CN217177410U

CN217177410U - Double-end face integrated sealing device

Info

Publication number: CN217177410U
Application number: CN202123216781.2U
Authority: CN
Inventors: 李平; 励永平; 董军锋; 李少峰; 叶传剑
Original assignee: Ningbo Donglian Mechanical Seal Co ltd
Current assignee: Ningbo Donglian Mechanical Seal Co ltd
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2022-08-12
Anticipated expiration: 2031-12-17

Abstract

The utility model provides a bi-polar face cartridge-type sealing device, including axle sleeve, seal receptacle, main seal and vice seal, the main seal includes active ring subassembly, first corrugated metal pipe, first fixing base and main quiet ring, first fixing base is connected with the one end transmission of axle sleeve, the one end of seal receptacle is equipped with first mounting groove, the equipment that the one end of main quiet ring is sealed is equipped in first mounting groove, the other end of main quiet ring is with the one end butt of active ring subassembly, the other end of active ring subassembly is connected through first corrugated metal pipe seal with the other end of first fixing base; the outer wall of the sealing seat is provided with an outer flushing hole, an inner flushing hole and a plurality of flushing ports communicated with the inner flushing hole; and the outer wall of the driving ring component is provided with a spiral groove. The utility model provides a bi-polar face cartridge-type sealing device, compensation performance is stable, and compensating element is difficult to take place the particulate matter and gather, and corrosion resistance is strong, guarantees stable sealing performance.

Description

Double-end face integrated sealing device

Technical Field

The utility model belongs to the technical field of the mechanical seal technique and specifically relates to a bi-polar face collection dress formula sealing device.

Background

The sealing reliability of the mechanical seal applied to the chemical industry plays an important role in the quality and stability of production. Particularly, in a chemical medium with high solid particle content, easy condensation of materials and strong corrosivity, strong abrasive wear is easily generated on a sealing end face, so that the sealing end face is excessively worn at an early stage to cause material leakage, and the service life of the seal is short; in addition, corrosive media also place higher demands on the corrosion resistance of the parts of the mechanical seal.

In the existing mechanical sealing device, in order to avoid the situation that the compensation part is abraded, stuck or corroded by medium particles, a static ring compensation structure is usually arranged, and most of the compensation elements are small springs which are arranged in the sealing seat in a hidden manner, although the static ring compensation structure can avoid the excessive contact of the compensation elements with media, the structure can also lead the sealing grinding surface to have poor rotation following performance on the rotating shaft, and the leakage risk of the sealing grinding surface is increased; in addition, the static ring compensation type structure needs to be provided with a compensation element, so that the axial size of the sealing seat is increased, and the processing cost and the packaging cost are increased.

SUMMERY OF THE UTILITY MODEL

The utility model provides a problem is, in order to overcome the defect among the prior art, provide a bi-polar face cartridge-type sealing device, compensation performance is stable, and compensating element is difficult to take place the particulate matter and gather, and corrosion resistance is strong, guarantees stable sealing performance.

In order to solve the problems, the utility model provides a double-end-face packaging type sealing device, which comprises a shaft sleeve, wherein a sealing seat, a main seal and an auxiliary seal are sleeved outside the shaft sleeve, one end of the main seal is in transmission connection with one end of the shaft sleeve, the other end of the main seal is assembled with one end of the sealing seat, one end of the auxiliary seal is in transmission connection with the other end of the shaft sleeve, the other end of the auxiliary seal is assembled with the other end of the sealing seat, a sealing cavity is formed among the main seal, the auxiliary seal, the sealing seat and the shaft sleeve, a plurality of limit blocks are detachably connected between the auxiliary seal and the sealing seat, the main seal comprises a driving ring component, a first metal corrugated pipe, a first fixed seat and a main static ring, the first fixed seat is in transmission connection with one end of the shaft sleeve, one end of the sealing seat is provided with a first mounting groove, one end of the main static ring is assembled in the first mounting groove in a sealing way, the other end of the main static ring and one end of the driving ring assembly are abutted and connected in a relatively rotatable mode along the circumferential direction to form a main sealing grinding surface, and the other end of the driving ring assembly is connected with the other end of the first fixed seat in a sealing mode through a first metal corrugated pipe; the outer wall of the sealing seat is provided with an outer flushing hole communicated with the sealing cavity, the sealing seat is also provided with an inner flushing hole, and one end of the sealing seat close to the main seal is provided with a plurality of flushing ports communicated with the inner flushing hole; and the outer wall of the driving ring component is provided with a spiral groove extending along the axial direction of the driving ring component.

