Gravity compensation device

Abstract

The application provides a gravity compensation device, and relates to the technical field of ultra-precision machining and measurement. The gravity compensation device comprises a rotor module and a stator module. The rotor module comprises a plurality of annular rotor permanent magnets. The plurality of rotor permanent magnets are arranged in a stack along an axial direction. Each two adjacent rotor permanent magnets form a group. At least two rotor permanent magnets of each group are clamped with an adjusting block. The adjusting block is used for adjusting the distance between the two rotor permanent magnets. The stator module comprises a stator permanent magnet surrounding the rotor module. The stator permanent magnet and the rotor permanent magnet are arranged in a radial gap. The stator permanent magnet and the rotor permanent magnet interact to form an axial upward gravity compensation force. The number of the rotor permanent magnets and the adjusting block and the thickness of the adjusting block are adjusted to adjust the size of the gravity compensation force. The gravity compensation device has a wide application range, and is convenient and low in cost to adjust.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultra-precision machining and measurement, in particular to a gravity compensation device. BACKGROUND

[0002] With the continuous improvement of the integration of integrated circuit devices, the precision requirement of the workbench is continuously improved, such as lithography equipment, film thickness detection equipment, etc. In order to reduce the adverse effects of mechanical contact of the workbench, such as vibration, the existing workbench can be supported by a magnetic floating gravity compensation device in a non-contact manner. However, the existing magnetic floating gravity compensation device can only be applied to a specific specification of a load, and the load range is small, and the applicability is poor. SUMMARY

[0003] The purpose of the present application includes providing a gravity compensation device to solve the technical problem that the existing magnetic floating gravity compensation device can only be applied to a specific specification of a load, and the load range is small, and the applicability is poor.

[0004] To solve the above problems, the present application provides a gravity compensation device, comprising a mover module and a stator module, the mover module comprises a plurality of annular mover permanent magnets, a plurality of the mover permanent magnets are arranged in the axial direction, every two adjacent mover permanent magnets form a group, and at least one group of two mover permanent magnets is provided with an adjusting block, the adjusting block is used for adjusting the distance between the two corresponding mover permanent magnets; the stator module comprises a stator permanent magnet surrounding the mover module, and the stator permanent magnet and the mover permanent magnet are arranged in the radial direction gap; the stator permanent magnet and the mover permanent magnet interact to form an upward gravity compensation force in the axial direction.

[0005] Optionally, the magnetization direction of each of the mover permanent magnets is axial magnetization and the magnetization direction is consistent, the magnetization direction of the stator permanent magnet is radial magnetization, and the magnetic pole of the inner wall of the stator permanent magnet is the same as the magnetic pole of the top wall of the mover permanent magnet.

[0006] Optionally, the mover module further comprises a mandrel and a bearing table, the adjusting block comprises an adjusting washer, the mover permanent magnet and the adjusting washer are both sleeved on the mandrel to form a driving body, and the top end of the driving body is connected with the bearing table; the bottom end of the mandrel is provided with a blocking piece, and the radial dimension of the blocking piece is greater than the inner diameter of the ring of the mover permanent magnet.

[0007] Optionally, at least one of the bearing table and the blocking piece is detachably fixed with the mandrel.

[0008] Optionally, the stator module further comprises a base, a top surface of the base is fixedly provided with an annular protection cylinder, an accommodating cavity is formed in the ring of the protection cylinder, and the mover permanent magnet is located in the accommodating cavity; an annular cavity is arranged on the inner side of the cylinder wall of the protection cylinder along the circumference thereof, and the stator permanent magnet is arranged in the cavity along the circumference.

[0009] Optionally, the protection cylinder comprises an inner enclosing piece and an outer enclosing piece arranged outside the inner enclosing piece, the inner enclosing piece comprises an inner side enclosing portion and a bottom enclosing portion arranged outside the inner side enclosing portion, the outer enclosing piece comprises an outer side enclosing portion and a top enclosing portion arranged inside the outer side enclosing portion, the inner side wall of the top enclosing portion is connected with the inner side enclosing portion, the bottom end of the outer side enclosing portion is connected with the bottom enclosing portion, and the inner enclosing piece and the outer enclosing piece jointly enclose the cavity.

