Mechanical seal structure of nuclear primary pump

Abstract

The application discloses a nuclear main pump mechanical seal structure and relates to the technical field of nuclear main pump sealing.The application comprises a main shaft and a shell and further comprises a dynamic ring, which is sleeved on the main shaft and rotates synchronously with the main shaft, a gap is left between the circumferential side of the dynamic ring and the shell, one end of the dynamic ring is a contact surface, a lubricating space is arranged on the contact surface, a static ring is sealingly and slidingly installed on the shell, the dynamic ring is coaxial with the static ring and the main shaft penetrates through the static ring, and a gap is left between the inner side of the static ring and the main shaft.The application can effectively smear the lubricating liquid between the dynamic ring and the static ring when the nuclear main pump is running, the main shaft is continuously rotating and the main shaft rotation has a certain amplitude process, the frictional resistance between the dynamic ring and the static ring is reduced, the use effect of the dynamic ring and the static ring is improved, the abrasion degree between the dynamic ring and the static ring is reduced, the dynamic ring and the static ring are avoided from being frequently replaced, and the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nuclear main pump sealing, in particular to a mechanical sealing structure of a nuclear main pump. BACKGROUND

[0002] The nuclear main pump is one of the key equipment of a nuclear power plant, and the sealing performance of the main shaft of the nuclear main pump is directly related to the safe operation of the nuclear power plant. The existing nuclear main pump main shaft sealing technology mainly adopts a mechanical sealing structure, and the friction pair of a dynamic ring arranged on the main shaft sleeve and a static ring arranged on the shell is used to realize rotary sealing. However, this sealing mode has some problems in a long-time operation process.

[0003] Firstly, since the working environment of the nuclear main pump is usually harsh, the medium has the characteristics of high temperature, high pressure and radioactivity, and the friction between the dynamic ring and the static ring can cause severe wear. This wear not only reduces the sealing effect, but also can cause leakage of radioactive medium, causing serious harm to the environment and equipment. Secondly, the dynamic ring and the static ring need to be disassembled and replaced after being used for a period of time due to severe wear, which increases the maintenance cost.

[0004] Therefore, the application provides a mechanical sealing structure of a nuclear main pump. SUMMARY

[0005] The application aims to solve the problems in the background art, and provides a mechanical sealing structure of a nuclear main pump.

[0006] In order to achieve the above-mentioned purpose, the application specifically adopts the following technical scheme:

[0007] The mechanical sealing structure of the nuclear main pump comprises a main shaft and a shell, and further comprises:

[0008] The dynamic ring is sleeved on the main shaft and rotates synchronously with the main shaft, a gap is left between the circumferential side of the dynamic ring and the shell, one end of the dynamic ring is a contact surface, and a lubricating space is arranged on the contact surface of the dynamic ring;

[0009] The static ring is sealingly and slidingly installed on the shell, the dynamic ring is coaxial with the static ring, and the main shaft penetrates through the static ring, and a gap is left between the inner side of the static ring and the main shaft;

[0010] The sealing end cover is installed on the shell, one end of the main shaft penetrates through the sealing end cover, a contact spring is installed between the sealing end cover and the static ring, the contact spring is used to provide elastic contact force in the axial direction of the static ring, and one end of the static ring is in contact with the contact surface of the dynamic ring;

[0011] The oil circulation mechanism is installed on the shell and forms a lubricating oil path with the lubricating space, and lubricating oil is continuously provided to the lubricating space in a trickle form.

[0012] Further, a convex ring is arranged on the contact surface of the moving ring, and a plurality of arc-shaped convex plates are arranged in the convex ring and in a circular array around the axis of the moving ring to form the lubricating space, a gap is left between each arc-shaped convex plate, and the number of turns is not less than two, the arc-shaped convex plates of adjacent turns are staggered, and the convex ring is flush with the end surface of the arc-shaped convex plate.

[0013] Further, two oil supply holes are arranged in the circular array of the end surface of the static ring, one end of the oil supply hole away from the moving ring is arranged with a pipe, the pipe is horizontally and slidingly arranged on the sealing end cover, two circulating oil paths are symmetrically arranged on the sealing end cover, the two pipes are respectively communicated with the two circulating oil paths, and the oil circulating mechanism is communicated with the two circulating oil paths.

