EP4301997A1

EP4301997A1 - Vibration damping device

Info

Publication number: EP4301997A1
Application number: EP22708629.5A
Authority: EP
Inventors: Simone Cinquemani; Antonino LO FORTE
Original assignee: Politecnico di Milano
Current assignee: Politecnico di Milano
Priority date: 2021-03-05
Filing date: 2022-03-04
Publication date: 2024-01-10
Also published as: WO2022185273A1; IT202100005237A1

Abstract

A damping device (1) is disclosed to be fitted to an apparatus whose vibrations are to be damped, comprising a first (2) and a second (3) connecting element, to be connected respectively to a first (10) and to a second (11) part of the apparatus and which are relatively movable during operation of the apparatus itself, a deformable dissipating element (4), interposed between the first (2) and the second (3) connecting element, and having a contact surface configured to slidingly couple with a sliding surface of the first (2) or of the second (3) connecting element to contrast, by exerting a friction action, the relative movement between the two connecting elements; it is possible to modify the relative angular position of the contact and sliding surfaces so as to adjust the corresponding degree of mutual contact and consequently the degree of dissipation of the vibrations through the effect of the friction.

Description

VIBRATION DAMPING DEVICE

Context of the invention

[0001] The invention relates to a vibration damping device to be inserted into vibrating systems or apparatuses whose vibrations are to be damped, in particular a vibration damping device that enables a variable damping force to be applied in a desired manner.

Prior art

[0002] Vibration damping devices to be inserted into household appliances, for example washing machines, that require their presence are known.

[0003] Such vibration damping devices generally comprise telescopic tubular elements anchored by a respective end to two parts of a vibrating apparatus that are relatively movable during one or more operating steps of the apparatus. These devices have a dissipating element interposed between the two tubular elements, intended to exert a dissipating friction force in situations in which corresponding motion between the telescopic tubular elements during the operation of the apparatus to which such damping devices are fitted occurs.

[0004] Vibration damping devices of active type are in particular known, i.e. vibration damping devices in which it is possible to activate or deactivate the damping action by drawing energy from an external source. For example, vibration damping devices are known that are provided with a piezoelectric body that, powered by an external source of energy, regulates the activation or deactivation of a dissipating element assigned to damping vibrations.

[0005] Vibration damping devices are further known the vibration damping action of different frequency of which is achieved by means of dissipating structural elements made of particular shape memory metal alloys. [0006] Vibration damping devices like those just described, for example vibration damping devices like those disclosed in documents KR101286703 B1 or US2006011429 B2, have some drawbacks. Such damping devices, in addition to not being sufficiently easy to manage functionally, are also structurally complex, because of the very high number of mechanical and/or electronic components suitable for obtaining the damping effect. In addition, using the aforesaid components makes such known vibration damping devices particularly expensive.

[0007] EP1277984 discloses a device for the damping of movement between two cylindrical pieces sliding one on the other in translation and frictional engagement. [0008] In the light of what has been set out above, there is accordingly ample room for improvement of current damping devices.

Objects of the invention

[0009] One object of the invention is to improve current damping devices. [0010] Another object of the invention is to provide a damping device that is an alternative to known devices and is able to effectively damp the vibrations of an apparatus. [0011] Another object of the invention is to provide a structurally simpler damping device that is consequently more reliable and cheaper than already existing damping devices but is at the same time advantageous from the functional point of view. [0012] A still further object of the invention is to provide a damping device that enables the friction action to be regulated simply that is exerted on the basis of the degree of damping of the vibrations that it is desired to obtain on the apparatus in question.

[0013] These objects and still others are achieved by a damping device as disclosed in one or more of the claims set out below. Short description of the invention

[0014] According to the invention, a vibration damping device is provided as defined in the attached claims.

[0015] In particular, the present damping device is suitable for being inserted into apparatuses whose vibrations are to be damped, for example household appliances like a washing machine.

