Vibration isolator having a coil spring and an actuator

Abstract

The invention generally relates to an active vibration isolator having a coil spring which acts in a vertical direction. The invention also relates to a method for actively damping vibrations of a mounted load, for example of a mounted machine, system or device. For this purpose, there is provided a vibration isolator having an inner housing with a cavity for receiving and holding a coil spring which is arranged in the cavity of the inner housing and acts in a vertical direction, and also an outer housing at least partially surrounding the inner housing. Between the inner housing and the outer housing there is arranged an actuator which acts in a vertical direction.

Description

[0001] Vibration isolator with a coil spring and an actuator

[0002] The invention generally relates to an active vibration isolator with a coil spring acting in a vertical direction. In particular, the invention relates to a vibration isolator that can be used in a stationary vibration isolation system for supporting machines, systems, or devices, particularly in the semiconductor industry, such as systems or devices in the field of lithography, optical inspection devices, or wafer handling equipment. Furthermore, the invention also relates to a method for actively damping vibrations of a supported load, for example, a supported machine, system, or device.

[0003] Vibration isolation systems with a mechanical spring, such as a coil spring, are well known. In such a system, a load to be isolated from the floor, such as a lithography machine, is mounted on three or more vibration isolators that act at least in one vertical direction. Mechanical coil springs already enable passive vibration isolation in a very simple way, especially in the case of relatively large or heavy loads. Vibration isolation can be achieved above the natural frequency of the spring-mass system.

[0004] The isolation effect of such vibration isolation systems, especially when they are used to support sensitive machines, for example in the semiconductor industry, can be improved by designing the vibration isolation system as an active vibration isolation system.

[0005] The mechanical spring systems used are designed for the weight of the load to be supported. This is necessary because a mechanical spring no longer behaves linearly at the load limit, thus degrading the damping properties. Furthermore, the vibration isolator can also be damaged.

[0006] Since the deflection of a coil spring behaves essentially linearly with the applied force in the intended load range, it is understood that the height of the vibration-isolated load changes with its weight.

[0007] To compensate for variations in the isolated load or uneven force distribution, it is known to provide such mechanical spring systems with a height adjustment. This can be achieved quite simply, for example, using a height-adjustable spring plate, whereby the vibration isolation system can be adjusted to the rest position. Such a mechanical vibration isolator is described in the applicant's document EP 2 750 738 A1.

[0008] In certain cases, however, when adjusting the height of such mechanical spring systems, torques can occur, which can result in a horizontal force. This horizontal force component generally leads to a horizontal displacement of the vibration-isolated load or within the vibration isolator itself, which is undesirable. Horizontal displacement is particularly disadvantageous in active vibration isolation systems, as it causes the opposing components of contactless actuators to shift relative to each other.

[0009] For example, in a magnetic actuator, the gap dimensions between the magnets involved can change, which can adversely affect performance. It can also cause damage to the magnets. To prevent this, the actuator is designed as a separate component and located spatially separate from the vibration isolator to reliably rule out any damage, for example, when adjusting the mechanical spring system.

[0010] Another spring system based on a pneumatic spring is therefore proposed in document EP 3 181 944 A1. However, such a pneumatic isolation system can have other disadvantages, for example, if the load to be isolated represents a high moving mass and / or a high acceleration of the moving mass is exerted on the system. In this case, high forces are required, which, with pneumatic springs, require a correspondingly large installation space. However, the design and operation of such a pneumatic spring are considered more complex than that of a coil spring.

[0011] What is desirable is a vibration isolator that does not have these disadvantages.

[0012] The vibration isolator should have as small an installation space as possible in order to be able to use it flexibly.

[0013] The vibration isolator should also be suitable for higher loads, in particular for loads weighing 500 kg or more, preferably 1,000 kg or more.

[0014] The inventors have taken on this task.

[0015] This problem is solved surprisingly simply by a vibration isolator and a method for damping vibrations according to one of the independent claims. Preferred embodiments and further developments of the invention can be found in the respective subclaims.