[0014] Further, the oil circulating mechanism comprises an oil box arranged on the shell, and oil supply pipes are communicated with the upper end and the lower end of one side of the oil box, the two oil supply pipes are respectively communicated with the two circulating oil paths, one of the oil supply pipes is arranged with a power member, and the power member is used to supply the lubricating oil in the oil box to the corresponding oil supply pipe.

[0015] Further, the power member comprises a mounting cylinder arranged on the shell, an elastic sliding touch rod is arranged at one end of the mounting cylinder, the free end of the touch rod abuts against the outer circumferential side of the moving ring, when the moving ring has a small amplitude in rotation, the touch rod moves vertically with a small amplitude, a conversion mechanism is arranged on the mounting cylinder and communicated with the oil supply pipe, when the touch rod moves, the conversion mechanism is used to convert the moving power of the touch rod into the oil transmission force.

[0016] Further, the conversion mechanism comprises a mounting box communicated with the oil supply pipe, transmission gears are rotatably arranged in the mounting box, one of the transmission gears is arranged with a rotating cylinder outside the rotating shaft, a driving plate is rotatably arranged in the mounting cylinder, a wedge-shaped plate is vertically and elastically slidingly arranged at the top end of the driving plate, a plurality of wedge-shaped grooves are arranged in a circular array at the bottom end of the rotating cylinder and used for inserting the wedge-shaped plate, the wedge-shaped grooves form an annular clamping groove at the bottom of the rotating cylinder, and the driving plate is connected with the touch rod.

[0017] Further, an execution rod is vertically and slidingly arranged in the mounting cylinder, a conversion hole is arranged at the axis of the driving plate, a spiral groove is annularly arranged on the inner circumferential side of the conversion hole, a guide plate is arranged on the outer side of the execution rod and located in the spiral groove, and the execution rod is non-contact transmission connected with the touch rod, when the touch rod moves with a small amplitude, the execution rod moves with a large amplitude compared with the touch rod.

[0018] Further, the installation cylinder is slidably installed with an abutting plate, an abutting spring is installed between the abutting plate and the installation cylinder, one end of the abutting plate abuts against one end of the triggering lever, a connecting lever is coaxially arranged on the abutting plate, and the connecting lever is non-contact transmission connected with the executing lever.

[0019] Further, the installation cylinder has a small-diameter cavity and a large-diameter cavity, the executing lever is slidably inserted into the small-diameter cavity, the connecting lever is arranged with a pushing plate in the large-diameter cavity away from one end of the triggering lever, and the large-diameter cavity and the small-diameter cavity are in communication, and a sealed area is formed between the pushing plate and the executing lever.

[0020] Further, one end of the triggering lever is an outer arc surface, the oil box is annular, two filter plates are installed in the oil box, and the two filter plates divide the oil box into two areas.

[0021] The beneficial effects of the present application are as follows:

[0022] The present application effectively applies lubricating liquid between the dynamic ring and the static ring during the continuous rotation of the main shaft and the rotation of the main shaft with a certain amplitude when the nuclear main pump is running, reduces the frictional resistance between the dynamic ring and the static ring, improves the use effect of the dynamic ring and the static ring, reduces the abrasion degree between the dynamic ring and the static ring, avoids frequent replacement of the dynamic ring and the static ring, and reduces the maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the three-dimensional structure of the present application;

[0024] Figure 2 is a schematic diagram of the three-dimensional structure of the present application Figure 1 partial cross-sectional view Figure 1 ;

[0025] Figure 3 is a schematic diagram of the three-dimensional structure of the present application Figure 1 partial cross-sectional view Figure 2 ;

[0026] Figure 4 is a schematic diagram of the three-dimensional structure of the present application Figure 1 partial cross-sectional view Figure 3 ;

[0027] Figure 5 is a schematic diagram of the three-dimensional structure of the present application Figure 1 partial cross-sectional view Figure 4 ;

