Rotary sealing device applied to strong magnetic field and high vacuum

Abstract

The invention discloses a rotary sealing device under a strong magnetic field and high vacuum. The rotary sealing device comprises an adjusting spiral lead screw, a connecting flexible shaft, a supporting frame and a rotary sealing mechanism which are sequentially arranged in a vacuum chamber. The adjusting spiral lead screw is connected with the rotary sealing mechanism through the connecting flexible shaft and the supporting frame, and the front-back position of a target component in the vacuum chamber is adjusted. The rotary sealing mechanism comprises a rotary shaft and a rotary supporting sealing outer cylinder; the rotating shaft and the adjusting spiral lead screw are used for adjusting the front-back position of a target component in the vacuum chamber on line, and the rotating supporting sealing outer cylinder is used for conducting vacuum sealing and axial centering guiding on the rotating shaft in the moving process. The guide mechanism with the upper bearing and the lower bearing is adopted, so that the center of the rotating shaft cannot be eccentric all the time in the rotating process, the sealing ring around the rotating shaft is stressed uniformly and cannot be damaged too early due to serious abrasion of a certain place, and the sealing effect of a high-intensity magnetic field and high vacuum is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of high vacuum technology, and in particular relates to a rotary sealing device used in strong magnetic fields and high vacuum. Background Art

[0002] The large vacuum chamber of a particle accelerator is an environment of strong magnetic field and high vacuum. Many components are installed in the vacuum chamber of strong magnetic field and high vacuum. These components need to be adjusted in position during installation. The position adjustment is to adjust the front and rear position of the target component through the linear motion of the driving motor.

[0003] Adjusting the front and rear position of the target component generally needs to be divided into two steps: offline coarse position adjustment in an atmospheric environment and online fine position adjustment in a vacuum environment. When performing online fine position adjustment in a vacuum environment, the drive motor cannot be arranged in a vacuum environment but must be arranged outside the vacuum chamber. The drive motor must transmit power to the target component in the vacuum chamber through the transmission shaft, so that part of the transmission shaft is in a vacuum environment and the other part is in an atmospheric environment. In order to ensure the vacuum sealing effect, an online vacuum sealing device needs to be set at the junction of the vacuum and atmosphere of the transmission shaft.

[0004] The online vacuum sealing device of the prior art usually adopts three structures: the first is the combination of magnetic fluid seal + lead screw; the second is directly using linear motion feedthrough; the third is bellows + shaft structure. The first structure above cannot operate under a strong magnetic field: although it can adjust the position over a long distance, it cannot operate under a strong magnetic field due to the special structural properties of the magnetic fluid seal; the second structure above will affect the local vacuum degree when the shaft moves from the atmospheric section to the vacuum chamber: the second structure can generally adjust the position in a small range, but due to its thin shaft diameter, it cannot withstand a large load, so it is adjusted without bearing a large force, and during the movement, the shaft surface will absorb a certain amount of gas, which will affect the local vacuum degree when the shaft moves from the atmospheric section to the vacuum chamber; the third structure above takes up a large space: although it is feasible to achieve position adjustment within a certain range by utilizing the compressibility of the bellows, due to the size and structural characteristics of the bellows, it is usually large in size and requires a large space. Therefore, it is necessary to design an online position adjustment device under high vacuum. The online position adjustment device needs to have high vacuum, resistance to strong magnetic fields, ability to withstand large loads, compact structure, and simplified installation, debugging, and convenient maintenance. It must have high reliability and high stability during long-term use to ensure the sealing of the vacuum chamber and the requirements of static vacuum and dynamic vacuum, reduce maintenance costs, and extend service life. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention proposes a rotary sealing device for use in strong magnetic fields and high vacuums, with the aim of solving the problems that the line position adjustment device can maintain a high vacuum degree in the vacuum chamber, can withstand strong magnetic fields, can bear large loads, and has a compact structure, simplified installation, and high reliability and stability.

