Elastic joint.

Abstract

An elastic coupling includes two sleeves (1a, 1b) coupled to respective shafts (E1, E2), and a hole (12) aligned with a cylindrical recess (13) for receiving a metal bearing (3) attached to a bolt (21) of a metal body (2) disposed between the sleeves (1a, 1b). The metal bearing (3) includes an annular metal portion (31) whose outer surface contacts the inner surface of the corresponding recess (13) of one of the sleeves (1a, 1b), an inner metal wire cushion (33) forming a contact surface with the corresponding bolt (21) of the metal body (2) of the metal bearing (3), and side metal wire cushions (34) protruding from both ends of the annular metal portion (31) and forming contact surfaces with the metal body (2) of the metal bearing (3) and the opposing surfaces of the corresponding sleeves (1a, 1b).

Description

[Technical Field]

[0001] The present invention relates to an elastic coupling (also called an elastic joint) applicable to a mechanical transmission for connecting two shafts and transmitting torque from one shaft to the other. [Background technology]

[0002] Different types of elastic couplings are currently known to connect two shafts and provide a joint that is elastic and capable of transmitting torque from one shaft to another and absorbing slight deformations.

[0003] These joints have different structures and configurations depending on the type and degree of deformation to be absorbed, which requires the joint to have a certain stiffness against each type of deformation, i.e., axial, radial, conical, and torsional.

[0004] Elastic couplings comprising two concentrically arranged cylindrical metal reinforcements and a mass of elastomeric material, usually rubber, compressed between the two reinforcements are known in the prior art.

[0005] The problem with these elastic couplings, which contain a mass of elastomeric material, is that they cannot withstand the high temperatures that occur in the operation of certain machines or transport elements, or that such machines may be exposed to when working in high-temperature areas such as foundries or furnace areas. For example, rubber can withstand temperatures up to 80°C. Another drawback is that rubber generally deteriorates when it comes into contact with acids or chemicals, making it impossible to use it to withstand high loads.

[0006] To solve the above problems, there are certain metal joints available on the market, such as those described in U.S. Pat. No. 2,658,710, in which a cylindrical shock absorber with a central drill is placed on a shaft or support. The problem with these joints is that they are suitable for absorbing stresses only in the axial direction and do not provide adequate damping for radial, oblique, or torsional loads.

[0007] European Patent EP 2077402 (HUTCHINSON, SA) describes a damper (shock absorber) for aerospace structures consisting of an annular chamber with compartments, each of which is filled with a wire mesh metal cushion, completing the device with a damping fluid filling the annular chamber and gaps between the wire mesh. This elastic joint is complex to manufacture due to the incorporation of the damping fluid and the need to incorporate a radial shaft seal or hydraulic seal to prevent fluid leakage over time.

[0008] Additionally, this coupling only has axial elasticity and does not provide adequate angular, torsional, or radial elasticity. In this state of the art document, stiffness is provided by the cushion, while damping is provided by the fluid.

[0009] US 2729442 discloses a joint having a deformable cushion arranged between rotating elements formed by an outer sleeve and a square inner sleeve, between which the deformable cushion is arranged.

[0010] Patent ES 2 686 395 B2 describes an elastic coupling for a holder similar to that of the present invention, which comprises an inner ring mounted on a shaft, an outer ring concentric with the inner ring mounted on a support, and a metal wire cushion arranged between an intermediate segment of the inner ring, the intermediate segment of the inner ring, reduced sections towards the opposite ends of the inner ring, and reduced sections towards the opposite ends of the outer ring, and a metal wire cushion arranged between the intermediate segment of the inner ring. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] US 2658710 [Patent Document 2] EP 2077402 [Patent Document 3] US 2729442 [Patent Document 4] ES 2686395 B2 Summary of the Invention [Means for solving the problem]

[0012] According to the invention, the elastic coupling comprises: - two substantially parallel sleeves having: an outer surface provided with means for fixing the respective shafts to be coupled; a series of opposing holes distributed in an annular pattern; an inner surface facing the opposing sleeve; with cylindrical recesses aligned with the respective holes; - a metal body disposed between said sleeves, substantially parallel to said sleeves, and having two opposing faces, each of said faces carrying a series of bolts aligned with the recesses and holes in the respective sleeves; - Metal bearings attached to the bolts of the metal body and housed in respective recesses in the sleeve.

