A vibration-damping shaft, an active vibration-damping device, and a vibration-damping method

Abstract

The application discloses a damping shaft, an active damping device and a damping method. The damping shaft comprises a rod end joint bearing, a vibration detection assembly, a controller, a passive damping structure and an actuator, and through the steps of passive damping of a vibration source, active identification of the vibration source and active isolation of the vibration source, higher damping efficiency can be achieved. The damping shaft provided by the application is compact in structure, convenient to install and use, can realize active damping, effectively controls the harm of vibration to products, can select a larger working stroke, and provides a new solution for large-amplitude, wide-frequency-range and mobile scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of damping devices, in particular to a damping shaft, an active damping device and a damping method. BACKGROUND

[0002] With the development of science and technology, the use and transportation of some vibration-sensitive products have strict requirements on vibration, such as electron microscopes, photolithography machines and automatic transportation of some semiconductor materials. At present, semiconductor material transportation is mostly manual trolley transfer or passive damping trolley automatic handling, but neither has the function of active damping, so there is a problem that the quality of workpieces cannot be guaranteed during transportation.

[0003] At present, there are many active vibration isolation products on the market, and the driving methods mainly include piezoelectric actuator form and precision air floatation form, but they are all used in fixed occasions and are not suitable for mobile use scenes. The amplitude is mostly within 1mm, and all are imported products with high procurement cost. SUMMARY

[0004] Technical purpose: In view of the above technical problems, the present application provides a damping shaft, an active damping device and a damping method, which has compact structure, convenient installation and use, can realize active damping, and effectively controls the harm of vibration to products.

[0005] Technical scheme: In order to achieve the above technical purpose, the present application adopts the following technical scheme:

[0006] A damping shaft, characterized in that it comprises a damping shaft body, wherein the damping shaft body comprises:

[0007] A rod end joint bearing for connecting a vibration source and conducting vibration;

[0008] A vibration detection assembly for detecting the attenuated vibration signal and sending it to a controller;

[0009] A controller for determining the size of the displacement actively applied by the actuator according to the vibration signal;

[0010] A passive damping structure for attenuating the vibration transmitted by the rod end joint bearing;

[0011] An actuator for moving according to the control instruction, and the passive damping structure is arranged between the actuator and the rod end joint bearing.

[0012] Preferably, the damping shaft comprises a shell, a rod end spherical bearing, a vibration detection assembly, a controller, a passive damping structure and an actuator, the shell is provided with a left side extension rod, a left side end cover, a left side connecting rod, a right side connecting rod, a right side end cover and a right side extension rod at two axial ends respectively, the rod end spherical bearing comprises two groups of extension rods and ball head seats, the ball head seat comprises a rod part connected with the corresponding connecting rod through the left side end cover or the right side end cover and an arc-shaped groove connected with one end of the corresponding extension rod in a spherical hinge mode, and the other end of the extension rod is used for connecting a vibration source.

[0013] Preferably, the actuator comprises a left side guide block, a compression spring, a voice coil motor, a displacement sensor and a right side guide block, the voice coil motor is installed between the left side guide block and the right side guide block, the compression spring is arranged between the voice coil motor and the left side guide block, and a groove for placing the displacement sensor is formed in the left side guide block.

[0014] The two ends of the left side connecting rod are connected with the rod part of the ball head seat and the left side guide block respectively, and the two ends of the right side connecting rod are connected with the rod part of the ball head seat and the right side end cover respectively.

[0015] Preferably, the passive damping structure mainly comprises damping rubber arranged between the right side guide block and the right side end cover.

[0016] Preferably, the vibration detection assembly comprises an acceleration sensor installed in the groove.

[0017] An active damping device, characterized in that: comprising parallel arranged upper platform and lower platform, the upper platform and the lower platform are provided with one or more than one damping shaft.

