Intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator

Abstract

The invention discloses an intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator which comprises a base frame and an active electromagnetic unit arranged on the base frame and is used for outputting adjustable electromagnetic negative stiffness and controllable electromagnetic force and providing stable thrust for vibration isolation through the controllable electromagnetic force. The device is applied to the technical field of precise vibration isolation, the active electromagnetic unit is used for outputting large-stroke linear adjustable electromagnetic negative stiffness and controllable electromagnetic force, and the adjustable electromagnetic negative stiffness and positive stiffness mechanical springs are combined to reduce the dynamic stiffness, so that the vibration isolation bandwidth is expanded, the inherent frequency of the system is reduced to isolate the vibration of the base, and the vibration isolation efficiency is improved. The stable controllable electromagnetic thrust is used for achieving flexible active vibration control, the integrated design of high-static low-dynamic-stiffness vibration isolation and active intelligent vibration isolation is achieved, and therefore the multi-source vibration suppression problem of the high-static low-dynamic-stiffness vibration isolator is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of precision vibration isolation, and specifically to an intelligent adjustable high-static low-dynamic stiffness integrated active vibration isolator, which can achieve vibration isolation performance of high-static low-dynamic stiffness and active vibration isolation function simultaneously under a compact structure. Background Art

[0002] The demand for vibration isolation in ultra-precision machining and measuring equipment is increasing day by day. At present, introducing the parallel connection of negative stiffness and positive stiffness to achieve high-static low-dynamic stiffness is an efficient and reliable measure to broaden the vibration isolation frequency band. The high-static low-dynamic stiffness vibration isolator can solve the contradiction between load bearing and vibration isolation to a certain extent.

[0003] However, since the reduction of the stiffness of the vibration isolator will inevitably lead to the decline of the performance of directly suppressing the load disturbance, the existing solutions generally add an actuator additionally on the basis of the high-static low-dynamic stiffness vibration isolator for active vibration isolation, which will inevitably increase the overall size and cost of the vibration isolator. Summary of the Invention

[0004] Aiming at the deficiencies in the above-mentioned prior art, the present invention provides an intelligent adjustable high-static low-dynamic stiffness integrated active vibration isolator, which can simultaneously achieve large-stroke linearly adjustable electromagnetic negative stiffness and stable electromagnetic thrust output, and has an integrated compact structure. The electromagnetic negative stiffness is used to reduce the natural frequency of the system to isolate the vibration of the base, and the stable electromagnetic thrust is used to achieve flexible active vibration control, providing an effective and feasible solution for multi-source vibration suppression of precision loads.

[0005] To achieve the above object, the present invention provides an intelligent adjustable high-static low-dynamic stiffness integrated active vibration isolator, including a base frame and an active electromagnetic unit arranged on the base frame, which is used to output adjustable electromagnetic negative stiffness and controllable electromagnetic force, and use the controllable electromagnetic force to provide a stable thrust for vibration isolation; The active electromagnetic unit includes a composite magnet array and a multi-functional electromagnetic coil group; The composite magnet array includes an inner ring permanent magnet array and an outer ring permanent magnet array coaxially and spacedly arranged on the inner ring permanent magnet array. There are axially adjacent first air-gap magnetic fluxes and second air-gap magnetic fluxes in the air gap between the inner ring permanent magnet array and the outer ring permanent magnet array. The magnetic flux densities of the first air-gap magnetic flux and the second air-gap magnetic flux are equal in magnitude and opposite in direction; The multi-functional electromagnetic coil group includes an inner-layer active controllable electromagnetic force coil and an outer-layer active adjustable electromagnetic negative stiffness coil. The inner-layer active controllable electromagnetic force coil includes a forward winding coil and a reverse winding coil with equal length and number of turns, and the outer-layer active adjustable electromagnetic negative stiffness coil is a single-direction winding coil; The first air-gap magnetic flux passes through one of the forward winding coil and the reverse winding coil, and the second air-gap magnetic flux passes through the other of the forward winding coil and the reverse winding coil. Both the first air-gap magnetic flux and the second air-gap magnetic flux pass through the outer-layer actively adjustable electromagnetic negative stiffness coil.

[0006] In one embodiment, the multi-functional electromagnetic coil group further includes a coil skeleton; The inner-layer actively controllable electromagnetic force coil is fixed on the coil skeleton by resin infusion, and the outer-layer actively adjustable electromagnetic negative stiffness coil is fixed on the inner-layer actively controllable electromagnetic force coil by resin infusion.

[0007] In one embodiment, the positive stiffness mechanical spring of the intelligent adjustable high-static low-dynamic stiffness integrated active vibration isolator is used to bear the load and is connected in parallel with the adjustable electromagnetic negative stiffness to reduce the dynamic stiffness, thereby realizing the expansion of the vibration isolation bandwidth.

[0008] In one embodiment, the base frame includes a vibration isolator base and a support rod provided on the vibration isolator base; The positive stiffness mechanical spring is fixedly provided on the support rod, the active electromagnetic unit is provided on the vibration isolator base and is located below the positive stiffness mechanical spring, and the top end of the coil skeleton is fixedly connected to the positive stiffness mechanical spring.

