FR2523678A1 - ELASTOMER INSULATION BEARING AGAINST VIBRATION - Google Patents

Abstract

THE INVENTION RELATES TO AN ISOLATION BEARING AGAINST VIBRATIONS. ACCORDING TO THE INVENTION, IT INCLUDES TWO OPPOSED AND SPACED EXTREME FLANGES 12, 14, A LAMINATION 16 OF ALTERNATE ELASTOMERIC LAYERS 18 AND SENSITIVELY NON-EXTENSIBLE 20 GLUED TO ONE ANOTHER BETWEEN THE FLANGES, A STABILIZING MEANS 22 PROVIDED BETWEEN THE FLANGES AND CONNECTING THEM, THE MEANS OF STABILIZATION INCLUDING AT LEAST ONE COLUMN HAVING ONE END FIXED SOLIDLY TO A FIRST OF THE FLANGES AND A SECOND END FIXED SOLIDLY TO THE OTHER. THE INVENTION APPLIES IN PARTICULAR TO THE STABILIZATION OF ROBOTS.

Description

The present invention relates to isolation stages against

  vibration and more particularly to laminated bearings having better column stability and better able to account for tensile loads.

  Robotics is a field whose technological advance

  logic is explosive Many advances relate to robot tongs and manipulators that can be considered the equivalent of the human hand The tongs

  derobot are used for a wide variety of applications.

  including, for example, various holding and holding functions. The robotic hands and handles which

  exist use a remote flexible central device.

  To take account of a parallel and angular misalignment in such a device, between the clamps and the end of the robot arm, the industry has turned to a number of devices such as that shown in the patent No. 4,098,001. In this patent, two end plates are connected in parallel by a number of metal wires. This arrangement makes it possible to take account of the traction forces and the misalignment that can be seen in a typical robotic application. The arrangement taught in this patent has a disadvantage because the connecting wires tend to vibrate after each load-unload cycle and thus inhibit the support performance if they are immediately recharged. It is therefore necessary in such an arrangement for time between successive charges to allow the bearing to return to steady state. the layout tends

  to warp under a compressive load.

  Vibration isolators are known in the art which are constructed in the form of a sandwich or laminate composed of alternating layers of elastomer and a non-stretchable material. Typically, the non-stretchable material is in the form of wedges. elastomer layers are bonded together Laminating is typically located between parallel and opposite flat end plates. Such a vibration isolator can easily withstand a compressive load. However, such an insulator may be susceptible to warping and its ability to of support for a tensile load is limited as described in

  U.S. Patent No. 3,292,711 of December 20, 1966, the left-handed

  In particular, a laminated vibration isolator occurs when the ratio of height to width is relatively large. The elastomer in the center tends to compress outwardly from between the end plates, so the outline of the outer surface parallel to the load will take a general shape of "C" (The location of the extreme dislodgement of the rubber is typically a point between the end plates radially furthest from the central axis of the lamination, said axis being perpendicular to the planes where the layers of the laminate are placed) This effect can be considered as if the elastomer and the shims in the center of the column were compressed outwards by unbalanced bulge forces due to the compressive load. the compression load is applied along the axis of the assembly, forces at right angles to the axis of the assembly develop; an imbalance of these forces causes movement of the elastomer at right angles to the axis of the insulator. When the elastomer moves laterally with respect to the axis, its load bearing capacity decreases rapidly and it is not Typically more suitable for supporting the large compressive loads it is often asked for. A wide variety of designs have been disclosed in the above-identified patent to retain the warping of the insulator. However, these designs do not simultaneously provide the capacitance. tensile load support and to take account of the misalignments that are desired, for example, in

  derobotic applications described above.

  The present invention therefore has as its object

  a bearing having better column stability.

  Another object of the present invention is a laminated bearing for receiving a compressive load.

  and able to resist warping of the column.

  Another object of the present invention is a bearing capable of supporting sensitive compressive and tensile loads while providing better stability of

the column.

  Another object of the present invention is an isolation bearing against vibrations which can take into account a compressive load with better stability.

of the column.

  These and other objects of the invention are achieved by providing a vibration isolation bearing which comprises a lamination of alternating elastomeric and non-extensible layers which are bonded to each other between spaced-apart and end-facing end flanges. Between these end flanges is connected to them and fixed at least one wire of linear configuration when the insulator is discharged and which extends substantially perpendicular to the planes o are arranged the layers of the lamination Preferably, the wire is made in one substantially non-stretchable material, such as for example thermally treated steel Furthermore, the layers of the lamination may each be provided

  a hole placed centrally or bore filled with elasto-

  mother o is disposed the wire The laminating can be either molded after assembling the wire with the flanges or it can be formed separately and drilled to allow the assembly of wire and flanges Under the load, tensile loads are substantially supported by the wire while the compressive loads are substantially supported by the elastomer lamination and the wire in parallel The warping is restricted by the combination of the features and in particular by the fact that the wire is attached to the flanges and can not be warp because of the provision of

  the elastomer in the central zone of the lamination.

