Impeller sealing structure of magnetic levitation high-speed centrifuge

Abstract

An impeller sealing structure of a magnetic levitation high-speed centrifuge, comprising: an annular seal (1), mounted between an impeller (2) and a motor front end cover (3) and sleeved on a rotor (4), wherein continuous radial sealing teeth (5) are circumferentially formed on the side surface of the annular seal (1) facing the impeller (2), and continuous axial sealing teeth (6) are formed on the inner annular wall of the annular seal (1); and impeller sealing teeth (10), provided on the side surface of the impeller (2) facing the annular seal (1), wherein the impeller sealing teeth (10) are engaged with the radial sealing teeth (5), a sealing cavity (7) is formed among the annular seal (1), the rotor (4) and the impeller (2), the annular seal (1) is provided with a first fluid channel (8) in communication with the sealing cavity (7), and the motor front end cover (3) is provided with a second fluid channel (9) in communication with the first fluid channel (8) and the outside of the centrifuge. The structure has a good sealing effect, and can prevent high-temperature gas leaking from an impeller side from entering a motor cavity.

Description

Magnetic levitation high-speed centrifuge impeller sealing structure Technical Field

[0001] This utility model relates to the field of centrifuge technology, and in particular to a magnetic levitation high-speed centrifuge impeller sealing structure. Background Technology

[0002] As centrifugal blowers are increasingly replacing traditional Roots blowers and multi-stage centrifugal blowers across various industries, the cooling issues of magnetic levitation motors are becoming increasingly apparent. In the traditional magnetic levitation centrifuge structure, fluid becomes a high-temperature, high-pressure fluid after passing through the impeller. It flows out from the gap between the impeller and the front cover of the motor, passes through the gap between the seal and the impeller, and finally enters the motor cavity through the protective bearing. Due to the high temperature and centrifugal force, the impeller deforms. To prevent damage caused by collisions between the seal and the impeller, the gap between the seal and the impeller is designed to be relatively large, resulting in poor sealing and excessive leakage of high-temperature gas from the impeller side. This leads to overheating of the magnetic levitation bearings and the motor's stator and rotor, causing vibration of the magnetic levitation rotor and ultimately resulting in damage. Utility Model Content

[0003] To overcome the shortcomings of existing technologies, a magnetic levitation high-speed centrifuge impeller sealing structure is provided. This structure solves the problems of poor impeller sealing performance in existing magnetic levitation centrifuge structures, which easily lead to the leakage of a large amount of high-temperature gas from the impeller side into the motor cavity, causing overheating of the magnetic levitation bearings and motor stator and rotor, and causing vibration of the magnetic levitation rotor.

[0004] To achieve the above technical effects, the present invention provides a magnetic levitation high-speed centrifuge impeller sealing structure, which includes:

[0005] An annular seal is installed between the impeller and the front cover of the motor and is sleeved on the rotor. The annular seal has continuous radial sealing teeth along the circumferential direction on the side facing the impeller, and continuous axial sealing teeth are formed on the inner ring wall of the annular seal.

[0006] Impeller sealing teeth are provided on the side of the impeller facing the annular seal. The impeller sealing teeth mesh with the radial sealing teeth. The annular seal, the rotor, and the impeller form a sealing cavity. The annular seal is provided with a first fluid channel communicating with the sealing cavity. The front end cover of the motor is provided with a second fluid channel communicating with the first fluid channel to the outside of the centrifuge.

[0007] Preferably, both the radial sealing teeth and the impeller sealing teeth are helical tooth structures.

[0008] Preferably, the radial sealing teeth are inclined inward.

[0009] Preferably, the axial sealing teeth have a straight tooth structure.

[0010] Preferably, the first fluid channel is a perforation that extends axially through the annular sealing panel.

[0011] Preferably, there are multiple perforations, and the multiple perforations are distributed at intervals along the circumference.

[0012] Preferably, the front end cover of the motor is formed with a groove for accommodating the annular seal, and the second fluid channel includes a slot corresponding to the perforation and disposed at the bottom of the groove, and a radial through hole connecting the slot to the outside of the centrifuge.

[0013] Preferably, there are multiple slots, and the multiple slots are distributed at intervals along the circumference.

[0014] Preferably, there are multiple radial sealing teeth and multiple impeller sealing teeth, with multiple radial sealing teeth arranged coaxially and multiple impeller sealing teeth arranged coaxially, and the number of impeller sealing teeth is not less than the number of radial sealing teeth.

[0015] Preferably, the number of axial sealing teeth is multiple, and the multiple axial sealing teeth are arranged in parallel.