[0028] Figure 6 is a schematic diagram of the three-dimensional structure of the present application

[0029] Figure 7 is a schematic diagram of the three-dimensional structure of the present application

[0030] Figure 8is the exploded view of the installation cylinder structure of the present application;

[0031] Figure 9 is the exploded view of the installation cylinder structure of the present application Figure 8 partial another perspective view;

[0032] Figure 10 is the exploded view of the installation cylinder structure of the present application Figure 2 structure enlarged view at A in the present application;

[0033] Figure 11 is the exploded view of the installation cylinder structure of the present application Figure 2 structure enlarged view at B in the present application;

[0034] Figure 12 is the exploded view of the installation cylinder structure of the present application Figure 3 structure enlarged view at C in the present application.

[0035] Reference signs: 1, moving ring; 2, main shaft; 3, outer shell; 4, static ring; 5, sealing end cover; 6, abutting spring; 7, oil circulation mechanism; 701, oil box; 702, oil delivery pipe; 8, convex ring; 9, arc convex plate; 10, oil delivery hole; 11, insertion pipe; 12, circulating oil way; 13, pushing plate; 14, power piece; 1401, installation cylinder; 1402, touching rod; 15, conversion mechanism; 1501, installation box; 1502, transmission gear; 1503, rotating cylinder; 1504, driving plate; 1505, wedge plate; 1506, wedge-shaped groove; 16, execution rod; 17, conversion hole; 18, helical groove; 19, guide plate; 20, abutting plate; 21, abutting spring; 22, connecting rod; 23, small-diameter cavity; 24, large-diameter cavity; 25, filter plate. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0037] As Figures 1-12 shown, the mechanical seal structure of the nuclear main pump provided by one embodiment of the present application comprises a main shaft 2 and an outer shell 3, and the partial structure of the main shaft 2 and the outer shell 3 shown in the figure further comprises:

[0038] a moving ring 1 sleeved on the main shaft 2 and synchronously rotating with the main shaft 2, a gap being left between the peripheral side of the moving ring 1 and the outer shell 3, the gap between the moving ring 1 and the outer shell 3 being able to effectively prevent the case that the outer side of the main shaft 2 or the moving ring 1 is damaged due to hard interference caused by vibration and deviation of the existing nuclear main pump during high-speed operation, one end of the moving ring 1 being a contact surface, and a lubrication space being provided on the contact surface of the moving ring 1;

[0039] The static ring 4 is sealingly and slidingly installed on the shell 3. Specifically, an annular groove is formed on the outer circumferential side of the static ring 4, and an O-ring is arranged in the annular groove to achieve the sealing effect. The dynamic ring 1 is coaxial with the static ring 4, and the main shaft 2 penetrates the static ring 4. A gap is left between the inner side of the static ring 4 and the main shaft 2. Specifically, the diameter of the static ring 4 is greater than the diameter of the dynamic ring 1. When the main shaft 2 vibrates and deviates during high-speed rotation, the main shaft 2 will not come into contact with the inner circumferential side of the static ring 4.

[0040] The sealing end cover 5 can be installed on the shell 3 by bolts. Specifically, a hole is coaxially formed on the sealing end cover 5, and a sealing bearing is arranged in the hole. One end of the main shaft 2 penetrates the sealing bearing of the sealing end cover 5. The sealing bearing and the sealing end cover 5 can be installed by a rubber ring, so that when the main shaft 2 vibrates and deviates, the sealing bearing will also deviate synchronously. The sealing end cover 5 is installed with a contact spring 6 between the sealing end cover 5 and the static ring 4. The contact spring 6 provides elastic contact force in the axial direction of the static ring 4 and makes one end of the static ring 4 contact the contact surface of the dynamic ring 1. When the sealing end cover 5 is installed on the shell 3 by bolts, the contact spring 6 is in a semi-compressed state, and the static ring 4 is in contact with the contact surface of the dynamic ring 1. The contact spring 6 ensures that the static ring 4 can always contact the dynamic ring 1. In this way, when the main shaft 2 rotates, the dynamic ring 1 will also rotate on the static ring 4, effectively ensuring the sealing effect.

