A permanent magnet electromagnetic composite active and passive vibration isolation system
The permanent magnet electromagnetic composite system addresses the challenges of existing vibration isolation by integrating passive and active components for dynamic stiffness and damping adjustment, achieving reduced stiffness and frequency, enhancing vibration control and equipment reliability.
Patent Information
- Application Number
- CN202210282713.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-03-22
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2042-03-22
AI Technical Summary
Existing vibration isolation systems struggle to meet the demands of large-scale, low stiffness, and flexibility in precision manufacturing, particularly in reducing vibration intensity and maintaining accuracy under varying frequency bands, while existing active systems face challenges in handling large working loads and low-frequency vibrations.
A permanent magnet electromagnetic composite active and passive vibration isolation system that integrates a spring for passive support and a permanent magnet-electromagnet hybrid actuator for active control, allowing dynamic adjustment of stiffness and damping through electromagnetic interactions.
The system effectively reduces overall stiffness and natural frequency, maintaining objects near an initial equilibrium position, enabling robust vibration control across multiple frequency bands and enhancing the reliability and service life of precision equipment.
Smart Images
Figure CN114658784B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of vibration isolation equipment, and in particular relates to a permanent magnet electromagnetic composite active and passive vibration isolation system. Background Art
[0002] The vibration isolation system is the most widely used vibration control technology in vibration control. It is divided into passive vibration isolation, active vibration isolation and active-passive hybrid vibration isolation. Among them, the passive vibration isolation system adds passive elements such as springs, rubber and air springs to the vibration propagation path to reduce the vibration intensity transmitted to the receiving structure. Its structure is simple, easy to implement, reliable, and does not require additional energy. With the development of science and technology, there are higher requirements for the bearing capacity and vibration control accuracy of the structure. At present, large-scale, low stiffness and flexibility are important trends in precision manufacturing. This requires the use of active vibration isolation systems that can withstand large working loads and have excellent vibration isolation performance for low-frequency vibrations. This active vibration isolation system has obvious advantages over passive vibration isolation systems. It can be used in the field of spatial structure vibration isolation of large equipment, and is also suitable for the control of small vibrations. It is widely used in the vibration isolation of precision instruments. Active-passive composite vibration isolation is a new type of vibration isolation technology that applies active control on the basis of passive vibration isolation. It is currently a hot topic in the field of vibration isolation research.
[0003] Vibration runs through the entire life cycle of weapons and equipment, and is a key bottleneck that restricts the accuracy and performance of weapons and equipment. At the same time, vibration will seriously affect the reliability of weapons and equipment and reduce their normal service life. In order to meet the vibration isolation requirements of a certain type of equipment and reduce the damage to the equipment caused by external vibration, it is urgent to design a new type of permanent magnet electromagnetic composite active and passive vibration isolation system to dynamically adjust the stiffness and damping of the system to achieve strong attenuation of external vibration in multiple frequency bands. Summary of the invention
[0004] To solve the above problems, the present invention provides a permanent magnet electromagnetic composite active and passive vibration isolation system, which can effectively reduce the overall stiffness of the system, lower the natural frequency of the system, and actively adjust the stiffness and damping of the system.
[0005] A permanent magnet electromagnetic composite active and passive vibration isolation system provided by the present invention comprises a base plate, a spring fixed on the base plate, a load-bearing platform fixed to the upper part of the spring, an electromagnet fixed on the base plate, a permanent magnet fixed to the top of the electromagnet, and an armature fixed to the bottom surface of the load-bearing platform and opposite to the permanent magnet in the air, wherein the spring is used as a passive vibration isolation device, and provides a static supporting force for the vibration-isolated object by pre-compressing the spring;
[0006] The permanent magnet and the electromagnet together constitute a permanent magnet electromagnetic hybrid actuator, which serves as an active vibration isolation device. The permanent magnet is a negative stiffness element, and the electromagnet is used to actively adjust the stiffness and damping of the entire system by changing the magnitude and direction of voltage and current. Under no-current conditions, there is electromagnetic attraction between the permanent magnet and the armature to keep the vibration-isolated object in an initial equilibrium position.
[0007] Preferably, in the above permanent magnet electromagnetic composite active and passive vibration isolation system, the electromagnet is an E-type electromagnet, and its core pole area range is 7000mm 2 Up to 8000mm 2 .
[0008] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the cross-sectional area of the permanent magnet is the same as the core pole area of the electromagnet.