[0016] The damping device according to the invention comprises two connecting elements, respectively connected to a first and to a second part of an apparatus whose vibrations are to be damped, which are relatively movable during the operation of said apparatus. [0017] The vibration damping device according to the invention further comprises a deformable element interposed between the two connecting elements and having a contact surface configured to slidingly couple with a sliding surface of the first or of the second connecting element.

[0018] The insertion of the deformable element between the two connecting elements allows to contrast the relative movement between the first and second connecting element during operation of the apparatus whose vibrations are to be damped owing to the effect of a friction force.

[0019] Said friction force is exerted between a sliding surface of the deformable element and a contact surface of the first or of the second connecting element, depending on the embodiment, said sliding surface and said contact surface being slidingly coupled.

[0020] According to the invention, the friction force between said sliding surface and said contact surface is easily modulable owing to the fact that the two sliding and contact surfaces are mutually rotatable and geometrically configured to couple with a mechanical interference that is variable according to an angular position of one with respect to the another. In this manner, the vibration damping device enables the degree of dissipation through the effect of the friction linked to the degree of mutual contact between the two surfaces to be adjusted.

Short description of the drawings

[0021] The invention can be better understood and implemented with reference to the attached drawings that illustrate some non-limiting embodiments thereof, in which:

Figure 1 is an exploded perspective view of a damping device according to the invention; Figure 2 is a frontal view of the damping device of Figure 1 according to the invention; Figure 3 is a longitudinal section view of the damping device taken along the plane III-III in Figure 2;

Figure 4 is another longitudinal section view of the damping device according to the invention, identical to the one shown in Figure 3;

Figures 5, 5A are cross section views of the geometric profiles of the connecting and dissipating elements and of a closing element comprised in the damping device taken along the plane V-V in Figure 4;

Figure 6 is another longitudinal section view of the damping device according to the invention;

Figure 7 is a cross section view, taken along the plane VII- VII in Figure 7, that shows the geometric profiles of the connecting and dissipating elements in non-interacting configuration, comprised in the damping device;

Figure 8 is a longitudinal section view of the damping device according to the invention; Figure 9 is a cross section view, taken along the plane IX-IX in Figure 8, that shows the geometric profiles of the connecting and dissipating elements in interacting configuration, comprised in the damping device of Figure 8;

Figures 10A, 10B, IOC, 10D schematically show the geometric profiles of the dissipating element and of the connecting element through which a damping friction force is applied; Figure 11 is an enlarged longitudinal section view of the first embodiment illustrated in Figure 1;

Figure 12 is an enlarged longitudinal section view of a second embodiment of the damping device according to the invention;

Figure 13 is an enlarged longitudinal section view of a third embodiment of the device according to the invention;

Figure 14 is an enlarged longitudinal section view of a fourth embodiment of the device according to the invention.

Detailed description of the invention

[0022] With reference to the Figures mentioned above, it is pointed out that for the sake of simple exposition; identical elements of different embodiments have been indicated with the same reference number.

[0023] With 1, a vibration damping device is indicated that is suitable for being fitted in an apparatus whose vibrations are to be damped.

[0024] As will be disclosed in greater detail below, the damping device 1 is configured to damp the vibrations of a running electromechanical apparatus, for example a household appliance, or of any other apparatus in which there are mechanical parts which are movable in relation to one another and the relative movement of which it is desired to attenuate. The vibrations are damped by the damping device 1 through the effect of the application of a friction force between a contact surface and a sliding surface of two elements comprised in said damping device. The damping device 1 according to the invention further enables said friction force to be modulated simply by varying appropriately the degree of overlap between the aforesaid contact and sliding surfaces. [0025] The damping device 1 according to the invention comprises two connecting elements suitable for being connected to two parts of the apparatus whose vibrations are to be damped. More in particular, the damping device 1 comprises a first connecting element 2, suitable for being connected to a first part 10 of the apparatus, and a second connecting element 3, suitable for being connected to a second part 11 of the apparatus.