[0018] A damping method for the active damping device, characterized in that, comprising steps of:

[0019] The rod end spherical bearing is connected with a vibration source, and the vibration is conducted to the passive damping structure via the rod end spherical bearing;

[0020] The passive damping structure attenuates the received vibration, and the attenuated vibration is transmitted to the vibration detection assembly;

[0021] The vibration detection assembly collects vibration signals, including the size and direction of the vibration, and sends them to the controller;

[0022] The controller determines the size of the displacement actively applied by the actuator according to the vibration signal, issues a corresponding control instruction, and the actuator actively applies displacement according to the control instruction.

[0023] Preferably, the actuator comprises a compression spring, a voice coil motor and a displacement sensor, and the displacement actively applied by the actuator according to the control instruction is determined by the following method:

[0024] F2>k*Δy

[0025] The magnitude of Δy is equal to the displacement actively applied by the actuator according to the control command. The direction of the vibration source is opposite. F2 is the driving force of the voice coil motor, and k is the elastic coefficient of the compression spring.

[0026] The compression spring satisfies:

[0027] k*Δx=F1

[0028] F1 is the axial load of a single drive shaft, and Δx is the initial deformation of the compression spring.

[0029] Beneficial effects: Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0030] The vibration damping shaft of this invention is particularly suitable for mobile trolley equipment to isolate vibrations from ground movement. It can use a voice coil motor as the actuator, with a maximum operating frequency of 1000Hz. At the same time, a larger working stroke can be selected, providing a new solution for use in mobile scenarios with large amplitude and wide frequency range. The provided vibration damping shaft can isolate high-frequency and low-frequency vibrations, and is especially suitable for vibration isolation in large amplitude scenarios. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the exploded structure of the drive shaft proposed in Embodiment 1;

[0032] Figure 2 A schematic diagram of the cross-sectional structure of the drive shaft assembly;

[0033] Figure 3 Schematic diagram of a single active vibration damping shaft platform structure;

[0034] Figure 4 Schematic diagram of a 6-axis active vibration damping platform;

[0035] Figure 5 A schematic diagram showing the included angle between the 6 active damping shafts and the upper platform;

[0036] Wherein: 1-Extending rod; 2-Left end cap; 3-Left connecting rod; 4-Left guide block; 5-Compression spring; 6-Voice coil motor; 7-Right guide block; 8-Displacement sensor; 9-Acceleration sensor; 10-Vibration damping rubber;

[0037] 11-Right side connecting rod; 12-Ball head seat; 13-Right side end cap; 14-Outer shell; 15-Damping shaft body; 16-Upper connecting block. Detailed Implementation

[0038] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] This invention provides a design scheme for a vibration damping shaft, a core component in an active vibration isolation system. This scheme overcomes the shortcomings of similar products on the market, such as small amplitude, and enables vibration isolation during movement. The active vibration damping shaft of this invention comprises three steps: passively attenuating the vibration source, actively identifying the vibration source, and actively isolating the vibration source to eliminate vibration. Therefore, as long as the magnitude and frequency of the vibration source are within the design range, the active vibration damping function can be achieved, effectively controlling the harmful effects of vibration.

[0040] Example 1

[0041] This embodiment proposes a reference. Figure 1 The left and right extension rods 1 are connected to the left and right ball joints 12 respectively via ball joints (standard parts are available on the market); the outer shell 14 is connected to the left end cover 2 and the right end cover 13 respectively; the left guide block 4 is connected to the left connecting rod 3 and the outer ring of the voice coil motor 6 respectively; the voice coil motor 6 has a compression spring 5 inside, which is used to balance the load and reduce the driving force of the motor; the right guide block 7 is connected to the inner ring of the voice coil motor 6, and the displacement sensor 8 and the acceleration sensor 9 are installed on the right guide block 9; the right connecting rod 11 is connected to the right end cover 13, and the right end cover 13 has a through hole (wire hole); the outer diameter of the left guide block 4 and the right guide block 7 are respectively clearance-fitted with the inner diameter of the outer shell 14, which plays a sliding and guiding role; the vibration damping rubber 10 is installed between the right guide block 7 and the right end cover 13, which can attenuate the amplitude and instantaneous acceleration of the vibration source.