[0016] The invention accordingly relates to a vibration isolator comprising an inner housing with a cavity for receiving and holding a coil spring, which is arranged in the cavity of the inner housing and acts in a vertical direction, an outer housing that surrounds the inner housing at least in sections, and an actuator that acts in a vertical direction and is arranged at least in sections between the inner housing and the outer housing. The vibration isolator can be part of a vibration isolation system that is stationary and can be used, for example, for supporting devices in the semiconductor industry.

[0017] Such a vibration isolation system can, for example, comprise a vibration-isolated table or frame on which the corresponding devices are mounted. For the purposes of this invention, "horizontal" and "vertical" refer to the main direction of the vibration isolator in the installed state.

[0018] With respect to the coil spring, the vertical direction corresponds to the orientation of the coil spring's center axis in the operating state, i.e., the axial direction. The vibration isolator is effective in this direction.

[0019] To connect the vibration isolator to the floor, the outer housing can be designed with appropriate fastening elements to create a firm connection to the floor. For this purpose, screw connections can be provided, for example, to firmly and detachably connect the vibration isolator to appropriate receptacles on the floor.

[0020] The outer housing can accommodate the inner housing within its interior, at least in part. According to a preferred embodiment of the invention, the outer housing can surround the inner housing along its outer wall, so that the inner wall of the outer housing and the outer wall of the inner housing face each other.

[0021] The outer and inner housings can be cylindrical, which can be advantageous for even force distribution and insulation. In this case, the outer and inner housings, as well as the coil spring, are advantageously arranged coaxially with each other.

[0022] In a preferred embodiment of the invention, the outer housing and the inner housing are also rigidly connected to each other in the horizontal direction. To enable the movement required for vibration isolation, the inner housing is preferably movable in the vertical direction within the outer housing. In other words, the inner housing with the coil spring can be moved in the axial or vertical direction relative to the outer housing, but is rigidly connected to the outer housing in the radial or horizontal direction.

[0023] The rigid horizontal coupling of the inner housing can be achieved by at least one spring element, preferably at least one leaf spring, which can be connected in parallel with the actuator. The leaf spring can be arranged in the working space of the vibration isolator and connect the inner housing to the outer housing.

[0024] The vibration isolator preferably comprises at least two leaf springs spaced apart from each other in the axial direction. This can particularly effectively counteract tilting of the inner housing relative to the outer housing and ensure a rigid connection in the horizontal direction.

[0025] The leaf spring can be part of a leaf spring assembly. Segmented leaf springs made of ring segments are conceivable, for example. A particularly preferred embodiment provides two leaf spring assemblies arranged axially spaced from one another, which are arranged approximately in the area of ​​the end face of the inner and outer housings.

[0026] This allows the leaf springs to be arranged interchangeably. This allows the natural frequency of the vibration isolator to be easily adjusted by exchanging the spring assemblies, allowing adaptation to different load situations. In particular, a natural frequency of over 5 Hz can be achieved, enabling short settling times.

[0027] In a preferred embodiment of the invention, the coil spring is mechanically rigidly coupled to the inner housing in the horizontal direction and thus insulates in the vertical direction. The inner housing can be designed with appropriate means for receiving and holding the coil spring, for example, spring plates, which allow the coil spring to be firmly seated in the horizontal and vertical directions.

[0028] According to the invention, a vertically acting actuator is provided, which can be arranged in the working space of the vibration isolator. This enables particularly uniform force introduction into the vibration isolator with optimal use of space. In a particularly preferred embodiment of the invention, the actuator is designed as a magnetic actuator, comprising at least one coil and one magnet, which form a magnet-coil pair. The coil and magnet can be arranged between the inner housing and the outer housing, for which purpose a corresponding cavity or working space can be provided. The working space can, for example, comprise recesses on the inner wall of the outer housing and / or recesses on the outer wall of the inner housing.

[0029] In addition to the coil spring, the actuator thus provides additional vibration isolation in the vertical direction. The actuator serves, in particular, as active vibration isolation. The vibration isolator according to the invention can therefore also be referred to as an active vibration isolator.

[0030] In a preferred embodiment, the at least one magnet-coil pair surrounds the coil spring at least in sections. In other words, the coil and / or magnet are arranged at least in sections around the coil spring.

