A mechanical seal for a feed water pump

Abstract

The present invention discloses a mechanical seal for a feed water pump, comprising a stationary ring assembly, a dynamic ring assembly, a gland assembly, a pump shaft, and a locking assembly. The stationary ring assembly and the dynamic ring assembly contact the end faces of the stationary ring and the dynamic ring through the static ring to achieve a dynamic end-face seal. The dynamic ring assembly is mounted on the pump shaft. The dynamic ring assembly includes a shaft sleeve, which is mounted with a shaft sleeve sealing ring. The shaft sleeve sealing ring respectively abuts against the pump shaft and shaft sleeve to achieve a static seal and prevent leakage of the medium. The present invention can ensure reliable operation of the feed water pump, a safe and stable process, and a stable sealing effect.

Description

Technical Field

[0001] The present invention relates to a mechanical seal in the field of nuclear power equipment, in particular to a mechanical seal for a feed water pump. Background Art

[0002] In nuclear power plants, the make-up water system performs multiple critical functions, including supplying water to the units during normal operation, filling the primary and secondary circuits prior to unit startup, and supplying cooling water to both critical and non-critical users. Furthermore, the make-up water system must ensure a normal replenishment of the secondary circuit equivalent to 1% of the rated steam generator output, and an emergency replenishment of 4-5% of the rated steam generator output to the turbine deaerator. The make-up water system is equipped with two make-up water pumps, which are used to provide normal make-up water to the main condenser and flush the pipelines prior to startup. Therefore, make-up water pumps play a crucial role in nuclear power systems and are crucial for ensuring stable operation. If a make-up water pump fails due to a mechanical seal failure, unpredictable and severe consequences can result. Therefore, the sealing performance and service life of the mechanical seal of the make-up water pump are crucial to its safety and reliability. Therefore, ensuring the stability and reliability of the mechanical seal, as well as facilitating installation and minimizing damage during assembly, has become a key technical challenge. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the above-mentioned technology and provide a mechanical seal for a feed water pump.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is a mechanical seal for a feed water pump: it includes a static ring assembly, a dynamic ring assembly, a pressure cover assembly, a pump shaft, and a locking assembly. The static ring assembly and the dynamic ring assembly are in contact with the end faces of the static ring and the dynamic ring through the static ring to achieve the purpose of end face dynamic sealing; the dynamic ring assembly is installed on the pump shaft; the dynamic ring assembly includes a shaft sleeve, and a shaft sleeve sealing ring is installed on the shaft sleeve. The shaft sleeve sealing ring respectively presses against the pump shaft and the shaft sleeve to achieve static sealing and prevent the medium from leaking through here.

[0005] Furthermore, the dynamic ring assembly also includes a dynamic ring sealing ring, a dynamic ring, a clamping ring, and a transmission block; the small diameter end of the sleeve is processed with two support ears and a threaded structure, the two support ears are respectively inserted into the strip groove of the pump shaft, and the sleeve and the pump shaft are circumferentially fixed by the two support ears; the large diameter end of the sleeve is processed with a sealing ring groove, a clamping ring groove and a semicircular groove structure for mounting the transmission block; two symmetrical planes are processed on the side surface of the dynamic ring, the dynamic ring is mounted in the sleeve and the bottom surface contacts the sleeve; the transmission block is a semicircular structure, the transmission block is mounted in the semicircular groove of the sleeve and one side of its plane matches the plane on the dynamic ring, so that the dynamic ring and the sleeve are kept circumferentially fixed; the dynamic ring sealing ring is mounted in the sleeve sealing ring groove and its two ends respectively press against the dynamic ring and the sleeve to achieve static sealing and prevent medium leakage from there; the clamping ring is mounted in the sleeve clamping ring groove to keep the dynamic ring axially positioned, so as to prevent the dynamic ring from falling off during the assembly of the feed water pump mechanical seal.

[0006] Furthermore, the stationary ring assembly includes a stationary ring, a stationary ring seat, a stationary ring seat sealing ring, a stationary ring sealing ring, a clamping ring, and a transmission block; a sealing ring groove is processed at one end of the small diameter of the stationary ring seat, a sealing ring groove, a clamping ring groove and a semicircular groove structure for installing the transmission block are processed at one end of the large diameter of the stationary ring seat, the stationary ring seat is installed on the spring seat assembly and is inserted into the spring seat assembly through its small diameter end to cooperate with it; two symmetrical planes are processed on the side surface of the stationary ring, the stationary ring is installed in the stationary ring seat and its bottom surface contacts the stationary ring seat; the stationary ring sealing ring is installed in the sealing ring groove of the stationary ring seat and its two ends respectively press against the stationary ring and the stationary ring seat to achieve static sealing and prevent medium leakage from there; the clamping ring is installed in the clamping ring groove of the stationary ring seat to keep the stationary ring axially positioned, which can prevent the stationary ring from falling off during the assembly of the mechanical seal of the feed water pump; the stationary ring seat sealing ring is installed in the sealing ring groove at one end of the small diameter of the stationary ring seat, which can ensure that the stationary ring seat can move axially while playing a sealing role.

