Magnetic suspension molecular pump with reinforced traction cylinder structure

Abstract

The utility model relates to the technical field of molecular pumps, in particular to a magnetic suspension molecular pump with a reinforced traction cylinder structure. Comprising a stator, an outer spiral groove is formed in the side wall of the stator, and the center axis of the outer spiral groove coincides with the center axis of the stator; and the rotor is rotatably inserted into the stator, and the central axis of the rotor coincides with the central axis of the stator. The carbon fiber layer has the characteristics of high strength, high temperature resistance, friction resistance, heat conduction, corrosion resistance and the like, has very high constraining force on the traction cylinder, can prevent the traction cylinder from being deformed and expanding outwards, and avoids scratching between the traction cylinder and the side wall of the outer spiral groove, and meanwhile, due to the fact that carbon fibers have the advantage of light weight, the service life of the traction cylinder is prolonged. And the gravity center of the rotor can be prevented from deviating greatly. The carbon fiber layer can also prevent the traction cylinder from being exposed to cause corrosion, and the corrosion resistance of the material is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of molecular pumps, in particular to a magnetic suspension molecular pump with a reinforced traction cylinder structure. Background Art

[0002] Molecular pump is a mechanical turbine vacuum obtaining device designed according to the law of molecular motion. It can obtain ultra-high vacuum and is an essential device for accelerators, electron colliders, lasers and other systems. It has a wide range of applications. Its pumping mechanism is to transfer momentum to gas molecules through the high-speed moving rigid surface in the molecular flow area, so that the gas molecules produce directional flow in the direction of motion of the rigid surface, thereby achieving the purpose of pumping.

[0003] During the operation of the existing molecular pump, the traction cylinder rotates at high speed. Under the influence of high-speed centrifugal force and temperature field, the traction cylinder will expand outward, and the traction cylinder will also show a trend of continuous outward expansion under the action of plastic deformation, which will eventually cause scratches between the traction cylinder and the side wall of the outer spiral groove, causing damage to the traction cylinder and the outer spiral groove. Utility Model Content

[0004] Therefore, the utility model aims to overcome the technical problems in the prior art, thereby providing a magnetic suspension molecular pump with a reinforced traction cylinder structure.

[0005] The utility model provides a magnetic suspension molecular pump with a reinforced traction cylinder structure, comprising:

[0006] The stator has an outer spiral groove on its side wall, and the central axis of the outer spiral groove coincides with the central axis of the stator;

[0007] A rotor is rotatably inserted in the stator, and a central axis of the rotor coincides with a central axis of the stator;

[0008] The rotor comprises a traction cylinder which is inserted into the stator and located inside the outer spiral groove. A first gap is provided between the traction cylinder and the side wall of the outer spiral groove. A carbon fiber layer is provided on the outer side wall of the traction cylinder.

[0009] Furthermore, the carbon fiber layer is located on a portion of the surface of the traction cylinder that is opposite to the outer spiral groove.

[0010] Furthermore, an inner spiral groove is provided on the side wall of the stator, the inner spiral groove is located inside the outer spiral groove, the central axis of the inner spiral groove coincides with the central axis of the stator, and the traction cylinder is located between the inner spiral groove and the outer spiral groove.

[0011] Furthermore, there is a second gap between the side wall of the inner spiral groove and the traction cylinder, and the second gap is smaller than the first gap.

[0012] Furthermore, the rotor further comprises a turbine structure, and the turbine structure comprises:

[0013] The turbine blades are arranged on the inner side of the stator. The turbine blades are arranged in layers. There are a plurality of turbine blades on each layer. The turbine blades on each layer are connected by a connecting shaft.

[0014] Furthermore, the central axis of the connecting shaft coincides with the central axis of the stator, and the traction cylinder is located at the end of the turbine blade and is connected to the connecting shaft.

[0015] Furthermore, among the turbine blades of two adjacent layers, the number of turbine blades located on the side close to the traction cylinder is greater than the number of turbine blades located on the side far from the traction cylinder.

[0016] Furthermore, the turbine blade is a curved structure with variable angle and thickness.

[0017] Furthermore, the turbine blades have eight layers.

[0018] Furthermore, the first gap and the second gap have a value range of 0.2-1 mm.

