Magnetic suspension gravity balancer
By designing a magnetic levitation gravity balancer, using specific magnetic rings and waterway structures, the static force adjustment and dynamic force compensation of the magnetic levitation workpiece table are achieved, solving the problems of large output fluctuations and difficult static force adjustment, and improving precision positioning and vibration isolation performance.
Patent Information
- Application Number
- CN202421650900.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-07-12
AI Technical Summary
The output of existing magnetic levitation workpiece tables fluctuates greatly and the static force is difficult to adjust, which affects precision positioning and vibration isolation performance.
A magnetic levitation gravity balancer is designed, including a stator assembly, a rotor assembly and a regulation assembly. Through the magnetic charging direction of a specific magnetic ring and the design of the waterway, the load gravity is compensated by the magnetic levitation force, and combined with current adjustment to achieve static force adjustment and dynamic force compensation.
It achieves static force fluctuations of less than 2%, and fluctuations of less than 2% within the adjustable range of static force. It has dynamic force compensation function, low temperature rise, and is suitable for extreme environments.
Smart Images
Figure CN223067019U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of precision component manufacturing, in particular to a magnetic levitation gravity balancer. Background Art
[0002] In precision manufacturing, precision positioning and vibration isolation are one of the core technical problems of the whole system. For example, in extreme ultraviolet lithography machines, one of the key components affecting production yield and manufacturing line width is the high-precision worktable. Its core function is to carry wafers or masks and achieve precise positioning and movement in six degrees of freedom. At the same time, during the wafer etching process, it will be affected by some external environmental interferences, such as low-frequency ground vibration, high acceleration of the mask table movement, and vibration caused by the movement of its own large-inertia components. In addition, the movements of the worktable in each degree of freedom are coupled with each other. How to isolate external vibration interference during this complex operation and at the same time achieve nanometer-level repeat positioning accuracy poses high requirements for the design of the worktable.
[0003] Therefore, how to design a precise support mechanism to effectively eliminate assembly positioning errors and isolate ground vibration interference and achieve ultra-high positioning accuracy of the platform is a great challenge. It can be said that precision positioning and vibration isolation are the key support technologies for realizing the assembly, measurement, and ultra-precision processes of the above-mentioned precision instruments.
[0004] Currently, the general methods for realizing precision positioning compensation of precision worktables on the market include: mechanical structure types such as precision lead screw pairs and rolling guides, flexible hinge types; air-floating types such as air springs and air-floating guides; piezoelectric ceramic drive and voice coil motor hybrid types, etc. For precision positioning, some traditional mechanical structures or kinematic pairs can indeed achieve high precision. For example, the displacement resolution of a flexible hinge micro-motion mechanism can reach 1 nm. However, due to its rigid connection, the system stiffness is relatively high, and its vibration isolation performance is average. When there are external disturbances, its positioning accuracy will be greatly affected.
[0005] Magnetic levitation worktables have attracted much attention due to their advantages such as no energy consumption, no contact friction, no need for lubrication, and high reliability. Compared with traditional mechanical structure worktables, magnetic levitation worktables can achieve load gravity compensation or cancellation with low suspension stiffness, enabling the load after balancing gravity to achieve precise positioning while effectively isolating external vibration interference. In addition, compared with air-floating types, magnetic levitation worktables are also easier to implement, without the need for a dedicated air supply system, which can greatly reduce the system complexity. Therefore, magnetic levitation worktables are also often used in extreme environments such as absolute vacuum.
[0006] Existing magnetic levitation worktables have large output fluctuations and it is difficult to adjust the static force. Summary of the Utility Model
[0007] The technical problem to be solved by the embodiments of the present utility model is to provide a magnetic levitation gravity balancer to reduce output fluctuations and achieve adjustment.