[0031] In a particularly preferred embodiment, the at least one pair of magnet coils is ring-shaped or based on ring-shaped segments. In this way, the coil spring can be partially or preferably completely enclosed. This enables a particularly uniform force introduction by the actuator into the vibration isolator. In particular, this prevents the actuator from causing a tilting movement of the inner housing due to an uneven, one-sided force introduction.

[0032] In a preferred embodiment, the at least one coil of the actuator extends around the inner housing and is thus arranged on the outer wall of the inner housing. The at least one coil can, for example, be pressed or glued onto the inner housing. The associated magnet, in particular a permanent magnet, can be assigned to the outer housing and extend along the inner wall. It can also be glued. The magnet and associated coil are preferably arranged opposite one another, with a gap between the magnet and the coil.

[0033] Due to the rigid horizontal connection between the inner and outer housings, this gap can be designed to be particularly narrow, for example, with a radial width of less than 5 mm, preferably less than 1 mm, and particularly preferably less than 0.5 mm. This allows the working space to be designed to be correspondingly small, so that the vibration isolator can be kept compact overall. Furthermore, comparatively high forces can be generated.

[0034] In other embodiments, reversed arrangements can also be provided, i.e. an arrangement of the magnet on the outer wall of the inner housing and the coil on the inner wall of the outer housing.

[0035] According to a preferred embodiment, the vibration isolator comprises a plurality of actuators, preferably magnetic actuators, arranged adjacent to one another in the axial direction. In one embodiment, the vibration isolator comprises at least two or particularly preferably three or more actuators, in particular magnetic actuators, arranged adjacent to one another. This allows for higher forces to be generated in a compact installation space.

[0036] Preferably, adjacent pairs of magnetic coils are traversed by current in opposite directions. For this purpose, the winding direction of adjacent coils and the magnetization direction of the magnets between the adjacent pairs of magnetic coils are preferably alternated.

[0037] To enable uniform force application across the length of an odd number of magnet coil pairs, for example, three magnet coil pairs, the middle magnet coil pair can be larger than the outer magnet coil pairs to enable a higher force application at the same current. This configuration advantageously reduces the saturation of the magnetic field between the different magnet sets, which ultimately leads to a higher magnetic inductance (B) in the gap with the coil. For this purpose, the middle magnet coil pair can, for example, have twice the number of coil windings compared to the two outer magnet coil pairs.

[0038] The outer magnetic coil pairs can have the same number of coil windings. This makes it particularly easy to create two magnetic fields located adjacent to each other in the axial direction, which can be used to effect a vertical movement of the inner housing relative to the outer housing.

[0039] In the axial direction, adjacent magnet coil pairs can have a distance of approximately between 1 and 5 mm from each other, with a magnetic shield being provided between them.

[0040] In a preferred embodiment, the vibration isolator further comprises a preferably elongated insert, which serves to support the load. This insert can extend at least partially into the coil spring. At its upper end, the insert can be firmly connected to the inner housing and comprise an upper receptacle for receiving the coil spring, for example, an upper spring plate. In another embodiment, the insert can also be formed as part of the inner housing.

[0041] The insert can be formed, at least partially in the area protruding into the coil spring, with a hollow space open at the top, which can serve to accommodate a load-bearing element. The load-bearing element can be firmly connected to a base area of ​​the insert in the lower area of ​​the hollow space in both the axial and radial directions. The load-bearing element is thus held at the bottom of the insert, while it can be freely arranged in the hollow space in the upper area, allowing for radial and horizontal movement.

[0042] The load support can be particularly advantageously designed as a bending rod or pendulum, and its upper end can be connected to a load to be isolated. Suitable mounts can be provided for this purpose. A force acting horizontally on the load to be isolated can thus be absorbed by the load support. In a further aspect, the invention comprises a method for isolating a load to be supported, wherein at least one vibration isolator according to the invention is used as described above.

[0043] The method can provide for sensors to be placed on the load to be isolated and / or on the floor. A control loop can then control at least one actuator of the vibration isolator, which actively counteracts any vibrations that occur. The sensor can be designed, for example, as a motion or acceleration sensor.