Compared with the prior art, the mechanical sealing device of the utility model has the following advantages:

1. sealing device is two terminal surfaces cartridge-type structure, can realize the mounting means that the whole dress was put in order to tear open, and is low to installer's technical requirement, can install fast accurate and target in place, reduces the sealed installation difficulty and solves the mechanical seal probability of failure because of the installation factor causes.

2. The main seal adopts the metal corrugated pipe as an elastic compensation element, has simple structure, stable compensation performance, strong wear resistance and corrosion resistance and good floatability, ensures the stability of the seal and has long service life; in addition, the metal corrugated pipe is arranged at the end of the movable ring, and can absorb the vibration of the equipment along with the synchronous rotation of the rotating shaft, so that the influence of the vibration of the equipment on the sealing effect is reduced.

3. The outer flushing and inner flushing combined structure is characterized in that a cooling liquid can be introduced into the isolation cavity from the outer flushing hole, so that the frictional heat of the sealing grinding surface can be cooled and cooled in time, the thermal deformation of the sealing grinding surface is avoided, the sealing stability is ensured, and the service life is prolonged; through the matching effect of the inner flushing hole and the plurality of flushing ports, the inner flushing liquid can continuously flow to the main sealing position from the plurality of flushing ports, so that the medium around the main seal is ensured to have higher cleanliness, and the abrasion of the main seal, which is aggravated by particles contained in the medium and slurry with high viscosity, is prevented; on the other hand, the spiral groove formed in the outer wall of the driving ring assembly can enhance circulation of media around the main seal, and solid particles in the media are prevented from being accumulated on the grinding surface of the main seal to affect sealing performance.

As an improvement, one end of the shaft sleeve is provided with a convex limit step, the first fixed seat is abutted against the limit step along the axial direction, the outer wall of the first fixed seat is provided with a plurality of transmission screws extending along the radial direction, and the plurality of transmission screws are tightly matched on the outer wall of the shaft sleeve. In the above-mentioned improvement structure, spacing stair structure has strengthened the stability that first fixing base is connected to tight fit through driving screw and axle sleeve realizes that the axle sleeve is connected with the transmission of fixing base, simple structure, easy dismounting.

And the improved structure is characterized in that an insertion hole is formed in the inner wall of one end, close to the main seal, of the shaft sleeve, a transmission sleeve is inserted and matched in the insertion hole, and one end, far away from the shaft sleeve, of the transmission sleeve is in transmission fit with the rotating shaft. In the above-mentioned improvement structure, the transmission of setting up reinforcing axle sleeve and rotation axis of transmission cover structure is connected to step axle construction in the adaptation pump body that can be better.

And the end surface of the transmission sleeve close to one end of the shaft sleeve is provided with a limit groove matched with the limit convex column. In the above-mentioned improvement structure, limit structure's setting has effectively improved the stability that transmission sleeve and axle sleeve rotate to be connected, and then guarantees the stability that axle sleeve and rotation axis transmission are connected.

The auxiliary seal comprises an auxiliary moving ring component, a second metal corrugated pipe, a second fixed seat and an auxiliary static ring, the second fixed seat is in transmission connection with the other end of the shaft sleeve, a second mounting groove is formed in the other end of the seal seat, one end of the auxiliary static ring is hermetically assembled in the second mounting groove, and the other end of the auxiliary static ring and one end of the auxiliary moving ring component can be abutted in a relatively rotatable mode along the circumferential direction to form an auxiliary seal grinding surface; the side wall of the second fixed seat is also provided with a plurality of driving screws arranged along the radial direction, and the end parts of the plurality of driving screws penetrate through the shaft sleeve to be tightly matched with the rotating shaft. In the improved structure, the auxiliary sealing structure also adopts the metal corrugated pipe as an elastic compensation element, so that the compensation performance is stable, the abrasion resistance is strong, the floatability is good, the sealing stability is ensured, and the service life is long; corresponding metal bellows is installed at the movable ring end, and along with rotation axis synchronous revolution, metal bellows can also absorb the vibration of equipment, and then reduces the influence of equipment vibration to sealed effect.

