Negative stiffness particle damper

Abstract

The present invention relates to the field of vibration control technology, and provides a negative stiffness particle damper, which includes a first connecting member, a second connecting member, an impeller assembly and a lead screw transmission assembly; the second connecting member is movably arranged on the first connecting member along the vibration direction, a cavity is arranged in the first connecting member, and the cavity is used for filling particles; the lead screw transmission assembly includes a lead screw and a nut, one end of the lead screw is connected to the impeller assembly, the other end of the lead screw extends along the vibration direction, the nut is sleeved on the lead screw, and the nut is connected to the second connecting member; when the first connecting member and the second connecting member move relative to each other, the second connecting member is used to drive the impeller assembly to rotate through the lead screw transmission assembly so as to stir the particles in the cavity; the present invention converts the vibration in the linear direction into the rotation of the impeller assembly through the lead screw transmission assembly, thereby stirring the particles in the cavity, avoiding the stacking of particles, amplifying the resistance of stirring the particles, fully consuming the vibration energy, and improving the vibration reduction effect.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration control, and in particular, to a negative stiffness particle damper. Background Art

[0002] Structures will vibrate under the action of dynamic loads. Excessive vibration responses will affect the comfort of the structures, reduce the service performance of the structures, and even lead to component failure or structural damage. Therefore, good and effective vibration control means are needed to ensure the safety and reliability of the structures; installing dampers on the structures is one of the commonly used vibration control means in the engineering field.

[0003] The damper includes a particle damper. Existing particle dampers have the problem that the vibration reduction effect of the particle damper is poor due to particle stacking. Summary of the Invention

[0004] The present invention provides a negative stiffness particle damper to solve or improve the problem that the existing particle damper has poor vibration reduction effect due to particle stacking.

[0005] The present invention provides a negative stiffness particle damper, including: a first connecting member, a second connecting member, an impeller assembly and a lead screw drive assembly; the second connecting member is movably arranged on the first connecting member along the vibration direction, a cavity is arranged in the first connecting member, and the cavity is used for filling particles; the lead screw drive assembly includes a lead screw and a nut, one end of the lead screw is connected to the impeller assembly, the other end of the lead screw extends along the vibration direction, the nut is sleeved on the lead screw, and the nut is connected to the second connecting member; when the first connecting member and the second connecting member move relative to each other, the second connecting member is used to drive the impeller assembly to rotate through the lead screw drive assembly to stir the particles in the cavity.

[0006] According to a negative stiffness particle damper provided by the present invention, the first connecting member includes: a first section and a second section; the cavity is formed in the first section, and the first section and the second section are arranged along the vibration direction; both the second section and the second connecting member are cylindrical, the second section is sleeved on the second connecting member, one end of the lead screw extends into the second section and is connected to the impeller assembly, and the other end of the lead screw extends into the second connecting member.

[0007] According to a negative stiffness particle damper provided by the present invention, the impeller assembly includes: blades and a rotating shaft; the blades are arranged in the cavity, the rotating shaft extends along the vibration direction, and the rotating shaft is rotatably connected to the first section; the blades are connected to one end of the rotating shaft, and the other end of the rotating shaft extends into the second section and is connected to one end of the lead screw.

[0008] According to a negative stiffness particle damper provided by the present invention, the impeller assembly further includes: a first clamping arm and a second clamping arm; the first clamping arm and the second clamping arm are oppositely arranged along the axial direction of the rotating shaft, and two ends of the blade are respectively connected to the first clamping arm and the second clamping arm.

[0009] According to a negative stiffness particle damper provided by the present invention, a gap is provided between one side of the blade close to the rotating shaft and the outer side wall of the rotating shaft.

[0010] According to a negative stiffness particle damper provided by the present invention, a plurality of blades are provided, and the plurality of blades are arranged circumferentially along the rotating shaft.

[0011] According to a negative stiffness particle damper provided by the present invention, a limiting portion is provided at the other end of the lead screw, and the limiting portion is used to stop the nut.

[0012] According to a negative stiffness particle damper provided by the present invention, the nut is arranged in the second connecting member, and the nut is detachably connected to the inner side wall of the second connecting member.

[0013] According to a negative stiffness particle damper provided by the present invention, the cross-sectional shape of the cavity in a plane perpendicular to the axis of the lead screw is circular.