[0010] Optionally, the gravity compensation device further comprises an actuating coil, and the actuating coil is arranged in the cavity along the circumference.

[0011] Optionally, at least one of the inner side enclosing portion, the bottom enclosing portion, the outer side enclosing portion and the top enclosing portion is provided with a cooling liquid channel along the circumference thereof, and the cooling liquid channel is used for flowing cooling liquid to cool and lower the temperature of the actuating coil.

[0012] Optionally, the inner side enclosing portion comprises an inner cylinder body and a first side enclosing plate body arranged outside the inner cylinder body, and the first side enclosing plate body is integrally formed with the bottom enclosing portion, one of the outer side wall of the inner cylinder body and the inner side wall of the first side enclosing plate body is provided with a communication groove along the circumference thereof, and the communication groove and the other jointly enclose the cooling liquid channel.

[0013] And / or, the outer side enclosing portion comprises an outer cylinder body and a second side enclosing plate body arranged outside the outer cylinder body, and the outer cylinder body is integrally formed with the top enclosing portion, one of the outer side wall of the outer cylinder body and the inner side wall of the second side enclosing plate body is provided with a communication groove along the circumference thereof, and the communication groove and the other jointly enclose the cooling liquid channel.

[0014] Optionally, the mover module further comprises a bearing table, the stator module further comprises a base, the magnetic compensation structures formed by the mover permanent magnets and the stator permanent magnets are multiple groups, the multiple groups of magnetic compensation structures are dispersedly arranged between the bearing table and the base, the mover permanent magnets of the multiple groups of magnetic compensation structures are all fixedly arranged on the bottom of the bearing table, and the stator permanent magnets are all fixedly arranged on the top of the base.

[0015] The gravity compensation device provided by the application can adjust the number of the mover permanent magnets, the number of the adjusting blocks and the thickness of the adjusting blocks when the gravity compensation is needed for the objects with different weights, changes the first magnetic field of the mover module, and makes the gravity compensation force generated by the coupling of the first magnetic field and the second magnetic field equal to the weight of the changed object to be supported, thereby increasing the application range of the gravity compensation device and realizing the gravity compensation for the objects with different specifications. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on the provided drawings.

[0017] Figure 1 The schematic diagram of the gravity compensation device provided by the present application is shown in the figure.

[0018] Figure 2 The exploded view of the gravity compensation device provided by the present application is shown in the figure.

[0019] Figure 3 The partial axial sectional view of the gravity compensation device provided by the present application is shown in the figure, wherein the number of the mover permanent magnets is two.

[0020] Figure 4 The first magnetic pole distribution diagram of the mover permanent magnet and the stator permanent magnet in the gravity compensation device provided by the present application is shown in the figure.

[0021] Figure 5 The second magnetic pole distribution diagram of the mover permanent magnet and the stator permanent magnet in the gravity compensation device provided by the present application is shown in the figure.

[0022] Figure 6 The magnetic field line distribution diagram of the gravity compensation device provided by the present application when the coil is energized is shown in the figure.

[0023] Explanation of reference signs:

[0024] 10-mover module; 20-stator module; 100-mover permanent magnet; 200-adjusting washer; 300-core shaft; 310-separator; 400-bearing table; 500-stator permanent magnet; 600-base; 700-protection cylinder; 711-inner side wall; 711a-inner cylinder body; 711b-first side wall body; 712-bottom wall; 721-outer side wall; 721a-outer cylinder body; 721b-second side wall body; 721c-fixing edge; 722-top wall; 730-containing cavity; 740-cavity; 750-cooling liquid channel; 800-actuating coil. DETAILED DESCRIPTION

