Ultra-precision air-floating linear motor module
Patent Information
- Application Number
- CN202521659750.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-05
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-08-05
AI Technical Summary
[0002]直线电机是一种将电能直接转换成直线运动机械能，而不需要任何中间转换机构的传动装置，它可以看成是一台旋转电机按径向剖开，并展成平面而成，市场上直线电机本体一般采用铝挤型型材结构作为本体，铝挤型型材滑动座作为承载结构，滑动座与滚动导轨之间直接接触，两者间的摩擦力就大，直线电机模组是高端装备制造的常用输送部件，广泛应用于半导体光刻机、晶圆检测设备等超精密场景，这些领域要求运动平台（即，滑动座）具备高定位精度、高速稳定性及抗微振动能力，传统滚动导轨与运动平台（即，滑动座）因颗粒磨损和摩擦波动难以满足需求
该超精密气浮直线电机模组通过滑动机构与定子组件之间的连接，滑动机构可以在定子组件上沿第一方向往复滑动，且滑动机构与定子组件之间形成有间隙，通过气浮机构向间隙内输送压缩气体可以使间隙中有气流游走而形成气膜，使滑块机构与定子组件之间就没有直接接触，通过气膜的作用，可以减少滑动机构与定子组件之间的摩擦力，使得滑块机构往复滑动平滑，速度波动小，适合需要超稳速的应用场景，通过滑动机构与定子组件形成的阶梯状间隙（即，滑动机构端部与定子组件之间间隙＜滑动机构中部与定子组件之间间隙），气膜形成高压核心区以及高阻尼边缘区，即，在不改变压缩气源的功率情况下，滑动机构中部能够提供稳定的高压气体量，滑动机构端部能够增大气体逸出阻力，抑制压力泄漏，减少微振与速度纹波，同等的供气量，能够提高气膜刚度，以使气膜的承载力提升，进而保证滑动机构往复滑动的稳定性，在不增加能耗的情况下（即，不改变压缩气源的功率），能够提高气膜的稳定性。
Smart Images
Figure CN224909343U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of linear motor technology, specifically to an ultra-precision air-bearing linear motor module. Background Technology
[0002] A linear motor is a transmission device that directly converts electrical energy into linear motion mechanical energy without any intermediate conversion mechanism. It can be viewed as a rotary motor cut radially and unfolded into a plane. In the market, the body of a linear motor is generally made of aluminum extruded profile as the body and aluminum extruded profile sliding seat as the load-bearing structure. The sliding seat and the rolling guide are in direct contact, resulting in high friction between them. Linear motor modules are commonly used conveying components in high-end equipment manufacturing and are widely used in ultra-precision scenarios such as semiconductor lithography machines and wafer inspection equipment. These fields require the motion platform (i.e., the sliding seat) to have high positioning accuracy, high-speed stability, and resistance to micro-vibration. Traditional rolling guides and motion platforms (i.e., sliding seats) cannot meet the requirements due to particle wear and friction fluctuations.
[0003] The industry commonly uses "air-bearing linear motor modules," which utilize air bearings to achieve contactless support and are driven by linear motors. This enables the sliding mechanism (mover) to achieve highly dynamic and smooth linear motion on the stator assembly. Existing air-bearing linear motor modules typically employ a structure where the mover is slidably connected to the stator via a linear groove. A uniform gap is formed between the groove and the stator, and air film is formed by supplying air through uniformly distributed air holes. However, because the gap size remains consistent along the entire length, the uniform gap results in excessively low resistance to gas escape at the edges, leading to excessive gas leakage and reduced air film stiffness. When the equipment's operating acceleration increases or the load increases, the air film pressure decreases, which can easily cause instability in the sliding mechanism (mover) position. This forces the system to slow down, thus restricting production efficiency and conveying accuracy. Increasing the power of the compressed gas supplied to the air holes will increase energy consumption, making it difficult to simultaneously consider the air film's load-bearing capacity and stability under a given air supply power (i.e., energy consumption). Summary of the Invention
[0004] This invention provides an ultra-precision air-bearing linear motor module, which solves the problems mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: Design an ultra-precision air-bearing linear motor module, including a stator assembly and a mover assembly; The moving part assembly includes an air flotation mechanism and a sliding mechanism. The sliding mechanism is slidably connected to the stator assembly along a first direction, and a gap is formed between the sliding mechanism and the stator assembly. The gap between the end of the sliding mechanism along the first direction and the stator assembly is smaller than the gap between the middle part of the sliding mechanism along the first direction and the stator assembly. The air flotation mechanism is disposed on the sliding mechanism and is used to deliver compressed gas into the gap.
