Adjustable passive vibration damper assembly

Abstract

Adjustable passive vibration damper assembly (100) comprising a damper housing (200) and a damper assembly (300) accommodated therein, the damper assembly (300) comprising a spring member (310), damping mass (320) and at least one damping liquid (330), wherein the length (L) of the spring member (310) interior the damper housing (200) is adjustable via a spring member fixation assembly (230).

Description

[0001] ADJUSTABLE PASSIVE VIBRATION DAMPER ASSEMBLY

[0002] The disclosed embodiments relate to an adjustable passive vibration damper assembly.

[0003] The disclosed embodiments relate especially to an adjustable passive vibration damper assembly utilizing the principle of a tuned mass damper (TMD) and that is applicable to resonant vibration problems in a wide frequency range, for both small and large constructions.

[0004] BACKGROUND

[0005] Vibration output is the result of the force input multiplied with the amplification of the mechanical system: D(f) = F f") * G( / )

[0006] Vibration can be reduced by either reducing the input force F( ) or the amplification G( / ) of the mechanical system. All parts of the equation are complex valued functions of the frequency. The highest vibration is experienced when the force frequency is high, at which frequency the system is responding strongly, wherein the frequency is at one of the natural frequencies of the mechanical system. The phenomenon that occurs if a force frequency is close to, or at the natural frequency, is called resonance and can occur for both sound and vibration.

[0007] Using vibration dampers is known to be an effective vibration-reducing measure for resonant / mechanical vibration, for many objects, such as piping and other constructions or structures. Installing a vibration damper can also be a more time- and cost-effective measure as most types can be installed during operation.

[0008] A tuned mass damper (TMD), also known as a vibration absorber or reaction mass damper, is a well proven technology for mitigating vibration. A TMD works by reducing the magnification at a specific natural frequency (G( )).

[0009] The damping principle of a TMD is described as a system consisting of a counter-acting mass, spring and damper, as shown in Fig. 1.

[0010] Adjustable TMDs are known in the prior art, e.g. from US6681908B2. In US’908B2 is disclosed a sealed TMD that is adjustable by utilizing an adjustment screw that is retracted or advanced, changing the number of active coils in a spring that engages a damping mass in the TMD. The screw adjustment changes the spring rate and the natural frequency of the spring-mass combination but does not compress the spring.

[0011] From WO 2022034140 Al is known a TMD for fastening to a component, the TMD containing at least two spring elements. At least one of spring elements is in the form of a material cushion, with at least one centrifugal mass arranged therebetween, wherein the sequence of spring element, centrifugal mass and spring element defines an axial direction. The spring elements are adjustably loaded toward each other by means of movement of a preloading apparatus in the axial direction, to modify the natural frequency of the TMD.

[0012] TMDs are also known from, e.g., https: / / www.momentum- technologies.no / products / momentum-tmd / (the applicant), https: / / www.sandvik.coromant.com / en-gb / tools / tooling-systems / turning-centres-and- lathes / sil ent-tools, https: / / www.betamachinery.com / assets / pdfs / products / DamperX_Vibration_Absorber_cut _sheet.pdf, and https: / / www.lisega.de / en / vibration-control-en / tuned-mass-dampers-tmd / .

[0013] There are many factors involved that one need to get right if the TMD shall be as effective as possible. Common for all TMDs is that one will have to find the appropriate selection and settings for mass and spring of the vibration damper assembly. The TMDs may further have damping features, not all TMDs has this feature, requiring that one further makes the appropriate selection and setting of the amount of damping of the vibration damper assembly. In addition to the mentioned factors, one also has to consider and adapt for the orientation and location of the vibration damper assembly. The disadvantage of this is that each vibration damper assembly must be tuned for each individual project and each delivered vibration damper assembly is therefore unique in its configuration.

[0014] Experience from damping of vibration in piping and other constructions or structures, show that there is a need for a vibration damper assembly that can be set into use quickly after a problem has been discovered. Situations where one does not have time or where it is not economically justifiable to spend a lot of time on tuning and / or a specially adapted and customized production of a vibration damper assembly.

[0015] Further there often is an uncertainty of the performance of vibration damper assemblies before installation, as even a good FEM (Finite Element Method) analysis and / or dynamic measurement will not perfectly find the relation between mass and spring, natural frequencies / damping of the system.

[0016] There is accordingly a need for an adjustable passive vibration damper assembly solving the above mentioned.

[0017] SUMMARY

[0018] The disclosed embodiments provide an adjustable passive vibration damper assembly for vibration suppression of a construction, structure or object.

[0019] Provided herein is an adjustable passive vibration damper assembly utilizing the principle of a tuned mass damper (TMD).

[0020] Provided herein is an adjustable passive vibration damper assembly that is applicable to resonant vibration problems in a wide frequency range. Also provided herein is an adjustable passive vibration damper assembly that is applicable at both small and large constructions, structures or objects.

[0021] Also provided herein is an adjustable passive vibration damper assembly that is adjustable to enable adaption and tuning in situ to achieve optimal reduction of vibration for the construction, structure or object in question.

[0022] Provided herein is an adjustable passive vibration damper assembly being compact.

[0023] Provided herein is an adjustable passive vibration damper assembly that will reduce the response / vibration of more than one natural frequency of the vibrating construction, structure or object in question.

