CN110965837A - Tuning type magnetic liquid rolling ball damper - Google Patents
Tuning type magnetic liquid rolling ball damper Download PDFInfo
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- CN110965837A CN110965837A CN201911344604.7A CN201911344604A CN110965837A CN 110965837 A CN110965837 A CN 110965837A CN 201911344604 A CN201911344604 A CN 201911344604A CN 110965837 A CN110965837 A CN 110965837A
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- 239000007788 liquid Substances 0.000 title claims abstract description 103
- 238000005096 rolling process Methods 0.000 title claims abstract description 58
- 239000003350 kerosene Substances 0.000 claims abstract description 25
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000010742 number 1 fuel oil Substances 0.000 claims abstract description 8
- 239000000463 material Substances 0.000 claims description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- 239000002105 nanoparticle Substances 0.000 claims description 4
- 239000011347 resin Substances 0.000 claims description 2
- 229920005989 resin Polymers 0.000 claims description 2
- 230000008901 benefit Effects 0.000 abstract description 6
- 230000009467 reduction Effects 0.000 description 23
- 230000008859 change Effects 0.000 description 9
- 239000010410 layer Substances 0.000 description 7
- 238000013016 damping Methods 0.000 description 6
- 238000013461 design Methods 0.000 description 5
- 230000004907 flux Effects 0.000 description 5
- 230000001133 acceleration Effects 0.000 description 4
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
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- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000010146 3D printing Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
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- 230000006872 improvement Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
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- 238000012423 maintenance Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
- E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
- E04B1/62—Insulation or other protection; Elements or use of specified material therefor
- E04B1/92—Protection against other undesired influences or dangers
- E04B1/98—Protection against other undesired influences or dangers against vibrations or shocks; against mechanical destruction, e.g. by air-raids
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
- E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
- E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
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Abstract
The invention relates to a tuning type magnetic liquid rolling ball damper. The damper comprises a cylindrical container with a hemispherical groove, a cylindrical solenoid coil, a horizontal base, a hollow rolling ball and kerosene-based magnetic liquid; the cylindrical solenoid coil is uniformly wound on the wall surface of the shell of the cylindrical container main body, the cylindrical container is positioned on the horizontal base, and the coal oil-based magnetic liquid is arranged in the hollow rolling ball; the hollow ball is within a hemispherical recess within the cylindrical container. The kerosene-based magnetic liquid is kerosene-based Fe3O4The volume of the magnetic liquid is 1/4-3/4 of the internal volume of the spherical shell. The invention has the advantages of simple structure, low cost, easy control and wide working frequency band.
Description
Technical Field
The invention relates to a damper, in particular to a tuned magnetic liquid rolling ball damper.
Background
Tuned dampers are widely used in a variety of high rise structures. The wind power tower is used as a high-rise structure, has the characteristics of being long, high, flexible, low in rigidity, easy to fatigue and the like, and can vibrate due to the influence of factors such as wind-induced load, earthquake load, power system disturbance and the like in the working process, wherein the vibration is one of important factors influencing the service life of a wind turbine generator. The phenomena of machine set blade broken lines, overlarge cabin amplitude, instability of a tower drum, generator faults and the like can be caused due to the vibration problem, so that the wind turbine cannot work normally, even the occurrence of tower falling accidents can be caused, and the great loss is caused. Therefore, the vibration control research of the wind power tower has important theoretical significance and engineering practical value. The patent aims to develop a device for reducing the vibration of the structure under the wind-induced load action from the two aspects of reducing the frequent vibration and responding of the wind power tower structure.