[0006] Optionally, the air flotation mechanism includes an air inlet and an air outlet formed on the sliding mechanism. The input end of the air inlet is connected to a compressed air source, the input end of the air outlet is connected to the output end of the air inlet, and the output end of the air outlet faces the stator assembly.
[0007] Optionally, the sliding mechanism includes a slider and a motor mover. The motor mover is disposed inside the slider. The slider is slidably connected to the stator assembly along a first direction through a groove. The air inlet and air outlet are both opened on the slider. An air passage for connecting the air inlet and air outlet is opened inside the slider.
[0008] Optionally, the slider includes a first segment and two second segments, wherein one second segment is fixedly connected to one end of the first segment along a first direction, and the other second segment is fixedly connected to the other end of the first segment along the first direction, and the gap between the second segment and the stator assembly is smaller than the gap between the first segment and the stator assembly.
[0009] Optionally, the air outlet includes a plurality of first air holes and second air holes, wherein the plurality of first air holes are evenly distributed on the first section and the plurality of second air holes are evenly distributed on two second sections.
[0010] Optionally, the diameter of the second air outlet is smaller than the diameter of the first air outlet, and the outlets of both the second and first air outlets face the stator assembly.
[0011] Optionally, the stator assembly includes a base mechanism and a platform mechanism. The platform mechanism includes a motor stator and a guide rail. The slider is slidably connected to the guide rail through an opening groove. The motor stator is laid on the surface of the guide rail along a first direction and is at least partially located in the groove. The output ends of the second air hole and the first air hole both face the guide rail.
[0012] This utility model provides an ultra-precision air-bearing linear motor module, which has the following advantages: This ultra-precision air-bearing linear motor module connects to the stator assembly via a sliding mechanism. The sliding mechanism can reciprocate along a first direction on the stator assembly, and a gap is formed between the sliding mechanism and the stator assembly. Compressed gas is supplied into this gap via the air-bearing mechanism, causing airflow to form an air film. This eliminates direct contact between the sliding mechanism and the stator assembly. The air film reduces friction between them, resulting in smooth reciprocating motion with minimal speed fluctuations, making it suitable for applications requiring ultra-stable speed. The stepped gap formed between the sliding mechanism and the stator assembly (…) That is, the gap between the end of the sliding mechanism and the stator assembly is less than the gap between the middle of the sliding mechanism and the stator assembly. The air film forms a high-pressure core area and a high-damping edge area. In other words, without changing the power of the compressed air source, the middle of the sliding mechanism can provide a stable amount of high-pressure gas, and the end of the sliding mechanism can increase the gas escape resistance, suppress pressure leakage, and reduce micro-vibration and velocity ripple. With the same amount of air supply, the stiffness of the air film can be improved, so as to improve the load-bearing capacity of the air film and thus ensure the stability of the reciprocating sliding of the sliding mechanism. Without increasing energy consumption (i.e., without changing the power of the compressed air source), the stability of the air film can be improved. Attached Figure Description
[0013] Figure 1 This is a three-dimensional structural diagram of the ultra-precision air-bearing linear motor module of this utility model; Figure 2 This is a schematic diagram of the installation structure of the ultra-precision air-bearing linear motor module of this utility model; Figure 3 This is a front view cross-sectional structural diagram of the slider in this utility model; Figure 4 This is a top view cross-sectional structural diagram of the slider in this utility model.
[0014] In the diagram: 10, stator assembly; 11, base mechanism; 12, platform mechanism; 121, guide rail; 122, motor stator; 20, mover assembly; 21, air flotation mechanism; 211, air inlet; 212, air outlet; 2121, first air hole; 2122, second air hole; 22, sliding mechanism; 221, slider; 31, first gap; 32, second gap. Detailed Implementation
[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.