[0041] The oil circulation mechanism 7 is installed on the shell 3 and forms a lubricating oil path with the lubricating space to continuously provide lubricating oil to the lubricating space in a trickle form. That is, when the main shaft 2 of the nuclear main pump rotates, the dynamic ring 1 also rotates. At this time, the oil circulation mechanism 7 continuously outputs lubricating oil to the lubricating space in a small flow form. The lubricating oil in the lubricating space is located between the dynamic ring 1 and the static ring 4. When the main shaft 2 rotates with a small amplitude, the distribution of the lubricating oil is more uniform, thereby further improving the lubricating effect. By using the existing nuclear main pump, the main shaft 2 continuously rotates during operation, and the main shaft 2 rotates with a certain amplitude. The lubricating oil is effectively applied between the dynamic ring 1 and the static ring 4, the frictional resistance between the dynamic ring 1 and the static ring 4 is reduced, the use effect of the dynamic ring 1 and the static ring 4 is improved, the abrasion between the dynamic ring 1 and the static ring 4 is reduced, and the dynamic ring 1 and the static ring 4 are frequently replaced, thereby reducing the maintenance cost.

[0042] As shown in Figure 2 and Figure 6 In some embodiments, a convex ring 8 is arranged on the contact surface of the dynamic ring 1. A plurality of arc-shaped flanges 9 are arranged in the convex ring 8 and around the axis of the dynamic ring 1 in a circular array to form a lubricating space. Figure 6As shown, a gap is left between each arc-shaped convex plate 9, and the number of turns is not less than two turns. Adjacent two turns of arc-shaped convex plates 9 are staggered. The convex ring 8 is flush with the end face of the arc-shaped convex plate 9. The design of the convex ring 8 plays a main sealing role to prevent leakage. When the lubricating liquid enters the convex ring 8, the lubricating liquid will be thrown out between two arc-shaped convex plates 9 in the same turn due to the centrifugal force and then approach the inner edge of the convex ring 8 to quickly achieve the lubrication of the convex ring 8. The plurality of arc-shaped convex plates 9 also play a supporting role in auxiliary sealing to ensure that the static ring 4 is uniformly stressed. When the main shaft 2 has a small amplitude, because the dynamic ring 1 is still in a high-speed rotating state at this time, the small amplitude of the main shaft 2 can make the convex ring 8 and the arc-shaped convex plate 9 further complete the lubrication, thereby improving the lubrication effect.

[0043] As Figure 4 and Figure 11As shown, in some embodiments, the end face of the static ring 4 is provided with a circular array of two oil supply holes 10, and the end of the oil supply hole 10 away from the dynamic ring 1 is provided with a pipe 11 that is horizontally slidably inserted into the sealing end cover 5. The sealing end cover 5 is symmetrically provided with two circulating oil paths 12, and the two pipes 11 are respectively in communication with the two circulating oil paths 12. The circulating oil path 12 includes an L-shaped oil pipe embedded in the sealing end cover 5, and the outer circumferential side of the pipe 11 is fitted with the pre-provided hole of the sealing end cover 5 to serve as a guide. The inner circumferential side of the pipe 11 is slidably inserted into the horizontally oriented end of the oil pipe. When the sealing end cover 5 is installed and the static ring 4 is in contact with the dynamic ring 1, the pipe 11 is inserted into the oil pipe. Preferably, a sealing ring can be installed on the inner circumferential side of the pipe 11 to improve the sealing effect. Since the static ring 4 does not move horizontally during use, the sealing ring is not easily damaged, ensuring the sealing effect and preventing leakage of the lubricating liquid during flow. The oil circulation mechanism 7 is in communication with the two circulating oil paths 12. The oil circulation mechanism 7 causes the lubricating liquid to first enter the upper circulating oil path 12, then pass through the upper oil supply hole 10 into the convex ring 8, and then fill the convex ring 8 with lubricating liquid. Due to the action of gravity, the lubricating liquid flows into the lower circulating oil path 12, then passes through the lower oil supply hole 10, and finally enters the oil circulation mechanism 7 through the corresponding circulating oil path 12, completing the circulation of the lubricating liquid. It should be noted that the lower oil supply hole 10 is located in the convex ring 8, that is, when the convex ring 8 accumulates a certain height of lubricating liquid, the lubricating liquid in the convex ring 8 flows into the lower oil supply hole 10. When the multiple arc-shaped flanges 9 rotate, the ends of the arc-shaped flanges 9 carry the accumulated lubricating liquid upwards, thereby achieving continuous lubrication. Preferably, the two ends of the arc-shaped flange 9 can have a certain concave shape to carry more lubricating liquid, effectively preventing the static ring 4 from drying out and achieving continuous lubrication. Specifically, the end face of the outer shell 3 is provided with a gap, and the sealing end cover 5 is provided with two positioning blocks that match the gap to serve as an auxiliary positioning function. The outer circumferential side of the sealing end cover 5 is provided with a positioning hole, and the outer shell 3 is provided with a threaded hole. A headless bolt is used to position the sealing end cover 5, effectively preventing excessive friction between the static ring 4 and the dynamic ring 1 from causing excessive wear. A sealing ring can be installed on the contact part of the sealing end cover 5 and the end face of the outer shell 3 to further improve the sealing performance.