[0006] The present invention adopts the following technical solutions to solve the technical problems:

[0007] A rotary sealing device under strong magnetic field and high vacuum, comprising: an adjusting screw (1), a connecting flexible shaft (2), a support frame (3) arranged in sequence in a vacuum chamber, and a rotary sealing mechanism (4) arranged partly in the vacuum chamber and partly in the vacuum chamber; the adjusting screw (1) has a front end connected to a target component (5) in the vacuum chamber, and a rear end connected to the rotary sealing mechanism (4) via the connecting flexible shaft (2); the rotary sealing mechanism (4) adjusts the front and rear position of the target component (5) in the vacuum chamber; the characteristics are:

[0008] The rotary sealing mechanism (4) comprises a rotary shaft (4-1) and a rotary support sealing outer cylinder (4-2); the rotary shaft (4-1) and the adjusting screw screw (1) are used to online adjust the front and rear positions of a target component (5) in a vacuum chamber, and the rotary support sealing outer cylinder (4-2) is used to perform vacuum sealing and axial centering guidance on the rotary shaft during movement.

[0009] Furthermore, one end of the rotating shaft (4-1) is connected to the target component (5) in the vacuum chamber by adjusting the spiral screw (1), and the other end extends out of the vacuum chamber; the rotating seal supporting outer cylinder (4-2) is wrapped around the periphery of the vacuum and atmosphere interface of the rotating shaft, and the rotating seal supporting outer cylinder (4-2) is provided with: a rotating shaft (4-1), a rotating shaft sealing guide mechanism (4-2-1), and a rotating shaft supporting outer cylinder (4-2-2) in sequence from the inside to the outside.

[0010] Furthermore, the rotating shaft sealing guide mechanism (4-2-1) is provided with: an elastic retaining ring (4-2-1-1), an O-shaped sealing ring (4-2-1-2), and a bearing guide mechanism (4-2-1-3) in sequence along the axial direction, and the bearing guide mechanism (4-2-1-3) enables the rotating shaft (4-1) to always rotate in a centered manner along the axial direction during the rotation process.

[0011] Furthermore, the bearing guide mechanism (4-2-1-3) comprises an upper support bearing (4-2-1-3-1) and a lower support bearing (4-2-1-3-2), and a bearing support frame (4-2-1-3-3) between the upper support bearing and the lower support bearing.

[0012] Furthermore, the adjusting spiral screw (1) is composed of a nut and a screw, and linear motion is achieved by rotating the adjusting spiral screw (1), thereby adjusting the position of the target component to a desired position.

[0013] Furthermore, the connecting flexible shaft (2) is used to respectively connect the rotating shaft (4-1) and the adjusting spiral screw (1) to achieve motion transmission between them.

[0014] Furthermore, the support frame (3) is used to connect the outer wall of the vacuum chamber and the adjusting screw (1) to achieve relative fixation of the position of the nut.

[0015] Advantages and effects of the present invention

[0016] 1. The present invention realizes a rotary sealing device in a strong magnetic field and high vacuum environment by adjusting the overall design of the spiral screw 1, the connecting flexible shaft 2, the support frame 3, the rotary sealing mechanism 4, and the specific structure of the bearing guide mechanism 4-2-1-3. The rotary sealing device can be used in a high vacuum, strong magnetic field, and high load environment, and solves the problem that each time the position is adjusted, the vacuum needs to be broken and the vacuum chamber needs to be opened to adjust the position of the internal device, thereby simplifying the operation process and improving work efficiency.

[0017] 2. The present invention adopts a guide mechanism with an upper bearing and a lower bearing, so that the center of the rotating shaft will never be eccentric during the rotation process, so that the sealing ring around the rotating shaft is evenly stressed and will not be damaged prematurely due to severe wear in a certain place, thereby ensuring a high vacuum sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an application effect diagram of the rotary sealing device of the present invention used in a strong magnetic field and a high vacuum;

[0019] Figure 2 for Figure 1 A partial enlarged view of

[0020] Figure 3a Schematic diagram of the rotary sealing mechanism of the present invention Figure 1 ;

[0021] Figure 3b Schematic diagram of the rotary sealing mechanism of the present invention Figure 2 ;

[0022] Figure 3c This is a third schematic diagram of the rotary sealing mechanism of the present invention;

