A semi-active vibration isolation device with a passive negative stiffness mechanism

Abstract

The application provides a kind of main and passive vibration isolation device with passive negative stiffness mechanism, specifically relates to reducing the influence of internal and external vibration sources on precision equipment, belongs to the field of vibration control.The device includes rack, load tray, multidirectional stiffness component, horizontal stiffness mechanism, vertical stiffness mechanism, magnetic spring and actuator component, magnetic spring, actuation and guide mechanism, z-direction guide rail slider module, z-direction motion platform, y-direction guide rail slider module, y-direction motion platform, x-direction guide rail slider module, vertical actuator, horizontal actuator, coupling mechanism, vibration sensor, measurement and control system, driving system.The application utilizes passive negative stiffness mechanism, reduces actuator output and size while enhancing active vibration suppression capability, simplifies the design of vibration isolator, can reduce the manufacturing and maintenance cost of main and passive vibration isolator, saves equipment installation space, and has a resisting effect on ground vibration and various vibrations of precision equipment.

Description

Technical Field

[0001] This invention provides an active and passive vibration isolation device with a passive negative stiffness mechanism, specifically relating to reducing the impact of internal and external vibration sources on precision equipment, and belonging to the field of vibration control. Background Technology

[0002] Currently, precision equipment widely employs vibration isolation devices to bear its own weight and resist various vibrations. Among them, passive vibration isolation devices can effectively attenuate ground vibrations. However, the protective effect of passive vibration isolation devices is relatively limited against other vibration sources inside and outside the equipment, such as cables and pipelines connected to the outside, and moving parts of the equipment itself. Therefore, in situations with complex environmental vibrations and high vibration protection requirements, sensors and actuators are often added to passive vibration isolation devices to form active-passive vibration isolation devices, which actively sense and suppress vibrations. However, traditional active-passive vibration isolation devices require high-output, large-size actuators to ensure the effectiveness of active vibration suppression, resulting in a trade-off between performance and power consumption, manufacturing and maintenance costs, and size. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention provides an active-passive vibration isolation device with a passive negative stiffness mechanism. This invention is achieved through the following technical solution:

[0004] A passive vibration isolation device with a passive negative stiffness mechanism includes a frame 1, a load tray 2, a multi-directional stiffness component 3, a magnetic spring and actuator assembly 4, a coupling mechanism 5, a vibration sensor 6, a measurement and control system 7, and a drive system 8.

[0005] The multi-directional stiffness component 3 includes a horizontal stiffness mechanism 3-1 and a vertical stiffness mechanism 3-2;

[0006] The magnetic spring and actuator assembly 4 includes a magnetic spring 4-1 and an actuation and guiding mechanism 4-2.

[0007] The actuation and guiding mechanism 4-2 includes a z-axis guide rail slider module 4-2-1, a z-axis motion platform 4-2-2, a y-axis guide rail slider module 4-2-3, a y-axis motion platform 4-2-4, an x-axis guide rail slider module 4-2-5, a vertical actuator 4-2-6, and a horizontal actuator 4-2-7.

[0008] The frame 1 is fixed to the ground and is at a certain height above the ground. Under the constraint of the actuation and guiding mechanism 4-2, the load tray 2 has three degrees of freedom of movement relative to the frame 1 in the x, y and z directions.

[0009] The load tray 2 is connected to various protected objects, i.e. precision equipment, and transmits their gravity to the coupling mechanism 5. The coupling mechanism 5 transmits gravity to the frame 1 through the vertical stiffness mechanism 3-2 and the horizontal stiffness mechanism 3-1, and the frame 1 transmits gravity to the ground.

