A new load-adaptive quasi-zero stiffness vibration isolation system

Abstract

The present invention discloses a novel load-adaptive quasi-zero stiffness vibration isolation system, comprising: a first support frame; a second support frame, which is arranged parallel to and spaced apart from the first support frame; a first piston, one end of which is fixedly connected to the first support frame; a coil spring, one end of which is connected to the other end of the first piston; a second piston, one end of which is connected to the other end of the coil spring; a lifting mechanism, which is installed on the second support frame; a power output end of the lifting mechanism is connected to the other end of the second piston; a disc spring group, which is loosely sleeved on the coil spring; a mounting seat, which is arranged between the first support frame and the second support frame; a first groove, a second groove and a guide hole are coaxially arranged inside the mounting seat; the disc spring group is arranged in the first groove; one end of the first piston is matched and inserted into the first groove; the second groove is opened at the other end of the mounting seat, and the second piston is matched and arranged in the second groove; the two ends of the guide hole are respectively connected to the bottom of the first groove and the second groove.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration isolation, and in particular relates to a novel load-adaptive quasi-zero stiffness vibration isolation system. Background Art

[0002] In recent years, with the rapid development of science and technology and the improvement of material living standards, people's requirements for vibration environments have further increased, especially for low-frequency vibration. However, long-term exposure to low-frequency vibration environments not only affects the use of precision instruments, but also causes human fatigue, leading to various health and safety issues.

[0003] The linear vibration isolators in the existing technology have an inherent contradiction between high static load-bearing capacity and low starting vibration isolation frequency, and are unable to adjust their own vibration isolation performance according to load changes. Vibration isolation systems with adjustable functions have problems such as complex structure and difficult adjustment of vibration isolation performance. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a new load-adaptive quasi-zero stiffness vibration isolation system, which can solve the inherent contradiction between the high static load-bearing capacity and low starting vibration isolation frequency of the existing linear vibration isolation system, and at the same time can realize simple and adjustable vibration isolation performance.

[0005] The technical solution provided by the present invention is:

[0006] A new load-adaptive quasi-zero stiffness vibration isolation system, including:

[0007] a first support frame;

[0008] a second support frame, which is arranged parallel to and spaced apart from the first support frame;

[0009] a first piston, one end of which is fixedly connected to the first support frame;

[0010] a coil spring, one end of which is connected to the other end of the first piston;

[0011] a second piston, one end of which is connected to the other end of the coil spring;

[0012] a lifting mechanism fixedly mounted on the second support frame; a power output end of the lifting mechanism is connected to the other end of the second piston, driving the second piston to move toward or away from the first support frame;

[0013] a disc spring assembly, which is loosely mounted on the coil spring;

[0014] A mounting seat, which is arranged between the first supporting frame and the second supporting frame;

[0015] In which, the interior of the mounting seat has a coaxially arranged first groove, a second groove and a guide hole; the first groove is opened at one end of the mounting seat, and the disc spring group is arranged in the first groove; one end of the first piston is matched and inserted into the first groove, and can move axially along the first groove; the second groove is opened at the other end of the mounting seat, and the second piston is matched and arranged in the second groove, and can move axially along the second groove; the two ends of the guide hole are respectively connected to the bottom of the first groove and the second groove, and the cross-sectional size of the guide hole is smaller than the cross-sectional size of the first groove; the coil spring is located in the guide hole.

[0016] Preferably, the novel load-adaptive quasi-zero stiffness vibration isolation system further comprises:

[0017] The flange seat is fixedly connected to the second support frame; the flange seat is coaxially sleeved on the mounting seat and plays a guiding role for the mounting seat.

[0018] Preferably, the novel load-adaptive quasi-zero stiffness vibration isolation system further comprises:

[0019] A plurality of scissor-type guide mechanisms, one end of each scissor-type guide mechanism is connected to the first support frame, and the other end is connected to the second support frame.

[0020] Preferably, the bottom surface of the first groove is a conical surface.

[0021] Preferably, the disc spring group includes six disc springs, and the disc springs are arranged in a pair.