[0007] Furthermore, the gland assembly includes a gland, a spring, a threaded cylindrical pin, a bolt A, a positioning block, and a bolt C; a plurality of spring holes, threaded holes, and through holes are processed on the gland, and the gland is installed on the water supply pump through the bolt C; the spring is installed in the spring hole on the gland, and the two ends of the spring respectively press against the gland and the static ring seat to provide the spring force required by the end face of the friction pair; the threaded cylindrical pin is installed on the gland and connected and fixed by a threaded manner, and the smooth end of the cylindrical threaded pin extends into the static ring seat, so that the static ring seat and the gland remain circumferentially fixed; the positioning block is installed on the gland by the bolt A, and the end of the positioning block away from the bolt A is inserted into the groove of the sleeve, and the sleeve and the gland maintain axial positioning to realize the containerized function.

[0008] Furthermore, the locking assembly includes a locking ring A, a locking ring B, a locking washer, and a bolt B; the locking ring A is installed on the threaded portion of the end of the sleeve through a threaded connection; the locking ring B is installed on the threaded portion of the pump shaft through a threaded connection; the bolt B is connected to the threaded hole of the locking ring A through the hole of the locking ring B, and finally the pump shaft and the sleeve can be fixed; the locking washer is installed under the bolt B to prevent the bolt B from loosening.

[0009] The advantages of the present invention over the prior art are that the present invention can achieve reliable operation of the feed water pump, a safe and stable process, and a stable sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of a mechanical seal for a feed water pump of the present invention.

[0011] Figure 2 It is a structural schematic diagram of a shaft sleeve of a mechanical seal for a feed water pump according to the present invention.

[0012] Figure 3 It is a structural schematic diagram of a dynamic ring of a mechanical seal for a feed water pump according to the present invention.

[0013] Figure 4 It is a structural schematic diagram of a transmission block of a mechanical seal for a feed water pump according to the present invention.

[0014] As shown in the figure: 1. Shaft sleeve, 2. Dynamic ring, 3. Stationary ring, 4. Stationary ring seat, 5. Stationary ring seat seal, 6. Pressure cover, 7. Positioning block, 8. Bolt A, 9. Locking ring A, 10. Locking ring B, 11. Locking washer, 12. Bolt B, 13. Threaded cylindrical pin, 14. Stationary ring seal, 15. Retaining ring, 16. Shaft sleeve seal, 17. Dynamic ring seal, 18. Bolt C, 19. Transmission block, 20. Spring, 21. Pump shaft. DETAILED DESCRIPTION

[0015] The following is a further detailed description of a mechanical seal for a feed water pump according to the present invention with reference to the accompanying drawings.

[0016] Combined with attachment Figure 1-4 A mechanical seal for a feed water pump includes a static ring assembly, a dynamic ring assembly, a pressure cover assembly, a pump shaft 21, and a locking assembly. The static ring assembly and the dynamic ring assembly are in contact with the end face of the dynamic ring 2 through the static ring 3 to achieve the purpose of end face dynamic sealing; the dynamic ring assembly is installed on the pump shaft 21; the dynamic ring assembly includes a shaft sleeve 1, and a shaft sleeve sealing ring 16 is installed on the shaft sleeve 1. The shaft sleeve sealing ring 16 respectively presses against the pump shaft 21 and the shaft sleeve 1 to achieve static sealing and prevent the medium from leaking through here.

[0017] The dynamic ring assembly also includes a dynamic ring seal 17, a dynamic ring 2, a retaining ring 15, and a transmission block 19; the small diameter end of the sleeve 1 is processed with two ears and a threaded structure, and the two ears are respectively inserted into the strip grooves of the pump shaft 21, and the two ears are used to achieve circumferential fixation of the sleeve 1 and the pump shaft 21; the large diameter end of the sleeve 1 is processed with a sealing ring groove, a retaining ring groove and a semicircular groove structure for installing the transmission block 19; two symmetrical planes are processed on the side of the dynamic ring 2, and the dynamic ring 2 is installed in the sleeve 1 and the bottom surface is in contact with the sleeve 1. ; The transmission block 19 is a semicircular structure. The transmission block 19 is installed in the semicircular groove of the sleeve 1 and one side of its plane cooperates with the plane on the dynamic ring 2, so that the dynamic ring 2 and the sleeve 1 can be kept circumferentially fixed; the dynamic ring sealing ring 17 is installed in the sealing ring groove of the sleeve 1 and its two ends respectively press against the dynamic ring 2 and the sleeve 1 to achieve static sealing and prevent the medium from leaking from there; the clamping ring 15 is installed in the clamping ring groove of the sleeve 1 to keep the dynamic ring 2 axially positioned, which can prevent the mechanical seal of the feed water pump from being damaged by the falling off of the dynamic ring 2 during the assembly process.

