AXIAL DAMPING DEVICE WITH ELASTOMERS

Abstract

A device (5, 20) is described for isolating and damping uniaxial vibrations to be interposed between rigid elements (2, 3) in relative motion, comprising damping and insulating means (15) in elastomeric material, suitable for performing this function of insulation and damping through repeated deformations and consequent hysteresis of the elastomeric material; the device (5, 20) comprises: a first head (11); at least two sleeves (11a) integral with the first head (11); a second head (12); at least two bars (13) which are inserted at a first end in the sleeves (11a) and are connected at a second end with the second head (12); at least one stabilizing jacket (14); and an elastic element (15) which is interposed between the first head (11) and the second head (12), reacting to compression when, due to the application of the load, the damper device (5, 20) is shortened.

Claims

1. Device (5, 20) for isolating and damping uniaxial vibrations by being interposed between rigid elements (2, 3) in relative motion, of the type comprising damping and insulating means (15) in elastomeric material, suitable for performing an insulation and damping function through repeated deformations and consequent hysteresis of the elastomeric material, comprising: a first head (11); at least two sleeves (11a) integral with the first head (11); a second head (12); at least two bars (13) which are inserted at a first end in the sleeves (11a) and are connected at a second end with the second head (12); at least one stabilizing jacket (14); an elastic element (15) which is interposed between the first head (11) and second head (12), reacting to compression when, due to the application of the load, the damper device (5, 20) is shortened; characterized in that: the at least one stabilizing jacket (14), slides on the bars (13); the elastic element (15) is prismatic m shape.

2. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 1, characterized in that the device is a connecting rod (5, 20) connected to the rigid elements (2, 3) by means of spherical hinges (6, 7) applied to the ends of the connecting rod (5, 20).

3. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 2, characterized in that the connecting rods (5, 20) are connected with the spherical hinges (6, 7) by means of a pin (10) which screws on the heads (11, 12) and on the balls (6a, 7a) of the spherical hinges (6, 7).

4. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 1, characterized in that the connecting rods (5, 20) are mounted in the working position by applying a suitable preload, so that the stress on the elastomeric prismatic element (15) is always compression, in any working situation due to vibrations.

5. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 1, characterized in that the prismatic element (15) is made of neoprene.

6. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 2, characterized in that the connecting rods (5, 20) are mounted in the working position by applying a suitable preload, so that the stress on the elastomeric prismatic element (15) is always compression, in any working situation due to vibrations.

7. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 3, characterized in that the connecting rods (5, 20) are mounted in the working position by applying a suitable preload, so that the stress on the elastomeric prismatic element (15) is always compression, in any working situation due to vibrations.

8. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 2, characterized in that the prismatic element (15) is made of neoprene.

9. Device (5, 20) for isolating and damping uniaxial vibrations according to claim 3, characterized in that the prismatic element (15) is made of neoprene.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be better described by some preferred embodiments, provided by way of non-limiting example. The description will refer to a damper device that makes use of the connecting rod according to the invention, the device being illustrated in the attached drawings, in which:

[0030] a. FIGS. 1 and 2 are two views of a damper device which makes use of the connecting rods according to the present invention;

[0031] b. FIG. 3 shows the damper device under the effect of an applied vertical load;

[0032] c. FIG. 4 shows the basic structure of the device according to the invention;

[0033] d. FIGS. 5 and 6 show two possible embodiments of the connecting rod according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] Referring to FIGS. 1, 2 and 3, (1) designates a damper device which makes use of connecting rods (5) according to the present invention.

[0035] According to a preferred embodiment of the invention, the device (1) comprises: [0036] a. a lower plate (2) which, with the interposition of a sheet of elastomeric material (2a) rests on a support (2b); [0037] b. an upper plate (3) which, with the interposition of a sheet of elastomeric material (3a) acts as a support to a mass (3b); [0038] c. at least three trusses (4), each consisting of at least the three connecting rods (5), axially deformable, each of which is connected at its lower end (5a) with the lower plate (2) by means of first spherical hinges (6) and at its upper end (5b), with the upper plate (3), by means of second spherical hinges (7).

