1013results about "Magnetic springs" patented technology

The invention relates to a magnetic fluid damping device, which is suitable for damping long objects in spacecrafts and solves the problem of the damping of the long objects in the spacecrafts. The device comprises a non-magnetic shell (2), magnetic liquid (3), a permanent magnet (4), a nut (5), an end cover (6), a bolt (7), a screw (9), a sealing gasket (10) and an O-shaped seal ring (11). The parts are connected in a way that: the permanent magnet (4) is arranged in the non-magnetic shell (2); the end cover (6) with the O-shaped seal ring (11) is fixed to one end of the non-magnetic shell (2) by the bolt (7) and the nut (5); the magnetic liquid (3) is filled into the non-magnetic shell (2) by a threaded hole (8); and the non-magnetic shell (2) is sealed by the screw (9) and the sealing gasket (10). The device is sensitive to inertia force, can perform damping on the vibration with the characteristics of low frequency, small displacement and low accelerated speed, and has long service life and simple assembly method.

A force feedback interface device that provides force feedback to a joystick handle manipulated by a user. A force feedback device inputs control signals to a computer and outputs forces to a user of the force feedback device. The device includes a housing gripped by the user of the force feedback device and a joystick handle manipulable in at least two rotary degrees of freedom by the user, such as a gamepad. Sensors detect a position of the joystick handle and two direct drive actuators each provide torque in a rotary degree of freedom. Each of the actuators is a brushless, single phase actuator having a grounded excitation coil and a moving magnetic material. The joystick is mechanically constrained to not move past either of two limits where the torque output by the actuator in an unenergized state changes direction. The joystick handle can be oriented such that a center position is substantially at a local minimum reluctance position of the actuator, where the joystick is mechanically constrained to not move substantially past either local maximum reluctance position adjacent to the local minimum reluctance position. The local minimum reluctance position can in some embodiments provide a centering spring force on the joystick handle.

The invention discloses a magnetic liquid damping shock absorber with an arc-shaped inner wall axial section, which is suitable for shock absorption for a long object in a spacecraft. The device comprises a non-magnetic-conducting shell (1), a bolt (2), a nut (3), a permanent magnet (4), a magnetic liquid (5), a non-magnetic housing (6), an O-shaped ring (7), air hole (8), a shell inner wall surface (9) with an arc-shaped inner wall axial section, an air hole (10) and an interlayer air gap (11), wherein connection among the various portions above is as follows: the permanent magnet (4) is installed in the non-magnetic-conducting shell (1), the magnetic liquid is coated on the permanent magnet (4), and the non-magnetic housing (6) and the non-magnetic-conducting shell (1) are sealed by the O-shaped ring (7), and rigidly connected by the bolt (2) and the nut (3); the inner wall axial section of the non-magnetic-conducting shell (1) is arc-shaped, and the corresponding central angle theta is 1-15 degrees. The device is quite sensitive to an inertia force, and capable of carrying out effective shock absorption on shock with the characteristics of a low frequency, a small displacement and a low accelerated speed.

The invention discloses a magnetic liquid damping device, relates to a damping device and aims to solving the damping problem of a longer object in a spacecraft. The device consists of a non-magnetic conducting shell (2), magnetic liquid (3), a permanent magnet (4), a nut (5), an end cover (6), a bolt (7), a screw (9), a sealing gasket (10) and an O-shaped seal ring (11), wherein the parts are connected together; the permanent magnet (4) is arranged in the cavity of the non-magnetic conducting shell (2); the end cover (6) with the O-shaped seal ring (11) is fixed on one end of the non-magnetic conducting shell (2) through the bolt (7) and the nut (5); the magnetic liquid (3) is filled in the cavity of the non-magnetic conducting shell (2) through a screwed hole (8); the screw (9) and the sealing gasket (10) are used for sealing; the permanent magnet (4) is a cylinder; and 4-8 through holes are distributed in the cylinder axially. The device disclosed by the invention has good damping effect.