[0024] Also provided herein is an adjustable passive vibration damper assembly enabling optimized damping.

[0025] Provided herein is an adjustable passive vibration damper assembly enabling the combination of modularity and adjustability.

[0026] Also provided herein is a passive vibration damper assembly that is maintenance free.

[0027] Provided herein is an adjustable passive vibration damper assembly that can be tailored to the construction, structure or object in question.

[0028] Also provided herein is an adjustable passive vibration damper assembly which is cheaper to manufacture, compared to prior art solutions.

[0029] THE INVENTION

[0030] An adjustable passive vibration damper assembly according to the present invention is defined by the technical features of claim 1. Preferable features of the adjustable passive vibration damper assembly are described in the dependent claims.

[0031] The present invention is related to an adjustable passive vibration damper assembly (APVDA) that enables the possibility to be used for damping out more than one vibration mode / natural frequency by the one and same APVDA.

[0032] The APVDA according to the present invention comprises a damper housing and a damper assembly accommodated therein. In accordance with the present invention, the damper assembly comprises a spring member, damping mass and at least one type of damping, for example viscous liquid or eddy current effect, further described below.

[0033] According to the APVDA of the present invention, the damper housing has a closed first end and open second end.

[0034] The spring member of the APVDA according to the present invention is arranged to the damping mass at a proximal (first) end and extends axially from the interior of the damper housing and to the exterior of the damper housing via a spring member fixation assembly arranged in the open second end of the damper housing.

[0035] In accordance with the APVDA of the present invention, the length of the spring member interior the damper housing is adjustable via the spring member fixation assembly. In this manner enabling a coarse adjustment of the length of the spring member.

[0036] According to the APVDA according to the present invention, the length of the spring member interior the damper housing is further adjustable via a spring member fine adjustment member arranged to a distal (second) end of the spring member via the spring member fixation assembly. Accordingly, the spring member fine adjustment member is arranged exterior the damper housing and enables fine / precise adjustment of the length of the spring member interior the damper housing.

[0037] According to the APVDA according to the present invention, the spring member fixation assembly is formed by a collet and a collet fastener arranged in the open end of the damper housing via a chuck. In this manner the fixation of the spring member to the damper housing is easily adjustable by tightening or loosening the collet.

[0038] In accordance with the APVDA according to the present invention, the spring member fine adjustment member is attached to the second end of the spring member and axially movable to the collet fastener, i.e. the end of the spring member being positioned outside the damper housing.

[0039] In accordance with a further embodiment of the APVDA according to the present invention, the length of the spring member interior the damper housing is further adjustable by the spring member being arranged to the damping mass at the proximal end via an attachment device being arranged axially movable in relation to the damping mass.

[0040] According to a further embodiment of the APVDA according to the present invention, the damping mass comprises a main mass member or the damping mass is modular and comprising a main mass member and at least one additional mass member arranged in the axial extension thereof. By having a modular damping mass, the properties thereof can be easily adjusted by adding or removing mass members.

[0041] In accordance with a further embodiment of the APVDA according to the present invention, the main mass member is provided with an axial recess configured for receiving and accommodating the proximal end of the spring member and the attachment device attaching the spring member thereto.

[0042] According to a further embodiment of the APVDA according to the present invention, the additional mass members are provided with respective axially through holes configured for receiving and accommodating the spring member extending therethrough.

[0043] In accordance with a further embodiment of the APVDA according to the present invention, at least one magnet is arranged to or integrated in the damping mass and wherein the damper housing is entirely or partly formed by a nonferrous material, providing eddy current damping effect.

[0044] According to a further embodiment of the APVDA according to the present, at least one magnet is arranged to or integrated in the lower art of the damper housing and wherein the damping mass is partly or entirely of a nonferrous material or covered or enclosed partly or entirely in a nonferrous material.

[0045] According to a further embodiment of the APVDA according to the present invention, the spring member is formed by a coil spring with solid or rigid end parts.

[0046] In accordance with a further embodiment of the APVDA according to the present invention, the APVDA further comprises a protective encapsulation configured to be arranged to the damper housing in the extension of the open second end thereof and enclosing the spring member fixation assembly and spring member fine adjustment member for protection thereof.

[0047] According to a further embodiment of the APVDA according to the present invention, the APVDA further comprises an attachment assembly for attachment of the adjustable passive vibration damper assembly to a construction, structure or object to be vibration damped.

[0048] In accordance with a further embodiment of the APVDA according to the present invention, the APVDA comprises one or more actuators enabling remote or automated controlling of the length of the spring member interior the damper housing, for fine adjustments of the length of the spring member.

[0049] According to a further embodiment of the APVDA according to the present invention, the APVDA is configured for enabling tuning for damping of more than one natural frequency of the vibrating construction, structure or object.

[0050] In accordance with one embodiment of the APVDA according to the present invention, the damping mass is configured for movement in parallel to the damper housing.

[0051] By the present invention is thus provided an APVDA that solves the mentioned problems of prior art systems.

[0052] The APVDA according to the present invention has many application areas and is easily adjustable and configurable in relation to the construction, structure or object to be damped.

[0053] By the APVDA according to the present invention one further has the possibility to address more than one vibration mode / natural frequency in the one and same APVDA.

