EP3367182A1 - Low-friction shaft support bearing - Google Patents

Low-friction shaft support bearing Download PDF

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Publication number
EP3367182A1
EP3367182A1 EP17157667.1A EP17157667A EP3367182A1 EP 3367182 A1 EP3367182 A1 EP 3367182A1 EP 17157667 A EP17157667 A EP 17157667A EP 3367182 A1 EP3367182 A1 EP 3367182A1
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EP
European Patent Office
Prior art keywords
bearing
axis
recess
hole
sintered
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP17157667.1A
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German (de)
French (fr)
Inventor
Laurent Kaelin
Pascal CHOPARD-LALLIER
Bruno Besutti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Comadur SA
Original Assignee
Comadur SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Comadur SA filed Critical Comadur SA
Priority to EP17157667.1A priority Critical patent/EP3367182A1/en
Priority to EP17808805.0A priority patent/EP3519902B1/en
Priority to CN201780079616.4A priority patent/CN110114731B/en
Priority to PCT/EP2017/079302 priority patent/WO2018114149A1/en
Priority to US16/344,237 priority patent/US11036186B2/en
Priority to JP2019524233A priority patent/JP6901558B2/en
Priority to KR1020197012887A priority patent/KR102234880B1/en
Priority to TW106141127A priority patent/TWI786075B/en
Publication of EP3367182A1 publication Critical patent/EP3367182A1/en
Withdrawn legal-status Critical Current

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    • G—PHYSICS
    • G04—HOROLOGY
    • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
    • G04B31/00—Bearings; Point suspensions or counter-point suspensions; Pivot bearings; Single parts therefor
    • G04B31/004—Bearings; Point suspensions or counter-point suspensions; Pivot bearings; Single parts therefor characterised by the material used
    • G04B31/008—Jewel bearings
    • G04B31/0087—Jewel bearings with jewel hole only
    • G—PHYSICS
    • G04—HOROLOGY
    • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
    • G04B31/00—Bearings; Point suspensions or counter-point suspensions; Pivot bearings; Single parts therefor
    • G04B31/004—Bearings; Point suspensions or counter-point suspensions; Pivot bearings; Single parts therefor characterised by the material used
    • G04B31/012—Metallic bearings
    • G04B31/0126—Metallic step-bearings