[0044] As Figure 4As shown, in some embodiments, the oil circulation mechanism 7 includes an oil box 701 disposed on the outer casing 3. The upper and lower ends of one side of the oil box 701 are connected to oil delivery pipes 702. The two oil delivery pipes 702 are respectively connected to two circulation oil circuits 12. After the sealing end cap 5 is installed, the oil delivery pipes 702 can be installed between the oil box 701 and the circulation oil circuit 12 by bolts. One of the oil delivery pipes 702 is equipped with a power component 14. The power component 14 can deliver the lubricating fluid in the oil box 701 to the corresponding oil delivery pipe 702. The power component 14 can deliver the lubricating fluid in the oil box 701 to the oil delivery pipe 702 located above. The upper part of the oil box 701 is connected to an oil supply pipe, which is used to fill the oil box 701 with lubricating fluid. The opening of the oil supply pipe can be screwed into a sealing bolt to prevent oil evaporation and the entry of dirt.

[0045] like Figure 8 As shown, in some embodiments, the power component 14 includes a mounting cylinder 1401 mounted on the housing 3. One end of the mounting cylinder 1401 is elastically slidably fitted with an actuating rod 1402. The free end of the actuating rod 1402 abuts against the outer periphery of the rotating ring 1. When the rotating ring 1 experiences a small amplitude vibration during rotation, the actuating rod 1402 moves vertically with a small amplitude. A conversion mechanism 15 connected to the oil supply pipe 702 is mounted on the mounting cylinder 1401. When the actuating rod 1402 moves, the conversion mechanism 15 converts the moving power of the actuating rod 1402 into oil transmission force. That is, at the height of the main shaft 2... When the rotating ring 1 vibrates slightly during high-speed rotation, the moving ring 1 will also vibrate accordingly. Since the actuating rod 1402 is against the outer circumference of the moving ring 1, the actuating rod 1402 will also move up and down slightly. As the actuating rod 1402 moves, the conversion mechanism 15 will convert the slight up and down movement of the actuating rod 1402 into the delivery of lubricating fluid. Thus, no additional driving force is needed to achieve the trickle flow of lubricating fluid. The lubricating fluid flows in the form of a trickle, which not only ensures the lubrication between the stationary ring 4 and the moving ring 1, but also effectively prevents the sealing effect from being affected by excessive oil pressure between the stationary ring 4 and the moving ring 1.

