Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
A VIBRATION ISOLATION SYSTEM
Document Type and Number:
WIPO Patent Application WO/2021/167568
Kind Code:
A1
Abstract:
The invention relates to at least one vibration isolation system (10) particularly for use in vibration isolation, comprising mainly at least one first region (20) and at least one second region (30) that are positioned mutually, at least one first hinge member (21) engaged with said first region (20), at least one second hinge member (31) engaged with said second region (30) and at least one lever (50) connected with said first hinge member (21) and said second hinge member (31) to be at least partially movable in the direction of at least one first axis (I). Accordingly, the novelty herein is that at least one lever guiding element (60) is used to minimize vibration transmission between the first region (20) and the second region (30) and said lever guiding element (60) is configured to bring an instantaneous center of rotation (II) depending on the input vibration frequency of the first region (20) to be aligned with the second hinge element (31) attached to the second region (30) which is required to be protected from vibration. In essence, the antiresonance frequency of the vibration isolation system (10) tracks the input vibration frequency and the vibration isolation system (10) always moves to the antiresonance condition even if the input frequency changes. The tuning process only depends on the vibrations in the source (first region (20)) and no external energy such as electrical energy is required. Thus, the system is self-powered. The lever guiding element achieves the self-tuning action by only mechanical means and hence it does not require any electronic sensors, actuators or control circuits.

Inventors:
YILMAZ CETIN (TR)
OZYAR AHMET ONUR (SE)
Application Number:
PCT/TR2021/050131
Publication Date:
August 26, 2021
Filing Date:
February 15, 2021
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
BOGAZICI UNIV (TR)
International Classes:
F16F15/06; E04H9/02; F16F15/00; F16F15/02; F16F15/067
Domestic Patent References:
WO1988003619A11988-05-19
Foreign References:
JP2001140981A2001-05-22
JP2013257027A2013-12-26
JP2007211503A2007-08-23
Attorney, Agent or Firm:
KAYA, Erdem (TR)
Download PDF:
Claims:
CLAIMS

1. At least one vibration isolation system (10) particularly for use in vibration isolation, comprising:

At least one first region (20) and at least one second region (30) that are located mutually,

At least one hinge element (21) engaged with said first region (20),

At least one second hinge element (31) engaged with said second region (30),

At least one lever (50) connected with said first hinge member (21) and said second hinge member (31) to be at least partially movable in the direction of at least one first axis (I), characterized in that, at least one lever guiding element (60) is positioned to minimize vibration transmission between the first region (20) and the second region (30), and said lever guiding element (60) is configured to align an instantaneous center of rotation (II) with the second hinge element (31).

2. A vibration isolation system (10) according to claim 1 , characterized in that, the lever guiding element (60) includes at least one wedge (61) to contact the lever (50).

3. A vibration isolation system (10) according to claim 2, characterized in that, said wedge (61) is mutually positioned to be in alignment with the second hinge element (31) connected to the second region (30) which is required to be isolated from vibration.

4. A vibration isolation system (10) according to claim 2, characterized in that, said wedge (61) comprises at least one first wedge (61a) and at least one second wedge (61b).

5. A vibration isolation system (10) according to claim 4, characterized in that, said first wedge (61a) and said second wedge (61b) comprise a predetermined wedge angle (V) therebetween with at least one first axis (I).

6. A vibration isolation system (10) according to claim 4 and 5, characterized in that, the wedge angles (V) of the first wedge (61a) and second wedge (61b) are equal to each other.

7. A vibration isolation system (10) according to claim 4 and 5, characterized in that, the first wedge (61a) and second wedge (61b) are at equal distance from the axis (IV) in the middle.

8. A vibration isolation system (10) according to claim 1 , characterized in that, the lever guiding element (60) comprises at least one mass (62) and said mass (62) is positioned on the first region (20) by means of an elastic element such as at least one spring (63).