Definitions

  • the present invention relates to a bearing in which is pivotable an axis, the axis comprising at least one end a reach through which the axis is in contact with a surface facing the bearing, said bearing being extended by a pivot engaged in a hole in the landing.
  • a bearing is particularly used in the field of watchmaking.
  • the wheel To drive a wheel in rotation in a clockwork movement, it is known to fix the wheel on an axis comprising at least one of its ends a range extended by a pivot.
  • the axis is positioned between two bearings each comprising a hole in which is housed a pivot axis. According to the chosen construction method, the range of one end of the axis or the range of each end of the axis comes into contact with a surface facing the associated bearing. Both bearings guide the axis in rotation while prohibiting its axial translation.
  • the oil layer between the axis of the axis and the surface facing the bearing is particularly thin so that there is an effect bonding between the scope of the axis and the surface facing the bearing and, when the axis rotates, a shearing force of the oil layer comes to oppose the rotation of the axis.
  • the present invention aims at improving the known technique, by proposing a solution for reducing the shearing force at the level of the oil layer present between the bearing of an axis and the surface opposite a bearing in which the axis is rotated.
  • the present invention relates to a bearing in which an axis rotates, the axis comprising at one end a bearing surface through which the pin is in contact with a surface facing the bearing, said bearing being extended by a pivot engaged in a hole in the bearing, the bearing surface facing the axis of the bearing including at least one recess to reduce the contact area between the bearing axis and the bearing.
  • the recess is in the form of a ring centered on the bearing hole.
  • the effect ie the torque produced by the elementary shear force, is the product of this shearing force by the distance between the axis of rotation and the point of application of the elementary force.
  • the surface opposite the bearing by which the bearing surface of the axis is in contact with the bearing is provided with a plurality of recesses distributed around the hole of the bearing. The reduction of the effect of the shearing force is thus more homogeneous between the bearing of the axis and the surface of the bearing opposite the span of the axis.
  • the present invention proceeds from the general inventive idea of limiting the contact surface between the range of an axis and the surface facing a bearing maintaining said axis.
  • the invention proposes a new bearing whose general shape limits said contact surface.
  • the figure 1 shows schematically the implementation of bearings according to the invention for driving in rotation of a toothed wheel of a watch movement.
  • the toothed wheel 20 is fixed on an axis 30 comprising at each end a bearing 31a, 31b extended by a pivot 32a, 32b.
  • the axis 30 is rotatably mounted between two bearings 10a, 10b according to the invention.
  • the bearings 10a, 10b are immobilized in a frame 21.
  • These bearings 10a, 10b comprise, in a known manner, a hole 11, preferably centered, which passes right through them. Note that the wall of the hole 11 may include an olivage to minimize contact with the pivots 32a, 32b and facilitate possible lubrication.
  • a pivot 32a, 32b of the axis 30 guided in rotation by the bearing 10a or 10b corresponding is housed in the hole 11.
  • the bearing 31a, 31b of the axis 30 comes into contact with a surface 12 facing the bearing 10a, 10b, so that the axis 30 is immobilized in axial translation, with a game near, between the bearings 10a, 10b.
  • the hole 11 opens into a recess 13 of preferentially conical shape.
  • This hollow 13, commonly called oiler in the field of watchmaking, may be intended to receive a drop of oil.
  • the other end of the hole 11 is slightly flared to facilitate the infiltration of the oil between the bearing 10a, 10b and the bearing 31a, 31b at the contact surface 12. It will be understood that this recess is optional and that it will be provided only in the case where it is desired to lubricate the pivoting of the axis 30 in the bearing 10a, 10b.
  • a bearing 10a, 10b according to the invention is characterized by a recess 14 for reducing the contact surface 12 between the bearing 31a, 31b of the axis 30 and the bearing 10a, 10b.
  • the recess 14 is made on the opposite side to the recess 13, in the contact surface 12 of the bearing 10a, 10b which is opposite the bearing surface 31a, 31b of the axis 30.
  • the recess 14 has an annular shape.
  • the residual contact surface 12 between the bearing surface 31a, 31b of the axis 30 and the bearing 10a, 10b thus has the shape of two concentric inner 12a and outer 12b rings.
  • the inner radius R0 of the inner ring 12a is substantially equal to the radius of the hole 11, while the outer radius R1 of the inner ring 12a is equal to the radius Inside the recess 14.
  • the outer concentric ring 12b it is between an inner radius R2 equal to the outer diameter of the recess 14, and an outer radius R3.
  • the diameter R1 must be sufficient to ensure proper maintenance of the axis 30 in the hole 11.
  • a plurality of recesses 14 are hollowed on the surface of the bearing 10a, 10b around the hole 11.
  • six recesses 14 are evenly spaced, arranged concentrically around the pivot 32a, 32b of the axis 30 and opening into the flared end of the hole 11.
  • the dimensions of the bearings are small, from less than 1 mm to a few millimeters for the largest dimension.
  • the production of a bearing according to the invention is therefore delicate and requires specific tools.
  • the bearing 10a, 10b is made of a monocrystalline hard material such as ruby, corundum, spinel or else cubic zirconia and the recesses 14 are machined by ablation of material by means of a laser beam, by electroerosion or by grinding.
  • the bearing 10a, 10b is made of a hard sintered material such as corundum, ruby, ceramics, alumina, zirconia or even a hard metal and the recesses 14 are made by stamping or machined by ablation. This technique is described in particular in the document EP 2 778 801 A1 in the name of the Claimant.
  • the process includes a first step for forming a ceramic precursor from a ceramic-based powder taken in a binder.
  • This ceramic-based powder may comprise at least one metal oxide, a metal nitride or a metal carbide.
  • the ceramic powder may comprise aluminum oxide to form synthetic sapphire or a mixture of aluminum oxide and chromium oxide to form synthetic ruby.
  • the binder it can be of the polymer type or of the organic type.
  • the method comprises a second step intended to compress, with the aid of an upper die and a lower die which is brought closer to one another, the ceramic precursor to form a green body of the future bearing. 10a, 10b with upper and lower surfaces respectively comprising at least one recess 14 and, where appropriate, a recess 13. It is therefore understood that each green body thus formed already comprises the blanks of the recess 14 and the recess 13.
  • each substantially planar matrix comprises at least one punch intended to form the recess 14 and, optionally, the recess 13.
  • the upper die comprises a punch with a substantially annular surface for forming the recess 14
  • the lower die comprises a punch with a substantially conical surface for forming the recess 13.
  • the green body is sintered to form a ceramic bearing 10a, 10b and the hole 11 is drilled to connect the upper surface and the lower surface of the bearing 10a, 10b together.
  • This step is preferably carried out using destructive radiation of the laser type in order to obtain a very precise etching. However, this step can be performed for example by mechanical drilling or etching with high pressure water.
  • the present invention is not limited to the embodiments which have just been described and that various modifications and simple variants can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims. It will be noted in particular that in its basic embodiment, the present invention applies to the case in which only one of the two bearings 10a, 10b which guide the axis 30 is provided in its contact surface 12 with the bearing surface 31a. or 31b of pivot 32a or 32b corresponding to a recess 14 according to the invention. The case in which the two bearings 10a, 10b each have a recess 14 for reducing the extent of the contact surface 12 with the bearing surfaces 31a and 31b of the pivots 32a and 32b is of course also considered.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Sliding-Contact Bearings (AREA)