[0046] like Figure 8 and Figure 9As shown, in some embodiments, the conversion mechanism 15 includes a mounting box 1501 connected to the oil pipeline 702. A transmission gear 1502 is rotatably mounted inside the mounting box 1501. One of the transmission gears 1502 has its rotation shaft located externally and is fitted with a rotating cylinder 1503. A drive plate 1504 is rotatably mounted inside the mounting cylinder 1401. A wedge plate 1505 is vertically and elastically slidably mounted on the top of the drive plate 1504. Specifically, the drive plate 1504 has a mounting groove, and the wedge plate 1505 is slidably mounted in the mounting groove. The wedge plate 1505 and the mounting groove are installed... The rotating cylinder 1503 has a circular array of wedge-shaped grooves 1506 at its bottom for inserting wedge-shaped plates 1505. These grooves form an annular groove at the bottom of the rotating cylinder 1503. The drive plate 1504 and the actuating rod 1402 are linked and engaged. When the actuating rod 1402 reciprocates, the drive plate 1504 rotates reciprocally around its own axis. In other words, when the actuating rod 1402 reciprocates slightly, the drive plate 1504 also rotates reciprocally. However, when the drive plate 1504 rotates clockwise, the plane on one side of the wedge-shaped plate 1505 will engage with the wedge-shaped groove 1506. The planar contact of 506 causes one side of the wedge groove 1506 to move. When the drive plate 1504 reverses, the inclined surface of the wedge groove 1506 contacts the inclined surface of the wedge groove 1506, causing the wedge groove 1506 to retract into the mounting groove. This causes the rotating cylinder 1503 to rotate unidirectionally. It should be noted that the rotation of the two transmission gears 1502 and the rotating cylinder 1503 are in tight rotational engagement, which overcomes the elastic contact force of the wedge plate 1505 and prevents the wedge plate from contacting the inclined surface of the wedge groove 1506. When in contact, the rotating cylinder 1503 rotates, which in turn causes the transmission gear 1502 connected to it to rotate. Since the two transmission gears 1502 mesh with each other, when one transmission gear 1502 rotates, it will drive the other transmission gear 1502 to rotate. When the oil box 701 is full of oil, the oil supply pipe 702 located above will also be filled with lubricant. As the two transmission gears 1502 rotate, the gap between the two transmission gears 1502 will deliver the lubricant to the circulating oil circuit 12 located above, thereby achieving a trickle effect.

[0047] like Figure 10As shown, in some embodiments, an actuator 16 is vertically slidably mounted inside the mounting cylinder 1401. A conversion hole 17 is provided through the axis of the drive plate 1504. A spiral groove 18 is provided annularly on the inner circumference of the conversion hole 17. A guide plate 19 is constructed on the outer side of the actuator 16 and located within the spiral groove 18. That is, when the actuator 16 reciprocates, the movement of the actuator 16 will drive the guide plate 19 to move vertically. Because the guide plate 19 is located within the spiral groove 18, the vertical movement of the actuator 16 will drive the drive plate 1504. 04 reciprocates, thereby realizing the rotation of the drive plate 1504. The actuator 16 and the trigger rod 1402 are connected by non-contact transmission. When the trigger rod 1402 moves slightly, the actuator 16 moves significantly relative to the trigger rod 1402. In order to improve the rotation effect of the transmission gear 1502, when the trigger rod 1402 moves slightly, the actuator 16 will move synchronously and the movement range will be increased. The rotation range of the transmission gear 1502 will also be increased, thereby improving the effect of conveying lubricating fluid and improving the oil conveying efficiency.

[0048] like Figure 10 and Figure 11 As shown, in some embodiments, a retaining plate 20 is slidably mounted on the mounting cylinder 1401, and a retaining spring 21 is installed between the retaining plate 20 and the mounting cylinder 1401. One end of the retaining plate 20 abuts against one end of the actuating rod 1402. A connecting rod 22 is coaxially constructed on the retaining plate 20, and the connecting rod 22 is non-contactly connected to the actuating rod 16. In this embodiment, an annular groove is provided on the outer periphery of the actuating rod 1402, and a sealing ring is installed in the annular groove to prevent leakage. When the actuating rod 1402 moves vertically, it abuts against the retaining plate 20 and moves vertically. The diameter of the retaining plate 20 is larger than the diameter of the actuating rod 1402. The outer periphery of the retaining plate 20 fits against the inner periphery of the mounting cylinder 1401. A sealing ring can also be installed on the outer periphery of the retaining plate 20 for secondary sealing, which not only improves the sealing effect but also ensures the rotation of the transmission gear 1502.