The invention relates to a large axial eddy current damper manufactured through a spiral transmission method. The axial eddy current damper based on the spiral transmission method comprises a spiral pair transmission assembly and a rotary eddy current damping generator. The rotary eddy current damping generator comprises an upper disc and a lower disc which are consistent in size, are vertically parallel and are made of magneto-conductive materials, wherein a rotary disc which is parallel with the upper disc and is made of electricity-conductive materials or magneto-conductive materials is arranged between the upper disc and the lower disc, the rotary disc is installed on the spiral pair transmission assembly and rotates along with the spiral pair transmission assembly, a plurality of pairs of magnets are further arranged between the upper disc and the lower disc, and the opposite magnetic poles of an upper magnet and a lower magnet of each pair of magnets are opposite in polarity. According to the axial eddy current damper based on the spiral transmission method, axial movement of a controlled structure is converted into the rotary movement of an inner structure of the damper to be controlled through a spiral pair, the control efficiency is largely improved, and the ratio between the damping force of the axial eddy current damper and the self weight is improved to the level equal to that of a viscous fluid damper or higher level.

A quasi-zero stiffness vibration isolator with annular permanent magnets used for generating negative stiffness comprises a base and an outer cylinder connected with the base, the outer permanent magnet is arranged in a top notch of the outer cylinder, an upper cover is connected with the outer cylinder, a sliding bearing is combined with a central hole of the upper cover in a sleeved mode, and a central shaft is sleeved with the sliding bearing and is in clearance fit with the sliding bearing. A sleeve and an adjusting sleeve are sequentially connected to the position, located on the lower portion of the sliding bearing, of the central shaft, and the inner permanent magnet is installed in the sleeve. A spring is arranged at the bottom of the central shaft in a sleeving mode, the bottom end of the spring is fixed to the base, and the top end of the spring is fixed to the adjusting sleeve. A mark line on the central shaft is used for representing the position of the inner permanent magnet relative to the outer permanent magnet. When the mark line coincides with the upper end face of the sliding bearing, the inner permanent magnet exactly faces the outer permanent magnet, and the isolator is in a normal working state. The quasi-zero stiffness vibration isolator has the advantages of being high in static stiffness and low in dynamic stiffness, basic stimulation with large amplitude can be isolated, and the mass of a vibration-isolated objected can be adjusted.

Provided is a tactile information supply module. The tactile information supply module includes a receiver for receiving message information from the outside, a controller for converting the message information into a tactile signal, and an operator for providing tactile information to a user based on the tactile signal, wherein the operator includes at least one tactile sensation provider comprising magnetic particles and a matrix material, and wherein the tactile sensation provider is transformed in response to an external magnetic field to provide the tactile information.

The invention discloses an electromagnetic type energy feedback shock absorber based on a Halbach permanent magnet array. Multiple groups of coil windings are arranged in an outer barrel of a belt trough, which is made of soft magnetic materials, and are introduced into and led out of a rectifying circuit via a lead; an inner barrel is provided with a Halbach permanent magnet array consisting of annular permanent magnets of different polarization directions; and the inner barrel and the outer barrel are connected by a spring. When the shock absorber is installed on a driving automobile suspension, axial relative displacement is generated between the inner barrel and the outer barrel by pavement vibrational excitation action transferred by an axle or wheels, and a coil winding magnetic linkage in the outer barrel is changed to generate induced electromotive force. Because the Halbach permanent magnet array has an obvious single-side strengthening characteristic, a magnetic field of which one side is provided with enhanced magnetic induction intensity is in sinusoidal distribution and has a small higher harmonic; and therefore, the absorber has the advantages of small volume, small quality and good energy recovery performance.

A collision energy-absorbing device includes a body member connected between the frame assembly of a motor vehicle and a bumper beam. The body member collapses as the bumper beam and the frame assembly are moved relatively toward one another during a vehicle collision. The body member has a first telescoping portion and a second telescoping portion that are connected by a connecting portion. The telescoping portions have different cross-sectional dimensions to enable the telescoping portions to move one within the other into collapsing telescoping relation as the body member collapses with the connecting portion being deformed and received between the telescoping portions. One or more protrusions extending from one of the telescoping portions interfere with relative movement of the other of the telescoping portions to retard movement of the telescoping portions into telescoping relation.