[0010] The vertical actuator 4-2-6 is disposed between the frame 1 and the z-axis motion platform 4-2-2, driving the z-axis motion platform 4-2-2 along the z-axis; the horizontal actuator 4-2-7 is disposed between the z-axis motion platform 4-2-2 and the y-axis motion platform 4-2-4, driving the y-axis motion platform 4-2-4 along the y-axis; the horizontal actuator 4-2-7 is also disposed between the y-axis motion platform 4-2-4 and the load tray 2, driving the load tray 2 along the x-axis;

[0011] Under the constraint of the actuation and guiding mechanism 4-2, the magnetic interaction inside the magnetic spring 4-1 manifests in three directions: x, y, and z. It exhibits negative stiffness in the z direction and positive stiffness in the x and y directions. The horizontal stiffness mechanism 3-1 exhibits negative stiffness in the x and y directions, while the vertical stiffness mechanism exhibits positive stiffness in the z direction. Under the combined action of the multi-directional stiffness component 3 and the magnetic spring 4-1, the stiffness between the load tray 2 and the frame 1 is positive in the x, y, and z directions, thus providing passive vibration isolation capability.

[0012] The negative stiffness of the horizontal stiffness mechanism 3-1 in the x and y directions is between 0.4 and 0.7 times the positive stiffness of the magnetic spring 4-1 in the corresponding directions; the negative stiffness of the magnetic spring 4-1 in the z direction is between 0.4 and 0.7 times the positive stiffness of the vertical stiffness mechanism 3-2 in that direction.

[0013] The coupling mechanism 5 has multiple rotational degrees of freedom, allowing the load tray 2 to rotate freely within a small range relative to the vertical stiffness mechanism 3-2 without restriction; under the action of the coupling mechanism 5, the movement of the multi-directional stiffness component 3 and the magnetic spring and actuator component 4 do not conflict and their functions do not interfere with each other;

[0014] The vibration sensor 6 is installed on the bottom surface of the load tray 2. The original vibration signal measured is converted into a vibration control signal by the measurement and control system 7. The vibration control signal is then converted into a drive signal for the vertical actuator 4-2-6 and the horizontal actuator 4-2-7 by the drive system 8, which actively suppresses the vibration of the load tray 2 and the protected object.

[0015] The negative stiffness of the horizontal stiffness mechanism 3-1 in the x and y directions assists the vibration suppression function of the horizontal actuator 4-2-7; the negative stiffness of the magnetic spring 4-1 in the z direction assists the vibration suppression function of the vertical actuator 4-2-6.

[0016] The advantages of this invention are:

[0017] (1) While enhancing the active vibration suppression effect, the actuator output and size are reduced, thereby reducing the power consumption and manufacturing and maintenance costs of the active and passive vibration isolation devices and saving equipment installation space;

[0018] (2) The design of the vibration isolation device is simplified by using a three-degree-of-freedom magnetic spring;

[0019] (3) It has the effect of resisting ground vibration and various vibrations of precision equipment itself. Attached Figure Description

[0020] Figure 1 This is a schematic diagram showing the main components and connection relationships of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the present invention excluding the measurement and control system 7 and the drive system 8. The section is cut to show the obscured structure.

[0022] Figure 3 The diagram shows the arrangement of the magnetic spring 4-1 and the horizontal actuator 4-2-7. It is a top view after removing the load tray 2 and the vibration sensor 6.

[0023] The diagram shows: frame 1, load tray 2, horizontal stiffness mechanism 3-1, vertical stiffness mechanism 3-2, magnetic spring 4-1, z-axis guide rail slider module 4-2-1, z-axis motion platform 4-2-2, y-axis guide rail slider module 4-2-3, y-axis motion platform 4-2-4, x-axis guide rail slider module 4-2-5, vertical actuator 4-2-6, horizontal actuator 4-2-7, coupling mechanism 5, and vibration sensor 6. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The described embodiments are merely one embodiment of the present invention, wherein: the number of horizontal stiffness mechanisms 3-1 is 3, the number of vertical stiffness mechanisms 3-2 is 1, the number of magnetic springs 4-1 is 4, the number of z-guide rail slider modules 4-2-1 is 4, the number of y-guide rail slider modules 4-2-3 is 2, the number of x-guide rail slider modules 4-2-5 is 2, the number of vertical actuators 4-2-6 is 2, the number of horizontal actuators 4-2-7 is 4, and the number of vibration sensors 6 is 1; the horizontal stiffness mechanism 3-1, the vertical vibration isolation component 3-2, and the coupling mechanism 5 are connected sequentially from the frame 1 to the load tray 2; the guide rail slider modules of the actuation and guiding mechanism 4-2 are, from the frame 1 to the load tray 2, z-guide rail slider modules 4-2-1, y-guide rail slider modules 4-2-3, and x-guide rail slider modules 4-2-5. Based on the embodiments of the present invention, or embodiments that only change the number of horizontal stiffness mechanisms, vertical stiffness mechanisms, magnetic springs, z-axis guide rail slider modules, y-axis guide rail slider modules, x-axis guide rail slider modules, vertical actuators, horizontal actuators, and vibration sensors; embodiments that only change the connection order of the horizontal stiffness mechanism, vertical stiffness mechanism, and coupling mechanism; and embodiments that only change the arrangement order of the z-axis guide rail slider modules, y-axis guide rail slider modules, and x-axis guide rail slider modules in the actuation and guiding mechanism, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0025] In the description of this invention, it should be noted that the terms "upper", "lower", "left", "right", "horizontal plane", "vertical direction", "x-direction", "y-direction", "z-direction", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of this invention.