[0016] Please see Figures 1 to 4This utility model provides a technical solution: a linear motor module, more specifically an air-bearing linear motor module with an air-bearing design, for precision conveying, such as the conveying of wafers or chips, which can ensure the rigidity of the air film, improve the conveying load-bearing capacity, and avoid increasing the consumption of airflow.
[0017] Please see Figures 1 to 4 The present invention provides a technical solution: an ultra-precision air-bearing linear motor module, comprising a stator assembly 10 and a mover assembly 20; The mover assembly 20 includes an air flotation mechanism 21 and a sliding mechanism 22. The sliding mechanism 22 is slidably connected to the stator assembly 10 along a first direction, and a gap is formed between the sliding mechanism 22 and the stator assembly 10. The gap between the end of the sliding mechanism 22 along the first direction and the stator assembly 10 is smaller than the gap between the middle of the sliding mechanism 22 and the stator assembly 10 along the first direction. The air flotation mechanism 21 is disposed on the sliding mechanism 22 and is used to deliver compressed gas into the gap. The air flotation mechanism 21 delivers compressed gas into the gap, forming a dual-state flow field of a high-pressure core region and a high-damping edge region under the constraints of a narrow end gap (5-7 μm) and a wide middle gap (8-10 μm). The narrow end gap refers to... Yes, the gap between the two ends of the sliding mechanism 22 and the stator assembly 10, that is, the gap between the two ends of the sliding mechanism 22 is smaller than the gap in the middle, thus forming a stepped flow resistance channel of "narrow end - wide middle"; the air flotation mechanism 21 is embedded in the bottom surface of the sliding mechanism 22, and injects compressed air evenly into the entire gap. This geometric air supply coordination relationship allows the gas in the central area to accumulate rapidly under low flow resistance to form a high-pressure core area, and the end area generates a high-damping edge area due to the narrow gap, which not only suppresses the end pressure leakage but also automatically distributes the pressure, realizing a composite air film with high static stiffness, high load-bearing capacity and sufficient damping. Finally, the sliding mechanism 22 obtains a linear motion with low friction and low speed ripple in a non-contact state, improving positioning accuracy and avoiding additional energy consumption or temperature rise; Furthermore, it can be understood that the gap between the sliding mechanism 22 and the stator assembly 10 is set in a stepped shape or a sloping shape along the first direction.
[0018] Through the connection between the sliding mechanism 22 and the stator assembly 10, the sliding mechanism 22 can reciprocate along the first direction on the stator assembly 10, and a gap is formed between the sliding mechanism 22 and the stator assembly 10. By supplying compressed gas into the gap through the air flotation mechanism 21, airflow can be generated within the gap to form an air film, thus eliminating direct contact between the slider 221 mechanism and the stator assembly 10. The air film reduces the friction between the sliding mechanism 22 and the stator assembly 10, resulting in smooth reciprocating sliding of the slider 221 mechanism with minimal speed fluctuation, suitable for applications requiring ultra-stable speed. The stepped gap formed between the sliding mechanism 22 and the stator assembly 10 further enhances this effect. The gap (i.e., the gap between the end of the sliding mechanism 22 and the stator assembly 10 is less than the gap between the middle of the sliding mechanism 22 and the stator assembly 10) forms a high-pressure core region and a high-damping edge region. That is, without changing the power of the compressed air source, the middle of the sliding mechanism 22 can provide a stable amount of high-pressure gas, and the end of the sliding mechanism 22 can increase the gas escape resistance, suppress pressure leakage, reduce micro-vibration and velocity ripple. With the same amount of air supply, the stiffness of the air film can be improved, so as to improve the load-bearing capacity of the air film, thereby ensuring the stability of the reciprocating sliding of the sliding mechanism 22. Without increasing energy consumption (i.e., without changing the power of the compressed air source), the stability of the air film can be improved.
