Inerter-adjustable nonlinear vibration absorption device
By using an adjustable inertial capacitance nonlinear vibration absorption device, which utilizes a ball screw inertial container and an obliquely arranged linear damper, the problems of narrow bandwidth and large added mass of linear and traditional nonlinear vibration absorbers are solved, achieving lightweight and efficient vibration reduction of the vibration absorber.
Patent Information
- Application Number
- CN202422644569.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-10-31
AI Technical Summary
Existing linear vibration dampers and traditional nonlinear vibration absorbers suffer from narrow operating frequency bands and large added mass.
An adjustable inertial capacitance nonlinear vibration absorption device is adopted, which uses a ball screw inertial capacitance to replace the additional slider, and combines a sliding slider and an obliquely arranged linear damper to achieve adjustment of the inertial capacitance coefficient and enhancement of the nonlinear damping force.
It effectively reduces the added mass of the vibration absorber, increases the operating bandwidth, and enhances the vibration reduction effect at high speeds.
Smart Images
Figure CN223524297U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the technical field of vibration damper structure design, concretely relates to a kind of inertial capacity adjustable nonlinear vibration absorber. BACKGROUND
[0002] Vibration phenomenon exists widely, and it has both advantages and disadvantages. In order to minimize the disadvantages brought by vibration, many mechanical devices adopt linear spring + damper tuned mass damper, and good vibration reduction effect is achieved, but it also has some shortcomings, such as bidirectional transmission of vibration energy, narrow working frequency band, and large additional mass.
[0003] Compared with linear vibration absorber, nonlinear vibration absorber (also known as nonlinear energy sink) has wider working frequency band and one-way transmission of vibration energy, and thus it has gradually become a focus of attention in engineering and academic circles. From the structure, nonlinear vibration absorber mainly consists of nonlinear spring, damper and additional slider. Nonlinear vibration absorber has its unique advantages compared with linear vibration absorber, but both linear and nonlinear vibration absorbers have the problem of large additional mass, which is usually between 5% and 10% of the mass of the main structure.
[0004] However, the British scholar Smith proposed the concept of inertial capacity, which is a new type of structure control element with acceleration-dependent points at both ends. The inertial capacity coefficient generated by it can be much larger than its own physical mass or moment of inertia, greatly reducing the problem of large additional mass, and it is also relatively easy to implement in structure. The emergence of inertial capacity effectively improves the structure and overall mass of the vibration absorber. UTILITY MODEL CONTENT
[0005] The utility model aims to provide a kind of inertial capacity adjustable nonlinear vibration absorber to solve the problems of narrow working frequency band and large additional mass in linear vibration damper technology, or the problem of large additional mass in traditional nonlinear vibration absorber.
[0006] In order to achieve the above-mentioned purpose, the present application mainly provides the following technical scheme: a kind of inertial capacity adjustable nonlinear vibration absorber, including upper outer shell, lower outer shell, ball screw inertial container, linear spring damper, connecting plate and connecting rod, the upper outer shell is sleeved on the outside of lower outer shell, and the top of upper outer shell is symmetrically installed with hinge, the hinge is hingedly connected with the upper end of linear spring damper, the lower end of linear spring damper is connected with connecting plate through hinge, the connecting plate is connected with the inertial container shell of ball screw inertial container through connecting rod, the inertial container shell is provided with nut assembly combination body, the nut assembly combination body is movably connected with screw rod, the lower end of screw rod is fixedly connected at the bottom of lower outer shell, and the upper end of screw rod is fixedly connected at the top of lower outer shell, when connecting rod drives inertial container shell to move up and down, nut assembly combination body will reciprocatingly rotate around screw rod.
[0007] In some embodiments, the ball screw inertial container further comprises a first tapered roller bearing and a second tapered roller bearing located at the upper and lower ends of the inertial container shell and sleeved on the nut assembly combination, when the inertial container shell moves up and down, the corresponding first tapered roller bearing or second tapered roller bearing is pushed to move synchronously, so as to drive the nut assembly combination to rotate reciprocatingly around the screw rod.
[0008] In some embodiments, the nut assembly combination comprises a nut, and a flange sleeve bolted with the nut, the screw rod is movably connected in the nut and the flange sleeve, a positioning shoulder is arranged on the flange sleeve, and the first tapered roller bearing is arranged between the upper end of the inertial container shell and the positioning shoulder.
[0009] In some embodiments, the nut assembly combination further comprises a slider and a tension spring, the slider is slidingly arranged in a dovetail groove on the flange sleeve, and the tension spring is connected at one end to the flange sleeve and at the other end to the slider.