The invention discloses a magnetic liquid damping vibration attenuating device which is suitable for vibration attenuation for longer objects in a spacecraft and used for solving the problem of vibration attenuation in the spacecraft. The device comprises a non-magnet conductive shell (2), magnetic liquid (3), a permanent magnet (4), nuts (5), an end cover (6), bolts (7), screws (9), a sealing gasket (10) and an O-shaped sealing ring (11); the parts are connected as follows: the permanent magnet (4) is arranged in a cavity of the non-magnet conductive shell (2); the end cover (6) with the O-shaped sealing ring (11) is fixed on the end surface of the open end of the non-magnet conductive shell (2) by using the bolts (7) and the nuts (5); the cavity of the non-magnet conductive shell is full of magnetic liquid through a threaded hole and is sealed by using the screws and the sealing gasket. A cavity formed by the non-magnet conductive shell (2) and the end cover (6) is a ball-shaped cavity. The non-magnet conductive shell (2) and the permanent magnet (4) adopted by the device are in circular ball shapes, therefore, the magnetic liquid damping vibration attenuating device can be used for attenuating the vibration in any direction and good in vibration attenuating effect.

The invention discloses a magnetic liquid damping vibration attenuation device which is suitable for longer object vibration attenuation in a spacecraft and can be used for solving the vibration attenuation problem of longer object vibration attenuation in the spacecraft. The magnetic liquid damping vibration attenuation device comprises an end closure (1), a magnetic liquid (2), a non-magnetic-conductive shell (3) and a permanent magnet (4), wherein the permanent magnet (4) is installed in the cavity of the non-magnetic-conductive shell (3), the magnetic liquid (2) is injected into the cavity of the non-magnetic-conductive shell (3) and the end closure (1) is used for sealing. The device is very sensitive to the inertia force, the adopted end closure (1) with threads is provided with a taper angle, the taper angle is 140degrees -170degrees, the depth of the end closure screwed into the non-magnetic-conductive shell (3) can be adjusted so as to regulate the pressure applied to the magnetic liquid by the end closure (1), the permanent magnet is a cylinder, the vibration attenuation effect is good for the vibration with low frequency, small displacement and small acceleration characteristics.

The invention provides a zero-rigidity magnetic-suspension active vibration isolator and a six-degree-of-freedom vibration isolation system consisting of the vibration isolator, and belongs to the field of precise vibration isolation. The zero-rigidity magnetic-suspension active vibration isolator comprises a permanent-magnetic passive vibration isolation unit, an active vibration isolation unit and a safe limiting assembly; the permanent-magnetic passive vibration isolation unit comprise an upper magnet, a lower magnet, a middle magnet and related connection components, and all of the magnets are rectangular magnets; the active vibration isolation unit can apply location control and vibration active control in vertical and horizontal directions, and comprises a Lorentz motor, a speed sensor and a displacement sensor; the safe limiting assembly has mechanical horizontal regulation and limiting safety protection functions. The zero-rigidity magnetic-suspension active vibration isolator provided by the invention has zero rigidity in the horizontal direction, and has the characteristic of quasi-zero rigidity while having the bearing capacity in the vertical direction; the six-degree-of-freedom vibration isolation system consisting of the zero-rigidity magnetic-suspension active vibration isolator is suitable for precise machining and measuring devices sensitive to low-frequency vibration.

The invention discloses an active-passive combined vibration isolator based on positive-stiffness and negative-stiffness parallel connection. The active-passive combined vibration isolator based on positive-stiffness and negative-stiffness parallel connection comprises a basic platform (10), a load-bearing platform (30), a passive vibration isolation unit and an active vibration isolation unit, wherein the passive vibration isolation unit is provided with a positive-stiffness air spring (20) and a magnetic negative-stiffness mechanism (28) with adjustable negative stiffness in the first direction, so that the inherent frequency in the first direction is decreased, and the passive vibration isolation unit is provided with a stiffness-adjustable positive-stiffness leaf spring and a negative-stiffness inverted pendulum in the second direction, so that the inherent frequency in the second direction is decreased; the active vibration isolation unit is arranged at the outer side of the passive vibration isolation unit, the upper end of the active vibration isolation unit is linked with the load-bearing platform (30), and the lower end of the active vibration isolation unit is linked with the basic platform (10); and the active vibration isolation unit comprises displacement sensors, speed sensors, a proportional pressure valve and a voice coil motor, and the voice coil motor is used for fine adjustment of the load-bearing platform, so that vibration is further isolated. The active-passive combined vibration isolator based on positive-stiffness and negative-stiffness parallel connection has high bearing capacity, and active and passive vibration isolation of two degrees of freedom is achieved at the same time.