And the opening ends of the first mounting groove and the second mounting groove are respectively provided with an annular clamping groove, and a first check ring for axially limiting the main static ring and a second check ring for axially limiting the auxiliary static ring are respectively arranged in the annular clamping grooves. In the above-mentioned improvement structure, realized main quiet ring, vice quiet ring axial spacing on the seal receptacle through two corresponding retaining rings, prevent to break away from with the seal receptacle, it is also more convenient when sealing device assembles.

In another improvement, a positioning hole communicated to the second mounting groove is formed in the bottom of the first mounting groove, a positioning pin is assembled in the positioning hole, and two ends of the positioning pin extend towards the main static ring and the auxiliary static ring respectively; the main stationary ring is provided with a first positioning groove matched with one end of the positioning pin, and the auxiliary stationary ring is provided with a second positioning groove matched with the other end of the positioning pin. In the improved structure, the anti-rotation positioning of the main static ring and the auxiliary static ring can be realized simultaneously through a complete positioning pin, the limiting structure is simplified, and the stability is ensured.

Drawings

Fig. 1 is a half-section structure diagram of the double-end-face cartridge type sealing device of the present invention.

Fig. 2 is a cross-sectional view of the connection structure of the main stationary ring, the auxiliary stationary ring and the fixing base of the present invention.

Fig. 3 is a sectional view of the main seal structure after the main stationary ring is removed.

Description of reference numerals:

1. a shaft sleeve; 1.1, limiting steps; 1.2, inserting holes; 2. a sealing seat; 2.1, a first mounting groove; 2.2, washing holes outwards; 2.3, inner flushing holes; 2.4, flushing the opening; 2.5, a second mounting groove; 3. a limiting block; 4. an active ring assembly; 4.1, an active ring; 4.2, a first movable ring seat; 4.2.1, a first assembling groove; 5. a first metal bellows; 6. a first fixed seat; 7. a main stationary ring; 7.1, a first positioning groove; 8. a helical groove; 9. a drive screw; 10. a transmission sleeve; 11. an auxiliary rotating ring assembly; 11.1, an auxiliary movable ring; 11.2, a second movable ring seat; 12. a second metal bellows; 13. a second fixed seat; 14. a secondary stationary ring; 14.1, a second positioning groove; 15. a drive screw; 16. an annular neck; 17. a first retainer ring; 18. a second retainer ring; 19. positioning pins; 20. a rotating shaft.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

In the description of the present invention, it should be noted that the terms "outer part", "outer wall", "inner wall", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of description and simplification of the description of the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. In addition, in the description of the present invention, the terms "first" and "second" are used for convenience of description and distinction, and have no specific meaning.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the term "connected" is to be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1 and 2, the utility model provides a double-end-face cartridge-type sealing device, which comprises a shaft sleeve 1, the shaft sleeve 1 is sleeved outside a rotating shaft 20, the shaft sleeve 1 is sleeved with a main seal, a sealing seat 2 and an auxiliary seal in sequence, and one end of the main seal is in transmission connection with one end of the shaft sleeve 1, the other end of the main seal is assembled with one end of the sealing seat 2, one end of the auxiliary seal is in transmission connection with the other end of the shaft sleeve 1, and the other end of the auxiliary seal is assembled with the other end of the sealing seat 2, so that a sealing cavity is formed between the main seal, the auxiliary seal, the sealing seat 2 and the shaft sleeve 1; and in the structure, a plurality of limiting blocks 3 are detachably connected between the auxiliary seal and the seal seat 2, namely, one ends of the limiting blocks 3 are detachably connected with the auxiliary seal assembly, the other ends of the limiting blocks 3 are clamped and matched with the seal seat 2 to realize that the shaft sleeve 1, the main seal, the seal seat 2 and the auxiliary seal are integrally assembled, when the mechanical seal device is subsequently installed in the installation cavity of the pump body, the integral seal device can be installed at one time, the seal device does not need to be assembled on site firstly, and then the seal device is installed, so that the installation efficiency is effectively improved.