[0014] According to a negative stiffness particle damper provided by the present invention, a first connecting portion is provided at one end of the first connecting member facing away from the second connecting member, and a second connecting portion is provided at one end of the second connecting member facing away from the first connecting member. The first connecting portion is used to connect to one of the two connection points that vibrate relatively in the vibration structure, and the second connecting portion is used to connect to the other of the two connection points.

[0015] The negative stiffness particle damper provided by the present invention converts the vibration in the linear direction into the rotation of the impeller assembly through the lead screw transmission assembly, thereby agitating the particles in the cavity to fully consume the vibration energy, and further achieving the purpose of reducing the vibration response.

[0016] When vibration reduction is required for a vibrating structure, connect the first connecting member to one of the two connection points that vibrate relative to each other in the vibrating structure, and connect the second connecting member to the other of the two connection points. When the vibrating structure vibrates, relative movement occurs between the two connection points, cycling between a state of approaching and a state of moving away from each other. This drives a reciprocating linear motion between the first connecting member and the second connecting member. Then the nut reciprocates on the lead screw, further driving the lead screw to switch between a forward rotation state and a reverse rotation state. When the direction of the movement between the first connecting member and the second connecting member driven by vibration changes, the rotation direction of the impeller assembly also changes. However, at this time, the impeller assembly and the particles in the cavity still rotate in the original rotation direction, thus hindering the change in the movement direction between the first connecting member and the second connecting member, that is, the movement direction of the first connecting member and the second connecting member is too late to change. Therefore, this negative stiffness particle damper will produce a negative stiffness effect. It can be understood that the relative movement between the first connecting member and the second connecting member has a lagging effect compared to the vibration response, thereby offsetting the vibration response to achieve the purpose of vibration reduction. At the same time, during the rotation of the impeller assembly, the particles in the cavity can be agitated, causing effective collisions and frictions between the particles in the cavity and between the particles and the cavity, and avoiding the phenomenon of particle stacking, improving the energy dissipation capacity of this negative stiffness particle damper. Secondly, through the lead screw transmission assembly, the resistance received by the impeller assembly when agitating the particles in the cavity is amplified, thus effectively amplifying the control force of this negative stiffness particle damper, correspondingly improving the energy dissipation capacity, further reducing the vibration response of the vibrating structure, and having good adaptability without being limited by the engineering space. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 is a schematic structural diagram of the negative stiffness particle damper provided by the present invention;

[0019] Figure 2 is Figure 1 a cross-sectional structural diagram in the A-A direction;

[0020] Reference numerals:

[0021] 1: First connecting piece; 11: First section; 12: Second section; 2: Second connecting piece; 3: Impeller assembly; 31: Blade; 32: Rotating shaft; 33: First clamping arm; 34: Second clamping arm; 4: Lead screw drive assembly; 41: Lead screw; 42: Nut; 43: Limiting part; 5: Particle; 6: Coupling; 7: Bearing; 81: Fixing bolt; 82: Bolt; 91: First connecting part; 92: Second connecting part. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0024] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0025] The applicant found during the R & D process that the following problems still exist in the existing particle dampers during use.

[0026] For a single-particle damper, the large particle size of the particles makes it difficult to start vibration, and the large particles are limited by the engineering space, resulting in poor adaptability and vibration reduction performance.

[0027] For a multi-particle damper, due to the large number of particles, the particles are prone to stacking, resulting in effective actual energy consumption capacity, and thus good vibration reduction performance cannot be obtained.

[0028] For a particle tuned mass damper, a relatively large mass ratio is usually required to obtain a better vibration damping effect, resulting in poor feasibility and adaptability.

[0029] The following will Figures 1 to 2 describe a negative stiffness particle damper provided by the present invention.

[0030] As Figure 1 and Figure 2 shown, the negative stiffness particle damper shown in this embodiment includes: a first connector 1, a second connector 2, an impeller assembly 3 and a lead screw drive assembly 4.

[0031] The second connector 2 is movably arranged on the first connector 1 along the vibration direction. A cavity is provided in the first connector 1, and the cavity is used to fill particles 5. The lead screw drive assembly 4 includes a lead screw 41 and a nut 42. One end of the lead screw 41 is connected to the impeller assembly 3, and the other end of the lead screw 41 extends along the vibration direction. The nut 42 is sleeved on the lead screw 41, and the nut 42 is connected to the second connector 2. When the first connector 1 and the second connector 2 move relative to each other, the second connector 2 is used to drive the impeller assembly 3 to rotate through the lead screw drive assembly 4 to stir the particles 5 in the cavity.