  According to another embodiment of the invention designed for applications where the support capacity of a tensile load is not required while the stability of the column is sought, the wire

  should not necessarily extend continuously

  However, the metal wire may be attached to one of the non-extensible layers or shims in the lamination. Alternatively, two collinear metal wires may be employed, each extending from an associated flange to which it is connected. to the other wire, with a space substantially filled with elastomer between them According to another embodiment of the invention, the wire may be attached to a flange at each of its ends and may be further attached to one or In another embodiment of the invention, a lamination is modified to have each of its layers configured non-planar, for example, a cone or sphere configuration truncated with the flanges contoured to correspond to this arrangement of the lamination makes it possible to better take into account the torsiontout

  resistant to shear and warping.

  The invention will be better understood, and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatory text which will follow with reference to the accompanying schematic drawings given solely by way of example illustrating several embodiments of the invention and in which: FIG. 1 is a side elevational view, partly broken away, of a bearing of isolation against vibrations illustrating an embodiment of the invention; and Figures 2 to 6 each show a side elevation partially broken away from other modes.

embodiment of the invention.

  Referring to the drawings and more particularly to Figure 1, it can be seen that the vibration isolation bearing 10 as illustrated comprises opposed members or flanges 12 and 14 with an elastomeric lamination 16 comprising layers alternating 18 and 20 respectively of elastomeric material and a material

  substantially non-expandable (shims) and a means of stabilizing

  The stabilizing means 21 is illustrated as a thin column or wire 22 which is embedded in the elastomeric material and which is disposed between the two flanges 12 and 14 which it connects by its ends.

  24 and 26 respectively.

  As can be seen, each of the flanges 12 and 14 is in the form of a straight and solid circular cylinder. The flanges 12 and 14 comprise spaced apart and facing end surfaces 28 and 30, secondary or exposed surfaces 32 and 34 which are parallel to the extreme surfaces

  28 and 30, and cylindrical surfaces 36 and 38, respectively

  Similarly, means of securing or securing

  40 may be provided on each flange 12 or 14 for each

  attach each to structures or elements (not

  The wire 22 is securely attached to the flanges 12 and 14 with the ends 24 and 26 of the wire which are preferably in threaded engagement with the end surfaces 28 and 30, respectively. and 26 of the wire can also be attached to the flanges 12 and 14 by other techniques, for example by welding what can produce

  uncordon 42, as shown in FIGS. 2, 4, 5 and 6.

  It should be noted, however, that accordion 42 is not a part of

essential of the invention.

  The column or wire 22 has the shape of a linear or straight configuration when the bearing 10 is in a discharged condition. The wire 22 must be of a substantially rigid material, although flexible, and it is preferably made of steel. a heat-treated steel such as maraging 250 stainless steel has proved particularly suitable because of the ease of its preparation for bonding; as another example, the metallic EL may be constructed of a fiberglass material which has the virtue of being substantially non-conducting.

  preferably a small diameter of the order of 0.157 cm.

  The lamination 16 comprises a number of shims 20 which are preferably made of metal and, as can be seen in this figure, which have a general configuration of a ring or washer with an internal bore or opening 44 defined and an outer radius for example, approximately equal to the radius of the lamination 16 which preferably (but not necessarily) is of cylindrical configuration The shims 20 are axially spaced parallel to each other and are concentric with the longitudinal axis of the bearing 10 and him

  are perpendicular In a preferred method of manufacturing

  In one embodiment, the elastomeric layers 18 comprise a rubber material which is molded around the wedges 20 and the wire 22 after orienting and aligning them in the assembly as shown. The elastomer material is thus bonded to each of the wedges. 20 and the end surfaces 28 and 30 The elastomer also has the shape of a circular cylindrical tube and straight or "heart" in the opening 44 defined by the shim 20 and around the wire 22 to which it is glued Alternatively, the lamination 16 may be preformed, for example, with a solid core 46 to be drilled to allow insertion of the wire therethrough, followed by assembly of the wire and lamination between the wires.

  flanges 12 and 14 and connection thereto.

  The lamination 16 in this embodiment is glued or otherwise attached to the flanges 12 and 14 by an agent

sticky or junction.

  FIG. 2 shows another embodiment of the invention. As can be seen, the bearing 10 A is similar to that illustrated in FIG. 1 with the exception of the stabilizing means 21. In FIG. 2, the means for producing a warping retainer comprises two metal columns or wires 52 and 54 having first ends 56 and 58 respectively attached to flanges 12 and 14, their other ends 60 and 62 respectively being disposed in spaced relation and face to face The two wires 52 and 54 are thus arranged collinearly relative to each other and perpendicular to the plane in which the shims 20 and the end surfaces 28 and 30 are arranged when the bearing 10 A is not loaded in compression between the opposite ends 56 and 58 is placed an elastomeric material integral with the elastomer of the tube 46 (see FIG. 1) and preferably being integral with the elastomer layers 18 of embodiment provides better warp stability compared to a

  laminated bearing not employing the present invention.