[0025] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0026] The present embodiment provides a gravity compensation device, as shown in the figure, comprising a mover module 10 and a stator module 20, the mover module 10 comprises a plurality of annular mover permanent magnets 100, the plurality of mover permanent magnets 100 are arranged in axial stacking, every two adjacent mover permanent magnets 100 form a group, at least one group of two mover permanent magnets 100 is clamped with an adjusting separator, the adjusting separator is used to adjust the spacing of the corresponding two mover permanent magnets 100; the stator module 20 comprises a stator permanent magnet 500 surrounding the mover module 10, and the stator permanent magnet 500 and the mover permanent magnet 100 are arranged in radial gap; the stator permanent magnet 500 and the mover permanent magnet 100 interact to form a gravity compensation force in the axial direction. Figures 1-3 The present embodiment provides a gravity compensation device, comprising a mover module 10 capable of generating a first magnetic field and capable of moving, a stator module 20 capable of generating a second magnetic field and fixedly immovable, the first magnetic field and the second magnetic field interact in the same space to generate an axial upward force on the mover module 10, the force can be used as a gravity compensation force of the mover module 10 supporting a supported member; wherein one or more groups of adjacent two mover permanent magnets 100 in the plurality of mover permanent magnets 100 of the mover module 10 are provided with an adjusting separator, the adjusting separator adjusts the spacing of the mover permanent magnets 100 to adjust the distribution of the magnetic force lines in the first magnetic field formed by the plurality of mover permanent magnets 100, and further changes the size of the gravity compensation force generated by the interaction of the first magnetic field and the second magnetic field.

[0027]

[0028] ​In use, the number of the mover permanent magnets 100 can be selected according to the magnetic field properties (magnetic field strength, magnetic field line distribution, etc.) of the mover permanent magnets 100, the magnetic field properties of the mover permanent magnets 100, and the weight of the to-be-supported member. Then, the number of the adjusting blocks is determined according to the weight of the to-be-supported member, and the thickness of the adjusting blocks between the mover permanent magnets 100 is determined. The spacing between the mover permanent magnets 100 is determined accordingly, and the first magnetic field generated by the mover permanent magnet 100 and the adjusting blocks is determined. The mover module 10 is sleeved with the stator module 20, the first magnetic field generated by the mover module 10 and the second magnetic field generated by the stator module 20 are coupled to form a gravity compensation force in the axial upward direction, the to-be-supported member is placed on the top of the mover module 10, and the gravity compensation force is equal to the gravity of the to-be-supported member. Thus, the support effect of the gravity compensation device on the to-be-supported member is realized, and the mover module 10 and the stator module 20 are in a suspended state without rigid connection therebetween. Accordingly, the axial upward stiffness between the mover module 10 and the stator module 20 is approximately zero. Thus, the vibration transmitted from the workbench for fixing the stator module 20 to the to-be-supported member can be effectively reduced, and the stability of the support of the to-be-supported member by the mover module 10 is ensured, and the position accuracy of the to-be-supported member is ensured.

[0029] When the gravity compensation for to-be-supported members with different weights is required, the number and thickness of the adjusting blocks can be adjusted. The first magnetic field of the mover module 10 is changed so that the gravity compensation force generated by the coupling of the first magnetic field and the second magnetic field is equal to the weight of the to-be-supported member after the change. Thus, the application range of the gravity compensation device is increased, and the gravity compensation for to-be-supported members with different specifications is realized. Of course, when the weight of the to-be-supported member changes greatly, the number of the same specification mover permanent magnets 100 can be adjusted to realize large-range adjustment of the gravity compensation force. Then, the number and thickness of the adjusting blocks are selected to adjust the spacing between the mover permanent magnets 100 to realize small-range adjustment of the gravity compensation force. Compared with the prior art, when the weight of the to-be-supported member changes, different specifications of the gravity compensation device need to be selected, and the application range of the gravity compensation device is single. Or when the weight of the to-be-supported member changes in a small range, different specifications of the mover permanent magnets 100 need to be selected to realize small-range adjustment of the gravity compensation force. The replaced mover permanent magnets 100 can only be discarded and cannot be repaired for reuse. Re-processing increases the time and cost and causes waste. The gravity compensation device of the present application can use the same specification of the mover permanent magnets 100 to realize large-range adjustment of the gravity compensation force, and the number and thickness of the adjusting blocks are selected to realize small-range adjustment of the gravity compensation force. Thus, the application range of the gravity compensation device is wide, and the adjustment is convenient and low in cost.