[0026] The aforesaid first connecting element 2 and second connecting element 3 are configured to be relatively movable in translation along a longitudinal geometric axis X. The relative translating movement between the aforesaid first 2 and second 3 connecting elements occurs, in particular, during operation of said apparatus i.e. due to the relative movement of the two parts 10 and 11 of the apparatus to which the second 3 and the first 2 connecting elements are respectively connected. [0027] The aforesaid first connecting element 2 and second connecting element 3 are also configured to be mutually rotatable around the aforesaid longitudinal axis X during operation of the apparatus. As will be disclosed further on, the relative angular position between the first connecting element 2 and the second connecting element 3 can be varied, owing to the action of a suitable member, to modulate the damping force of the damping device 1 according to the invention.

[0028] In a first embodiment of the damping device 1, the first connecting element 2 and the second connecting element 3 are shaped as two telescopic tubular elements, i.e. are inserted into one another and are able to move transversely and rotate reciprocally with respect to said longitudinal axis X. For example, the two connecting elements 2 and 3 can translate reciprocally along the aforesaid longitudinal geometric axis X when the apparatus to which they are connected is operating, because the first part 10 and the second part 11 of said apparatus can, in turn, be subjected to reciprocal moving towards or moving away movements when the apparatus itself is operating. [0029] With particular reference to Figure 3, the first connecting element 2 is a tubular element having an inner cavity 5 that extends longitudinally according to the longitudinal geometric axis X.

[0030] The first connecting element 2 has a protrusion 6, at a first end, on which a hole 12 is obtained that enables said first connecting element 2 to be connected to the second part 11 of the apparatus by anchoring means that is not shown. The hole 12 can be, for example, circular.

[0031] The second connecting element 3 is an oblong element that extends along the longitudinal geometric axis X, and it is configured to be received in the inner cavity 5 of the first connecting element 2. [0032] The second connecting element 3 has a protrusion 13 that projects from one end thereof, and it has a smaller cross section than the rest of the body.

[0033] The first connecting element 2 and the second connecting element 3 are made of vibration resistant material, for example plastics or metals.

[0034] The damping device 1 according to the invention further comprises a deformable dissipating element 4, interposed between the first connecting element 2 and the second connecting element 3.

[0035] As best visible in Figures 11-14, the deformable dissipating element 4 has a contact surface 7 shaped to couple slidingly with a sliding surface 8 of said first connecting element 2 or with a sliding surface 9 of said second connecting element 3.

[0036] More in particular, in a first embodiment shown in Figure 3 and in the enlarged detail of Figure 11, the deformable dissipating element 4 can be shaped as an annular element, inserted in a shape coupling manner onto the protrusion 13 of the second connecting element 3. More in particular, the inner surface 17 of the deformable dissipating element 4 of annular shape can be placed in contact with the outer surface 18 of the protrusion 13 of the second connecting element 3.

[0037] As shown in detail in Figure 11, the deformable dissipating element 4 is fitted to the protrusion 13 and is interposed between a transverse wall 14 of the second connecting element 3 and a bushing 15, which is also of annular shape and inserted in a shape coupling manner onto said protrusion 13. The bushing 15 is inserted in order to maintain the deformable dissipating element 4 stationary in contact with the transverse wall 14 of the second connecting element 3. Nut fixing means 16 is further inserted (visible in Figure 3) that is coupled by screwing to the protrusion 13 in order to tighten the deformable dissipating element 4 to the second connecting element 3 in the configuration that has just been disclosed. In said first embodiment, the deformable dissipating element 4 moves integrally with the second connecting element 3 with which it is coupled.

[0038] The deformable dissipating element 4 is made of elastically deformable material. For example, it can be made of polymeric material, or of felt or of another suitable material. More in particular, the deformable dissipating element 4 can consist of an inner part of the ring made of stiffer material, and of an outer part of the ring made of more yielding material, the separation between the two inner and outer parts being shown in Figures 11-14 by a dashed line.

[0039] The damping device 1 according to the invention further comprises an adjusting member 20 suitable for adjusting the relative angular position between the first connecting element 2 and the second connecting element 3.

