A turbine molecular pump blade, turbine rotor and turbine molecular pump

Abstract

The present application relates to the technical field of turbo molecular pump, in particular to a kind of turbo molecular pump blade, turbo rotor and turbo molecular pump.Turbo molecular pump blade, the pressure surface and suction surface of blade body are both curved surface, the thickness of the blade body gradually decreases from root to top, the blade thickness of the blade body root is 3.5mm-4.5mm, the blade thickness of the blade body top is 1.5mm-2.5mm, the inlet angle of the blade body is 25°-35°, the outlet angle of the blade body is 40°-50°, the blade inclination of the blade body is 0°-20°.Design as smaller inlet angle and larger outlet angle, can improve the ability of capture, discharge and reverse to prevent backflow to the gas pumping capacity.In the case where other parameters are the same, it can improve the pumping speed and compression ratio of turbo molecular pump, can greatly improve the pumping capacity of turbo molecular pump under low pressure working condition.

Description

Technical Field

[0001] This invention relates to the field of turbomolecular pump technology, specifically to a turbomolecular pump blade, a turbo rotor, and a turbomolecular pump. Background Technology

[0002] As a vacuum-generating device, compound turbomolecular pumps have a wide range of applications in industries that require high vacuum, such as the semiconductor industry. Chip manufacturing requires a high vacuum environment, and compound turbomolecular pumps can extract most of the air from a closed space, bringing the space to the required ultimate vacuum environment.

[0003] In order to reduce costs and shorten the processing cycle, traditional composite turbomolecular pumps in the prior art usually set both the pressure surface and suction surface of the pump blades to be flat, with the blade root to blade tip having the same inclination angle. When the pressure in the enclosed space decreases, the pumping speed and compression ratio of the blades will decrease significantly, resulting in the presence of gases with small molecular weights such as hydrogen in the space, leading to poor pumping performance. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor pumping effect of turbomolecular pumps for gases with small molecular weight in the prior art, thereby providing a turbomolecular pump blade, a turbine rotor and a turbomolecular pump.

[0005] To solve the above-mentioned technical problems, the present invention provides a turbomolecular pump blade, wherein both the pressure surface and the suction surface of the blade body are curved surfaces, the thickness of the blade body gradually decreases from the root to the top, the blade thickness at the root of the blade body is 3.5mm-4.5mm, the blade thickness at the top of the blade body is 1.5mm-2.5mm, the inlet angle of the blade body is 25°-35°, the outlet angle of the blade body is 40°-50°, and the blade tilt angle of the blade body is 0°-20°.

[0006] Optionally, the blade thickness at the root of the blade body is 4 mm, and the blade thickness at the top of the blade body is 2 mm.

[0007] Optionally, the inlet angle of the blade body is 30° and the outlet angle of the blade body is 45°.

[0008] Optionally, the blade tilt angle of the blade body gradually increases from the inlet end to the outlet end, with the blade tilt angle at the inlet end of the blade body being 0° and the blade tilt angle at the outlet end of the blade body being 10°–20°.

[0009] The present invention also provides a turbine rotor, comprising an extraction section, a transition section and a compression section connected in sequence, wherein the extraction section, the transition section and the compression section are each provided with multiple stages of blades along the axial direction;

[0010] Each stage of the extraction section has 16-33 turbomolecular pump blades as described in this invention installed circumferentially.

[0011] Each stage of the transition section has 37-57 transition blades installed circumferentially.

[0012] Each stage of the compression section has 65-66 compression blades installed circumferentially.

[0013] Optionally, the transition blade has an inlet angle of 25°–35°, an outlet angle of 40°–50°, a blade tilt angle of 0°–10°, and a blade thickness of 1.5 mm–3 mm.

[0014] Optionally, the inlet angle of the compression blade is 20°–30°, the outlet angle is 40°–50°, the blade tilt angle is 0°–10°, and the blade thickness is 1.5 mm–3 mm.

[0015] Optionally, the blades on the extraction section have no more than two stages.

[0016] Optionally, the pressure surface and suction surface of the transition blade and the compression blade are both curved surfaces.

[0017] The present invention also provides a turbomolecular pump having the turbo rotor described in the present invention.

[0018] The technical solution of this invention has the following advantages:

[0019] 1. The turbomolecular pump blade provided by the present invention has a curved surface for both the pressure surface and the suction surface of the blade body. The thickness of the blade body gradually decreases from the root to the top. The blade thickness at the root of the blade body is 3.5mm-4.5mm, the blade thickness at the top of the blade body is 1.5mm-2.5mm, the inlet angle of the blade body is 25°-35°, the outlet angle of the blade body is 40°-50°, and the blade tilt angle of the blade body is 0°-20°.