[0030] Of course, the mover permanent magnet 100 in the gravity compensation device can also be of different specifications, and small-range adjustment of the gravity compensation force can also be realized by adjusting the number and thickness of the adjusting stoppers. Specifically, in the mover module 10, the number of the mover permanent magnets 100 can be two, three, four, etc. according to needs.

[0031] Specifically, in the embodiment, as shown in Figure 4 and Figure 5 , the magnetization directions of the mover permanent magnets 100 can all be axial magnetization and consistent, the magnetization direction of the stator permanent magnet 500 is corresponding radial magnetization, and the magnetic poles of the inner wall of the stator permanent magnet 500 are the same as those of the top wall of the mover permanent magnet 100. The magnetization directions of the plurality of mover permanent magnets 100 in the mover module 10 are consistent, so that the magnetic field coupling of the plurality of mover permanent magnets 100 is enhanced, and a first magnetic field with consistency and high magnetic field strength is formed; the second magnetic field generated by the stator permanent magnet 500 of the stator module 20 interacts with the first magnetic field, forming a gravity compensation force in the axial direction of the mover module 10 upward, and the radial and tangential rigid forces between the stator permanent magnet 500 and the mover permanent magnet 100 are approximately zero. Correspondingly, the vibration force transmitted to the mover permanent magnet 100 through the stator permanent magnet 500 and then to the workbench and the supported piece thereon is approximately zero, thereby ensuring the stability of supporting the supported piece and ensuring the position accuracy thereof.

[0032] Specifically, as shown in Figure 4 , the number of the mover permanent magnets 100 in the mover module 10 is two, and the two mover permanent magnets 100 are arranged in an axial stack with a spacing (the adjusting stopper between the two mover permanent magnets 100 is not shown), the top end of each of the two mover permanent magnets 100 is an S pole, and the bottom end of each of the two mover permanent magnets 100 is an N pole; the inner wall of the stator permanent magnet 500 of the stator module 20 is an S pole, and the outer wall of the stator permanent magnet 500 is an N pole. Or, as shown in Figure 5 , the top end of each of the two mover permanent magnets 100 is an N pole, and the bottom end of each of the two mover permanent magnets 100 is an S pole; the inner wall of the stator permanent magnet 500 of the stator module 20 is an N pole, and the outer wall of the stator permanent magnet 500 is an S pole.

[0033] Alternatively, in the embodiment, as shown in Figure 3As shown, the mover module 10 can further include a mandrel 300 and a bearing platform 400, the adjusting stopper includes an adjusting washer 200, the mover permanent magnet 100 and the adjusting washer 200 are sleeved on the mandrel 300 to form a driving body, the top end of the driving body is connected with the bearing platform 400; the bottom end of the mandrel 300 is provided with a blocking piece 310, the radial dimension of the blocking piece 310 is greater than the inner diameter of the ring of the mover permanent magnet 100. Here is a specific setting form of the mover permanent magnet 100 and the adjusting stopper in the mover module 10, the mandrel 300 serves as a mounting base to fix the axially stacked mover permanent magnet 100 and adjusting washer 200, and the blocking piece 310 limits the mover permanent magnet 100 on the bottom to prevent the mover permanent magnet 100 from falling off the bottom end of the mandrel 300; the mover permanent magnet 100, the adjusting washer 200 and the mandrel 300 together form a driving body, the top end of the driving body is connected with the bearing platform 400, the bearing platform 400 is used to bear the to-be-supported member, the second magnetic field and the first magnetic field are coupled to generate an axial upward gravity compensation force on the driving body and the bearing platform 400, thereby realizing the gravity compensation of the to-be-supported member; wherein the setting of the mandrel 300 and the bearing platform 400 can limit and fix the stacking position of the mover permanent magnet 100 and the adjusting washer 200, and the stability of the bearing platform 400 bearing the to-be-supported member is higher.