[0010] In some embodiments, a lower shell cover is further included, and the lower shell cover is provided with an outer edge with an inner diameter and an outer diameter consistent with those of the upper outer shell.
[0011] In some embodiments, an upper lifting lug is arranged on the top outer side of the upper outer shell, and a lower lifting lug is arranged on the bottom outer side of the lower outer shell.
[0012] In some embodiments, the lower end of the screw rod is fixedly connected to the bottom of the lower outer shell through a connecting sleeve, and the upper end of the screw rod is fixedly connected to the top of the lower outer shell through a star-shaped piece, and the center line of the star-shaped piece is coaxial with the center line of the connecting sleeve, so as to ensure that the nut does not jam during the up-down movement.
[0013] In some embodiments, the inertial container shell is an inertial container upper shell cover and an inertial container lower shell cover arranged at the upper and lower ends of the inertial container side wall, and the inertial container upper shell cover and the inertial container lower shell cover are provided with coaxial center holes for the upper and lower ends of the screw rod to extend out.
[0014] Compared with the prior art, the beneficial effects of the present application mainly include:
[0015] (1) The ball screw inertial container of the present application replaces the additional slider in the traditional nonlinear vibration absorber, and the inertia mass during the rotation of the nut is several times larger than the mass itself, which can be used for further lightweight of the nonlinear vibration absorber structure mass.
[0016] (2) In order to further improve the vibration absorber at higher speed, the utility model improves the inertia coefficient of the ball screw automatically, and additionally increases the slidable slider on the nut, the slider is connected with the nut by linear spring, in the rotation process of the nut, with the increase of the rotation speed of the nut, under the action of centrifugal force, the slider automatically moves away from the rotation center of the nut, the moment of inertia of the nut is increased, and the inertial coefficient of the ball screw container is also increased.
[0017] (3) The linear damper is arranged symmetrically, and the nonlinear damping energy consumption behavior is realized, according to the mathematical expression of nonlinear damping force, the energy consumption capacity of the nonlinear damper at higher speed can be effectively improved.
[0018] (4) The lower shell cover is provided with a certain outer edge, the height of the outer edge is h, the inner and outer diameters of the outer edge are same with the inner and outer diameters of the upper shell, and the outer edge provides the limit for the upper shell, so as to protect the linear spring damper and the ball screw inertial container in the interior from exceeding the maximum stroke. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is the overall structure diagram of the utility model;
[0020] Figure 2 It is the ball screw inertial unit structure diagram of the utility model with adjustable inertial coefficient;
[0021] Figure 3 It is the internal structure diagram of the ball screw inertial unit with adjustable inertial coefficient of the utility model;
[0022] Figure 4 It is the nonlinear spring and nonlinear damping principle diagram of the utility model;
[0023] Figure 5 It is the ball screw inertial container principle diagram of the utility model.
[0024] In the drawings: 1 upper lug, 2 hinge, 3 linear damper, 4 connecting plate, 5 upper outer shell, 6 star-shaped part, 7 lower outer shell, 8 lower lug, 9 connecting rod, 10 screw rod, 11 inertial container upper shell cover, 12 inertial container lower shell cover, 13 inertial container side wall, 14 first tapered roller bearing, 15 second tapered roller bearing, 16 connecting sleeve, 17 lower shell cover, 18 nut, 19 flange shaft sleeve, 20 slider, 21 eye, 22 tension spring, 23 positioning shaft shoulder, 24 positioning straight hole, 25 dovetail groove. DETAILED DESCRIPTION
[0025] The technical scheme provided by the utility model is described in more detail below. Figures 1-5
[0026] Referring to Figures 1 to 3 This utility model provides an adjustable inertia-capacity nonlinear vibration absorption device, including an upper outer shell 5, a lower outer shell 7, a ball screw inertia container, a linear spring damper 3, a connecting plate 4, and a connecting rod 9. The upper outer shell 5 is sleeved on the outside of the lower outer shell 7. Hinges 2 are symmetrically installed on the top of the upper outer shell 5. The hinges 2 are hinged to the upper end of the linear spring damper 3. The lower end of the linear spring damper 3 is connected to the connecting plate 4 through the hinges 2. The connecting plate 4 is connected to the inertia container shell of the ball screw inertia container through the connecting rod 9. The inertia container shell is a hollow cylinder, and a screw nut assembly is provided inside. A screw 10 is movably connected in the screw nut assembly. The hollow cylindrical inertia container shell has central holes at both its upper and lower ends, and the upper and lower ends of the screw 10 extend from these central holes respectively. The lower end of the lead screw 10 is fixed to the bottom of the lower outer shell 7 via a connecting sleeve 16 (if the bottom of the lower outer shell 7 is not closed, it can be closed via a lower shell cover 17, and the connecting sleeve 16 can be placed inside the lower shell cover 17, which is designed with an outer edge that matches the inner and outer diameters of the upper outer shell 5). The upper end of the lead screw 10 is fixed to the top of the lower outer shell 7 via a star-shaped member 6. Of course, the connection between the lead screw 10 and the lower outer shell 7 is not limited to the connecting sleeve 16 and the star-shaped member 6; other existing methods can also be used. When the linear spring damper 3 drives the connecting plate 4 to move up and down, thereby driving the connecting rod 9 and the inertial container shell to move up and down, the lead screw assembly will reciprocate around the lead screw 10.