[0009] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the thickness of the permanent magnet ranges from 9.5 mm to 10.5 mm.
[0010] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the material of the permanent magnet is neodymium iron boron.
[0011] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the material of the electromagnet is a silicon steel disc.
[0012] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the coil of the electromagnet comprises an enameled copper round wire, the number of winding turns ranges from 375 to 400, and the width of the coil winding ranges from 29 mm to 30 mm.
[0013] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the number of the springs is four, and the springs are cylindrical helical springs with equal pitch.
[0014] Preferably, in the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the height range of the spring is 170 mm to 180 mm.
[0015] From the above description, it can be known that the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system provided by the present invention includes a base plate, a spring fixed on the base plate, a load-bearing platform fixed to the upper part of the spring, and also includes an electromagnet fixed on the base plate, a permanent magnet fixed to the top of the electromagnet, and an armature fixed to the bottom surface of the load-bearing platform and opposite to the permanent magnet in the air, wherein the spring is used as a passive vibration isolation device, and a static supporting force is provided to the isolated object by pre-compressing the spring. This spring can be used as a positive stiffness element to provide positive stiffness for the entire system, and provide supporting force for the load-bearing platform and the isolated object on the load-bearing platform through pre-compression of the spring; the permanent magnet and the electromagnet together constitute a permanent magnet electromagnetic hybrid actuator, which serves as an active vibration isolation device. The permanent magnet is used as a negative stiffness element, and the electromagnet is used to change the voltage The magnitude and direction of the current are used to actively adjust the stiffness and damping of the entire system. When there is no current in the electromagnet, there is electromagnetic attraction between the permanent magnet and the armature, which can balance the positive stiffness brought to the system by the spring, so that the vibration-isolated object is in the initial equilibrium position, and the entire load-bearing platform vibrates near the initial equilibrium position, which reduces the overall stiffness of the system and reduces the natural frequency of the system. At the same time, the permanent magnet itself will generate a bias magnetic field. By adding an electromagnet to the bias magnetic field, the magnitude and direction of the current in the electromagnet are changed, thereby changing the strength of the bias magnetic field, and then changing the magnetic force generated by the permanent magnet electromagnetic hybrid actuator. It can be seen that this scheme can not only reduce the stiffness of the system, but also dynamically adjust the equivalent stiffness and damping of the system by adjusting the input current of the electromagnet, thereby realizing active vibration control. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.
[0017] Figure 1 A schematic diagram of an embodiment of a permanent magnet electromagnetic composite active and passive vibration isolation system provided by the present invention. DETAILED DESCRIPTION
[0018] The core of the present invention is to provide a permanent magnet electromagnetic composite active and passive vibration isolation system, which can effectively reduce the overall stiffness of the system, reduce the natural frequency of the system, and actively adjust the stiffness and damping of the system.
[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0020] An implementation example of a permanent magnet electromagnetic composite active and passive vibration isolation system provided by the present invention is as follows: Figure 1 As shown, Figure 1 A schematic diagram of an embodiment of a permanent magnet electromagnetic composite active and passive vibration isolation system provided by the present invention, the system comprises a base plate 1, a spring 2 fixed on the base plate 1, a load-bearing platform 3 fixed to the upper part of the spring 2, an electromagnet 4 fixed on the base plate 1, a permanent magnet 5 fixed to the top of the electromagnet 4, and an armature 6 fixed to the bottom surface of the load-bearing platform 3 and opposite to the permanent magnet 5 in the air, wherein the spring 2 is used as a passive vibration isolation device, and a static supporting force is provided for the vibration-isolated object by pre-compressing the spring 2;
[0021] The permanent magnet 5 and the electromagnet 4 together constitute a permanent magnet electromagnetic hybrid actuator, which serves as an active vibration isolation device. The permanent magnet 5 is a negative stiffness element, and the electromagnet 4 is used to actively adjust the stiffness and damping of the entire system by changing the magnitude and direction of the voltage and current. Under no-current conditions, there is an electromagnetic attraction between the permanent magnet 5 and the armature 6 to keep the object to be isolated in an initial equilibrium position.