[0034] In this embodiment, for the adjustable replacement of the adjusting washer 200, the following forms can be used: at least one of the bearing platform 400 and the blocking piece 310 is detachably fixed with the mandrel 300, including three cases: one, the top end of the mandrel 300 is detachably fixed with the bearing platform 400, when the number of the mover permanent magnet 100, the number of the adjusting washer 200 and the thickness of the adjusting washer 200 need to be adjusted, the mandrel 300 can be detached from the bearing platform 400, the length of the mandrel 300 is adjusted or a mandrel 300 with a corresponding length is replaced, then the determined mover permanent magnet 100 and adjusting washer 200 are sleeved, and the top end of the mandrel 300 is connected to the bearing platform 400 again; two, the blocking piece 310 is detachably fixed with the mandrel 300, when adjustment is needed, the blocking piece 310 can be detached, the length of the mandrel 300 is adjusted, and the determined mover permanent magnet 100 and adjusting washer 200 are sleeved, then the blocking piece 310 is connected to the mandrel 300 again; three, the top end of the mandrel 300 is detachably fixed with the bearing platform 400, and the bottom end of the mandrel 300 is detachably fixed with the blocking piece 310, in this form, any one of the above two ways can be used for adjustment, which will not be described here. Among them, for the length adjustment of the mandrel 300, the mandrel 300 can be replaced; or the length of the shaft body of the mandrel 300 can be adjusted to adjust the length of the shaft body; or the connection position of the blocking piece 310 and the bottom end of the mandrel 300 can be adjusted to realize the length adjustment of the mandrel 300, such as the threaded connection of the blocking piece 310 to the bottom end of the mandrel 300.

[0035] In the second form, the top end of the mandrel 300 can be fixedly connected or integrally formed with the bearing table 400. Figure 3 As shown, the top mover permanent magnet 100 can be fixedly connected with the mandrel 300 and detachably connected with the bearing table 400. Specifically, the top mover permanent magnet 100 can be fixedly connected with the mandrel 300 and the bearing table 400 by gluing.

[0036] In the embodiment, as shown in Figure 2 and Figure 3 The stator module 20 can further include a base 600, and the top surface of the base 600 is fixedly provided with an annular protection cylinder 700. The annular protection cylinder 700 forms an accommodating cavity 730 in the ring. The mover permanent magnet 100 is located in the accommodating cavity 730. The inner wall of the protection cylinder 700 is provided with an annular cavity 740 along the circumference thereof. The stator permanent magnet 500 is circumferentially accommodated in the cavity 740. The base 600 can be used as a bottom mounting table to mount the stator permanent magnet 500 and other components and to connect with a workbench or the like. The protection cylinder 700 fixedly provided on the top surface of the base 600 is used to fix the stator permanent magnet 500 therein to improve the position accuracy of the stator permanent magnet 500 and the mover module 10. The stator permanent magnet 500 is located in the cavity 740 inside the protection cylinder 700, and the protection cylinder 700 can protect the stator permanent magnet 500 to reduce damage caused by external factors.

[0037] Specifically, in the embodiment, as shown in Figure 3 The protection cylinder 700 can include an inner enclosing member and an outer enclosing member surrounding the outer side of the inner enclosing member. The inner enclosing member includes an inner side enclosing portion 711 and a bottom enclosing portion 712 surrounding the outer side of the inner side enclosing portion 711. The outer enclosing member includes an outer side enclosing portion 721 and a top enclosing portion 722 surrounding the inner side of the outer side enclosing portion 721. The inner side wall of the top enclosing portion 722 is connected with the inner side enclosing portion 711, and the bottom end of the outer side enclosing portion 721 is connected with the bottom enclosing portion 712. The inner enclosing member and the outer enclosing member together enclose the cavity 740. Here, the protection cylinder 700 is a specific form, which includes two relatively independent components, the inner enclosing member and the outer enclosing member. The inner enclosing member is approximately "L" shaped, and the outer enclosing member is approximately "┑" shaped. During installation, the inner side enclosing portion 711 of the inner enclosing member is cylindrical, and the stator permanent magnet 500 can be sleeved on the outer side of the inner side enclosing portion 711. Then, the outer enclosing member is assembled with the inner enclosing member to enclose the stator permanent magnet 500 in the cavity 740 formed by the two members. During installation, the inner side enclosing portion 711 can guide and limit the installation of the stator permanent magnet 500. The installation accuracy of the stator permanent magnet 500 is high, and the operation is convenient.