[0019] The technical solution of this utility model has the following advantages:

[0020] The utility model provides a magnetic levitation molecular pump with a reinforced traction cylinder structure. A carbon fiber layer is arranged on the outer wall of the traction cylinder. The carbon fiber layer has the characteristics of high strength, high temperature resistance, friction resistance, heat conductivity and corrosion resistance. It has a high restraining force on the traction cylinder, which can prevent the traction cylinder from deforming and expanding outward, and avoid scratches between the traction cylinder and the side wall of the outer spiral groove. At the same time, due to the advantage of light weight of carbon fiber, it can also avoid a relatively large deviation of the center of gravity of the rotor. The carbon fiber layer can also prevent the traction cylinder from being exposed and corroded, thereby improving the corrosion resistance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the position of the traction drum of the utility model;

[0023] Figure 2 This is a schematic diagram of the turbine blade structure of the utility model.

[0024] Description of reference numerals;

[0025] 1. External spiral groove; 2. Traction cylinder; 3. First gap; 4. Internal spiral groove; 5. Second gap; 6. Turbine blades. DETAILED DESCRIPTION

[0026] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Example

[0031] like Figure 1 to Figure 2 A specific embodiment of a magnetic levitation molecular pump with a reinforced traction cylinder structure is shown, and the magnetic levitation molecular pump with a reinforced traction cylinder structure includes:

[0032] The stator has an outer spiral groove 1 on its side wall, and the central axis of the outer spiral groove 1 coincides with the central axis of the stator;

[0033] The rotor is rotatably inserted in the stator, and the central axis of the rotor coincides with the central axis of the stator. It should be noted that in the magnetic levitation molecular pump, the arrangement, relative position and function of the stator and the rotor are prior art and will not be described in detail.

[0034] The rotor includes a traction cylinder 2, which is inserted into the stator and located inside the outer spiral groove 1. A first gap 3 is provided between the traction cylinder 2 and the side wall of the outer spiral groove 1. A carbon fiber layer is provided on the outer side wall of the traction cylinder 2. There is also a gap between the carbon fiber layer and the side wall of the outer spiral groove 1. The first gap 3 can prevent the traction cylinder 2 from scratching the side wall of the outer spiral groove 1. However, when the traction cylinder 2 rotates at high speed, under the influence of high-speed centrifugal force and temperature field, the traction cylinder 2 will expand outward, and the traction cylinder 2 will also show a trend of continuous expansion outward under the action of plastic deformation, which may cause scratches between the traction cylinder 2 and the side wall of the outer spiral groove 1. The present application sets a carbon fiber layer on the outer wall of the traction cylinder 2. The carbon fiber layer has the characteristics of high strength, high temperature resistance, friction resistance, heat conduction and corrosion resistance. It has a high restraint force on the traction cylinder 2, which can prevent the traction cylinder 2 from deforming and expanding outward, and avoid scratches between the traction cylinder 2 and the side wall of the outer spiral groove 1. At the same time, due to the advantage of light weight of carbon fiber, it can also avoid a relatively large deviation of the center of gravity of the rotor. The carbon fiber layer can also prevent the traction cylinder 2 from being exposed and corroded, thereby improving the corrosion resistance of the material.

[0035] It should be noted that the rotor is processed using a piece of integral bar stock. Since the bar stock used complies with "GB / T 3191-2010 Aluminum and Aluminum Alloy Extruded Bar Stock", the mechanical properties of the 7-series aluminum alloy are only required to be less than or equal to 250mm. The diameter of the rotor is about 300mm. For large-diameter extruded bar stock, the strength near the outside is very high, but the strength of the core is difficult to meet the standard. This results in low strength at the core of the impeller during actual use, and plastic deformation will occur during long-term operation. The appearance of plastic deformation is still a little aggravated during long-term use, and in severe cases, the pump will be scrapped. The present application sets a carbon fiber layer on the outer wall of the traction cylinder 2 to alleviate the pump scrapping caused by plastic deformation.

[0036] Furthermore, the carbon fiber layer is located on the partial surface of the traction cylinder 2 opposite to the outer spiral groove 1. The carbon fiber layer can be arranged only on a partial surface of the side wall of the traction cylinder 2, that is, the carbon fiber layer is arranged on the side wall of the traction cylinder 2 opposite to the outer spiral groove 1.

[0037] Furthermore, an inner spiral groove 4 is provided on the side wall of the stator. The inner spiral groove 4 is located inside the outer spiral groove 1 . The central axis of the inner spiral groove 4 coincides with the central axis of the stator. The traction cylinder 2 is located between the inner spiral groove 4 and the outer spiral groove 1 .

