A vibration isolation method and a vibration isolation base with time-varying position of a vibration isolator

Abstract

The application discloses a position time-varying vibration isolator and a vibration isolation base, and belongs to the technical field of vibration isolation. The vibration isolation base comprises a bearing elastic plate and a position time-varying vibration isolator assembly installed at the bottom of the bearing elastic plate. The position time-varying vibration isolator assembly comprises fixed vibration isolators and a movable vibration isolator. The fixed vibration isolators are distributed in a circumferential direction along the bottom surface of the bearing elastic plate, and one end of each fixed vibration isolator is detachably fixedly connected with the bearing elastic plate, and the other end is detachably fixedly connected with a vibration-isolated structure. The movable vibration isolator is slidably connected to the bottom surface of the bearing elastic plate and can move along a track parallel to the bearing elastic plate, so that the position of the movable vibration isolator is time-varying relative to the bearing elastic plate. The application solves the defects of low-frequency vibration isolation performance and high resonance peak transmissibility of the vibration isolator.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of vibration isolation, and particularly relates to a vibration isolation method and a vibration isolation base with time-varying position of a vibration isolator. BACKGROUND

[0002] The power device in a system is a common vibration source, and vibration can cause a series of hazards such as fatigue damage to the structure, affect the working accuracy, and reduce the system stability, and even reduce the service life of the system, so the installation of the power device often needs a vibration isolation device to reduce vibration transmission. The traditional vibration isolator has good vibration isolation effect at medium and high frequencies, and the action frequency band is related to the resonance frequency, and has vibration isolation effect at a frequency band of more than twice the resonance frequency, and will amplify vibration near the resonance frequency. A lower resonance frequency needs a smaller stiffness of the vibration isolator, and it is difficult to support a power device with a larger mass, so low-frequency vibration isolation has always been a difficulty in vibration control. The working state of the power device is often dynamically changing, and when the excitation frequency is close to the resonance frequency, the vibration will be amplified. Therefore, a vibration isolation method that focuses on low-frequency vibration isolation performance and can adapt to changes in excitation frequency is needed.

[0003] In order to improve the low-frequency performance of the vibration isolator and reduce the peak vibration transmissibility, a commonly used scheme is a quasi-zero stiffness vibration isolator. The low-frequency quasi-zero stiffness vibration isolator disclosed in the prior art integrates a double-geometric nonlinear structure, uses the high static and low dynamic characteristics of nonlinear stiffness to improve the low-frequency vibration isolation performance while ensuring the carrying capacity, and widens the quasi-zero stiffness interval through double-geometric nonlinear structure integration design. The multi-degree-of-freedom low-frequency vibration isolator based on vibration modal and swing modal coupling combines a high static and low dynamic stiffness vibration isolator with a spatial swing, moves the vibration isolation interval to a low frequency, and realizes multi-degree-of-freedom vibration isolation. The current quasi-zero stiffness vibration isolator can balance the carrying capacity and low-frequency vibration isolation performance of the vibration isolation structure, but it is difficult to suppress the vibration transmission of the resonance peak. SUMMARY

[0004] The technical problem to be solved is:

[0005] In order to avoid the shortcomings of the prior art, the present application provides a vibration isolation method and a vibration isolation base with time-varying position of a vibration isolator. The vibration isolation base connects the vibration isolator through an elastic plate as a carrying platform to form double-layer vibration isolation, reduce the natural frequency, and not affect the carrying capacity. The time-varying resonance frequency of the vibration isolation base is generated by the time-varying position of the vibration isolator, the resonance state is destroyed, a part of the steady-state response is caused by the transient vibration, and the resonance transmissibility of the vibration isolator is reduced. The present application solves the defects of low-frequency vibration isolation performance of the vibration isolator and high resonance peak transmissibility.

[0006] The technical scheme of the present application is: a vibration isolation method with time-varying position of a vibration isolator, characterized by the following specific steps:

[0007] Step 1: arranging a double-layer vibration isolation base;

[0008] The double-layer vibration isolation base is a component connected between the equipment and the foundation to eliminate vibration transmission, comprising a bearing elastic plate and a position time-varying isolator assembly installed at the bottom of the bearing elastic plate.