[0038] In the embodiment, as shown in Figure 3As shown, the gravity compensation device can further include an actuating coil 800 which is circumferentially accommodated in the cavity 740. When the actuating coil 800 is in a power-off state, the mover module 10 and the stator module 20 jointly form a stable magnetic field, and correspondingly a stable gravity compensation force; as shown, Figure 6 As shown, when it is necessary to adjust the axial supporting position of the mover module 10, the actuating coil 800 can be powered, and the third magnetic field generated by the actuating coil 800 is coupled with the first magnetic field to generate an axial upward or downward force on the mover module 10 (it can also be understood that the axial force on the mover module 10 formed by the coupling of the first magnetic field, the second magnetic field and the third magnetic field is greater than or less than the gravity compensation force formed by the coupling of the first magnetic field and the second magnetic field). The mover module 10 moves upward or downward along its axial direction under the action of the force, the gravity compensation force and its own gravity until it reaches the target position. The power supply to the actuating coil 800 is stopped, and the mover module 10 is again in a stable state under the action of the stator module 20, thereby achieving axial position adjustment of the supported member and improving the applicability of the gravity compensation device. Preferably, the center horizontal section of the cylinder formed by the plurality of mover permanent magnets 100 can be coplanar with the center horizontal section of the cylinder formed by the stator permanent magnets 500 as the initial position of the mover module 10 and the stator module 20. The protective cylinder 700 can position and protect the actuating coil 800 inside it.

[0039] In this embodiment, at least one of the inner side wall 711, the bottom wall 712, the outer side wall 721 and the top wall 722 has a cooling liquid channel 750 formed therein along the circumferential direction thereof, and the cooling liquid channel 750 is used to flow cooling liquid to cool and lower the temperature of the actuating coil 800. The actuating coil 800 generates heat during the power-on process, and the cooling liquid channel 750 is provided with a water inlet and a water outlet. An external water supply device can be in communication with the water inlet to fill the cooling liquid channel 750 with cooling liquid. The cooling liquid flowing in the cooling liquid channel 750 carries away the heat generated by the actuating coil 800 to cool and lower the temperature of the actuating coil 800, thereby ensuring the normal use of the actuating coil 800 and reducing the adverse effects of a high-temperature environment on the position accuracy of the supported member. Specifically, the cooling liquid channel 750 can be helically circumferentially arranged in the protective cylinder 700, or a plurality of annular channels in communication with the water inlet and the water outlet; preferably, the cooling liquid channel 750 can be provided in each of the inner side wall 711, the bottom wall 712, the outer side wall 721 and the top wall 722.

[0040] Specifically, in this embodiment, as shown, Figure 3As shown, the inner side wall of the inner cylinder 711a and the inner side wall of the first side wall plate body 711b are both provided with a communication groove along the circumferential direction thereof, and the communication grooves together with the other one of the inner side wall of the inner cylinder 711a and the inner side wall of the first side wall plate body 711b form the cooling liquid passage 750. Here is a specific assembly form of the inner side wall 711, in which the inner cylinder 711a is internally formed with a containing cavity 730 for containing the mover module 10, and the communication grooves can be machined on the outer side wall of the inner cylinder 711a or the inner side wall of the first side wall plate body 711b in an exposed state during machining, and then the inner cylinder 711a and the first side wall plate body 711b are glued or screwed to form the inner side wall 711; wherein the first side wall plate body 711b is integrally formed with the bottom wall 712, which not only improves the operation convenience of assembling the inner wall, but also improves the connection firmness of the bottom wall 712 and the inner side wall 711.