The invention discloses a negative stiffness adjustable zero stiffness vibration isolation device and an application method thereof, wherein the negative stiffness adjustable zero stiffness vibrationisolation device comprises a bearing table, a positive stiffness mechanism is arranged at the lower side of the bearing table, a plurality of adjustable negative stiffness mechanisms which are centrosymmetrically arranged are connected around the bearing table, the positive stiffness mechanism comprises a vertical elastic element for supporting the bearing table, and the adjustable negative stiffness mechanism comprises a horizontal elastic element for applying horizontal acting force to the bearing table; and the application method comprises the steps of installing a bearing object on the bearing table and then adjusting each height adjusting mechanism to enable the horizontal elastic element to be horizontal. The negative stiffness adjustable zero stiffness vibration isolation device canflexibly adjust the negative stiffness according to the bearing at any time, so that the negative stiffness can be adjusted according to the actual situation after bearing, the negative stiffness adjustable zero stiffness vibration isolation device can be adjusted to ensure that the negative stiffness adjustable zero stiffness vibration isolation device is in an ideal state that the dynamic stiffness is close to zero in a static load state after field installation, the failure of a vibration isolation system can be avoided, and the negative stiffness adjustable zero stiffness vibration isolation device has the advantages of simple structure, easiness in processing, convenience in loading and unloading, reasonable design and easiness in adjustment.

The invention discloses a multi-degree of freedom electromagnetic damper which belongs to the technical field of motors, solving the problems of the traditional electromagnetic damper of large damping force fluctuation and asymmetric distribution of generated damping force. The multi-degree of freedom electromagnetic damper mainly comprises a primary coil and secondary coils, wherein the primary coil mainly comprises a low-resistivity non-magnetic metal plate, the two-side secondary coils are distributed on the upper side and the lower side of the primary coil symmetrically, two air gaps are arranged between the primary coil and the two-side secondary coils, each-side secondary coil mainly comprises a yoke plate, (n+1) groups of X-direction excitation units and n groups of Y-direction excitation units, n is a positive integer, each X-direction excitation unit or Y-direction excitation unit comprises a plurality of strip-shaped permanent magnets which are sequentially and uniformly arranged on the flat yoke plates along the same direction, the magnetizing direction is vertical to a plane where the air gaps exist, magnetizing directions of every two adjacent permanent magnets are opposite, and magnetizing directions of permanent magnets on the two-side secondary coils corresponding to two sides of the primary coil are the same. The multi-degree of freedom electromagnetic damper is suitable for an electromagnetic damper.

The invention discloses a guide rail type shock isolation device. The guide rail type shock isolation device comprises an upper board, a middle board, a bottom board and guide rails. The guide rails comprise transverse guide rails and longitudinal guide rails, the transverse guide rails and the longitudinal guide rails are orthogonal, and the transverse guide rails are fixed to the bottom board and provided with a transverse sliding block which can slide along the transverse guide rails and has the function of drawing resistance. The middle board is fixed to the upper portion of the transverse sliding block and fixedly provided with the longitudinal guide rails. A longitudinal sliding block which can slide along the longitudinal guide rails and has the function of drawing resistance is arranged on the longitudinal guide rails. The upper board is fixed to the upper portion of the longitudinal sliding block and used for bearing objects. Reset springs are horizontally arranged between the upper board and the middle board and between the middle board and the bottom board respectively. The guide rail type shock isolation device not only has the function of isolating shock in any horizontal direction, but also has the shock absorption and energy absorption effects, and can be used for shock absorption and isolation of precious relics or precision equipment.