9. A vibration isolation system (10) according to claim 8, characterized in that, the stiffness of an elastic element such as a spring (63) is low and the mass (62) to which it is connected is large so that the natural frequency of the mass (62) is below the vibration isolation frequency range.

10. A vibration isolation system (10) according to claim 1 , characterized in that, the lever guiding element (60) guides the lever along the first axis (I) in either direction when the lever is disturbed externally or the input excitation frequency changes in order to bring the instantaneous center of rotation (II) to coincide with the second hinge element (31).

11. A vibration isolation system (10) according to claim 1 , characterized in that, the lever guiding element (60) is a mechanical system that does not require any electronic sensors, actuators or control circuits for the self-tuning operation.

12. A vibration isolation system (10) according to claim 1 , characterized in that, the lever guiding element (60) is a self-powered system that is powered by the input vibration coming from the first region (20) which eliminates the need for electrical energy input for the self-tuning operation.

Description:
A VIBRATION ISOLATION SYSTEM

TECHNICAL FIELD

The invention relates to at least one vibration isolation system particularly for use in vibration isolation, comprising mainly at least one first region and at least one second region that are positioned mutually, at least one first hinge member engaged with said first region, at least one second hinge member engaged with said second region and at least one lever connected with said first hinge member and said second hinge member to be at least partially movable in the direction of at least one first axis.

PRIOR ART

Vibration is a term that defines the oscillation movements of a mechanical system or structure about an equilibrium point. During vibrations, energy is alternated between kinetic and potential forms to create the observed oscillations.

Vibrational motion is characterized by its frequency and amplitude. Vibration is generally undesirable since it wastes energy, leads to fatigue failure or structural damage and creates undesired sound and noise.

Free vibration is a type of vibration that occurs in the systems to which an initial motion is provided and is released for oscillation. Forced vibration is a vibration type that occurs when a variable force or motion is applied to excite a mechanical system. The frequency of the vibrational motion depends on the frequency of the applied force or motion in forced vibration; however, the amplitude of the vibration depends both on the mechanical properties of the system and the amplitude of the input force.

Vibrations occur due to various reasons, but in general the vibration sources create negative effects on the structures to which they are connected. It is important to isolate vibrations caused by mechanical, electro-mechanical, pneumatic or hydraulic equipment where comfort is a major consideration. Likewise, vibration isolation is important for preventing mechanical damage due to fatigue. Vibration absorbers are used to prevent vibrations in narrow frequency ranges. This type of passive systems does not operate effectively outside the frequency range to which they are adjusted (tuned). The prevention of vibrations within a wide frequency range can be provided by active or semi-active (adaptive) systems. These types of systems change the system parameters or generate control forces by monitoring the input and/or output vibrations. Accordingly, electronic control equipment such as sensor, actuator, control circuit, PLC or computer etc. is used in these systems. However, due to the presence of these components, the system becomes complicated. The production of these systems is rather complicated and results in costly products. Moreover, external electrical energy input is used by the electronic equipment within these systems. Therefore, electrical line, power supply or batteries are required.

As a result, all abovementioned problems have made it necessary to make an improvement in the relevant technical field.

SUMMARY OF THE INVENTION

The present invention is related to a self-tuning and self-powered mechanical vibration isolation system to eliminate the abovementioned disadvantages and to bring new advantages to the relevant technical field.

An object of the invention is to provide a vibration isolation system with improved vibration isolation performance.

Another object of the invention is to provide a mechanical vibration isolation system that does not require any electronic sensors, actuators or control circuits for the self-tuning operation.

Another object of the invention is to provide a self-powered vibration isolation system that is powered by the input vibration which eliminates the need for electrical energy input for the self-tuning operation.