In the structure, the main seal comprises a driving ring component 4, a first metal corrugated pipe 5, a first fixed seat 6 and a main static ring 7, the first fixed seat 6 is in transmission connection with one end of a shaft sleeve 1, one end of a seal seat 2 is provided with a first installation groove 2.1, one end of the main static ring 7 is hermetically assembled in the first installation groove 2.1, the other end of the main static ring 7 is abutted against one end of the driving ring component 4 in a circumferential direction in a relatively rotatable manner to form a main seal grinding surface, and the other end of the driving ring component 4 is hermetically connected with the other end of the first fixed seat 6 through the first metal corrugated pipe 5; in addition, in this embodiment, be equipped with the outer washing hole 2.2 with the sealed chamber intercommunication on the outer wall of seal receptacle 2, specifically, outer washing hole 2.2 includes a feed liquor hole and a play liquid hole usually to the outside and the dedicated rinse-system intercommunication in feed liquor hole and play liquid hole are used for leading into the coolant liquid towards the circulation in sealed chamber, in time cool off, the cooling to the frictional heat of sealed mill flour, avoid sealed mill flour to take place thermal deformation, guarantee sealed stability.

On the other hand, the sealing seat 2 is also provided with an inner flushing hole 2.3, and one end of the sealing seat 2 close to the main seal is provided with a plurality of flushing ports 2.4 communicated with the inner flushing hole 2.3; the inlet of the inner flushing hole 2.3 is generally communicated with the inner cavity of the pump body through a corresponding pipeline, namely, medium fluid in the pump cavity is pumped into the inner flushing hole 2.3, and then the periphery of the main seal is quickly flushed through the plurality of flushing ports 2.4, so that the medium around the main seal is ensured to have higher cleanliness, and the abrasion of the main seal, which is aggravated by particles contained in the medium and slurry with high viscosity, is prevented.

On the other hand, the spiral groove 8 extending along the axial direction of the driving ring component 4 is formed in the outer wall of the driving ring component, circulation of a medium around the main seal can be enhanced, and the phenomenon that solid particles in the medium are accumulated on a grinding surface of the main seal to affect the sealing performance is avoided.

In the structure, one end of the shaft sleeve 1 is provided with a convex limiting step 1.1, the first fixed seat 6 is axially abutted against the limiting step 1.1, the outer wall of the first fixed seat 6 is provided with a plurality of transmission screws 9 extending along the radial direction, and the plurality of transmission screws 9 are tightly matched on the outer wall of the shaft sleeve 1. In addition, in order to enhance the transmission connection between the shaft sleeve 1 and the rotating shaft 20 and adapt to a step shaft structure in a pump body, in the embodiment, an insertion hole 1.2 is formed in the inner wall of one end, close to the main seal, of the shaft sleeve 1, a transmission sleeve 10 is inserted and combined in the insertion hole 1.2, and one end, far away from the shaft sleeve 1, of the transmission sleeve 10 is in transmission fit with the rotating shaft 20 through a key connection structure. In the structure, in order to improve the stability of the rotational connection between the transmission sleeve 10 and the shaft sleeve 1, a convex limiting convex column (not shown in the figure) is arranged at the bottom of the insertion hole 1.2, and correspondingly, a limiting groove matched with the limiting convex column is arranged on the end surface of the transmission sleeve 10 close to one end of the shaft sleeve 1.

On the other hand, similar to the main sealing structure, the secondary seal in this embodiment includes a secondary moving ring assembly 11, a second metal bellows 12, a second fixed seat 13 and a secondary stationary ring 14, the second fixed seat 13 is in transmission connection with the other end of the shaft sleeve 1, the other end of the sealing seat 2 is provided with a second mounting groove 2.5, one end of the secondary stationary ring 14 is hermetically assembled in the second mounting groove 2.5, and the other end of the secondary stationary ring 14 and one end of the secondary moving ring assembly 11 can be abutted in a relative rotation manner along the circumferential direction to form a secondary sealing grinding surface; the side wall of the second fixed seat 13 is further provided with a plurality of driving screws 15 arranged along the radial direction, and the end parts of the plurality of driving screws 15 penetrate through the shaft sleeve 1 to be tightly matched with the rotating shaft 20. Specifically, a plurality of avoiding holes for the driving screws 15 to pass through are formed in the side wall of the shaft sleeve 1.

