CN114838133A

CN114838133A - Mechanical seal

Info

Publication number: CN114838133A
Application number: CN202210618733.6A
Authority: CN
Inventors: 王斌; 王树昕; 仇栋
Original assignee: Ningbo Anmu Sealing Technology Co ltd
Current assignee: Ningbo Anmu Sealing Technology Co ltd
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2022-08-02
Anticipated expiration: 2042-06-01
Also published as: CN114838133B

Abstract

The application relates to a mechanical seal, and belongs to the technical field of sealing structures. The heat-conducting heat exchanger comprises a moving ring assembly and a static ring assembly, wherein the moving ring assembly comprises a moving ring seat sleeved on a rotating shaft and a moving ring arranged on the moving ring seat, and two end surfaces of the moving ring are connected with heat-conducting fins abutted to the rotating shaft; the static ring assembly comprises a static ring seat, a heat conducting shaft sleeve sleeved on the rotating shaft, an elastic compensation part arranged on the static ring seat and a static ring abutted against the elastic compensation part; the static ring is made of polytetrafluoroethylene filled glass fiber and is abutted with the dynamic ring; the static ring assembly, the movable ring and the rotating shaft form a cooling chamber for filling cooling media. The static ring is made of polytetrafluoroethylene filled glass fiber, so that heat is not easy to generate under the condition of quick friction; quiet ring subassembly, rotating ring and pivot form the cooling chamber, fill coolant in the cooling chamber, are the rotating ring and quiet ring cooling through coolant to make the rotating ring and quiet ring friction after generating heat can dispel the heat fast.

Description

Mechanical seal

Technical Field

The application relates to the technical field of sealing structures, in particular to a mechanical seal.

Background

The mechanical seal is a shaft seal device of a rotating machine, and is commonly used in equipment such as centrifugal pumps, centrifuges, reaction kettles, compressors and the like.

Some centrifugal pumps, centrifuges and other equipment are used in low-temperature environments (such as liquid nitrogen and liquid oxygen), so that mechanical seals are also in the low-temperature environments; in a low temperature environment, mechanical seals cannot generate much heat or are otherwise prone to explosion, which makes the conventional mechanical seals more difficult to use in the low temperature environment.

Disclosure of Invention

In order for the mechanical seal to be used in a low temperature environment, the present application provides a mechanical seal.

The application provides a mechanical seal adopts following technical scheme:

a mechanical seal comprises a movable ring assembly and a stationary ring assembly, wherein the movable ring assembly comprises a movable ring seat sleeved on a rotating shaft and a movable ring arranged on the movable ring seat, and two end faces of the movable ring are connected with heat-conducting fins abutted to the rotating shaft; the static ring assembly comprises a static ring seat, a heat conducting shaft sleeve sleeved on the rotating shaft, an elastic compensation part arranged on the static ring seat and a static ring abutted against the elastic compensation part;

the static ring is made of polytetrafluoroethylene filled glass fiber and is abutted with the dynamic ring; the static ring assembly, the movable ring and the rotating shaft form a cooling chamber for filling cooling media.

By adopting the technical scheme, firstly, when the mechanical seal is used, the movable ring and the static ring can generate heat by friction, and the static ring is made of the PTFE filled glass fiber, so that the static ring is not easy to generate heat under the condition of quick friction; secondly, quiet ring subassembly, rotating ring and pivot form the cooling chamber, fill coolant in the cooling chamber, are the rotating ring and quiet ring cooling through coolant to can dispel the heat fast after making rotating ring and quiet ring friction generate heat. The mechanical seal integrally generates less heat through the two modes, so that the mechanical seal can be used in a low-temperature environment.

Optionally, the stationary ring seat is connected with a cooling element exchanged with a cooling medium in the cooling chamber, the cooling element has an accommodating chamber for accommodating the cooling medium, and the stationary ring assembly is provided with a trigger element for communicating the accommodating chamber with the cooling chamber.

By adopting the technical scheme, the cooling medium in the cooling part is exchanged with the cooling medium in the accommodating cavity through the trigger part; in actual use, when the stationary ring wears to a certain degree, the cooling medium temperature that holds the intracavity this moment is higher, through the action of trigger part, makes the cooling medium in the cooling part and the cooling medium who holds the intracavity take place the exchange to reduce and hold the intracavity cooling medium's temperature, thereby make the cooling medium can absorb more heat.