[0019] In this embodiment, as a preferred option, the air flotation mechanism 21 includes an air inlet 211 and an air outlet 212 formed on the sliding mechanism 22. The input end of the air inlet 211 is connected to the compressed air source, the input end of the air outlet 212 is connected to the output end of the air inlet 211, and the output end of the air outlet 212 faces the stator assembly 10. The air inlet 211 is directly connected to a compressed air source, which is a known technology. The air pressure of the compressed air source is also a known technology. The air pressure can be controlled as needed. The air outlet 212 is turned vertically towards the surface corresponding to the stator assembly 10 after passing through the flow channel. The vertical airflow forms an aerodynamic vortex in the narrow gap area (i.e., the gap between the end of the sliding mechanism 22 and the stator assembly 10), which reduces the leakage of gas at the end of the sliding mechanism 22.
[0020] In this embodiment, as a preferred solution, the sliding mechanism 22 includes a slider 221 and a motor mover. The motor mover is disposed inside the slider 221. The slider 221 is slidably connected to the stator assembly 10 along the first direction through a groove. The air inlet 211 and the air outlet 212 are both opened on the slider 221. An air passage for connecting the air inlet 211 and the air outlet 212 is opened inside the slider 221. The motor mover is embedded in the slider 221. This is a known prior art. That is, the operation of the linear motor is a known prior art. The air passage is directly milled inside the slider 221, connecting the air inlet 211 and the air outlet 212 to form a closed air passage with zero external pipe passage. Alternatively, the slider 221 can be made by injection molding. The slider 221 is slidably connected to the stator assembly 10 through the groove. That is, the gap is the gap formed between the inner wall of the groove and the stator assembly 10 located inside the groove.
[0021] More specifically, the gaps include a first gap 31 formed between the inner wall of the slide groove and the stator assembly 10 along the second direction and a second gap 32 formed between the inner wall of the slide groove and the stator assembly 10 along the third direction. The first gap 31 is distributed in a stepped manner along the first direction, that is, the first gap 31 is narrow-wide-narrow along the first direction. The second gap 32 is distributed in a stepped manner along the first direction, that is, the second gap 32 is narrow-wide-narrow along the first direction.
[0022] In this embodiment, as a preferred solution, the slider 221 includes a first segment and two second segments. One second segment is fixedly connected to one end of the first segment along the first direction, and the other second segment is fixedly connected to the other end of the first segment along the first direction. The gap between the second segment and the stator assembly 10 is smaller than the gap between the first segment and the stator assembly 10. The two second segments are fixedly connected to both ends of the first segment along the first direction to form an "I-shaped" inner cavity. The wide gap between the first segment and the second segment can reduce turbulent kinetic energy, and the narrow gap between the second segment and the first segment increases the gas escape resistance, thereby improving the rigidity of the gas film. The gas supply flow is reduced under the same load, thereby reducing energy consumption. A flexible buffer layer, namely silicone rubber, can also be provided between the first segment and the second segment to absorb thermal deformation differences.
[0023] In this embodiment, as a preferred option, the air outlet 212 includes a plurality of first air outlets 2121 and second air outlets 2122. The plurality of first air outlets 2121 are evenly distributed on the first section, and the plurality of second air outlets 2122 are evenly distributed on the two second sections.
[0024] In this embodiment, as a preferred option, the diameter of the output end of the second vent 2122 is smaller than the diameter of the output end of the first vent 2121, and the output ends of both the second vent 2122 and the first vent 2121 face the stator assembly 10. The first vent 2121 is evenly distributed in the first section (i.e., the wide gap region), and the second vent 2122 is evenly distributed in the second section (i.e., the narrow gap region). All the first vents 2121 and the second vent 2122 are sprayed perpendicularly to the surface of the stator assembly 10. The large diameter of the first vent 2121 can quickly fill the wide gap region and improve the pressure build-up speed. The small diameter of the second vent 2122 forms a high-speed shear layer in the narrow gap region, generating a vortex to lock in gas leakage. Furthermore, the uniform distribution of multiple first air holes 2121 and second air holes 2122 means that multiple first air holes 2121 and second air holes 2122 are circumferentially distributed on the inner wall of the chute to form a group, and multiple groups of first air holes 2121 and second air holes 2122 are arranged sequentially along the first direction.