The existing tuned dampers mainly comprise tuned mass dampers, tuned liquid dampers, tuned rolling ball dampers and the like. The tuned mass damper is composed of a spring and a mass block, and the elastic coefficient of the spring and the mass of the mass block are changed to achieve the purpose of tuned vibration reduction; the tuned liquid damping is that a certain amount of liquid is filled in a rectangular or cylindrical container, and the purpose of tuned vibration reduction is achieved by changing the depth of the liquid; the tuned rolling ball damper is characterized in that a certain number of small balls are filled in a spherical container, and the purpose of tuned vibration reduction is achieved by changing the number and the radius of the small balls. The dampers usually change the spring coefficient and the mass of a mass block or change the depth and the viscosity of liquid to adjust the natural shaking frequency of the dampers and change the resonance characteristic of the whole structure, thereby achieving the effect of tuning damping vibration attenuation; most of the dampers have obvious effect on the natural frequency of the first vibration mode of the structure and narrow vibration reduction frequency band; when the disturbance of the external load is complex, the damping effect is obviously reduced, and the controllability is poor.
Disclosure of Invention
The invention aims to provide a tuning type magnetic liquid rolling ball damper aiming at the defects of the prior art. This attenuator combines together spin attenuator and harmonious formula magnetic liquid spin attenuator ingeniously, packs into magnetic liquid in the bobble, lets the bobble drive magnetic liquid and rolls together, not only can change the attenuator natural frequency through changing bobble and container radius, can also change the magnetic liquid through adjusting plus magnetic field and rock the frequency and change the attenuator natural frequency, consequently can realize the purpose of double-tuned damping. The invention has the advantages of simple structure, low cost, easy control and wide working frequency band.
The technical scheme of the invention is as follows:
a tuning type magnetic liquid rolling ball damper comprises a cylindrical container with a hemispherical groove inside, a cylindrical solenoid coil, a horizontal base, a hollow rolling ball and kerosene-based magnetic liquid; the cylindrical solenoid coil is uniformly wound on the wall surface of the shell of the cylindrical container main body, the cylindrical container is positioned on the horizontal base, and the coal oil-based magnetic liquid is arranged in the hollow rolling ball; the hollow ball is within a hemispherical recess within the cylindrical container.
The upper part of the cylindrical container is an open type hemispherical groove, the top of the groove is a convex shell upper edge, and the bottom of the cylindrical container is a convex horizontal base;
the hollow rolling ball is a hollow ball body; the top of the shell is provided with a screw hole provided with a threaded plug; the thickness of the spherical shell of the hollow rolling ball is 8-12 mm; the material is resin material.
The radius of the hollow rolling ball is 1/12-1/8 of the radius of the groove;
the cylindrical solenoid coil is a copper core enameled wire, 4-7 layers of solenoid coils are wound in total, and the rated current is 5A;
the kerosene-based magnetic liquid is kerosene-based Fe3O4Magnetic liquid with density of 1.36g/cm3(ii) a The ferroferric oxide is nano-particles, and the diameter range is 2-20 nm. The volume of the kerosene-based magnetic liquid is 1/4-3/4 of the internal volume of the spherical shell.
The horizontal base is evenly distributed with fixing screw holes along the circumference.
The diameter range of the cylindrical main body shell is 0.65-1.45 m, and the radius range of the internal hemispherical groove is 0.3-0.7 m.
The invention has the substantive characteristics that:
the invention researches and designs the geometric dimensions of the hemispherical container and the rolling ball according to the vibration strength and the frequency of the structure, the coal oil-based magnetic liquid is filled in the small ball, the magnetic-viscous characteristic of the magnetic liquid is combined, the external magnetic field is adjusted by changing the current led in by the solenoid coil, the viscosity of the magnetic liquid is changed, thereby adjusting the natural frequency of the damper, changing the resonance characteristic of the whole structure and achieving the purpose of self-adaptive variable frequency vibration control,
the invention has the beneficial effects that:
1. the invention overcomes the technical problem that the frequency of the traditional tuned liquid damper is uncontrollable, only the input current of the controllable current source is needed to be adjusted to control the natural frequency of the damper, the resonance characteristic of the structure is changed, the purpose of tuned vibration reduction is achieved, and the controllability is good.