A shock absorber body 30 which makes telescopic motion in response to an input from outside has a ball screw mechanism 16 which converts the telescopic motion into rotary motion and is composed of a ball nut 17 and a screw shaft 18. A motor 32 is provided coaxially with the shock absorber body 30. The motor 32 generates electromagnetic resistance to oppose against the rotary motion which inputs into a rotary shaft 6 of the motor 32. A cylindrical member 1 or 23 which covers the shock absorber body 30 and the motor 32 from outside and whose part covering the motor 30 also serves as a motor frame is provided. Damping force which opposes against the telescopic motion of the shock absorber body 30 is generated according to electromagnetic force of the motor 32.

A permanent magnet low-frequency multidegree of freedom vibration isolation mechanism based on the negative stiffness principle comprises a lower permanent magnet, an upper permanent magnet, a rubber sheet, a lower permanent magnet fixing plate, a rubber fixing seat, an upper permanent magnet fixing plate, a rubber pressure block and a rubber sheet edge fixing pressure ring, wherein the permanent magnets are magnetized in the vertical direction and opposite for same poles. A positive stiffness system is formed by the permanent magnets under the action of repulsive force, the rubber sheet is stretched to a negative stiffness system under the action of repulsive force of the permanent magnets, two systems are combined to form a low-frequency vibration isolation mechanism, the single vibration isolation mechanism can realize three degrees of freedom low-frequency vibration isolation, and three or four systems are combined in parallel to realize the six degrees of freedom low-frequency vibration isolation. The vibration isolation mechanism can be used in vacuum without the input of external energy. The vibration isolation mechanism has the characteristics of simple structure, low cost and easy processing, and can be used in the fields like optics, acoustics, biology, advanced manufacturing equipment, semiconductor manufacturing and precision measurement, etc.

The invention relates to a power generation type car vibration energy recycling shock absorber, and provides a pinion-and-rack rotating power generation car shock absorber which aims to recycle vibration energy of a car for power generation and enables the purposes of vibration attenuation and energy recovery to be achieved. The pinion-and-rack rotating power generation car shock absorber is formed by an upper hanging ring, a dust-proof cover, a lower hanging ring, an upper hanging ring rod, a shell, a shaft, a rack, a pinion, a big hypoid gear, a small hypoid gear, a motor stator, a motor rotor, a lower hanging ring connecting base, a linear bearing, a linear bearing pedestal, three rolling bearings and an end face bearing. The pinion-and-rack rotating power generation car shock absorber has the advantages that reciprocating vibration mechanical energy of a car frame and a car body of the car can be recycled and can be converted to rotating mechanical energy through the rack and the gears, the relative rotation of the motor rotor and the motor stator is achieved so that power generation can be carried out, and the vibration attenuation can be achieved through magnetic resistance torque between the stator and the rotor and gear meshing resistance.

The invention relates to a dual-damping and dual-power-generating combined damping device comprising a magnetorheological damping temperature difference power generating type damper and an electromagnetic damping temperature difference power generating type damper which are spaced by a magnetic isolating material and a sealing material to form working spaces independent from each other. The magnetorheological damping temperature difference power generating type damper and an electromagnetic damping temperature difference power generating type damper form a synergistic dual-damping damping and synergistic dual-power-generating working mode. The device is of a novel device structure formed by integration, the objective of optimizing and improving comprehensive performance of the device is achieved, and the device is applicable to damping of automobiles, trains, ships, tanks, airplanes, machinery, projects and bridges and vibrating energy recycling for power generation.

The invention relates to a large-sized axial eddy current damper manufactured by using screw drive. The damper comprises a drive component and an eddy current damping generator, wherein the drive component comprises a screw drive pair, a stator and a rotor; the stator and the rotor are made of a magnetic conductive material; the screw drive pair comprises a screw and a nut which is arranged on the screw in a sleeving manner; the screw penetrates through an upper flange central hole of the stator and a lower flange central hole of the stator in sequence, and the nut is arranged in the stator; the rotor comprises an outer rotor and an inner rotor of which the bottom is provided with a lower connecting flange; one or more eddy current damping generators are arranged between the stator and the rotor. According to the damper, the damping coefficient and the inertial mass moment of the rotary eddy current damping part can be enlarged by hundreds of thousands of times to be converted into extremely large axial damping coefficient and axial equivalent added mass; meanwhile the problem that the axial damper with a large damping coefficient and the anti-seismic damper with a simulation speed index of being less than 1 are difficult to manufacture by using the rotary eddy current damping is solved.