[0022] Preferably, the lifting mechanism includes:

[0023] a screw, one end of which is fixedly connected to the second piston;

[0024] Wherein, the second groove is a square groove, the cross section of the second piston is a square, and the size of the second piston matches the size of the second groove;

[0025] a first gear having an internal thread and being mounted on the screw rod through the internal thread;

[0026] a second gear meshing with the first gear for transmission;

[0027] The output end of the driving motor is connected to the second gear.

[0028] Preferably, the first gear is provided with a central through hole, a nut is fixed in the central through hole, and the first gear is matched and connected to the screw rod through the nut.

[0029] Preferably, the novel load-adaptive quasi-zero stiffness vibration isolation system further comprises:

[0030] a bearing cover plate, arranged parallel to and spaced apart from the second support frame;

[0031] Wherein, the second support frame is located between the first support frame and the bearing cover plate; the second gear is located between the bearing cover plate and the second support frame;

[0032] a first bearing mounted in the bearing cover plate;

[0033] The drive motor is mounted on the second support frame, the output shaft of the drive motor passes through the second support frame and is connected to the second gear, and the output shaft of the drive motor is supported in the first bearing.

[0034] Preferably, the novel load-adaptive quasi-zero stiffness vibration isolation system further comprises:

[0035] a second bearing mounted in the bearing cover plate;

[0036] One end of the nut extends to the outside of the first gear and is supported in the second bearing.

[0037] Preferably, the driving motor is a stepping motor.

[0038] The beneficial effects of the present invention are:

[0039] The novel load-adaptive quasi-zero stiffness vibration isolation system provided by the present invention has a simple and compact structure and is easy to assemble. It is suitable for occasions with small vertical space and is more convenient to install.

[0040] The novel load-adaptive quasi-zero stiffness vibration isolation system provided by the present invention can adjust the vibration isolation performance of the system according to load changes, effectively solving the problem of weakening of the vibration isolation performance of non-adjustable vibration isolation systems due to load changes.

[0041] The present invention solves the inherent contradiction between the high static load-bearing capacity and the low starting vibration isolation frequency of the traditional linear vibration isolation system, and at the same time realizes simple adjustment of the vibration isolation performance, requires less energy and has excellent vibration isolation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the overall structure of the load-adaptive quasi-zero stiffness vibration isolation system described in the present invention.

[0043] Figure 2 This is a cross-sectional view of the load-adaptive quasi-zero stiffness vibration isolation system described in the present invention.

[0044] Figure 3Schematic diagram of the structure of the mounting base of the present invention.

[0045] Figure 4 This is a schematic diagram of the transmission mechanism consisting of the first gear and the second gear according to the present invention.

[0046] Figure 5 Schematic diagram of force analysis of the vibration isolation system of the present invention.

[0047] Figure 6 This is the load-displacement characteristic curve of the vibration isolation system described in the present invention. DETAILED DESCRIPTION

[0048] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0049] like Figure 1-4 As shown, the present invention provides a novel load-adaptive quasi-zero stiffness vibration isolation system, which mainly includes: a mounting base 1, a coil spring 2, a disc spring group 8, a first support frame 11, a second support frame 10 and a jacking mechanism.

[0050] The first support frame 11 and the second support frame 10 are arranged horizontally, with the first support frame 11 located above the second support frame. Multiple scissor-type guide mechanisms 12 are provided between the first support frame 11 and the second support frame. The upper ends of the scissor-type guide mechanisms 12 are hinged to the first support frame 11 via cylinders, and the lower ends are connected to the second support frame 10 via embedded slide bars 13. The scissor-type guide mechanisms 12 provide motion guidance for the first and second support frames 11, 10.

[0051] The upper end of the first piston 9 is fixedly connected to the first support frame 11; the upper end of the coil spring 2 is connected to the lower end of the first piston 9. The upper end of the second piston 43 is connected to the lower end of the coil spring 2. The lifting mechanism is fixedly mounted on the second support frame 10; the power output end of the lifting mechanism is fixedly connected to the lower end of the second piston 43. The lifting mechanism can drive the second piston 43 to move up and down, causing the second piston 43 to move closer to or away from the first support frame 11, thereby causing the coil spring 2 to deform. Among them, the disc spring group 8 is loosely sleeved on the upper end of the coil spring 2.

