A bidirectional passive / active tuned mass damper with ball bearings

Abstract

This invention belongs to the field of marine engineering and structural vibration control technology, and discloses a ball-bearing supported bidirectional active-passive tuned mass damper, which is composed of two arc-shaped tuned mass dampers with perpendicular motion directions. The inertial mass is supported on an arc-shaped base by a ball bearing assembly, cleverly converting sliding friction into low-resistance rolling friction, making the damper more sensitive to start, while maintaining a compact structure. In terms of passive control, the device dissipates energy through electromagnetic damping generated by the relative motion between the magnet assembly and the conductor plate. The integrated active control system, composed of a drive coil and a magnet assembly, can apply additional active control force to the TMD, thereby upgrading the traditional passive TMD to a higher-performance active-passive hybrid system, enhancing its adaptability and robustness to complex loads. In addition, the device adopts a non-contact electromagnetic guidance design, utilizing a figure-eight coil assembly in conjunction with a lateral magnet assembly to eliminate the friction of traditional mechanical guidance mechanisms.

Description

Technical Field

[0001] This invention belongs to the field of marine engineering and structural vibration control technology, and relates to a ball-bearing bidirectional active and passive tuned mass damper. Background Technology

[0002] The rapid advancement of wind power technology has made it possible to utilize wind energy sustainably and efficiently. However, with the continuous increase in single-unit capacity and tower height, the structural safety and fatigue life of wind turbines under the combined effects of complex environmental loads are becoming increasingly prominent issues.

[0003] Vibration control systems can effectively suppress structural vibrations and reduce the probability of structural damage. Tuned mass dampers (TMDs) are relatively inexpensive and offer good control, making them widely used in vibration control of highly flexible structures. They mainly consist of a stiffness system, a damping system, an inertial mass, a guiding system, and other auxiliary components.

[0004] Depending on the installation method, TMDs can be broadly classified into supported TMDs and suspended TMDs. Suspended TMDs are simple in construction and can simultaneously control vibrations along two principal axes of the structure. Their period is positively correlated with the length of the suspension cable; therefore, in highly flexible structures, the use of suspended TMDs often results in excessively long pendulums, occupying a large amount of internal structural space. Second, some pendulum TMDs, under bidirectional motion coupling, cannot strictly move along the principal axes of the structure, but instead rotate around their equilibrium position. This causes the TMD parameters to deviate from their optimal state, failing to achieve the best vibration reduction performance. Third, suspended TMDs involve various friction factors, such as the connection friction between the suspension cable and the structure, the friction between the suspension cable and the inertial mass, and the friction between the damping devices, which not only affect the TMD's sensitivity but also its service life. Fourth, passive TMDs generally only have a good vibration reduction effect on structural vibrations of a specific frequency. When the vibration frequency of the controlled structure deviates from the specific frequency, the vibration reduction effect of passive TMDs is poor, or even has the opposite effect on the structure.

[0005] The stiffness and damping of a supported TMD are typically provided by springs and liquid dampers, respectively. A guide rod acts as a guiding device to ensure the inertial mass moves along the designed direction. Besides having relatively high friction and being insensitive to minor vibrations, this type of TMD also suffers from problems such as liquid leakage causing environmental pollution and only providing vibration reduction for a single frequency. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a ball-bearing bidirectional active and passive tuned mass damper, which solves the problems of insensitivity to minute vibrations, single control frequency, and poor robustness.

[0007] The technical solution of the present invention: A ball-supported bidirectional active-passive tuned mass damper includes: The mass system consists of inertial mass one and inertial mass two, which is composed of inertial mass one and the arc-shaped base one. The support system includes a ball bearing assembly disposed between the inertial mass and the curved base, which converts sliding friction into rolling friction; The damping system consists of a magnet assembly fixed to the lower surface of the inertial mass and a conductor plate fixed to the upper surface of the arc-shaped base. Electromagnetic damping is generated through the relative motion of the two. The electromagnetic drive system consists of a magnet assembly fixed to the lower surface of the inertial mass and a drive coil assembly fixed to the upper surface of the arc-shaped base, and is used to provide active control force. The electromagnetic guidance system consists of a magnet assembly fixed to the side of the inertial mass and an "8"-shaped coil assembly fixed to the inside of the back plate assembly, achieving frictionless guidance; the back plate assembly is fixed on both sides of the arc-shaped base perpendicular to the generatrix of the cylindrical surface.

