Vacuum chamber through-wall multi-degree-of-freedom robot

Abstract

This invention relates to the field of vacuum transmission and sealing technology, specifically a multi-degree-of-freedom manipulator that penetrates the wall of a vacuum chamber, comprising a base flange, a linear drive rod, a welded bellows, a first coupling, and a second coupling. The base flange is installed on the outer wall of the vacuum chamber; the linear drive rod extends into the vacuum chamber through the base flange; the welded bellows is sleeved around the linear drive rod, with its fixed end sealed to the base flange; the first coupling is sealed and fitted around the outer circumference of the linear drive rod; the second coupling radially moves with the first coupling and is sealed to the moving end of the welded bellows, with its inner diameter larger than the diameter of the linear drive rod, forming a radial clearance. This invention eliminates the radial runout of the welded bellows through the radially moving fit between the first and second couplings, preventing it from interfering with the motion accuracy of the linear drive rod and simultaneously improving the fatigue life of the bellows.

Description

Technical Field

[0001] This invention relates to the field of vacuum isothermal forging equipment technology, specifically to a multi-degree-of-freedom manipulator that penetrates the walls of a vacuum chamber. Background Technology

[0002] In high-end manufacturing scenarios such as vacuum isothermal forging and semiconductor coating, robotic arms need to penetrate the outer wall of a vacuum chamber to operate inside. The linear through-wall transmission mechanism must accurately transmit the axial motion of the atmospheric-side drive source to the inside of the vacuum chamber while ensuring a vacuum seal. These scenarios place stringent requirements on the repeatability, sealing reliability, and continuous service life of the transmission mechanism.

[0003] In addressing vacuum linear through-wall sealing issues, welded bellows are commonly used as axially flexible sealing elements. The conventional approach is to rigidly connect the drive rod directly to the moving end of the bellows, allowing the bellows to expand and contract synchronously with the drive rod to maintain the integrity of the seal and ensure direct transmission of axial force. The underlying engineering design principle is that only a rigid connection can simultaneously guarantee lossless transmission of axial force and the integrity of the seal; any form of flexible connection will damage the sealing interface or introduce axial clearance, thereby reducing transmission accuracy and sealing reliability.

[0004] However, the aforementioned rigid connection scheme has inherent physical contradictions. During the reciprocating expansion and contraction of the bellows, due to factors such as corrugated plate processing errors, assembly deviations, and thermal deformation, the moving end of the bellows will generate inherent radial runout. Since the transmission rod is rigidly connected to the moving end of the bellows, this radial runout is directly transmitted to the transmission rod, resulting in a decrease in the positioning accuracy of the transmission rod end. At the same time, the lateral reaction force on the transmission rod will also act in the opposite direction on the bellows, causing the bellows to be subjected to alternating radial bending stress for a long time, significantly limiting its fatigue life and making it difficult to meet the reliability requirements of continuous industrial production. If a buffer structure is added to extend the service life, sliding or clearance fits must be introduced at the sealing boundary, increasing the risk of vacuum leakage, and the buffer element itself may introduce axial clearance, further reducing transmission accuracy.

[0005] In summary, existing solutions consistently fail to balance transmission accuracy, sealing reliability, and bellows fatigue life, stemming from the bidirectional coupling of radial forces caused by rigid connections. Overcoming this inherent physical contradiction has become a pressing technical challenge in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-degree-of-freedom manipulator for vacuum cavity wall penetration, so as to solve the problem that the transmission accuracy, sealing reliability and bellows fatigue life cannot be simultaneously achieved in the vacuum wall penetration transmission scenario of the prior art.

[0007] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: This invention provides a multi-degree-of-freedom manipulator that penetrates the wall of a vacuum cavity, comprising: a base flange for mounting on the wall of a vacuum cavity, such that two sides of the base flange face the atmospheric side and the interior of the vacuum cavity, respectively; a linear drive rod penetrating the base flange, one end of which is connected to a drive mechanism on the atmospheric side, and the other end extending into the interior of the vacuum cavity to transmit linear drive from the atmospheric side to the interior of the vacuum cavity; a welded bellows sleeved around the linear drive rod, its fixed end sealed and fixed to the vacuum side surface of the base flange; a first sleeve axially fixed and sealed to the outer peripheral surface of the linear drive rod; a second sleeve fixed and sealed to the moving end of the welded bellows; the first sleeve and the second sleeve... The two connecting parts are axially linked so that the axial movement of the linear transmission rod is transmitted to the moving end of the welded bellows via the first and second connecting parts, causing the moving end to extend and retract synchronously. The inner diameter of the second connecting part is larger than the outer diameter of the linear transmission rod to form a radial gap, which provides space for the radial runout of the moving end. The first and second connecting parts can float radially relative to each other to block the transmission of the radial runout to the first connecting part and the linear transmission rod. The internal channels of the first and second connecting parts, the internal space of the welded bellows, and the base flange together enclose and define an internal space that is isolated from the interior of the vacuum chamber.