[0052] The mounting base 1 is arranged between the first support frame 11 and the second support frame 10. Figure 3As shown, the interior of the mounting base has a coaxially arranged first groove 14, a second groove 16, and a guide hole 15. The first groove 14 is opened at the upper end of the mounting base 1, with the opening facing upward, and the disc spring group 8 is set in the first groove 14. The lower end of the first piston 9 is matched and inserted into the first groove 14 and can move axially along the first groove 14; the second groove 16 is opened at the lower end of the mounting base 1, with the opening facing downward, and the second piston 43 is matched and set in the second groove 16 and can move axially along the second groove 16; the two ends of the guide hole 15 are respectively connected to the bottom of the first groove 14 and the second groove 16, and the cross-section (horizontal cross-section) of the guide hole 15 is smaller than the cross-section of the first groove 14; the coil spring 2 is located in the guide hole 15, which is a cylindrical hole used to provide guidance for the deformation of the coil spring 2.

[0053] In this embodiment, the first piston 9 is fixedly connected to the upper first support frame 11 by a U-bolt 3, and the upper end of the coil spring 2 is hung on the bottom of the U-bolt 3. The first groove 14 is a cylindrical groove, and the corresponding first piston 9 is a cylindrical piston. The disc spring group 8 includes six disc springs, and the disc springs are arranged in a matched manner. The upper end of the disc spring group 8 rests on the first piston 9, and the lower end rests on the bottom surface of the first groove 14. By providing multiple disc springs, the deformation amount can be increased while the applied force remains unchanged. In actual applications, the combination of the disc springs and the number of disc springs can be adjusted according to needs.

[0054] Because the disc springs in the disc spring assembly 8 may flanging when subjected to excessive load, the bottom surface of the first groove 14 in the mounting seat 1 (i.e., the transition interface between the first groove 14 and the guide hole 15) for mounting the disc spring 8 is preferably configured as a conical surface to allow the disc spring to fully deform; wherein the slope of the conical surface is the same as the slope of the concave surface within the disc spring.

[0055] The lower end of the flange seat 7 has a cut edge that can be locked by bolts. The flange seat 7 is fixedly connected to the second support frame 10 by multiple bolts. Among them, the lower portion of the mounting base 1 is cylindrical in shape, and the flange seat 7 is sleeved on the lower portion of the mounting base 1 with an interference fit to limit the vertical and circumferential movement of the mounting base 1.

[0056] In this embodiment, the lifting mechanism mainly includes: a screw 41, a first gear 51, a second gear 53 and a drive motor 6. The drive motor 6 is a stepper motor. The screw 41 is coaxially arranged with the second piston 43, and the upper end of the screw 41 passes through the second support frame 10 and is welded to the lower end of the second piston 43. The second groove 16 is a square groove, the cross-section of the second piston 43 is square, and the cross-sectional dimensions of the second piston 43 match the cross-sectional dimensions of the second groove 16. The second piston 43 can only move axially in the second groove 16 and cannot rotate relative to the second groove 16. The second groove 16 serves as a guide for the axial movement of the second piston 43. The cross-sectional dimensions of the guide hole 15 are smaller than the cross-sectional dimensions of the second piston 43 (the second piston 43 cannot enter the guide hole 15), and the height of the second piston 43 is smaller than the height of the second groove 16, so that the second piston 43 can only move axially (up and down) in the second groove 16. In other embodiments, the height of the second piston 43 is the same as that of the second groove 16, and the cross-sectional dimensions of the guide hole 15 are larger than those of the second piston 43. When the second piston 43 moves upward, the upper end of the second piston 43 can enter the guide hole 15. The first gear 51 has an internally threaded hole at its center and is mounted on the screw 41 through the internally threaded hole. The second gear 53 meshes with the first gear 51 for transmission. The diameter of the first gear 51 is larger than that of the second gear.

[0057] A U-bolt 3 is fixedly connected to the second piston 43, and the lower end of the coil spring 2 is hooked on the U-bolt 3 connected to the second piston 43. The first gear 51 has a central through hole, and a nut 42 is welded in the central through hole. The first gear 51 is matched with the screw 41 through the nut 42.