[0013] The bearing (3) is an annular metal part (31) having an outer surface contacting the inner surface of the corresponding recess (13) of one of the sleeves (1a, 1b); and, mounted on said annular metal part: * an inner metal wire cushion (33) that forms the contact surface of the corresponding bolt (21) and bearing (3); and * Side metal wire cushions (34) protruding from both ends of the metal part (31) and forming the contact surfaces of the metal bearing (3) with the metal body (2) and the opposing surfaces of the corresponding sleeves (1a, 1b) and, so that the set of metal bearings (3) provides torsional, radial, axial, and conical stiffness to the elastic coupling.

[0014] The assembly of the different parts of the elastic coupling, i.e. the "bearing in the recess of the sleeve" and the "metal bearing and bolt in the hole of the sleeve", is carried out axially, as is the coupling of the shaft which is coupled with the side sleeve having respective hubs for receiving the ends of the corresponding shafts. In a preferred embodiment, each inner cushion of the metal bearing comprises several annular sectors distributed circumferentially and spaced slightly apart from one another in the tangential direction.

[0015] According to the invention, the annular portion of the bearing has an internal "L"-shaped cross-sectional outer peripheral appendage having a radial length shorter than the cross-section of the inner cushion, so that a forming annular sector of said inner cushion protrudes from the outer peripheral appendage towards the inside of the bearing.

[0016] The peripheral appendage defines, in the metal bearing, an annular recess open towards the inside of the bearing in which the peripheral portion of the inner cushion compressed against the inner surface of the corresponding annular part of the bearing is accommodated, and two annular recesses open towards both sides of the bearing in which the end portions of the corresponding side cushions are accommodated.

[0017] According to the described features, this elastic coupling offers a series of additional advantages to those mentioned above: it absorbs and damps irregularities in the torque transmitted from one shaft to another, displaces critical regimes, accommodates misalignments and differences between the shafts, suppresses possible stresses of rigid couplings under the same conditions, allows for a lighter construction with higher tolerances and is therefore more economical, does not contain flammable materials and withstands high temperatures.

[0018] Another notable feature of this joint is that it has no play in contact by means of a wire cushion, so is silent, has low friction and does not require lubrication. [Effects of the Invention]

[0019] The elastic coupling object of the present invention has technical features that offer a series of advantages, among which it is worth mentioning the use of only metal materials, a structure that is very easy to assemble, the incorporation of a metal cushion that provides elasticity in the joint within the bearing, which ensures stable fixation of the metal cushion, allowing for a lighter structure with higher tolerances and therefore more economical, and at the same time achieving the installation of a metal cushion with an elastic coupling part with four possible stiffnesses, namely axial, radial, conical and torsional. [Brief explanation of the drawings]

[0020] To complement the description given and to facilitate an understanding of the characteristics of the invention, the description is accompanied by a set of drawings in which, by way of non-limiting example, the following are represented: [Figure 1] FIG. 1 shows a perspective view of one exemplary embodiment of the elastic coupling of the present invention. [Figure 2] FIG. 2 shows an elevation view of the elastic joint of FIG. [Figure 3] FIG. 3 shows an exploded perspective view of the elastic coupling. [Figure 4] Figure 4 shows an elevation view of the elastic joint cut along the central vertical plane. [Figure 5] FIG. 5 corresponds to enlarged detail "A" of FIG. [Figure 6] 6 and 7 show a perspective view and an elevation view, respectively, of one of the metal bearings of the elastic coupling. [Figure 7] Same as above [Figure 8] FIG. 8 shows a plan view of the metal bearing taken along the horizontal plane BB' referred to in FIG. [Figure 9] FIG. 9 shows an elevation view of the metal bearing cut along the vertical plane CC' referred to in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] The elastic coupling shown in Figures 1 to 4 comprises two equal sleeves (1a, 1b) arranged symmetrically in parallel planes, a metal body (2) arranged between the sleeves, and a metal bearing (3) arranged between the metal body (2) and the sleeves (1a, 1b).

[0022] The sleeves (1a, 1b) are made of metal and have means for forming hubs (11) on their outer surfaces for fastening to the shafts (E1, E2) connected thereto, as shown in FIG.

[0023] Each of the sleeves (1a, 1b) has a number of holes (12) distributed annularly and facing the opposing sleeve (1b, 1a), and on its inner surface has a cylindrical recess (13) concentric with said holes (12) and intended to receive a respective metal bearing (3) inside.

[0024] The metal body (2) in turn has on its opposite surface a number of bolts (21) aligned with the respective recesses (13) and holes (12) of the sleeves (1a, 1b).

[0025] As can be seen in Figures 4 and 5, the metal bearings (3) are attached to the bolts (21) of the metal body (2) and housed in the recesses (13) of the sleeves (1a, 1b).

[0026] As can be seen from Figures 6 to 9, the metal bearing (3) is substantially cylindrical and comprises an annular portion (31), preferably made of steel, having on its inner surface an "L"-shaped cross-sectional peripheral appendage (32).