[0009] In one embodiment, the intelligent adjustable high-static low-dynamic stiffness integrated active vibration isolator further includes a load connection mechanism; The load connection mechanism includes a optical axis guide rod, a guide bearing and a bearing mounting bracket. The bearing mounting bracket is provided on the support rod and is located above the positive stiffness mechanical spring, and the guide bearing is provided on the bearing mounting bracket; One end of the optical axis guide rod is connected to the positive stiffness mechanical spring, and the other end passes through the guide bearing and is connected to an external load.

[0010] In one embodiment, the inner-ring permanent magnet array includes a first end axially magnetized cylindrical permanent magnet, a middle axially magnetized cylindrical permanent magnet, a second end axially magnetized cylindrical permanent magnet, a first radially magnetized annular permanent magnet and a second radially magnetized annular permanent magnet; The first end axially magnetized cylindrical permanent magnet, the middle axially magnetized cylindrical permanent magnet, and the second end axially magnetized cylindrical permanent magnet are spaced apart from top to bottom in sequence. The first radially magnetized annular permanent magnet is located between the first end axially magnetized cylindrical permanent magnet and the middle axially magnetized cylindrical permanent magnet. The second radially magnetized annular permanent magnet is located between the middle axially magnetized cylindrical permanent magnet and the second end axially magnetized cylindrical permanent magnet. Among them, the magnetization directions of the first end axially magnetized cylindrical permanent magnet and the second end axially magnetized cylindrical permanent magnet are both opposite to that of the middle axially magnetized cylindrical permanent magnet, and the magnetization directions of the first radially magnetized annular permanent magnet and the second radially magnetized annular permanent magnet are opposite; The outer ring permanent magnet array includes a first end axially magnetized annular permanent magnet, a middle axially magnetized annular permanent magnet, a second end axially magnetized annular permanent magnet, a third radially magnetized annular permanent magnet, and a fourth radially magnetized annular permanent magnet; The first end axially magnetized annular permanent magnet has the same thickness as the first end axially magnetized cylindrical permanent magnet and the magnetization directions are opposite. The first end axially magnetized annular permanent magnet is coaxially and spacedly sleeved on the first end axially magnetized cylindrical permanent magnet and the two ends are flush; The middle axially magnetized annular permanent magnet has the same thickness as the middle axially magnetized cylindrical permanent magnet and the magnetization directions are opposite. The middle axially magnetized annular permanent magnet is coaxially and spacedly sleeved on the middle axially magnetized cylindrical permanent magnet and the two ends are flush; The second end axially magnetized annular permanent magnet has the same thickness as the second end axially magnetized cylindrical permanent magnet and the magnetization directions are opposite. The second end axially magnetized annular permanent magnet is coaxially and spacedly sleeved on the second end axially magnetized cylindrical permanent magnet and the two ends are flush; The third radially magnetized annular permanent magnet has the same thickness as the first radially magnetized annular permanent magnet and the magnetization directions are the same. The third radially magnetized annular permanent magnet is coaxially and spacedly sleeved on the first radially magnetized annular permanent magnet and the two ends are flush. The first air-gap magnetic flux is located between the third radially magnetized annular permanent magnet and the first radially magnetized annular permanent magnet; The fourth radially magnetized annular permanent magnet has the same thickness as the second radially magnetized annular permanent magnet and the magnetization directions are the same. The fourth radially magnetized annular permanent magnet is coaxially and spacedly sleeved on the second radially magnetized annular permanent magnet and the two ends are flush. The second air-gap magnetic flux is located between the fourth radially magnetized annular permanent magnet and the second radially magnetized annular permanent magnet.

[0011] In one embodiment, the top of the first end axially magnetized cylindrical permanent magnet is covered with a first cylindrical magnetic yoke, and the top of the first end axially magnetized annular permanent magnet is covered with a first annular magnetic yoke; A second cylindrical yoke is embedded in the annular opening of the first radially magnetized annular permanent magnet, and a second annular yoke is sleeved on the outer ring wall of the third radially magnetized annular permanent magnet; A third cylindrical yoke is embedded in the annular opening of the second radially magnetized annular permanent magnet, and a third annular yoke is sleeved on the outer ring wall of the fourth radially magnetized annular permanent magnet; A fourth cylindrical yoke is provided at the bottom of the second axially magnetized cylindrical permanent magnet, and a fourth annular yoke covers the top of the second axially magnetized annular permanent magnet.

[0012] In one embodiment, the permanent magnets in the inner ring permanent magnet array and the outer ring permanent magnet array are made of alnico permanent magnet materials, neodymium iron boron permanent magnet materials, iron chromium cobalt permanent magnet materials, ferrite permanent magnet materials, rare earth permanent magnet materials or composite permanent magnet materials, etc.

[0013] In one embodiment, the first cylindrical yoke, the first annular yoke, the second cylindrical yoke, the second annular yoke, the third cylindrical yoke, the third annular yoke, the fourth cylindrical yoke, and the fourth annular yoke are made of soft magnetic materials.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention utilizes the active electromagnetic unit to output a large-stroke linearly adjustable electromagnetic negative stiffness and a controllable electromagnetic force, wherein the adjustable electromagnetic negative stiffness is connected in parallel with the positive stiffness mechanical spring to reduce the dynamic stiffness, thereby realizing the expansion of the vibration isolation bandwidth, reducing the natural frequency of the system to isolate the vibration of the base, and the stable controllable electromagnetic thrust is used to realize flexible active vibration control, realizing the integrated design of high-static low-dynamic stiffness vibration isolation and active intelligent vibration isolation, thereby improving the multi-source vibration suppression problem of high-static low-dynamic stiffness vibration isolators, and having a compact structure, low cost, and being convenient for engineering practical applications. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0016] Figure 1 It is a schematic cross-sectional structure diagram of an intelligent adjustable high-static low-dynamic stiffness integrated active vibration isolator in an embodiment of the present invention; Figure 2 It is a schematic structure diagram of a composite magnet array and a multi-functional electromagnetic coil in an embodiment of the present invention; Figure 3It is the graph of the air-gap flux density characteristic of the vibration isolator in the embodiment of the present invention; Figure 4 It is the graph of the controllable electromagnetic force characteristic of the vibration isolator within the stroke range in the embodiment of the present invention; Figure 5 It is the graph of the force characteristic of the adjustable electromagnetic negative stiffness of the vibration isolator within the stroke range in the embodiment of the present invention.