[0040] The adjusting member 20 can be of manual type or of electromechanical type or of another type suitable for relative angular regulation between said first 2 and second 3 connecting element, more precisely between the deformable dissipating element 4 and said first 2 or second 3 connecting element, depending on the embodiment.

In the embodiment in which the adjusting member 20 is purely manual, the dissipating force is set by rotating the deformable dissipating element 4 manually with respect to the first 2 or the second 3 connecting element, depending on the embodiment. In particular, in the embodiment in which the adjusting member 20 is purely manual, the dissipating force is set before the operation of the apparatus. For this purpose, more in particular, manual intervention is carried out on a member that enables a rotation of the deformable dissipating element 4 from the outside, such as, for example, a screw member or another suitable member that is not shown in the Figures. In this case, the damping device 1 is a system of completely passive type that for operation does not require to be associated with any source of energy.

In the embodiment in which the adjusting member 20 is of electromechanical type, the dissipating force is set by a source of external energy sending an appropriate electric signal. In this manner, the angular position between the deformable dissipating element 4 and said first 2 or second 3 connecting element is adjusted each time according to the embodiment, so as to apply a damping friction force previously set on the basis of the operating needs. Once the angular position between the aforesaid elements has been set, no further dispensing of energy or sending of an electric signal by the aforesaid source of external energy is necessary. As a result, the action of the adjusting member ceases at the moment in which the damping operating action starts. In this case, the damping device 1 is configured as a system of semi-passive type.

In one embodiment (that is not shown), it is also possible to provide a programmed control unit to automatically set different degrees of dissipating action during operation of the apparatus. For example, in the case of a washer or a dryer, the drum of which is intended to rotate at variable speeds over the course of the operating cycle (spinning, drying, etc.) the control unit intervenes on the adjusting member to adapt the dissipating force in function of the specific operating step of the household appliance.

[0041] In the first embodiment, the adjusting member 20 is connected to the second connecting element 3 by fixing means, indicated by the reference 21 in Figure 1. According to this embodiment, the adjusting member 20 is configured to rotate the second connecting element 3 with respect to the first connecting element 2. More in particular, according to this embodiment, the adjusting member 20 is configured to rotate the deformable dissipating element 4, which is integral with the second connecting element 3, with respect to the first connecting element 2.

[0042] The adjusting member 20 is housed in a box casing 22, open on one side. On the side opposite the opening, the box casing 22 has a protrusion 23 in which a hole 24 is obtained by means of which the second connecting element 3 is connected to the first part 10 of the apparatus, whose vibrations are to be damped. The hole 24 can be, for example, circular.

[0043] The open side of the box casing 22 is closed by interposing a support plate 25. A closing element 26 is placed to abut on a closing element 26. Said closing element 26 has a T-shaped longitudinal profile with a central part of tubular type inside which the second connecting element 3 is inserted. The closing element 26 has also a ribbing 29 that extends longitudinally on the external surface thereof. Said ribbing 29 is suitable for engaging in in a shape coupling manner with a groove 19 (as visible from the profiles shown in Figures 5 and 5A) obtained longitudinally in the inner surface of the first connecting element 2. Coupling between the ribbing 29 and the groove 19 is carried out in order to prevent a rotation between the first 2 and the second 3 connecting element during operation of the apparatus to which the damping device 1 is fitted. More in particular, coupling between the ribbing 29 and the groove 19 ensures maintenance of calibration or setting, once the angular position of the deformable dissipating element 4 is established, which is integral with the second connecting element 3, with respect to the first connecting element 2. In an alternative embodiment, the ribbing 29 can be obtained on the inner surface of the first connecting element 2, and the groove 19 can be obtained on the outer surface of the closing element. Said closing element 26, support plate 25 and box casing 22 are locked together by fixing means 27, 28 of nut-bolt type. [0044] As previously mentioned, the damping device 1 according to the invention enables to damp the vibrations of the apparatus to which it is fitted thanks to the application of a friction force between a contact surface of the deformable dissipating element 4 and a sliding surface of the first 2 or of the second 3 connecting element. Further, the damping device 1 according to the invention enables said friction force to be modulated simply by appropriately varying the degree of overlap/contact and therefore of interference between said contact surface and said sliding surface.