[0041] Optionally, in the embodiment, as shown in Figure 3 the outer side wall of the outer cylinder 721a and the inner side wall of the second side wall plate body 721b are both provided with a communication groove along the circumferential direction thereof, and the communication grooves together with the other one of the outer side wall of the outer cylinder 721a and the inner side wall of the second side wall plate body 721b form the cooling liquid passage 750. Here is a specific assembly form of the outer side wall 721, in which the communication grooves can be machined on the outer side wall of the outer cylinder 721a or the inner side wall of the second side wall plate body 721b in an exposed state during machining, and then the outer cylinder 721a and the second side wall plate body 721b are glued or screwed to form the outer side wall 721; wherein the outer cylinder 721a is integrally formed with the top wall 722, which not only improves the operation convenience of assembling the outer wall, but also improves the connection firmness of the top wall 722 and the outer side wall 721.

[0042] Preferably, as shown in Figure 1 and Figure 3 the bottom wall 712 can extend outwardly beyond the outer cylinder 721a along the radial direction thereof, and the bottom end of the second side wall plate body 721b can be further provided with a fixing flange 721c along the circumferential direction thereof, which can be connected with the part of the bottom wall 712 extending outwardly beyond the outer cylinder 721a to improve the connection firmness thereof; in addition, the fixing flange 721c and the part of the bottom wall 712 extending outwardly beyond the outer cylinder 721a can increase the base area of the protection cylinder 700 to improve the stability of the protection cylinder 700 installed on the base 600.

[0043] In the embodiment, the mover module 10 can further include a bearing table 400, the stator module 20 can further include a base 600, and the magnetic compensation structures formed by the mover permanent magnets and the stator permanent magnets can be multiple groups. The multiple groups of magnetic compensation structures are dispersedly arranged between the bearing table 400 and the base 600, and the mover permanent magnets 100 of the multiple groups of magnetic compensation structures are all fixedly arranged at the bottom of the bearing table 400, and the stator permanent magnets 500 are all fixedly arranged at the top of the base 600. When multiple groups of magnetic compensation structures are arranged, the resultant force of the multiple groups of magnetic compensation structures in the axial direction upward is used as the gravity compensation force, and the multiple groups of magnetic compensation structures support different positions of the bearing table 400, so that the support stability is higher, and the gravity compensation stability of the supported object is higher. In addition, when a part of the multiple groups of magnetic compensation structures is adjusted in the axial direction, or the multiple groups of magnetic compensation structures are all adjusted in the axial direction but the adjustment is inconsistent, the multiple groups of magnetic compensation structures can drive the bearing table 400 to deflect in a direction, so as to improve the adjustment range of the gravity compensation device and improve the applicability. In addition, the multiple groups of magnetic compensation structures can jointly act on the bearing table 400, so as to further expand the adjustment range of the gravity compensation force and further improve the applicability of the gravity compensation device. Specifically, as shown in FIGS. 11 and 14, the magnetic compensation structures can be three groups, and the three groups of magnetic compensation structures are arranged in a triangle between the bearing table 400 and the base 600. When the axial positions of two groups of magnetic compensation structures are adjusted upward or remain unchanged, and the axial position of the other group of magnetic compensation structures is adjusted downward, the bearing table 400 deflects in a direction by a certain angle. Of course, the above operation is only an example, and the axial positions of the multiple groups of magnetic compensation structures can be adjusted according to actual needs, so as to adjust the deflection of the bearing table 400. In addition, the magnetic compensation structures can be two groups, four groups, or the like. Figure 1 and Figure 2

[0044] Specifically, the gravity compensation device can be used for gravity compensation of optical elements, mask plates, or other elements with high requirements for position accuracy and vibration influence in a lithography machine.