  Furthermore, this bearing 10 A can withstand a compressive load but it is not designed to withstand a voltage and therefore it has the same limits with regard to the loading as the laminated bearings according to the prior art However, it has advantages over the embodiment of FIG.

  makes it more economical and easier to manufacture.

  FIG. 3 shows another embodiment of the invention where the bearing 10 B comprises a fixing means 21 which comprises a wire 68 arranged perpendicularly to and spaced from the end faces 28 and 30. The wire 68 is connected to an extended shim or plate 70 which is similar to the other shims 20 except that it does not have the central opening designed for the other shims 20 at 44 The plate 70 is orthogonally disposed with respect to the wire 68 and is preferably connected (for example by welding the wire 68 into a small hole (not shown) of the plate 70 or by welding two collinear halves of the wire of each

  side of the plate) at wire 68 approximately at its midpoint.

  Such junction by the midpoint allows symmetry along the axial extent of the column, and provides support

  against warping at its midpoint of inflection.

  This is particularly effective in improving the stability

  However, the embodiment of FIG. 3, like that of FIG. 2, is not designed to support tensile tensile loads. The theory on which this is based is explained in the book. Strength of Materials "by Ferdinand L Singer, published by Harpers and Brothers,

  New York, United States of America, pages 352 to 354.

  In the bearing 10 B, the lamination 71 is formed in a manner similar to the lamination 16 of FIG.

  the exception that the plate 70 replaces one of the shims 20.

  Alternatively, the lamination 16 B can consist of two sub-fillings 72 and 74 each integrally molded with an associated flange 12 or 14 and which is glued to it, or else separately molded and fixed by a tackifier. Similarly, the sub-foliations 72 and 74 can be molded by being separated from the plate 70 and be

  fixed on opposite sides with an alternating

  Finally, one of the sub-folios 72 or 74 may be

  molded directly onto the plate 70 and the other

  laminating 72 or 74 can then be attached with an agent

  sticky or cemented to the other flat side of the plate 70.

  FIG. 4 shows another embodiment of the invention representing the bearing C 0 the stabilizing means 21 as in FIG. 1 is a wire 22 whose ends 24 and 26 are connected to the end surfaces 28 and 30 respectively However, in contrary

  in FIG. 1, in this embodiment the metal wire

  22 is also connected to the shim 70 in the manner described above for FIG. 3. This embodiment therefore makes it possible to obtain a better retention of the warping at the midpoint while allowing to withstand sensitive compressive loads as well as

traction.

  FIG. 5 shows a bearing 1 OD which represents a variant of the embodiment of FIG. 4 In the bearing 10 D, two plates 75 and 76 are incorporated, each having a configuration similar to the plate 70 of FIG. 3 or 4 and each being disposed in a plane orthogonal to the wire 22 and connected thereto as described above. The two plates 75 and 76 are spaced apart to form a three-point surround, i.e. they are connected to the wire 22 along its length at two of its points of inflection It will be understood that the points of inflection correspond to the

  points where the bending moment is substantially zero.

  As can be seen, one or more shims 20 are disposed between the flange 12 or 14 and the plate 75 or 76 which is closest thereto, as well as between the two plates and 76 The lamination 77 can be formed in one piece or include sub-folios 78, 79 and 80 of a

  similar to what has been described for Figure 3.

  FIG. 6 shows another embodiment of the invention where the bearing 10 E comprises the lamination 81 which comprises a number of frustoconical layers 82 and 84 corresponding, in material, to the layers 18 and 20 of the lamination 16 of FIG. and which are arranged in a similar manner Each flange 86 and 88 has end surfaces or faces 90 and 92 which are not flat but rather concave and convex respectively in order to be in intimate contact with the lamination 81 Alternatively, it will be understood that the layers 82 and 84 and the end faces 90 and 92 may have a truncated sphere configuration. Moreover, it will be easily understood that a midpoint surround, a three point surround, multiple metallic or linear wires or a non-metallic wire. connected to the flanges can be incorporated

  alternatively or in combination in this configuration.

  This configuration provides yet another gain in column stability while also providing better shear retention. Thus, it can accommodate torsion while resisting shear and warpage. It is apparent that the invention described here can

  to be put into practice otherwise than as illustrated.

  For example, any number of enclosures per point, in combination with any method of attachment of the ends

  wire son are part of the scope of the invention.