[0009] Step 2: Adjust the position distribution of the position time-varying isolator assembly to generate position time variation, so as to realize time variation of the natural frequency and mode of the vibration isolation base.

[0010] A further technical solution of the present application is that the position time-varying isolator assembly comprises a fixed isolator and a moving isolator, and the moving isolator is driven by a power source to move along a track parallel to the bearing elastic plate.

[0011] A further technical solution of the present application is that the moving isolator continuously moves at a constant speed according to a set speed.

[0012] A further technical solution of the present application is that the moving track of the moving isolator is a straight line.

[0013] A vibration isolation base with time-varying isolator position, characterized in that it comprises a bearing elastic plate and a position time-varying isolator assembly installed at the bottom of the bearing elastic plate; the position time-varying isolator assembly comprises a fixed isolator and a moving isolator.

[0014] A plurality of the fixed isolators are distributed circumferentially along the bottom surface of the bearing elastic plate, one end of each fixed isolator is detachably fixedly connected with the bearing elastic plate, and the other end is detachably fixedly connected with a structure to be isolated.

[0015] The moving isolator is slidingly connected to the bottom surface of the bearing elastic plate and can move along a track parallel to the bearing elastic plate, so that the position of the moving isolator is time-varying relative to the bearing elastic plate.

[0016] A further technical solution of the present application is that the number of the fixed isolators is three, and the moving isolator is distributed circumferentially at four support positions of the bearing elastic plate.

[0017] A further technical solution of the present application is that the sliding track of the moving isolator is located at the edge of the bearing elastic plate and reciprocally slides from a support position to an adjacent fixed isolator, or is located in the radial direction of the bearing elastic plate and reciprocally slides from a support position to the midpoint of the bearing elastic plate.

[0018] A further technical solution of the present application is that the power source is a hydraulic cylinder, the piston rod of the hydraulic cylinder is connected to the moving isolator through a connecting rod, and the hydraulic cylinder controls the reciprocating movement of the moving isolator along the sliding track.

[0019] A further technical solution of the present application is that the isolator is selected from a spring isolator or a rubber isolator; and the two ends of the moving isolator are respectively installed on the bearing elastic plate and the structure to be isolated through a sliding block guide rail mechanism.

[0020] The further technical scheme of the present application is that the bearing elastic plate is made of elastic metal material, and the thickness ranges from 1mm to 5mm.

[0021] Beneficial effects

[0022] The beneficial effects of the present application are that the vibration isolation base with the vibration isolator position time-varying design can form double-layer vibration isolation, and the inherent frequency can be reduced without reducing the stiffness of the vibration isolator, so that the low-frequency vibration isolation range is widened while the high bearing capacity is ensured.

[0023] 1. The vibration isolation base with the vibration isolator position time-varying design can form double-layer vibration isolation, and the inherent frequency can be reduced without reducing the stiffness of the vibration isolator, so that the low-frequency vibration isolation range is widened while the high bearing capacity is ensured.

[0024] 2. The vibration isolation base with the vibration isolator position time-varying design can form double-layer vibration isolation, and the inherent frequency can be reduced without reducing the stiffness of the vibration isolator, so that the low-frequency vibration isolation range is widened while the high bearing capacity is ensured.

[0025] 3. The vibration isolator position time-varying design can produce energy dispersion effect in the frequency domain, and can provide additional damping effect.

[0026] 4. The present application uses hydraulic cylinders to push the vibration isolator to move at a constant speed on the slide rail, without the need for additional algorithm control, and has the characteristics of simple structure design, strong operability and good stability. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a structure diagram of the vibration isolation base with the vibration isolator position time-varying design.

[0028] Figure 2 It is a schematic diagram of the connection mode of the moving vibration isolator.

[0029] Figure 3 It is a structure top view of the vibration isolation base with the vibration isolator in three moving modes.

[0030] Figure 4 It is a vibration transmission coefficient comparison diagram of the conventional vibration isolator and the vibration isolation base with the vibration isolator position fixed.

[0031] Figure 6 It is the first-order vibration mode of the vibration isolation base.

[0032] Figure 5 shows a comparison of the vibration response of a vibration isolation base with a fixed vibration isolator position and a vibration isolation base with a time-varying vibration isolator position.