[0027] In addition, an upper lifting lug 1 is provided on the top outer side of the upper outer shell 5, and correspondingly, a lower lifting lug 8 is provided on the bottom outer side of the lower outer shell 7 or on the outside of the lower shell cover 17.
[0028] See Figure 3 In some embodiments, the ball screw inertia container also includes a first tapered roller bearing 14 and a second tapered roller bearing 15 located at the upper and lower ends of the inertia container housing and sleeved on the screw nut assembly. When the inertia container housing moves up and down, it will push the corresponding first tapered roller bearing 14 or second tapered roller bearing 15 to move synchronously, thereby causing the screw nut assembly to reciprocate around the screw 10.
[0029] In some embodiments, the lead screw assembly includes a lead screw 18, a flange bushing 19, a slider 20, and a tension spring 22. The lead screw 18 and the flange bushing 19 are connected by bolts. The lead screw 10 is movably connected between the lead screw 18 and the flange bushing 19. The slider 20 is slidably disposed in a dovetail groove 25 on the flange bushing 19. One end of the tension spring 22 is connected to the flange bushing 19, and the other end is connected to the slider 20 to ensure that the slider 20 remains sliding in the dovetail groove 25 when subjected to centrifugal force. A positioning shoulder 23 is provided on the flange bushing 19, and the first tapered roller bearing 14 is disposed between the upper end of the inertia container housing and the positioning shoulder.
[0030] In some embodiments, the inertia container shell can include an inertia container upper shell cover 11, an inertia container lower shell cover 12 and an inertia container side wall 13, the inertia container upper shell cover 11 is bolted with the inertia container side wall 13, and the inertia container lower shell cover 12 is bolted with the inertia container side wall 13. The inertia container upper shell cover 11 and the inertia container lower shell cover 12 are provided with coaxial center holes. A first tapered roller bearing 14 is installed at the center hole of the inertia container upper shell cover 11, the outer ring of the first tapered roller bearing 14 is in contact with the inner surface of the positioning straight hole 24 of the inertia container upper shell cover 11, and the inner ring of the first tapered roller bearing 14 is in contact with the outer cylindrical surface of the flange shaft sleeve 19. The upper surface of the outer ring of the first tapered roller bearing 14 is in contact with the lower surface of the inertia container upper shell cover 11, and the lower surface of the inner ring of the first tapered roller bearing 14 is in contact with the upper positioning shaft shoulder 23 of the flange shaft sleeve 19.
[0031] Similarly, a second tapered roller bearing 15 is installed at the center hole of the inertia container lower shell cover 12, the outer ring of the second tapered roller bearing 15 is in contact with the inner surface of the positioning straight hole of the inertia container lower shell cover 12, and the inner ring of the second tapered roller bearing 15 is in contact with the outer cylindrical surface of the nut 18. The lower surface of the outer ring of the second tapered roller bearing 15 is in contact with the upper surface of the inertia container lower shell cover 12, and the upper surface of the inner ring of the second tapered roller bearing 15 is in contact with the flywheel surface of the nut 18 or the positioning shaft shoulder on the nut 18 (the positioning shaft shoulder on the nut 18 is not shown in the figure).
[0032] When the inertia container is subjected to external excitation, the upper lifting lug 1 and the lower lifting lug 8 are subjected to pressure, causing the upper outer shell 5 and the lower outer shell 7 to produce relative displacement. The piston rod inside the linear spring damper 3 drives the piston to reciprocate, generating viscous damping force to consume energy. The spring on the linear spring damper 3 produces a deformation angle of θ with the vertical direction, providing a nonlinear restoring force for the linear spring damper 3.