[0016] The beneficial effects of this invention are as follows: The impeller sealing structure of this magnetic levitation high-speed centrifuge employs a toothed radial labyrinth seal structure in the annular seal, which, together with the impeller sealing teeth, forms a trapping structure to increase the resistance to fluid inflow into the motor cavity and reduce the inflow rate. After the airflow passes through the radial seal, the leakage velocity is further reduced, and the leakage rate is significantly decreased. The airflow then flows out of the centrifuge through the first and second fluid channels, while residual gas continues to flow to the axial sealing teeth of the annular seal for sealing, preventing it from flowing into the motor cavity. This invention provides a good seal between the impeller and the gas, effectively preventing high-temperature gas leaking from the impeller side from entering the motor cavity. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is a partial cross-sectional view of the magnetic levitation high-speed centrifuge impeller sealing structure of this utility model installed at the rear of the centrifuge.

[0019] Figure 2 is a schematic diagram of the annular seal of the magnetic levitation high-speed centrifuge impeller sealing structure of this utility model.

[0020] Figure 3 is a schematic diagram of the impeller cross-section structure of the magnetic levitation high-speed centrifuge impeller sealing structure of this utility model.

[0021] Figure 4 is an enlarged schematic diagram of the radial sealing teeth of the annular seal of the magnetic levitation high-speed centrifuge impeller sealing structure of this utility model.

[0022] Figure 5 is an enlarged schematic diagram of the axial sealing teeth of the annular seal of the magnetic levitation high-speed centrifuge impeller sealing structure of this utility model.

[0023] Figure 6 is a schematic diagram of the motor front end cover of the magnetic levitation high-speed centrifuge impeller sealing structure of this utility model.

[0024] The correspondence between the numbers in the diagram is as follows:

[0025] 1-Annular seal; 2-Impeller; 3-Motor front end cover; 301-Groove; 302-Slot; 303-Radial through hole; 4-Rotor; 5-Radial sealing tooth; 6-Axial sealing tooth; 7-Sealing cavity; 8-First fluid channel; 9-Second fluid channel; 10-Impeller sealing tooth. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Please refer to Figures 1 to 6. This embodiment of the invention provides a magnetic levitation high-speed centrifuge impeller sealing structure, including an annular seal 1 and impeller sealing teeth 10. Wherein:

[0028] As shown in Figure 1, the annular seal 1 is installed between the impeller 2 and the front end cover 3 of the motor, and is sleeved on the rotor 4. As shown in Figures 2 and 4, the annular seal 1 has continuous radial sealing teeth 5 formed circumferentially on the side facing the impeller 2, and continuous axial sealing teeth 6 are formed on the inner ring wall of the annular seal 1.

[0029] As shown in Figures 1 and 3, the impeller sealing teeth 10 are located on the side of the impeller 2 facing the annular seal 1, and the impeller sealing teeth 10 mesh with the radial sealing teeth 5. Under the action of the radial sealing teeth 5, the impeller sealing teeth 10, and the axial sealing teeth 6, a sealing cavity 7 is formed between the annular seal 1, the rotor 4, and the impeller 7. The annular seal 1 is provided with a first fluid channel 8 that connects to the sealing cavity, and the motor front end cover 3 is provided with a second fluid channel 9 that connects the first fluid channel 8 to the outside of the centrifuge.

[0030] After flowing through impeller 2, the fluid becomes a high-temperature, high-pressure fluid and flows into the sealing cavity 7 on the back of impeller 2. The radial sealing teeth 5 of the annular seal 1 mesh with the impeller sealing teeth 10 to form a flow-blocking structure, thereby increasing the resistance to the fluid flowing into the motor cavity from the sealing cavity 7 and reducing the inflow rate. After the fluid is cut off by the radial sealing structure formed by the radial sealing teeth 5 and the impeller sealing teeth 10, the leakage velocity is further reduced, and the leakage rate is also significantly reduced. Then, most of the fluid in the sealing cavity 7 flows out of the centrifuge through the first fluid channel 8 and the second fluid channel 9. The residual gas in the sealing cavity 7 continues to flow to the axial sealing teeth 6, which continue to perform a sealing function. The axial sealing teeth 6 can effectively reduce the flow rate of the hot fluid flowing from impeller 2 into the motor cavity and also prevent the fluid inside the motor from entering the impeller 2.

[0031] As a preferred embodiment, as shown in Figures 3 and 4, both the radial sealing tooth 5 and the impeller sealing tooth 10 are helical tooth structures. Preferably, the helical tooth structure is coated with a wear-resistant material. Simulation calculations and measurements show that using helical teeth can minimize the amount of fluid entering the system.

[0032] In a preferred embodiment, the radial sealing teeth 5 are inclined inward, while the corresponding impeller sealing teeth 10 are inclined outward, thereby achieving meshing between the two.

[0033] As a preferred embodiment, as shown in Figure 5, the axial sealing tooth 6 has a straight tooth structure.

[0034] As a preferred embodiment, as shown in Figure 2, the first fluid channel 8 is a perforation that extends axially through the annular seal 1 panel.

[0035] In a preferred embodiment, there are multiple perforations, which are distributed at intervals along the circumference.