[0008] According to one embodiment of the present invention, the first socket and the second socket are connected by an elastic coupling, wherein a first end of the elastic coupling is fixedly connected to the first socket and a second end is fixedly connected to the second socket, and the elastic body inside the elastic coupling allows the first end and the second end to float radially relative to each other, so as to realize the radial relative floating between the first socket and the second socket.

[0009] According to one embodiment of the present invention, a plurality of radial elastic support plates are uniformly arranged circumferentially between the moving end and the fixed end of the welded bellows. One end of each elastic support plate is fixed to the moving end of the welded bellows, and the other end is fixed to the vacuum side surface of the base flange. The radial stiffness of the elastic support plate is 5 to 10 times that of the radial stiffness of the welded bellows, and the axial stiffness is 1 / 10 to 1 / 5 that of the axial stiffness of the welded bellows.

[0010] According to one embodiment of the present invention, it further includes at least one guide rod, the guide rod being fixed to the vacuum side surface of the base flange; a slider is fixed on the linear transmission rod, the slider being slidably engaged with the guide rod.

[0011] According to one embodiment of the present invention, the guide rods are in two sets, symmetrically arranged on both sides of the welded bellows, so that the guiding constraint forces on both sides of the linear transmission rod during axial movement are balanced.

[0012] According to one embodiment of the present invention, it further includes a fixed heat insulation screen and a follower heat insulation cover; the fixed heat insulation screen is fixed to the vacuum side surface of the base flange, and the follower heat insulation cover is fixed to the linear transmission rod and moves synchronously with it; the fixed heat insulation screen and the follower heat insulation cover maintain partial overlap within the range of motion of the linear transmission rod to block heat radiation from inside the vacuum cavity.

[0013] According to one embodiment of the present invention, the fixed heat insulation screen extends a first sleeve structure to the follower heat insulation cover, and the follower heat insulation cover extends a second sleeve structure to the fixed heat insulation screen; the first sleeve structure and the second sleeve structure are nested around the periphery of the linear transmission rod, and a labyrinthine gap channel is formed between them.

[0014] According to one embodiment of the present invention, the first sleeve structure and the second sleeve structure on the periphery of the linear transmission rod have rolled edges at their opposite edges, and there is an axial gap between them along the axial direction, the distance of which is adapted to the stroke of the linear transmission rod.

[0015] According to one embodiment of the invention, it further includes at least one rotary transmission rod that passes through the base flange and rotates about its own axis to provide R-axis transmission; a magnetohydrodynamic sealing assembly is provided between the rotary transmission rod and the base flange.

[0016] According to one embodiment of the present invention, a plurality of linear transmission rods and a plurality of rotary transmission rods are included, respectively corresponding to at least one of the X-axis, Y-axis, Z-axis and R-axis of the manipulator. The present invention also provides a motion; a cooling medium flow channel is provided inside the base flange, and the cooling medium flow channel extends to the housing of the magnetohydrodynamic sealing assembly.

[0017] Compared with the prior art, the present invention has the following advantages: This invention differs from the conventional approach of "rigidly connecting the transmission rod to the moving end of the bellows" in existing technologies. By setting a first and a second coupling between the transmission rod and the moving end of the bellows, the transmission chain is reconstructed into two independent paths: axial force transmission and radial decoupling. Specifically, the sealing connection between the first coupling and the transmission rod ensures the transmission of axial force; the radial movement between the second coupling and the first coupling, and the radial clearance reserved between the inner hole of the second coupling and the transmission rod, prevents the inherent radial runout of the bellows' moving end from being transmitted to the transmission rod at the second coupling; and the sealing structure formed by the first coupling, the second coupling, and the welded bellows maintains the isolation between the vacuum chamber and the atmosphere. Thus, while maintaining transmission accuracy and isolation reliability, the fatigue life of the bellows is improved, meeting the practical application requirements of vacuum wall-penetrating manipulator structures. Attached Figure Description

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of this application.