[0008] The inertial mass 1 is supported on the arc-shaped base 1 by the first ball bearing assembly. The contact surfaces of the two are a first arc-shaped structure and a second arc-shaped structure with the same curvature, which together constitute an arc-shaped TMD1 with a first vibration period and direction. The inertial mass 1 and the arc-shaped base 1 are integrated and supported on the arc-shaped base 2 by the second ball bearing assembly. The contact surfaces of the bottom of the arc-shaped base 1 and the top of the arc-shaped base 2 are a third arc-shaped structure and a fourth arc-shaped structure with the same curvature, which together constitute an arc-shaped TMD2 with a second vibration period and direction. The swing directions of the arc-shaped TMD1 and the arc-shaped TMD2 are perpendicular to each other.

[0009] The generatrix of the cylindrical surface formed by the first and second arc-shaped structures is perpendicular to the generatrix of the cylindrical surface formed by the third and fourth arc-shaped structures.

[0010] The ball bearing assembly in the support system is placed in an annular track on the upper surface of the arc-shaped base; a protective cover is provided above the annular track to prevent the ball bearings from escaping.

[0011] The cross-section of the annular track is arc-shaped, with the curvature of its major axis matching that of the arc-shaped base, and its minor axis being a straight line.

[0012] In the damping system and electromagnetic drive system, the magnets fixed to the lower surface of the inertial mass are arranged in a Halbach array.

[0013] In the electromagnetic guidance system, the magnet groups fixed on both sides of the inertial mass are arranged along the direction of motion and are arranged in a Halbach array.

[0014] Each figure-eight coil in the electromagnetic guidance system is formed by twisting a rectangular electromagnetic coil, and two figure-eight coils arranged opposite each other are connected by a wire.

[0015] The conductor plate in the damping system is made of copper, and its curvature is consistent with the bottom arc structure of the corresponding inertial mass.

[0016] The drive coil group in the electromagnetic drive system is arranged on the upper surface of the conductor plate. The number of coil groups, the number of turns in each coil group, and the coil arrangement can be designed according to the required driving force.

[0017] The beneficial effects of this invention are: (1) The inertial mass is connected to the structure through the arc-shaped base, avoiding the use of slings, which makes the structure simple and saves installation space; (2) TMD1 and TMD2 move independently and in orthogonal directions, which avoids the problem of rotation of the suspended TMD under multi-directional load, and has a better vibration reduction effect; (3) The periods of TMD1 and TMD2 can be designed to have different values, thus enabling control of two vibration modes; (4) The inertial mass is supported by multiple sets of ball bearings on an arc-shaped base. The multiple balls arranged in a ring can circulate and roll in the ring track, so there is only rolling friction between the balls and the mass block, making the TMD start more sensitive.

[0018] (5) The magnets on the lower surface of the inertial mass are arranged in a Halbach array. Compared with the ordinary N-S interleaved arrangement, the Halbach array increases the magnetic induction intensity by about 20%.

[0019] (6) The electromagnetic guidance system, consisting of magnets on both sides of the inertial mass and a figure-eight coil, can constrain the direction of motion of the inertial mass without contacting it. This eliminates the frictional force in the mechanical guidance device of traditional TMD.

[0020] (7) The electromagnetic drive system can provide driving force for the inertial mass, thereby controlling the motion characteristics of the inertial mass, transforming the passive TMD into an active-passive TMD, so that the TMD has a good vibration reduction effect on multiple frequencies of the structure. Attached Figure Description

[0021] Figure 1 This is a perspective view of a ball-supported bidirectional active and passive tuned mass damper according to the present invention. Figure 2 This is an exploded view of a ball-supported bidirectional active-passive tuned mass damper according to the present invention. Figure 3The images show a three-dimensional and a perspective view of the inertial mass of a ball-supported bidirectional active and passive tuned mass damper according to the present invention; wherein, (a) is a front view, (b) is a left view, (c) is a top view, and (d) is a perspective view. Figure 4 The figures are three-dimensional and perspective views of the arc-shaped base and the first back plate assembly of a ball-bearing bidirectional active and passive tuned mass damper of the present invention; wherein, (a) is the front view, (b) is the left view, (c) is the top view, and (d) is the perspective view. Figure 5 The present invention provides a three-dimensional and a perspective view of the arc-shaped base and the second backplate assembly of a ball-supported bidirectional active and passive tuned mass damper. Figure 6 This is a schematic diagram of the figure-eight coil group of a ball-supported bidirectional active and passive tuned mass damper according to the present invention.