[0036] As a preferred embodiment, as shown in Figure 6, the motor front end cover 3 has a groove 301 for accommodating an annular seal. The second fluid channel 9 includes a slot 302 corresponding to the perforation 8 and disposed at the bottom of the groove 301, and a radial through hole 303 connecting the slot 302 to the outside of the centrifuge. The fluid in the sealing cavity 7 flows out of the centrifuge through the perforation 8, the slot 302, and the radial through hole 303, thereby reducing the axial force generated by the airflow and reducing the axial force of the high-power single cantilever unit.

[0037] In a preferred embodiment, there are multiple slots 302, which are distributed at intervals along the circumference.

[0038] In a preferred embodiment, there are multiple radial sealing teeth 5 and multiple impeller sealing teeth 10, with the radial sealing teeth 5 and impeller sealing teeth 10 arranged coaxially, and the number of impeller sealing teeth 10 is not less than the number of radial sealing teeth 5. In this embodiment, there are 5 radial sealing teeth 5 and 7 impeller sealing teeth 10. Calculations and measurements show that the designed number of sealing teeth can maximize the normal operation of the equipment, slow down the leakage rate, and reduce the leakage amount.

[0039] In a preferred embodiment, there are multiple axial sealing teeth 6, arranged in parallel. In this embodiment, there are three axial sealing teeth 6. Since the energy and pressure of the residual gas in the sealing cavity 7 have been significantly reduced, the number of sealing teeth can be appropriately reduced.

[0040] Preferably, a radial clearance of 0.8mm-1.2mm is formed between the radial sealing teeth 5 and the impeller sealing teeth 10. This radial clearance ensures the best possible fit between the two, preventing collisions under both emergency and normal operating conditions, and also ensuring proper installation and reducing leakage. The radial clearance should be as small as possible while preventing friction.

[0041] Preferably, an axial gap is formed between the axial sealing tooth 6 and the rotor 4, and the axial gap is 0.6-0.8mm.

[0042] Furthermore, during normal operation, both the radial and axial clearances are kept smaller than the clearance of the protective bearing to ensure that the magnetic bearing does not collide with the seals and cause seal damage under normal or accident conditions.

[0043] In this invention, the impeller sealing structure of a magnetic levitation high-speed centrifuge transforms fluid into high-temperature, high-pressure fluid after it passes through the impeller 2. The fluid then flows into the sealing cavity 7 on the back of the impeller 2. The radial sealing teeth 5 of the annular seal 1 mesh with the impeller sealing teeth 10 to form a flow-blocking structure, preventing the fluid from flowing into the motor cavity. Simultaneously, most of the fluid in the sealing cavity 7 flows sequentially through the perforation 8, the slot 302, and the radial through-hole 303, exiting the centrifuge. Residual gas in the sealing cavity 7 continues to flow to the axial sealing teeth 6, which continue to provide a seal, thus preventing residual gas from flowing into the motor cavity.

[0044] All parts not described in this utility model are the same as or can be implemented using existing technology. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this utility model, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A sealing structure for the impeller of a magnetically levitated high-speed centrifuge, characterized in that, include: An annular seal is installed between the impeller and the front cover of the motor and is sleeved on the rotor. The annular seal has continuous radial sealing teeth along the circumferential direction on the side facing the impeller, and continuous axial sealing teeth are formed on the inner ring wall of the annular seal. Impeller sealing teeth are provided on the side of the impeller facing the annular seal. The impeller sealing teeth mesh with the radial sealing teeth. The annular seal, the rotor, and the impeller form a sealing cavity. The annular seal is provided with a first fluid channel communicating with the sealing cavity. The front end cover of the motor is provided with a second fluid channel communicating with the first fluid channel to the outside of the centrifuge.

2. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 1, characterized in that, Both the radial sealing teeth and the impeller sealing teeth have a helical tooth structure.

3. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 2, characterized in that, The radial sealing teeth are inclined inward.

4. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 1, characterized in that, The axial sealing teeth have a straight tooth structure.

5. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 1, characterized in that, The first fluid channel is a perforation, which extends axially through the annular sealing panel.

6. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 5, characterized in that, The number of perforations is multiple, and the multiple perforations are distributed at intervals along the circumference.

7. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 5, characterized in that, The front end cover of the motor has a groove for accommodating the annular seal. The second fluid channel includes a slot corresponding to the perforation and disposed on the bottom of the groove, and a radial through hole connecting the slot to the outside of the centrifuge.

8. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 7, characterized in that, The number of slots is multiple, and the multiple slots are distributed at intervals along the circumference.

9. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 1, characterized in that, The radial sealing teeth and the impeller sealing teeth are multiple in number, with multiple radial sealing teeth arranged coaxially and multiple impeller sealing teeth arranged coaxially, and the number of impeller sealing teeth is not less than the number of radial sealing teeth.

10. The magnetic levitation high-speed centrifuge impeller sealing structure as described in claim 1, characterized in that, The number of axial sealing teeth is multiple, and the multiple axial sealing teeth are arranged in parallel.

Images