[0032] Specifically, for the negative stiffness particle damper shown in this embodiment, the lead screw drive assembly 4 converts the vibration in the linear direction into the rotation of the impeller assembly 3, thereby stirring the particles 5 in the cavity to fully consume the vibration energy, and further achieving the purpose of reducing the vibration response.

[0033] When vibration reduction is required for a vibrating structure, the first connecting member 1 is connected to one of the two connecting points that vibrate relative to each other in the vibrating structure, and the second connecting member 2 is connected to the other of the two connecting points. When the vibrating structure vibrates, relative movement occurs between the two connecting points, and the two connecting points cycle between a state of approaching each other and a state of moving away from each other, thereby driving a reciprocating linear motion between the first connecting member 1 and the second connecting member 2. Then, the nut 42 reciprocates on the lead screw 41, further driving the lead screw 41 to switch between a forward rotation state and a reverse rotation state. When the direction of the motion between the first connecting member 1 and the second connecting member 2 driven by vibration changes, the rotation direction of the impeller assembly 3 also needs to change. However, at this time, the impeller assembly 3 and the particles 5 in the cavity still rotate in the original rotation direction, thereby hindering the change in the motion direction between the first connecting member 1 and the second connecting member 2, that is, the motion direction of the first connecting member 1 and the second connecting member 2 is too late to change. Therefore, this negative stiffness particle damper will produce a negative stiffness effect. It can be understood that the relative motion between the first connecting member 1 and the second connecting member 2 has a lagging effect compared to the vibration response, thereby offsetting the vibration response to achieve the purpose of vibration reduction. At the same time, during the rotation of the impeller assembly 3, the particles 5 in the cavity can be agitated, causing effective collisions and frictions between the particles 5 in the cavity and between the particles 5 and the cavity, and avoiding the phenomenon of particle 5 stacking, improving the energy dissipation capacity of this negative stiffness particle damper. Secondly, the resistance received by the impeller assembly 3 agitating the particles 5 in the cavity is amplified through the lead screw transmission assembly 4, thereby effectively amplifying the control force of this negative stiffness particle damper, correspondingly improving the energy dissipation capacity, further reducing the vibration response of the vibrating structure, and having good adaptability and not being limited by the engineering space.

[0034] It should be noted that the vibration direction shown in this embodiment is Figure 1 the left-right direction in; the particles 5 include particulate substances such as sand or lead pellets.

[0035] In some embodiments, as Figure 1 shown, the first connecting member 1 shown in this embodiment includes: a first section 11 and a second section 12; a cavity is formed in the first section 11, and the first section 11 and the second section 12 are arranged along the vibration direction; both the second section 12 and the second connecting member 2 are cylindrical, the second section 12 is sleeved on the second connecting member 2, one end of the lead screw 41 extends into the second section 12 and is connected to the impeller assembly 3, and the other end of the lead screw 41 extends into the second connecting member 2.

[0036] Specifically, both the second section 12 and the second connecting member 2 are arranged in a cylindrical shape. During the movement of the second connecting member 2 within the second section 12, the second section 12 plays a guiding role for the second connecting member 2, ensuring the stability of the lead screw drive assembly 4. At the same time, the lead screw 41 is arranged within the second connecting member 2, and the second connecting member 2 plays a protective role for the lead screw 41, ensuring the reliability of the lead screw drive assembly 4.

[0037] In some embodiments, as Figure 1 and Figure 2 shown, the impeller assembly 3 shown in this embodiment includes: a blade 31 and a rotating shaft 32; the blade 31 is arranged within the cavity, the rotating shaft 32 extends along the vibration direction, and the rotating shaft 32 is rotatably connected to the first section 11; the blade 31 is connected to one end of the rotating shaft 32, and the other end of the rotating shaft 32 extends into the second section 12 and is connected to one end of the lead screw 41.

[0038] Specifically, one end of the rotating shaft 32 extends into the cavity and is connected to the blade 31, and the other end of the rotating shaft 32 passes through the through hole on the first section 11 and extends into the second section 12, and is connected to one end of the lead screw 41 through a coupling 6. Among them, a bearing 7 is arranged between the through hole and the rotating shaft 32; in the case of relative movement between the first connecting member 1 and the second connecting member 2, the nut 42 on the second connecting member 2 moves on the lead screw 41, thereby driving the lead screw 41 to rotate, and the lead screw 41 drives the rotating shaft 32 to rotate synchronously through the coupling 6, so that the blade 31 can stir the particles 5 within the cavity.

