An ultra-low frequency tuned mass damper

Abstract

The application relates to an ultra-low-frequency tuned mass inertia damper and relates to the technical field of damping vibration reduction devices. The damper comprises a fixed box and a damper arranged in the fixed box. The damper comprises a spring, a damping piece, a mass block and an inertia container. One end of the spring and the damping piece is fixed to the top of the fixed box. The mass block is fixedly connected to the other end of the spring and the damping piece and is rotatably connected to a rotating shaft. The inertia container comprises a rack, a flywheel and a gear. The rack is vertically fixed in the fixed box. The flywheel is sleeved and fixed to one end of the rotating shaft. The gear is sleeved and fixed to one end of the rotating shaft close to the flywheel. The gear is located on the side of the rack and can be engaged with the rack. The mass block can move up and down under the driving of the spring and can drive the flywheel and the gear to move up and down through the rotating shaft. The gear can be engaged with the rack and drive the flywheel to rotate around the rotating shaft while moving up and down. The application can not only reduce the static elongation of the spring, but also reduce the frequency and initial friction, so that the ultra-low-frequency structure damping is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of damping devices, in particular to a super-low-frequency tuned mass inertia damper. BACKGROUND

[0002] For some buildings and bridge structures that cannot be installed with a direct damper in the grounding mode, a tuned mass damper (TMD) can be installed at the position with the maximum structural amplitude. Through the frequency tuning effect, the vibration of the structure causes a large vibration of the mass block in the TMD, and then the vibration energy of the structure is transferred to the damper, and the energy is dissipated by the damping energy dissipation device in the damper, so as to finally realize the vibration control effect of the structure. Engineering practice has proved that the use of TMD can effectively control the vibration of the structure, which is an effective vibration reduction measure.

[0003] However, when the controlled frequency of the structure is continuously reduced, although the use of TMD is still effective in theory, since the spring of the traditional TMD needs to balance the weight of the mass block and adjust the frequency, the static deformation of the spring is inversely proportional to the square of the frequency. For example, the controlled frequency of the main beam of a certain sea-crossing bridge is 0.25 Hz, and the static deformation of the spring is close to 4 m, while the available space inside the box girder is about 3.5 m. Therefore, it is very difficult to achieve super-low frequency through the mechanical structure of the traditional TMD.

[0004] In related technologies, a ball screw type inertia mechanism is usually used to amplify the equivalent vibration mass of the tuned mass damper to solve the problem of excessive net elongation of the spring of the super-low-frequency vertical tuned mass damper. However, in the long-term use process of the ball screw type structure, there is friction between the ball and the ball, the ball and the slide, and the ball and the screw rod, and the multiple frictions increase the friction force, so that the initial damping ratio is too large. Since the damping coefficient of the super-low-frequency tuned mass damper is proportional to the frequency, the low frequency leads to a small damping coefficient, so the initial damping ratio of the super-low-frequency tuned mass damper needs to be small enough to obtain the optimal damping ratio through additional damping. Therefore, although the ball screw type inertia mechanism can solve the problem of excessive net elongation of the spring, it has the problem that the initial damping ratio is too large, so that the optimal damping ratio cannot be obtained. SUMMARY

[0005] The present application provides a super-low-frequency tuned mass inertia damper to solve the problem that the super-low-frequency structure cannot be effectively damped in related technologies.

[0006] In a first aspect, a super-low-frequency tuned mass inertia damper is provided, comprising:

[0007] a fixed box, configured to be fixed to a to-be-damped object;

[0008] A damper is arranged in the fixed box, and the damper comprises:

[0009] At least one spring, one end of the spring is fixed to the top of the fixed box;

[0010] A damping piece, one end of the damping piece is fixed to the top of the fixed box;

[0011] A mass block, the other end of the spring and the other end of the damping piece are fixedly connected to the mass block, and a rotating shaft is rotatably connected to the mass block;

[0012] At least one inertial container, the inertial container comprises:

[0013] A rack is vertically fixed in the fixed box;

[0014] A flywheel is fixedly sleeved on one end of the rotating shaft;

[0015] A gear is fixedly sleeved on one end of the rotating shaft close to the flywheel, the gear is located on the side of the rack and can engage with the rack;

[0016] Wherein, the mass block can move up and down under the driving of the spring and can drive the flywheel and the gear to move up and down through the rotating shaft, and the gear can engage with the rack and drive the flywheel to rotate around the rotating shaft while moving up and down.

[0017] In some embodiments, the bottom of the mass block is provided with a hanging ear plate on both sides, and the spring is fixedly connected to the mass block through the hanging ear plate.

[0018] In some embodiments, the number of springs is four, and the four springs are fixedly connected to the hanging ear plates on both sides of the mass block.

[0019] In some embodiments, the spring is a spiral tension spring.