In order to achieve all of the abovementioned objects that will be understood from the following detailed description, the present invention is at least one vibration isolation system to be used particularly in vibration isolation, comprising mainly at least one first region and at least one second region that are positioned mutually, at least one first hinge member engaged with said first region, at least one second hinge member engaged with said second region and at least one lever connected with said first hinge member and said second hinge member to be at least partially movable in the direction of at least one first axis. Accordingly, the novelty herein is that at least one lever guiding element is positioned to minimize vibration transmission between the first region and the second region and said lever guiding element is configured to align an instantaneous center of rotation (instantaneous center of zero velocity) on said lever depending on the vibration frequency. The vibration source is in the first region and it is aimed to provide vibration isolation in the second region. Vibrations received from the first region to the lever slide the lever with respect to the hinges along one first axis and bring the instantaneous center of rotation under the second hinge that is connected to the second region which will be subjected to vibration isolation. Therefore, the vibration transmission between the first region and the second region is minimized.

Another possible embodiment of the invention is characterized in that the lever guiding element includes at least one wedge, pad or fin so as to contact the lever. Therefore, the vibration energy is used to control the vibration by contacting the lever with at least one wedge, pad or fin having elastic features.

Another possible embodiment of the invention is characterized in that said wedge is positioned to be aligned with the second hinge connected to the second region which is required to be isolated from vibration. Therefore, it is provided that the instantaneous center of rotation of the lever comes to the same point with this hinge.

Another possible embodiment of the invention is characterized in that said wedge comprises at least one first wedge and at least one second wedge. Therefore, the bidirectional movement of the lever in the first axis is provided by two wedges.

Another possible embodiment of the invention is characterized in that said first wedge and said second wedge make a predetermined wedge angle with at least one first axis. Therefore, the proportional control of the force to be formed by the lever that impacts the wedge and the formation of a component in the direction of the axis of the lever is provided.

Another possible embodiment of the invention is characterized in that the wedge angles of the first wedge and the second wedge are equal to each other. Another possible embodiment of the invention is characterized in that the lever guiding element comprises at least one mass and the first and second wedges are positioned at equal distances from the central point of this mass.

Another possible embodiment of the invention is characterized in that the mass that carries the wedges is positioned on the vibration source (first region) by means of at least one elastic element such as a spring. The stiffness of this spring or elastic element is selected to be low and the natural frequency of the mass to which it is connected is provided to be well below the vibration isolation frequency range. Hence, the mass can be considered as an artificial ground mass. Therefore, the transmission of vibrations coming from the vibration source (first region) to the wedges is minimized.

The self-tuning vibration isolation system reaches the equilibrium position when the instantaneous center of zero velocity coincides with the second hinge member that is attached to the second region. At equilibrium position, the two wedges contact the lever at equal distances from the instantaneous center of zero velocity and create equal forces. Thus, the lever cannot move along the first axis. Moreover, at this position, antiresonance is achieved, hence vibration in the second region is minimized. If the lever is disturbed or the vibration frequency in the first region changes, then one of the wedges experiences higher vibration and that wedge generates a higher force and pushes the lever towards its side. As a result, the instantaneous center of zero velocity again coincides with the second hinge member that is attached to the second region and equilibrium is established.

The self-tuning vibration isolation system is also self-powered. The motion of the lever along the first axis is achieved by using the input vibrational energy coming from the first region. The wedges that are on the artificial ground mass use this input vibrational energy to tune the system. Moreover, the self-tuning action is achieved only by mechanical means (no electrical energy input or no electronic sensors, actuators or controllers).

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows an illustrative view of the transmissibility graph of an ordinary single- degree-of-freedom lever-type vibration isolation system.

In Figures 2a-2e self-tuning action is not considered so that the resonance frequency (f p ) and antiresonance frequency (f z ) remain unchanged when excitation frequency (f) is applied. Figure 2a shows an illustrative overlapped view of the motion created in case that a vibration below the resonance frequency (f < f p ) is applied to the lever-type vibration isolation system.

Figure 2b shows an illustrative overlapped view of the motion created in case that a vibration at the resonance frequency (f = f p ) is applied to the lever-type vibration isolation system.

Figure 2c shows an illustrative overlapped view of the motion created in case that a vibration at a frequency (f p < f < f z ) between resonance and antiresonance frequency is applied to the lever-type vibration isolation system.