A dampening device for use in a dampening system that operates to dampen and slow the movement of a closing door thereby reducing noise and the risk of injury, the dampening device including a piston and dampening apparatus that are moveable within a cylinder and an anchoring apparatus, the dampening device attached to various positions along a door frame or door panel.

The invention discloses a vehicle vibration isolator for recycling vibrating energy, comprising a vibration isolator body and an installing lining sleeve, being characterized in that vibration isolator also comprises a sleeve cylinder, a vibration isolating core, a connecting rod and a repositioning spring; the repositioning spring is provided in the sleeve cylinder; the two ends of the repositioning spring are respectively connected to the sleeve cylinder and the vibration isolator body; the vibration isolator body is provided with a cavity; the vibration isolator core can be arranged in the cavity in the moving way up and down on the vibration isolator body; the upper end of the vibration isolator core is connected to the sleeve cylinder via the connecting rod; the vibration isolator core is provided with the magnetic polity; the vibration isolator body is provided with the magnetic body by the winding. The invention absorbs the energy produced by the vibration of the vehicle by the straight line generator, directly outputting the power for the use. The vibration isolator can be used on all sorts of the vehicles such as the riding vehicle, business vehicle, electronic vehicle, hybrid power vehicle and so on, comprising the engineering vehicle and tanks and so on.

The invention provides a magnetic negative stiffness mechanism with a compact structure, and belongs to the field of ultra-precise vibration damping. The magnetic negative stiffness mechanism includes a frame part, a negative stiffness adjusting part, a flexible guiding part and a moving part. The negative stiffness mechanism utilizes the reverse repelling action of the magnet to form the negative stiffness characteristic, and the size of the negative stiffness can be adjusted through the negative stiffness adjusting part. As the ultra-low frequency vibration damper formed by combining the magnetic negative stiffness mechanism and the positive stiffness spring has extremely low dynamic stiffness, the inherent frequency of the ultra-low frequency vibration damper is greatly reduced, as a result, the vibration damper not only has excellent vibration isolation effect towards the high-frequency vibration interference, but also can effectively isolate the ultra-low frequency vibration, and the magnetic negative stiffness mechanism is applicable to the ultra-precise machining and measuring equipment sensitive to the vibration.

There is described a support system enabling supporting an object such as a platform (1) free from vibration, in that bearing elements (50) have a stiffness (k) which at a working point (z0) equals zero. A bearing element (50) comprises two magnectic couplings (51, 52) provided by permanent magnets (61, 63). One coupling (51) has a positive stiffness (k51), and the other coupling has a negative stiffness (k52); in the working point, the absolute values of those stiffnesses are equally great. Alternatively, electrostatic couplings are used.

The invention discloses an eddy current energy consumption damper for suppressing axial vibration. The eddy current energy consumption damper consists of an eddy current energy consumption unit, a magnetic buffer unit, an electromagnetic shielding case and a connecting part, wherein the eddy current energy consumption unit and the magnetic buffer unit are respectively distributed at two ends of the damper; an eddy current barrel in the eddy current energy consumption unit is inserted into a magnetic field between inner and outer permanent magnets of the eddy current energy consumption unit, and the top end of the eddy current barrel is connected with one end of the connecting part and is used for connecting an external load; the other end of the eddy current barrel is connected with a movable permanent magnet in the magnetic buffer unit at the bottom; the bottom of the damper is provided with the magnetic buffer unit which consists of a movable permanent magnet and a fixed permanent magnet which have the opposite polarity directions; the movable permanent magnet on the upper part is fixedly connected with the tail end of the eddy current barrel and moves along with the eddy current barrel; and the other fixed permanent magnet is fixed at the bottom of the damper. The eddy current energy consumption damper has the characteristics of simple structure, no contact, long service life, high rigidity, controllable damping and the like, a working medium is not required, and the current energy consumption damper has high application value in the technical field of structural vibration control.