[0017] Reference numerals in the drawings: 1 - load, 2 - optical axis guide rod, 3 - guide bearing, 4 - bearing mounting bracket, 5 - positive stiffness mechanical spring, 6 - multi-functional electromagnetic coil group, 601 - coil skeleton, 602 - inner layer actively controllable electromagnetic force coil, 603 - outer layer actively adjustable electromagnetic negative stiffness coil, 7 - composite magnet array, 701 - first cylindrical magnetic yoke, 702 - first circular magnetic yoke, 703 - first end axially magnetized ring permanent magnet, 704 - third radially magnetized ring permanent magnet, 705 - second circular magnetic yoke, 706 - intermediate axially magnetized ring permanent magnet, 707 - fourth radially magnetized ring permanent magnet, 708 - third circular magnetic yoke, 709 - fourth cylindrical magnetic yoke, 710 - fourth circular magnetic yoke, 711 - first end axially magnetized cylindrical permanent magnet, 712 - second cylindrical magnetic yoke, 713 - first radially magnetized ring permanent magnet, 714 - intermediate axially magnetized cylindrical permanent magnet, 715 - third cylindrical magnetic yoke, 716 - second radially magnetized ring permanent magnet, 717 - second end axially magnetized cylindrical permanent magnet, 718 - second end axially magnetized ring permanent magnet, 719 - non-magnetic base, 8 - vibration isolator base, 9 - support rod.

[0018] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0020] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0021] In addition, in the present invention, descriptions such as "first", "second", etc. are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0022] In the present invention, unless otherwise clearly specified and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a physical connection or a wireless communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] As Figure 1 、 Figure 2 As shown, a kind of intelligent adjustable high-static and low-dynamic stiffness integrated active vibration isolator disclosed in this embodiment mainly includes a base frame, an active electromagnetic unit arranged on the base frame, a positive stiffness mechanical spring 5 and a load connection mechanism. Among them, the base frame includes an isolator base 8 and a support rod 9 arranged on the isolator base 8. The support rod 9 can be selected as a screw rod, and the number of them is two and they are threadedly connected to the isolator base 8 in parallel at intervals.

[0025] The active electromagnetic unit is arranged on the vibration isolator base 8 and is used to output adjustable electromagnetic negative stiffness and controllable electromagnetic force. The controllable electromagnetic force generated by the active electromagnetic unit is used to provide a stable thrust for vibration isolation, realizing flexible active vibration control. The positive stiffness mechanical spring 5 is fixedly arranged on the support rod 9 by means of welding, bolt fixing, etc., and the positive stiffness mechanical spring 5 is located directly above the active electromagnetic unit. The positive stiffness mechanical spring 5 is used for bearing and is connected in parallel with the adjustable electromagnetic negative stiffness to reduce the dynamic stiffness, thereby realizing the expansion of the vibration isolation bandwidth. The load connection mechanism is connected to the positive stiffness mechanical spring 5 and is mainly used to constrain the movement direction of the load 1. Specifically, the load connection mechanism includes an optical axis guide rod 2, a guide bearing 3 and a bearing mounting bracket 4. The bearing mounting bracket 4 is fixedly arranged on the support rod 9 by means of welding, bolt fixing, etc. and is located above the positive stiffness mechanical spring 5. The guide bearing 3 is fixedly arranged on the bearing mounting bracket 4. One end of the optical axis guide rod 2 is fixedly connected to the center of the positive stiffness mechanical spring 5 by means of bolt connection, welding, etc., and the other end passes through the guide bearing 3 and is connected to the external load 1.

[0026] In this embodiment, the active electromagnetic unit includes a composite magnet array 7 and a multi-functional electromagnetic coil group 6.

[0027] The composite magnet array 7 includes a non-magnetic base 719 and an inner ring permanent magnet array and an outer ring permanent magnet array arranged on the non-magnetic base 719. The non-magnetic base 719 is fixedly connected to the vibration isolator base 8 by screws. The outer ring permanent magnet array is coaxially and spacedly sleeved on the inner ring permanent magnet array, so that an annular cylindrical air gap is formed between the outer wall of the inner ring permanent magnet array and the inner wall of the outer ring permanent magnet array. At the same time, under the action of the inner ring permanent magnet array and the outer ring permanent magnet array, a first air gap magnetic flux and a second air gap magnetic flux adjacent along the axis are formed in the air gap, and the magnetic flux densities of the first air gap magnetic flux and the second air gap magnetic flux are equal in magnitude and opposite in direction.