[0022] It should be noted that the above system can be placed on a vibration table 7, which is used to provide the system with the required external vibration environment and can dynamically adjust the amplitude, frequency and excitation time of the excitation as needed. The lower end of the vibration table can be fixed to the ground, and the upper end carries the above permanent magnet electromagnetic composite active and passive vibration isolation system. The above spring 2 can be a mechanical spring, which serves as a positive stiffness element to provide positive stiffness for the entire system. Secondly, the spring pre-compression provides support force for the load-bearing platform and the object to be isolated. At the same time, under the condition of no external input, that is, the electromagnet has no input current, the suction force between the permanent magnet and the armature can also be balanced, so that the entire load-bearing platform vibrates near the initial equilibrium position. The permanent magnet electromagnetic hybrid actuator is the core equipment of the permanent magnet electromagnetic active and passive composite vibration isolation system, which can be but is not limited to using Figure 1The E-type electromagnet in the embodiment of the present invention is a permanent magnet installed on the top of the E-type electromagnet. In addition, the armature can be but not limited to being connected to the bottom of the load-bearing platform by bolts, and the lower end of the armature can be but not limited to being 10 mm away from the upper end of the permanent magnet. The permanent magnet is used as a negative stiffness element. According to the negative stiffness theory, even if the electromagnet input current is 0, the permanent magnet can still balance the positive stiffness of the system brought by the spring passive vibration isolation device, thereby reducing the overall stiffness of the system. At the same time, the permanent magnet itself will generate a bias magnetic field. An electromagnet is added to the bias magnetic field. By changing the magnitude and direction of the current in the electromagnet, the strength of the bias magnetic field is changed, and the magnetic force generated by the permanent magnet electromagnetic hybrid actuator is changed. Such an actuator can not only reduce the stiffness of the system through the permanent magnet, but also can further dynamically adjust the equivalent stiffness and damping of the entire system by adjusting the electromagnet input current, thereby providing the possibility for active vibration control of the system.
[0023] It can be known from the above description that in the embodiment of the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system provided by the present invention, it includes a base plate, a spring fixed on the base plate, a load-bearing platform fixed to the upper part of the spring, and also includes an electromagnet fixed on the base plate, a permanent magnet fixed to the top of the electromagnet, and an armature fixed to the bottom surface of the load-bearing platform and opposite to the permanent magnet in the air, wherein the spring is used as a passive vibration isolation device, and provides static supporting force for the isolated object by pre-compressing the spring. This spring can be used as a positive stiffness element to provide positive stiffness for the entire system, and provide supporting force for the load-bearing platform and the isolated object on the load-bearing platform through pre-compression of the spring; the permanent magnet and the electromagnet together constitute a permanent magnet electromagnetic hybrid actuator, which serves as an active vibration isolation device. The permanent magnet is used as a negative stiffness element, and the electromagnet is used to change The magnitude and direction of the voltage and current are used to actively adjust the stiffness and damping of the entire system. When there is no current in the electromagnet, there is electromagnetic attraction between the permanent magnet and the armature, which can balance the positive stiffness brought to the system by the spring, so that the vibration-isolated object is in the initial equilibrium position, and the entire load-bearing platform vibrates near the initial equilibrium position, which reduces the overall stiffness of the system and reduces the natural frequency of the system. At the same time, the permanent magnet itself will generate a bias magnetic field. By adding an electromagnet to the bias magnetic field, the magnitude and direction of the current in the electromagnet are changed, thereby changing the strength of the bias magnetic field, and then changing the magnetic force generated by the permanent magnet electromagnetic hybrid actuator. It can be seen that this scheme can not only reduce the stiffness of the system, but also dynamically adjust the equivalent stiffness and damping of the system by adjusting the input current of the electromagnet, thereby realizing active vibration control.
[0024] In a specific embodiment of the permanent magnet electromagnetic composite active and passive vibration isolation system, the electromagnet can preferably be an E-type electromagnet, and the core pole area range can be but is not limited to 7000mm 2 Up to 8000mm 2Further, the material of the electromagnet is preferably a silicon steel disc, and the coil of the electromagnet may include an enameled copper round wire, the number of turns of the winding ranges from 375 to 400, and the width of the coil winding ranges from 29 mm to 30 mm.