Figure 2d shows an illustrative overlapped view of the motion created in case that a vibration at the antiresonance frequency (f = f z ) is applied to the lever-type vibration isolation system.

Figure 2e shows an illustrative overlapped view of the motion created in case that a vibration above the antiresonance frequency (f > f z ) is applied to the lever-type vibration isolation system.

Figure 3 shows an illustrative schematic view of the inventive vibration isolation system.

Figure 4 shows an illustrative schematic view of the wedges of the inventive vibration isolation system positioned below the lever.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject of the invention is described by way of examples only for clarifying the subject matter such that no limiting effect is created.

The invention relates to at least one vibration isolation system (10) for isolating vibrations at a predetermined region. In a possible embodiment of the invention, the inventive vibration isolation system (10) is a lever (50) type isolator and does not transmit the vibration that occurs on one side (first region (20)) to the other side (second region (30)). The vibration isolation element (10) can be used in all fields such as the transportation industry including preferably automotive, marine transportation, railway and aviation, household appliances, energy sector, military industry, and machinery industry where variable frequency mechanical vibrations are required to be isolated.

In Figure 3, an illustrative schematic view of the inventive vibration isolation system (10) is presented. Accordingly, the vibration isolation system (10) has at least one first region (20) and at least one second region (30). Said first region (20) is the place where there is vibration source and said second region (30) is the region which is to be protected from vibration.

There is at least one isolation element (70) positioned between the first region (20) and the second region (30). In a possible embodiment of the invention, said isolation element (70) is an elastically deformable member, and in another possible embodiment of the invention, it exhibits resilience properties. The function of the isolation element (70) is to support loads between the first region (20) and the second region (30) under static conditions and to isolate any vibrations that may occur at least partially.

At least one hinge element (21) is engaged with the first region (20) and at least one second hinge element (31) is engaged with the second region (30). At least one bearing (40) is positioned on the first hinge element (21) and the second hinge element (31) that face each other. Said bearing (40) is configured such that at least one lever (50) is positioned therein and said lever (50) is allowed to translate at least partially along at least one first axis (I). Said first axis (I) is normally the extension direction of the lever (50). The lever (50) is connected to the first hinge element (21) and the second hinge element (31) by means of the bearings (40). The lever (50) can move at least partially on the first axis (I) by sliding along the bearings (40). Moreover, the first hinge element (21) and the second hinge element (31) allow rotation of the lever with respect to the first region (20) and the second region (30). Hence, the lever (50) can rotate and translate. At least one mass (51) can be positioned on the tip of the lever (50). Said tip mass (51) is a predetermined amount, and contributes to the isolation effect of the system by lowering the resonance frequency of the assembly.

In case of vibration, the lever (50) rotates about an instantaneous center of rotation (II) with small movements by means of the bearings (40) and forms at least one rotation angle (III) on the first axis (I). The magnitude of said rotation angle (III) changes due to the amplitude of the vibration, and the position of said instantaneous center of rotation (II) depends on the vibration frequency. The object of the invention is to move the lever (50) between the first hinge element (21) and the second hinge element (31) on the first axis (I) to align the instantaneous center of rotation (II) with the second hinge element (31) which is attached to the second region (30). In that case, no vibration is transmitted to the second region (30) and perfect vibration isolation is achieved.

There is at least one lever guiding element (60) in the vibration isolation system (10) to move the lever (50) on the first axis (I). Said lever guiding element (60) aligns the instantaneous center of rotation (II) of the lever (50) with the second hinge element (31) in the second region (30) where vibration is not desired by resting on the lever (50) and providing forces along the first axis (I). In a possible embodiment of the invention, the lever guiding element (60), which is positioned against the second hinge element (31) located in the second region (30) where vibration is not desired, positions the instantaneous center of rotation (II) and the second hinge element (31) on at least one second axis (IV) by sliding the lever (50) through bearings (40). Said second axis (IV) passes through the middle of the second hinge element (31) and it is perpendicular to the second region (30).