[0008] To solve the above technical problem, the embodiments of the present utility model propose a magnetic levitation gravity balancer, including a stator assembly, a rotor assembly, and an adjustment assembly. The stator assembly includes a stator body. The rotor assembly includes a rotor body. The rotor body is arranged on the stator body. The rotor body is hollow. Inside the stator body, a first stator magnetic ring, a coil, and a second stator magnetic ring are arranged in sequence from top to bottom. On the outer periphery of the rotor body, a first rotor magnetic ring, a second rotor magnetic ring, and a third rotor magnetic ring are arranged in sequence from top to bottom. The adjustment assembly includes an adjustment column. The upper end of the adjustment column is located inside the rotor body. An adjustment magnetic ring is arranged on the outer periphery of the upper end of the adjustment column. The magnetization directions of the first stator magnetic ring, the second stator magnetic ring, and the second rotor magnetic ring are radial. The magnetization directions of the first rotor magnetic ring, the third rotor magnetic ring, and the adjustment magnetic ring are axial.
[0009] Further, the magnetic field directions of the first stator magnetic ring and the second rotor magnetic ring are the same, and the magnetic field directions of the first stator magnetic ring and the second stator magnetic ring are opposite; the magnetic field directions of the third rotor magnetic ring and the first rotor magnetic ring are opposite, and the magnetic field directions of the third rotor magnetic ring and the adjustment magnetic ring are the same.
[0010] Further, a water inlet and a water outlet are arranged on the stator body. A water channel is arranged inside the stator body corresponding to the coil. The head and tail ends of the water channel are respectively communicated with the water inlet and the water outlet.
[0011] Further, the water channel is spiral or cylindrical.
[0012] Further, the adjustment assembly further includes a locking nut for locking the adjustment column. The adjustment column and the locking nut are threadedly connected.
[0013] Further, spacers are arranged between the first stator magnetic ring and the coil, between the coil and the second stator magnetic ring, between the first rotor magnetic ring and the second rotor magnetic ring, and between the second rotor magnetic ring and the third rotor magnetic ring.
[0014] Further, the inner walls of the first stator magnetic ring, the coil, and the second stator magnetic ring are flush, and the outer peripheries of the first rotor magnetic ring, the second rotor magnetic ring, and the third rotor magnetic ring are flush.
[0015] Further, a gap is left between the second rotor magnetic ring and the coil, and between the adjustment magnetic ring and the inner wall of the rotor body.
[0016] Further, the adjustment column and the bottom of the stator body are threadedly connected.
[0017] The beneficial effects of the present utility model are as follows: The static force of the present utility model has small fluctuations, with a fluctuation less than 2%; the static force of the present utility model is adjustable within ±10%, and the static force fluctuation within the adjustable range is also less than 2%; the present utility model has the function of dynamic force compensation; the temperature rise of the present utility model is low. Description of the Drawings
[0018] Figure 1 Fig. is a three-dimensional structure diagram of the magnetic levitation gravity balancer according to an embodiment of the present utility model from one angle.
[0019] Figure 2 Fig. is a three-dimensional structure diagram of the magnetic levitation gravity balancer according to an embodiment of the present utility model from another angle.
[0020] Figure 3 Fig. is a three-dimensional structure diagram of the mover assembly and the adjustment assembly according to an embodiment of the present utility model.
[0021] Figure 4 Fig. is an internal structure diagram of the magnetic levitation gravity balancer according to an embodiment of the present utility model.
[0022] Figure 5 Fig. is Figure 4 a cross-sectional view taken along line C-C in
[0023] Figure 6 Fig. is Figure 5 a schematic diagram of the magnetization direction of an embodiment of
[0024] Figure 7 Fig. is Figure 5 a schematic diagram of the magnetization direction of another embodiment of
[0025] Figure 8 Fig. is a cross-sectional view of the water channel of an embodiment of the present utility model.
[0026] Figure 9 Fig. is a cross-sectional view of the water channel of another embodiment of the present utility model.
[0027] Figure 10 Fig. is a top view of the magnetic levitation gravity balancer according to an embodiment of the present utility model.
[0028] Figure 11 Fig. is Figure 10 a cross-sectional view taken along line B-B in
[0029] Figure 12 Fig. is an exploded view of the magnetic levitation gravity balancer according to an embodiment of the present utility model.
[0030] Description of the Reference Numerals in the Drawings
[0031] Spacer 1, stator assembly 10, stator body 11, first stator magnetic ring 12, coil 13, second stator magnetic ring 14, water inlet 15, water outlet 16, water channel 17, rotor assembly 20, rotor body 21, first rotor magnetic ring 22, second rotor magnetic ring 23, third rotor magnetic ring 24, bearing surface 25, adjustment assembly 30, adjustment column 31, adjustment magnetic ring 32, lock nut 33. Detailed implementation
[0032] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following further describes the present invention in detail with reference to the drawings and specific embodiments.