[0020] Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle.

[0021] Figure 3 for Figure 1 The enlarged view at point B shows the rolled edge structure and axial gap.

[0022] The reference numerals in the figure are as follows: 100. Vacuum chamber; 200. Base flange; 300. Welded bellows; 400. Linear drive rod; 410. Slider; 510. First sleeve; 520. Second sleeve; 521. Radial clearance; 600. Guide rod; 700. Rotary drive rod; 710. Magnetohydrodynamic sealing assembly; 800. Heat insulation screen; 810. First sleeve structure; 900. Follow-up heat insulation cover; 910. Second sleeve structure; 920. Rolled edge structure; 930. Axial clearance. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] like Figure 1 and Figure 2 As shown, this embodiment provides a multi-degree-of-freedom manipulator that penetrates the wall of a vacuum cavity, comprising: A base flange 200 is used to be installed on the wall of the vacuum chamber 100, such that the two sides of the base flange 200 face the atmosphere and the interior of the vacuum chamber 100, respectively.

[0025] A linear drive rod 400 passes through a hole in the base flange 200. One end of the rod is used to connect to the drive mechanism on the atmospheric side, and the other end extends into the vacuum chamber 100 to transmit the linear drive from the atmospheric side to the vacuum chamber 100.

[0026] A welded bellows 300 is sleeved around the linear transmission rod 400, and its fixed end is sealed and fixed to the vacuum side surface of the base flange 200.

[0027] A first coupling 510 is axially fixed and sealed to the outer circumferential surface of the linear transmission rod 400.

[0028] A second coupling 520 is fixedly and sealingly connected to the moving end of the welded bellows 300. The first coupling 510 and the second coupling 520 are axially linked, so that the axial movement of the linear transmission rod 400 is transmitted to the moving end of the welded bellows 300 via the first coupling 510 and the second coupling 520, causing the moving end to extend and retract synchronously. The inner diameter of the second coupling 520 is larger than the outer diameter of the linear transmission rod 400, forming a radial gap 521, which provides space for the radial runout of the moving end. The first coupling 510 and the second coupling 520 can float radially relative to each other to block the transmission of radial runout to the first coupling 510 and the linear transmission rod 400.

[0029] The internal channels of the first set of connectors 510 and the second set of connectors 520, the internal space of the welded bellows 300, and the base flange 200 together enclose and define an internal space that is isolated from the interior of the vacuum chamber 100. This internal space is an independent area completely isolated from the vacuum chamber 100, used to accommodate the movement of the linear drive rod 400 and ensure that the vacuum level of the vacuum chamber 100 is not affected by the external environment.

[0030] During operation, an external drive source propels the linear transmission rod 400 in an axial feed motion. The transmission rod drives the first coupling 510, which is axially fixed to it, to move axially synchronously. The first coupling 510 and the second coupling 520 are axially linked, transmitting axial force to the moving end of the bellows, which is fixedly connected to the second coupling 520, causing the bellows to extend and retract accordingly. At the same time, the inherent radial runout generated at the moving end of the bellows is directly transmitted to the second coupling 520 fixed to it. Because there is a radial clearance 521 between the inner hole of the second coupling 520 and the transmission rod, and because the first coupling 510 and the second coupling 520 can float radially relative to each other, this radial runout is effectively blocked at the second coupling 520 and will not be further transmitted to the first coupling 510 and the transmission rod. Throughout the entire movement, the internal space enclosed by all components remains isolated from the interior of the vacuum chamber 100.

[0031] This embodiment achieves separation of axial force transmission and radial decoupling by setting a first coupling 510 and a second coupling 520 between the transmission rod and the moving end of the bellows, and designing them to be axially linked and radially floating relative to each other, while reserving a radial gap 521. Thus, while maintaining transmission accuracy and sealing reliability, the fatigue life of the bellows is improved, thereby meeting the requirements of the robot arm in a vacuum environment.

[0032] While the aforementioned scheme has achieved decoupling between axial force transmission and radial force transmission, practical applications present challenges in selecting the appropriate radial floating connection structure and controlling its cost. To address these issues, this embodiment proposes the following design.