Optionally, the trigger part is including sliding and wearing to locate the carriage release lever of heat conduction axle sleeve, the cooling part is seted up and is held the liquid outlet that the chamber is linked together, the cooling part is provided with the stopper that is used for sealing the liquid outlet, the one end and the elastic compensation piece of carriage release lever are connected, and the other end is connected with the stopper.

By adopting the technical scheme, when the static ring is abraded, the elastic compensation part can push the static ring to move towards the direction close to the dynamic ring, so that the dynamic ring and the static ring are always abutted; when the static ring is worn, the elastic compensation part moves, the movable rod moves along with the elastic compensation part, and the plug also moves along with the movable rod.

Optionally, the plug is a magnet, and the plug and the moving rod attract each other.

Through adopting above-mentioned technical scheme, through magnetite and carriage release lever attraction for the carriage release lever can drive the stopper and remove, also makes things convenient for carriage release lever and stopper disconnection simultaneously.

Optionally, the stationary ring assembly is provided with an exchange hole through which a cooling medium of the cooling member enters the cooling chamber, and the moving rod is sleeved with an abutting ring for covering the exchange hole.

By adopting the technical scheme, the cooling medium of the cooling piece enters the accommodating cavity through the exchange hole; in the initial state, the exchange hole is covered by the abutting ring, and after the movable rod moves, the abutting ring also moves along with the movable rod, so that the exchange hole is opened, and the cooling medium in the cooling piece can enter the accommodating cavity through the exchange hole.

Optionally, the triggering element further includes a limiting block connected to the elastic compensation element and a return spring for driving the moving rod to move toward the cooling element, the elastic compensation element is provided with a limiting groove, the limiting block is disposed in the limiting groove, one end of the moving rod away from the cooling element is provided with a flexible pull wire, and one end of the flexible pull wire away from the moving rod is connected to the limiting block; the reset spring is sleeved on the moving rod, one end of the reset spring is abutted to the heat conduction shaft sleeve, and the other end of the reset spring is abutted to the abutting ring.

Through adopting above-mentioned technical scheme, under the initial condition, reset spring and butt ring looks butt, compress tightly the butt ring through reset spring, make the butt ring cover the exchange hole more stable, stopper part exposes the spacing groove simultaneously, and after elastic compensation spare promoted quiet ring to the direction removal that is close to the rotating ring, the stopper also removed along with elastic compensation spare together for the stopper drives the carriage release lever and moves on the heat conduction axle sleeve.

When quiet ring wearing and tearing more back, the stopper is followed the spacing inslot roll-off, and the carriage release lever loses the location of stopper for the carriage release lever removes to the direction that is close to the cooling part under reset spring's effect, thereby makes the stopper reinsert the liquid outlet, plugs up the liquid outlet through the stopper, breaks off the cooling cavity and holds the intercommunication in chamber, makes the cooling part can follow and tears down on the quiet ring unit spare.

Optionally, the stationary ring seat is provided with an embedded groove for embedding the cooling piece.

Through adopting above-mentioned technical scheme, through the cooling part embedding inlay inslot for the cooling part is connected stably with the quiet ring seat.

Optionally, the cooling element is provided with a plurality of positioning notches, the groove wall of the embedding groove is provided with positioning grooves corresponding to the positioning notches, and positioning pins entering the positioning notches are inserted into the positioning grooves.

Through adopting above-mentioned technical scheme, insert location breach and constant head tank through the locating pin in, make the cooling part be difficult for rotating on quiet ring seat to also make the cooling part be connected more stably with quiet ring seat.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the static ring is made of polytetrafluoroethylene filled glass fiber, so that heat is not easy to generate under the condition of quick friction; the static ring assembly, the moving ring and the rotating shaft form a cooling cavity, a cooling medium is filled in the cooling cavity, and the moving ring and the static ring are cooled through the cooling medium, so that the moving ring and the static ring can be rapidly cooled after friction heating;

2. when the static ring is worn, the elastic compensation part can push the static ring to move towards the direction close to the dynamic ring, so that the dynamic ring and the static ring are always abutted; when the static ring is worn, the elastic compensation part moves, the movable rod moves along with the elastic compensation part, and the plug also moves along with the movable rod.

Drawings

FIG. 1 is a cross-sectional view of a mechanical seal according to an embodiment of the present application.

Fig. 2 is an enlarged view at a in fig. 1.