[0026] A passive vibration isolation device with a passive negative stiffness mechanism comprises a frame 1, a load tray 2, a multi-directional stiffness assembly 3, a horizontal stiffness mechanism 3-1, a vertical stiffness mechanism 3-2, a magnetic spring and actuator assembly 4, a magnetic spring 4-1, an actuation and guiding mechanism 4-2, a z-axis guide rail slider module 4-2-1, a z-axis motion platform 4-2-2, a y-axis guide rail slider module 4-2-3, a y-axis motion platform 4-2-4, an x-axis guide rail slider module 4-2-5, a vertical actuator 4-2-6, a horizontal actuator 4-2-7, a coupling mechanism 5, a vibration sensor 6, a measurement and control system 7, and a drive system 8. The relationships between these components are as follows: the frame 1 is connected to the load tray 2 via the horizontal stiffness mechanism 3-1, the vertical stiffness mechanism 3-2, and the coupling mechanism 5; the frame 1 is connected to the load tray 2 via the magnetic spring 4-1; the frame 1 is also connected to... The z-axis guide rail slider module 4-2-1, z-axis motion platform 4-2-2, y-axis guide rail slider module 4-2-3, y-axis motion platform 4-2-4, and x-axis guide rail slider module 4-2-5 are connected to the load tray 2. The frame 1 is connected to the z-axis motion platform 4-2-2 via a vertical actuator 4-2-6. The z-axis motion platform 4-2-2 is connected to the y-axis motion platform 4-2-4 via a set of horizontal actuators 4-2-7. The y-axis motion platform 4-2-4 is connected to the load tray 2 via another set of horizontal actuators 4-2-7. The vibration sensor 6 is connected to the load tray 2 by mechanical fastening. The vibration sensor 6 is connected to the measurement and control system 7 via a cable. The measurement and control system 7 is connected to the drive system 8 via a cable. The drive system 8 is connected to the vertical actuator 4-2-6 and the horizontal actuator 4-2-7 via cables.

[0027] The frame 1 is fixed to the ground and is at a certain height above the ground. Under the constraint of the actuation and guidance mechanism 4-2, the load tray 2 has three degrees of freedom of movement relative to the frame 1 in the x, y and z directions.

[0028] The load tray 2 is connected to various protected objects, i.e. precision equipment, and transmits their gravity to the coupling mechanism 5. The coupling mechanism 5 transmits gravity to the frame 1 through the vertical stiffness mechanism 3-2 and the horizontal stiffness mechanism 3-1, and the frame 1 transmits gravity to the ground.

[0029] The vertical actuator 4-2-6 drives the z-axis moving platform 4-2-2 along the z-axis, one set of horizontal actuators 4-2-7 drives the y-axis moving platform 4-2-4 along the y-axis, and another set of horizontal actuators 4-2-7 drives the load tray 2 along the x-axis.

[0030] Under the constraint of the actuation and guiding mechanism 4-2, the magnetic interaction inside the magnetic spring 4-1 manifests in three directions: x, y, and z. It exhibits negative stiffness in the z direction and positive stiffness in the x and y directions. The horizontal stiffness mechanism 3-1 exhibits negative stiffness in the x and y directions, while the vertical stiffness mechanism exhibits positive stiffness in the z direction. Under the combined action of the multi-directional stiffness component 3 and the magnetic spring 4-1, the stiffness between the load tray 2 and the frame 1 is positive in the x, y, and z directions, providing passive vibration isolation capability.