[0033] In this embodiment, the first coupling 510 and the second coupling 520 are connected by an elastic coupling. The first end of the elastic coupling is fixedly connected to the first coupling 510, and the second end is fixedly connected to the second coupling 520. The elastic body inside the elastic coupling allows the first end and the second end to float radially relative to each other, thereby achieving radial relative floating between the first coupling 510 and the second coupling 520.

[0034] Flexible couplings are a mature, commercially available standard component. Their internal elastic body exhibits rigidity when transmitting axial force, and undergoes shear or compression deformation when subjected to radial displacement, thereby ensuring the transmission of axial force while absorbing radial runout.

[0035] When the transmission rod moves axially, the axial force is transmitted to the second coupling 520 via the first coupling 510 and the flexible coupling. When the bellows moving end generates radial runout, the runout is transmitted to the second coupling 520. The elastic body inside the flexible coupling deforms and absorbs the radial displacement, thus blocking the runout and preventing it from being transmitted to the first coupling 510 and the transmission rod.

[0036] The first coupling 510 and the second coupling 520 are directly connected by a flexible coupling. While achieving the radial floating function, the mature commercially available standard parts are used, which simplifies the assembly and debugging process of the device and reduces the manufacturing cost.

[0037] In a preferred embodiment, to resolve the technical contradiction between the radial runout absorption capacity and fatigue life of the welded bellows, a plurality of radial elastic support plates are uniformly arranged circumferentially between the moving end and the fixed end of the welded bellows 300.

[0038] The radial elastic support plates are made of 0.2~0.5mm thick 316L stainless steel or beryllium bronze sheets, and there are 4~8 pieces in total, which are evenly distributed at equal angles along the circumference of the welded bellows 300. One end of the elastic support plate is fixed to the moving end face of the welded bellows 300 by vacuum welding, and the other end is fixed to the vacuum side surface of the base flange 200 by bolts.

[0039] The radial stiffness of the elastic support plate is designed to be 5 to 10 times that of the welded bellows 300, and the axial stiffness is designed to be 1 / 10 to 1 / 5 of the axial stiffness of the welded bellows 300. This stiffness matching relationship ensures that when the moving end of the welded bellows 300 experiences radial runout, the radial force is entirely borne by the elastic support plate with high radial stiffness, and the welded bellows 300 only bears pure axial expansion and contraction force, completely eliminating radial bending deformation of the bellows. At the same time, the low axial stiffness of the elastic support plate will not generate significant resistance to the axial movement of the bellows, and the transmission efficiency loss is less than 5%.

[0040] This embodiment increases the fatigue life of the welded bellows from 1×10⁻⁶ days by adding radial elastic support plates, without changing the original floating connection structure or affecting the radial runout absorption capacity. 5 The next cycle is increased to 3×10 5 This ensures both reliable sealing and smooth operation.

[0041] While the aforementioned scheme has achieved axial force transmission and radial decoupling, in practical applications, there is a problem of insufficient linearity of motion due to cantilevered forces or lateral loads on the transmission rod. To address this issue, this embodiment proposes the following design.

[0042] This embodiment also includes at least one guide rod 600, which is fixed to the vacuum side surface of the base flange 200. A slider 410 is fixed on the linear drive rod 400, and the slider 410 is in sliding engagement with the guide rod 600.

[0043] Guide rod 600 refers to a smooth cylindrical guide rail whose extension direction is strictly parallel to the axis of linear transmission rod 400. Slider 410 refers to a sliding component fixed to the outer periphery of the transmission rod, which contains a linear bearing or sliding bushing, forming a low-friction sliding fit with guide rod 600. The extension direction of guide rod 600 is parallel to the axis of the transmission rod, providing lateral constraint for the axial movement of the transmission rod.

[0044] When the transmission rod moves axially, the slider 410 fixed on the transmission rod slides synchronously along the guide rod 600. The guide rod 600 constrains the position of the transmission rod in the plane perpendicular to the axial direction through the slider 410, preventing it from swaying or twisting due to uneven force, and ensuring that the movement of the transmission rod is strictly along the predetermined axis.

[0045] By adding a guide rod 600 fixed to the flange and directly engaging with the transmission rod via the slider 410, a stable axial sliding constraint is provided for the transmission rod. Placing the guide reference on the temperature-stable flange side avoids the influence of thermal deformation inside the vacuum chamber 100 on the guiding accuracy, thus improving the positional accuracy and motion smoothness of the linear transmission.