  Furthermore, the flanges and the lamination need not necessarily have a cylindrical configuration but may rather have any shape, for example of rectangular or square cross section Moreover, a number of parallel metal son extending through the core of the lamination may be used with any combination for each midpoint or extreme attachment method described herein. Another bearing arrangement includes a lamination as herein described with a number of wires connecting the flanges, the wires being disposed therein.

  radially outward and around the bearing.

he

Claims (20)

R E V E N D I C A T I 0 N S   1._ Vibration isolation bearing, characterized in that it comprises two spaced and opposite end flanges (12, 14), a lamination (16) of alternating layers of an elastomeric material (18) and substantially non-extensible (20) interconnected between the flanges, and a stabilizing means (22) disposed between said flanges and connecting them, said stabilizing means comprising at least one column having an end securely attached to a first one of said flanges and a second end firmly attached to the other said flanges.   Bearing according to Claim 1, characterized in that the column is substantially linear when the bearing is not loaded in compression and is   embedded in the elastomer within said lamination.   3. Bearing according to claim 1, characterized in that each of the non-extensible material layers is annular, defining an opening (44), the column being a wire disposed in said opening and an elastomeric material being disposed around said column and forming part of the elastomeric material in said elastomeric layers.   4. Bearing according to claim 3, characterized in that the aforementioned column is a metal wire substantially unstretchable.   5. A method of manufacturing a vibration isolation bearing, characterized in that it consists in securely attaching an end of a wire to a first flange; to secure a second end securely   said wire to a second flange; to arrange the-   said flanges at a distance from each other which is equal to the length of the wire; forming a laminate of alternately elastomeric and substantially non-extensible layers comprising aligning the apertures disposed in said non-extensible layers, and molding the elastomer between said non-extensible layers as well as in said openings and arranging the yarn metallic in   aligned openings of the non-extensible layers.   A method according to claim 5, characterized in that said shaping step comprises forming the lamination into a unit and further drilling a bore through the elastomer into said aligned holes sized to receive the yarn metallic,   and placing said wire in said bore.   7. The method of claim 5, characterized in that it further comprises arranging the non-extensible layers in parallel relationship and spaced relative to each other, one of the flanges at each end having the wire perpendicular to the holds and in their aligned holes, and molding the elastomer between said wedges, and between said wedges and said wire   metal, and between said wedges and said flanges.   8. Isolation bearing against vibration, characterized in that it comprises two opposite flanges; a lamination comprising alternating elastomer layers and a substantially non-extensible material, said lamination being disposed between said flanges; and a stabilizing means disposed in the lamination and embedded in the elastomeric material comprising a wire connected to at least one of said layers not extensible.   Bearing according to Claim 8, characterized in that the wire is separated from the flanges by the elastomer.   10. Bearing according to claim 8, characterized in that the wire is connected to at least one of the above non-extensible layers and is connected to   each of its ends, to one of the aforementioned flanges.   11 Bearing isolation against vibration, characterized in that it comprises two opposite flanges, a lamination of alternating layers of rubber and shims and two metal son, each having a first end connected to one of said flanges, said son metal being collinear and having their seconds   ends separated by rubber.   Bearing according to one of Claims 1, 8 or 11, characterized in that the lamination   aforementioned comprises frustoconical layers.   13. Bearing according to any one of   1, 8 or 11, characterized in that the   aforesaid lamination includes layers In truncated sphere.   14. Bearing according to any one of   Claims 3 or 9, characterized in that the elastomer is glued to the wire.   15. Isolation bearing against vibration, characterized in that it comprises: two opposite flanges; a laminate disposed between and bonded to said flanges, which comprises at least two stacked sub-fillings, each of said sub-laminates comprising a number of alternating layers of elastomer and substantially non-extensible layers, said non-extensible layers being traversed by at least one opening, said sub-foliations having between them a shim; and column stabilizing means disposed in said openings in said non-extensible layers so as to   orthogonal to them, said stabilizing means   being connected securely to said plate.   16. Bearing according to claim 15, characterized in that the aforementioned stabilizing means is a column connected firmly to one of its ends, at one of the aforementioned flanges.   17. Bearing according to claim 15, characterized in that the aforementioned lamination comprises a first sublayer disposed between one of said flanges and a first shim and which is bonded thereto, a second lamination disposed between the other of said flanges. and a second shim and which is glued thereto, and a third lamination disposed between said first and second shims; and in that the first and second wedges are   secured to the stabilizing means.   18. Bearing according to any one of   claims 15 or 17, characterized in that the means   stabilization is a column embedded in the elastomer   forming part of the elastomer layers.   19. Bearing according to claim 18, characterized in that the column is fixed at each of its ends, to one of the aforementioned flanges.   Bearing according to Claim 18, characterized in that the aforementioned column extends at each of its ends towards one of the flanges, although it is spaced apart.