[0028] The inner ring permanent magnet array includes a first end axially magnetized cylindrical permanent magnet 711, a middle axially magnetized cylindrical permanent magnet 714, a second end axially magnetized cylindrical permanent magnet 717, a first radially magnetized annular permanent magnet 713 and a second radially magnetized annular permanent magnet 716. The first end axially magnetized cylindrical permanent magnet 711, the middle axially magnetized cylindrical permanent magnet 714, and the second end axially magnetized cylindrical permanent magnet 717 are of the same cylindrical configuration with the same diameter. The first radially magnetized annular permanent magnet 713 and the second radially magnetized annular permanent magnet 716 are of the same annular configuration with the same inner and outer diameters, and the outer diameters of the first radially magnetized annular permanent magnet 713 and the second radially magnetized annular permanent magnet 716 are equal to the diameter of the first end axially magnetized cylindrical permanent magnet 711, the middle axially magnetized cylindrical permanent magnet 714, and the second end axially magnetized cylindrical permanent magnet 717.

[0029] The first end axially magnetized cylindrical permanent magnet 711, the middle axially magnetized cylindrical permanent magnet 714, and the second end axially magnetized cylindrical permanent magnet 717 are coaxially and spaced apart from top to bottom in sequence. The first radially magnetized annular permanent magnet 713 is coaxially located between the first end axially magnetized cylindrical permanent magnet 711 and the middle axially magnetized cylindrical permanent magnet 714, and the second radially magnetized annular permanent magnet 716 is coaxially located between the middle axially magnetized cylindrical permanent magnet 714 and the second end axially magnetized cylindrical permanent magnet 717. Among them, the magnetization directions of the first end axially magnetized cylindrical permanent magnet 711 and the second end axially magnetized cylindrical permanent magnet 717 are both opposite to that of the middle axially magnetized cylindrical permanent magnet 714, and the magnetization directions of the first radially magnetized annular permanent magnet 713 and the second radially magnetized annular permanent magnet 716 are opposite.

[0030] The outer ring permanent magnet array includes a first end axially magnetized annular permanent magnet 703, a middle axially magnetized annular permanent magnet 706, a second end axially magnetized annular permanent magnet 718, a third radially magnetized annular permanent magnet 704, and a fourth radially magnetized annular permanent magnet 707 in an annular configuration. Among them, the inner diameters of the third radially magnetized annular permanent magnet 704 and the fourth radially magnetized annular permanent magnet 707 are smaller than the inner diameters of the first end axially magnetized annular permanent magnet 703, the middle axially magnetized annular permanent magnet 706, and the second end axially magnetized annular permanent magnet 718.

[0031] The first-end axially magnetized annular permanent magnet 703 and the first-end axially magnetized cylindrical permanent magnet 711 have the same thickness and opposite magnetization directions. At the same time, the first-end axially magnetized annular permanent magnet 703 is coaxially and spacedly sleeved on the first-end axially magnetized cylindrical permanent magnet 711 and their two ends are flush. The middle axially magnetized annular permanent magnet 706 and the middle axially magnetized cylindrical permanent magnet 714 have the same thickness and opposite magnetization directions. The middle axially magnetized annular permanent magnet 706 is coaxially and spacedly sleeved on the middle axially magnetized cylindrical permanent magnet 714 and their two ends are flush. The second-end axially magnetized annular permanent magnet 718 and the second-end axially magnetized cylindrical permanent magnet 717 have the same thickness and opposite magnetization directions. The second-end axially magnetized annular permanent magnet 718 is coaxially and spacedly sleeved on the second-end axially magnetized cylindrical permanent magnet 717 and their two ends are flush. The third radially magnetized annular permanent magnet 704 and the first radially magnetized annular permanent magnet 713 have the same thickness and the same magnetization direction. The third radially magnetized annular permanent magnet 704 is coaxially and spacedly sleeved on the first radially magnetized annular permanent magnet 713 and their two ends are flush. The first air-gap magnetic flux is located between the third radially magnetized annular permanent magnet 704 and the first radially magnetized annular permanent magnet 713. The fourth radially magnetized annular permanent magnet 707 and the second radially magnetized annular permanent magnet 716 have the same thickness and the same magnetization direction. The fourth radially magnetized annular permanent magnet 707 is coaxially and spacedly sleeved on the second radially magnetized annular permanent magnet 716 and their two ends are flush. The second air-gap magnetic flux is located between the fourth radially magnetized annular permanent magnet 707 and the second radially magnetized annular permanent magnet 716.