[0023] In the figure, 1: adjusting bolt screw; 2: connecting flexible shaft; 3: supporting frame; 4: rotating sealing shaft; 4-1: rotating shaft; 4-2: rotating supporting sealing outer cylinder; 4-2-1: rotating shaft sealing guide mechanism; 4-2-2: rotating shaft supporting outer cylinder; 4-2-1-1: elastic retaining ring; 4-2-1-2: O-shaped sealing ring; 4-2-1-3: bearing guiding mechanism; 4-2-1-3-1: upper supporting bearing; 4-2-1-3-2: lower supporting bearing; 4-2-1-3-3: bearing supporting frame; 5: target component. DETAILED DESCRIPTION

[0024] Design principle of the present invention

[0025] 1. Difficulty in the design of the present invention: The difficulty lies in that the vacuum sealing device is a seal in a moving state rather than a seal in a static state. The position of the rotating shaft in a static state is relatively stationary, while the sealing in a moving state requires the rotational motion of the rotating shaft to be converted into the linear motion of the screw. During the sealing process, the rotating shaft is required to rotate all the time. Due to the influence of centrifugal force during the rotation of the rotating shaft, it is easy for the center of the shaft to shift. Once the shift occurs, the sealing ring surrounding the rotating shaft is unevenly stressed, resulting in greater wear in some places and less wear in others. The sealing effect becomes weaker in places with greater wear, resulting in vacuum leakage.

[0026] 2. Innovation of the present invention: One of the innovations is that a sealing outer cylinder 4-2 with a rotation support function is designed. The difference from the existing sealing structure is that the existing sealing structure only has a sealing ring but no rotation support function. The present invention has modified the traditional sealing structure, and the sealing ring and the support bearing together form a rotation sealing structure. The rotation support function is to make the center point of the rotating shaft 4-1 always coincide with the center point of the upper support bearing 4-2-1-3-1 and the lower support bearing 4-2-1-3-2 and the bearing support frame 4-2-1-3-3 during the rotation process without eccentricity. The second innovation is that the method of element substitution has achieved unexpected results. The present invention uses the method of adjusting the screw bolt 1+connecting the flexible shaft 2+rotating shaft 4-1+rotating support sealing outer cylinder 4-2 to replace the method of the existing technology with a bulky bellows + shaft structure, solving the problem that the existing technology bellows + shaft structure occupies a large space.

[0027] A rotary sealing device under strong magnetic field and high vacuum, such as Figure 1 , Figure 2 , Figure 3a , Figure 3b , Figure 3cAs shown, the rotary sealing device comprises: an adjusting screw 1, a connecting flexible shaft 2, a supporting frame 3 arranged in sequence in the vacuum chamber, and a rotary sealing mechanism 4 arranged partly in the vacuum chamber and partly outside the vacuum chamber; the adjusting screw 1 has its front end connected to a target component (5) in the vacuum chamber, and its rear end connected to the rotary sealing mechanism 4 through the connecting flexible shaft 2, and the rotary sealing mechanism 4 is used to adjust the front and rear position of the target component 5 in the vacuum chamber; the characteristics are:

[0028] like Figure 3a As shown, the rotary sealing mechanism 4 includes a rotary shaft 4-1 and a rotary support sealing outer cylinder 4-2; the rotary shaft 4-1 and the adjusting screw 1 are used to online adjust the front and rear positions of the target component 5 in the vacuum chamber, and the rotary support sealing outer cylinder 4-2 is used to perform vacuum sealing and axial centering guidance on the rotary shaft during movement.

[0029] like Figure 3a As shown, one end of the rotating shaft 4-1 is connected to the target component 5 in the vacuum chamber by adjusting the spiral screw 1, and the other end extends out of the vacuum chamber; the rotating seal supporting outer cylinder 4-2 is wrapped around the periphery of the vacuum and atmosphere junction of the rotating shaft, and the rotating seal supporting outer cylinder 4-2 is provided with: the rotating shaft 4-1, the rotating shaft sealing guide mechanism 4-2-1, and the rotating shaft supporting outer cylinder 4-2-2 in sequence from the inside to the outside.

[0030] like Figure 3b As shown, the rotating shaft sealing guide mechanism 4-2-1 is provided with: an elastic retaining ring 4-2-1-1, an O-ring 4-2-1-2, and a bearing guide mechanism 4-2-1-3 in sequence along the axial direction. The bearing guide mechanism 4-2-1-3 enables the rotating shaft 4-1 to always rotate in the axial direction during the rotation process.