[0020] In some embodiments, the rotation directions of two adjacent springs are opposite.

[0021] In some embodiments, the rotating shaft is arranged in the mass block and is rotatably connected to the mass block through a deep groove ball bearing.

[0022] In some embodiments, the number of inertial containers is two, and the two inertial containers are fixedly connected to both ends of the rotating shaft.

[0023] In some embodiments, the flywheel and the gear are fixed to the rotating shaft through a flat key.

[0024] In some embodiments, the fixed box is a hollow structure.

[0025] In some embodiments, the damping member is an eddy current damping or viscous damping.

[0026] The technical scheme provided by the application has the beneficial effects that not only the static elongation of the spring can be reduced, but also the frequency and initial friction can be effectively reduced, so that the super low frequency structure vibration reduction is realized.

[0027] The application provides a super low frequency tuned mass inertia damper, which comprises a fixed box and a damper arranged in the fixed box, wherein the damper comprises a spring, a damping member, a mass block and an inertia container. The spring and the damping member are fixed to the top of the fixed box at one end, the mass block is fixedly connected with the other end of the spring and the damping member, and a rotating shaft is rotatably connected to the mass block. The inertia container comprises a rack, a flywheel and a gear, the rack is vertically fixed in the fixed box, the flywheel is sleeved and fixed to one end of the rotating shaft, the gear is sleeved and fixed to one end of the rotating shaft close to the flywheel, the gear is located on the side of the rack and can be engaged with the rack, the mass block can move up and down under the driving of the spring and can drive the flywheel and the gear to move up and down through the rotating shaft, and the gear can move up and down while being engaged with the rack and driving the flywheel to rotate around the rotating shaft. When the damper is in a static state, the gear and the rack are not under force, that is, only the mass block and the flywheel participate in the static force balance operation, so that the dead weight in the static force balance equation is small, thereby effectively reducing the static elongation of the spring. When the damper works, the gear and the rack transmission will amplify the inertia coefficient generated by the flywheel, thereby reducing the frequency in the dynamic equation and achieving the purpose of super low frequency. In addition, since the initial friction damping in the application only comes from the gear-rack transmission and the rotating friction of the rotating shaft, the friction is small, thereby the initial friction is small, so that the optimal damping ratio is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Fig. 1 The application provides a super low frequency tuned mass inertia damper;

[0030] Fig. 2 The application provides a super low frequency tuned mass inertia damper;

[0031] Fig. 3 The application provides a super low frequency tuned mass inertia damper;

[0032] In the figure: 1 - fixed box, 2 - damper, 21 - spring, 22 - damping piece, 23 - mass block, 231 - rotating shaft, 232 - hanging ear plate, 24 - inertial container, 241 - rack, 242 - flywheel, 243 - gear. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0034] The embodiments of the present application provide an ultra-low frequency tuned mass inertial damper, which can solve the problem that an ultra-low frequency structure damping cannot be effectively realized in the related art.

[0035] Referring to Figs. 1 to 3 As shown in the figure, the embodiments of the present application provide an ultra-low frequency tuned mass inertial damper, which comprises a fixed box 1 and a damper 2. The fixed box 1 is used for being fixed on a to-be-damped object, and is preferably a hollow structure, which can effectively reduce the weight of the inertial damper. The damper 2 is arranged in the fixed box 1, and comprises at least one spring 21, a damping piece 22, a mass block 23 and at least one inertial container 24. The spring 21 is vertically arranged in the fixed box 1, and one end of the spring 21 is fixed to the top of the fixed box 1. The number of the springs 21 can be preferably an even number greater than 4, which can collectively provide balanced elastic force for the mass block 23, so that the mass block 23 can only vibrate up and down, and cannot be turned over or tilted. In addition, the spring 21 can be preferably a spiral tension spring, and the shape of the spiral tension spring can be preferably cylindrical. The spiral tension spring can not only provide stiffness for the damper, but also will not have instability problem in a large slenderness ratio (i.e. in a large stroke movement) compared with a compression spring. Furthermore, for the even number of springs 21, the rotation directions of the adjacent two springs 21 can be preferably set to be opposite, that is, a certain spring 21 is right-handed, and the adjacent spring 21 is left-handed, which can further avoid the problem that the mass block 23 swings left and right in the process of vibrating up and down.

[0036] The damping member 22 can be eddy current damping or viscous damping, one end of which is fixed to the top of the fixed box 1, when the mass block 23 moves relatively, the relative displacement occurs inside the damping member 22, thereby generating energy dissipation; the mass block 23 is fixedly connected with the other end of the spring 21 and the other end of the damping member 22, preferably, the bottom of the mass block 23 is provided with an ear plate 232, and a plurality of springs 21 can be preferably fixedly connected on the ear plate 232, since the ear plate 232 is arranged at the bottom of the mass block 23, a larger space is provided for the spring 21 to have a larger static deformation. In addition, the mass block 23 is rotatably connected with a rotating shaft 231, specifically, the mass block 23 is provided with a pin hole, the rotating shaft 231 penetrates through the pin hole and is rotatably connected with the mass block 23 through a deep groove ball bearing, so that the rotating shaft 231 can move synchronously up and down with the mass block 23, and can rotate around the axis.