[0033] Explanation of reference numerals in the attached drawings: 1. Load-bearing elastic plate; 2. Fixed vibration isolator; 3. Movable vibration isolator; 4. Connecting rod; 5. Telescopic hydraulic cylinder; 6. Slider; 7. Guide rail. Detailed Implementation

[0034] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] Reference Figures 1 to 3 As shown in the figure, this embodiment provides a vibration isolation base with a time-varying vibration isolator position. The vibration isolation base includes a load-bearing elastic plate 1, a fixed vibration isolator 2, a movable vibration isolator 3, a telescopic hydraulic cylinder 5, a guide rail 6, and a slider 7.

[0037] The bearing elastic plate 1 is a thin metal elastic plate, which can be made of various elastic metal materials such as iron, aluminum, and copper; its thickness ranges from 1mm to 5mm, and the lower surface is fixedly connected to the guide rail and the upper slider of the movable vibration isolator.

[0038] The fixed vibration isolator 2 is fixedly connected to the bearing elastic plate 1 and the vibration-isolated structure at both ends, respectively; the guide rail 6 is installed on the lower surface of the elastic bearing plate 1, and the guide rail 6 of the same length is installed at the corresponding position of the vibration-isolated structure directly below it; the movable vibration isolator is connected to the slider 7 at both ends, and is installed on the guide rail 6 on the surface of the bearing elastic plate and the vibration-isolated structure; the movable vibration isolator is horizontally connected to the telescopic hydraulic cylinder 5 through the connecting rod.

[0039] One end of each of the three fixed vibration isolators 2 is fixedly connected to the three corners of the bearing elastic plate, and the other end is fixedly connected to the structure being isolated.

[0040] A movable vibration isolator 3 has sliders 7 installed at both ends. One end is connected to the guide rail 6 that carries the elastic plate, and the other end is connected to the guide rail 6 of the structure being isolated. A hydraulic cylinder is connected radially in the middle position. The hydraulic cylinder can control the position of the vibration isolator to move uniformly along the guide rail.

[0041] The three fixed vibration isolators and one mobile vibration isolator can be the same base vibration isolator, or a variety of base vibration isolators such as spring vibration isolators or rubber vibration isolators can be selected.

[0042] The guide rail direction of the movable vibration isolator can be a straight line at any angle on the horizontal plane, and the optimal guide rail direction is selected according to the vibration mode of the mode of interest.

[0043] This embodiment presents a vibration isolation method with a time-varying vibration isolator position, the specific steps of which are as follows:

[0044] Step 1: Install double-layer vibration isolation bases;

[0045] The double-layer vibration isolation base is a component that connects the equipment and the foundation to eliminate vibration transmission, including a load-bearing elastic plate 1 and a position-varying vibration isolator assembly installed at its bottom;

[0046] Step 2: Adjust the position distribution of the position-time-varying vibration isolator assembly to generate position time-varying characteristics, thereby achieving time-varying natural frequencies and mode shapes of the vibration isolation base. In this embodiment, the position-time-varying vibration isolator assembly consists of three fixed vibration isolators 2 and one movable vibration isolator 3.

[0047] In this embodiment, the natural frequency of the vibration isolation base is reduced by a combined support method of vibration isolators and elastic bearing plates. The telescopic hydraulic cylinder 5 is controlled to move the vibration isolator 3 along the guide rail during operation, providing a time-varying resonant frequency. The installation direction of the guide rail can be as follows: Figure 3 The coordinates of the vibration isolator 3 corresponding to the three methods shown are (0.37-0.15t, 0.27), (0.37, 0.27-0.1t), and (0.37-0.15t, 0.27-0.1t).

[0048] To further illustrate the effectiveness of this method, we will now compare and analyze the calculation results using conventional spring isolators, isolator-fixed vibration isolation bases, and isolator-time-varying vibration isolation bases.