[0022] In the diagram: 1. Inertial Mass I; 2. First Magnet Group; 3. Arc-shaped Base I; 4. Arc-shaped Base II; 5. First Conductor Plate; 6. Second Conductor Plate; 7. First Figure-Eight Coil Group; 8. Third Magnet Group; 9. First Backplate Group; 10. Second Backplate Group; 11. Ball Bearing Group; 12. Protective Cover; 13. Fourth Magnet Group; 14. Second Figure-Eight Coil Group; 15. Second Magnet Group; 16. First Drive Coil Group; 17. Second Drive Coil Group; 101. Rectangular Slot I; 102. Rectangular Slot II; 301. Arc-shaped Slot I; 302. Circular Track I; 303. Rectangular Slot III; 304. Rectangular Slot IV; 401. Arc-shaped Slot II; 402. Circular Track II. Detailed Implementation

[0023] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0024] A ball-bearing-supported bidirectional active and passive tuned mass damper includes an inertial mass 1, an arc-shaped base 1, a first magnet group 2, an arc-shaped base 2 3, an arc-shaped base 2 4, a first conductor plate 5, a second conductor plate 6, a first figure-eight coil group 7, a third magnet group 8, a first back plate group 9, a second back plate group 10, a ball group 11, a protective cover 12, a fourth magnet group 13, a second figure-eight coil group 14, a second magnet group 15, a first drive coil group 16, and a second drive coil group 17.

[0025] Combination Figure 1 , Figure 2 As shown, inertial mass 1 and arc-shaped base 3 together constitute arc-shaped TMD1. Inertial mass 1 and arc-shaped base 3 together constitute inertial mass 2, and inertial mass 2 and arc-shaped base 4 together constitute arc-shaped TMD2. The motion directions of arc-shaped TMD1 and arc-shaped TMD2 are orthogonal.

[0026] The lower surface of inertial mass 1 and the upper surface of the arc-shaped base 3 are provided with cylindrical surfaces of the same curvature. A rectangular groove 102 of a certain size is provided in the center of the lower surface of inertial mass 1, and a first magnet group 2 arranged in a Halbach array is installed inside it. A third magnet group 8 is symmetrically arranged on both sides of inertial mass 1. The area S of the magnet group 2 located on the lower surface of the mass block can be calculated by the following formula: (1) In the formula, Let be the area of ​​the magnet assembly located on the lower surface of inertial mass -1. These are the required damping coefficient, conductor plate conductivity, adjustment coefficient determined by experiment, conductor plate thickness, and magnetic induction intensity in the normal direction of the arc surface of the conductor plate.

[0027] The upper surface of the arc-shaped base 3 has an arc-shaped groove 301 of a certain size along the direction of motion of the inertial mass 1. Symmetrically arranged annular tracks 302 are provided on both sides of the arc-shaped groove 301. A first backplate group 9, with a length greater than that of the inertial mass 3, is symmetrically arranged outside the annular tracks 302. A first conductor plate 5 is embedded in the arc-shaped groove 301, and its surface curvature is the same as that of the arc-shaped track 3. A certain number of steel ball bearing groups 11 are arranged inside the annular tracks 302. A certain number of first figure-eight coil groups 7 are provided inside the first backplate group 9.

[0028] The ball bearing assembly 11 must have sufficient load-bearing capacity to support inertial mass, and its material should be steel with high hardness and wear resistance after undergoing a certain heat treatment process. Its quantity is designed according to actual needs, and the load-bearing capacity P of a single ball bearing can be calculated using the following formula: (2) In the formula, For the load-bearing capacity of ball bearing assembly 11, These are the elastic modulus, radius, and allowable contact stress of the ball assembly 11, respectively.