[0058] A bearing cover plate 55 is provided below the second support frame 10, and the bearing cover plate 55 is arranged parallel to and spaced apart from the second support frame 10; the gear bearing cover plate 55 is fixedly connected to the second support frame 10 by an angle steel fitting 56. The first gear 51 and the second gear 53 are both located between the bearing cover plate 55 and the second support frame 10. The first bearing 54 is installed in the bearing cover plate 55; the drive motor 6 is installed on the second support frame 10, and the output shaft of the drive motor 6 vertically passes through the second support frame 10 and is connected to the second gear 53 by a shaft key to drive the second gear 53 to rotate; the lower end of the output shaft of the drive motor 6 is supported in the first bearing 54. The second bearing 52 is installed in the bearing cover plate 55; the lower end of the nut 42 extends to the outside of the first gear 51 and is supported in the second bearing 52. The bearing cover plate 55 is provided with a through hole at the lower end of the corresponding screw rod 41, and the lower end of the screw rod 41 can move up and down through the through hole.

[0059] As a preference, a third bearing 57 is installed in the second support frame 10 , and the upper end of the first gear 51 extends upward to form a cylindrical connecting portion, and the upper end of the first gear 51 is supported in the third bearing 57 through the cylindrical connecting portion.

[0060] In one embodiment, the first bearing 54 is a deep groove ball bearing, and the second bearing 52 and the third bearing 57 are tapered roller bearings. In actual use, the type of bearings used can be reasonably adjusted according to the change in the force.

[0061] When the drive motor 6 outputs power, it drives the second gear 53 to rotate, driving the first gear 51 to rotate. Since the first gear 51 cannot move axially, and the screw 41 is connected to the second piston 43 and cannot rotate, the screw 41 is subjected to the reaction force of the spiral pair to move axially, thereby changing the initial deformation of the spiral spring 2, and ultimately improving the vibration isolation performance of the quasi-zero stiffness system 100.

[0062] When there is no vertical load on the system, the disc spring 8 and the coil spring 2 are both in the initial state, that is, no force is generated. When a vertical load is applied to the system, the drive motor 6 outputs power, which is converted into the axial movement (vertical direction) of the second piston 43 through the jacking mechanism 4, thereby causing the coil spring 2 to generate an initial force, and ultimately causing the movement of the zero stiffness position point. When the system bears a load change, the electrical signal generated by the pressure sensor provided on the first support frame 11 can be used to determine the number of rotations of the stepper motor 6 shaft, so that the screw 41 produces a certain axial displacement, thereby generating a force on the coil spring 2, so that the system is always in the zero stiffness position point. During the entire working process, the disc spring group 8 is always in a compressed state, and the coil spring 2 is always in a stretched state, which effectively meets the low-frequency vibration isolation requirements under different load-bearing mass conditions.

[0063] like Figure 5 As shown in the figure, the y-axis direction is the width direction of the vibration isolation system, and the z-axis direction is the vertical load direction.

[0064] The quasi-zero stiffness vibration isolation system includes a positive stiffness coil spring 2 and a negative stiffness disc spring 8. The upper part of the system is connected to the vibration isolation equipment through a first support frame 11, and the lower part is fixed by an angle steel fitting 56. The differential of the vertical force transmitted upward by the system to the displacement is negative stiffness. After the coil spring 2 and the disc spring 8 are connected in parallel, the system has the characteristics of high static stiffness and low dynamic stiffness.

[0065] When the vibration isolation system is applied between the vehicle body and the ground, the coil spring 2 and the disc spring 8 jointly provide a vertical force, which can be expressed as:

[0066]

[0067] In order to simplify the above formula, let Substitute and simplify as follows:

[0068]

[0069] After differentiating f from the above formula, the expression of the stiffness k of the quasi-zero stiffness vibration isolation system can be obtained as:

[0070]

[0071]

[0072] Where n is the number of disc springs, E is the elastic modulus of the disc spring, μ is the Poisson's ratio, t is the thickness of the disc spring, f is the deformation of the quasi-zero stiffness vibration isolation system at any time, h0 is the deformation of the disc spring when it is flattened, k z is the stiffness of the coil spring, D is the outer diameter of the disc spring, d is the inner diameter of the disc spring, C is the ratio of the outer diameter to the inner diameter, that is, C = D / d, α, β, K1 are constants.