[0037] The inertia container 24 includes a rack 241, a flywheel 242 and a gear 243, wherein the rack 241 is vertically arranged in the fixed box 1 and is fixedly connected with the top plate and the bottom plate of the fixed box 1; the flywheel 242 is sleeved and fixed to one end of the rotating shaft 231, and the gear 243 is sleeved and fixed to the end of the rotating shaft 231 close to the flywheel 242, wherein the flywheel 242 and the gear 243 are preferably fixed to the rotating shaft 231 through a flat key, and the fixing mode is more simple and efficient; the gear 243 is located at the side of the rack 241 and can engage with the rack 241; when the tuned mass damper works, the spring 21 will be stretched and compressed, and the mass block 23 will move up and down under the driving of the spring 21 and will drive the flywheel 242 and the gear 243 to move up and down through the rotating shaft 231, and the gear 243 will move up and down while engaging with the rack 241 and driving the flywheel 242 to rotate around the rotating shaft 231.

[0038] Further, the number of inertia containers 24 is preferably two, and the two inertia containers 24 are fixed to the two ends of the rotating shaft 231, so that the inertia force provided by the rotation of the flywheels 242 on both sides of the mass block 23 can make the mass block 23 move up and down smoothly.

[0039] In the static balance state, the gear 243 and the rack 241 are not under force, only the mass block 23 and the flywheel 242 participate in the static balance operation, the weight in the static balance equation is small, and thus the static elongation of the spring 21 is effectively reduced; when the damper works, the gear 243 and the rack 241 drive, the inertia coefficient generated by the flywheel 242 is amplified, and thus the frequency in the dynamic equation is reduced, the purpose of super low frequency is achieved; in addition, the initial frictional damping in the application only comes from the transmission of the gear 243 and the rack 241 and the rotational friction of the rotating shaft 231, so the friction is small, and thus the initial frictional resistance is small, and thus the optimal damping ratio is obtained.

[0040] The tuned mass inertia damper in the application is subjected to force analysis as follows:

[0041] When in the static balance state, the gear 243 and the rack 241 are not under force, the spring 21 only needs to balance the weight of the mass block 23 and the flywheel 242, and the balance equation is:

[0042] (m1+m2)·g=K·Δ (1)

[0043] In the formula, m1 is the mass of the mass block 23, m2 is the mass of the flywheel 242, g is the acceleration of gravity, K is the total stiffness of the spring 21, and Δ is the static elongation of the spring 21;

[0044] When in the non-static balance state, the mass block 23 moves up and down, the frequency of the tuned mass inertia damper is controlled by the stiffness of the spring 21, the inertia coefficient of the mass block 23 and the flywheel 242, and the dynamic equation is:

[0045]

[0046] In the formula, f is the frequency, K is the total stiffness of the spring 21, m e is the total inertia coefficient;

[0047] The equation (1) and the equation (2) have the following relationship:

[0048]

[0049] In the formula, m is the total mass, m e1 is the inertia coefficient of the mass block 23, m e2 is the inertia coefficient of the flywheel 242, and α is the conversion coefficient of the mass and the inertia coefficient of the flywheel 242.

[0050] Therefore, during the up-and-down movement of the spring 21, only the mass block 23 is in pure up-and-down movement, while the flywheel 242-rotation shaft 231-gear 243 is in rotation around the center of the rotation shaft 231 during the up-and-down movement of the mass block 23, and the rotation speed is related to the speed of the up-and-down movement and the radius of the gear 243. The rotation generates a rotational inertia force, and the inertia force is much larger than the transmission of the gear 243 and the gear rack 241, so that the inertia coefficient is much larger than the mass, and the frequency in the dynamic equation is reduced to achieve the purpose of super low frequency.

[0051] In addition, the initial frictional damping in the application mainly includes the rotational friction of the gear 243-gear rack 241 transmission and the bearing. First, when the gear 243-gear rack 241 is in static balance, the weight of the mass block 23 is directly balanced by the spring 21, and the weight of the flywheel 242 is transmitted to the spring 21 through the bearing, the rotation shaft 231 and the mass block 23 in turn, and there is no force between the gear 243 and the gear rack 241. Only during the vibration process, the gear 243 and the gear rack 241 generate a normal pressure, and the gear 243 can rotate, there is no sliding friction on the friction surface, and only a small contact surface is in contact at each moment, so the friction is small, and the initial frictional resistance is small, so that the optimal damping ratio can be obtained.