[0029] The major axis of the circular track 302 is parallel to the direction of motion of the inertial mass 3, and the minor axis is perpendicular to the direction of motion of the inertial mass 3. The major axis is a curve with the same curvature as the arc-shaped base 3, and the minor axis is a straight line at a certain angle to the generatrix of the arc-shaped base 3. The cross-section of the circular track 302 is semi-circular, and one side is covered by a protective cover 12.

[0030] To ensure that the inertial mass 3 moves along the set direction without increasing the system's friction, an electromagnetic guidance system consisting of a third magnet group 8 and a first figure-eight coil group 7 is arranged on both sides of the inertial mass 3. In practice, the magnetic field lines of the third magnet group 8 pass through the first figure-eight coil group 7, which consists of two figure-eight electromagnetic coils connected in series. When the inertial mass 3 deviates from the set direction, an induced current is generated in the electromagnetic coil group, which in turn generates an electromagnetic force opposite to the direction of deviation, forcing the inertial mass 3 back to the set direction of motion.

[0031] The lower surface of the arc-shaped base 3 has a cylindrical surface with the same curvature as the upper surface of the arc-shaped base 4. A rectangular groove 303 of a specific size is located in the center of the lower surface of the arc-shaped base 3, inside which a second magnet group arranged in a Halbach array is installed. A fourth magnet group 13 is symmetrically designed on both sides of the arc-shaped base 3. The radius of curvature R can be calculated using the following formula; (3) In the formula, To account for the equivalent radius of curvature at the centroid location, These are the oscillation period of the inertial mass and the acceleration due to gravity, respectively.

[0032] The upper surface of the arc-shaped base 4 has an arc-shaped groove 401 of a certain size along the direction of movement of the arc-shaped base 3. Symmetrically arranged annular tracks 402 are provided on both sides of the arc-shaped groove 401. A second backplate assembly 10 is symmetrically arranged on the outer side of the annular tracks 402. A second conductor plate 6 is embedded in the arc-shaped groove 401, and its surface curvature is the same as that of the arc-shaped track 4. A certain number of steel balls are arranged inside the annular tracks 402. A second figure-eight coil assembly 14 is provided inside the second backplate assembly 10.

[0033] The figure-eight coil is made of copper wire. The first conductor plate 5 and the second conductor plate 6 are both made of copper; the magnets are both neodymium iron boron permanent magnets.

[0034] The first electromagnetic drive coil group 16 and the first electromagnetic drive coil group 17 are located on the upper surfaces of the arc-shaped base 3 and the arc-shaped base 4, respectively. This allows the passive TMD to be converted into a hybrid active-passive TMD, resulting in better vibration reduction.

[0035] The beneficial effects of the embodiments of the present invention are at least as follows: First, the inertial mass is connected to the structure through an arc-shaped base, avoiding the use of slings, which simplifies the structure and saves installation space; Secondly, the motion of TMD1 and TMD2 is independent and their directions of motion are orthogonal, which avoids the problem of rotation of the suspended TMD under multi-directional loads and has a better vibration reduction effect. Third, the periods of TMD1 and TMD2 can be designed to have different values, thus enabling control of two vibration modes; Fourth, the inertial mass is supported by multiple sets of ball bearings on an arc-shaped base. The multiple balls arranged in a ring can circulate within the ring track, so there is only rolling friction between the balls and the mass block, making the TMD start-up more sensitive.

[0036] Fifth, the first magnet group 1 and the second magnet group 15 on the lower surface of the inertial mass are arranged in a Halbach array pattern. Compared with the ordinary N / S alternating arrangement, the Halbach array pattern increases the magnetic induction intensity by about 20%.

[0037] Sixth, the electromagnetic guidance system, consisting of the third magnet group 8 and the fourth magnet group 13 located on both sides of the inertial mass-1 and the arc-shaped base-3, and the first figure-eight coil group 7 and the second figure-eight coil group 14 respectively, can constrain the direction of motion of the inertial mass without contacting it. This eliminates the frictional force in the guidance device of traditional TMD.