2. At present, most of tuned dampers applied to high-rise structures at home and abroad can only achieve the effect of tuned vibration reduction on vibration within the range of 0.25Hz around the natural frequency of the structure, and the tuned vibration reduction device can perform tuned vibration reduction on vibration within the range of 0.32Hz around the natural frequency of the high-rise structure by adjusting an external magnetic field due to performance parameters such as the inertia viscosity of a rolling ball and magnetic liquid, and the like, so that the vibration reduction frequency bandwidth is increased by 0.14 Hz.
3. The invention can adjust the natural frequency of the damper by changing the radius of the small ball and the container and can also adjust the natural frequency of the damper by changing the shaking frequency of the magnetic liquid by changing the external magnetic field, thereby having the function of double-tuning vibration reduction.
4. The rolling ball drives the internal liquid to roll together, so that the liquid under the working condition is in a turbulent flow state, and tests prove that compared with the liquid in a fixed container in a shaking state, the liquid under the turbulent flow state has larger kinetic energy, namely the disturbance of the liquid is increased, so that the aim of increasing the energy consumption can be fulfilled; meanwhile, the friction between the small balls and the wall surface when the small balls roll can also increase the consumption of vibration energy.
5. The invention has simple structure and is formed by only combining a hollow rolling ball, a cylindrical container with a hemispherical groove in the cylindrical container, a cylindrical solenoid coil, a horizontal base and kerosene-based magnetic liquid; convenient processing, lower cost, convenient maintenance and high cost performance.
6. The invention can reduce the shaking of the structure in any horizontal direction, has the function of multi-directional vibration reduction, has stronger adaptability, can be suitable for high-rise building structures such as wind power generation towers, television towers and the like, has wide application range and can generate better economic benefit and social benefit.
Drawings
FIG. 1 is a schematic view of the overall appearance structure of a tuned magnetic liquid ball damper according to the present invention;
FIG. 2 is a schematic diagram of the whole cross-sectional structure of the tuned magnetic liquid ball damper of the present invention;
FIG. 3 is the whole sectional structure diagram of the cylindrical container with hemispherical concave groove inside of the tuned magnetic liquid rolling ball damper of the present invention;
FIG. 4 is a schematic diagram of a cylindrical solenoid coil winding structure of the tuned magnetic liquid ball damper of the present invention;
FIG. 5 is a schematic structural diagram of a hollow ball of the tuned magnetic liquid ball damper of the present invention;
FIG. 6 is a graph showing the variation of magnetic flux density along the sectional line of the hemispherical concave surface in the tuned magnetic liquid ball damper of the present invention.
In the figure, 1, a cylindrical container with a hemispherical groove therein, 2, a cylindrical solenoid coil, 3, a horizontal base, 4, a hollow rolling ball, 5, kerosene-based magnetic liquid, 1-1, the upper edge of the cylindrical container, 1-2, a cylindrical container main body shell, 1-3, the hemispherical groove, 2, the cylindrical solenoid coil, 3-1, a threaded hole in the horizontal base, 3-2, a cylindrical horizontal base, 4-1, a hollow spherical shell, 4-2, a threaded hole and 4-3, a threaded plug are arranged.
Detailed Description
Specific examples of the present invention are given below.
The tuning type magnetic liquid rolling ball damper is composed of a cylindrical container 1 with a hemispherical groove in the interior, a cylindrical solenoid coil 2, a horizontal base 3, a hollow rolling ball 4 and kerosene-based magnetic liquid 5, wherein the cylindrical container is provided with the hemispherical groove in the interior; the cylindrical solenoid coil 2 is uniformly wound on the wall surface of a main body shell of the cylindrical container 1, the cylindrical container 1 is positioned on the horizontal base 3, and the coal oil-based magnetic liquid 5 is arranged in the hollow rolling ball 4; the hollow ball 4 is within a hemispherical recess within the cylindrical vessel 1.
As shown in fig. 2, the upper part of the cylindrical container 1 is an open type semispherical groove 1-3, the top of the groove is a convex outer shell upper edge 1-1, and the bottom of the cylindrical container 1 is a convex horizontal base 3; the solenoid coil 2 is uniformly wound on the wall surface between the outer edge 1-1 of the outer shell 1-2 of the cylindrical container main body and the base 3 to form the outer shell structure of the whole damper; wherein, the diameter of the cylindrical container body shell 1-2 is 10cm larger than that of the hemispherical groove 1-3, and the height thereof is 20cm larger than that of the hemispherical groove.