[0052] The following is an example of the design of the tuned mass inertia damper in the application:

[0053] It is known that the frequency f of a certain super low frequency tuned mass inertia damper is 0.25 Hz, the effective mass m is 1000 kg, the stroke S is ±600 mm, and the optimal damping ratio ξ is 4.3% = 4.3%. The spring 21 is a tension spring, the static elongation is controlled to be 800 mm, the total stiffness K of the four springs 21 is 1000 × 9.8 ÷ 0.8 = 12250 N / m, and the inertia mass Then the mass block 23 and the flywheel 242 are distributed according to formula (3), and the conversion coefficient between the mass of the flywheel 242 and the inertia coefficient is α. It can be known that m2 × (α-1) = 2958; combined with the actual structure design, m1 = m e1 = 802.8 kg, m2 = 197.2 kg, m e2 = 3158 kg, α = 16, that is, the transmission of the gear 243 and the gear rack 241 makes the flywheel with a mass of 197.2 kg generate an inertia coefficient of 3158 kg; finally, the damping coefficient C of the tuned mass inertia damper is calculated according to the above data C = 2 × 3958 × 2 × π × 0.25 × 4.3% = 535 N·s / m.

[0054] Therefore, when the application reaches the ultra-low frequency of 0.25 Hz, the static elongation of the tension spring is only 0.8 m, and the static elongation is mainly to ensure that the spring 21 always maintains good linearity during the vibration process of the amplitude of ±0.6 m; when the traditional TMD achieves the ultra-low frequency of 0.25 Hz, due to the lack of inertial mass amplification effect, the mass and the inertial mass coefficient are equal, so the static elongation of the tension spring is 3.97 m, therefore, the application can effectively reduce the static elongation of the spring 21 while achieving the ultra-low frequency. Of course, the embodiment is only an example of 0.25 Hz frequency to illustrate the design process of the ultra-low frequency tuned mass inertia damper in the application, if the frequency needs to be further reduced according to the actual demand, the application can still be achieved.

[0055] In the description of the application, it should be noted that the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. Unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0056] It should be noted that in the application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0057] The foregoing detailed description of the application has been presented for purposes of illustration and description. Various modifications and changes can be made to these embodiments without departing from the spirit and scope of the application. It is intended that the scope of the application should not be limited by the particular representative embodiments described above.

Claims

1. An ultra-low frequency tuned mass damper characterized by, The utility model relates to a damping device, including: A fixed box (1) is used for fixing on the object to be damped; A damper (2) is arranged in the fixed box (1), and the damper (2) comprises: At least one spring (21) is fixed to the top of the fixed box (1) on one end; A damping piece (22) is fixed to the top of the fixed box (1) on one end; A mass block (23) is fixedly connected with the other end of the spring (21) and the other end of the damping piece (22) respectively, and a rotating shaft (231) is rotatably connected to the mass block (23); At least one inertial container (24) comprises: A rack (241) is vertically fixed in the fixed box (1); A flywheel (242) is fixedly sleeved on one end of the rotating shaft (231); A gear (243) is fixedly sleeved on one end of the rotating shaft (231) close to the flywheel (242), and the gear (243) is located on the side of the rack (241) and can be engaged with the rack (241); Wherein, the mass block (23) can move up and down under the driving of the spring (21) and can drive the flywheel (242) and the gear (243) to move up and down through the rotating shaft (231), and the gear (243) can be engaged with the rack (241) and drive the flywheel (242) to rotate around the rotating shaft (231) while moving up and down; The number of the inertial container (24) is two, and the two inertial containers (24) are fixed on both ends of the rotating shaft (231) respectively; The rotating shaft (231) is arranged in the mass block (23) and is rotatably connected to the mass block (23) through a deep groove ball bearing; The bottom of the mass block (23) is provided with a hanging ear plate (232) on both sides, and the spring (21) is fixedly connected with the mass block (23) through the hanging ear plate (232).

2. The ultra-low frequency tuned mass damper of claim 1, wherein: The number of the spring (21) is four, and the four springs (21) are symmetrically fixedly connected to the hanging ear plates (232) on both sides of the mass block (23).

3. The ultra-low frequency tuned mass damper of claim 2, wherein: The spring (21) is a spiral tension spring.

4. The ultra-low frequency tuned mass damper of claim 3, wherein: The rotation directions of the adjacent two springs (21) are opposite.

5. The ultra-low frequency tuned mass damper of claim 1, wherein: The flywheel (242) and the gear (243) are fixed on the rotating shaft (231) through a flat key.

6. The ultra-low frequency tuned mass damper of claim 1, wherein: The fixed box (1) is a hollow structure.

7. The ultra-low frequency tuned mass-inertial damper of claim 1, wherein: The damping piece (22) is eddy current damping or viscous damping.

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