[0042] See Figure 2 In the actuator, the stroke of the voice coil motor can be selected according to the actual working conditions; the displacement sensor 8 is used to provide real-time feedback on the extended position of the voice coil motor, preventing cumulative errors from causing deviations in the movement position of the voice coil motor; to minimize the driving force of the voice coil motor, the spring force of the compression spring should just balance the load when the voice coil motor is in the initial position (neutral position); see reference Figure 4 , Figure 5 Structural design spring parameters: The total weight of the upper layer is Mg, and the angle between the damping shaft body and the upper platform is α. Therefore, the load on a single drive shaft in a static state is: F1 = Mg / 6cosα (F1 is the axial load of a single drive shaft); because the load is offset by the spring force, the spring must satisfy: k*Δx = F1 = Mg / 6cosα (the spring constant is k, and the initial deformation is Δx); when the vibration source generates vibration, it will cause the right guide block 7 to have an instantaneous motion tendency. To offset the vibration, the voice coil motor needs to compensate for the displacement Δy of the right guide block 7; see reference. Figure 2When the right guide block 7 moves to the left, the voice coil motor 6 needs to retract by the same displacement to keep the left guide block 4 in place. Therefore, the voice coil motor 6 only needs to overcome the spring's elastic force, meaning the driving force of the voice coil motor 6 needs to be greater than the spring's elastic force, i.e., F2>k*Δy (F2 is the driving force of the voice coil motor). The right rod end joint bearing is connected to the vibration source, and the left side is connected to the product being damped. After the vibration is transmitted to the damping shaft, it is first attenuated by the damping rubber. The attenuated vibration is then transmitted to the acceleration detection system by the elastic force generated by the rubber deformation. The detection system collects the magnitude and direction of the vibration and finally sends a signal to the actuator through the controller to actively apply displacement, thereby eliminating the vibration. The solution in this embodiment can achieve high vibration reduction efficiency. Taking into account the certain errors in equipment detection and implementation, the vibration reduction and isolation efficiency can reach over 95%.

[0043] The following is a brief description of the operating logic and process of the active damping shaft under instantaneous stress conditions:

[0044] Step 1: Refer to Figure 2 The vibration damping shaft is connected to the vibration source on the right side and to the vibration isolation material on the left side, with axial vibration excitation provided on the right side;

[0045] Step 2: The vibration excitation passes through the damping rubber 10, and the rubber deforms to attenuate the vibration intensity;

[0046] Step 3: After attenuation, the vibration is transmitted to the right guide block 7, which then tends to move.

[0047] Step 4: Accelerometer 9 detects the motion acceleration of the right guide block 7 and outputs it to the data acquisition unit / vibration detection structure;

[0048] Step 5: The data acquisition unit transmits the signal to the controller, which uses an algorithm to calculate the required input current for the voice coil motor 6.

[0049] Step 6: The voice coil motor 6 receives the command and acts, compensating for the displacement of the right guide block 7, thereby keeping the left guide block 4 and its left side stationary;

[0050] Step 7: The displacement sensor 8 continuously monitors the extension and retraction state of the voice coil motor 6. Through algorithm correction, the voice coil motor 6 is made to always fluctuate around the central origin during the vibration extension and retraction process, preventing the voice coil motor from deviating from the normal position due to accumulated errors.

[0051] Example 2

[0052] This embodiment proposes an active vibration damping device, including an upper platform and a lower platform arranged in parallel, with one or more vibration damping shafts as described in Embodiment 1 located between the upper platform and the lower platform.