The hollow rolling ball 4 can roll on the hemispherical groove surfaces 1-3 along any direction to drive the internal kerosene-based magnetic liquid 5 to roll together, and can damp and reduce vibration of the horizontal shaking in any direction.
The cylindrical container 1 and the base 3 are integrated, and can be cast and processed through a factory model or 3D printing and processing.
The hollow rolling ball 4 is a rollable thin-wall ball shell made of ABS resin material, and the wall thickness is 10mm, as shown in FIG. 5; the top of the shell is provided with a cylindrical threaded hole 4-2 with the diameter of about 8.5mm for containing kerosene-based magnetic liquid 5, and an ABS resin material threaded plug 4-3 with the corresponding type is assembled to ensure screwing and sealing, so that a closed spherical shell is formed and can roll in any direction on the hemispherical groove surface.
The relation between the radius of the hollow rolling ball and the radius of the hemispherical groove is as follows:
wherein f is the natural frequency of the damper system, and for the wind power tower, the frequency limit capable of damping is 1.37Hz, g is the gravitational acceleration, R is the radius of the hemispherical groove, and R is the radius of the hollow rolling ball.
The radius of the hollow rolling ball is 1/12-1/8 of the radius of the groove; the radius difference between the two can be calculated from the vibration reduction frequency, and then the mass of the damper and the volume of the magnetic liquid are determined according to the modal mass ratio of the damper and the vibration structure, so that the radius of the groove and the radius of the rolling ball can be determined.
The rolling ball cannot protrude out of the shell, and the radius of the rolling ball cannot exceed half of the groove through analysis and calculation1/8, the moving state of the ball is calculated by force analysis under the limit condition (the radius of the ball is 1/8 of the radius of the groove), and when the external given acceleration is 32m/s2The ball can rise to its highest, where it is spaced from the edge of the recess by 1/10 ball radii.
The cylindrical solenoid coil 2 is a copper core enameled wire, is tightly wound to a position 0.5-1.5 cm away from the outer edge of the upper part of the shell along the outer part 1-2 of the cylindrical container body from bottom to top in a single layer mode, is wound into a solenoid coil with 4-7 layers in total, has a rated current of 5A, and can generate an approximately uniform external magnetic field in the cylindrical container.
The kerosene-based magnetic liquid 5 is kerosene-based Fe3O4Magnetic liquid with density of 1.36g/cm3(ii) a The ferroferric oxide is nano-particles, and the diameter range is 2-20 nm. The coal oil-based magnetic liquid is not completely filled in the ball shell 4-1, the volume of the filled magnetic liquid is 1/4-3/4 of the internal volume of the ball shell, and the magnetic liquid rolls on the hemispherical groove surface 1-3 along with the ball in an approximately uniform external magnetic field.
The horizontal base 3 is a cylindrical horizontal base 3-2 as shown in fig. 3, and 3 threaded holes 3-1 are uniformly distributed along the circumference and used for fixing the damper on the vibration structure.
The design mechanism of the invention is as follows: according to the vibration intensity and frequency of the structure, the geometric dimensions of the container and the rolling ball are designed, the magnetic liquid is filled in the rolling ball, and when an external magnetic field acts on the magnetic liquid, the viscosity of the magnetic liquid can change along with the magnetic field, so that the inherent shaking frequency of the magnetic liquid can be changed by adjusting the external magnetic field, the inherent shaking frequency of the damping can be controlled, the resonance characteristic of the whole structure is changed, and the purpose of tuning vibration reduction is achieved.
The following detailed description of the present invention will be made with reference to the accompanying drawings.