[0020] The turbomolecular pump blades provided by this invention are designed with a smaller inlet angle to improve the capture capability of the pumped gas and a larger outlet angle to improve the discharge capability of the pumped gas and the ability to prevent backflow. By setting both the pressure and suction surfaces as curved surfaces, and using blades with different inclination angles and gradually varying thicknesses from the root to the tip of the blade body, the blades' ability to capture gas and prevent backflow is further improved. Under the same parameters, this increases the pumping speed and compression ratio of the turbomolecular pump, significantly enhancing its pumping capacity under low-pressure conditions.

[0021] 2. The turbomolecular pump blade provided by this invention has a blade inclination angle that gradually increases from the inlet end to the outlet end. The blade inclination angle at the inlet end of the blade body is 0°, and the blade inclination angle at the outlet end of the blade body is 10°–20°. Setting the blade body inclination angle to a gradual change enhances the blade body's ability to capture gas molecules, allowing the gas molecules to move closely against the blade body and preventing the gas from colliding at multiple angles and flowing back during the blade's movement, thereby improving the pumping capacity of the molecular pump.

[0022] 3. The turbine rotor provided by the present invention includes a pumping section, a transition section, and a compression section connected in sequence. Each of the pumping section, the transition section, and the compression section has multiple stages of blades arranged axially. Each stage of blades in the pumping section has 16-33 turbomolecular pump blades as described in the present invention mounted circumferentially. Each stage of blades in the transition section has 37-57 transition blades mounted circumferentially. Each stage of blades in the compression section has 65-66 compression blades mounted circumferentially. By setting the pumping section of the turbine rotor to the turbomolecular pump blades provided by the present invention, the pumping speed of the entire turbomolecular pump, especially the first stage blades, is directly determined. By improving the blades in the pumping section, the overall pumping speed and compression ratio of the turbomolecular pump can be increased, thereby enhancing the pumping capacity of the turbomolecular pump. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a turbomolecular pump blade provided in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the air extraction blade provided in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the turbine rotor provided in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached diagram: 1. Pressure surface; 2. Suction surface; 3. Inlet angle; 4. Outlet angle; 5. Blade tilt angle; 6. Extraction blade; 7. Transition blade; 8. Compression blade. Detailed Implementation

[0028] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] Furthermore, 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.

[0032] Example 1

[0033] like Figure 1 The image shows a turbomolecular pump blade provided in this embodiment. Both the pressure surface 1 and suction surface 2 of the blade body are curved surfaces. The thickness of the blade body gradually decreases from the root to the top. The blade thickness at the root is 3.5mm-4.5mm, and the blade thickness at the top is 1.5mm-2.5mm. The inlet angle 3 of the blade body is 25°-35°, the outlet angle 4 is 40°-50°, and the blade inclination angle 5 is 0°-20°. In this embodiment, the blade thickness at the root is 4mm, and the blade thickness at the top is 2mm. The inlet angle 3 is 30°, and the outlet angle 4 is 45°. The blade inclination angle gradually increases from the inlet end to the outlet end. The blade inclination angle at the inlet end is 0° from the end to the top, and the blade inclination angle at the outlet end gradually increases from 10° to 20° from the end to the top.

[0034] As an alternative implementation, the thickness of the blade body gradually decreases from the root to the tip, with a blade thickness of 3.5 mm at the root and 1.5 mm at the tip. The inlet angle 3 of the blade body is 25°, and the outlet angle 4 of the blade body is 40°.

[0035] As an alternative implementation, the thickness of the blade body gradually decreases from the root to the tip, with a blade thickness of 4.5 mm at the root and 2.5 mm at the tip. The inlet angle 3 of the blade body is 35°, and the outlet angle 4 of the blade body is 50°.

[0036] Example 2

[0037] like Figure 2 and Figure 3 The illustration shows a turbine rotor provided in this embodiment, comprising an extraction section, a transition section, and a compression section connected in sequence. Each of the extraction, transition, and compression sections has multiple stages of blades arranged axially. Specifically, the turbine rotor has eight stages of rotor blades on its central shaft, with the first two stages forming the extraction section, the middle three stages forming the transition section, and the last three stages forming the compression section.

[0038] Each stage of the extraction section has 16-33 extraction blades 6 installed circumferentially, and the extraction blades 6 are all selected from the turbomolecular pump blades provided in Example 1. Each stage of the transition section has 37-57 transition blades 7 installed circumferentially. Each stage of the compression section has 65-66 compression blades 8 installed circumferentially. Specifically, the first stage of the blades has 16 extraction blades 6, the second stage of the blades has 33 extraction blades, the third, fourth, and fifth stages of the blades have 37, 47, and 57 transition blades 7 respectively, the sixth stage of the blades has 65 compression blades 8, and the seventh and eighth stages of the blades have 66 compression blades 8.