[0025] In this embodiment, as a preferred solution, the stator assembly 10 includes a base mechanism 11 and a platform mechanism 12. The platform mechanism 12 includes a motor stator 122 and a guide rail 121. The slider 221 is slidably connected to the guide rail 121 through a groove. The motor stator 122 is laid on the surface of the guide rail 121 along a first direction and is at least partially located in the groove. The output ends of the second air hole 2122 and the first air hole 2121 both face the guide rail 121. The base mechanism 11 and the platform mechanism 12 are both existing known technologies and are only referenced here without further explanation. The purpose is that the base mechanism 11 is used to support the guide rail 121, and the motor stator... The stator 122 is arranged in a straight line and fixedly installed on the guide rail 121. The stator 122 can be fixedly connected to the guide rail 121 by bolts. When the slider 221 is slidably connected to the guide rail 121, at least part of the stator 122 is also located in the groove. As the slider 221 slides on the guide rail 121, the part of the stator 122 located in the groove also changes accordingly, corresponding to the position of the slider 221. The stator 122 cooperates with the motor mover located in the slider 221 to drive the slider 221 to slide along the guide rail 121. The cooperation between the stator 122 and the motor mover is a known technology and will not be described in detail here.
[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An ultra-precision air-bearing linear motor module, characterized in that: It includes a stator assembly (10) and a mover assembly (20); The moving part assembly (20) includes an air flotation mechanism (21) and a sliding mechanism (22). The sliding mechanism (22) is slidably connected to the stator assembly (10) along a first direction, and a gap is formed between the sliding mechanism (22) and the stator assembly (10). The gap between the end of the sliding mechanism (22) along the first direction and the stator assembly (10) is smaller than the gap between the middle part of the sliding mechanism (22) along the first direction and the stator assembly (10). The air flotation mechanism (21) is disposed on the sliding mechanism (22) and is used to deliver compressed gas into the gap.
2. The ultra-precision air-bearing linear motor module according to claim 1, characterized in that: The air flotation mechanism (21) includes an air inlet (211) and an air outlet (212) formed on the sliding mechanism (22). The input end of the air inlet (211) is connected to a compressed air source, and the input end of the air outlet (212) is connected to the output end of the air inlet (211). The output end of the air outlet (212) faces the stator assembly (10).
3. The ultra-precision air-bearing linear motor module according to claim 2, characterized in that: The sliding mechanism (22) includes a slider (221) and a motor mover. The motor mover is disposed inside the slider (221). The slider (221) is slidably connected to the stator assembly (10) along the first direction through a groove. The air inlet (211) and the air outlet (212) are both opened on the slider (221). An air passage for connecting the air inlet (211) and the air outlet (212) is opened inside the slider (221).
4. The ultra-precision air-bearing linear motor module according to claim 3, characterized in that: The slider (221) includes a first segment and two second segments, wherein one second segment is fixedly connected to one end of the first segment along a first direction, and the other second segment is fixedly connected to the other end of the first segment along a first direction. The gap between the second segment and the stator assembly (10) is smaller than the gap between the first segment and the stator assembly (10).
5. The ultra-precision air-bearing linear motor module according to claim 4, characterized in that: The air outlet (212) includes a plurality of first air outlets (2121) and second air outlets (2122). The plurality of first air outlets (2121) are evenly distributed on the first section, and the plurality of second air outlets (2122) are evenly distributed on the two second sections.
6. The ultra-precision air-bearing linear motor module according to claim 5, characterized in that: The diameter of the output end of the second vent (2122) is smaller than the diameter of the output end of the first vent (2121), and the output ends of the second vent (2122) and the first vent (2121) are both oriented toward the stator assembly (10).
7. The ultra-precision air-bearing linear motor module according to claim 5, characterized in that: The stator assembly (10) includes a base mechanism (11) and a platform mechanism (12). The platform mechanism (12) includes a motor stator (122) and a guide rail (121). The slider (221) is slidably connected to the guide rail (121) through an opening groove. The motor stator (122) is laid on the surface of the guide rail (121) along a first direction and is at least partially located in the groove. The output ends of the second air hole (2122) and the first air hole (2121) both face the guide rail (121).