Abstract

Palier dans lequel pivote un axe (30), l'axe (30) comprenant à au moins une extrémité une portée (31 a, 31 b) via laquelle l'axe (30) est en contact avec une surface (12) en regard du palier (10a, 10b), la portée (31 a, 31 b) étant prolongée par un pivot (32a, 32b) engagé dans un trou (11) ménagé dans le palier (10a, 10b). La surface de contact (12) en regard du palier (10a, 10b) comprend au moins un évidement (14) afin de réduire la surface de contact entre la portée (31 a, 31 b) de l'axe (30) et le palier (10a, 10b).Bearing in which an axis (30) pivots, the axis (30) comprising at least one end a bearing surface (31a, 31b) through which the axis (30) is in contact with a surface (12) facing bearing (10a, 10b), the range (31a, 31b) being extended by a pivot (32a, 32b) engaged in a hole (11) formed in the bearing (10a, 10b). The contact surface (12) facing the bearing (10a, 10b) comprises at least one recess (14) to reduce the contact area between the bearing surface (31a, 31b) of the axis (30) and the bearing (10a, 10b).

Application à la réalisation d'un palier pour un axe de mouvement horloger.

Figure imgaf001
Application to the realization of a bearing for a watch movement axis.
Figure imgaf001

Description

Domaine technique de l'inventionTechnical field of the invention

La présente invention concerne un palier dans lequel est susceptible de pivoter un axe, l'axe comprenant à au moins une extrémité une portée via laquelle l'axe est en contact avec une surface en regard du palier, ladite portée étant prolongée par un pivot engagé dans un trou ménagé dans le palier. Un tel palier est notamment utilisé dans le domaine de l'horlogerie.The present invention relates to a bearing in which is pivotable an axis, the axis comprising at least one end a reach through which the axis is in contact with a surface facing the bearing, said bearing being extended by a pivot engaged in a hole in the landing. Such a bearing is particularly used in the field of watchmaking.

Arrière-plan technologique de l'inventionTechnological background of the invention

Pour entraîner une roue en rotation dans un mouvement d'horlogerie, il est connu de fixer la roue sur un axe comprenant à au moins une de ses extrémités une portée prolongée par un pivot. L'axe est positionné entre deux paliers comprenant chacun un trou dans lequel est logé un pivot de l'axe. Selon le mode de construction retenu, la portée d'une extrémité de l'axe ou la portée de chaque extrémité de l'axe vient en contact avec une surface en regard du palier associé. Les deux paliers guident l'axe en rotation tout en interdisant sa translation axiale.To drive a wheel in rotation in a clockwork movement, it is known to fix the wheel on an axis comprising at least one of its ends a range extended by a pivot. The axis is positioned between two bearings each comprising a hole in which is housed a pivot axis. According to the chosen construction method, the range of one end of the axis or the range of each end of the axis comes into contact with a surface facing the associated bearing. Both bearings guide the axis in rotation while prohibiting its axial translation.

Pour limiter les frottements entre la portée de l'axe et le palier, il est connu de réaliser une creusure sur un bord extérieur du trou dans lequel est logé le pivot de l'axe de façon à réaliser un réservoir communément appelé huilier et destiné à recevoir une goutte d'huile. La goutte d'huile présente dans le réservoir s'infiltre par capillarité entre l'axe et les parois du trou du palier et entre la portée de l'axe et la surface du palier en regard de ladite portée. Cette technique permet de réduire les frottements entre l'axe et le palier. Toutefois, la couche d'huile entre la portée de l'axe et la surface en regard du palier est particulièrement fine de sorte qu'on constate un effet de collage entre la portée de l'axe et la surface en regard du palier et, lorsque l'axe tourne, une force de cisaillement de la couche d'huile vient s'opposer à la rotation de l'axe. Ces phénomènes parasites se traduisent par une perte d'énergie que l'on cherche à éviter.To limit the friction between the axis of the bearing and the bearing, it is known to make a recess on an outer edge of the hole in which is housed the axis of the pivot so as to achieve a reservoir commonly called oiler and intended to receive a drop of oil. The drop of oil in the reservoir is infiltrated by capillarity between the axis and the walls of the bearing hole and between the bearing surface of the axis and the surface of the bearing facing said bearing surface. This technique reduces friction between the axis and the bearing. However, the oil layer between the axis of the axis and the surface facing the bearing is particularly thin so that there is an effect bonding between the scope of the axis and the surface facing the bearing and, when the axis rotates, a shearing force of the oil layer comes to oppose the rotation of the axis. These parasitic phenomena result in a loss of energy that we try to avoid.