[0039] In some embodiments, as Figure 1 shown, the impeller assembly 3 shown in this embodiment further includes: a first clamping arm 33 and a second clamping arm 34; the first clamping arm 33 and the second clamping arm 34 are arranged opposite to each other along the axial direction of the rotating shaft 32, and both ends of the blade 31 are respectively connected to the first clamping arm 33 and the second clamping arm 34.

[0040] Specifically, the blade 31 extends along the axial direction of the rotating shaft 32. The first clamping arm 33 is connected to the blade 31 through a fixing bolt 81, and the second clamping arm 34 is connected to the blade 31 through a fixing bolt 81. The blade 31 is fixed by the first clamping arm 33 and the second clamping arm 34, improving the stability of the blade 31, ensuring the strength of the blade 31, and further ensuring the stirring effect of the particles 5.

[0041] In some embodiments, as Figure 1 shown, there is a gap between the side of the blade 31 close to the rotating shaft 32 and the outer side wall of the rotating shaft 32.

[0042] Specifically, by setting a gap between the blade 31 and the rotating shaft 32, during the rotation of the rotating shaft 32, the particles 5 can pass through the gap, so that the particles 5 can be fully agitated, avoiding the stacking phenomenon of the particles 5, thereby improving the damping force of the negative stiffness particle damper, and the direction of the damping force is the axial direction of the rotating shaft 32.

[0043] During the R & D process, the applicant calculated the damping force F, and the calculation formula of the damping force F is as follows:

[0044]

[0045] Wherein, L is the lead of the lead screw 41, and T is the damping torque.

[0046] Generally, the range of the lead L is small, from 0.02 m to 0.1 m. Substituting it into the above formula, it can be obtained that the damping force F can be amplified by dozens to hundreds of times of the damping torque T. Under the action of the damping force F, the first connecting member 1 and the second connecting member 2 can effectively cancel the vibration to reduce the vibration response.

[0047] Furthermore, the applicant calculated the negative stiffness K n of the negative stiffness particle damper, and the calculation formula of the negative stiffness K n is as follows:

[0048]

[0049] Wherein, ω is the excitation frequency of the vibration, L is the lead of the lead screw 41, and I is the total moment of inertia of the blade 31, the rotating shaft 32, the first clamping arm 33, the second clamping arm 34 and the part of the particles being agitated.

[0050] From the calculation formula of the negative stiffness K n , it can be seen that when the excitation frequency ω remains unchanged, the total moment of inertia I and the lead L of the lead screw can be changed, so as to change the magnitude of the negative stiffness K n , and further meet different vibration reduction requirements.

[0051] In some embodiments, as Figure 2 shown, a plurality of the blades 31 shown in this embodiment are provided, and the plurality of blades 31 are arranged circumferentially along the rotating shaft 32. Correspondingly, a plurality of the first clamping arms 33 and the second clamping arms 34 are also provided in one-to-one correspondence; by providing a plurality of blades 31, while fully agitating the particles 5 in the cavity, the stability of the rotation of the impeller assembly 3 is ensured.

[0052] In some embodiments, as Figure 1As shown, a limiting portion 43 is provided at the other end of the lead screw 41 shown in this embodiment. The limiting portion 43 is used to stop the nut 42 to prevent the nut 42 from screwing out of the lead screw 41 when the first connecting member 1 and the second connecting member 2 move away from each other, thereby ensuring the reliability of the lead screw transmission assembly 4.

[0053] In some embodiments, as Figure 1 shown, the nut 42 shown in this embodiment is disposed inside the second connecting member 2, and the nut 42 is detachably connected to the inner side wall of the second connecting member 2.

[0054] Specifically, the nut 42 is fixed to the second connecting member 2 by bolts 82, ensuring the connection strength between the nut 42 and the second connecting member 2, and further ensuring the reliability of the lead screw transmission assembly 4.

[0055] In some embodiments, as Figure 2 shown, the cross-sectional shape of the cavity shown in this embodiment in a plane perpendicular to the axis of the lead screw 41 is circular.

[0056] Specifically, the entire cavity is cylindrical, so that the distribution of the particles 5 in the cavity is relatively uniform. At the same time, the rotating shaft 32 coincides with the axis of the cavity. During the rotation of the rotating shaft 32, the blades 31 can fully stir the particles 5 in the cavity to avoid the stacking phenomenon of the particles 5 caused by the stirring blind area, thereby improving the vibration damping effect of the negative stiffness particle damper.