[0049] like Figure 8 and Figure 10As shown, in some embodiments, the mounting cylinder 1401 has a small-diameter cavity 23 and a large-diameter cavity 24. The actuator 16 is slidably inserted into the small-diameter cavity 23. The end of the connecting rod 22 away from the actuating rod 1402 is equipped with a push plate 13 located in the large-diameter cavity 24. The large-diameter cavity 24 and the small-diameter cavity 23 are interconnected. A sealed area is formed between the push plate 13 and the actuator 16. When the actuating rod 1402 moves vertically back and forth, it will drive the connecting rod 22 to move vertically back and forth because of the push plate on the connecting rod 22. 13 is located inside the large-diameter cavity 24, so as the push plate 13 moves upward, the air inside the large-diameter cavity 24 will be squeezed into the small-diameter cavity 23. Because the diameter of the large-diameter cavity 24 is larger than the diameter of the small-diameter cavity 23, the vertical reciprocating amplitude of the actuator 16 located in the small-diameter cavity 23 will increase. The design of the retaining spring 21 is to help the push plate 13 to reset, ensuring that the trigger rod 1402 always abuts against the outer circumference of the moving ring 1. The rotating cylinder 1503 has a hole to ensure that the actuator 16 can move vertically.

[0050] like Figure 4 and Figure 5 As shown, in some embodiments, one end of the trigger rod 1402 is an outer arc surface, the oil box 701 is annular, and two filter plates 25 are installed inside the oil box 701. The two filter plates 25 divide the interior of the oil box 701 into upper and lower areas. When the oil in the oil box 701 circulates, fine metal shavings are generated due to the long-term friction between the convex ring 8 and the arc-shaped convex plate 9 and the stationary ring 4. As the metal shavings accumulate over time, the filter plates 25 in the oil box 701 can effectively prevent the oil from entering between the convex ring 8 and the stationary ring 4. When the stationary ring 4 and the stationary ring 1 rub against each other to form metal shavings, the flowing lubricant will carry some of the metal shavings. Finally, the filter plates 25 filter the impurities to prevent them from entering between the stationary ring 4 and the stationary ring 1 again, further reducing the friction between the stationary ring 4 and the stationary ring 1 and improving the efficiency of the stationary ring 4 and the stationary ring 1.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A mechanical seal structure of a nuclear primary pump comprising a main shaft (2) and a casing (3), characterized in that, Also include: The dynamic ring (1) is sleeved on the main shaft (2) and rotates synchronously with the main shaft (2), and a gap is left between the side of the dynamic ring (1) and the shell (3), one end of the dynamic ring (1) is a contact surface, and a lubrication space is arranged on the contact surface; The static ring (4) is sealingly and slidingly installed on the shell (3), the dynamic ring (1) is coaxial with the static ring (4) and the main shaft (2) passes through the static ring (4), and a gap is left between the inner side of the static ring (4) and the main shaft (2); The sealing end cover (5) is installed on the shell (3), one end of the main shaft (2) passes through the sealing end cover (5), the contact spring (6) is installed between the sealing end cover (5) and the static ring (4), the contact spring (6) provides elastic contact force in the axis direction of the static ring (4), and one end of the static ring (4) is in contact with the contact surface of the dynamic ring (1); The oil circulating mechanism (7) is installed on the shell (3) and forms a lubricating oil path with the lubrication space to continuously provide lubricating oil to the lubrication space in a trickle form; Two oil delivery holes (10) are arranged in a circular array on the end face of the static ring (4), one end of the oil delivery hole (10) away from the dynamic ring (1) is provided with a pipe (11), the pipe (11) is horizontally slidingly inserted into the sealing end cover (5), two circulating oil paths (12) are symmetrically arranged on the sealing end cover (5), two pipes (11) are respectively communicated with two circulating oil paths (12), and the oil circulating mechanism (7) is communicated with two circulating oil paths (12); The oil circulating mechanism (7) comprises an oil box (701) arranged on the shell (3), and the oil box (701) is communicated with two oil delivery pipes (702) at the upper end and the lower end on one side, the two oil delivery pipes (702) are respectively communicated with two circulating oil paths (12), and one of the oil delivery pipes (702) is provided with a power member (14), and the power member (14) is used for delivering the lubricating oil in the oil box (701) to the corresponding oil delivery pipe (702); The power member (14) comprises an installation cylinder (1401) installed on the shell (3), one end of the installation cylinder (1401) is elastically slidingly inserted with a touch rod (1402), the free end of the touch rod (1402) is in contact with the outer circumferential side of the dynamic ring (1), when the dynamic ring (1) has a small amplitude in rotation, the touch rod (1402) moves vertically with a small amplitude, the installation cylinder (1401) is provided with a conversion mechanism (15) communicated with the oil delivery pipe (702), when the touch rod (1402) moves, the conversion mechanism (15) is used for converting the moving power of the touch rod (1402) into oil transmission force.