[0039] According to a preferred embodiment, illustrated in the attached figures, the trusses (4) are four in number for each damper, and each of the truss (4) comprises four connecting rods (5). In FIG. 2, the connecting rods (5) are indicated through their axis, so as not to excessively complicate the drawing.

[0040] Furthermore, there is preferably a plurality of spacing balls or linear guides (8), housed in corresponding seats (8a), the function of which will be described below.

[0041] According to a preferred embodiment, shown in the attached figures, the trusses are four in number for each damping device (1) and the connecting rods (5) are four in number for each truss (4).

[0042] The connecting rods (5) of the trusses (4) are arranged along the edges of a pyramid with the base resting on the lower plate (2).

[0043] When the mass to be supported is not resting on the damper device (1), the connecting rods (5) are inclined with respect to the plates (2, 3) by an angle between 0 and 60. When the load is applied, that is when the supported mass (3a) is placed on the upper plate (3), the connecting rods (5), due to the inclination, are subjected to compression and, being axially deformable, get shortened, allowing the upper plate (3), and then the supported mass (3a) to descend, until the spacing balls (8) rest against the upper plate (3) (FIG. 3).

[0044] The spacer balls or linear guides (8) are of such dimensions that, following the lowering of the upper plate (3), the connecting rods (5) are placed in a position substantially parallel to the plates (2) and (3). In this way, reciprocal sliding between the plates (2) and (3) gives rise to variations in length of the connecting rods (5), thus excluding shear stresses in the elastomeric elements.

[0045] FIG. 4 shows one of the trusses (4). According to a preferred embodiment, the lower spherical hinges (6) comprise a steel ball (6a) housed in a seat (6b) connected to the lower plate (2), while the upper spherical hinges (7) comprise a ball in steel (7a) housed in a seat (7b) connected to the upper plate (3).

[0046] The connecting rods (5) are, in turn, connected with the lower (6) and upper (7) spherical hinges by means of threaded pins (10) which are screwed to the balls (6a) and (7a) and to a first and a second head (11) and (12) of the connecting rods (5), as shown in the enlarged details of FIG. 4.

[0047] FIG. 5 shows a first embodiment of the connecting rod (5). The connecting rod (5) includes: [0048] a. the first head (11); [0049] b. at least two sleeves (11a) integral with the first head (11); [0050] c. the second head (12); [0051] d. at least two bars (13) which are inserted with a first end in the sleeves (11a) and are connected with a second end with the second head (12); [0052] e. at least one stabilizing jacket (14), sliding on the bars (13); [0053] f. an elastomeric element with a prismatic shape (15).

[0054] Two threaded holes are made on the heads (11) and (12), respectively (11b) and (12a), in which the threaded pins (10) are screwed, which have the function of connecting with the spherical hinges (6) and (7).

[0055] The prismatic elastomeric element (15) connects the two heads (11) and (12) together and reacts by shortening to the compressive stresses resulting from the shortening due to the application of the load.

[0056] When the compression load is applied, due to the high slenderness of the elastomeric component (13), it tends to skid laterally. This drawback is eliminated by the anti-skid pads (14), sliding on the bars (13), which surround the prismatic elastomeric element (15) and prevent lateral skidding thereof. The number of anti-skid pads (14) is calculated in such a way as to reduce the free deflection length of the elastomeric prism below the critical values.

[0057] FIG. 6 shows a connecting rod (20), conceptually similar to the connecting rod (5), as it is made up of the same components. The connecting rod (20) is less slender than the connecting rod (5), so as to give the device (1) greater horizontal stiffness. The number of anti-skid pads of the connecting rod (5) and connecting rod (20) depends on the horizontal load levels provided on the insulator.

[0058] According to a preferred embodiment (not shown), the connecting rods (5, 20) are already mounted in the position they would have after applying the load. Obviously it is advisable to carry out the assembly by applying an appropriate preload, so that the stress is always compressive, in any case of calculation and load of the insulator.