[0018] The stationary ring assembly includes a stationary ring 3, a stationary ring seat 4, a stationary ring seat sealing ring 5, a stationary ring sealing ring 14, a retaining ring 15, and a transmission block 19; the small diameter end of the stationary ring seat 4 is processed with a sealing ring groove, the large diameter end of the stationary ring seat 4 is processed with a sealing ring groove, a retaining ring groove and a semicircular groove structure for installing the transmission block 19, the stationary ring seat 4 is installed on the spring seat assembly and inserted into the spring seat assembly through its small diameter end to cooperate with it; two symmetrical planes are processed on the side of the stationary ring 3, the stationary ring 3 is installed in the stationary ring seat 4 and its bottom surface is aligned with the stationary ring seat 4. The static ring seat 4 is in contact with the static ring seat; the static ring sealing ring 14 is installed in the sealing ring groove of the static ring seat 4 and the two ends respectively press against the static ring 3 and the static ring seat 4 to achieve static sealing and prevent the medium from leaking from there; the clamping ring 15 is installed in the clamping ring groove of the static ring seat 4 to keep the static ring 3 axially positioned, which can prevent the damage caused by the falling of the static ring 3 during the assembly of the mechanical seal of the feed water pump; the static ring seat sealing ring 5 is installed in the sealing ring groove at one end of the small diameter of the static ring seat 4, which can ensure that the static ring seat 4 can move axially while playing a sealing role.

[0019] The gland assembly includes a gland 6, a spring 20, a threaded cylindrical pin 13, a bolt A8, a positioning block 7, and a bolt C18; a plurality of spring holes, threaded holes, and through holes are processed on the gland 6, and the gland 6 is installed on the water supply pump by means of bolt C18; the spring 20 is installed in the spring hole on the gland 6, and the two ends of the spring 20 respectively press against the gland 6 and the static ring seat 4 to provide the spring force required by the end face of the friction pair; the threaded cylindrical pin 13 is installed on the gland 6 and is connected and fixed by means of threads, and the smooth end of the cylindrical threaded pin 13 extends into the static ring seat 4, so that the static ring seat 4 and the gland 6 remain circumferentially fixed; the positioning block 7 is installed on the gland 6 by means of bolt A8, and the end of the positioning block 7 away from the bolt A8 is inserted into the groove of the shaft sleeve 1, and the shaft sleeve 1 and the gland 6 maintain axial positioning to realize the containerized function.

[0020] The locking assembly includes a locking ring A9, a locking ring B10, a locking washer 11, and a bolt B12; the locking ring A9 is installed on the threaded portion of the end of the sleeve 1 through a threaded connection; the locking ring B10 is installed on the threaded portion of the pump shaft 21 through a threaded connection; the bolt B12 is connected to the threaded hole of the locking ring A9 through the hole of the locking ring B10, and finally the pump shaft 21 and the sleeve 1 can be fixed; the locking washer 11 is installed under the bolt B12 to prevent the bolt B12 from loosening.

[0021] The present invention works like this:

[0022] After the feed water pump mechanical seal is installed on the equipment, remove the positioning block 7 to enter the operating state. During operation, the shaft sleeve seal 16, the dynamic ring seal 17, the static ring seal 14, and the static ring seat seal 5 provide a static seal, preventing medium leakage from these areas. The dynamic ring assembly rotates simultaneously with the pump shaft 21, while the static ring 3 remains circumferentially fixed. The two rings achieve sealing through end-face contact under the action of a spring.

[0023] The present invention: 1. The lug-type support on the end face of the feed water pump mechanical seal shaft sleeve can transmit greater torque and possess higher strength than traditional pins or keys, thereby increasing the reliability of the mechanical seal. 2. A tapered structure is designed at one end of the smaller diameter of the stationary ring seat of the feed water pump mechanical seal. This structure prevents the stationary ring seat from getting stuck during operation, ensuring that the friction pair end faces always receive a stable spring force, resulting in excellent sealing performance. 3. The semi-circular design of the transmission block increases its contact area with the dynamic and static rings, enabling the transmission of high torque without damaging the friction pair.