[0049] When the parameters of the conventional spring vibration isolator and the two types of vibration isolation bases are the same, the comparison results of the transmission coefficients of the conventional spring vibration isolator and the vibration isolation base with fixed vibration isolator position are as follows: Figure 4 As shown in Figure 5, the vibration response of the vibration isolator with a fixed position and the vibration isolator with a time-varying position are compared. Figure 4The harmonic response calculation results show that, compared with conventional spring vibration isolation, the natural frequency and resonance peak value of the designed vibration isolation base are significantly reduced. Figure 5 shows that time-varying the position of the isolator can further reduce the resonance peak value of the vibration isolation base, indicating that the time-varying position of the isolator in the vibration isolation base can improve low-frequency vibration isolation performance while suppressing resonance energy transfer. For the first natural frequency with severe resonance, the first and third time-varying methods have significantly better suppression effects on the resonance peak value than the second method. The selection of the time-varying trajectory needs to be determined based on the mode shape of the mode of interest. In this implementation case, the mode shape of the first natural frequency of the vibration isolation base is as follows: Figure 6 As shown, the movement of the vibration isolator 3 along its length has a more significant impact on the system's natural frequency.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A vibration isolation method with time-varying vibration isolator position, characterized in that... The specific steps are as follows: Step 1: Install double-layer vibration isolation bases; The double-layer vibration isolation base is a component that connects the equipment and the foundation to eliminate vibration transmission, including a load-bearing elastic plate and a time-varying vibration isolator assembly installed at its bottom. Step 2: Adjust the position distribution of the position-time-varying vibration isolator components to generate position time-varying, thereby realizing time-varying of the natural frequency and mode shape of the vibration isolation base; The position-varying vibration isolator assembly includes a fixed vibration isolator and a movable vibration isolator, and the movable vibration isolator is driven by a power source to move along a trajectory parallel to the load-bearing elastic plate.

2. The vibration isolation method with time-varying vibration isolator position according to claim 1, characterized in that: The movable vibration isolator moves continuously at a constant speed according to the set speed.

3. The vibration isolation method with time-varying vibration isolator position according to claim 1, characterized in that: The movement trajectory of the movable vibration isolator is a straight line.

4. A vibration isolation base with a time-varying vibration isolator position, used to perform the vibration isolation method with a time-varying vibration isolator position as described in any one of claims 1-3; characterized in that: It includes a load-bearing elastic plate and a position-time-varying vibration isolator assembly installed at its bottom; the position-time-varying vibration isolator assembly includes a fixed vibration isolator and a movable vibration isolator; Multiple fixed vibration isolators are distributed circumferentially along the bottom surface of the bearing elastic plate, with one end detachably and fixedly connected to the bearing elastic plate and the other end detachably and fixedly connected to the vibration isolating structure. The movable vibration isolator is slidably connected to the bottom surface of the bearing elastic plate and can move along a trajectory parallel to the bearing elastic plate, causing its position relative to the bearing elastic plate to change over time.

5. The vibration isolation base with time-varying vibration isolator position according to claim 4, characterized in that: The number of fixed vibration isolators is three, which, together with the movable vibration isolators, are distributed circumferentially at the four support positions of the bearing elastic plate; the trajectory of the movable vibration isolators is a straight line at any angle in the horizontal plane.

6. The vibration isolation base with time-varying vibration isolator position according to claim 4, characterized in that: The sliding trajectory of the movable vibration isolator is located at the edge of the bearing elastic plate, and slides back and forth from the support position to the adjacent fixed vibration isolator; or it is located in the radial direction of the bearing elastic plate, and slides back and forth from the support position to the midpoint of the bearing elastic plate.

7. The vibration isolation base with time-varying vibration isolator position according to claim 4, characterized in that: The power source is a hydraulic cylinder, whose piston rod is connected to the movable vibration isolator through a connecting rod. The hydraulic cylinder controls the movable vibration isolator to move back and forth along the sliding trajectory.

8. The vibration isolation base with time-varying vibration isolator position according to claim 4, characterized in that: The vibration isolator is selected from spring vibration isolators or rubber vibration isolators; the two ends of the movable vibration isolator are respectively installed on the bearing elastic plate and the vibration isolated structure through a slider guide mechanism.

9. A vibration isolation base with time-varying vibration isolator position according to any one of claims 4-8, characterized in that: The load-bearing elastic plate is made of elastic metal material with a thickness ranging from 1 mm to 5 mm.

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