[0033] When the connecting plate 4 and the connecting rod 9 drive the inertia container to produce downward axial displacement, the inertia container upper shell cover 11 transmits the downward axial force to the upper surface of the outer ring of the first tapered roller bearing 14, the axial load on the upper surface of the outer ring of the first tapered roller bearing 14 is transmitted to the lower surface of the inner ring through the rolling body, and the lower surface transmits the axial force to the flange shaft sleeve 19, thereby driving the nut 18 and the flange shaft sleeve 19 to produce downward rotary motion along the lead screw 10.
[0034] When the connecting plate 4 and the connecting rod 9 drive the inertia container shell 13 to produce upward axial displacement, the inertia container side wall 13 transmits the upward axial force to the lower surface of the outer ring of the second tapered roller bearing 15, the lower surface of the outer ring of the second tapered roller bearing 15 transmits the axial load to the rolling body of the tapered roller bearing, and then to the upper surface of the inner ring and the nut 18, so as to drive the nut 18 and the flange shaft sleeve 19 to produce upward rotary motion along the screw rod 10.
[0035] When the nut 18 and the flange shaft sleeve 19 rotate upward and downward on the screw rod 10, the slider 20 slides outward along the dovetail groove 25 due to the centrifugal force. This sliding action causes the tensile spring 22 to deform, and further causes the position of the slider 20 in the dovetail groove 25 to change. Specifically, as the rotation speed of the nut 18 increases, the centrifugal force acting on the slider 20 also increases, causing the slider 20 to move further away from the rotation center line of the nut 18, thereby increasing the moment of inertia of the nut 18. Conversely, when the rotation speed of the nut 18 decreases, the centrifugal force acting on the slider 20 decreases, and under the action of the elastic force of the tensile spring 22, the slider 20 moves inward. Through this mechanism, the function of automatically adjusting the inertia of the inertia container according to the rotation speed is realized.
[0036] Mechanical and mathematical model of nonlinear spring force
[0037] In the utility model patent, the generation of nonlinear spring force is realized by linear springs and a central axis at an inclination angle θ, and the mechanical model is as shown in Figure 4 , wherein k0 and l0 are the stiffness coefficient and original length of the linear spring respectively; θ is the inclination angle of the linear spring with the horizontal direction; x is the displacement generated after the upper shell is subjected to force; at this time, the vertical component force of the two inclined linear springs is
[0038]
[0039] , wherein Taylor expansion of the above formula can obtain
[0040] F v = k1x + k3x 3 + O(x 5 ) (2)
[0041] k1 = 2k0 (1-l0 / l) - linear coefficient of nonlinear stiffness, unit: N / m;
[0042] j3 = k0l0 / l 3 - nonlinear coefficient of nonlinear stiffness, unit: N / m 3 ;
[0043] Similarly, the selected linear damper 3 generates a nonlinear damping force in the vertical direction as
[0044]
[0045] The Taylor expansion of the above formula can be obtained
[0046]
[0047] Wherein, c1=1 / l 2 is the linear coefficient of the nonlinear damping.
[0048] As can be seen from the mathematical expression (2) of the nonlinear spring force, the nonlinear spring force is realized by the linear spring in the inclined manner.In addition, the mathematical expression (2) of the nonlinear damping force is the function of the square of the relative velocity, and when the relative velocity between the upper and lower shells increases, the damping force increases nonlinearly with the increase of the relative velocity, so that the energy dissipation capacity of the nonlinear damper at a large speed can be effectively improved.
[0049] Mathematical relationship between the rotational inertia of the nut and the inertial capacity coefficient of the ball screw pair inertial container
[0050] The working principle of the ball screw inertial container in the utility model patent is as shown in Figure 5 The lead of the screw rod is L d , the total rotational inertia of the nut and the flywheel is I, the actual total mass is m0, and the rotation radius is r o The input end 1 is connected with the nut, the input end 2 is connected with the screw rod, when the two input ends are subjected to the exciting force, the two input ends generate different motion accelerations, according to the expression of the inertial force of Smith, the relationship between the force p between the two ends of the inertial container and the motion accelerations of the two ends can be expressed as
[0051]
[0052] Wherein, m in is the inertial capacity coefficient (the dimension is equivalent to the mass, also known as the inertial mass), and p is the inertial force; The acceleration of the two end points of the inertial container. Figure 5 The total rotational inertia of the nut and the flywheel is
[0053]
[0054] According to the kinetic energy equivalence principle, the equivalent translational mass is obtained, that is,
[0055]
[0056] Therefore, the force of the ball screw inertial container in the utility model is
[0057]
[0058] wherein the expression of the inertial coefficient of the ball screw inertial container is:
[0059] As can be seen from formula (7), the ball screw inertial container amplifies the inertia mass generated in the flywheel rotation process, so that the inertia mass of hundreds of kilograms can be realized with a smaller flywheel self weight. In the utility model, the centrifugal force of the sliding block in the rotation process is related to the rotation speed, the greater the rotation speed, the greater the centrifugal force, and the greater r o in formula (7), so that the inertial coefficient m in is also greater, which together with the nonlinear stiffness and the nonlinear damping can effectively realize and improve the vibration absorption performance of the inertial type nonlinear vibration absorption device.