Example 1
As shown in figure 1, the integral appearance structure of the tuned magnetic liquid rolling ball damper comprises a cylindrical container 1 with a hemispherical groove therein, a cylindrical solenoid coil 2, a horizontal base 3 and a hollow rolling ball 4; and tightly pressing and winding the copper core enameled wire on the wall surface of the shell of the cylindrical container main body to manufacture the solenoid coil 2.
As shown in figure 2, the integral section structure of the tuning type magnetic liquid rolling ball damper is characterized in that a coal oil-based magnetic liquid 5 is filled in a hollow rolling ball 3, the volume of the injected magnetic liquid is 1/2 of the internal volume of a ball shell, and the hollow rolling ball can drive the magnetic liquid to roll along the wall surface of a groove. The magnetic liquid 5 is kerosene-based Fe3O4Magnetic liquid with density of about 1.36g/cm3The viscosity is 6.63mPa & s, the saturation magnetization is 513.7Gs, wherein the ferroferric oxide is nano-particles, and the diameter range is 2-20 nm.
As shown in figure 3, the sectional structure of the whole shell of the tuning type magnetic liquid rolling ball damper of the invention has the advantages that the diameter of a cylindrical container main body shell 1-2 is 110cm, the radius of an internal hemispherical groove 1-3 is 50cm, the top part is the upper edge 1-1 of the shell, the diameter of the shell is 10cm, the thickness of the shell is 5cm, the bottom part is a damper base 3-2, the diameter of the damper base is 150cm, the thickness of the damper base is 10cm, three threaded holes with the diameter of about 8.5mm are uniformly distributed on the circumference of the base with the radius of 130cm, and the damper is used for being fixed on a vibration structure.
As shown in figure 4, the integral structure of the cylindrical solenoid coil of the tuned magnetic liquid ball damper of the invention is that copper core enameled wires with the wire diameter of about 1.1mm are tightly pressed outside the cylindrical container body part 1-2 to form the cylindrical solenoid coil in the figure. The cylindrical solenoid coil is a solenoid with 5 layers of each layer of 80 turns and 400 total turns, wherein the 5 layers of each layer. According to international regulations, a copper core wire with 1 square millimeter allows a long-term load current to be 6A-8A, a safety margin is reserved, and a rated working current does not exceed 5A.
As shown in figure 5, the hollow rolling ball 2 of the tuning type magnetic liquid rolling ball damper has an integral structure, is a rollable thin-wall ball shell made of ABS resin material, and has the wall thickness of 10mm and the diameter of 12 cm; the top of the shell is provided with a cylindrical threaded hole 4-2 with the diameter of about 8.5mm for containing kerosene-based magnetic liquid 5, and an ABS resin material threaded plug 4-3 with the corresponding type is assembled to ensure screwing and sealing, so that a closed spherical shell is formed and can roll in any direction on the hemispherical groove surface.
As shown in FIG. 6, the magnetic flux density variation curve along the sectional line of the hemispherical groove surface in the tuned magnetic liquid rolling ball damper is shown as the magnetic flux density variation curve along the sectional line of the groove when 4A direct current is introduced into the solenoid coil, the magnetic flux density variation is about 175 Gs-260 Gs, the magnetic flux density required by the viscosity variation of the kerosene-based magnetic liquid 5 is 40 Gs-300 Gs, and the magnetic field requirement required by the viscosity variation of the kerosene-based magnetic liquid is met, so that the viscosity of the kerosene-based magnetic liquid can be effectively adjusted by changing the magnitude of the current introduced into the solenoid coil, the resonance characteristic of the whole structure is changed, and tuned vibration reduction is realized.