Fig. 3 is an enlarged view at B in fig. 1.

FIG. 4 is a schematic structural diagram of the cooling element and stationary ring assembly after installation according to the embodiment of the present application.

Description of reference numerals: 1. a rotating ring assembly; 11. a movable ring seat; 12. a moving ring; 13. a heat conductive sheet; 14. a compression screw; 2. a stationary ring assembly; 21. a stationary ring seat; 22. a stationary ring; 23. an elastic compensation member; 231. a first metal ring; 232. a metal bellows; 233. a second metal ring; 234. mounting grooves; 235. an O-shaped ring; 236. sealing the ring groove; 24. a heat conducting shaft sleeve; 25. a baffle plate; 251. an exchange well; 26. a cooling chamber; 27. a limiting groove; 28. embedding a groove; 281. positioning a groove; 29. positioning pins; 3. a cooling member; 31. an accommodating chamber; 32. a liquid outlet; 33. a plug; 34. positioning the notch; 4. a trigger; 41. a limiting block; 42. a travel bar; 421. a flexible pull wire; 422. a butting ring; 43. a return spring; 5. a rotating shaft.

Detailed Description

The present application is described in further detail below with reference to figures 1-4.

The embodiment of the application discloses mechanical seal, mechanical seal is used for installing on pivot 5, and is arranged in low temperature environment such as liquid oxygen, liquid nitrogen.

Referring to fig. 1, the mechanical seal includes a moving ring assembly 1 and a stationary ring assembly 2, the moving ring assembly 1 includes a moving ring seat 11 and a moving ring 12, the moving ring seat 11 and the moving ring 12 are both fixedly sleeved on a rotating shaft 5, the moving ring seat 11 is abutted to the moving ring 12, a compression screw 14 for compressing the moving ring 12 is inserted into the moving ring seat 11, the compression screw 14 penetrates into the moving ring 12, and the moving ring 12 is not easy to move on the rotating shaft 5 through the compression screw 14.

And, the both ends face of rotating ring 12 all is connected with conducting strip 13, and conducting strip 13 is the heat-conducting material and makes, and conducting strip 13 and pivot 5 looks butt, transmits the heat on rotating ring 12 into pivot 5 through conducting strip 13, and the rethread pivot 5 is derived. The thermally conductive sheet 13 is made of red copper having good thermal conductivity in this embodiment.

The static ring assembly 2 comprises a static ring seat 21, a static ring 22, an elastic compensation part 23 and a heat conduction shaft sleeve 24, wherein the static ring 22 is made of polytetrafluoroethylene filled glass fiber, so that heat is not easy to generate under the condition of quick friction; the heat-conducting shaft sleeve 24 is made of bronze with good heat-conducting property; the elastic compensation part 23 is connected to the stationary ring seat 21, and the stationary ring 22 and the heat-conducting shaft sleeve 24 are both connected to the elastic compensation part 23.

The elastic compensating element 23 is a metal bellows assembly, the elastic compensating element 23 includes a first metal ring 231, a second metal ring 233 and a metal bellows 232, the metal bellows 232 is located between the first metal ring 231 and the second metal ring 233, and two ends of the metal bellows 232 are respectively fixedly connected to the first metal ring 231 and the second metal ring 233.

The elastic compensation element 23 is inserted into the stationary ring seat 21, and the second metal ring 233 is fixedly connected with the stationary ring seat 21 by laser welding, so that the second metal ring 233 and the stationary ring seat 21 keep stationary. The heat-conducting shaft sleeve 24 is inserted into the elastic compensation element 23, and the heat-conducting shaft sleeve 24 is fixedly connected with the second metal ring 233, so that the heat-conducting shaft sleeve 24 and the second metal ring 233 are kept still.

Referring to fig. 1 and 2, the first metal ring 231 is provided with an installation groove 234, the stationary ring 22 is installed in the installation groove 234, and an outer ring of the stationary ring 22 abuts against the stationary ring seat 21; when the mechanical seal is used, the first metal ring 231 moves towards the direction close to the moving ring 12 all the time under the action of the metal bellows 232, the first metal ring 231 drives the static ring 22 to move, so that the static ring 22 on the first metal ring 231 is abutted to the moving ring 12, and when the rotating shaft 5 rotates, the static ring 22 and the moving ring 12 form a dynamic friction pair.