[0044] In yet another aspect, the invention comprises a device, in particular a lithography device or system, an optical inspection device, a system or device for handling wafers or substrates, wherein the device comprises at least one vibration isolator as described above for vibration isolation. In preferred embodiments, such devices can comprise at least three such vibration isolators for a three-point mounting.

[0045] It is also conceivable and possible to operate two such vibration isolators together, wherein these two vibration isolators are arranged rotated by 90° to each other, so that active vibration isolation can be enabled both in a first, for example vertical, and a second, for example horizontal, direction.

[0046] The vibration isolator according to the invention is characterized by a small installation space and can therefore be used very flexibly.

[0047] In addition, the vibration isolator according to the invention can also be used for higher loads, in particular for loads which have a weight of 500 kg or more, for example 1,000 kg or more or even 1,500 kg or more.

[0048] Further details of the invention will become apparent from the description of the illustrated embodiments and the appended claims. The drawings show:

[0049] Fig. 1 shows an embodiment of a vibration isolator according to the invention in section,

[0050] Fig. 2 shows the vibration isolator from Fig. 1 in an oblique view,

[0051] Fig. 3 shows a schematic side view of a vibration isolation system,

[0052] Fig. 4 shows the vibration isolator from Fig. 2 in an oblique view in section,

[0053] Fig. 5 shows a section comprising the side wall of the vibration isolator according to the invention in section and

[0054] Fig. 6 shows a magnetic field that occurs during operation in the area of ​​the side wall from Fig. 5.

[0055] Detailed description of preferred embodiments

[0056] In the following detailed description of preferred embodiments, for the sake of clarity, like reference numerals designate substantially similar parts in or on these embodiments. However, to better illustrate the invention, the preferred embodiments illustrated in the figures are not always drawn to scale.

[0057] Fig. 1 shows an embodiment of a vibration isolator 10 according to the invention in section.

[0058] The vibration isolator 10 shown comprises an inner housing 20 with a cavity 21 for receiving and holding a helical spring 50, which is arranged in the cavity 21 of the inner housing 20 and acts in a vertical direction, an outer housing 30 which surrounds the inner housing 20 at least in sections, and an actuator 40 which acts in a vertical direction and is arranged between the inner housing 20 and the outer housing 30.

[0059] The vibration isolator 10 can be part of a vibration isolation system 1 which is installed stationary and which can be used, for example, for the storage of devices in the semiconductor industry.

[0060] Such a vibration isolation system 1 can, for example, comprise a vibration-isolated table 4 or frame on which the corresponding devices are mounted, e.g., a scanning electron microscope 5. A purely schematic side view of a vibration isolation system 1 is shown in Fig. 3. The table 4 and a device 5 located thereon, which serves as a load to be supported, can be isolated from the floor 2 by means of vibration isolators 10. In the exemplary embodiment, a total of four such vibration isolators 10 are provided.

[0061] To connect the vibration isolator 10 to the floor, the outer housing 30 can be designed with appropriate fastening means to create a firm connection to the floor or a mounting plate 3. For this purpose, screw connections 31 can be provided, for example, to firmly and detachably connect the vibration isolator to corresponding mountings.

[0062] The outer housing 30 can accommodate the inner housing 20 in its interior, at least in part or in sections, and is also formed with a hollow space for this purpose, which is also referred to below as the working space 32.

[0063] In the illustrated embodiment, the outer housing 30 almost completely surrounds the inner housing 20, so that the inner wall 33 of the outer housing 30 and the outer wall 23 of the inner housing 20 face each other. It is not absolutely necessary for the outer housing 30 to completely enclose the inner housing 20 in the axial direction. The inner housing 20 can also protrude, for example, which, however, can lead to a reduction in stability, particularly in the horizontal direction.

[0064] In the exemplary embodiment, the outer and inner housings are cylindrical, which has proven advantageous and suitable for uniform load absorption and damping. This allows the outer and inner housings 20, 30, as well as the coil spring 50, to be arranged coaxially with each other to the center line 51, which is very useful for uniform weight distribution and homogeneous load distribution.

[0065] The outer housing 30 and the inner housing 20 are mechanically rigidly connected to each other in the horizontal direction.