[0053] See Figure 3The illustration shows a single active vibration damping shaft application scenario: a single-axis active vibration damping platform, including an active vibration damping shaft body 15, four sets of compression springs, upper and lower platforms, etc. This platform can eliminate vibrations in one direction.

[0054] See Figure 4 The illustration shows a scenario where 6 active vibration damping shafts are used together: a 6-axis active vibration damping platform, including 6 identical active vibration damping shaft bodies 15, upper and lower connecting blocks, upper and lower platforms, etc. This platform can eliminate irregular vibrations of 6 degrees of freedom.

[0055] In this invention, the displacement sensor inside the vibration damping shaft can be replaced with a grating ruler, and the structural usage includes, but is not limited to, " Figure 3 "Single damping shaft type or " Figure 4 "Six-shaft damping configuration."

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vibration damping shaft, characterized in that, The device includes a damping shaft body, comprising: a rod end spherical bearing for connecting a vibration source and transmitting vibration; a vibration detection component for detecting attenuated vibration signals and sending them to a controller; a controller for determining the magnitude of the displacement actively applied by the actuator based on the vibration signals; a passive damping structure for attenuating the vibration transmitted by the rod end spherical bearing; and an actuator for moving according to control commands, wherein the passive damping structure is disposed between the actuator and the rod end spherical bearing. The vibration damping shaft includes a housing, a rod end spherical bearing, a vibration detection component, a controller, a passive vibration damping structure, and an actuator, all housed within the housing. The axial ends of the housing are respectively provided with a left extension rod, a left end cap, a left connecting rod, a right connecting rod, a right end cap, and a right extension rod. The rod end spherical bearing includes two sets of extension rods and a ball head seat. The ball head seat includes a rod portion that passes through the left or right end cap and connects to the corresponding connecting rod, and an arc-shaped groove that connects to one end of the corresponding extension rod using a ball joint. The other end of the extension rod is used to connect to the vibration source. The actuator includes a left guide block, a compression spring, a voice coil motor, a displacement sensor, and a right guide block. The voice coil motor is installed between the left and right guide blocks, and the compression spring is provided between the voice coil motor and the left guide block. A groove for placing the displacement sensor is provided on the left guide block. The two ends of the left connecting rod are respectively connected to the rod part of the ball head seat and the left guide block, and the two ends of the right connecting rod are respectively connected to the rod part of the ball head seat and the right end cap. The passive vibration damping structure mainly includes vibration damping rubber disposed between the right guide block and the right end cap.

2. The vibration damping shaft according to claim 1, characterized in that: The vibration detection assembly includes an acceleration sensor installed within the groove.

3. An active vibration damping device, characterized in that: It includes an upper platform and a lower platform arranged in parallel, and one or more vibration damping shafts as described in any one of claims 1 to 2 are provided between the upper platform and the lower platform.

4. A vibration reduction method for the active vibration damping device of claim 3, characterized in that, The process includes the following steps: the rod end spherical bearing is connected to the vibration source, and the vibration is transmitted to the passive vibration damping structure via the rod end spherical bearing; the passive vibration damping structure attenuates the received vibration, and the attenuated vibration is transmitted to the vibration detection component; the vibration detection component collects the vibration signal, including the magnitude and direction of the vibration, and sends it to the controller; the controller determines the magnitude of the displacement actively applied by the actuator based on the vibration signal, issues a corresponding control command, and the actuator actively applies the displacement according to the control command.

5. The vibration reduction method according to claim 4, characterized in that, The actuator includes a compression spring, a voice coil motor, and a displacement sensor. The displacement actively applied by the actuator according to the control command is determined as follows: F2>k*Δy. The magnitude of Δy is equal to the displacement actively applied by the actuator according to the control command, and the direction of the vibration source is opposite. F2 is the driving force of the voice coil motor, and k is the elastic coefficient of the compression spring. The compression spring satisfies: k*Δx=F1, where F1 is the axial load of a single drive shaft, and Δx is the initial deformation of the compression spring.

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