In order to improve the sealing performance between the first metal ring 231 and the stationary ring 22, a sealing ring groove 236 is formed at the bottom of the mounting groove 234, and an O-ring 235 is mounted in the sealing ring groove 236 of the first metal ring 231.

Because the mechanical seal is used in a low-temperature environment, in order to improve the heat dissipation of the mechanical seal, a cooling medium is filled in the mechanical seal, and the mechanical seal is cooled through the cooling medium. Specifically, the fixed ring seat 21 is fixedly connected with a blocking piece 25, the heat-conducting shaft sleeve 24, the first metal ring 231, the fixed ring 22, the moving ring 12, the rotating shaft 5 and the blocking piece 25 enclose a cooling chamber 26, a cooling medium is located in the cooling chamber 26, and the cooling medium is in contact with the moving ring 12 and the fixed ring 22, so that the cooling medium absorbs heat on the moving ring 12 and the fixed ring 22.

Further, the stationary ring seat 21 is connected with a cooling member 3, the cooling member 3 is provided with an accommodating cavity 31 inside, and a cooling medium is contained in the accommodating cavity 31, the cooling member 3 may be annular or block-shaped, and any cooling member that can be connected with the stationary ring seat 21 and can contain the cooling medium may be connected conveniently, in this embodiment, the cooling member 3 is annular; the static ring component 2 is provided with a plurality of trigger parts 4, the trigger parts 4 are arranged around the rotating shaft 5 at intervals, and the accommodating cavity 31 is communicated with the cooling cavity 26 through the trigger parts 4; after the mechanical seal is used for a period of time, the trigger 4 is actuated, and the trigger 4 connects the accommodating cavity 31 with the cooling chamber 26, so that the cooling medium in the accommodating cavity 31 is exchanged with the cooling medium in the cooling chamber 26.

Referring to fig. 1, 2 and 3, the triggering member 4 includes a stopper 41 and a moving rod 42, the stopper 41 is connected to the first metal ring 231; the moving rod 42 is slidably disposed through the heat conducting shaft sleeve 24, so that the moving rod 42 can slide on the heat conducting shaft sleeve 24, a flexible pull wire 421 is disposed at one end of the moving rod 42, one end of the flexible pull wire 421, which is far away from the moving rod 42, is connected to the limiting block 41, and the other end of the moving rod 42 is connected to the cooling element 3. When the mechanical seal is used, the stationary ring 22 is worn, after the stationary ring 22 is worn, the metal corrugated pipe 232 pushes the first metal ring 231 to move towards the direction close to the moving ring 12, so that the stationary ring 22 is always abutted to the moving ring 12, at the moment, the first metal ring 231 is moved with the heat-conducting shaft sleeve 24, the limiting block 41 is moved together with the first metal ring 231, so that the limiting block 41 drives the moving rod 42 to slide on the heat-conducting shaft sleeve 24, and further, the moving rod 42 opens the cooling part 3, the accommodating cavity 31 is communicated with the cooling cavity 26, and the cooling medium in the accommodating cavity 31 is exchanged with the cooling medium in the cooling cavity 26.

Furthermore, the blocking piece 25 is provided with an exchange hole 251, and the moving rod 42 is slidably arranged in the exchange hole 251; the cooling element 3 is provided with a liquid outlet 32, the liquid outlet 32 corresponds to the exchanging hole 251, so that after the cooling element 3 abuts against the baffle 25, the liquid outlet 32 is communicated with the accommodating cavity 31 through the exchanging hole 251, so that the cooling medium in the accommodating cavity 31 can flow into the cooling cavity 26 from the liquid outlet 32. The cooling element 3 is provided with a plug 33 at the liquid outlet 32, and the liquid outlet 32 is blocked by the plug 33, so that the cooling medium in the accommodating cavity 31 is not easy to flow out from the liquid outlet 32.

The plug 33 is in the shape of a circular truncated cone, the plug 33 is made of a magnet, and the moving rod 42 is made of a magnetic metal such as iron, cobalt, or nickel, so that the plug 33 can attract the moving rod 42. When the device is used, the moving rod 42 penetrates into the exchanging hole 251, the end part of the moving rod 42 is abutted with the plug 33, the plug 33 is connected with the moving rod 42 by the magnetic force of the magnet, and the plug 33 blocks the liquid outlet 32; when the mechanical seal is used for a while, the stationary ring 22 is worn, and the moving rod 42 drives the plug 33 to move away from the cooling element 3, so that the plug 33 is pulled out from the liquid outlet 32, and the cooling medium in the accommodating chamber 31 enters the cooling chamber 26 through the liquid outlet 32 and the exchange hole 251, so that the cooling medium in the accommodating chamber 31 is exchanged with the cooling medium in the cooling chamber 26.