[0031] like Figure 3c As shown, the bearing guide mechanism 4-2-1-3 includes an upper support bearing 4-2-1-3-1 and a lower support bearing 4-2-1-3-2, and a bearing support frame 4-2-1-3-3 between the upper support bearing and the lower support bearing.

[0032] like Figure 1 As shown, the adjusting spiral screw 1 is composed of a nut and a screw, and linear motion is achieved by rotating the adjusting spiral screw 1, thereby adjusting the position of the target component to the desired position.

[0033] like Figure 2 , Figure 3a As shown, the connecting flexible shaft 2 is used to respectively connect the rotating shaft 4-1 and the adjusting spiral screw (1) to achieve motion transmission between them.

[0034] like Figure 1As shown, the support frame 3 is used to connect the outer wall of the vacuum chamber and the adjusting screw 1 to achieve relative fixation of the position of the nut.

[0035] It should be emphasized that the above specific embodiments are merely explanations of the present invention, and they are not limitations of the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without any creative contribution as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A rotary sealing device under strong magnetic field and high vacuum, the rotary sealing device comprising: An adjusting screw (1), a connecting flexible shaft (2), a support frame (3) are sequentially arranged in the vacuum chamber, and a rotating sealing mechanism (4) is partially arranged outside the vacuum chamber and partially arranged outside the vacuum chamber; the adjusting screw (1) has a front end connected to a target component (5) in the vacuum chamber, and a rear end connected to the rotating sealing mechanism (4) via the connecting flexible shaft (2), and the rotating sealing mechanism (4) is used to adjust the front and rear position of the target component (5) in the vacuum chamber; Its special proof is: The rotary sealing mechanism (4) comprises a rotary shaft (4-1) and a rotary support sealing outer cylinder (4-2); the rotary shaft (4-1) and the adjusting screw screw (1) are used to online adjust the front and rear positions of a target component (5) in a vacuum chamber, and the rotary support sealing outer cylinder (4-2) is used to perform vacuum sealing and axial centering guidance on the rotary shaft during movement.

2. A rotary sealing device under strong magnetic field and high vacuum according to claim 1, characterized in that: The rotating shaft (4-1) has one end connected to a target component (5) in a vacuum chamber via an adjustable screw screw (1), and the other end extending out of the vacuum chamber; the rotating seal supporting outer cylinder (4-2) is wrapped around the periphery of the vacuum and atmosphere interface of the rotating shaft, and the rotating seal supporting outer cylinder (4-2) is provided with, from the inside to the outside, the rotating shaft (4-1), a rotating shaft sealing guide mechanism (4-2-1), and a rotating shaft supporting outer cylinder (4-2-2).

3. The rotary sealing device under strong magnetic field and high vacuum according to claim 2, characterized in that: The rotating shaft sealing guide mechanism (4-2-1) is provided with: an elastic retaining ring (4-2-1-1), an O-shaped sealing ring (4-2-1-2), and a bearing guide mechanism (4-2-1-3) in sequence along the axial direction. The bearing guide mechanism (4-2-1-3) enables the rotating shaft (4-1) to always rotate in a centered manner along the axial direction during the rotation process.

4. The rotary sealing device under strong magnetic field and high vacuum according to claim 3, characterized in that: The bearing guide mechanism (4-2-1-3) comprises an upper support bearing (4-2-1-3-1), a lower support bearing (4-2-1-3-2), and a bearing support frame (4-2-1-3-3) between the upper support bearing and the lower support bearing.

5. The rotary sealing device under strong magnetic field and high vacuum according to claim 1, characterized in that: The adjusting spiral lead screw (1) is composed of a nut and a lead screw, and linear motion is achieved by rotating the adjusting spiral lead screw (1), thereby adjusting the position of the target component to a desired position.

6. The rotary sealing device under strong magnetic field and high vacuum according to claim 1, characterized in that: The connecting flexible shaft (2) is used to respectively connect the rotating shaft (4-1) and the adjusting spiral screw (1) to achieve motion transmission between them.

7. The rotary sealing device under strong magnetic field and high vacuum according to claim 5, characterized in that: The support frame (3) is used to connect the outer wall of the vacuum chamber and the adjusting screw (1) to achieve relative fixation of the position of the nut.

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