[0046] While the aforementioned solution already provides axial sliding constraint by adding a guide rod 600, unilateral guidance may still generate off-center load moments under heavy load or long stroke conditions, causing the transmission rod to be subjected to additional bending stress. To address the above issues, this embodiment incorporates the following design.

[0047] In this embodiment, there are two sets of guide rods 600, which are symmetrically arranged on both sides of the welded bellows 300, so that the guide constraint forces on both sides of the linear transmission rod 400 during axial movement are balanced.

[0048] Two sets of guide rods 600 are evenly distributed on both sides of the bellows with the transmission rod axis as the center of symmetry in space, forming a symmetrical load-bearing structure. The distance between the axis of the guide rods 600 on both sides and the axis of the transmission rod is equal, and the installation accuracy is controlled within the preset tolerance range.

[0049] When the transmission rod moves axially, the sliders 410 on both sides slide synchronously along their respective guide rods 600. Since the two sets of guide rods 600 are symmetrically arranged, the guiding reaction forces on both sides of the transmission rod at any position are equal in magnitude and opposite in direction, and the resultant force is zero.

[0050] The use of two sets of symmetrically arranged guide rods 600 ensures that the guiding constraint forces on both sides of the transmission rod are balanced during axial movement, eliminating the eccentric load torque that may be generated by unilateral guidance, and improving the load-bearing capacity and motion stability of the device under heavy load or long stroke conditions.

[0051] While the aforementioned solution has achieved decoupling of axial force transmission and radial force transmission, in high-temperature applications such as vacuum isothermal forging, the high temperature inside the vacuum chamber 100 can cause severe thermal effects on the transmission device and sealing interface through radiation, leading to problems such as aging of seals and changes in fit clearance. To address these issues, this embodiment incorporates the following design.

[0052] This embodiment also includes a fixed heat insulation screen 800 and a follower heat insulation cover 900. The fixed heat insulation screen 800 is fixed to the vacuum side surface of the base flange 200, and the follower heat insulation cover 900 is fixed to the linear transmission rod 400 and moves synchronously with it. The fixed heat insulation screen 800 and the follower heat insulation cover 900 maintain partial overlap within the range of motion of the linear transmission rod 400 to block heat radiation from inside the vacuum chamber 100.

[0053] The fixed heat shield 800 refers to a plate-shaped or cylindrical component fixedly installed on the vacuum side surface of the flange to block high-temperature radiation. The movable heat shield 900 refers to a cover structure fixedly installed on the transmission rod and moving synchronously with it. Both are made of high-temperature resistant, low-emissivity materials, such as molybdenum or tungsten sheets. The fixed heat shield 800 and the movable heat shield 900 have an initial overlap in the installed state, which is greater than the maximum stroke of the linear transmission rod 400 to ensure that they always maintain partial overlap throughout the entire stroke range.

[0054] During operation, the radiant heat from the high-temperature cavity first reaches the fixed heat shield 800, where most of it is reflected. As the drive rod moves axially, the follower heat shield 900 moves synchronously with it, always maintaining a partial overlap with the fixed heat shield 800, thus continuously blocking heat radiation from reaching the flange and sealing interface throughout the entire stroke of the drive rod.

[0055] By setting a fixed heat insulation screen 800 and a follow-up heat insulation cover 900, and maintaining partial overlap between the two throughout the entire stroke range, the high temperature inside the vacuum chamber 100 effectively blocks the heat radiation to the transmission device and sealing interface, reducing the risk of thermal deformation and sealing failure.

[0056] like Figure 3 As shown, based on the basic thermal protection achieved by the aforementioned solution through the fixed heat insulation screen 800 and the follow-up heat insulation cover 900, in order to further improve the thermal barrier effect, it is necessary to optimize the structure of the heat insulation screen 800. To address the above issues, this embodiment has the following design.

[0057] In this embodiment, a first sleeve structure 810 extends from the fixed heat insulation screen 800 to the follower heat insulation cover 900, and a second sleeve structure 910 extends from the fixed heat insulation screen 800. The first sleeve structure 810 and the second sleeve structure 910 are nested around the linear transmission rod 400, forming a labyrinthine gap channel between them.