[0054] Further preferable features and advantageous details of the present invention will appear from the following example description. EXAMPLE

[0055] The present invention will below be described in further detail with references to the attached drawings, where:

[0056] Fig. la is a principle drawing of the damping principle of a tuned mass damper,

[0057] Fig. Ib-c are principle drawings illustrating vibration modes of a construction, structure or object,

[0058] Fig. 2 is a principle drawing of one embodiment of an adjustable passive vibration damper assembly according to one embodiment of the present invention,

[0059] Fig. 3a is a principle drawing of how a coarse adjustment of spring member length of the adjustable passive vibration damper assembly according to one embodiment of the present invention is achieved,

[0060] Fig. 3b is principle drawing of how a fine adjustment of the spring member length of the adjustable passive vibration damper assembly according to one embodiment of the present invention is achieved,

[0061] Fig. 4a-b are principle drawings of further embodiments of an adjustable passive vibration damper assembly according to the present invention wherein enabling adjustable attachment of spring member to the damping mass,

[0062] Fig. 5 is a principle drawing of a further embodiment of the adjustable passive vibration damper assembly according to the present invention,

[0063] Fig. 6a-b are principle drawings of further embodiments of the adjustable passive vibration damper assembly according to the present invention comprising eddy current damping,

[0064] Fig. 7a-d are principle drawings of different embodiments of arrangement of the adjustable passive vibration damper assembly according to the present invention to a construction, structure or object for vibration damping thereof,

[0065] Fig. 8 is a principle drawing of a further embodiment of the adjustable passive vibration damper assembly according to the present invention comprising a protective encapsulation, and

[0066] Fig. 9 is a principle drawing of a further embodiment of the adjustable passive vibration damper assembly according to the present invention comprising spring member shaped as a coil spring.

[0067] Reference is now made to Fig. Ib-c showing principle drawings illustrating how a construction, structure or object 500 is affected by vibration. Rarely is it only one single natural frequency that affects a vibration problem of a construction, structure or object 500. A construction, structure or object 500 has several natural frequencies (eigen frequencies) and for each natural frequency there is a unique vibration mode, as shown in Fig. lb, were a first natural frequency is affecting the construction, structure or object 500 in the horizontal plane (translational vibration mode) and, as shown in Fig. 1c, where were a second natural frequency is affecting the construction, structure or object 500 in the vertical plane. Such natural frequency may also work in rotational and / or rocking vibration modes, not shown. This needs to be addressed when tuning a vibration damper assembly.

[0068] The most common solution for addressing such vibration is to use a tuned mass damper (TMD), see Fig. la, and there exist many different types of such TMDs. The prior art solutions suffer from that they are not configured to address and damp out frequencies within both lower and higher frequency ranges within the same design / construction. As discussed above, many of the present TMDs further lack damping as a separate adjustable component in the TMD and thus also possibility to adjust / tune the amount of damping in the TMD. Accordingly, the existing TMDs are directed to solving only one limited frequency range and further, only to the specific frequency tuned for.

[0069] Reference is now made to Fig. 2 showing a principle drawing of a first embodiment of an adjustable passive vibration damper assembly (APVDA) 100 according to the present invention. In accordance with the present invention, the APVDA 100 comprises a damper housing 200 and a damper assembly 300 accommodated therein. In the shown embodiment, the damper housing 200 is an elongated damper housing 200 with an extension in axial direction. In accordance with the present invention, the damper assembly 300 of the APVDA 100 according to the present invention comprises a spring member 310, damping mass 320 and one damping liquid 330. The damping liquid 330 is, e.g., but not limited to, a viscous liquid, such as Silicone oil, Polybutene and similar viscous liquids that will be within the knowledge of the skilled person within the art. The at least one spring members 310 is, e.g., spring steel, piano wire and similar spring members that will be within the knowledge of a skilled person within the art. The damping mass 320 is, e.g., but not limited to, of tungsten alloy, lead or similar materials or compositions that will be within the knowledge of a skilled person within the art.

[0070] The damper housing 200 has a closed first (rear) end 210 and open second (front) end 211.

[0071] In accordance with one embodiment of the present invention, the spring member 310 is arranged to the damping mass 320 at a proximal end via an attachment device 325, further described below, and extends axially from the interior of the damper housing 200 and to the exterior of the damper housing 200 via a spring member fixation assembly 230 arranged in the open second end 211 of the damper housing 200.

[0072] The mentioned at least one damping / viscous liquid 330 is enclosing the damping mass 320 and parts of the spring member 310 interior in the damper housing 200. The open second end 211 of the elongated damper housing 200 is configured to receive and accommodate a chuck 220, the function thereof described further below.

[0073] The (elongated) damper housing 200 and chuck 220 are provided with corresponding connection means (not shown) for mutual connection. In accordance with one embodiment of the APVDA 100 according to the present invention, the front part of the damper housing 200 is provided with internal threads (not shown) and the chuck 220 is provided with corresponding external threads (not shown) in a base part 221 thereof for mutual engagement and attachment of the chuck 220 to the second open end 211 of the damper housing 200.