In a possible embodiment of the invention, the lever guiding element (60) is positioned on the first region (20), which is the vibration source, along the direction of the second axis (IV), which is the direction along which vibration isolation is to be carried out. The lever guiding element (60) has at least one mass (62). At least one spring (63) is positioned on one side of the mass (62) and at least one wedge (61) is positioned on the other side of the same. Said spring (63) is in fact an elastic element and provides the engagement of the mass (62) with the first region (20). The stiffness of the spring (63) is determined such that the natural frequency of the mass (62) to which it is connected is provided to be well below the vibration isolation frequency range. The spring (63) prevents the mass (62) from being affected by vibration by means of isolating the vibrations coming from the first region (20) where the vibration source is present. In a possible embodiment of the invention, in addition to the spring (63), there is at least one damper (not shown) to operate together with the spring (63). Said damper provides the mass (62) to stay stationary by damping the vibrations coming from the base or caused by the lever hitting the wedges during the operation of the system. The mass (62) is preferably large and is provided to remain stationary without being affected by the vibrations that may occur in the first region (20). Said wedge (61) moves the lever (50) on the first axis (I) with respect to the vibration to which the lever (50) is exposed, thus provides the instantaneous center of rotation (II) to be positioned on the second axis (IV). In a possible embodiment of the invention, the wedge (61) is made of a rubber material such that it can absorb energy. The wedge (61) is configured to transmit vibration and impact forces. In Figure 4, an illustrative schematic view of the wedge (61) positioned in the inventive vibration isolation system (10) is presented. Accordingly, the wedge (61) comprises at least one first wedge (61a) and at least one second wedge (61b). Said first wedge (61a) and said second wedge (61b) are substantially configured to move the lever (50) in opposite directions on the first axis (I) by hitting the lever (50) during the oscillations of the lever (50). Thus, the first wedge (61a) and the second wedge (61b) are positioned to form at least one wedge angle (V) between them and the second axis (IV). Said wedge angle (V) allows the lever to move on the first axis (I) by hitting the first wedge (61a) or the second wedge (61b) as a consequence of vibration. In a possible embodiment of the invention, wedge angles (V) for the first wedge (61a) and the second wedge (61b) are equal to each other. The lever moves upon the vibration of the first region (20). The lever (50) impacts the first wedge (61a) and the second wedge (61b) simultaneously during its movement. Since the first wedge (61a) and the second wedge (61b) make a wedge angle (V) at the movement of impact, two opposite forces that are parallel to the first axis (I) in proportion to the impact speeds are applied by the wedges to the lever (61). Among these two opposite forces, the force where the lever (50) impacts with higher speed will be greater, so a net force that pushes the lever (50) in that direction occurs. Consequently, the lever (50) moves in the direction of the net force. When the instantaneous center of rotation (II) is aligned with the second axis (IV), the movement of the lever (50) in the first axis (I) is fixed because the speeds on the two wedges (61) are the same. Therefore, the second hinge element (31) aligns with the instantaneous center of rotation (II) and prevents the transmission of vibration to the second region (30).

In Figure 1 , an illustrative view of the transmissibility graph of a representative lever-type vibration isolation system (10) is presented. There is one resonance frequency (f p ) and one antiresonance frequency (f z ). Transmissibility is the ratio of output to input vibration amplitude. At resonance, transmissibility is very large and at antiresonance transmissibility is very low. Flere, there is no self-tuning action. Flence, the resonance frequency (f p ) and the antiresonance frequency (f z ) remain constant as the excitation frequency (f) changes.

In Figures 2a-2e, the lever guiding element (60) is not considered and hence the position of the instantaneous center of rotation remains fixed for a fixed excitation frequency (f). Flence, in Figures 2a-2e, self-tuning action is not considered.