[0027] The appendage (32) defines an annular cavity that is open towards the inside of the metal bearing (3), in which the peripheral portion of the inner metal wire cushion (33) is housed, in this case formed by several annular sectors (33a, 33b, 33c) that are arranged circumferentially and slightly spaced apart from one another and that protrude from the appendage (32) towards the inside of the metal bearing (3).

[0028] The appendage (32) also defines two annular recesses in the metal bearing (3) that open towards both sides of the metal bearing and receive the ends of the respective side metal wire cushions (34).

[0029] As can be seen in cross section in Figure 4 and in enlarged detail in Figure 5, in the mounting position of the elastic coupling, the metal bearings (3) are mounted on the bolts (21) of the metal body (2) and housed in the recesses (13) of the corresponding sleeves (1a, 1b).

[0030] In this assembled position, the metal bearing (3) contacts the outer surface of the annular portion (31) against the inner surface of the corresponding recess (13), the annular sectors (33a, 33b, 33c) form an inner cushion (33) against the corresponding bolt (21), and the ends of the side cushions (34) contact the metal body (2) and the opposing surfaces of the corresponding sleeves (1a, 1b).

[0031] In this way, the metal body (2) and sleeves (1a, 1b) are kept separated by the inner cushion (33) and the side cushions (34) of the metal bearing (3) which provide a resilient coupling with axial, radial, torsional and conical stiffness.

[0032] Once the nature of the invention and examples of preferred embodiments have been fully described, it is stated for all relevant purposes that the equipment, form, size, and arrangement of the elements described are subject to change without resulting in a change in the essential characteristics of the invention as hereinafter claimed. [Explanation of symbols]

[0033] 1a, 1b: Sleeve 2: Metal body 3: Metal bearings E1, E2: Shaft 11: Hub 12: Hole 13: Cylindrical recess 21: Bolt 31: Circular part 32: "L" shaped cross section peripheral attachment 33: Inner metal wire cushion 33a, 33b, 33c: Annular sector 34: Side metal wire cushion

Claims

1. 1. An elastic coupling suitable for connecting two shafts (E1, E2) and transmitting torque from one shaft to another, comprising: two substantially parallel metal sleeves (1a, 1b); a metal body (2) disposed between the metal sleeves (1a, 1b); a metal bearing (3), The metal sleeves (1a, 1b) have an outer surface provided with fixing means for each of the shafts (E1, E2) to be connected, an inner surface with a number of opposing holes (12) and cylindrical recesses (13) facing the opposite sleeve and aligned with the respective holes (12), The metal body (2) is substantially parallel to the metal sleeves (1a, 1b) and includes, on two opposite sides, a plurality of bolts (21) aligned with respective recesses (13) and holes (12) in the metal sleeves (1a, 1b); The metal bearings (3) are attached to the bolts (21) of the metal body (2) and housed in the recesses (13) of the metal sleeves (1a, 1b), Here, the metal bearing (3) includes an annular metal portion (31), the annular metal portion (31) contacts with the inner surface of the corresponding recess (13) of one of the metal sleeves (1a, 1b) an outer surface of the annular metal portion (31); An inner metal wire cushion (33) and a side metal wire cushion (34) are installed in the annular metal portion (31), The inner metal wire cushion (33) forms a contact surface between the corresponding bolt (21) of the metal body (2) and the metal bearing (3); The side metal wire cushions (34) protrude from both ends of the annular metal portion (31) and form contact surfaces of the metal bearing (3) with the metal body (2) and the corresponding opposing surfaces of the metal sleeves (1a, 1b); As a result, the metal bearing (3) provides a resilient coupling with torsional, radial, axial and conical stiffness.

2. 2. The elastic coupling according to claim 1, characterized in that the inner metal wire cushion (33) comprises a plurality of annular sectors (33a, 33b, 33c) arranged circumferentially and spaced slightly apart from one another in the tangential direction.

3. The annular metal portion (31) of the metal bearing (3) includes an "L"-shaped cross-sectional outer peripheral appendage (32) therein, The cross-sectional outer peripheral appendage (32) has a length in the radial direction that is shorter than the cross section of the inner metal wire cushion (33), 3. The elastic coupling according to claim 1 or 2, characterized in that the cross-sectional outer peripheral appendage (32) has an annular recess that opens toward the inside of the metal bearing (3) and receives the peripheral edge portions (33a, 33b) of the inner metal wire cushion (33), and two annular recesses that open toward both sides (also called opposite sides) of the metal bearing (3) and receive the ends of the corresponding side cushions (34).

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