[0033] In the embodiments of the present invention, if there are directional indications (such as up, down, left, right, front, back...), they are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.
[0034] In addition, in the present invention, the descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature.
[0035] Please refer to Figures 1 to 12 , the magnetic levitation gravity balancer of the embodiments of the present invention includes a stator assembly, a rotor assembly, and an adjustment assembly.
[0036] The stator assembly includes a stator body. The rotor assembly includes a rotor body, and a bearing surface is provided at the top of the rotor body. The bearing surface is a horizontal plane and is used to support the load plate. The stator body is cylindrical to facilitate the placement of the rotor assembly. The rotor body is provided on the stator body. The rotor body is hollow (i.e., a through hole is provided in the middle of the rotor body) to facilitate the adjustment column to pass through. In specific applications, the magnetic levitation gravity balancer of the present invention is provided under the load plate to support the load plate. The adjustment column, the stator body, and the rotor body are all made of non-magnetic materials.
[0037] A first stator magnetic ring, a coil, and a second stator magnetic ring are coaxially arranged in the stator body from top to bottom in sequence. A first rotor magnetic ring, a second rotor magnetic ring, and a third rotor magnetic ring are coaxially arranged on the outer periphery of the rotor body from top to bottom in sequence.
[0038] The adjusting component includes an adjusting column. An opening is provided at the bottom of the stator body, and internal threads are provided on the inner wall of the opening. The upper end (i.e., the upper half) of the adjusting column passes through the opening at the bottom of the stator and is located inside the rotor body. External threads corresponding to the external threads are provided on the outer periphery of the lower end (i.e., the lower half) of the adjusting column. The adjusting column is threadedly connected to the bottom of the stator body. An adjusting magnetic ring is provided on the outer periphery of the upper end (i.e., the upper half) of the adjusting column. In the present utility model, the up-and-down position of the adjusting magnetic ring is adjusted by rotating the adjusting column.
[0039] The adjusting magnetic ring is beneficial to the generation of static force. When the adjusting column is rotated, when the adjusting magnetic ring moves upward axially along with the adjusting column, the static force will gradually increase to achieve the function of adjustable static force.
[0040] Please refer to Figures 4 to 7 , the magnetization directions of the first stator magnetic ring, the second stator magnetic ring, and the second rotor magnetic ring are radial. In specific implementation, the magnetic rings can all adopt radially magnetized rings. Preferably, the radially magnetized ring is composed of a plurality of tile-shaped parallel magnetized blocks spliced together to facilitate production and assembly. The magnetization directions of the first rotor magnetic ring, the third rotor magnetic ring, and the adjusting magnetic ring are axial (i.e., the vertical direction in Figure 5 ).
[0041] Repulsive and attractive characteristics are generated between the first stator magnetic ring and the first rotor magnetic ring, and between the second stator magnetic ring and the third rotor magnetic ring, generating static force, i.e., magnetic levitation force. Between the second rotor magnetic ring and the coil, Lorentz force is generated due to the coil cutting the magnetic field, generating dynamic force. In the present utility model, the direction of the dynamic force can be adjusted by changing the direction of the current in the coil; the magnitude of the dynamic force can be adjusted by adjusting the magnitude of the current in the coil.
[0042] As an implementation manner, the magnetic field directions of the first stator magnetic ring and the second rotor magnetic ring are the same, and the magnetic field directions of the first stator magnetic ring and the second stator magnetic ring are opposite; the magnetic field directions of the third rotor magnetic ring and the first rotor magnetic ring are opposite, and the magnetic field directions of the third rotor magnetic ring and the adjusting magnetic ring are the same.
[0043] As an implementation manner, a water inlet and a water outlet are provided on the stator body. A water channel is provided inside the stator body corresponding to the coil. The head and tail ends of the water channel are respectively communicated with the water inlet and the water outlet. The water channel is very close to the coil, which is beneficial to the heat dissipation of the coil.
[0044] As an implementation manner, please refer to Figures 8 to 9 , the water channel is spiral or cylindrical.