[0024] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A mechanical seal for a feed water pump, comprising a stationary ring assembly, a dynamic ring assembly, a gland assembly, a pump shaft (21), and a locking assembly, characterized in that: The static ring assembly and the dynamic ring assembly are in contact with the end faces of the dynamic ring (2) through the static ring (3) to achieve the purpose of end face dynamic sealing; the dynamic ring assembly is installed on the pump shaft (21); the dynamic ring assembly includes a shaft sleeve (1), and a shaft sleeve sealing ring (16) is installed on the shaft sleeve (1), and the shaft sleeve sealing ring (16) respectively presses against the pump shaft (21) and the shaft sleeve (1) to achieve static sealing and prevent the medium from leaking therethrough; The dynamic ring assembly further comprises a dynamic ring seal (17), a dynamic ring (2), a retaining ring (15), and a transmission block (19); two lugs and a threaded structure are machined on the small diameter end of the shaft sleeve (1), and the two lugs are respectively inserted into the strip grooves of the pump shaft (21), and the shaft sleeve (1) and the pump shaft (21) are fixed circumferentially by means of the two lugs; a sealing ring groove, a retaining ring groove, and a semicircular groove structure for mounting the transmission block (19) are machined on the large diameter end of the shaft sleeve (1); two symmetrical planes are machined on the side surface of the dynamic ring (2), and the dynamic ring (2) is mounted in the shaft sleeve (1) and the bottom surface contacts the shaft sleeve (1). The transmission block (19) is a semicircular structure. The transmission block (19) is installed in the semicircular groove of the shaft sleeve (1) and one side of its plane matches the plane on the dynamic ring (2), so that the dynamic ring (2) and the shaft sleeve (1) can be kept circumferentially fixed; the dynamic ring sealing ring (17) is installed in the sealing ring groove of the shaft sleeve (1) and its two ends respectively abut the dynamic ring (2) and the shaft sleeve (1) to achieve static sealing and prevent the medium from leaking therefrom; the clamping ring (15) is installed in the clamping ring groove of the shaft sleeve (1) to keep the dynamic ring (2) axially positioned, so as to prevent the dynamic ring (2) from falling off during the assembly process of the mechanical seal of the feed water pump. The stationary ring assembly comprises a stationary ring (3), a stationary ring seat (4), a stationary ring seat sealing ring (5), a stationary ring sealing ring (14), a retaining ring (15), and a transmission block (19); a sealing ring groove is machined on the small diameter end of the stationary ring seat (4), a sealing ring groove, a retaining ring groove and a semicircular groove structure for mounting the transmission block (19) are machined on the large diameter end of the stationary ring seat (4), and the stationary ring seat (4) is mounted on the spring seat assembly and inserted into the spring seat assembly through its small diameter end to cooperate with it; two symmetrical planes are machined on the side surface of the stationary ring (3), and the stationary ring (3) is mounted in the stationary ring seat (4) and its bottom surface In contact with the stationary ring seat (4); the stationary ring sealing ring (14) is installed in the sealing ring groove of the stationary ring seat (4) and the two ends respectively abut the stationary ring (3) and the stationary ring seat (4) to achieve static sealing and prevent the medium from leaking from there; the clamping ring (15) is installed in the clamping ring groove of the stationary ring seat (4) to keep the stationary ring (3) axially positioned, thereby preventing the damage caused by the stationary ring (3) falling off during the assembly process of the mechanical seal of the feed water pump; the stationary ring seat sealing ring (5) is installed in the sealing ring groove at one end of the small diameter of the stationary ring seat (4), and while playing a sealing role, it can also ensure that the stationary ring seat (4) can move axially; The gland assembly comprises a gland (6), a spring (20), a threaded cylindrical pin (13), a bolt A (8), a positioning block (7), and a bolt C (18); a plurality of spring holes, threaded holes, and through holes are processed on the gland (6); the gland (6) is mounted on the water supply pump via the bolt C (18); the spring (20) is mounted in the spring hole on the gland (6), and the two ends of the spring (20) respectively press against the gland (6) and the stationary ring seat (4), providing the spring force required by the end face of the friction pair; The threaded cylindrical pin (13) is mounted on the gland (6) and is connected and fixed by means of a thread. The smooth end of the threaded cylindrical pin (13) extends into the stationary ring seat (4), so that the stationary ring seat (4) and the gland (6) are kept circumferentially fixed. The positioning block (7) is mounted on the gland (6) by means of a bolt A (8). The end of the positioning block (7) away from the bolt A (8) is inserted into the groove of the shaft sleeve (1). The shaft sleeve (1) and the gland (6) are kept axially positioned, thereby realizing a containerized function. The locking assembly comprises a locking ring A (9), a locking ring B (10), a locking washer (11), and a bolt B (12); the locking ring A (9) is mounted on the threaded portion of the end of the sleeve (1) in the form of a threaded connection; the locking ring B (10) is mounted on the threaded portion of the pump shaft (21) in the form of a threaded connection; the bolt B (12) is connected to the threaded hole of the locking ring A (9) through the hole of the locking ring B (10), thereby finally achieving the fixation of the pump shaft (21) and the sleeve (1); the locking washer (11) is mounted under the bolt B (12) to prevent the bolt B (12) from loosening.

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