Centrifugal impeller capable of reducing axial force and leakage rate simultaneously and fan structure

Abstract

The utility model discloses a centrifugal impeller and fan structure capable of simultaneously reducing axial force and leakage rate, the centrifugal impeller comprises a wheel disc, a plurality of main blades are uniformly arranged on the front surface of the wheel disc, and a plurality of binary auxiliary blades are uniformly arranged on the back surface of the wheel disc. The rotating directions of the main blades and the binary auxiliary blades are arranged in the pressure increasing direction, the structure that the binary auxiliary blades are arranged on the back face of the impeller is adopted, when the impeller rotates, the auxiliary blades drive air on the back face of the wheel disc to do centrifugal motion, and the vacuum effect is formed on the back face of the wheel disc. On one hand, the air quantity leaked from the shaft end sealing structure by the impeller can be greatly reduced, and on the other hand, the axial force is greatly reduced, the load of a thrust bearing is reduced, and the mechanical loss is reduced; according to the two advantages, the overall efficiency of the compressor is improved, and the operation cost of a unit is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of fan equipment, in particular to a centrifugal impeller and a fan capable of reducing axial force and leakage at the same time. Background Art

[0002] The impeller of a centrifugal compressor, also known as the working wheel, is the only element that does work on the airflow and is the heart of the compressor. The gas rotates at high speed with the impeller under the action of the impeller blades. The gas is affected by the centrifugal force of the rotation and the diffusion flow in the impeller and the diffuser behind it, which increases the pressure and speed after passing through the impeller and diffuser.

[0003] Existing impellers often have certain problems and defects in actual use. First, due to the different axial areas of the impeller disc and the wheel cover, especially the semi-open impeller, under the action of gas pressure, a large axial thrust is generated from the disc to the wheel cover, and the axial thrust of the compressor is mainly borne by the thrust bearing. If the axial thrust is too large, it will lead to difficulties in bearing selection and increased power consumption; in addition, the gas pressure on the back of the impeller is too high, which will cause a large leakage of the compressed medium at the shaft end seal, thereby causing energy loss and reducing the overall efficiency of the centrifugal compressor. Especially for chemical gases or toxic gases, if there is a gas leak, it will cause certain harm to the working environment. Utility Model Content

[0004] Purpose of the utility model: In order to overcome the problems existing in the prior art, the utility model provides a centrifugal impeller and fan structure that can reduce the axial force and leakage at the same time. The structure adopts a dual auxiliary blade arrangement on the back of the impeller. When the impeller rotates, the auxiliary blades drive the pneumatic motion on the back of the wheel to centrifugal motion, forming a vacuum effect on the back of the wheel. On the one hand, it can greatly reduce the amount of gas leakage from the shaft end sealing structure of the impeller, and on the other hand, it greatly reduces the axial force and reduces the load on the thrust bearing, thereby reducing mechanical losses. Both of these advantages improve the overall efficiency of the compressor and save the operating cost of the unit.

[0005] Technical solution: The utility model provides the following technical solutions:

[0006] A centrifugal impeller capable of reducing axial force and leakage at the same time, the centrifugal impeller comprises a wheel disc, a plurality of main blades are evenly arranged on the front side of the wheel disc, a plurality of binary auxiliary blades are evenly arranged on the back side of the wheel disc, and the rotation direction of the main blades and the binary auxiliary blades is arranged in the direction of increasing pressure.

[0007] Preferably, the main blades include three-element long blades and splitter blades.

[0008] Preferably, the three-element long blades and splitter blades are arranged at intervals around the center of the wheel disc.

[0009] Preferably, the number of the main blades is 10-22.

[0010] Preferably, the number of the three-element long blades is 5-11, and the number of the splitter blades is the same as the number of the three-element long blades.

[0011] Preferably, the number of the binary auxiliary blades is 9-22.

[0012] Preferably, the inlet and outlet angles of the binary auxiliary blades are between 25° and 55°.

[0013] A fan structure includes a casing, a main shaft is rotatably arranged on the casing, a centrifugal impeller is connected to the main shaft, and a diffuser is arranged on the casing in the air outlet direction of the centrifugal impeller. The centrifugal impeller is the centrifugal impeller described above.

[0014] Preferably, the inlet end of the diffuser is a double-sided chamfered structure.

[0015] Preferably, a comb teeth seal is provided between the housing and the main shaft.

[0016] Beneficial effects: Compared with the prior art, the utility model has the following advantages:

[0017] 1. The structure of arranging dual auxiliary blades on the back of the impeller is adopted. When the impeller rotates, the auxiliary blades drive the pneumatic motion on the back of the impeller to centrifugal motion, forming a vacuum effect on the back of the impeller. On the one hand, it can greatly reduce the amount of gas leakage from the shaft end sealing structure of the impeller, and on the other hand, it greatly reduces the axial force and the load of the thrust bearing, thereby reducing the mechanical loss. These two advantages improve the overall efficiency of the compressor and save the operating cost of the unit.

[0018] 2. The auxiliary blades on the back of the impeller also act as reinforcing ribs, improving the strength and rigidity of the impeller. With the same material, the impeller can reach a higher outlet linear velocity, thereby improving the work capacity of the impeller and achieving a greater pressure rise. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the centrifugal fan of the utility model;

[0020] Figure 2 It is a three-dimensional diagram of the centrifugal impeller of the utility model;

[0021] Figure 3 This is a back view of the centrifugal impeller of the utility model;

[0022] Figure 4 This is an enlarged view of the comb teeth sealing structure of the centrifugal fan of the utility model;

[0023] Description of reference numerals:

[0024] 1. Centrifugal impeller; 2. Main blades; 21. Three-dimensional long blades; 22. Diverter blades; 3. Diffuser; 4. Two-dimensional auxiliary blades; 5. Casing; 6. Disc; 7. Sealing screws; 8. Comb seal. DETAILED DESCRIPTION

[0025] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0026] Any feature disclosed in this specification (including any additional claims, abstracts and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings.