[0045] Finally, it should be noted that the relational terms herein such as first and second, and the like are used only to differentiate one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between such entities or operations. Moreover, the terms "comprising", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.​

[0046] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Numerous modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without the use of the inventive faculty. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gravity compensation device, characterized by, The device comprises a mover module (10) and a stator module (20), the mover module (10) comprises a plurality of annular mover permanent magnets (100), a plurality of the mover permanent magnets (100) are arranged along the axial direction, each two adjacent mover permanent magnets (100) form a group, at least one group of two mover permanent magnets (100) is clamped with an adjusting block, the adjusting block is used for adjusting the distance between the two mover permanent magnets (100); the stator module (20) comprises a stator permanent magnet (500) surrounding the mover module (10), and the stator permanent magnet (500) and the mover permanent magnet (100) are arranged along the radial gap; the stator permanent magnet (500) and the mover permanent magnet (100) interact to form a gravity compensation force along the axial direction. The mover module (10) further comprises a shaft (300) with adjustable length and a bearing table (400), the adjusting block comprises an adjusting washer (200), the mover permanent magnet (100) and the adjusting washer (200) are sleeved on the shaft (300) to form a driving body, the top end of the driving body is connected with the bearing table (400), the bottom end of the shaft (300) is threadedly connected with a spacer (310), the radial dimension of the spacer (310) is greater than the inner diameter of the mover permanent magnet (100). The stator module (20) further comprises a base (600), the top surface of the base (600) is fixedly provided with an annular protection cylinder (700), the protection cylinder (700) comprises an inner surrounding block and an outer surrounding block surrounding the outer side of the inner surrounding block, the inner surrounding block comprises an inner side surrounding part (711) and a bottom surrounding part (712) surrounding the outer side of the inner side surrounding part (711), the outer surrounding block comprises an outer side surrounding part (721) and a top surrounding part (722) surrounding the inner side of the outer side surrounding part (721), the inner side wall of the top surrounding part (722) is connected with the inner side surrounding part (711), the bottom end of the outer side surrounding part (721) is connected with the bottom surrounding part (712), the inner side of the inner side surrounding part (711) forms a containing cavity (730), and the inner surrounding block and the outer surrounding block jointly form a cavity (740); the mover permanent magnet (100) is located in the containing cavity (730), and the stator permanent magnet (500) is circumferentially contained in the cavity (740).

2. The gravity compensation device of claim 1, wherein, The magnetization direction of each mover permanent magnet (100) is axial magnetization, and the magnetization directions are consistent, the magnetization direction of the stator permanent magnet (500) is radial magnetization, and the magnetic pole of the inner wall of the stator permanent magnet (500) is the same as the magnetic pole of the top wall of the mover permanent magnet (100).

3. The gravity compensation device of claim 1, wherein, The gravity compensation device further comprises an actuating coil (800), the actuating coil (800) is circumferentially contained in the cavity (740).

4. The gravity compensation device of claim 3, wherein, At least one of the inner side wall (711), the bottom wall (712), the outer side wall (721) and the top wall (722) is provided with a cooling liquid channel (750) along the circumferential direction thereof, and the cooling liquid channel (750) is used for flowing cooling liquid to cool the actuating coil (800).

5. The gravity compensation device of claim 4, wherein, The inner side wall (711) comprises an inner cylinder (711a) and a first side wall plate (711b) surrounding the outer side of the inner cylinder (711a), and the first side wall plate (711b) is integrally formed with the bottom wall (712), and one of the outer side wall of the inner cylinder (711a) and the inner side wall of the first side wall plate (711b) is provided with a communication groove along the circumferential direction thereof, and the communication groove and the other one of the outer side wall of the inner cylinder (711a) and the inner side wall of the first side wall plate (711b) jointly form the cooling liquid channel (750). And / or, the outer side wall (721) comprises an outer cylinder (721a) and a second side wall plate (721b) surrounding the outer side of the outer cylinder (721a), and the outer cylinder (721a) is integrally formed with the top wall (722), and one of the outer side wall of the outer cylinder (721a) and the inner side wall of the second side wall plate (721b) is provided with a communication groove along the circumferential direction thereof, and the communication groove and the other one of the outer side wall of the outer cylinder (721a) and the inner side wall of the second side wall plate (721b) jointly form the cooling liquid channel (750).

6. The gravity compensation device of claim 1 or 2, wherein The mover permanent magnet (100) and the stator permanent magnet (500) form a plurality of groups of magnetic compensation structures, and the plurality of groups of magnetic compensation structures are dispersedly arranged between the bearing table (400) and the base (600).

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