[0074] The damping mass 320 is configured to be accommodated within damper housing 200 with a spacing therebetween, enabling space for damping (viscous) liquid 330 to enclose all sides of the damping mass 320. In accordance with one embodiment of the APVDA 100 according to the present invention, the damping mass 320 is formed by a main mass member 321. In alternative embodiments, the damping mass 320 is modular and comprising one or more additional mass members 322-323 arranged in series to the main mass member 321, in axial direction of the damping mass 320 and thus APVDA 100. The mentioned main mass member 321 forms the rear part of the modular damping mass 320, while the additional mass members 322-323, if present, are arranged to the main mass member 321 in the axial extension thereof. The respective mass members 321-323 are provided with corresponding attachment means (not shown) for mutual connection.

[0075] The main mass member 321 is at the side facing the spring member 310 provided with an axial recess 324 configured to receive and accommodate the proximal end (rear part) of the spring member 310, and further provided with the attachment device 325 for attachment of the proximal end (rear end) of the spring member 310 to the main mass member 321.

[0076] The additional mass members 322-323 are provided with respective axially through holes 326, 327 configured to receive and accommodate the spring member 310 extending axially therethrough, from the main mass member 321 and to the exterior of the damper housing 200.

[0077] The spring member 310 is with the distal (front) end extending out of the open second end 211 of the damper housing 200 via the spring member fixation assembly 230. In accordance with one embodiment of the present invention, the spring member fixation assembly 230 is formed by a collet 231 and a collet fastener 240 that is arranged to the damper housing 200 via the chuck 220, enabling fixation of the spring member 310 in relation to the damper housing 200.

[0078] In accordance with one embodiment of the APVDA 100 according to the present invention, the chuck 220 comprises an upwards from the base part 221 protruding flange 222 with an axially extending through hole 223. The through hole 223 of the flange 222 has at the base part 221 an initial interior circumference configured to receive and accommodate the spring member 310 with a spacing and extends in a first part with an increasing interior circumference from the base part 221 to a second part with a final interior circumference, i.e. the remaining part of the axially through hole 223 of the flange 222.

[0079] The second part of the through hole 223 of the flange 222 is configured with an interior circumference adapted to receive and accommodate the spring member 310 and spring member fixation assembly 230, i.e. collet 231 and collet fastener 240.

[0080] The mentioned first part of the through hole 223 is adapted for receiving a first inclined end of the collet 231. The collet fastener 240 is according to one embodiment of the present invention formed by an elongated tubular body 241 provided with a through hole 242 configured for receiving and accommodating the spring member 310 with a spacing therebetween. The collet fastener 240 is at a first end thereof, i.e. the end facing the chuck 220, configured to receive and accommodate the second (opposite) inclined end of the collet 231. The collet fastener 240 and flange 222 are further provided with mutual attachment means (not shown) for detachable attachment to each other. According to one embodiment of the APVDA 100 according to the present invention, the outer circumference of the first end of the collet fastener 240 is provided with threads (not shown) configured for mutual engagement with corresponding interior threads (not shown) of the flange 222 of the chuck 220 for loosening and tightening of the collet 231 to the chuck 220, and enclosing and retaining the spring member 310 when tightened and releasing the retainment of the spring member 310 when loosened. Accordingly, in the present invention, axial movement of the collet fastener 240 affects the collet 231 whether to tighten or loosen the spring member 310 and enable axial movement and adjustment of the length L thereof, further described below.

[0081] The damper housing 200, chuck 220 and spring member fixation assembly 230 thus forms a sealed damper volume for accommodating the damper (viscous) liquid 330. To enable a sealed damper volume, the APVDA 100 comprises at last one sealing member 213 associated with the chuck 220, sealing against the spring member 310 in connection with the extension thereof through the chuck 220 and out of the damper housing 200. The at least one sealing member 213 is, e.g., arranged interior in the chuck 220, facing the interior of the damper housing 200. The sealing member 213 is omitted in the remaining figures for simplification.

[0082] In accordance with a further embodiment of the present invention, the spring member 310 is at the distal free end, i.e. the end positioned outside the damper housing 200, provided with a spring member fine adjustment member 340. I.e. the spring member fine adjustment member 340 is arranged to the spring member 310 at the distal end, i.e. the opposite end from the end attached to the damping mass 320, enabling axial adjustment of the length L of the spring member 310 inside the damper housing 200. In the shown embodiment the spring member fine adjustment member 340 has an inner elongated body 341 adapted to receive and accommodate the distal free end of the spring member 310 and rotationally fixed thereto. In accordance with one embodiment, the spring member fine adjustment member 340 is adjustably arranged to the collet fastener 240 by the spring member fine adjustment member 340 comprising a downwards protruding flange 342 exterior of the elongated body 341 enclosing the collet fastener 240 and arranged in engagement therewith.

[0083] In accordance with one embodiment of the present invention, the collet fastener 240 comprises exterior threads (not shown) at the second end and the downwards protruding flange 342 comprises corresponding interior threads (not shown) for mutual engagement and axial adjustment of the spring member fine adjustment member 340 in relation to the collet fastener 240.

[0084] In this manner there is provided a fine adjustment, micrometer precision, of the length L of the spring member 310, further described below.

[0085] The elongated body 341 will typically be closed at the free end thereof.