[0057] In some embodiments, as Figure 1 shown, a first connecting portion 91 is provided at one end of the first connecting member 1 facing away from the second connecting member 2, and a second connecting portion 92 is provided at one end of the second connecting member 2 facing away from the first connecting member 1. The first connecting portion 91 is used to connect to one of the two connection points that vibrate relatively in the vibration structure, and the second connecting portion 92 is used to connect to the other of the two connection points.

[0058] Specifically, when it is necessary to reduce vibration at two opposite connection points on a vibrating structure, one connection point is connected to the first connection part 91, and the other connection point is connected to the second connection part 92, so as to realize that the two connection points are connected by a negative stiffness particle damper. When vibration occurs between the two connection points, the first connecting member 1 makes a reciprocating linear motion relative to the second connecting member 2, thereby driving the blade 31 to stir the particles 5 in the cavity through the lead screw transmission assembly 4, making the particles 5 collide and rub more effectively, improving the energy dissipation capacity of the negative stiffness particle damper, and at the same time avoiding the problem of particle 5 stacking; secondly, the resistance received by the particles 5 stirred by the blade 31 in the cavity is amplified by dozens to hundreds of times through the lead screw transmission assembly 4, effectively amplifying the control force of the negative stiffness particle damper, correspondingly improving the energy dissipation capacity, and further reducing the mass and size of the negative stiffness particle damper; at the same time, the negative stiffness particle damper has an obvious negative stiffness effect, which can further improve the energy dissipation capacity.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A negative stiffness particle damper, characterized in that, Comprising: A first connecting member, a second connecting member, an impeller assembly and a lead screw drive assembly; The second connecting member is movably disposed on the first connecting member along the vibration direction. A cavity is provided in the first connecting member, and the cavity is for filling particles; The lead screw drive assembly includes a lead screw and a nut. One end of the lead screw is connected to the impeller assembly, and the other end of the lead screw extends along the vibration direction. The nut is sleeved on the lead screw, and the nut is connected to the second connecting member; When the first connecting member and the second connecting member move relative to each other, the second connecting member is used to drive the impeller assembly to rotate through the lead screw drive assembly so as to agitate the particles in the cavity; The impeller assembly includes blades, a rotating shaft, a first clamping arm and a second clamping arm; the first clamping arm and the second clamping arm are oppositely arranged along the axial direction of the rotating shaft, and two ends of the blade are respectively connected to the first clamping arm and the second clamping arm; a gap is provided between one side of the blade close to the rotating shaft and the outer side wall of the rotating shaft so that particles can pass through the gap during the rotation of the rotating shaft; Among them, the negative stiffness K of the negative stiffness particle damper n is characterized by the following calculation formula: In the formula, ω is the excitation frequency of vibration, L is the lead of the lead screw, and I is the total moment of inertia of the blades, the rotating shaft, the first clamping arm, the second clamping arm and the part of the particles being agitated.

2. The negative stiffness particle damper according to claim 1, wherein The first connecting member includes: a first section and a second section; The cavity is formed in the first section, and the first section and the second section are arranged along the vibration direction; both the second section and the second connecting member are cylindrical, the second section is sleeved on the second connecting member, one end of the lead screw extends into the second section and is connected to the impeller assembly, and the other end of the lead screw extends into the second connecting member.

3. The negative stiffness particle damper according to claim 2, wherein The blades are arranged in the cavity, the rotating shaft extends along the vibration direction, and the rotating shaft is rotatably connected to the first section; the blades are connected to one end of the rotating shaft, and the other end of the rotating shaft extends into the second section and is connected to one end of the lead screw.

4. The negative stiffness particle damper according to claim 3, wherein There are a plurality of the blades, and the plurality of blades are arranged circumferentially along the rotating shaft.

5. The negative stiffness particle damper according to claim 2, wherein A limiting portion is provided at the other end of the lead screw, and the limiting portion is used to stop the nut.

6. The negative stiffness particle damper according to claim 2, wherein The nut is arranged in the second connecting member, and the nut is detachably connected to the inner side wall of the second connecting member.

7. The negative stiffness particle damper according to claim 1, wherein The cross-sectional shape of the cavity in a plane perpendicular to the axis of the lead screw is circular.

8. The negative stiffness particle damper according to any one of claims 1 to 7, wherein One end of the first connecting member facing away from the second connecting member is provided with a first connecting portion, and one end of the second connecting member facing away from the first connecting member is provided with a second connecting portion. The first connecting portion is used for connecting to one of the two connecting points that vibrate relative to each other in the vibration structure, and the second connecting portion is used for connecting to the other of the two connecting points.

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