[0058] The first sleeve structure 810 refers to an annular thin wall extending from the fixed heat insulation screen 800 towards the moving heat insulation cover 900, and the second sleeve structure 910 refers to an annular thin wall extending from the moving heat insulation cover 900 towards the fixed heat insulation screen 800. The two are nested together but do not contact each other. In this embodiment, the radial gap 521 between the first sleeve structure 810 and the second sleeve structure 910 is 0.5 mm to 2 mm, and the axial overlap length is 20 mm to 50 mm, so as to form an effective labyrinthine heat barrier channel.

[0059] When radiant heat passes through the labyrinthine gap channel formed between the first sleeve structure 810 and the second sleeve structure 910, it needs to undergo multiple reflections and absorptions, and the energy is gradually attenuated. In the end, only a very small amount of heat reaches the base flange 200 and the sealing interface.

[0060] The nested sleeve structure forms a labyrinthine gap channel, which significantly increases the heat radiation transmission path and attenuation times without contacting or affecting the movement of the transmission rod, thereby improving the thermal protection effect on the flange and sealing interface.

[0061] Based on the aforementioned scheme that forms a labyrinthine channel through nested sleeves, during the long stroke of the linear transmission rod 400, the nesting depth of the sleeve structure will change with the stroke. If sufficient axial clearance 930 is not reserved, the two sleeve structures may detach or mechanically interfere at the end of the stroke. To address the above problems, this embodiment has the following design.

[0062] In this embodiment, the first sleeve structure 810 and the second sleeve structure 910 on the periphery of the linear transmission rod 400 have rolled edge structures 920 at their opposite edges, and there is an axial gap 930 between them along the axial direction. The distance of the axial gap 930 is adapted to the stroke of the linear transmission rod 400.

[0063] The rolled edge structure 920 refers to bending or folding the thin-walled edge of the sleeve to form a smooth transition edge. The rolled edge structure 920 can be a 90-degree bend, an arc bend, or a wavy rolled edge, as long as the edge is smooth without sharp corners, preventing scratches and enhancing structural rigidity. The axial clearance 930 ensures that the two sleeve structures are always in a partially nested state throughout the entire stroke of the drive rod. Specifically, the axial clearance 930 is not less than the maximum stroke of the linear drive rod 400.

[0064] When the transmission rod performs a large-stroke axial movement, the follower heat shield 900 fixed to the transmission rod moves accordingly, causing the second sleeve structure 910 to slide inside the first sleeve structure 810. Because an axial clearance 930 adapted to the transmission rod's stroke is reserved between them, the second sleeve structure 910 will not completely detach from the first sleeve structure 810 during movement, always maintaining an effective labyrinthine nesting state. The rolled edge structure 920 prevents mechanical contact and scratching in extreme positions or with slight deviations.

[0065] By setting the rolled edge structure 920 and the axial clearance 930 adapted to the stroke, the labyrinth channel of the linear transmission rod 400 is always effectively nested throughout the entire stroke range, eliminating the risk of thermal shielding failure or mechanical interference that may be caused by long stroke movement.

[0066] Based on the aforementioned solution that provides a complete linear transmission sealing solution, actual multi-degree-of-freedom manipulators need to simultaneously possess rotary transmission capabilities, and the rotary seal and linear seal need to be integrated on the same mounting interface. To address these requirements, this embodiment incorporates the following design.

[0067] This embodiment also includes at least one rotary transmission rod 700, which passes through the base flange 200 and rotates about its own axis to provide R-axis transmission. A magnetohydrodynamic sealing assembly 710 is provided between the rotary transmission rod 700 and the base flange 200.

[0068] The rotary transmission rod 700 refers to a shaft-like component used to transmit rotary motion, with one end connected to the rotary drive mechanism on the atmospheric side and the other end extending into the vacuum chamber 100. The magnetohydrodynamic sealing assembly 710 is a non-contact rotary vacuum sealing device that uses a permanent magnet to form a strong magnetic field in the gap between the rotating shaft and the pole shoe, confining the magnetohydrodynamic fluid within the sealing gap to form a liquid sealing ring.

[0069] When the rotary drive rod 700 rotates around its own axis, the magnetohydrodynamic sealing assembly 710 maintains a vacuum seal between itself and the base flange 200. Since the radial floating structure in the aforementioned scheme has blocked the transmission of bellows radial runout to the flange at its source, the magnetohydrodynamic seal of the rotary drive rod 700 is not affected by linear shaft vibration. Linear and rotary drives can work together on the same base flange 200.