[0086] Reference is now made to Fig. 3a. In accordance with the shown embodiment in Fig. 2 of the APVDA 100 according to the present invention, the length L of the spring member 310 inside the damper housing 200 is adjustable by loosening the collet 231 by axial movement of the collet fastener 240 and performing a coarse adjustment of the spring member 310 length L before tightening the collet 231 by axial movement of the collet fastener 240 again and retaining / fixation of the spring member 310. In addition, the spring member 310 may be adjustable by being of different lengths, being assembled of sections and / or be configured to be cut to adjust the physical length of the spring member 310.

[0087] Reference is now made to Fig. 3b. In accordance with the shown embodiment in Fig. 2 of the APVDA 100 according to the present invention, the length L of the spring member 310 inside the damper housing 200 is also adjustable by turning the spring member fine adjustment member 340 in relation to the collet fastener 240 to provide a fine adjustment of the length L of the spring member 310 inside the damper housing 200. By applying an axial displacement L2 of the spring member fine adjustment member 340 in relation to the collet fastener 240 this results in that the spring member 310 is axially displaced in the damper housing 200 with length L2. To perform the mentioned fine adjustment of the length L of the spring member 310 inside the damper housing 200, the spring member fixation assembly 230 must be loosened and tightened as described above. Accordingly, the spring member fine adjustment member 340 may be used alone or in combination with the coarse adjustment described in Fig. 3a. In Fig. 3b the spring member 310 is moved axially to a length L inside the damper housing 200 that is a length L2 shorter than the length L before adjustment. Reference is now made to Fig. 4a-b showing a further embodiment of the APVDA 100 according to the present invention, wherein the attachment device 325 of the spring member 310 in the damping mass 320, i.e. main mass member 321, is adjustable in axial direction of the main mass member 310. Accordingly, also this embodiment enables adjustment of the length L of the spring member 310 interior in the damper housing 200 by an adjustment L3 provided by the axial displacement in the adjustment of the attachment device 325. In addition to the adjustment of the spring member 310 length L in the damper housing 200, this also results in adjustment of center of damping mass 320 in the APVDA 100, i.e. adjusting the point of the affection of the damping mass 320. In Fig. 4a is shown an embodiment where the physical length of the spring member 310 is the same, but wherein the spring member 310 is moved axially in the APVDA 100 as described above, at the same time as the attachment device 325 moves in axial direction of the main mass member 321. In Fig. 4b is shown another embodiment where the physical length of the spring member 310 is adjusted by removing sections or cutting of pieces thereof or wherein the spring member 310 is exchanged with a different spring member 310 of shorter length. Accordingly, if there is not enough space available axially for adjustments as describe above under Fig. 3a-b, the spring member 310 will be shortened or exchanged. The adjustment will typically be performed before the chuck 220 is attached, but may also be performed by loosening the spring member fixation assembly 230 as described above.

[0088] Reference is now also made to Fig. 5 showing a further embodiment of the APVDA 100 according to the present invention. In accordance with the present invention, by that the APVDA 100 according to one embodiment comprises a modular damping mass 320, enabled is adjustment / modification of the properties of the APVDA 100 for spring member 310 and damping mass 320 by different combinations of a range of prefabricated damping mass members 321-323 so that the damper frequency and (counter-acting) damping mass 320 is tailored to suit the construction, structure or object 500 for which the APVDA 100 is desired to damp vibration for. In Fig. 5 and Fig. 9 are shown embodiments with only the main mass member 321, while Fig. 2, 3a-b, 4a-b, 6a- b, and 7a-d show embodiments with additional mass members 321-322. The mentioned additional mass members 322-323 may be of different size and properties, such as shape, density, etc. to modify the properties of the damping mass 320. In addition to add or remove weight for the damping mass 320, the size and properties (shape) of the damping mass 320 also affects the available volume interior of the damper housing 200 for the damping (viscous) liquid 330. Accordingly, the damping mass 320 may in an alternative embodiment also comprise additional mass member 322-323 that mainly are used for modifying the available volume for the damping (viscous) liquid 330 in the damper housing 200.

[0089] Furthermore, the properties and volume of the damping liquid 330 can according to the present invention be adapted to optimize the damping desired from the APVDA 100 by mixing pre-specified and available variants of liquids, such as variants of Silicone oil, Polybutene or similar (viscous) liquids. In this manner, the damping liquid 330 in the APVDA 100 according to the present invention can be configured to achieve an optimized damping (viscous) liquid 330 (damping element) that will provide a more broad-banded effect, as well as will make the APVDA 100 more robust to dynamic changes of the construction, structure or object 500 to be damped by the APVDA 100. E.g. by using a damping liquid 330 or liquid composition that has a high viscosity, a different frequency range is achieved for the APVDA 100 than a damping liquid 330 or liquid composition with a lower viscosity.

[0090] Reference is now made to Fig. 6a-b showing further embodiments of the APVDA 100 according to the present invention. In accordance with the shown embodiments, the APVDA 100 is provided with eddy-current damping features. According to one embodiment of the present invention, as shown in Fig. 6a, this is achieved by arranging or integrating at least one magnet 350 to / in the damping mass 320 and wherein the damper housing 200 partly or entirely is formed by aluminum or another magnetic material at the closed first end 210 (lower end). Accordingly, in the APVDA 100 according to this embodiment, the at least one magnet 350 will be a part of the damping mass 320 and the at least one magnet 350 will act with the magnetic (parts) of the damper housing 200 to provide an eddy current damping effect. In alternative embodiment, as shown in Fig. 6b, the damper housing 200 is at the closed first end 210 (lower end) provided or integrated with at least one magnet 350 and wherein the damping mass 320 are nonferrous or covered / enclosed partly or entirely in a nonferrous material. Accordingly, in the embodiment of Fig. 6b the at least one magnet 350 and the magnetic damper mass 320 will provide an eddy current damping effect similar to the embodiment of Fig. 6b.