[0028] like Figure 2 , 3 As shown, in the first embodiment of the utility model, a centrifugal impeller capable of reducing axial force and leakage at the same time, the centrifugal impeller 1 includes a wheel disc 6, a number of main blades 2 are evenly arranged on the front of the wheel disc 6, and a number of binary auxiliary blades 4 are evenly arranged on the back of the wheel disc 6, and the rotation direction of the main blades and the binary auxiliary blades 4 are arranged in the direction of increased pressure.

[0029] In this embodiment, the main blades include a three-element long blade 21 and a splitter blade 22 .

[0030] In this embodiment, the three-element long blades 21 and the splitter blades 22 are arranged at intervals around the center of the wheel disc 6 .

[0031] The number of main blades is 10-22. The specific number of main blades is determined according to aerodynamic design and analysis. In this embodiment, the number of main blades 2 is 20.

[0032] There are ten three-element long blades 21 , and the number of splitter blades 22 is the same as that of the three-element long blades 21 , which is also ten.

[0033] The number of the binary auxiliary blades is 9-22, and the inlet and outlet angles are between 25°-55°. In this embodiment, the number of the binary auxiliary blades 4 is 19.

[0034] In the second embodiment of the present invention, Figure 1 , 4As shown, based on the centrifugal impeller, a fan structure is also disclosed, including a casing 5 and the centrifugal impeller described in the above embodiment, the casing 5 is rotatably provided with a main shaft, the main shaft is connected to the centrifugal impeller 1, and the casing 5 is provided with a diffuser 3 in the air outlet direction of the centrifugal impeller 1.

[0035] The inlet end of the diffuser 3 is a double-sided chamfered structure so that the airflows from the main blades 2 and the auxiliary blades 4 can smoothly enter the flow channel of the diffuser 3, avoiding the airflow colliding with the casing 5 to cause flow loss and generate large noise.

[0036] A comb-teeth seal 8 is provided between the housing and the main shaft. The comb-teeth seal 8 is integrally processed and fixed to the housing 5 by a seal screw 7 .

[0037] Working principle: When the centrifugal impeller rotates, the auxiliary blades drive the air on the back of the impeller 6 to do centrifugal motion, forming a vacuum effect on the back of the impeller 6, reducing the gas pressure there. On the one hand, it can greatly reduce the amount of gas leaking from the shaft end seal 8 of the impeller 1, and on the other hand, it greatly reduces the axial force and the load on the thrust bearing, thereby reducing the mechanical loss of the rotor and improving the overall efficiency of the unit. The auxiliary blades on the back of the impeller also play the role of reinforcing ribs, improving the strength and rigidity of the impeller. Under the same material, the impeller can achieve a higher outlet linear velocity, thereby improving the working capacity of the impeller and achieving a greater pressure rise.

[0038] The purpose of the above embodiments is to exemplarily reproduce and deduce the technical solution of the utility model, and to fully describe the technical solution, purpose and effect of the utility model. Its purpose is to make the public understand the disclosed content of the utility model more thoroughly and comprehensively, and it does not limit the protection scope of the utility model.

[0039] The above embodiments are not exhaustive enumerations based on the present invention, and there may be multiple other implementations not listed. Any replacement and improvement made without violating the concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A centrifugal impeller capable of reducing both axial force and leakage, characterized in that: The centrifugal impeller comprises a wheel disc (6), a plurality of main blades (2) are evenly arranged on the front of the wheel disc (6), a plurality of binary auxiliary blades (4) are evenly arranged on the back of the wheel disc (6), and the rotation direction of the main blades and the binary auxiliary blades (4) are arranged in the direction of increasing pressure.

2. A centrifugal impeller capable of reducing axial force and leakage at the same time according to claim 1, characterized in that: The main blade comprises a three-element long blade (21) and a splitter blade (22).

3. A centrifugal impeller capable of reducing axial force and leakage at the same time according to claim 2, characterized in that: The three-element long blades (21) and the splitter blades (22) are arranged at intervals around the center of the wheel disc (6).

4. A centrifugal impeller capable of reducing axial force and leakage at the same time according to claim 1, characterized in that: The number of the main blades (2) is 10-22.

5. A centrifugal impeller capable of reducing axial force and leakage at the same time according to claim 3, characterized in that: The number of the three-element long blades (21) is 5 to 11, and the number of the splitter blades (22) is the same as that of the three-element long blades (21).

6. A centrifugal impeller capable of reducing axial force and leakage simultaneously according to claim 1, characterized in that: The number of the binary auxiliary blades (4) is 9-22.

7. A centrifugal impeller capable of reducing axial force and leakage simultaneously according to claim 6, characterized in that: The inlet and outlet angles of the binary auxiliary blade (4) are between 25° and 55°.

8. A fan structure, comprising a casing (5), a main shaft rotatably arranged on the casing (5), a centrifugal impeller (1) connected to the main shaft, and a diffuser (3) arranged on the casing (5) in the air outlet direction of the centrifugal impeller (1), characterized in that: The centrifugal impeller is the centrifugal impeller according to any one of claims 1 to 7.

9. A fan structure according to claim 8, characterized in that: The inlet end of the diffuser (3) is a double-sided chamfered structure.

10. A fan structure according to claim 8, characterized in that: A comb teeth seal (8) is arranged between the casing and the main shaft.

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