[0066] To enable the movement required for vibration isolation, the inner housing 20 is mounted vertically movable within the outer housing 30. In other words, the inner housing 20 with the coil spring 50 can be moved axially or vertically relative to the outer housing 30.

[0067] In the exemplary embodiment, the rigid horizontal coupling of the inner housing 20 is achieved by two leaf spring assemblies 34 as vertically acting spring elements, which are connected parallel to the actuator 40. The leaf spring assemblies 34 are arranged in the working chamber 32 of the vibration isolator 10 and connect the inner housing 20 to the outer housing 30.

[0068] In the exemplary embodiment, the vibration isolator 10 comprises two axially spaced-apart leaf spring assemblies 34, which are arranged on the respective end faces of the inner and outer housings 20, 30 and thus provide the greatest possible stability in the horizontal direction. This counteracts tilting of the inner housing 20 relative to the outer housing 30, thus creating a rigid connection in the horizontal direction.

[0069] A leaf spring assembly 34 comprises several leaf springs. Instead of leaf springs, other spring elements are also conceivable and possible, such as disc springs. The leaf spring assemblies 34 are arranged in an easily replaceable manner. For this purpose, a clamping ring 35 is provided on each end face, with which the leaf spring assemblies 34 can be firmly and detachably connected to the outer housing 30, thereby holding the leaf spring assemblies 34.

[0070] Replacing the spring elements allows the natural frequency of the vibration isolator 10 to be easily adjusted, allowing adaptation to different load situations. In particular, a natural frequency of over 5 Hz can be achieved to achieve short settling times.

[0071] The coil spring 50 is mechanically rigidly coupled to the inner housing 20 in the horizontal direction and thus isolates it in the vertical direction. The inner housing 20 is designed with appropriate means for receiving and holding the coil spring 50, in this example with a lower spring plate 24, which allows the coil spring 50 to be firmly seated in the horizontal and vertical directions. The spring plate 24 can be moved in the axial direction by means of an adjuster 52 to adjust its height.

[0072] According to the invention, an actuator acting in the vertical direction is provided, which is arranged in the working space of the vibration isolator and is designated as a whole by the reference numeral

[0073] 40, 40a. The actuator 40, 40a is designed as a linear motor with a rectilinear motion path and enables a particularly uniform force introduction into the vibration isolator 10.

[0074] In the embodiment, the actuator 40, 40a is designed as a magnetic actuator, comprising coils

[0075] 41, 41a and magnets 42, 42a, each forming a pair of magnet coils. Coil 41 and magnet 42 are arranged in the working space 32 between the inner housing 20 and the outer housing 30 and form a pair of magnet coils. Recesses on the inner wall of the outer housing 30 and / or recesses on the outer wall of the inner housing 20 are formed in the working space 32 to accommodate the magnets 42 or coils 41. In the exemplary embodiment, the coils are pressed or glued onto the outer wall of the inner housing 20. The inner housing 20 is advantageously made of a ferrous material, preferably steel. The magnets 42 are inserted and glued into precisely fitting, opposing recesses on the inner wall of the outer housing 30. The actuator 40, 40a thus enables additional vibration isolation in the vertical direction parallel to the coil spring 50. The actuator 40, 40a represents the active element of the vibration isolator 10.

[0076] In the illustrated embodiment, a total of three magnetic coil pairs are provided, which completely surround the coil spring 50 and extend in the axial direction approximately along the length of the coil spring 50, which represents a favorable arrangement with regard to a compact design of the vibration isolator 10 while at the same time ensuring high stability.

[0077] In the illustrated embodiment, the magnet coil pairs are ring-shaped. This allows the coil spring 50 to be completely enclosed. This enables a particularly uniform force introduction by the actuator 40, 40a into the vibration isolator 10. In particular, this prevents the actuator 40, 40a from causing a tilting movement of the inner housing 20 due to an uneven, one-sided force introduction.

[0078] In the illustrated embodiment, the windings of the coils 41 of the actuator 40, 40a extend around the outer wall of the inner housing 20. The associated magnet 42, a permanent magnet in the illustrated embodiment, is assigned to the outer housing 30 and arranged at a short distance from the coil 41 on the inner wall.