[0032] As a preferred embodiment, the composite magnet array 7 further includes a first cylindrical yoke 701, a second cylindrical yoke 712, a third cylindrical yoke 715, and a fourth cylindrical yoke 709 in a cylindrical configuration, and a first ring yoke 702, a second ring yoke 705, a third ring yoke 708, and a fourth ring yoke 710 in a ring configuration. Among them, the first cylindrical yoke 701 covers the top of the first-end axially magnetized cylindrical permanent magnet 711, and the first ring yoke 702 covers the top of the first-end axially magnetized ring permanent magnet 703. The second cylindrical yoke 712 is embedded in the ring opening of the first radially magnetized ring permanent magnet 713, and the side wall of the second cylindrical yoke 712 is in contact or clearance fit with the inner ring wall of the first radially magnetized ring permanent magnet 713. The two ends of the second cylindrical yoke 712 are in contact or clearance fit with the first-end axially magnetized ring permanent magnet 703 and the middle axially magnetized ring permanent magnet 706 respectively. The second ring yoke 705 is sleeved on the outer ring wall of the third radially magnetized ring permanent magnet 704, and the inner ring wall of the second ring yoke 705 is in contact or clearance fit with the outer ring wall of the third radially magnetized ring permanent magnet 704. The two ends of the second ring yoke 705 are in contact or clearance fit with the first-end axially magnetized ring permanent magnet 703 and the middle axially magnetized ring permanent magnet 706 respectively. The third cylindrical yoke 715 is embedded in the ring opening of the second radially magnetized ring permanent magnet 716, and the side wall of the third cylindrical yoke 715 is in contact or clearance fit with the inner ring wall of the second radially magnetized ring permanent magnet 716. The two ends of the third cylindrical yoke 715 are in contact or clearance fit with the second-end axially magnetized ring permanent magnet 718 and the middle axially magnetized ring permanent magnet 706 respectively. The third ring yoke 708 is sleeved on the outer ring wall of the fourth radially magnetized ring permanent magnet 707, and the inner ring wall of the third ring yoke 708 is in contact or clearance fit with the outer ring wall of the fourth radially magnetized ring permanent magnet 707. The two ends of the third ring yoke 708 are in contact or clearance fit with the second-end axially magnetized ring permanent magnet 718 and the middle axially magnetized ring permanent magnet 706 respectively. The fourth cylindrical yoke 709 covers the bottom of the second-end axially magnetized cylindrical permanent magnet 717, and the fourth ring yoke 710 covers the bottom of the second-end axially magnetized ring permanent magnet 718. Among them, the fourth cylindrical yoke 709 and the fourth ring yoke 710 are adhesively fixed to the non-magnetic base 719 to ensure the structural stability of the composite magnet array 7.

[0033] In this embodiment, the first end axially magnetized cylindrical permanent magnet 711, the middle axially magnetized cylindrical permanent magnet 714, the second end axially magnetized cylindrical permanent magnet 717, the first radially magnetized annular permanent magnet 713, the second radially magnetized annular permanent magnet 716, the first end axially magnetized annular permanent magnet 703, the middle axially magnetized annular permanent magnet 706, the second end axially magnetized annular permanent magnet 718, the third radially magnetized annular permanent magnet 704, and the fourth radially magnetized annular permanent magnet 707 are made of magnetic materials such as alnico-based permanent magnet materials, neodymium iron boron-based permanent magnet materials, iron chromium cobalt-based permanent magnet materials, ferrite permanent magnet materials, rare earth permanent magnet materials, or composite permanent magnet materials. The first cylindrical magnetic yoke 701, the first annular magnetic yoke 702, the second cylindrical magnetic yoke 712, the second annular magnetic yoke 705, the third cylindrical magnetic yoke 715, the third annular magnetic yoke 708, the fourth cylindrical magnetic yoke 709, and the fourth annular magnetic yoke 710 are made of soft magnetic materials, such as metal soft magnetic materials like commercially pure iron for electrical engineering, silicon steel, permalloy, iron aluminum alloy, iron silicon aluminum alloy, iron cobalt alloy, amorphous soft magnetic materials, nanocrystalline soft magnetic materials, soft magnetic composite materials, etc., and ferrite soft magnetic materials like manganese zinc ferrite and nickel zinc ferrite.

[0034] The multi-functional electromagnetic coil group 6 includes a coil skeleton 601, an inner-layer actively controllable electromagnetic force coil 602, and an outer-layer actively adjustable electromagnetic negative stiffness coil 603. The inner-layer actively controllable electromagnetic force coil 602 is fixed to the coil skeleton 601 by means of resin perfusion or bonding, etc. The outer-layer actively adjustable electromagnetic negative stiffness coil 603 is fixed to the inner-layer actively controllable electromagnetic force coil 602 by means of resin perfusion or bonding, etc. Among them, the inner-layer actively controllable electromagnetic force coil 602 includes a forward winding coil and a reverse winding coil with equal length and number of turns, and the outer-layer actively adjustable electromagnetic negative stiffness coil 603 is a single-direction winding coil. The coil skeleton 601 is fixedly connected to the bottom center position of the positive stiffness mechanical spring 5 through fasteners such as screws. The bottom end of the coil skeleton 601 extends into the air gap between the inner ring permanent magnet array and the outer ring permanent magnet array, so that the first air gap magnetic flux passes through one of the forward winding coil and the reverse winding coil, and the second air gap magnetic flux passes through the other of the forward winding coil and the reverse winding coil, and at the same time, both the first air gap magnetic flux and the second air gap magnetic flux pass through the outer-layer actively adjustable electromagnetic negative stiffness coil 603.

[0035] In this embodiment, due to the optimized magnet configuration and symmetric magnetic circuit design of the composite magnet array 7, a first air-gap magnetic flux and a second air-gap magnetic flux with equal magnitudes but opposite magnetic flux directions will be generated in the air gap between the inner-ring permanent magnet array and the outer-ring permanent magnet array. At the same time, based on the traditional Halbach array, the radial width of the axially magnetized permanent magnet is extended, resulting in the first end axially magnetized annular permanent magnet 703 embedded between the first circular yoke 702 and the second circular yoke 705, the middle axially magnetized annular permanent magnet 706 embedded between the second circular yoke 705 and the third circular yoke 708, the second end axially magnetized annular permanent magnet 718 embedded between the third circular yoke 708 and the fourth circular yoke 710, the first end axially magnetized cylindrical permanent magnet 711 embedded between the first cylindrical yoke 701 and the second cylindrical yoke 712, the middle axially magnetized cylindrical permanent magnet 714 embedded between the second cylindrical yoke 712 and the third cylindrical yoke 715, and the second end axially magnetized annular permanent magnet 718 embedded between the third cylindrical yoke 715 and the fourth cylindrical yoke 709. On the one hand, it is used to increase the magnetic flux source of the magnetic circuit, and on the other hand, it can make more full and uniform use of the yoke to reduce the overall magnetic resistance of the magnetic circuit, thereby increasing the magnetic flux density of the first air-gap magnetic flux and the second air-gap magnetic flux, and thus increasing the magnitude of the controllable electromagnetic force, the generation efficiency of the electromagnetic negative stiffness, and the adjustment range.