[0045] The contact surface of the deformable dissipating element 4 and the sliding surface of the first 2 or of the second 3 connecting element have respective geometric profiles whose relative rotation around the longitudinal geometric axis X determines a variable geometric interference between a minimum value and a maximum value. In particular, the structure of the geometric profiles of said elements enables the geometric interference to be varied between a minimum value, corresponding to a nil dissipating action, and a maximum value, corresponding to a maximum dissipating action. [0046] The aforesaid geometric profiles are to be considered according to a cross section, i.e. according to a plane orthogonal to the longitudinal geometric axis X.

[0047] In the first embodiment, shown in Figures 1-9 and in Figure 11, the damping force is exerted between the outer surface of the deformable dissipating element 4, identified as contact surface 7, and the inner surface of the first connecting element 2, identified as sliding surface 8. Specifically, as shown in Figures 5, 7, 9, said deformable dissipating element 4 and said first connecting element 2 have elliptical geometric profiles.

[0048] Figures 10A-10D show, schematically, the aforesaid elliptical geometric profiles and enable to understand the operating principle that is based on the modulable geometric interference therebetween in function of the relative rotation between the two dissipating elements 4 and connecting elements 2.

[0049] In particular, Figures 10A-10D show an outer elliptical profile 60 and an inner elliptical profile 61. The inner elliptical profile 61 is expected to be concentric to the outer elliptical profile 60, and having axes whose length is less than the corresponding axes of the external elliptical profile 60. In particular, the major axis of the inner elliptical profile 61 must be longer than the minor axis of the external elliptical profile 60, so that there can be a modulable geometric interference between a maximum value and a minimum value when the contact and sliding surfaces, associated with the aforesaid elliptical profiles 60, 61, vary their angular position.

[0050] Figure 10A shows the configuration in which the two concentric elliptical profiles 60, 61 disclosed above are angularly arranged so that the geometric interference is minimal, in particular nil. By rotating the inner elliptical profile 61 anticlockwise, as indicated by the arrow in Figure 10B, which corresponds to an anticlockwise rotation of the second connecting element 3 that is integral with the deformable dissipating element 4, a configuration is reached in which there is a geometric interference between the two elliptical profiles 60, 61, as shown in Figures 10B and IOC. By further rotating the inner elliptical profile 61 anticlockwise, the point is reached in which the inner elliptical profile 61 is rotated by 90° with respect to the initial position, thus the major axis of the inner elliptical profile 61 is superimposed on the minor axis of the external elliptical profile 60. Owing to the geometric conditions disclosed above, the configuration represented in Figure 10D corresponds to the configuration in which there is the maximum geometric interference between the two concentric elliptical profiles 60, 61. In this condition of maximum mechanical interference, the parts of the deformable element 4 in contact with the sliding surface 8 of the first connecting element 2 are subjected to a state of compression against the same surface, giving origin in this manner to frictional actions of maximum amount to which a maximum dissipative action corresponds.

[0051] As a result, in the configuration shown in Figure 10A, there is no geometric interference between the two elliptical profiles 60, 61 and as a result no damping friction force is exerted; in the configuration shown in Figure 10D there is maximum geometric interference between the two elliptical profiles 60, 61 and, as a result, maximum friction damping force is applied; Figures 10B, IOC instead show an intermediate configuration between the first two cases.

[0052] The friction dissipating force value is thus continuously variable with the variation of the relative rotation angle between said outer elliptical profile 60 and said inner elliptical profile 61.

[0053] In one alternative embodiment that is not shown, the damping device 1 according to the invention can be made with geometric profiles that are shaped in such a way that the variation of the relative rotation angle around the longitudinal geometric axis X corresponds to a step variation of the generated friction force and thus of the dissipating action exerted.