[0079] Accordingly, the magnets 42 and the associated coils 41 are arranged opposite one another, with a gap between magnet 42 and coil 41.

[0080] Due to the rigid horizontal connection between the inner and outer housings 20, 30, this gap is designed to be particularly narrow. In the exemplary embodiment, the gap has a width of less than 5 mm, preferably less than 1 mm, and particularly preferably less than 0.5 mm. This makes it possible, on the one hand, to design the working space 32 correspondingly small, so that the vibration isolator 10 can be kept compact overall. On the other hand, comparatively high forces can be generated. A reversed arrangement of magnet 42 and coil 41 is also possible and conceivable. In the embodiment shown, the vibration isolator 10 comprises three actuators 40, 40a connected in parallel, in the example magnetic actuators or magnetic coil pairs, which are arranged next to one another in the axial direction.In general, embodiments are possible and conceivable which comprise more than one actuator 40, 40a, for example two or four or five or more actuators 40, 40a arranged next to one another, in particular magnetic actuators.

[0081] This allows for higher forces to be generated within a compact working space of 32. Current flows through adjacent pairs of magnet coils in opposite directions. In an arrangement with three pairs of magnet coils, two axially spaced magnetic fields can be created.

[0082] In order to enable uniform force introduction over the length with an odd number of magnet coil pairs, for example three or five magnet coil pairs, the middle magnet coil pair, designated by reference numeral 40a in the example shown, is larger than the outer magnet coil pairs or actuators 40 in order to enable the same or greater force introduction with the same current. For this purpose, the middle magnet coil pair 40a with coil 41a and magnet 42a comprises twice the number of coil windings of coil 41a compared to the two outer magnet coil pairs. It is also possible to select a different, in particular larger, cable cross-section or a combination of a different cable cross-section and a different number of windings. The outer magnet coil pairs are designed identically in terms of their performance parameters.

[0083] In the axial direction, adjacent magnet coil pairs are spaced apart by a certain distance, which in this embodiment is between 1 and 5 mm. To reduce these distances, a shielding spacer 43 is provided between adjacent magnet coil pairs in this embodiment.

[0084] In the illustrated embodiment, the vibration isolator 10 further comprises an elongated insert 25, which serves to absorb the load. This insert 25 protrudes predominantly into the coil spring 50. At its upper end, the insert 25 is firmly connected to the inner housing 20.

[0085] The insert 25 comprises an upper receptacle for receiving the coil spring, in the example an upper spring plate 24. In another embodiment, the insert 25, also together with the upper spring plate 24, can be formed as part of the inner housing 20.

[0086] In the area protruding into the helical spring 50, the insert 25 is formed with an upwardly open cavity which serves to accommodate a load-bearing element 53. The load-bearing element 53 is arranged coaxially to the insert 25 and the helical spring 50 and, in the lower area of ​​the cavity, is firmly connected in the axial and radial directions to a base area of ​​the insert 25. The load-bearing element 53 is thus held at the base of the insert. In the upper area or on the upper end face of the insert 25, the load-bearing element 53 is arranged freely in the horizontal direction within the cavity, thus allowing for radial movement.

[0087] In this exemplary embodiment, the load support 53 is designed as a bending rod. Its upper end can be connected to the load to be isolated. For this purpose, an additional support 54 is provided in this exemplary embodiment. The load to be isolated is not shown in this illustration. A force acting horizontally on the load to be isolated can therefore be absorbed by the load support 53.

[0088] Fig. 2 shows the vibration isolator 10 in an oblique view. A lateral recess 36 allows the height to be adjusted when the vibration isolator 10 is installed. The vibration isolator 10 has a total height of approximately 150 mm and a diameter of approximately 130 mm, making it very compact. The coil spring extends approximately 90 mm in the axial direction. The three pairs of magnet coils are distributed over approximately this distance, with the middle pair of magnet coils having approximately twice the axial extension of each of the outer pairs. With these dimensions, a stroke of approximately 1.5 mm or even more is possible.