[0091] The number and strength of the magnets 350, as well as the amount or type of nonferrous material in the damper housing 200 or covering / enclosure of the damping mass 320, will be configurable to modify the properties of the APVDA 100 to desired eddy current damping effect properties.

[0092] To achieve the mentioned eddy current effect, the magnetic field provided by the at least one magnet 350 is according to the present invention configured in the transversal direction of the movement of the damper assembly 300, i.e. transversal direction to the axial direction of the APVDA 100.

[0093] Reference is now made to Fig. 7a-d showing different embodiments of the APVDA 100 according to the present invention arranged to a construction, structure or object 500 to be vibration damped. The APVDA 100 according to the present invention is provided with an attachment assembly 400 for arrangement of the APVDA 100 to the mentioned construction, structure or object 500 to be vibration damped. The attachment assembly 400 is, e.g., formed by a flange bolt mounting or a mono- or dual-clamp or other suitable attachment assemblies. In Fig. 7a is shown an embodiment where the APVDA 100 is arranged to the construction, structure or object 500 by means of an attachment assembly 400 in the form of a dual clamp and in Fig. 7b the APVDA 100 is arranged to the construction, structure or object 500 by means of an attachment assembly 400 in the form of a mono-clamp, and wherein the orientation of the axial direction of the APVDA 100 is in axial direction of the construction, structure or object 500. In Fig. 7c is shown another embodiment of the attachment assembly 400, where the attachment assembly 400 comprises an attachment sleeve 410 configured to be attached to a lower end of the APVDA 100 via suitable attachment means 411, such as fixation bolts 411 and corresponding threaded holes in a facing structure of the damper housing 200. The mentioned attachment sleeve 410 is thus protruding from lower end of the damper housing 200 and configured for engagement with an attachment bolt 510 protruding from the construction, structure or object 500. The attachment sleeve 410 is, e.g., provided with interior threads (not shown) and the attachment bolt 510 is provided with corresponding exterior threads (not shown), enabling detachable attachment of the APVDA 100 to the construction, structure or object 500. In Fig. 7d is shown a similar solution as in Fig. 7c, but in this embodiment, the attachment sleeve 410 is arranged to the elongated protective encapsulation 360, further described below, configured to be arranged to the open second end 211 of the damper housing 200 via one end thereof, wherein the mentioned attachment sleeve 410 is arranged to a second (opposite) closed end thereof and protruding in the extension thereof. As for the embodiment in Fig. 7c the attachment sleeve 410 is configured for engagement with an attachment bolt 510 of the construction, structure or object 500. In the embodiments of Fig. 7c-d the orientation of the axial direction of the APVDA 100 is in transversal direction of the axial direction of the construction, structure or object 500.

[0094] Accordingly, the APVDA 100 according to the present invention can be arranged to the construction, structure or object 500 by different attachment methods and in different orientations. How the construction, structure or object 500 vibrates and which vibration mode to be damped will have to be considered when deciding the orientation of the APVDA 100 in relation to the construction, structure or object 500, and thus the type and properties of the attachment assembly 400. Further methods for attachment of the APVDA 100 to a construction, structure or object 500 will be within the knowledge of a skilled person in the art.

[0095] Reference is now made to Fig. 8 showing a further embodiment of the APVDA 100 according to the present invention, wherein comprising an elongated protective encapsulation 360 configured to be arranged to the damper housing 200 at the open second end 211 in the extension thereof and enclosing the chuck 220, spring member fixation assembly 230 and spring member fine adjustment member 340 for protection thereof. The damper housing 200 and elongated protective encapsulation 360 are provided with corresponding attachment means (not shown) for detachable attachment thereof. E.g. the damper housing 200 and elongated protective encapsulation 360 are provided with mating flanges with threads. In this manner it is provided an APVDA 100 that is entirely encapsulated, making it suitable for use in environments setting demands regarding hygiene, pressure, material compatibility, etc. The adjustability is remained by introducing a remote / automatic control of the fine adjustment of the length of the spring member 310, further described below.

[0096] Due to the spring member 310 fine adjustment, the damper frequency of APVDA 100 according to the present invention can be adjusted with a very high accuracy and to its perfection. The spring member 310 fine adjustment is advantageously done when the APVDA 100 is mounted to the construction, structure or object 500 with vibration of concern and that the APVDA 100 is attached to damp which enables a fine-tuned / exact and optimized solution. After the adjustment (coarse and / or fine) is performed, the spring member fixation assembly 230 tightened, and the elongated protective encapsulation 360 is attached.

[0097] An advantage with the modularity and adjustability of spring member 310 length L in the APVDA 100 according to the present invention, is that the spring member 310 length L can also be adapted if the construction, structure or object 500 to be damped changes its properties over time, in other words has a change of its dynamics.