The trigger 4 further comprises a return spring 43, the return spring 43 is sleeved at one end, close to the cooling part 3, of the moving rod 42, the moving rod 42 is fixedly sleeved with a butting ring 422, one end of the return spring 43 is abutted to the heat conducting shaft sleeve 24, the other end of the return spring is abutted to the butting ring 422, the moving rod 42 is always enabled to have a trend of moving towards the cooling part 3 through the return spring 43, and the diameter of the butting ring 422 is larger than the diameter of the exchange hole 251. In the initial state, the abutment ring 422 abuts against the baffle 25, the abutment ring 422 covers the exchange hole 251, and the return spring 43 presses the abutment ring 422 against the baffle 25, so that the cooling medium in the cooling chamber 26 is not easily discharged from the exchange hole 251.

In addition, the first metal ring 231 is provided with a limiting groove 27, and the limiting block 41 is installed in the limiting groove 27; in an initial state, the first metal ring 231 only exposes a part of the limiting groove 27, the first metal ring 231 presses the limiting block 41 against the heat-conducting shaft sleeve 24, and when the first metal ring 231 pushes the stationary ring 22 to move in a direction close to the movable ring 12, the limiting block 41 moves together with the first metal ring 231, so that the limiting block 41 drives the movable rod 42 to slide on the heat-conducting shaft sleeve 24; when the stationary ring 22 is worn more, the moving distance of the first metal ring 231 is longer, so that the limiting groove 27 is completely exposed, the limiting block 41 slides out of the limiting groove 27 under the pulling of the moving rod 42, so that the limiting groove 27 is communicated with the cooling chamber 26, the volume of the cooling chamber 26 is enlarged, and the pressure of the cooling chamber 26 is released; and because of the movement of the stopper 41, the moving rod 42 loses the fixation of the stopper 41, and the moving rod 42 moves towards the direction close to the cooling member 3 under the action of the return spring 43, so that the plug 33 connected with the moving rod 42 is inserted into the liquid outlet 32 again, the liquid outlet 32 is blocked by the plug 33, the communication between the cooling chamber 26 and the accommodating cavity 31 is disconnected, and the cooling member 3 can be detached from the stationary ring assembly 2.

In order to enable the cooling element 3 to be removed from the stationary ring assembly 2, the cooling element 3 is rotatably connected to the stationary ring carrier 21. The stationary ring seat 21 is provided with an embedded groove 28 into which the cooling member 3 is embedded, the cooling member 3 is embedded into the embedded groove 28, and the cooling member 3 can rotate in the embedded groove 28 around the rotating shaft 5.

Referring to fig. 4, in addition, a plurality of positioning notches 34 are formed in the outer circumferential surface of the cooling element 3, and the plurality of positioning notches 34 are arranged at intervals on the circumferential side wall of the cooling element 3; correspondingly, a plurality of positioning grooves 281 are formed in the groove wall of the embedding groove 28, the plurality of positioning grooves 281 correspond to the plurality of positioning notches 34, and in the embodiment, three positioning notches 34 and three positioning grooves 281 are formed; a positioning pin 29 is inserted into the positioning groove 281, and the cooling element 3 is not easy to fall off from the stationary ring seat 21 through the positioning pin 29; in this embodiment, three triggering members 4 are provided, three triggering members 4 correspond to three positioning grooves 281 one by one, and after the positioning grooves 281 correspond to the positioning notches 34, the liquid outlets 32 correspond to the exchange ports.

When the cooling piece 3 is connected with the stationary ring seat 21, the cooling piece 3 is embedded into the embedded groove 28, so that the three positioning notches 34 correspond to the three positioning grooves 281, each positioning notch 34 is communicated with one positioning groove 281, the moving rod 42 corresponds to and abuts against the plug 33 at the moment, then the positioning pin 29 is inserted into the cooling groove, the positioning pin 29 is inserted into the positioning grooves 281 and the positioning notches 34, so that the cooling piece 3 is not easy to rotate on the stationary ring seat 21, and the cooling piece 3 is not easy to fall off from the stationary ring seat 21.