[0025] It should be noted that the electromagnet is the active control module of the permanent magnet electromagnetic hybrid actuator. This module mainly controls the current input to the electromagnet by controlling the control voltage at both ends of the electromagnet. The different currents passing through the electromagnet will cause the permanent magnet electromagnetic hybrid actuator to generate different magnetic field strengths, ultimately achieving the purpose of adjusting the suction force. According to the specific use of the electromagnet, the design of the electromagnet mainly includes the selection of E-type electromagnet core and wire materials and spatial dimensions. The E-type electromagnet has a good spatial structure and the height requirements meet the requirements. It is suitable for use in this system. Considering that the system will face continuous vibration and electromagnet heat generation problems during work, the electromagnet core and armature are both in the form of silicon steel discs. Moreover, in order to reduce the heat generated by the electromagnet during work, the coil of the electromagnet preferably uses enameled copper round wire with low resistance, and the insulation level of the electromagnet after processing must meet Class F.
[0026] It should also be noted that the suction force of the E-type electromagnet is proportional to the core pole area. The larger the core pole area, the stronger the suction force of the E-type electromagnet. However, it is also limited by the installation space. Therefore, the core pole area range is preferably 7000mm 2 Up to 8000mm 2 To meet the requirements of both suction and space, for the convenience of coil winding, the middle core pole surface can be square, and the left and right core pole surfaces can be the same rectangle. At the same time, in order to ensure that the leakage magnetic phenomenon of the designed electromagnet is reduced as much as possible, the size of the armature can be designed to correspond to the size of the electromagnet pole.
[0027] In another specific embodiment of the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the cross-sectional area of the permanent magnet can be the same as the core pole area of the electromagnet, and the thickness range of the permanent magnet can be preferably 9.5mm to 10.5mm, and its material can be preferably neodymium iron boron, which has high energy density, extremely large coercive force and magnetic energy product, and low cost. At room temperature, the residual magnetic induction intensity of neodymium iron boron can reach up to 1.4756T, and the coercive force can reach 955KA / m. Compared with other permanent magnets, it has higher stability. Of course, other materials can also be selected according to actual needs, which is not limited here. It should also be noted that the thickness of the permanent magnet is further preferably 10mm, and its stiffness better meets the requirements and can provide sufficient force.
[0028] In the above-mentioned permanent magnet electromagnetic composite active and passive vibration isolation system, the number of springs can be preferably four, and the springs are selected from equi-pitch cylindrical helical springs, whose stiffness is approximately constant, and the characteristic line is closer to a straight line, simple structure, easy to process and manufacture, which can simplify the design of the vibration isolation system, and at the same time can achieve a good passive vibration isolation effect, meeting the design requirements of the system. At the same time, in order to ensure the stability of the spring structure, the spring does not have horizontal lateral bending, and the spring can also be directly sleeved on the linear bearing guide rod to limit the horizontal degree of freedom of the spring, so that the spring can only be compressed and extended in the vertical direction, ensuring horizontal stability. The selected linear bearing guide rod diameter can be 20mm. On this basis, in order to ensure that there will be no large sliding friction and horizontal lateral bending between the spring and the guide rod, the selection of the inner diameter of the spring must be greater than 20mm, and a certain margin must be left to ensure that there will be no large sliding friction. Of course, this is only a preferred solution, and other types of springs can also be selected according to actual needs, which is not limited here. Furthermore, the height range of the above-mentioned spring can preferably be 170mm to 180mm, which is the free length of the spring. This better meets the deformation requirement. During the assembly process, there may be excess, and gaskets can be used for filling and adjustment.
[0029] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A permanent magnet electromagnetic composite active and passive vibration isolation system, characterized in that: It includes a bottom plate, a spring fixed on the bottom plate, a load-bearing platform fixed to the upper part of the spring, an electromagnet fixed on the bottom plate, a permanent magnet fixed to the top of the electromagnet, and an armature fixed to the bottom surface of the load-bearing platform and opposite to the permanent magnet in the air, wherein the spring is used as a passive vibration isolation device, and provides static support force for the vibration-isolated object by pre-compressing the spring; The permanent magnet and the electromagnet together constitute a permanent magnet electromagnetic hybrid actuator, which serves as an active vibration isolation device. The permanent magnet is a negative stiffness element, and the electromagnet is used to actively adjust the stiffness and damping of the entire system by changing the magnitude and direction of voltage and current. Under no-current conditions, there is electromagnetic attraction between the permanent magnet and the armature to keep the vibration-isolated object in an initial equilibrium position; the thickness of the permanent magnet ranges from 9.5 mm to 10.5 mm; the material of the permanent magnet is neodymium iron boron; the cross-sectional area of the permanent magnet is the same as the core pole area of the electromagnet.