Résumé de l'inventionSummary of the invention

La présente invention vise à améliorer la technique connue, en proposant une solution pour réduire la force de cisaillement au niveau de la couche d'huile présente entre la portée d'un axe et la surface en regard d'un palier dans lequel l'axe est pivoté.The present invention aims at improving the known technique, by proposing a solution for reducing the shearing force at the level of the oil layer present between the bearing of an axis and the surface opposite a bearing in which the axis is rotated.

A cet effet, la présente invention concerne un palier dans lequel pivote un axe, l'axe comprenant à une extrémité une portée via laquelle l'axe est en contact avec une surface en regard du palier, ladite portée étant prolongée par un pivot engagé dans un trou ménagé dans le palier, la surface du palier en regard de la portée de l'axe comprenant au moins un évidement afin de réduire la surface de contact entre la portée de l'axe et le palier.For this purpose, the present invention relates to a bearing in which an axis rotates, the axis comprising at one end a bearing surface through which the pin is in contact with a surface facing the bearing, said bearing being extended by a pivot engaged in a hole in the bearing, the bearing surface facing the axis of the bearing including at least one recess to reduce the contact area between the bearing axis and the bearing.

En réduisant la surface de contact entre la portée de l'axe et le palier, l'effet de la force de cisaillement de la couche d'huile est réduit. L'axe pivote ainsi plus facilement dans le palier. De plus, même réduite, la surface de contact reste suffisante pour guider l'axe dans le palier.By reducing the contact area between the axle bearing and the bearing, the effect of the shearing force of the oil layer is reduced. The axis thus pivots more easily in the bearing. In addition, even reduced, the contact surface remains sufficient to guide the axis in the bearing.

Selon un mode de réalisation de l'invention, l'évidement se présente sous la forme d'un anneau centré sur le trou du palier. L'effet, c'est-à-dire le couple produit par la force élémentaire de cisaillement, est le produit de cette force de cisaillement par la distance entre l'axe de rotation et le point d'application de la force élémentaire. En réalisant un évidement annulaire éloigné du pivot de l'axe, on réduit ainsi d'autant plus les effets de la force de cisaillement.According to one embodiment of the invention, the recess is in the form of a ring centered on the bearing hole. The effect, ie the torque produced by the elementary shear force, is the product of this shearing force by the distance between the axis of rotation and the point of application of the elementary force. By making an annular recess away from the pivot axis, thus further reduces the effects of the shear force.

Selon un autre mode de réalisation de l'invention, la surface en regard du palier par laquelle la portée de l'axe est en contact avec le palier est pourvue d'une pluralité d'évidements répartis autour du trou du palier. La réduction de l'effet de la force de cisaillement est ainsi plus homogène entre la portée de l'axe et la surface du palier en regard de la portée de l'axe.According to another embodiment of the invention, the surface opposite the bearing by which the bearing surface of the axis is in contact with the bearing is provided with a plurality of recesses distributed around the hole of the bearing. The reduction of the effect of the shearing force is thus more homogeneous between the bearing of the axis and the surface of the bearing opposite the span of the axis.

Brève description des figuresBrief description of the figures

D'autres caractéristiques et avantages de la présente invention ressortiront plus clairement de la description détaillée qui suit d'exemples de réalisation de paliers selon l'invention. Ces exemples sont donnés à titre purement illustratif et non limitatif et sont à lire en liaison avec les dessins annexés sur lesquels :

  • la figure 1 est une vue d'une roue d'un mouvement horloger montée rotative entre deux paliers selon l'invention ;
  • la figure 2 est une vue de dessus d'un palier selon l'invention, et
  • la figure 3 est une vue de dessus d'un autre palier selon l'invention.
Other features and advantages of the present invention will emerge more clearly from the following detailed description of embodiments of bearings according to the invention. These examples are given for purely illustrative and nonlimiting purposes and are to be read in conjunction with the accompanying drawings in which:
  • the figure 1 is a view of a wheel of a clockwork movement rotatably mounted between two bearings according to the invention;
  • the figure 2 is a top view of a bearing according to the invention, and
  • the figure 3 is a top view of another bearing according to the invention.

Description détaillée d'un mode de réalisation de l'inventionDetailed description of an embodiment of the invention

La présente invention procède de l'idée générale inventive qui consiste à limiter la surface de contact entre la portée d'un axe et la surface en regard d'un palier maintenant ledit axe. A cet effet, l'invention propose un nouveau palier dont la forme générale permet de limiter ladite surface de contact.The present invention proceeds from the general inventive idea of limiting the contact surface between the range of an axis and the surface facing a bearing maintaining said axis. For this purpose, the invention proposes a new bearing whose general shape limits said contact surface.