[0054] In a second embodiment shown in Figure 12, the second connecting element 3 can be devoid of said protrusion 13. In this case, the deformable dissipating device 4 has an annular shape and is positioned at one end of said second connecting element 3 devoid of a protrusion. In said second embodiment, fixing screw means 30 can be provided that are shaped to engage in a hole 31 obtained in said second connecting element 3 to clamp the deformable dissipating element 4 to an end of the second connecting element 3. In this second embodiment, similarly to what was disclosed above for the first embodiment, the deformable dissipating element 4 moves integrally with the second connecting element 3 to which it is fixed. The dissipating friction force would be, in this case, performed between the outer surface of the deformable dissipation device 4, identified as contact surface 7, and the inner surface of the first connecting element 2, identified as sliding surface 8.

[0055] In a third embodiment shown in Figure 13, the second connecting element 3 can be shaped with a transverse annular seat 40 suitable for receiving the deformable dissipation device 4 of annular shape. The deformable dissipation device 4 is positioned so that the inner surface 17 of the deformable device 4 of annular shape comes into contact with the outer surface of the transverse annular seat 40 obtained in the second connecting element 3. The deformable dissipation device 4 is shaped to protrude partially from the annular seat 40 of the second connecting element 3. In this case, the deformable dissipating device 4 remains clamped inside the annular seat 40 without the need to provide for fixing by means of additional fixing elements. Also in said third embodiment, the deformable dissipating element 4 moves integrally with the second connecting element 3 into which it is inserted. Further, also in said third embodiment, the dissipating friction force would be applied between the outer surface of the deformable dissipation device 4, identified as contact surface 7, and the inner surface of the first connecting element 2, identified as sliding surface 8.

[0056] In a fourth embodiment shown in Figure 14, the deformable dissipating device 4 can be alternatively fixed to the first connecting element 2. In particular, the first connecting element 2 can be shaped with a transverse annular seat 50 suitable for receiving the deformable connecting device 4 of annular shape. The deformable dissipating device 4 is positioned so that the outer surface of the deformable device 4 of annular shape comes into contact with the inner surface of the transverse annular seat 50 obtained in the first connecting element 2. The deformable dissipating device 4 is shaped to protrude partially from the annular seat 50 of the first connecting element 2. In this case, the deformable dissipating device 4 remains clamped inside the annular seat 50 without the need to provide for fixing by means of additional fixing elements. In said fourth embodiment, the deformable dissipating element 4 moves integrally with the first connecting element 2 into which it is inserted. In this case, the dissipating friction force would be applied between the inner surface of the deformable dissipating device 4, identified as contact surface 7, and the outer surface of the second connecting element 3, identified as sliding surface 9.

[0057] From what has been disclosed and shown in the attached drawings, it is thus clear that the damping device 1 according to the invention achieves successfully all the objects stated above. In particular, the damping device 1 has a significantly simplified configuration in structural and functional terms. As a result, the damping device 1, in addition to being light and mechanically reliable, is particularly cheap to make, ensuring at the same time significantly useful performance and efficacy. For these reasons, the damping device 1 is particularly advantageous for use in low-cost applications, for example in household appliances that require vibrations to be damped during operation. [0058] What has been said and shown in the appended drawings, it has been provided by way of illustration of the innovative features of the damping device according to several possible embodiments; other modifications can be made to the various embodiments of the apparatus, or parts thereof, without thereby falling outside the claims.

[0059] In practice, the materials, insofar as they are compatible with the specific use and with the respective single components for which they are intended, can be chosen appropriately in function of the requested requirements and in function of the available prior art.

[0060] It is possible to configure and size the damping device 1 and adopt materials according to needs, and variations on and/or additions to what has been disclosed above and illustrated in the attached drawings are possible.