[0045] As an implementation manner, the adjusting component further includes a locking nut for locking the adjusting column. The adjusting column is threadedly connected to the locking nut.
[0046] As an implementation manner, spacers are provided between the first stator magnetic ring and the coil, between the coil and the second stator magnetic ring, between the first mover magnetic ring and the second mover magnetic ring, and between the second mover magnetic ring and the third mover magnetic ring. The spacers are annular. The spacers on the mover are made of non-magnetic materials and are used for positioning and supporting; the spacers on the stator are made of non-magnetic and insulating materials.
[0047] As an implementation manner, the inner walls of the first stator magnetic ring, the coil, and the second stator magnetic ring are flush, and the outer peripheries of the first mover magnetic ring, the second mover magnetic ring, and the third mover magnetic ring are flush.
[0048] As an implementation manner, gaps are left between the second mover magnetic ring and the coil, and between the adjusting magnetic ring and the inner wall of the mover body to facilitate the lifting of the mover assembly and the adjusting column.
[0049] The utility model utilizes the magnetic levitation force generated between the magnetic rings arranged in a certain configuration to compensate or offset the load gravity, so as to achieve precise positioning and vibration isolation within a certain stroke. It has the characteristics of no contact friction, large static force, adjustable static force, small static force fluctuation, and can provide dynamic force to compensate the static force.
[0050] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalent scope.
Claims
1. A magnetic levitation gravity balancer, comprising a stator assembly, a rotor assembly, and an adjustment assembly. The stator assembly includes a stator body, and the rotor assembly includes a rotor body. The rotor body is disposed on the stator body, and the rotor body is hollow. It is characterized in that, Inside the stator body, a first stator magnetic ring, a coil, and a second stator magnetic ring are sequentially arranged from top to bottom. On the outer periphery of the rotor body, a first rotor magnetic ring, a second rotor magnetic ring, and a third rotor magnetic ring are sequentially arranged from top to bottom. The adjusting assembly includes an adjusting column, the upper end of the adjusting column is located inside the rotor body, and an adjusting magnetic ring is arranged on the outer periphery of the upper end of the adjusting column. The magnetization directions of the first stator magnetic ring, the second stator magnetic ring, and the second rotor magnetic ring are radial, and the magnetization directions of the first rotor magnetic ring, the third rotor magnetic ring, and the adjusting magnetic ring are axial.
2. The magnetic levitation gravity balancer according to claim 1, wherein, The magnetic field directions of the first stator magnetic ring and the second rotor magnetic ring are the same, and the magnetic field directions of the first stator magnetic ring and the second stator magnetic ring are opposite; the magnetic field directions of the third rotor magnetic ring and the first rotor magnetic ring are opposite, and the magnetic field directions of the third rotor magnetic ring and the adjusting magnetic ring are the same.
3. The magnetic levitation gravity balancer according to claim 1, characterized in that, The stator body is provided with a water inlet and a water outlet, and a water channel is arranged inside the stator body corresponding to the coil, and the head and tail ends of the water channel are respectively communicated with the water inlet and the water outlet.
4. The magnetic levitation gravity balancer according to claim 3, characterized in that, The water channel is spiral or cylindrical.
5. The magnetic levitation gravity balancer according to claim 1, characterized in that, The adjusting assembly further includes a locking nut for locking the adjusting column, and the adjusting column is threadedly connected with the locking nut.
6. The magnetic levitation gravity balancer according to claim 1, wherein, Spacers are arranged between the first stator magnetic ring and the coil, between the coil and the second stator magnetic ring, between the first rotor magnetic ring and the second rotor magnetic ring, and between the second rotor magnetic ring and the third rotor magnetic ring.
7. The magnetic levitation gravity balancer according to claim 1, characterized in that, The inner walls of the first stator magnetic ring, the coil, and the second stator magnetic ring are flush, and the outer peripheries of the first rotor magnetic ring, the second rotor magnetic ring, and the third rotor magnetic ring are flush.
8. The magnetic levitation gravity balancer according to claim 7, wherein A gap is left between the second rotor magnetic ring and the coil, and between the adjusting magnetic ring and the inner wall of the rotor body.
9. The magnetic levitation gravity balancer according to claim 1, wherein The adjusting column is threadedly connected with the bottom of the stator body.