The implementation principle of a mechanical seal in the embodiment of the application is as follows: when the mechanical seal is used, the stationary ring 22 abuts against the moving ring 12, after the stationary ring 22 is worn, the first metal ring 231 pushes the stationary ring 22 to move towards the direction close to the moving ring 12, so that the moving rod 42 also moves towards the direction close to the moving ring 12, after the stationary ring 22 is worn to a certain extent, the plug 33 is pulled out from the liquid outlet 32, and the cooling medium in the cooling part 3 is exchanged with the cooling medium in the cooling chamber 26 through the liquid outlet 32 and the exchange port; when the static ring 22 is worn to a greater extent, the stopper 41 falls off from the stopper groove 27, the moving rod 42 drives the plug 33 to move toward the cooling element 3 under the action of the return spring 43, so that the plug 33 blocks the liquid outlet 32, the abutting ring 422 covers the exchanging hole 251, and the accommodating cavity 31 is not communicated with the cooling chamber 26.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A mechanical seal, characterized by: the heat-conducting type rotating shaft comprises a moving ring assembly (1) and a static ring assembly (2), wherein the moving ring assembly (1) comprises a moving ring seat (11) which is sleeved on a rotating shaft (5) and a moving ring (12) which is arranged on the moving ring seat (11), and two end faces of the moving ring (12) are connected with heat-conducting fins (13) which are used for being abutted to the rotating shaft (5); the static ring assembly (2) comprises a static ring seat (21), a heat-conducting shaft sleeve (24) sleeved on the rotating shaft (5), an elastic compensation piece (23) arranged on the static ring seat (21) and a static ring (22) abutted against the elastic compensation piece (23);

the static ring (22) is made of PTFE (polytetrafluoroethylene) filled glass fiber, and the static ring (22) is abutted with the dynamic ring (12); the static ring component (2), the dynamic ring (12) and the rotating shaft (5) form a cooling chamber (26) for filling cooling medium.

2. A mechanical seal according to claim 1, wherein: the static ring seat (21) is connected with a cooling piece (3) which is exchanged with a cooling medium in the cooling chamber (26), the cooling piece (3) is provided with an accommodating cavity (31) for accommodating the cooling medium, and the static ring component (2) is provided with a trigger piece (4) which enables the accommodating cavity (31) to be communicated with the cooling chamber (26).

3. A mechanical seal according to claim 2, wherein: trigger piece (4) including sliding and wear to locate shift lever (42) of heat conduction axle sleeve (24), liquid outlet (32) that are linked together with holding chamber (31) are seted up in cooling piece (3), cooling piece (3) are provided with stopper (33) that are used for sealing liquid outlet (32), the one end and the elasticity compensation piece (23) of shift lever (42) are connected, and the other end is connected with stopper (33).

4. A mechanical seal according to claim 3, wherein: the plug (33) is a magnet, and the plug (33) and the moving rod (42) are mutually attracted.

5. A mechanical seal according to claim 3, wherein: the static ring component (2) is provided with an exchange hole (251) for allowing a cooling medium of the cooling piece (3) to enter the cooling chamber (26), and the moving rod (42) is sleeved with an abutting ring (422) for covering the exchange hole (251).

6. A mechanical seal according to claim 3, wherein: the trigger piece (4) further comprises a limiting block (41) connected with the elastic compensation piece (23) and a reset spring (43) driving the moving rod (42) to move towards the direction close to the cooling piece (3), the elastic compensation piece (23) is provided with a limiting groove (27), the limiting block (41) is arranged in the limiting groove (27), one end, far away from the cooling piece (3), of the moving rod (42) is provided with a flexible pull wire (421), and one end, far away from the moving rod (42), of the flexible pull wire (421) is connected with the limiting block (41); the reset spring (43) is sleeved on the moving rod (42), one end of the reset spring (43) is abutted with the heat conduction shaft sleeve (24), and the other end of the reset spring is abutted with the abutting ring (422).

7. A mechanical seal according to claim 1, wherein: the static ring seat (21) is provided with an embedded groove (28) for embedding the cooling piece (3).

8. A mechanical seal according to claim 7, wherein: the cooling piece (3) is provided with a plurality of positioning notches (34), the groove wall of the embedded groove (28) is provided with a positioning groove (281) corresponding to the positioning notches (34), and a positioning pin (29) entering the positioning notches (34) is inserted into the positioning groove (281).