[0073] According to the expressions of F and k and the related parameters that have been designed, the load-displacement characteristic curve of the quasi-zero stiffness vibration isolation system can be obtained, as shown in Figure 6 As shown, it is easy to know that when the system is near the equilibrium position, the dynamic stiffness of the vibration isolation system is close to zero. It can be seen that the system has the characteristics of high static and low dynamic stiffness.

[0074] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A new load-adaptive quasi-zero stiffness vibration isolation system, characterized in that: include: a first support frame; a second support frame, which is arranged parallel to and spaced apart from the first support frame; a first piston, one end of which is fixedly connected to the first support frame; a coil spring, one end of which is connected to the other end of the first piston; a second piston, one end of which is connected to the other end of the coil spring; a lifting mechanism fixedly mounted on the second support frame; a power output end of the lifting mechanism is connected to the other end of the second piston, driving the second piston to move toward or away from the first support frame; a disc spring assembly, which is loosely mounted on the coil spring; A mounting seat, which is arranged between the first supporting frame and the second supporting frame; The mounting seat has a first groove, a second groove, and a guide hole coaxially arranged therein; the first groove is provided at one end of the mounting seat, and the disc spring assembly is provided in the first groove; one end of the first piston is matched and inserted into the first groove and can move axially along the first groove; the second groove is provided at the other end of the mounting seat, and the second piston is matched and provided in the second groove and can move axially along the second groove; both ends of the guide hole are respectively connected to the bottom of the first groove and the second groove, and the cross-sectional dimension of the guide hole is smaller than the cross-sectional dimension of the first groove; the coil spring is located in the guide hole; The upper end of the disc spring group abuts against the first piston, and the lower end abuts against the bottom surface of the first groove; During the entire working process, the disc spring group is always in a compressed state, and the coil spring is always in a stretched state; The jacking mechanism comprises: a screw, one end of which is fixedly connected to the second piston; Wherein, the second groove is a square groove, the cross section of the second piston is a square, and the size of the second piston matches the size of the second groove; a first gear having an internal thread and being mounted on the screw rod through the internal thread; a second gear meshing with the first gear for transmission; a driving motor, an output end of which is connected to the second gear; When the system is subjected to load changes, the number of rotations of the drive motor shaft is determined by the electrical signal generated by the pressure sensor installed in the first support frame, causing the screw to produce a certain axial displacement, thereby generating a force on the coil spring, so that the system is always at the zero stiffness position point.

2. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 1 is characterized in that: Also includes: The flange seat is fixedly connected to the second support frame; the flange seat is coaxially sleeved on the mounting seat and plays a guiding role for the mounting seat.

3. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 2 is characterized in that: Also includes: A plurality of scissor-type guide mechanisms, one end of each scissor-type guide mechanism is connected to the first support frame, and the other end is connected to the second support frame.

4. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 3 is characterized in that: The bottom surface of the first groove is a conical surface.

5. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 3 or 4, characterized in that: The disc spring group includes six disc springs, and the disc springs are arranged in a pair.

6. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 5 is characterized in that: The first gear is provided with a central through hole, a nut is fixedly installed in the central through hole, and the first gear is matched and connected to the screw rod through the nut.

7. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 6 is characterized in that: Also includes: a bearing cover plate, arranged parallel to and spaced apart from the second support frame; Wherein, the second support frame is located between the first support frame and the bearing cover plate; the second gear is located between the bearing cover plate and the second support frame; a first bearing mounted in the bearing cover plate; The drive motor is mounted on the second support frame, the output shaft of the drive motor passes through the second support frame and is connected to the second gear, and the output shaft of the drive motor is supported in the first bearing.

8. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 7 is characterized in that: Also includes: a second bearing mounted in the bearing cover plate; One end of the nut extends to the outside of the first gear and is supported in the second bearing.

9. The novel load-adaptive quasi-zero stiffness vibration isolation system according to claim 8 is characterized in that: The driving motor is a stepping motor.

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