La figure 1 montre schématiquement la mise en oeuvre de paliers selon l'invention pour l'entraînement en rotation d'une roue dentée d'un mouvement horloger.The figure 1 shows schematically the implementation of bearings according to the invention for driving in rotation of a toothed wheel of a watch movement.

La roue 20 dentée est fixée sur un axe 30 comprenant à chaque extrémité une portée 31 a, 31 b prolongée par un pivot 32a, 32b. L'axe 30 est monté rotatif entre deux paliers 10a, 10b selon l'invention. Les paliers 10a, 10b, de forme préférentiellement annulaire, sont immobilisés dans un bâti 21. Ces paliers 10a, 10b comprennent, de manière connue, un trou 11, préférentiellement centré, qui les traverse de part en part. On remarque que la paroi du trou 11 peut comprendre un olivage destiné à minimiser le contact avec les pivots 32a, 32b et faciliter une éventuelle lubrification.The toothed wheel 20 is fixed on an axis 30 comprising at each end a bearing 31a, 31b extended by a pivot 32a, 32b. The axis 30 is rotatably mounted between two bearings 10a, 10b according to the invention. The bearings 10a, 10b, of preferentially annular shape, are immobilized in a frame 21. These bearings 10a, 10b comprise, in a known manner, a hole 11, preferably centered, which passes right through them. Note that the wall of the hole 11 may include an olivage to minimize contact with the pivots 32a, 32b and facilitate possible lubrication.

Un pivot 32a, 32b de l'axe 30 guidé en rotation par le palier 10a ou 10b correspondant vient se loger dans le trou 11. La portée 31 a, 31 b de l'axe 30 vient en contact avec une surface 12 en regard du palier 10a, 10b, de sorte que l'axe 30 est immobilisé en translation axiale, à un jeu près, entre les paliers 10a, 10b.A pivot 32a, 32b of the axis 30 guided in rotation by the bearing 10a or 10b corresponding is housed in the hole 11. The bearing 31a, 31b of the axis 30 comes into contact with a surface 12 facing the bearing 10a, 10b, so that the axis 30 is immobilized in axial translation, with a game near, between the bearings 10a, 10b.

Sur une face opposée à la surface de contact 12 entre la portée 31 a, 31 b de l'axe 30 et le palier 10a, 10b, le trou 11 débouche dans une creusure 13 de forme préférentiellement conique. Cette creusure 13, communément appelée huilier dans le domaine de l'horlogerie, peut être destinée à recevoir une goutte d'huile. L'autre extrémité du trou 11 est légèrement évasée pour faciliter l'infiltration de l'huile entre le palier 10a, 10b et la portée 31 a, 31 b au niveau de la surface de contact 12. On comprendra que cette creusure est facultative et qu'elle ne sera prévue que dans le cas où l'on souhaite lubrifier le pivotement de l'axe 30 dans le palier 10a, 10b.On a face opposite to the contact surface 12 between the bearing surface 31a, 31b of the axis 30 and the bearing 10a, 10b, the hole 11 opens into a recess 13 of preferentially conical shape. This hollow 13, commonly called oiler in the field of watchmaking, may be intended to receive a drop of oil. The other end of the hole 11 is slightly flared to facilitate the infiltration of the oil between the bearing 10a, 10b and the bearing 31a, 31b at the contact surface 12. It will be understood that this recess is optional and that it will be provided only in the case where it is desired to lubricate the pivoting of the axis 30 in the bearing 10a, 10b.

Un palier 10a, 10b selon l'invention est caractérisé par un évidement 14 permettant de réduire la surface de contact 12 entre la portée 31 a, 31 b de l'axe 30 et le palier 10a, 10b. L'évidement 14 est réalisé du côté opposé à la creusure 13, dans la surface de contact 12 du palier 10a, 10b qui se trouve en regard de la portée 31 a, 31 b de l'axe 30.A bearing 10a, 10b according to the invention is characterized by a recess 14 for reducing the contact surface 12 between the bearing 31a, 31b of the axis 30 and the bearing 10a, 10b. The recess 14 is made on the opposite side to the recess 13, in the contact surface 12 of the bearing 10a, 10b which is opposite the bearing surface 31a, 31b of the axis 30.