In the above structure, for better ensuring the stability of the main stationary ring 7 and the auxiliary stationary ring 14 assembled on the sealing seat 2, the open ends of the first mounting groove 2.1 and the second mounting groove 2.5 are both provided with the ring-shaped clamping grooves 16, and the two ring-shaped clamping grooves 16 are respectively provided with the first retainer ring 17 for axially limiting the main stationary ring 7 and the second retainer ring 18 for axially limiting the auxiliary stationary ring 14. Specifically, the first retainer ring 17 is abutted and limited on the radial outer side of one end of the main stationary ring 7 far away from the first mounting groove 2.1; the second stop ring 18 abuts and is limited at the radial outer side of one end of the auxiliary static ring 14 far away from the second mounting groove 2.5.

More specifically, as shown in fig. 2, a positioning hole communicated to the second mounting groove 2.5 is formed at the bottom of the first mounting groove 2.1, and a corresponding positioning pin 19 is fitted in the positioning hole, and two ends of the positioning pin 19 extend towards the main stationary ring 7 and the auxiliary stationary ring 14 respectively; and the main stationary ring 7 is provided with a first positioning groove 7.1 matched with one end of the positioning pin 19, and the auxiliary stationary ring 14 is provided with a second positioning groove 14.1 matched with the other end of the positioning pin 19. In the structure, the anti-rotation positioning of the main static ring 7 and the auxiliary static ring 14 can be realized simultaneously through a complete positioning pin 19, the limiting structure is simplified, and the stability is ensured.

In this embodiment, preferably, as shown in fig. 3, the driving ring assembly 4 includes a driving ring 4.1 and a first moving ring seat 4.2, one end of the first moving ring seat 4.2 is provided with a first fitting groove 4.2.1, and one end of the driving ring 4.1, which is far away from the main stationary ring 7, is tightly fitted in the first fitting groove 4.2.1; the other end of the first movable ring seat 4.2 is welded and fixed with one end of the first metal corrugated pipe 5, and the other end of the first metal corrugated pipe 5 is welded and fixed with the first fixed seat 6, so as to form the driving ring component 4. Specifically, the driving ring 4.1 is made of graphite, the main stationary ring 7 is made of silicon carbide, the first movable ring seat 4.2 is made of stainless steel, and the driving ring 4.1 and the first movable ring seat 4.2 are assembled and connected in a hot-insert mode. In addition, the first metal corrugated pipe 5 and the welding parts of the two ends of the first metal corrugated pipe, the first movable ring seat 4.2 and the first fixed seat 6 are sealing structures.

In addition, the structure of the auxiliary rotating ring assembly 11 in this embodiment is substantially the same as that of the driving ring assembly 4, and it also includes an auxiliary rotating ring 11.1 and a second rotating ring seat 11.2, and the second metal corrugated pipe 12 is also welded and fixed with the second fixed seat 13 and the second rotating ring seat 11.2, which is not further described herein. The only difference between this structure and the driving ring assembly 4 is that the second moving ring seat 11.2 is provided with a plurality of circumferentially-respective threaded holes for respectively passing a plurality of driving screws 15.

In addition, in the structure, a first destressing groove 4.2.2 is formed in the position, close to the first metal corrugated pipe 5, on the outer wall of the first movable ring seat 4.2; a second stress relief groove 11.2.1 is formed in the outer wall of the second movable ring seat 11.2 and close to the second metal corrugated pipe 12; and stress deformation can not occur after welding, so that the flatness of the driving ring 4.1 or the auxiliary driving ring 11.1 is influenced, and the sealing performance of the corresponding sealing grinding surface is further ensured.

Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and such changes and modifications will fall within the scope of the present invention.