[0089] Fig. 4 shows the vibration isolator 10 from Fig. 2 in an oblique sectional view. Fig. 5 shows a section of the side wall of the inner and outer housings 20, 30 of the vibration isolator 10 in section.

[0090] Fig. 6 shows a magnetic field that develops during operation in this area of ​​the side wall of the vibration isolator 10. Two magnetic fields 44 that are axially spaced from each other are clearly visible. The sectional view schematically depicts the course of the magnetic lines with reference numeral 45.

[0091] The invention thus provides a method for isolating a load to be supported, e.g. a scanning electron microscope 5, a lithography device or a lithography system, an optical inspection device, a system or device for handling wafers or substrates or other device or system which places particularly high demands on vibration isolation.

[0092] The invention further includes a device, for example a lithography device or system, an optical inspection device, a system or device for handling wafers or substrates, wherein at least one vibration isolator 10 as described above is used.

Claims

A vibration isolator comprising an inner housing with a cavity for receiving and retaining a helical spring, which is arranged in the cavity of the inner housing and acts in a vertical direction, an outer housing that at least partially surrounds the inner housing, and an actuator acting in a vertical direction, which is arranged between the inner housing and the outer housing. A vibration isolator according to the preceding claim, characterized in that at least one spring element, preferably at least one leaf spring, is provided between the outer and inner housings, which enables axial movement of the inner housing relative to the outer housing. A vibration isolator according to any one of the preceding claims, characterized in that at least two leaf springs are provided, spaced apart from each other in the axial direction, which are preferably designed as leaf spring assemblies.A vibration isolator according to any of the preceding claims, characterized in that the actuator is designed as a magnetic actuator, comprising at least one coil and one magnet, which form a magnetic coil pair. A vibration isolator according to any of the preceding claims, characterized in that recesses are provided in a working space for receiving the coil and / or magnet of the magnetic actuator. A vibration isolator according to any of the preceding claims, characterized in that the at least one magnetic coil pair surrounds the helical spring at least partially. A vibration isolator according to any of the preceding claims, characterized in that the at least one pair of magnet coils is ring-shaped and completely encloses the helical spring, at least partially. A vibration isolator according to any of the preceding claims, characterized in that a plurality of actuators, in particular pairs of magnet coils, are provided, preferably two, more preferably three or more pairs of magnet coils, which are arranged adjacent to one another in the axial direction, wherein the winding direction of adjacent coils and the magnetization direction of the magnets between the adjacent pairs of magnet coils preferably alternate. A vibration isolator according to any of the preceding claims, characterized in that the distance between two adjacent pairs of magnet coils is between 1 and 5 mm.A vibration isolator according to any of the preceding claims, characterized in that the coil of at least one pair of magnet coils is arranged on the outer wall of the inner housing and / or that the associated magnet is arranged on the inner wall of the outer housing. A vibration isolator according to any of the preceding claims, characterized in that a gap is provided between the magnet and the coil of a pair of magnet coils, wherein the gap has a width of less than 5 mm, preferably less than 1 mm, and particularly preferably less than 0.5 mm. A vibration isolator according to any of the preceding claims, further comprising an insert which projects at least partially into the helical spring, preferably with a cavity open at the top.

13. Vibration isolator according to the preceding claim, characterized in that the insert is connected to a load-bearing element which is firmly connected to the insert in the axial and radial direction.

14. Vibration isolator according to the preceding claim, characterized in that the load-bearing element projects at least partially into the cavity of the insert and / or that the load-bearing element projects at least partially into the coil spring.

15. Vibration isolator according to one of the two preceding claims, characterized in that the load-bearing element is connected at its lower end to the base of the insert and / or can be connected at its upper end to a load or load-bearing element to be isolated.

16. Vibration isolator according to one of the three preceding claims, characterized in that the load bearing is designed as a bending rod or hinged pendulum.

17. Vibration isolator according to one of the preceding claims, characterized in that the helical spring is mechanically rigidly connected to the inner housing in the horizontal direction.

18. Method for isolating a load to be stored, comprising a vibration isolator according to one of the preceding claims.

19. Device, in particular lithography device or system, optical inspection device, system or equipment for handling wafers or substrates, comprising at least one vibration isolator according to any one of the preceding claims.

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