[0038] Furthermore, a second gap 5 is provided between the side wall of the inner spiral groove 4 and the traction cylinder 2, and the second gap 5 is smaller than the first gap 3. The traction cylinder 2 achieves relative rotation with the stator through the first gap 3 and the second gap 5.

[0039] Furthermore, the rotor further comprises a turbine structure, and the turbine structure comprises:

[0040] The turbine blades 6 are arranged on the inner side of the stator. The turbine blades 6 are arranged in layers. There are a plurality of turbine blades 6 on each layer. The turbine blades 6 on each layer are connected by a connecting shaft.

[0041] Furthermore, the central axis of the connecting shaft coincides with the central axis of the stator, and the traction cylinder 2 is located at the end of the turbine blade 6 and connected to the connecting shaft.

[0042] Furthermore, in two adjacent layers of turbine blades 6 , the number of turbine blades 6 located on the side close to the traction cylinder 2 is greater than the number of turbine blades 6 located on the side away from the traction cylinder 2 .

[0043] Furthermore, the turbine blades 6 are of a curved surface structure with a variable angle and thickness. The number of turbine blades 6 in each layer increases step by step, and each layer of turbine blades 6 adopts a curved surface structure, thereby increasing the cross-sectional area swept by the turbine blades 6. The traction cylinder 2 cooperates with the inner spiral groove 4 and the outer spiral groove 1 respectively, and removes the gas molecules sequentially along the inner spiral groove 4 and the outer spiral groove 1 through the surface to avoid backflow.

[0044] Furthermore, the turbine blades 6 have eight layers.

[0045] Furthermore, the first gap 3 and the second gap 5 have a value range of 0.2-1 mm. It should be noted that the gap between the carbon fiber layer and the outer spiral groove 1 can also be 0.2-1 mm.

[0046] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A magnetic levitation molecular pump with a reinforced traction cylinder structure, characterized in that: include: A stator, wherein an outer spiral groove (1) is arranged on a side wall, and a central axis of the outer spiral groove (1) coincides with a central axis of the stator; A rotor is rotatably inserted in the stator, and a central axis of the rotor coincides with a central axis of the stator; The rotor comprises a traction cylinder (2), the traction cylinder (2) is inserted into the stator and is located on the inner side of the outer spiral groove (1), a first gap (3) is provided between the traction cylinder (2) and the side wall of the outer spiral groove (1), and a carbon fiber layer is provided on the outer side wall of the traction cylinder (2).

2. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 1, characterized in that: The carbon fiber layer is located on a portion of the surface of the traction cylinder (2) that is opposite to the outer spiral groove (1).

3. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 1, characterized in that: An inner spiral groove (4) is also provided on the side wall of the stator. The inner spiral groove (4) is located inside the outer spiral groove (1). The central axis of the inner spiral groove (4) coincides with the central axis of the stator. The traction cylinder (2) is located between the inner spiral groove (4) and the outer spiral groove (1).

4. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 3, characterized in that: A second gap (5) is provided between the side wall of the inner spiral groove (4) and the traction cylinder (2), and the second gap (5) is smaller than the first gap (3).

5. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 1, characterized in that: The rotor further comprises a turbine structure, wherein the turbine structure comprises: The turbine blades (6) are arranged on the inner side of the stator. The turbine blades (6) are arranged in layers. The number of turbine blades (6) in each layer is several, and the turbine blades (6) in each layer are connected via a connecting shaft.

6. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 5, characterized in that: The central axis of the connecting shaft coincides with the central axis of the stator, and the traction cylinder (2) is located at the end of the turbine blade (6) and is connected to the connecting shaft.

7. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 5, characterized in that: Among the turbine blades (6) of two adjacent layers, the number of turbine blades (6) located on the side close to the traction cylinder (2) is greater than the number of turbine blades (6) located on the side far from the traction cylinder (2).

8. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 5, characterized in that: The turbine blade (6) is a curved surface structure with variable angle and thickness.

9. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 5, characterized in that: The turbine blades (6) have eight layers.

10. The magnetic levitation molecular pump with a reinforced traction cylinder structure according to claim 4, characterized in that: The first gap (3) and the second gap (5) have a value range of 0.2-1 mm.

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