The invention has the advantages that: firstly, compared with the traditional tuned liquid damper, the rolling ball drives the magnetic liquid to roll together, so that the magnetic liquid is in a turbulent flow state quickly, the quick dissipation of structural vibration energy is increased, and the using amount of the liquid, particularly the magnetic liquid, can be greatly reduced; meanwhile, the small ball rolling friction also increases the dissipation of structural vibration energy; compared with a tuned rolling ball damper and a tuned mass damper, the controllability is increased, and the vibration reduction frequency of the damper can be changed by an external magnetic field; compared with most tuned dampers, the damper has wider vibration reduction frequency band, the vibration reduction frequency band is increased by 0.14Hz, and the vibration reduction frequency band is increased by 56 percent in the original vibration reduction frequency band, which is a great improvement; meanwhile, in the test of the wind power tower experimental model, when the mass of the damper is 1.5% -2.5% of the first-order modal mass of the vibration structure experimental model, the standard deviation of the tower top displacement can be reduced by 20% -42%, the vibration response and fatigue damage of the wind power tower structure can be effectively reduced, and the service life of the wind power tower is prolonged.
The damper is a tuned damper, and the shaking frequency of the damper is adjusted according to the natural frequencies of different buildings; adjusting the shaking frequency of the damper: and determining the radius of the container, the radius of the small ball and the mass of the magnetic liquid according to the natural frequency of the vibration structure and the modal mass ratio of the damper to the vibration structure, wherein when the structure receives external complex disturbance, the natural frequency can be deviated, and at the moment, the external magnetic field is changed. For the same type of high-rise structure, such as wind power towers, the difference of the first-order natural frequencies of different wind power towers is small, so that the mass production can be realized after the geometric dimension of the damper is determined, and the damper can be suitable for the same type of high-rise structure only by adjusting an external magnetic field.
Through analysis and calculation, the radius of the rolling ball does not exceed 1/8 of the radius of the groove, the movement state of the rolling ball is subjected to force analysis and calculation under the limit condition (the radius of the rolling ball is 1/8 of the radius of the groove), and when the external given acceleration is 32m/s2When the ball rises to the highest, the distance between the ball and the edge of the groove is 1/10 of the radius of the ball; when the wind power tower is subjected to the acceleration of 20m/s2The alarm state can be triggered when the wind power tower is disturbed, so that the small balls cannot fall within the range of the external disturbance which can be borne by the wind power tower.
Aiming at different sizes and heights of attachments, the size difference between the radius of the groove of the damper and the radius of the rolling ball can be analyzed and calculated according to the first-order natural vibration frequency of the attachments, then the geometric size of the damper and the volume of magnetic liquid can be determined according to the modal mass ratio of the damper and the attachments, when the attachments receive different external disturbances, the size of current introduced into a solenoid coil is adjusted according to the vibration frequency deviation, the natural frequency of the damper is changed, the resonance characteristic is adjusted, and the purpose of tuning vibration reduction is achieved.
The wind power tower is a wind power generation tower, and the damper is arranged at the top end inside the tower barrel of the wind power tower and is located in a semi-closed space, so that foreign matters and even rainwater cannot fall into the open design. The damper is also popularized to other high-rise structures, and the damper is generally arranged at the top end of the interior of the structure, so that foreign matters cannot fall into the damper.
The application method of the tuned magnetic liquid ball damper is characterized by comprising the following steps:
firstly, according to the vibration intensity and frequency of the structure, coal oil-based magnetic liquid with a certain volume is filled in the small ball, and the screw plug is screwed in for sealing, so that the magnetic liquid cannot be leaked when the small ball rolls.
And secondly, manufacturing a cylindrical solenoid coil, and tightly winding the copper core enameled wire to a position which is 0.5-1.5 cm away from the outer edge of the upper part of the shell along the outer part of the cylindrical container body from bottom to top in a single layer manner to wind 4-7 layers in total.
And thirdly, placing the assembled damper on the horizontal plane of the vibration structure, fixing the damper on the vibration structure through a threaded hole in the horizontal base, and placing the ball with the assembled magnetic liquid at the bottom of the hemispherical groove.
And fourthly, connecting two joint ends of a solenoid coil at the bottom of the device into the output end of a direct current source, turning on the direct current source, slowly increasing the current, controlling the adjustable current input by the current source introduced into the solenoid coil so as to control the shaking frequency of the damper, changing the structural resonance characteristic and realizing tuned vibration reduction.