Selon un mode de réalisation illustré à la figure 2, l'évidement 14 a une forme annulaire. La surface de contact 12 résiduelle entre la portée 31 a, 31 b de l'axe 30 et le palier 10a, 10b a ainsi une forme de deux anneaux concentriques intérieur 12a et extérieur 12b. Le rayon intérieur R0 de l'anneau intérieur 12a est sensiblement égal au rayon du trou 11, tandis que le rayon extérieur R1 de l'anneau intérieur 12a est égal au rayon intérieur de l'évidement 14. Quant à l'anneau concentrique extérieur 12b, il est compris entre un rayon intérieur R2 égal au diamètre extérieur de l'évidement 14, et un rayon extérieur R3. Le diamètre R1 doit être suffisant pour garantir un bon maintien de l'axe 30 dans le trou 11.According to an embodiment illustrated in figure 2 , the recess 14 has an annular shape. The residual contact surface 12 between the bearing surface 31a, 31b of the axis 30 and the bearing 10a, 10b thus has the shape of two concentric inner 12a and outer 12b rings. The inner radius R0 of the inner ring 12a is substantially equal to the radius of the hole 11, while the outer radius R1 of the inner ring 12a is equal to the radius Inside the recess 14. As for the outer concentric ring 12b, it is between an inner radius R2 equal to the outer diameter of the recess 14, and an outer radius R3. The diameter R1 must be sufficient to ensure proper maintenance of the axis 30 in the hole 11.

Selon un autre mode de réalisation, plusieurs évidements 14 sont creusés à la surface du palier 10a, 10b autour du trou 11. Dans l'exemple représenté sur la figure 3, six évidements 14 sont régulièrement espacés, agencés de manière concentrique autour du pivot 32a, 32b de l'axe 30 et débouchant dans l'extrémité évasée du trou 11.According to another embodiment, a plurality of recesses 14 are hollowed on the surface of the bearing 10a, 10b around the hole 11. In the example shown in FIG. figure 3 , six recesses 14 are evenly spaced, arranged concentrically around the pivot 32a, 32b of the axis 30 and opening into the flared end of the hole 11.

Dans le domaine de l'horlogerie, les dimensions des paliers sont petites, de moins d'1 mm à quelques millimètres pour la dimension la plus grande. La réalisation d'un palier selon l'invention est donc délicate et nécessite un outillage spécifique.In the field of watchmaking, the dimensions of the bearings are small, from less than 1 mm to a few millimeters for the largest dimension. The production of a bearing according to the invention is therefore delicate and requires specific tools.

Selon une variante, le palier 10a, 10b est réalisé en un matériau dur monocristallin tel que le rubis, le corindon, le spinelle ou bien encore la zircone cubique et les évidements 14 sont usinés par ablation de matière au moyen d'un faisceau laser, par électroérosion ou par meulage.According to one variant, the bearing 10a, 10b is made of a monocrystalline hard material such as ruby, corundum, spinel or else cubic zirconia and the recesses 14 are machined by ablation of material by means of a laser beam, by electroerosion or by grinding.

Selon une autre variante, le palier 10a, 10b est réalisé en un matériau dur fritté tel que le corindon, le rubis, les céramiques, l'alumine, la zircone ou bien encore un métal dur et les évidements 14 sont réalisés par matriçage ou usinés par ablation. Cette technique est notamment décrite dans le document EP 2 778 801 A1 au nom de la Demanderesse.According to another variant, the bearing 10a, 10b is made of a hard sintered material such as corundum, ruby, ceramics, alumina, zirconia or even a hard metal and the recesses 14 are made by stamping or machined by ablation. This technique is described in particular in the document EP 2 778 801 A1 in the name of the Claimant.

Rappelons pour mémoire que le procédé comporte une première étape destinée à former un précurseur céramique à partir d'une poudre à base de céramique prise dans un liant. Cette poudre à base de céramique peut comporter au moins un oxyde métallique, un nitrure métallique ou un carbure métallique. A titre d'exemple, la poudre à base de céramique peut comporter de l'oxyde d'aluminium afin de former du saphir synthétique ou un mélange d'oxyde d'aluminium et d'oxyde de chrome afin de former du rubis synthétique. Quant au liant, il peut être du type polymère ou du type organique.Recall that the process includes a first step for forming a ceramic precursor from a ceramic-based powder taken in a binder. This ceramic-based powder may comprise at least one metal oxide, a metal nitride or a metal carbide. For example, the ceramic powder may comprise aluminum oxide to form synthetic sapphire or a mixture of aluminum oxide and chromium oxide to form synthetic ruby. As for the binder, it can be of the polymer type or of the organic type.

Le procédé comporte une deuxième étape destinée à comprimer, à l'aide d'une matrice supérieure et d'une matrice inférieure que l'on rapproche l'une de l'autre, le précurseur céramique afin de former un corps vert du futur palier 10a, 10b avec des surfaces supérieure et inférieure comportant respectivement au moins un évidement 14 et, le cas échéant, une creusure 13. On comprend donc que chaque corps vert ainsi formé comporte déjà les ébauches de l'évidement 14 et de la creusure 13.The method comprises a second step intended to compress, with the aid of an upper die and a lower die which is brought closer to one another, the ceramic precursor to form a green body of the future bearing. 10a, 10b with upper and lower surfaces respectively comprising at least one recess 14 and, where appropriate, a recess 13. It is therefore understood that each green body thus formed already comprises the blanks of the recess 14 and the recess 13.