2. The mechanical seal structure of the nuclear primary pump according to claim 1, characterized by A convex ring (8) is arranged on the contact surface of the dynamic ring (1), a plurality of arc-shaped convex plates (9) are arranged in a circular array in the convex ring (8) and around the axis of the dynamic ring (1) to form the lubrication space, a gap is left between each arc-shaped convex plate (9), the number of turns is not less than two, and the adjacent two turns of arc-shaped convex plates (9) are staggered, and the convex ring (8) is flush with the end face of the arc-shaped convex plate (9).

3. The mechanical seal structure of the nuclear primary pump according to claim 1, characterized by The conversion mechanism (15) comprises a mounting box (1501) communicated with the oil delivery pipe (702), transmission gears (1502) are rotatably installed in the mounting box (1501), one of the transmission gears (1502) has an external rotating shaft and is provided with a rotating cylinder (1503), a driving plate (1504) is rotatably installed in the mounting cylinder (1401), a wedge-shaped plate (1505) is vertically and elastically slidably installed at the top end of the driving plate (1504), a plurality of wedge-shaped grooves (1506) are formed in the bottom of the rotating cylinder (1503) and are arranged in a circular array, the wedge-shaped grooves (1506) are used for inserting the wedge-shaped plate (1505), and the driving plate (1504) is connected with the touch rod (1402) in a linkage manner, so that the driving plate (1504) rotates around its own axis when the touch rod (1402) reciprocates.

4. The mechanical seal structure of the nuclear primary pump according to claim 3, characterized by The mounting cylinder (1401) is vertically slidably installed with an execution rod (16), a conversion hole (17) is formed in the axis of the driving plate (1504), a helical groove (18) is formed in the inner wall of the conversion hole (17), the execution rod (16) is provided with a guide plate (19) located in the helical groove (18), and the execution rod (16) is connected with the touch rod (1402) in a non-contact transmission mode, so that the execution rod (16) reciprocates when the touch rod (1402) reciprocates.

5. The mechanical seal structure of the nuclear primary pump according to claim 4, wherein The mounting cylinder (1401) is slidably installed with a pressing plate (20), the pressing plate (20) is installed with a pressing spring (21) between the mounting cylinder (1401), one end of the pressing plate (20) abuts against one end of the touch rod (1402), the pressing plate (20) is coaxially provided with a connecting rod (22), and the connecting rod (22) is connected with the execution rod (16) in a non-contact transmission mode.

6. The mechanical seal structure of the nuclear primary pump according to claim 5, wherein The mounting cylinder (1401) has a small-diameter cavity (23) and a large-diameter cavity (24), the execution rod (16) is slidably inserted into the small-diameter cavity (23), the connecting rod (22) is provided with a pushing plate (13) located in the large-diameter cavity (24) at the end away from the touch rod (1402), the large-diameter cavity (24) and the small-diameter cavity (23) are in communication, and a sealed area is formed between the pushing plate (13) and the execution rod (16).

7. The mechanical seal structure of the nuclear primary pump according to claim 1, wherein One end of the touch rod (1402) is an outer arc surface, the oil box (701) is annular, and two filter plates (25) are installed in the oil box (701), so that the oil box (701) is divided into two regions.

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