[0038] Seventh, the electromagnetic drive system can provide driving force for the inertial mass, thereby controlling the motion characteristics of the inertial mass, transforming the passive TMD into an active-passive TMD, so that the TMD has a good vibration reduction effect on multiple frequencies of the structure.

[0039] Ultimately, this invention provides a controlled structure with an active and passive tuned mass damper that exhibits good vibration reduction for horizontal vibrations in any direction and for multi-order arrays, is sensitive to minute vibrations, has a quick start-up, and is durable.

Claims

1. A ball-bearing supported bidirectional active-passive tuned mass damper, characterized in that, This bidirectional active-passive tuned mass damper includes: The mass system consists of inertial mass one and inertial mass two, which is composed of inertial mass one and the arc-shaped base one. The support system includes a ball bearing assembly disposed between the inertial mass and the curved base, which converts sliding friction into rolling friction; The damping system consists of a magnet assembly fixed to the lower surface of the inertial mass and a conductor plate fixed to the upper surface of the arc-shaped base. Electromagnetic damping is generated through the relative motion of the two. The electromagnetic drive system consists of a magnet assembly fixed to the lower surface of the inertial mass and a drive coil assembly fixed to the upper surface of the arc-shaped base, and is used to provide active control force. The electromagnetic guidance system consists of a magnet assembly fixed to the side of the inertial mass and an "8"-shaped coil assembly fixed to the inside of the back plate assembly, achieving frictionless guidance; the back plate assembly is fixed on both sides of the arc-shaped base perpendicular to the generatrix of the cylindrical surface.

2. The bidirectional active-passive tuned mass damper according to claim 1, characterized in that, The inertial mass 1 is supported on the arc-shaped base 1 by the first ball bearing assembly. The contact surfaces of the two are a first arc-shaped structure and a second arc-shaped structure with the same curvature, which together constitute an arc-shaped TMD1 with a first vibration period and direction. The inertial mass 1 and the arc-shaped base 1 are integrated and supported on the arc-shaped base 2 by the second ball bearing assembly. The contact surfaces of the bottom of the arc-shaped base 1 and the top of the arc-shaped base 2 are a third arc-shaped structure and a fourth arc-shaped structure with the same curvature, which together constitute an arc-shaped TMD2 with a second vibration period and direction. The swing directions of the arc-shaped TMD1 and the arc-shaped TMD2 are perpendicular to each other.

3. The bidirectional active-passive tuned mass damper according to claim 2, characterized in that, The generatrix of the cylindrical surface formed by the first and second arc-shaped structures is perpendicular to the generatrix of the cylindrical surface formed by the third and fourth arc-shaped structures.

4. The bidirectional active-passive tuned mass damper according to claim 3, characterized in that, The ball bearing assembly in the support system is placed in an annular track on the upper surface of the arc-shaped base; a protective cover is provided above the annular track to prevent the ball bearings from escaping.

5. The bidirectional active-passive tuned mass damper according to claim 4, characterized in that, The cross-section of the annular track is arc-shaped, with the curvature of its major axis matching that of the arc-shaped base, and its minor axis being a straight line.

6. The bidirectional active-passive tuned mass damper according to claim 1, characterized in that, In the damping system and electromagnetic drive system, the magnets fixed to the lower surface of the inertial mass are arranged in a Halbach array.

7. The bidirectional active-passive tuned mass damper according to claim 1, characterized in that, In the electromagnetic guidance system, the magnet groups fixed on both sides of the inertial mass are arranged along the direction of motion and are arranged in a Halbach array.

8. The bidirectional active-passive tuned mass damper according to claim 1, characterized in that, Each figure-eight coil in the electromagnetic guidance system is formed by twisting a rectangular electromagnetic coil, and two figure-eight coils arranged opposite each other are connected by a wire.

9. The bidirectional active-passive tuned mass damper according to claim 1, characterized in that, The conductor plate in the damping system is made of copper, and its curvature is consistent with the bottom arc structure of the corresponding inertial mass.

10. The bidirectional active-passive tuned mass damper according to claim 1, characterized in that, The drive coil group in the electromagnetic drive system is arranged on the upper surface of the conductor plate. The number of coil groups, the number of turns in each coil group, and the coil arrangement are designed according to the required driving force.

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