Pour obtenir ces ébauches de l'évidement 14 et de la creusure 13, chaque matrice sensiblement plane comporte au moins un poinçon destiné à former l'évidement 14 et, optionnellement, la creusure 13. A cet effet, la matrice supérieure comporte un poinçon avec une surface sensiblement annulaire permettant de former l'évidement 14, et la matrice inférieure comporte un poinçon avec une surface sensiblement conique permettant de former la creusure 13.To obtain these blanks from the recess 14 and the recess 13, each substantially planar matrix comprises at least one punch intended to form the recess 14 and, optionally, the recess 13. For this purpose, the upper die comprises a punch with a substantially annular surface for forming the recess 14, and the lower die comprises a punch with a substantially conical surface for forming the recess 13.

Finalement, le corps vert est fritté afin de former un palier 10a, 10b en céramique et l'on perce le trou 11 afin de relier entre elles la surface supérieure et la surface inférieure du palier 10a, 10b. Cette étape est préférentiellement réalisée à l'aide d'un rayonnement destructif du type laser afin d'obtenir une gravure très précise. Toutefois, cette étape peut être effectuée par exemple par perçage mécanique ou gravure avec de l'eau à haute pression.Finally, the green body is sintered to form a ceramic bearing 10a, 10b and the hole 11 is drilled to connect the upper surface and the lower surface of the bearing 10a, 10b together. This step is preferably carried out using destructive radiation of the laser type in order to obtain a very precise etching. However, this step can be performed for example by mechanical drilling or etching with high pressure water.

Il va de soi que la présente invention n'est pas limitée aux modes de réalisation qui viennent d'être décrits et que diverses modifications et variantes simples peuvent être envisagées par l'homme du métier sans sortir du cadre de l'invention tel que défini par les revendications annexées. On notera en particulier que dans son mode de réalisation de base, la présente invention s'applique au cas dans lequel un seul des deux paliers 10a, 10b qui guident l'axe 30 est muni dans sa surface de contact 12 avec la portée 31 a ou 31 b du pivot 32a ou 32b correspondant d'un évidement 14 conforme à l'invention. Le cas dans lequel les deux paliers 10a, 10b présentent chacun un évidement 14 pour réduire l'étendue de la surface de contact 12 avec les portées 31 a et 31 b des pivots 32a et 32b est bien entendu également considéré.It goes without saying that the present invention is not limited to the embodiments which have just been described and that various modifications and simple variants can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the appended claims. It will be noted in particular that in its basic embodiment, the present invention applies to the case in which only one of the two bearings 10a, 10b which guide the axis 30 is provided in its contact surface 12 with the bearing surface 31a. or 31b of pivot 32a or 32b corresponding to a recess 14 according to the invention. The case in which the two bearings 10a, 10b each have a recess 14 for reducing the extent of the contact surface 12 with the bearing surfaces 31a and 31b of the pivots 32a and 32b is of course also considered.

NomenclatureNomenclature

10a, 10b.10a, 10b.
Paliersbearings
11.11.
TrouHole
12.12.
Surface de contactContact surface
12a.12a.
Anneau concentrique intérieurInternal concentric ring
12b.12b.
Anneau concentrique extérieurOuter concentric ring
R0, R2.R0, R2.
Rayons intérieursInner spokes
R1, R3.R1, R3.
Rayons extérieursOuter rays
13.13.
Creusurehollow
14.14.
Evidementsrecesses
20.20.
RoueWheel
21.21.
Bâtibuilt
30.30.
AxeAxis
31a, 31b.31a, 31b.
Portées de l'axeSpans of the axis
32a, 32b.32a, 32b.
Pivots de l'axePivots of the axis

Claims (6)