[0098] In a further embodiment of the APVDA 100 according to the present invention, the APVDA 100 comprises at least one accelerometer 370, see Fig. 8, with a small display or wired or wireless communication means for communication with a handheld device, such as a tablet, phone or similar, that is used in assisting the tuning of the APVDA 100. The mentioned accelerometer 370 may be arranged to the damper housing 200, encapsulation 360 or other parts of the APVDA 100, or even the construction, structure or object 500. In this manner, one will enable installation and tuning to be made by clients / personnel with less experience / training in vibration and dynamics.

[0099] In accordance with a further embodiment of the APVDA 100 according to the present invention, the APVDA 100 further comprises at least one electric actuator 380-381 associated with the collet fastener 240 and spring member fine adjustment member 340, respectively, wherein the electric actuators 380-381 are configured for remote controlling via a wired or wireless communication interface. The mentioned electric actuators 3 SO- 381 may also use the wired or wireless interface of the accelerometer 370 or vice versa. The at least one electric actuator 380 associated with the collet fastener 240 is configured to enable axial movement of the collet fastener 240 in relation to the chuck 220 and thus enable loosening and tightening of the collet 231 engagement with the spring member 310 and thus enable axial adjustment of the spring member 310. The at least one electric actuator 381 associated with the spring member fine adjustment member 340 is configured to enable axial movement of the spring member fine adjustment members 240 in relation to the collet fastener 240 and thus fine adjustment / fine-tuning of the spring member 310. By this is enabled an automated or remote control of the spring member fine adjustment member 310.

[0100] Accordingly, by that the spring member 310 is arranged in the APVDA 100 by a fixation assembly 230 according to the present invention, this enables a wide range of possibilities to adjust the spring member 310 length L as discussed above, and in addition one can adjust the center / affection point of the damping mass 320, as well as the properties of the damping mass 320 and / or the damping liquid 330.

[0101] The APVDA 100 according to the present invention thus provides the ability to individually control at least two natural frequencies to the APVDA 100 and therefore enable damping of at least two different modes of vibration / natural frequencies of the vibrating construction, structure or object 500 in the same APVDA 100.

[0102] As discussed above, the at least two frequencies in the APVDA 100 have contribution from translational, vertical and / or rotational (rocking) vibration modes. Due to the adjustment features of the APVDA 100 according to the present invention both natural frequency and vibration mode can be controlled. By this is, for example, enabled that one can achieve that the first natural frequency of the APVDA 100 only is acting in translational mode and the second natural frequency is only acting in rotational mode, something that is not possible with the prior art solutions.

[0103] Due to that at least two vibration modes in the APVDA 100 according to the present invention can be controlled individually, this also enable synchronization of vibration modes. By synchronizing / tuning the at least two vibration modes one can achieve a combination of vibration modes so that the damping mass 320 will have a movement parallel to the damper housing 200. The damping effect may be significantly increased due to this feature, hence the same damping mass 320 is utilized in a more efficient way with regard to the plane the APVDA 100 is acting towards, something that is not possible with the prior art solutions.

[0104] The APVDA 100 according to the present invention further enables damping of torsional vibration mode. By the APVDA 100 according to the present invention is enabled the possibility to also damp torsional vibration, as well as enable tuning thereof by selection of torsional stiffness (length and thickness) of the spring member 310 and moment of inertia (length and diameters) of the damping mass 320 combined, something that is not possible with the prior art solutions.

[0105] A further advantage of APVDA 100 according to the present invention over the prior art solutions is that the APVDA 100 according to the present invention has multiple degrees of freedom. The APVDA 100 according to the present invention works in multiple degrees of freedom and is not limited to one / one plane as most of the prior art solutions.

[0106] Reference is now made to Fig. 9 showing a further embodiment of the APVDA 100 according to the present invention. In the shown embodiment the spring member 310 is realized by a coil spring 311 with solid or rigid end parts 312 and 313 for arrangement to the damping mass 320, fixation assembly 230 and spring member fine adjustment member 340, respectively. By realizing the main part 311 of the spring member 310 as a coil spring, the APVDA 100 will also work in axial and torsional directions, enabling all six degrees of freedom (2 x lateral, 2 x rocking, axial, torsion) for the damping mass 320.

[0107] A further advantage of the APVDA 100 according to the present invention is that the APVDA 100 is a passive vibration damper that will not require any power, hydraulics, instrumentation etc., besides from the above described embodiment for adjustment purposes (actuator 380-381, accelerometer 370, etc.).

[0108] A further advantage with the APVDA 100 according to the present invention is that it is temperature stable. None of the components of the APVDA 100 will be considerably affected by the environmental temperature affecting the APVDA 100. With the use of at least one viscous liquid 330 as damping, the APVDA 100 will also maintain the same damping performance at temperatures far below 0°C, of course depending of the viscous liquid(s) 330 chosen. E.g., solutions solely based on eddy current damping are known to have reduced damping effect at low temperatures.

[0109] By the present invention is further provided an APVDA 100 that is robust, due to the components are well protected from the environment in the damper housing 200 and will withstand transient loads and fatigue.

[0110] By the present invention is provided an APVDA 100 that will save the costs of manufacturing, compared to the prior art solutions. The APVDA 100 according to the present invention is applicable to a broad range of vibration problems by that the damping mass 320 is modular and the spring member 310 is easily adjustable / tunable, as well as the spring member 310, damping mass 320 and damping liquid 330 and the properties of the ones are individually adjustable and the interactions therebetween are easy to tune and adjust. This will contribute to low costs of manufacturing.