[0070] By integrating the linear drive sealing scheme with the magnetohydrodynamic rotary seal on the same base flange 200, the radial decoupling mechanism of the aforementioned scheme is used to cut off the transmission path of linear shaft vibration to the rotary seal. This achieves reliable integration of the linear and rotary heterogeneous seals while ensuring system compactness and coaxiality.

[0071] like Figure 1The diagram shows (only the structure passing through the outer wall of the vacuum chamber 100 is shown; the manipulator end effector and other components located in the vacuum chamber 100 are transmitted through the corresponding structure; the diagram shows three linear transmission rods 400 with XYZ axes and one rotary transmission rod 700 with R axis; the portion of each transmission rod outside the vacuum chamber 100 is connected to the corresponding drive structure to control the independent movement of each transmission rod). Based on the aforementioned solution that has achieved integrated sealing of single-axis linear and rotary transmission, two further problems exist in the actual application of multi-degree-of-freedom vacuum manipulators: first, different process equipment has different requirements for the number of axes and layout of the manipulator, requiring the technical solution to have flexible expansion capabilities; second, when multiple axes work simultaneously, the magnetohydrodynamic sealing assembly 710 is in a high-temperature environment for a long time, and passive thermal shielding alone is insufficient to maintain it within a safe operating temperature range, posing a risk of decreased sealing performance due to heat conduction. To address these problems, this embodiment has the following design.

[0072] This embodiment includes multiple linear drive rods 400 and multiple rotary drive rods 700, corresponding to at least one of the X-axis, Y-axis, Z-axis, and R-axis movements of the robot arm. A cooling medium flow channel is provided inside the base flange 200, extending to the housing of the magnetohydrodynamic sealing assembly 710.

[0073] Cooling medium flow channel refers to a closed-loop passage formed inside the flange body through machining or casting, used to circulate coolant or cooling gas to actively remove heat from the flange and sealing unit.

[0074] During system operation, multiple linear actuators 400 and rotary actuators 700 are arranged and integrated onto one or more base flanges 200 according to the configuration requirements of the robot arm. Each linear actuator 400 performs axial feed motion in the X, Y, and Z axes, respectively, with its internal radial floating mechanism blocking the transmission of bellows runout to the actuator. Each rotary actuator 700 rotates around its own axis, and the magnetohydrodynamic sealing assembly 710 maintains a vacuum seal between itself and the base flange 200. The control system coordinates the motion of each axis to jointly drive the end effector to complete the predetermined trajectory. Simultaneously, the external cooling circulation system continuously supplies cooling medium into the cooling medium channels inside the base flange 200, continuously removing heat from the housing of the magnetohydrodynamic sealing assembly 710 through convective heat transfer, ensuring that the temperature of the sealing unit is maintained within a safe range.

[0075] By flexibly combining multiple linear drive sealing units and magnetohydrodynamic sealing components 710, multi-degree-of-freedom vacuum robots with different numbers of axes and layouts can be constructed to meet the customized needs of different process equipment, covering common configurations such as rectangular coordinates and cylindrical coordinates. The cooling medium flow channel integrated inside the base flange 200 forms an active cooling system based on the passive labyrinth heat shield, further solving the problem of temperature rise of the sealing unit caused by heat conduction, and ensuring the stability and lifespan of the magnetohydrodynamic seal under long-term high-temperature operation.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. All such modifications or substitutions should be covered within the protection scope of this application, and should not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A multi-degree-of-freedom manipulator that penetrates the walls of a vacuum cavity, characterized in that, include: A base flange (200) is used to be installed on the wall of the vacuum chamber (100), such that the two sides of the base flange (200) face the atmosphere and the interior of the vacuum chamber (100), respectively. A linear drive rod (400) passes through the base flange (200), one end of which is used to connect to the drive mechanism on the atmospheric side, and the other end extends into the vacuum chamber (100) to transmit the linear drive on the atmospheric side to the vacuum chamber (100). A welded bellows (300) is sleeved around the linear transmission rod (400), and its fixed end is sealed and fixed to the vacuum side surface of the base flange (200); A first coupling (510) is axially fixed and sealed to the outer peripheral surface of the linear transmission rod (400); A second fitting (520) is fixedly and sealed to the moving end of the welded bellows (300); The first sleeve (510) and the second sleeve (520) are axially linked so that the axial movement of the linear transmission rod (400) is transmitted to the moving end of the welded bellows (300) through the first sleeve (510) and the second sleeve (520), thereby driving the moving end to extend and retract synchronously. The inner diameter of the second socket (520) is larger than the outer diameter of the linear drive rod (400) to form a radial clearance (521), which provides room for the radial runout of the moving end; The first socket (510) and the second socket (520) can float radially relative to each other to block the transmission of the radial runout to the first socket (510) and the linear transmission rod (400); The internal channels of the first fitting (510), the second fitting (520), the internal space of the welded bellows (300), and the base flange (200) together enclose and define an internal space that is isolated from the interior of the vacuum chamber (100).