[0036] When the multi-functional electromagnetic coil group 6 moves in the air gap, after the inner-layer actively controllable electromagnetic force coil 602 and the outer-layer actively adjustable electromagnetic negative stiffness coil 603 are energized, the Ampere force acts on the first air-gap magnetic flux and the second air-gap magnetic flux. Among them, since the inner-layer actively controllable electromagnetic force coil 602 is composed of a series connection of a forward winding coil and a reverse winding coil with equal length and number of turns, it can match the first air-gap magnetic flux and the second air-gap magnetic flux with opposite magnetic flux directions. Therefore, the forward winding coil and the reverse winding coil will generate Ampere forces in the same direction. In addition, within the stroke range, since the effective number of turns of the first air-gap magnetic flux and the second air-gap magnetic flux remains unchanged, the resultant force output by it can be kept stable. Since the outer-layer actively adjustable electromagnetic negative stiffness coil 603 uses a single-direction winding coil, after a constant current is applied, the Ampere forces acting on the first air-gap magnetic flux and the second air-gap magnetic flux are in opposite directions. By selecting an appropriate initial height position according to the coil parameters, the resultant force at rest can be made zero. When it moves, since the number of turns of the coil in one side of the air-gap magnetic flux increases and the number of turns of the coil in the other side of the air-gap magnetic flux will decrease equally, the direction of the resultant force it receives is the direction of motion and increases with the increase of displacement, that is, it exhibits the characteristics of negative stiffness force. Therefore, the outer-layer actively adjustable electromagnetic negative stiffness coil 603 can generate a corresponding negative stiffness according to the magnitude of the current, and is connected in parallel with the positive stiffness mechanical spring 5 to achieve high-static and low-dynamic stiffness vibration isolation performance. Further, based on the intelligent control algorithm, the stable electromagnetic force output by the inner-layer actively controllable electromagnetic force coil 602 can be used to achieve active vibration isolation, thereby further improving the vibration isolation performance. Finally, efficient multi-source vibration suppression of the load 1 can be achieved.

[0037] The following further illustrates the intelligent adjustable high-static and low-dynamic stiffness integrated active vibration isolator in this embodiment with specific examples.

[0038] Figure 1 The schematic diagram of the rotational symmetry structure of the multi-functional electromagnetic coil group 6 and the composite magnet array 7 shown is as Figure 2As shown, the air gap between the inner ring permanent magnet array and the outer ring permanent magnet array is 5 mm. The dimensions of the first-end axially magnetized ring permanent magnet 703, the middle axially magnetized ring permanent magnet 706, and the second-end axially magnetized ring permanent magnet 718 of the outer ring permanent magnet array are all 7×8 mm (radius×height), and they are magnetized along the reverse Y-axis, the forward Y-axis, and the reverse Y-axis respectively. The dimensions of the third radially magnetized ring permanent magnet 704 and the fourth radially magnetized ring permanent magnet 707 of the outer ring permanent magnet array are both 5×8 mm, and they are magnetized along the reverse X-axis and the forward X-axis respectively. The dimensions of the first-end axially magnetized cylindrical permanent magnet 711, the middle axially magnetized cylindrical permanent magnet 714, and the second-end axially magnetized cylindrical permanent magnet 717 of the inner ring permanent magnet array are all 12×8 mm, and they are magnetized along the forward Y-axis, the reverse Y-axis, and the forward Y-axis respectively. The dimensions of the first radially magnetized ring permanent magnet 713 and the second radially magnetized ring permanent magnet 716 of the inner ring permanent magnet array are both 2×8 mm, and they are magnetized along the reverse X-axis and the forward X-axis respectively. The dimensions of the first cylindrical yoke 701 and the fourth cylindrical yoke 709 are both 7×2 mm, and the dimensions of the second cylindrical yoke 712 and the third cylindrical yoke 715 are both 2×8 mm. The dimensions of the first ring yoke 702 and the fourth ring yoke 710 are both 12×2 mm, and the dimensions of the second ring yoke 705 and the third ring yoke 708 are both 10×8 mm; the inner-layer actively controllable electromagnetic force coil 602 of the multifunctional electromagnetic coil group 6 has dimensions of 1.33×32 mm (thickness×height), the wire diameter of the winding is 0.35 mm, and the number of radial winding layers is 3 layers, as Figure 2 shown, the coil height of the forward winding and the coil height of the reverse winding are both 16 mm. The dimensions of the outer-layer actively controllable electromagnetic force coil are 2.66×16 mm, the wire diameter of the winding is 0.35 mm, and the number of radial winding layers is 6 layers; the inner-layer actively controllable electromagnetic force coil 602 is bonded to the coil skeleton 601, and the outer-layer actively adjustable electromagnetic negative stiffness coil 603 is bonded to the outer wall of the inner-layer actively controllable electromagnetic force coil 602. The height-direction symmetry midlines of the inner-layer actively controllable electromagnetic force coil 602 and the outer-layer actively adjustable electromagnetic negative stiffness coil 603 coincide. On the inner-layer actively controllable electromagnetic force coil 602, with this symmetry midline as the boundary, the winding directions of the upper and lower coils are opposite. The permanent magnets are all made of neodymium iron boron permanent magnet materials with the grade of N45SH, and the yokes are all made of soft iron soft magnetic materials.