In Figure 2a, an illustrative overlapped view of the motion created in case that a vibration below the resonance frequency (f < f p ) is applied to the lever-type vibration isolation system (10) is presented. In case that a vibration below the resonance frequency (f < f p ) is applied to the lever-type vibration isolation system (10) from the first region (20), the instantaneous center of rotation (II) is positioned outside the first hinge element (21) and the second hinge element (31).

In Figure 2b, an illustrative overlapped view of the motion created in case that a vibration at the resonance frequency (f = f p ) is applied to the lever-type vibration isolation system (10) is presented. Accordingly, in case that a vibration at the resonance frequency (f = f p ) is applied to the lever-type vibration isolation system (10) from the first region (20), the instantaneous center of rotation (II) coincides with the first hinge element (21).

In Figure 2c, an illustrative overlapped view of the motion created in case that a vibration at a frequency (f p < f < f z ) between resonance and antiresonance frequency is applied to the lever-type vibration isolation system (10) is presented. Accordingly, in case that a vibration at a frequency (f p < f < f z ) between resonance and antiresonance frequency is applied to the lever-type vibration isolation system (10) from the first region (20), the instantaneous center of rotation (II) is positioned between the first hinge element (21) and the second hinge element (31).

In Figure 2d, an illustrative overlapped view of the motion created in case that a vibration at the antiresonance frequency (f = f z ) is applied to the lever-type vibration isolation system (10) is presented. Accordingly, in case that a vibration at an antiresonance frequency (f = f z ) is applied to the lever-type vibration isolation system (10) from the first region (20), the instantaneous center of rotation (II) is aligned with the second hinge element (31) on the second axis (IV). Since the instantaneous center of rotation (II) is stationary, the second region (30) is prevented from vibrating.

In Figure 2e, an illustrative overlapped view of the motion created in case that a vibration above the antiresonance frequency (f > f z ) is applied to the lever-type vibration isolation system (10) is presented. In case that a vibration above the antiresonance frequency (f > f z ) is applied to the lever-type vibration isolation system (10) from the first region (20), the instantaneous center of rotation (II) is positioned outside the first hinge element (21) and the second hinge element (31).

When the lever guiding element (60) is used in the system, the resonance frequency (f p ) and the antiresonance frequency (f z ) change as a function of the lever position. The antiresonance frequency (f z ) of the system is brought to the excitation frequency (f) by moving the lever (50) in the direction of axis (I) with the forces created by the wedges regardless of the position of the instantaneous center of rotation (II), by means of mutual wedges (61a and 61b) operating oppositely. In this case, the instantaneous center of rotation comes under the second hinge (31) and the vibration transmitted to the second region (30) is minimized. In essence, the antiresonance frequency (f z ) of the vibration isolation system (10) tracks the input vibration frequency (f) and the vibration isolation system (10) always moves to the antiresonance condition even if the input excitation frequency (f) changes.

With this entire configuration, the vibrations are provided to be fully isolated (insulated) mechanically, by using energy of the mechanical vibrations (without external electrical energy input, power supply or battery, etc.) that shakes the vibration isolation system (10) as passive adaptive (not including electronic control equipment such as sensor, actuator, control circuit, PLC or computer etc.). Moreover, the vibration isolation system (10) provides a cheap and safe solution.

The protection scope of the invention is specified in the appended claims and cannot be limited to the description made for illustrative purposes in this detailed description. Likewise, it is clear that a person skilled in the art can present similar embodiments in the light of the above descriptions without departing from the main theme of the invention.

REFERENCE NUMBERS GIVEN IN THE FIGURE

10 Vibration Isolation System

20 First Region

21 First Hinge Element

30 Second Region

31 Second Hinge Element

40 Bearing

50 Lever

51 Tip Mass

60 Lever Guiding Element

61 Wedge 61a First Wedge 61b Second Wedge

62 Mass

63 Spring

70 Isolation Element

(I) First Axis

(II) Instantaneous Center of Rotation (III) Rotation Angle

(IV) Second Axis

(V) Wedge Angle