2. The multi-degree-of-freedom manipulator for a vacuum cavity through-wall as described in claim 1, characterized in that, The first socket (510) and the second socket (520) are connected by an elastic coupling. The first end of the elastic coupling is fixedly connected to the first socket (510), and the second end is fixedly connected to the second socket (520). The elastic body inside the elastic coupling allows the first end and the second end to float radially relative to each other, so as to realize the radial relative floating between the first socket (510) and the second socket (520).

3. The multi-degree-of-freedom manipulator for a vacuum cavity through-wall as described in claim 1, characterized in that, Multiple radial elastic support plates are evenly arranged circumferentially between the moving end and the fixed end of the welded bellows (300). One end of each elastic support plate is fixed to the moving end of the welded bellows (300), and the other end is fixed to the vacuum side surface of the base flange (200). The radial stiffness of the elastic support plate is 5 to 10 times that of the radial stiffness of the welded bellows (300), and the axial stiffness is 1 / 10 to 1 / 5 of the axial stiffness of the welded bellows (300).

4. The multi-degree-of-freedom manipulator for a vacuum cavity through-wall as described in claim 1, characterized in that, It also includes at least one guide rod (600), which is fixed to the vacuum side surface of the base flange (200); a slider (410) is fixed on the linear transmission rod (400), and the slider (410) is in sliding engagement with the guide rod (600).

5. A multi-degree-of-freedom manipulator for penetrating vacuum chamber walls according to claim 4, characterized in that, The guide rods (600) are in two sets, symmetrically arranged on both sides of the welded corrugated pipe (300), so that the guiding constraint forces on both sides of the linear transmission rod (400) are balanced during axial movement.

6. A multi-degree-of-freedom manipulator for penetrating vacuum chamber walls according to claim 1, characterized in that, It also includes a fixed heat insulation screen (800) and a follower heat insulation cover (900); the fixed heat insulation screen (800) is fixed to the vacuum side surface of the base flange (200), and the follower heat insulation cover (900) is fixed to the linear transmission rod (400) and moves synchronously with it; The fixed heat shield (800) and the follow-up heat shield (900) maintain partial overlap within the range of motion of the linear transmission rod (400) to block heat radiation from inside the vacuum cavity (100).

7. A multi-degree-of-freedom manipulator for a vacuum cavity through-wall as described in claim 6, characterized in that, The fixed heat insulation screen (800) extends a first sleeve structure (810) towards the follower heat insulation cover (900), and the follower heat insulation cover (900) extends a second sleeve structure (910) towards the fixed heat insulation screen (800); the first sleeve structure (810) and the second sleeve structure (910) are nested around the periphery of the linear transmission rod (400), forming a labyrinthine gap channel between them.

8. A multi-degree-of-freedom manipulator for a vacuum cavity through-wall as described in claim 7, characterized in that, The first sleeve structure (810) and the second sleeve structure (910) on the periphery of the linear drive rod (400) have rolled edges (920) at their opposite edges, and there is an axial gap (930) between them along the axial direction, the distance of which is adapted to the stroke of the linear drive rod (400).

9. A vacuum cavity wall-penetrating multi-degree-of-freedom manipulator according to any one of claims 1 to 8, characterized in that, It also includes at least one rotary transmission rod (700) that passes through the base flange (200) and rotates about its own axis to provide R-axis drive; a magnetohydrodynamic sealing assembly (710) is provided between the rotary transmission rod (700) and the base flange (200).

10. A multi-degree-of-freedom manipulator for penetrating vacuum chamber walls according to claim 9, characterized in that, It includes multiple linear drive rods (400) and multiple rotary drive rods (700), which correspond to at least one of the X-axis, Y-axis, Z-axis and R-axis of the robot arm, respectively; the base flange (200) has a cooling medium flow channel inside, which extends to the housing of the magnetohydrodynamic sealing assembly (710).

Images