[0039] The air gap magnetic flux density characteristic curve of the composite magnet array 7 is obtained through COMSOL multi-physics finite element simulation, and the results are as Figure 3As shown, the average magnetic flux density of the first air-gap magnetic flux and the second air-gap magnetic flux within each air-gap height range is 0.93 T, and the maximum air-gap magnetic flux density is 0.98 T. Moreover, the variation laws of the magnetic flux density of the two air-gaps with the height position are basically the same. First, determine the zero-position of the stroke of the multi-functional electromagnetic coil group 6. The zero-position needs to ensure that the electromagnetic force remains zero when different currents are applied to the outer actively adjustable electromagnetic negative stiffness coil 603. Therefore, it is required that the symmetry midline of the outer actively adjustable electromagnetic negative stiffness coil 603 in the height direction coincides with the symmetry midline of the composite magnet array 7 in the height direction. Additionally, within the stroke range, it is necessary to ensure that neither the upper nor the lower ends of the inner actively controllable electromagnetic force coil 602 enter the first air-gap magnetic flux and the second air-gap magnetic flux during movement, and the upper and lower ends of the outer actively adjustable electromagnetic negative stiffness coil 603 do not break away from the first air-gap magnetic flux and the second air-gap magnetic flux. Therefore, considering the symmetric configuration of the composite magnetic array, according to the height ranges of the first air-gap magnetic flux and the second air-gap magnetic flux, it can be known that the stroke range of the multi-functional electromagnetic coil group 6 is ±4 mm; correspondingly, Figure 4 are the variation laws of the electromagnetic forces on the coil at each position within the stroke range when constant currents of 0.5 A, 1 A, and 1.5 A are applied to the inner actively controllable electromagnetic force coil 602 respectively. The average forces within its stroke range are 5.96 N, 11.91 N, and 17.88 N respectively. Figure 5 are the variation laws of the electromagnetic forces on the coil at each position within the stroke range when currents of 0.3 A, 0.6 A, 0.9 A, 1.2 A, and 1.5 A are applied to the outer actively adjustable electromagnetic negative stiffness coil 603 respectively. It can be found that regardless of how the circuit size changes, the electromagnetic force at the zero stroke position is zero, and the magnitude of the electromagnetic force increases linearly with the increase in displacement. Thus, it has the characteristic of negative stiffness. According to linear fitting, the negative stiffness values under the input currents of 0.3 - 1.5 A are -761.12 N / m, -1522.31 N / m, -2283.69 N / m, -3045.27 N / m, and -3807.06 N / m respectively.

[0040] The above are only the preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the protection scope of the present invention.

Claims

1. An intelligent and adjustable integrated active vibration isolator with high static and low dynamic stiffness, characterized in that: It comprises a base frame and an active electromagnetic unit arranged on the base frame, which is used to output adjustable electromagnetic negative stiffness and controllable electromagnetic force, and use the controllable electromagnetic force to provide stable thrust for vibration isolation; The active electromagnetic unit includes a composite magnet array and a multifunctional electromagnetic coil group; The composite magnet array comprises an inner ring permanent magnet array and an outer ring permanent magnet array coaxially spaced on the inner ring permanent magnet array, an air gap between the inner ring permanent magnet array and the outer ring permanent magnet array comprises a first air gap magnetic flux and a second air gap magnetic flux adjacent to each other in the axial direction, and the magnetic flux density of the first air gap magnetic flux and the second air gap magnetic flux are equal in magnitude and opposite in direction; The multifunctional electromagnetic coil group includes an inner layer of actively controllable electromagnetic force coil and an outer layer of actively adjustable electromagnetic negative stiffness coil, wherein the inner layer of actively controllable electromagnetic force coil includes a forward winding coil and a reverse winding coil of equal length and number of turns, and the outer layer of actively adjustable electromagnetic negative stiffness coil is a unidirectional winding coil; The first air gap magnetic flux passes through one of the forward winding coil and the reverse winding coil, the second air gap magnetic flux passes through the other of the forward winding coil and the reverse winding coil, and the first air gap magnetic flux and the second air gap magnetic flux both pass through the outer layer active adjustable electromagnetic negative stiffness coil.

2. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 1 is characterized in that: The multifunctional electromagnetic coil assembly also includes a coil frame; The inner layer active controllable electromagnetic force coil is fixed on the coil frame by pouring resin, and the outer layer active adjustable electromagnetic negative stiffness coil is fixed on the inner layer active controllable electromagnetic force coil by pouring resin.

3. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 2 is characterized in that: It also includes a positive stiffness mechanical spring, which is used for bearing and is connected in parallel with the adjustable electromagnetic negative stiffness to reduce the dynamic stiffness, thereby achieving the expansion of the vibration isolation bandwidth.

4. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 3 is characterized in that: The base frame includes a vibration isolator base and a support rod arranged on the vibration isolator base; The positive stiffness mechanical spring is fixed on the support rod, the active electromagnetic unit is arranged on the vibration isolator base and is located below the positive stiffness mechanical spring, and the top end of the coil skeleton is fixedly connected to the positive stiffness mechanical spring.

5. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 4 is characterized in that: Also included is a load connection mechanism; The load connection mechanism comprises an optical axis guide rod, a guide bearing and a bearing mounting bracket, wherein the bearing mounting bracket is arranged on the support rod and located above the positive stiffness mechanical spring, and the guide bearing is arranged on the bearing mounting bracket; One end of the optical axis guide rod is connected to the positive stiffness mechanical spring, and the other end is connected to an external load after passing through the guide bearing.

6. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to any one of claims 1 to 5, characterized in that: The inner ring permanent magnet array includes a first end axially magnetized cylindrical permanent magnet, a middle axially magnetized cylindrical permanent magnet, a second end axially magnetized cylindrical permanent magnet, a first radially magnetized annular permanent magnet and a second radially magnetized annular permanent magnet; The first end axially magnetized cylindrical permanent magnet, the middle axially magnetized cylindrical permanent magnet, and the second end axially magnetized cylindrical permanent magnet are sequentially spaced from top to bottom, the first radially magnetized annular permanent magnet is located between the first end axially magnetized cylindrical permanent magnet and the middle axially magnetized cylindrical permanent magnet, and the second radially magnetized annular permanent magnet is located between the middle axially magnetized cylindrical permanent magnet and the second end axially magnetized cylindrical permanent magnet, wherein the magnetization directions of the first end axially magnetized cylindrical permanent magnet and the second end axially magnetized cylindrical permanent magnet are opposite to those of the middle axially magnetized cylindrical permanent magnet, and the magnetization directions of the first radially magnetized annular permanent magnet and the second radially magnetized annular permanent magnet are opposite; The outer ring permanent magnet array includes a first end axially magnetized annular permanent magnet, a middle axially magnetized annular permanent magnet, a second end axially magnetized annular permanent magnet, a third radially magnetized annular permanent magnet and a fourth radially magnetized annular permanent magnet; The first end axially magnetized annular permanent magnet and the first end axially magnetized cylindrical permanent magnet have the same thickness and opposite magnetization directions, and the first end axially magnetized annular permanent magnet is coaxially spaced and sleeved on the first end axially magnetized cylindrical permanent magnet with both ends flush; The intermediate axially magnetized annular permanent magnet and the intermediate axially magnetized cylindrical permanent magnet have the same thickness and opposite magnetization directions, and the intermediate axially magnetized annular permanent magnet is coaxially spaced and sleeved on the intermediate axially magnetized cylindrical permanent magnet with both ends flush; The second end axially magnetized annular permanent magnet and the second end axially magnetized cylindrical permanent magnet have the same thickness and opposite magnetization directions, and the second end axially magnetized annular permanent magnet is coaxially spaced and sleeved on the second end axially magnetized cylindrical permanent magnet with both ends flush; The third radially magnetized annular permanent magnet has the same thickness as the first radially magnetized annular permanent magnet and has the same magnetization direction; the third radially magnetized annular permanent magnet is coaxially spaced and sleeved on the first radially magnetized annular permanent magnet with both ends flush; the first air gap magnetic flux is located between the third radially magnetized annular permanent magnet and the first radially magnetized annular permanent magnet; The fourth radially magnetized annular permanent magnet has the same thickness and the same magnetization direction as the second radially magnetized annular permanent magnet. The fourth radially magnetized annular permanent magnet is coaxially spaced and sleeved on the second radially magnetized annular permanent magnet with both ends flush. The second air gap magnetic flux is located between the fourth radially magnetized annular permanent magnet and the second radially magnetized annular permanent magnet.

7. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 6, characterized in that: The top of the first end axially magnetized cylindrical permanent magnet is covered with a first cylindrical yoke, and the top of the first end axially magnetized annular permanent magnet is covered with a first annular yoke; A second cylindrical magnetic yoke is embedded in the ring opening of the first radially magnetized annular permanent magnet, and a second annular magnetic yoke is sleeved on the outer ring wall of the third radially magnetized annular permanent magnet; A third cylindrical magnetic yoke is embedded in the ring opening of the second radially magnetized annular permanent magnet, and a third annular magnetic yoke is sleeved on the outer ring wall of the fourth radially magnetized annular permanent magnet; A fourth cylindrical yoke is provided at the bottom of the second-end axially magnetized cylindrical permanent magnet, and a fourth annular yoke is covered on the top of the second-end axially magnetized annular permanent magnet.

8. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 6, characterized in that: The permanent magnets in the inner ring permanent magnet array and the outer ring permanent magnet array are made of Al-Ni-Co permanent magnet materials, Nd-Fe-B permanent magnet materials, Fe-Cr-Co permanent magnet materials, ferrite permanent magnet materials, rare earth permanent magnet materials or composite permanent magnet materials.

9. The intelligent adjustable high static and low dynamic stiffness integrated active vibration isolator according to claim 7, characterized in that: The first cylindrical yoke, the first annular yoke, the second cylindrical yoke, the second annular yoke, the third cylindrical yoke, the third annular yoke, the fourth cylindrical yoke, and the fourth annular yoke are made of soft magnetic material.

Images