[0060] Finally, it should be pointed out that: the above examples are only used to illustrate the technical solutions of the utility model, rather than limit them; although the utility model has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features, but 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 utility model.
Claims
1. A nonlinear vibration absorber of an inerter-adjustable type, characterized by, The device comprises an upper housing (5), a lower housing (7), a ball screw inertial container, a linear spring damper (3), a connecting plate (4) and a connecting rod (9), the upper housing (5) is sleeved outside the lower housing (7), a hinge (2) is symmetrically installed on the top of the upper housing (5), the hinge (2) is hingedly connected with the upper end of the linear spring damper (3), the lower end of the linear spring damper (3) is connected with the connecting plate (4) through the hinge (2), the connecting plate (4) is connected with the inertial container shell of the ball screw inertial container through the connecting rod (9), a nut assembly combination is arranged in the inertial container shell, a screw rod (10) is movably connected in the nut assembly combination, the lower end of the screw rod (10) is fixedly connected with the bottom of the lower housing (7), the upper end of the screw rod (10) is fixedly connected with the top of the lower housing (7), when the connecting rod (9) drives the inertial container shell to move up and down, the nut assembly combination will reciprocatingly rotate around the screw rod (10).
2. The inerter-tunable nonlinear vibration absorber of claim 1, wherein The ball screw inertial container further comprises a first tapered roller bearing (14) and a second tapered roller bearing (15) which are located at the upper and lower ends of the inertial container shell and are sleeved on the nut assembly combination, when the inertial container shell moves up and down, the corresponding first tapered roller bearing (14) or second tapered roller bearing (15) is pushed to move synchronously, so as to drive the nut assembly combination to reciprocatingly rotate around the screw rod (10).
3. The inerter-tunable nonlinear vibration absorber of claim 2, wherein The nut assembly combination comprises a nut (18) and a flange shaft sleeve (19) which is bolted with the nut (18), the screw rod (10) is movably connected in the nut (18) and the flange shaft sleeve (19), a positioning shaft shoulder (23) is arranged on the flange shaft sleeve (19), the first tapered roller bearing (14) is arranged between the upper end of the inertial container shell and the positioning shaft shoulder (23).
4. The inerter-tunable nonlinear vibration absorber of claim 3, wherein The nut assembly combination further comprises a sliding block (20) and a tension spring (22), the sliding block (20) is slidingly arranged in a dovetail groove (25) on the flange shaft sleeve (19), one end of the tension spring (22) is connected with the flange shaft sleeve (19), and the other end of the tension spring (22) is connected with the sliding block (20).
5. The inerter-tunable nonlinear vibration absorber of claim 1, wherein The device further comprises a lower housing cover (17), the lower housing cover (17) is provided with an outer edge, the inner and outer diameters of the outer edge are consistent with the inner and outer diameters of the upper housing (5).
6. The inerter-tunable nonlinear vibration absorber of claim 1, wherein An upper lifting lug (1) is arranged on the outside of the top of the upper housing (5), and a lower lifting lug (8) is arranged on the outside of the bottom of the lower housing (7).
7. The inerter-tunable nonlinear vibration absorber of claim 1, wherein The lower end of the screw rod (10) is fixedly connected with the bottom of the lower housing (7) through a connecting sleeve (16), and the upper end of the screw rod (10) is fixedly connected with the top of the lower housing (7) through a star-shaped piece (6), the center line of the star-shaped piece (6) is coaxial with the center line of the connecting sleeve (16).
8. The inerter-tunable nonlinear vibration absorber of claim 1, wherein The inertial container shell comprises an inertial container upper shell cover (11) and an inertial container lower shell cover (12) which are arranged at the upper and lower ends of the inertial container side wall (13), and the inertial container upper shell cover (11) and the inertial container lower shell cover (12) are provided with coaxial center holes for the upper and lower ends of the screw rod (10) to extend out.