Through the above embodiments, we can summarize the following features of the present invention:
1. the electrified solenoid coil is wound by adopting a cylindrical design structure, so that the uniformity of the magnetic field distribution in the inner space of the cylindrical container can be effectively improved, and the input current signal and the viscosity of the magnetic liquid have better linearity.
2. Compared with the traditional tuned liquid damper which changes the natural oscillation frequency by changing the liquid depth or the geometric dimension of a container, the invention improves the control method, and controls the viscosity of the magnetic liquid by adjusting the direct current of the input solenoid coil, thereby controlling the natural frequency of the oscillation liquid and achieving the purpose of tuning vibration reduction.
3. Compared with the traditional tuned mass damper for changing the natural frequency by changing the mass of the mass block or the elastic coefficient of the spring, the invention adopts the container with the hemispherical groove surface, can change the natural frequency of the damper by designing the geometric dimensions of the small ball and the hemispherical groove, and can change the natural frequency of the damper by controlling the natural shaking frequency of the magnetic liquid in the spherical shell by taking the kerosene-based magnetic liquid as one part of the mass block, thereby realizing the double tuning capability.
4. The kerosene-based magnetic liquid is filled into the hollow rolling ball and sealed by the threaded plug, so that the volatilization of the magnetic liquid in a working environment can be effectively reduced, and the stability of the magnetic liquid and the reliability of the damper are improved.
5. The rolling ball can roll along any direction on the hemispherical groove surface, so that the structure can be reduced from shaking in any direction in the horizontal plane, and the multi-directional vibration reduction function is realized.
6. The bottom of the damper shell adopts a structural design with three threaded hole discs, and is fixedly connected with the vibration structure through bolts, so that the damper has better stability in work.
The invention is applicable to the prior art.
Claims (4)
1. A tuning type magnetic liquid rolling ball damper is characterized in that the damper comprises a cylindrical container with a hemispherical groove inside, a cylindrical solenoid coil, a horizontal base, a hollow rolling ball and kerosene-based magnetic liquid; the cylindrical solenoid coil is uniformly wound on the wall surface of the shell of the cylindrical container main body, the cylindrical container is positioned on the horizontal base, and the coal oil-based magnetic liquid is arranged in the hollow rolling ball; the hollow rolling ball is arranged in a hemispherical groove in the cylindrical container;
the upper part of the cylindrical container is an open type hemispherical groove, the top of the groove is a convex shell upper edge, and the bottom of the cylindrical container is a convex horizontal base;
the hollow rolling ball is a hollow ball body; the top of the shell is provided with a screw hole provided with a threaded plug;
the radius of the hollow rolling ball is 1/12-1/8 of the radius of the groove;
the cylindrical solenoid coil is a copper core enameled wire, 4-7 layers of solenoid coils are wound in total, and the rated current is 5A;
the kerosene-based magnetic liquid is kerosene-based Fe3O4Magnetic liquid with density of 1.36g/cm3(ii) a Ferroferric oxide is nano-particles, and the diameter range is 2-20 nm; the volume of the kerosene-based magnetic liquid is 1/4-3/4 of the internal volume of the spherical shell.
2. The tuned magnetic liquid ball damper according to claim 1, wherein said horizontal base has fixing screw holes uniformly distributed along the circumference.
3. The tuned magnetic liquid ball damper according to claim 1, wherein said cylindrical body housing has a diameter in the range of 0.65m to 1.45m and an internal hemispherical recess radius in the range of 0.3m to 0.7 m.
4. The tuned magnetic liquid ball damper according to claim 1, wherein the shell thickness of said hollow ball is 8-12 mm; the material is resin material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911344604.7A CN110965837A (en) | 2019-12-24 | 2019-12-24 | Tuning type magnetic liquid rolling ball damper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911344604.7A CN110965837A (en) | 2019-12-24 | 2019-12-24 | Tuning type magnetic liquid rolling ball damper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110965837A true CN110965837A (en) | 2020-04-07 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117345555A (en) * | 2023-11-09 | 2024-01-05 | 哈尔滨工程大学 | Intelligent damping vibration attenuation system for offshore wind power |
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