[0031] The negative stiffness of the horizontal stiffness mechanism 3-1 in the x and y directions is between 0.4 and 0.7 times the positive stiffness of the magnetic spring 4-1 in the corresponding directions; the negative stiffness of the magnetic spring 4-1 in the z direction is between 0.4 and 0.7 times the positive stiffness of the vertical stiffness mechanism 3-2 in that direction.

[0032] The coupling mechanism 5 has multiple rotational degrees of freedom, allowing the load tray 2 to rotate freely within a small range relative to the vertical stiffness mechanism 3-2 without restriction. Under the action of the coupling mechanism 5, the movement of the multi-directional stiffness component 3 and the magnetic spring and actuator component 4 do not conflict and their functions do not interfere with each other.

[0033] The original vibration signal measured by the vibration sensor 6 is converted into a vibration control signal by the measurement and control system 7. The vibration control signal is then converted into a drive signal for the vertical actuator 4-2-6 and the horizontal actuator 4-2-7 by the drive system 8, which actively suppresses the vibration of the load tray 2 and the protected object.

[0034] The negative stiffness of the horizontal stiffness mechanism 3-1 in the x and y directions assists the vibration suppression function of the horizontal actuator 4-2-7; the negative stiffness of the magnetic spring 4-1 in the z direction assists the vibration suppression function of the vertical actuator 4-2-6.

[0035] Preferably, a horizontal stiffening mechanism 3-1, a vertical stiffening mechanism 3-2, and a coupling mechanism 5 are sequentially connected from the frame 1 to the load tray 2, such as... Figure 1 As shown.

[0036] Preferably, the horizontal stiffness mechanism 3-2 is a tie rod connected at both ends by fisheye spherical bearings, and the vertical stiffness mechanism 3-1 is a double-chamber air spring, such as... Figure 2 As shown.

[0037] Preferably, three horizontal stiffening mechanisms 3-1 are used, evenly distributed around the circumference, such as... Figure 2 As shown.

[0038] Preferably, the coupling mechanism 5 adopts a two-degree-of-freedom rigid hinge with a horizontally orthogonal rotating axis, such as... Figure 2 As shown.

[0039] Preferably, the actuation and guiding mechanism 4-2 sequentially realizes the z-axis movement, y-axis movement, and x-axis movement of each guide rail slider module from the frame 1 to the load tray 2, such as... Figure 2 As shown.

[0040] Preferably, the z-guide slider module 4-2-1 is composed of a linear guide bar and a ball bearing; the y-guide slider module 4-2-3 and the x-guide slider module 4-2-5 are cross roller linear guide slider modules.

[0041] Preferably, four sets of magnetic springs 4-1 with the same nominal stiffness are arranged in a circumferentially distributed manner, such as... Figure 3 As shown.

[0042] Preferably, the magnetic spring 4-1 is made of N52 grade neodymium iron boron permanent magnets in the form of a magnet array.

[0043] Preferably, multiple horizontal actuators 4-2-7 with the same nominal performance are divided into two groups, which are used for active vibration suppression in the x and y directions, respectively. Figure 3 As shown.

[0044] For those skilled in the art, any changes, modifications, substitutions, and variations made to the embodiments based on the teachings of the present invention without departing from the principles and spirit of the invention still fall within the protection scope of the present invention.