Claims

1. The utility model provides a bi-polar face collection dress formula sealing device, includes axle sleeve (1), axle sleeve (1) outside cover is equipped with seal receptacle (2), main seal and vice sealed, the one end of main seal is connected with the one end transmission of axle sleeve (1), the other end of main seal is joined in marriage the dress with the one end of seal receptacle (2), vice sealed one end with the other end transmission of axle sleeve (1) is connected, the other end of vice sealed is joined in marriage the dress with the other end of seal receptacle (2), form sealed chamber between main seal, vice sealed, seal receptacle (2) and axle sleeve (1), vice sealed with detachable is connected with a plurality of stopper (3) between seal receptacle (2), its characterized in that: the main seal comprises a driving ring assembly (4), a first metal corrugated pipe (5), a first fixed seat (6) and a main static ring (7), the first fixed seat (6) is in transmission connection with one end of a shaft sleeve (1), one end of the seal seat (2) is provided with a first mounting groove (2.1), one end of the main static ring (7) is hermetically assembled in the first mounting groove (2.1), the other end of the main static ring (7) and one end of the driving ring assembly (4) can be abutted and relatively rotated along the circumferential direction to form a main seal grinding surface, and the other end of the driving ring assembly (4) and the other end of the first fixed seat (6) are in sealing connection through the first metal corrugated pipe (5); an outer flushing hole (2.2) communicated with the sealing cavity is formed in the outer wall of the sealing seat (2), an inner flushing hole (2.3) is further formed in the sealing seat (2), and a plurality of flushing ports (2.4) communicated with the inner flushing hole (2.3) are formed in one end, close to the main seal, of the sealing seat (2); and the outer wall of the driving ring component (4) is provided with a spiral groove (8) extending along the axial direction of the driving ring component.

2. The double-ended cartridge seal of claim 1, wherein: one end of the shaft sleeve (1) is provided with a convex limiting step (1.1), the first fixing seat (6) is axially abutted against the limiting step (1.1), the outer wall of the first fixing seat (6) is provided with a plurality of transmission screws (9) extending along the radial direction, and the plurality of transmission screws (9) are tightly matched on the outer wall of the shaft sleeve (1).

3. The double-ended cartridge seal of claim 1 or 2, wherein: the inner wall of one end, close to the main seal, of the shaft sleeve (1) is provided with an insertion hole (1.2), a transmission sleeve (10) is inserted and assembled in the insertion hole (1.2), and one end, far away from the shaft sleeve (1), of the transmission sleeve (10) is in transmission fit with the rotating shaft (20).

4. The double-ended cartridge seal of claim 3, wherein: the bottom of the insertion hole (1.2) is provided with a convex limiting convex column, and the end surface of the transmission sleeve (10) close to one end of the shaft sleeve (1) is provided with a limiting groove matched with the limiting convex column.

5. The double-ended cartridge seal of claim 1, wherein: the auxiliary seal comprises an auxiliary moving ring assembly (11), a second metal corrugated pipe (12), a second fixed seat (13) and an auxiliary static ring (14), the second fixed seat (13) is in transmission connection with the other end of the shaft sleeve (1), a second mounting groove (2.5) is formed in the other end of the seal seat (2), one end of the auxiliary static ring (14) is hermetically assembled in the second mounting groove (2.5), and the other end of the auxiliary static ring (14) is abutted against one end of the auxiliary moving ring assembly (11) in a manner of relative rotation along the circumferential direction to form an auxiliary seal grinding surface; the side wall of the second fixed seat (13) is also provided with a plurality of driving screws (15) which are arranged along the radial direction, and the end parts of the plurality of driving screws (15) penetrate through the shaft sleeve (1) to be tightly matched with the rotating shaft (20).

6. The double-ended cartridge seal of claim 5, wherein: the open end of first mounting groove (2.1) and second mounting groove (2.5) all is equipped with ring groove (16), two be equipped with respectively in ring groove (16) and be used for the first retaining ring (17) of axial spacing main stationary ring (7) and be used for the second retaining ring (18) of axial spacing vice stationary ring (14).

7. The double-ended cartridge seal of claim 5 or 6, wherein: a positioning hole communicated to the second mounting groove (2.5) is formed in the bottom of the first mounting groove (2.1), a positioning pin (19) is assembled in the positioning hole, and two ends of the positioning pin (19) extend towards the main static ring (7) and the auxiliary static ring (14) respectively; the main stationary ring (7) is provided with a first positioning groove (7.1) matched with one end of the positioning pin (19), and the auxiliary stationary ring (14) is provided with a second positioning groove (14.1) matched with the other end of the positioning pin (19).