Palier dans lequel pivote un axe (30), l'axe (30) comprenant à au moins une extrémité une portée (31 a, 31 b) via laquelle l'axe (30) est en contact avec une surface (12) en regard du palier (10a, 10b), la portée (31 a, 31 b) étant prolongée par un pivot (32a, 32b) engagé dans un trou (11) ménagé dans le palier (10a, 10b), le palier (10a, 10b) étant caractérisé en ce que la surface de contact (12) en regard du palier (10a, 10b) comprend au moins un évidement (14) afin de réduire la surface de contact entre la portée (31 a, 31 b) de l'axe (30) et le palier (10a, 10b).Bearing in which an axis (30) pivots, the axis (30) comprising at least one end a bearing surface (31a, 31b) through which the axis (30) is in contact with a surface (12) facing of the bearing (10a, 10b), the bearing surface (31a, 31b) being extended by a pivot (32a, 32b) engaged in a hole (11) formed in the bearing (10a, 10b), the bearing (10a, 10b) ) being characterized in that the contact surface (12) facing the bearing (10a, 10b) comprises at least one recess (14) to reduce the contact area between the bearing surface (31a, 31b) of the axis (30) and the bearing (10a, 10b). Palier selon la revendication 1, caractérisé en ce que l'évidement (14) se présente sous la forme d'un anneau centré sur le trou (11) du palier (10a, 10b).Bearing according to claim 1, characterized in that the recess (14) is in the form of a ring centered on the hole (11) of the bearing (10a, 10b). Palier selon la revendication 1, caractérisé en ce que la surface de contact (12) entre la portée (31 a, 31 b) de l'axe (30) et le palier (10a, 10b) est pourvue d'une pluralité d'évidements (14) répartis autour du trou (11) du palier (10a, 10b).Bearing according to claim 1, characterized in that the contact surface (12) between the bearing surface (31a, 31b) of the axis (30) and the bearing (10a, 10b) is provided with a plurality of recesses (14) distributed around the hole (11) of the bearing (10a, 10b). Palier selon la revendication 3, caractérisé en ce que les évidements (14) sont régulièrement espacés et agencés de manière concentrique autour du trou (11) du palier (10a, 10b).Bearing according to claim 3, characterized in that the recesses (14) are regularly spaced and arranged concentrically around the hole (11) of the bearing (10a, 10b). Palier selon l'une des revendications 1 à 4, caractérisé en ce qu'il est réalisé en un matériau monocristallin choisi dans le groupe formé par le rubis, le corindon, le spinelle ou la zircone cubique, l'évidement (14) étant usiné par ablation au moyen d'un faisceau laser, par électroérosion ou par meulage.Bearing according to one of claims 1 to 4, characterized in that it is made of a monocrystalline material selected from the group consisting of ruby, corundum, spinel or cubic zirconia, the recess (14) being machined by laser ablation, EDM or grinding. Palier selon l'une des revendications 1 à 4, caractérisé en ce qu'il est réalisé en un matériau fritté choisi dans le groupe formé par le corindon fritté, le rubis fritté, les céramiques frittées, l'alumine frittée, la zircone frittée ou un métal dur fritté, l'évidement (14) étant réalisé par matriçage ou usiné par ablation.Bearing according to one of claims 1 to 4, characterized in that it is made of a sintered material selected from the group consisting of sintered corundum, sintered ruby, sintered ceramics, sintered alumina, sintered zirconia or a sintered hard metal, the recess (14) being made by stamping or machined by ablation.
EP17157667.1A 2016-12-23 2017-02-23 Low-friction shaft support bearing Withdrawn EP3367182A1 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
EP17157667.1A EP3367182A1 (en) 2017-02-23 2017-02-23 Low-friction shaft support bearing
EP17808805.0A EP3519902B1 (en) 2016-12-23 2017-11-15 Low-friction shaft support bearing
CN201780079616.4A CN110114731B (en) 2016-12-23 2017-11-15 Shaft support bearing with reduced friction
PCT/EP2017/079302 WO2018114149A1 (en) 2016-12-23 2017-11-15 Reduced-friction shaft support bearing
US16/344,237 US11036186B2 (en) 2016-12-23 2017-11-15 Reduced-friction shaft support bearing
JP2019524233A JP6901558B2 (en) 2016-12-23 2017-11-15 Shaft support bearing with reduced friction
KR1020197012887A KR102234880B1 (en) 2016-12-23 2017-11-15 Shaft support bearing with reduced friction
TW106141127A TWI786075B (en) 2016-12-23 2017-11-27 Reduced-friction staff support bearing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP17157667.1A EP3367182A1 (en) 2017-02-23 2017-02-23 Low-friction shaft support bearing

Publications (1)

Publication Number Publication Date
EP3367182A1 true EP3367182A1 (en) 2018-08-29

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EP17157667.1A Withdrawn EP3367182A1 (en) 2016-12-23 2017-02-23 Low-friction shaft support bearing

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EP (1) EP3367182A1 (en)

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CH311285A (en) * 1953-11-28 1955-11-30 Reinhard Dr Straumann Process for the production of a shaft with unbreakable bearing journals for clockworks and precision mechanical apparatus and a shaft with unbreakable bearing journals produced by this process.
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EP3770698A1 (en) * 2019-07-26 2021-01-27 Comadur S.A. Monocrystalline type mineral stone provided with a pivot recentring cone, and method for manufacturing same
EP3770699A1 (en) * 2019-07-26 2021-01-27 Comadur S.A. Stone, particularly for clock movement, and method for manufacturing same
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