[0111] The APVDA 100 is further compact and suitable for small constructions, structures or objects 500. The building size of the APVDA 100 can be optimized to provide vibration reduction by a very small device. This will be very useful in small spaces and / or where access is limited. This is enabled by using high density materials in the counter-acting mass (damping mass 320), and by having a light weight and compact damper housing 200.

[0112] The principles and components of the APVDA 100 are further scalable, enabling the use of the principles thereof for both small and large constructions, structures or objects 500 that requires addressing vibration problems.

[0113] When the APVDA 100 is adjusted and set, the APVDA 100 is maintenance free, but may be adjusted if the situation changes requiring the APVDA 100 to be adjusted.

[0114] The APVDA 100 according to the present invention has a wide area of use and is applicable for solving more or less all types of resonant vibration problems.

[0115] Non-limiting application examples that the APVDA 100 according to the present invention is suitable for are: piping, motor parts, pump parts, compressor parts, coils in heating / cooling exchange systems, poles, parts in medical machinery, aeroplane or aircraft bodies, aeroplane or aircraft interior parts, vehicle bodies, vehicle interior parts, bridges, instruments, transmitters, tubing etc., basketball hoop assembly, in shafts of rotating machinery, etc. These examples show the unique possibilities of the APVDA 100 according to the present invention.

[0116] The embodiments described above may be combined to form modified embodiments within the scope of the attached claims.

Claims

CLAIMS1. Adjustable passive vibration damper assembly (100) comprising a damper housing (200) and a damper assembly (300) accommodated therein, the damper assembly (300) comprising a spring member (310), damping mass (320) and at least one damping liquid (330), wherein the damper housing (200) has a closed first end (210) and open second end (2H), wherein the spring member (310) is arranged to the damping mass (320) at a proximal end and extends axially from the interior of the damper housing (200) and to the exterior of the damper housing (200) via a spring member fixation assembly (230) arranged in the open second end (211) of the damper housing (200), wherein the length (L) of the spring member (310) interior the damper housing (200) is adjustable via the spring member fixation assembly (230), wherein the length (L) of the spring member (310) interior the damper housing (200) is further adjustable via a spring member fine adjustment member (340) arranged to a distal end of the spring member (310) via the spring member fixation assembly (230), wherein the spring member fixation assembly (230) is formed by a collet (231) and a collet fastener (240) arranged in the open end (211) of the damper housing (200) via a chuck (220), and wherein the spring member fine adjustment member (340) is attached to the distal end of the spring member (310) and axially movable to the collet fastener (240).

2. Adjustable passive vibration damper assembly (100) according to claim 1, wherein the length (L) of the spring member (310) interior the damper housing (200) is further adjustable by the spring member (310) being arranged to the damping mass (320) at the proximal end via an attachment device (325) being arranged axially movable in relation to the damping mass (320).

3. Adjustable passive vibration damper assembly (100) according to claim 1, wherein the damping mass (320) comprising a main mass member (321) or the damping mass (320) is modular and comprising a main mass member (321) and at least one additional mass member (322-323) arranged in the axial extension thereof.

4. Adjustable passive vibration damper assembly (100) according to claim 2-3, wherein the main mass member (321) is provided with an axial recess (324) configured for receiving and accommodating the proximal end of the spring member (310) and attachment device (325) attaching the spring member (310) thereto.

5. Adjustable passive vibration damper assembly (100) according to claim 3, wherein the at least one additional mass members (322-323) are provided with respective axiallythrough holes (326, 327) configured for receiving and accommodating the spring member (310) extending therethrough.

6. Adjustable passive vibration damper assembly (100) according to claim 1, wherein at least one magnet (350) is arranged to or integrated in the damping mass (320) and wherein the damper housing (200) is entirely or partly formed by a nonferrous material, or at least one magnet (350) is arranged to or integrated in the lower part of the damper housing (200) and wherein the damping mass (320) is covered or enclosed partly or entirely in a nonferrous material.

7. Adjustable passive vibration damper assembly (100) according to claim 1, wherein the spring member (310) is formed by a coil spring (311) with solid or rigid end parts (312, 313).

8. Adjustable passive vibration damper assembly (100) according to any preceding claim, wherein further comprising a protective encapsulation (360) configured to be arranged to the damper housing (200) in the extension of the open second end (211) thereof and enclosing the spring member fixation assembly (230) and / or spring member fine adjustment member (340) for protection thereof.

9. Adjustable passive vibration damper assembly (100) according to any preceding claims, wherein further comprising an attachment assembly (400) for attachment of the adjustable passive vibration damper assembly (100) to a construction, structure or object (500) to be vibration damped.

10. Adjustable passive vibration damper assembly (100) according to any preceding claims, wherein comprising one or more actuators (380-381) enabling remote or automated controlling of the length (L) of the spring member (310).

11. Adjustable passive vibration damper assembly (100) according to any preceding claims, wherein the adjustable passive vibration damper assembly (100) is configured for enabling tuning for damping of more than one natural frequency of the vibrating construction, structure or object (500).

12. Adjustable passive vibration damper assembly (100) according to any preceding claims, wherein the damping mass (320) is configured for movement in parallel to the damper housing (200).

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