Claims

1. Damping device (1) suitable for being fitted to an apparatus for damping the vibrations thereof, comprising: a first connecting element (2), suitable for being connected to a first part (10) of said apparatus, a second connecting element (3), suitable for being connected to a second part (11) of said apparatus, said first part (10) and said second part (11) being relatively movable during operation of said apparatus, a deformable dissipating element (4) placed between said first connecting element (2) and said second connecting element (3) and having a contact surface (7) configured for coupling slidingly with a sliding surface (8;9) of said first connecting element (2) or of said second connecting element (3) to counteract, through effect of a friction action, the relative motion between said first connecting element (2) and said second connecting element (3), characterized in that said contact surface (7) and said sliding surface (8;9) are mutually positionable in rotation and geometrically configured for coupling with a mechanical interference that is variable according to an angular position of one with respect to the other, so as to adjust the mutual contact pressure and thus the degree of dissipation through effect of the friction.

2. Damping device according to claim 1, wherein said first connecting element (2) is a tubular element having an inner cavity (5) that extends with a longitudinal axis (X), and wherein said second connecting element (3) is an oblong element configured for being received in said inner cavity (5) extending along said longitudinal axis (X).

3. Damping device according to claim 1 or 2, wherein said first (2) connecting element and said second (3) connecting element are relatively movable along said longitudinal axis (X) and are mutually rotatable around said longitudinal axis (X).

4. Damping device according to any one of claims 1 to 3, wherein said deformable element (4) is fixed to said second connecting element (3), said contact surface (7) is obtained on an outer surface of said deformable element (4), and wherein said sliding surface (8) is obtained on an inner surface of said first connecting element (2), so that said contact surface (7) is enclosed inside said sliding surface (8).

5. Damping device according to claim 4, wherein said deformable element (4) has an annular shape and is fitted on a protrusion (13) projecting from an end of said second connecting element (3), fixing means (15, 16) being provided for clamping said deformable element (4) to said second connecting element (3).

6. Damping device according to claim 4, wherein said deformable element (4) has an annular shape and screw means (30) is provided shaped to engage in a hole (31) obtained in said second connecting element (3) to fix said deformable element (4) to an end of said second connecting element (3).

7. Damping device according to any one of claims 1 to 3, wherein said deformable element (4) has an annular shape and is fixed to said first connecting element (2), said contact surface (7) is obtained on an inner surface of said deformable element (4), and wherein said sliding surface (9) is obtained on an outer surface of said second connecting element (3), so that said contact surface (7) extends externally around said sliding surface (9).

8. Damping device according to claim 7, wherein said deformable element (4) is housed in an annular seat (50) obtained on the inner surface of said first connecting element (2).

9. Damping device according to any one of the preceding claims, wherein said deformable element (4) is made of an elastically deformable material.

10. Damping device according to any one of the preceding claims, further comprising an adjusting member (20) for adjusting the relative angular position between said deformable element (4) and said first (2) connecting element or said second (3) connecting element.

11. Vibration damping device according to the preceding claim, wherein said adjusting member (20) is of manual type.

12. Vibration damping device according to claim 10, wherein said adjusting member (20) is of electromechanical type.

13. Damping device according to claim 2 or according to any one of claims 2 to 12 as appended to claim 2, wherein said contact surface (7) and said sliding surface (8; 9) have, according to a section that is transverse to said longitudinal axis (X), respective geometric profiles whose relative rotation around said longitudinal axis (X) determines a geometric interference that is variable between a minimum value, corresponding to a nil dissipating action, and a maximum value, corresponding to a maximum dissipating action.

14. Damping device according to the preceding claim, wherein said geometric profiles comprise an outer elliptical profile (60) and an inner elliptical profile (61), concentric to said outer elliptical profile (60), and having axes of length shorter than the respective axes of said outer elliptical profile (60), wherein the major axis of said inner elliptical profile (61) is longer than the minor axis of said outer elliptical profile (60), so that the value of the friction force, and thus of the dissipating action, is continuously variable with the variation of the angle of relative rotation between said outer elliptical profile (60) and said inner elliptical profile (61).

15. Damping device according to claim 13, wherein said geometric profiles are shaped in such a way that the variation of the angle of relative rotation around said axis (X) corresponds to a step variation of the friction force generated, and thus of the dissipating action exerted.