bearing 100 of the invention can be integrated into a timepiece component having at least one additional function.
    Reference numbers used in the figures
    [0065]<tb> p <SEP> Pivot axis, bearing axis<tb> 20 <SEP> Timepiece tree<tb> 21 <SEP> Pivot, tigeron<tb> 21a <SEP> End of pivot (tigeron)<tb> 100 <SEP> Level<tb> 102 <SEP> Base<tb> 103 <SEP> Hole<tb> 104 <SEP> Border<tb> 106 <SEP> Central part<tb> 107 <SEP> Hole<tb> 107a <SEP> Guide surface<tb> 107b <SEP> Protuberances<tb> 107c <SEP> Olive hole wall<tb> 107d <SEP> submicronic structuring<tb> 107d ́ <SEP> oleophilic submicron structuring<tb> 107d ́ ́ <SEP> oleophobic submicron structuring<tb> 108 <SEP> Arm<tb> 108 ́ <SEP> Arm<tb> 108 ́ ́ <SEP> Arm<tb> 108 ́ ́ ́ <SEP> Arm<tb> 1008 <SEP> Exposed area of the arm<tb> 109 <SEP> Complementary arm<tb> 110 <SEP> Obviously<tb> 111 <SEP> Scope<tb> 112 <SEP> Leave
    权利要求:
    Claims (26)
    [1]
    1. Bearing (100) for a timepiece, produced in a single block in a substrate transparent to the wavelength of a laser, and comprising a central part (106) delimiting a hole (107) intended to guide a tiger (21), the hole (107) comprising a guide surface (107a), characterized in that at least a portion of the guide surface (107a) has a structured contact surface (107a – 10d), intended for come into contact with the tigeron (21) that it guides.
    [2]
    2. A bearing (100) according to claim 1, in which the structured contact surface is obtained by a method comprising a selective etching step.
    [3]
    3. Bearing (100) according to one of claims 1 or 2, wherein the hole (107) is a blind hole terminated by a wall.
    [4]
    4. Bearing (100) according to the preceding claim, wherein the geometry of the wall ending the hole (107) can be a plane, a surface of revolution or a faceted surface.
    [5]
    5. Bearing (100) according to one of the preceding claims, wherein the guide surface (107a) comprises a plurality of protrusions (107b) each forming a contact with at least one surface of the tigeron (21) which it receives.
    [6]
    6. Bearing (100) according to the preceding claim, wherein said contact is a point or linear contact.
    [7]
    7. Bearing (100) according to the preceding claim, wherein said protrusions (107b) have a capillary effect retaining a film of oil around the point of contact with the tiger (21).
    [8]
    8. Bearing (100) according to one of claims 5 to 7, wherein the protrusions are distributed on at least one plane orthogonal to the axis (P) of the hole (107).
    [9]
    9. Bearing (100) according to the preceding claim, wherein the protrusions are dimensioned and distributed in such a way that they generate couples of controlled friction on the tiger (21).
    [10]
    10. Bearing (100) according to one of the preceding claims, wherein said hole (107) is an olive hole.
    [11]
    11. Bearing (100) according to one of the preceding claims, in which at least one surface of the bearing (100) has at least one configuration of controlled submicron structuring.
    [12]
    12. A bearing (100) according to claim 11, in which the controlled submicron structuring makes it possible to vary the wettability of the surface.
    [13]
    13. The bearing (100) according to claim 12, in which the submicron structuring has at least one oleophilic function and / or one oleophobic function.
    [14]
    14. Bearing (100) according to one of the preceding claims, in which at least one surface has a coating made of a material different from that of the substrate, said material having tribological properties more favorable than those of the substrate.
    [15]
    15. Bearing (100) according to one of the preceding claims, further comprising elastic members (108, 108 ́, 108 ́ ́, 108 ́ ́ ́) allowing a translation of the central part (106) along at least one axis (P).
    [16]
    16. Bearing (100) according to the preceding claim, wherein the elastic members (108, 108 ́, 108 ́ ́, 108 ́ ́ ́) are arranged between the central part (106) and the edge (104) of the bearing (100 ), so that the bearing (100) has a shock absorbing function.
    [17]
    17. Bearing (100) according to the preceding claim, wherein the elastic members (108, 108 ́, 108 ́ ́, 108 ́ ́ ́ ́) are formed beyond a single plane.
    [18]
    18. Bearing (100) according to one of claims 15 to 17, in which the elastic members (108, 108 ́, 108 ́ ́, 108 ́ ́ ́ ́) have a local volume modified by femtosecond laser modifying the elastic properties and / or dimensional of these.
    [19]
    19. Bearing (100) according to one of the preceding claims, made of a material chosen from quartz, natural or synthetic ceramics, glasses, vitroceramics, silica, composites and polymers.
    [20]
    20. Bearing (100) according to one of the preceding claims, made of a non-metallic material which has a hardness greater than 1200 Hv.
    [21]
    21. Bearing (100) according to one of the preceding claims, wherein the bearing is integrated into a timepiece component having at least one additional function.
    [22]
    22. Timepiece comprising a bearing (100) according to one of the preceding claims.
    [23]
    23. Method of manufacturing the bearing (100) according to one of claims 1 to 20, comprising the steps of:modify the structure of at least one area of the substrate by exposure to a femtosecond laser; andremove the modified area from the substrate.
    [24]
    24. The method according to claim 23, in which the modified zone is removed from the substrate by chemical etching.
    [25]
    25. The method of claim 23 or 24, wherein at least one surface of the bearing is exposed to a polishing operation by local recasting of the material.
    [26]
    26. The method according to the preceding claim, wherein the polishing by recasting is carried out by exposure to a laser with carbon dioxide or carbon monoxide.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP3929667A1|2020-06-26|2021-12-29|ETA SA Manufacture Horlogère Suisse|Rotating mobile system of a clock movement|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    CH12402018|2018-10-11|
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