The invention discloses an annular permanent magnet low frequency vibration isolation mechanism based on a negative stiffness theory. The mechanism comprises an upper rubber sheet, an inner annular permanent magnet fixing mandrel, an upper rubber sheet upper pressing ring, an upper rubber sheet outer pressing ring, an outer annular permanent magnet, a lower rubber sheet, a lower rubber sheet inner pressing sheet, a lower rubber sheet outer pressing ring, an outer annular permanent magnet fixing sleeve and an inner annular permanent magnet, wherein the inner annular permanent magnet is magnetized axially; the outer annular permanent magnet is radially magnetized; a positive stiffness system consists of the inner annular permanent magnet and the outer annular permanent magnet; a negative stiffness system consists of the upper rubber sheet and the lower rubber sheet; and the positive stiffness system and the negative stiffness system are used in parallel to form the low frequency vibration isolation mechanism. Three or four single-degree-of-freedom vibration isolation mechanisms are used in parallel to realize three-degree-of-freedom low frequency vibration isolation. When the vibration isolation mechanism has the largest magnetic force, the stiffness of the vibration isolation mechanism approximates to zero. Without an outside air source, the vibration isolation mechanism has a prospect of being used in vacuum, has the characteristics of simple structure and low cost, is easy to process, and can be applied to the fields of optics, acoustics, biologics, semiconductor manufacturing, precise measurement and the like.

The invention discloses a two-degree-of-freedom ultralow-frequency vibration isolator. The two-degree-of-freedom ultralow-frequency vibration isolator comprises a basic platform (10) and a load-bearing platform (30), and the basic platform (10) and the load-bearing platform (30) are connected through supporting rods. The two-degree-of-freedom ultralow-frequency vibration isolator is characterized in that the vibration isolator further comprises a positive-stiffness air spring (20) and a magnetic negative-stiffness mechanism (28) with adjustable negative stiffness, and the positive-stiffness air spring (20) and the magnetic negative-stiffness mechanism (28) form a parallel mechanism in the direction of the center axes of the basic platform and the load-bearing platform, so that the inherent frequency in the direction of the center axes of the basic platform and the load-bearing platform is decreased; and a stiffness-adjustable positive-stiffness leaf spring and a negative-stiffness inverted pendulum are arranged in the direction perpendicular to the center axes of the basic platform and the load-bearing platform and form a negative-stiffness parallel mechanism, so that the inherent frequency in the direction perpendicular to the center axes of the basic platform and the load-bearing platform is decreased. According to the vibration isolator, positive-stiffness and negative-stiffness parallel type passive structures are adopted both in the direction of the center axes of the basic platform and the load-bearing platform and in the direction perpendicular to the center axes of the basic platform and the load-bearing platform, and thus vibration of two degrees of freedom is achieved at the same time.

A quasi-zero stiffness vibration isolator connected with a magnetic spring in parallel through a spiral spring comprises a mass supporting rod, and one end of the mass supporting rod is fixedly connected with the spiral spring through threads; a permanent magnet clamped by the spiral spring, the spiral spring and the mass supporting rod move together relative to a spiral spring clamping mechanism in the axial direction, and meanwhile the spiral spring provides positive stiffness for a system in the axial direction; two annular permanent magnets fixed through the permanent magnet clamping mechanism apply attraction to the permanent magnet clamped by the spiral spring, the three permanent magnets form the magnetic spring, and non-linear restoration force and non-linear negative stiffness are provided for the system; the relative distances between the upper permanent magnet and the permanent magnet clamped by the spiral spring and between the lower permanent magnet and the permanent magnet clamped by the spiral spring can be adjusted by rotating the permanent magnet clamping mechanism. By means of the vibration isolator, intrinsic frequency of the vibration isolation system can be effectively reduced, and the vibration isolation frequency band is widened. Meanwhile, the damping characteristic of the structure is improved, and a reliable method is provided for low-frequency vibration control.