[0039] The transition blade 7 has an inlet angle 3 of 25°–35°, an outlet angle 4 of 40°–50°, a blade tilt angle 5 of 0°–10°, and a blade thickness of 1.5 mm–3 mm. Specifically, the transition blade 7 has an inlet angle 3 of 25°, an outlet angle 4 of 50°, and a blade thickness that gradually decreases from 3 mm to 1.5 mm from the root to the tip.

[0040] The inlet angle 3 of the compression blade 8 is 20°–30°, the outlet angle 4 is 40°–50°, the blade tilt angle 5 is 0°–10°, and the blade thickness is 1.5mm–3mm. Specifically, the inlet angle 3 of the compression blade 8 is 20°, the outlet angle 4 is 50°, and the blade thickness gradually decreases from 3mm to 1.5mm from the root to the tip. The pressure surface 1 and suction surface 2 of the transition blade 7 and the compression blade 8 are also curved surfaces.

[0041] The turbine rotor is installed inside the turbomolecular pump. During operation, the turbine rotor rotates axially, and the blades on the rotor drive gas molecules, carrying them out of the enclosed space to create a vacuum. The pumping section of the turbine rotor, especially the first-stage blades, directly determines the overall pumping speed of the turbomolecular pump. By improving the blades in the pumping section, designing a smaller inlet angle and a larger outlet angle, the ability to capture the pumped gas is enhanced, as is the ability to expel the gas and prevent backflow. By making both the pressure and suction surfaces curved, and using blades with different inclination angles and gradually varying thicknesses from the blade root to the blade tip, the ability to capture gas and prevent backflow is further improved. Under the same parameters, this increases the pumping speed and compression ratio of the turbomolecular pump, significantly improving its pumping capacity under low-pressure conditions.

[0042] Example 3

[0043] This embodiment provides a turbomolecular pump having the turbo rotor described in Embodiment 2.

[0044] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A turbomolecular pump blade, characterized in that, The pressure surface (1) and suction surface (2) of the blade body are both curved surfaces. The thickness of the blade body gradually decreases from the root to the top. The blade thickness at the root of the blade body is 3.5mm-4.5mm, and the blade thickness at the top of the blade body is 1.5mm-2.5mm. The inlet angle (3) of the blade body is 25°-35°, and the outlet angle (4) of the blade body is 40°-50°. The blade tilt angle (5) of the blade body gradually increases from the inlet end to the outlet end. The blade tilt angle (5) at the inlet end of the blade body is 0°, and the blade tilt angle (5) at the outlet end of the blade body is 10°-20°. The blade tilt angle at the outlet end of the blade body gradually increases from 10° to 20° from the root of the blade body to the top of the blade body.

2. The turbomolecular pump blade according to claim 1, characterized in that, The thickness of the blade at the root of the blade body is 4 mm, and the thickness of the blade at the top of the blade body is 2 mm.

3. The turbomolecular pump blade according to claim 1 or 2, characterized in that, The inlet angle (3) of the blade body is 30°, and the outlet angle (4) of the blade body is 45°.

4. A turbine rotor, characterized in that, It includes a suction section, a transition section and a compression section connected in sequence, and the suction section, the transition section and the compression section are all provided with multiple stages of blades along the axial direction; Each stage of the extraction section is equipped with 16-33 turbomolecular pump blades as described in any one of claims 1 to 3 circumferentially. Each stage of the transition section has 37-57 transition blades installed circumferentially (7). Each stage of the compression section has 65-66 compression blades installed circumferentially (8).

5. The turbine rotor according to claim 4, characterized in that, The transition blade (7) has an inlet angle (3) of 25°-35°, an outlet angle (4) of 40°-50°, a blade tilt angle (5) of 0°-10°, and a blade thickness of 1.5mm-3mm.

6. The turbine rotor according to claim 4, characterized in that, The inlet angle (3) of the compression blade (8) is 20°-30°, the outlet angle (4) is 40°-50°, the blade tilt angle (5) is 0°-10°, and the blade thickness is 1.5mm-3mm.

7. The turbine rotor according to any one of claims 4 to 6, characterized in that, The number of blades on the extraction section is no more than two stages.

8. The turbine rotor according to any one of claims 4 to 6, characterized in that, The pressure surface (1) and suction surface (2) of the transition blade (7) and the compression blade (8) are both curved surfaces.

9. A turbomolecular pump, characterized in that, It has a turbine rotor as described in any one of claims 4 to 8.

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