Claims

1. A passive vibration isolation device with a passive negative stiffness mechanism, characterized in that: The system comprises a frame 1, a load tray 2, a multi-directional stiffness assembly 3, a horizontal stiffness mechanism 3-1, a vertical stiffness mechanism 3-2, a magnetic spring and actuator assembly 4, a magnetic spring 4-1, an actuation and guiding mechanism 4-2, a Z-axis guide rail slider module 4-2-1, a Z-axis motion platform 4-2-2, a Y-axis guide rail slider module 4-2-3, a Y-axis motion platform 4-2-4, an X-axis guide rail slider module 4-2-5, a vertical actuator 4-2-6, a horizontal actuator 4-2-7, a coupling mechanism 5, a vibration sensor 6, a measurement and control system 7, and a drive system 8. The relationships between these components are as follows: the frame 1 is connected to the load tray 2 via the horizontal stiffness mechanism 3-1, the vertical stiffness mechanism 3-2, and the coupling mechanism 5; the frame 1 is connected to the load tray 2 via the magnetic spring 4-1; and the frame 1 is also connected to the Z-axis guide rail slider. Module 4-2-1, Z-axis motion platform 4-2-2, Y-axis guide rail slider module 4-2-3, Y-axis motion platform 4-2-4, and X-axis guide rail slider module 4-2-5 are connected to load tray 2; frame 1 is connected to Z-axis motion platform 4-2-2 via vertical actuator 4-2-6, Z-axis motion platform 4-2-2 is connected to Y-axis motion platform 4-2-4 via a set of horizontal actuators 4-2-7, and Y-axis motion platform 4-2-4 is connected to load tray 2 via another set of horizontal actuators 4-2-7; vibration sensor 6 is connected to load tray 2 by mechanical fastening, vibration sensor 6 is connected to measurement and control system 7 via cable, measurement and control system 7 is connected to drive system 8 via cable, and drive system 8 is connected to vertical actuator 4-2-6 and horizontal actuator 4-2-7 via cable; The frame 1 is fixed to the ground and is at a certain height above the ground. Under the constraint of the actuation and guiding mechanism 4-2, the load tray 2 has three degrees of freedom of movement relative to the frame 1 in the x, y and z directions. The load tray 2 is connected to various protected objects, i.e. precision equipment, and transmits their gravity to the coupling mechanism 5. The coupling mechanism 5 transmits gravity to the frame 1 through the vertical stiffness mechanism 3-2 and the horizontal stiffness mechanism 3-1, and the frame 1 transmits gravity to the ground. The vertical actuator 4-2-6 drives the z-axis moving platform 4-2-2 along the z-axis, one set of horizontal actuators 4-2-7 drives the y-axis moving platform 4-2-4 along the y-axis, and another set of horizontal actuators 4-2-7 drives the load tray 2 along the x-axis; Under the constraint of the actuation and guiding mechanism 4-2, the magnetic interaction inside the magnetic spring 4-1 manifests in three directions: x, y, and z. It exhibits negative stiffness in the z direction and positive stiffness in the x and y directions. The horizontal stiffness mechanism 3-1 exhibits negative stiffness in the x and y directions, while the vertical stiffness mechanism exhibits positive stiffness in the z direction. Under the combined action of the multi-directional stiffness component 3 and the magnetic spring 4-1, the stiffness between the load tray 2 and the frame 1 is positive in the x, y, and z directions, thus providing passive vibration isolation capability. The negative stiffness of the horizontal stiffness mechanism 3-1 in the x and y directions is between 0.4 and 0.7 times the positive stiffness of the magnetic spring 4-1 in the corresponding directions; the negative stiffness of the magnetic spring 4-1 in the z direction is between 0.4 and 0.7 times the positive stiffness of the vertical stiffness mechanism 3-2 in that direction. The coupling mechanism 5 has multiple rotational degrees of freedom, allowing the load tray 2 to rotate freely within a small range relative to the vertical stiffness mechanism 3-2 without restriction; under the action of the coupling mechanism 5, the movement of the multi-directional stiffness component 3 and the magnetic spring and actuator component 4 do not conflict and their functions do not interfere with each other; The original vibration signal measured by the vibration sensor 6 is converted into a vibration control signal by the measurement and control system 7. The vibration control signal is then converted into a drive signal for the vertical actuator 4-2-6 and the horizontal actuator 4-2-7 by the drive system 8, which actively suppresses the vibration of the load tray 2 and the protected object. The negative stiffness of the horizontal stiffness mechanism 3-1 in the x and y directions assists the vibration suppression function of the horizontal actuator 4-2-7; the negative stiffness of the magnetic spring 4-1 in the z direction assists the vibration suppression function of the vertical actuator 4-2-6.

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