Mechanical sealing device capable of resisting positive and negative pressure of pump

Abstract

The utility model discloses a mechanical sealing device capable of resisting positive and negative pressure of a pump. The mechanical sealing device comprises a pump shaft, an impeller dismounting ring, an impeller and a mechanical sealing device body. The mechanical sealing device is fixedly connected with the mechanical sealing box, a shaft sleeve is arranged in the mechanical sealing device, a movable ring seat sleeve is installed on the shaft sleeve, a movable ring, a static ring and a push ring are sequentially installed between the movable ring seat sleeve and the end cover, and a spring is arranged between the push ring and the end cover to enable the movable ring and the static ring to be tightly attached. The impeller side mechanical sealing end cover is provided with an isolation water jacket, and a water outlet gap is formed between the isolation water jacket and the shaft sleeve to dissipate heat and prevent a pump cavity medium from entering; an outer spiral sleeve is arranged between the shaft sleeve on the side of the impeller dismounting ring and the positioning sleeve, the outer spiral sleeve is connected with a locking sleeve through threads, the locking sleeve is matched with an annular groove in the shaft sleeve in an inserted mode through a first fixing bolt, and the self-locking function is achieved. The device is ingenious in structure, the movable ring and the static ring are tightly attached to prevent leakage under the action of the spring, the sealing stability is improved through the design of the isolation water jacket, heat is effectively taken away, a sealing piece is protected, the pressure of a pump cavity is balanced, and the whole device has high stability and reliability.

Description

TECHNICAL FIELD

[0001] The utility model belongs to mechanical seal device technical field, especially relate to a kind of mechanical seal device that can resist pump positive and negative pressure. BACKGROUND

[0002] In the application field of slurry pump, shaft seal is the key component to ensure that the medium inside the pump body does not leak. At present, mechanical seal is generally used as shaft seal in domestic and foreign slurry pumps, which is due to the significant advantages of mechanical seal, such as no leakage, low power consumption and strong adaptability, so that it can adapt to various working conditions. However, under certain conditions, such as the working environment of tunnel slurry pump, mechanical seal faces unique challenges.

[0003] During the tunnel slurry discharge process, due to the possibility of containing large particle impurities or fibrous substances in the slurry, it is easy to cause pipeline blockage. When the pipeline is blocked, negative pressure will be generated in the pump cavity, resulting in instantaneous reduction of the cavity pressure. At this time, the atmospheric pressure will produce extrusion effect on the mechanical seal, and after the pipeline is dredged, the cavity pressure will quickly recover, forming positive pressure. The frequent alternation of negative pressure and positive pressure will cause the displacement of mechanical seal before and after, resulting in the loosening of locking device. Once the locking device is loosened, the two sealing surfaces of the sealing ring of the mechanical seal will be opened instantly, so that the slurry can invade, thereby causing the leakage problem of mechanical seal.

[0004] The existing mechanical seal locking device mainly adopts the mode of holding the dynamic ring seat sleeve and shaft sleeve tightly by bolt force to fix the mechanical seal on the pump shaft (or shaft sleeve). However, in the face of the special working conditions of frequent changes of positive and negative pressure, this locking mode often cannot effectively resist the impact force brought by pressure change, so as to ensure the reliability and stability of mechanical seal.

[0005] Therefore, in view of the problem of easy leakage of mechanical seal under special working conditions such as tunnel slurry pump, it is urgent to develop a kind of mechanical seal device which can resist the change of positive and negative pressure, so as to improve the adaptability and reliability of mechanical seal, and ensure the normal operation of slurry pump under harsh working conditions. UTILITY MODEL CONTENTS

[0006] In view of the problems existing in the prior art, the utility model provides a kind of mechanical seal device that can resist pump positive and negative pressure.

[0007] The utility model discloses a kind of mechanical sealing devices that can resist pump positive and negative pressure, including pump shaft, pump shaft one end is installed with impeller dismounting ring, the other end of pump shaft is installed impeller, and positioning sleeve and mechanical sealing device are equipped between impeller and impeller dismounting ring;Mechanical sealing device includes the mechanical sealing end cover fixedly connected with machine seal box, and shaft sleeve is equipped between mechanical sealing end cover and pump shaft, dynamic ring seat cover is installed on the shaft sleeve, and dynamic ring seat cover and end cover are sequentially installed with dynamic ring, static ring, push ring between dynamic ring seat cover and end cover.The spring that makes dynamic ring and static ring closely adhere is equipped between push ring and end cover;

[0008] It is characterized in that: on the mechanical sealing end cover, an isolation water jacket is installed on the impeller side, and a water outlet gap is provided between the isolation water jacket and the shaft sleeve; on the impeller dismounting ring side, an outer spiral sleeve is installed between the shaft sleeve and the positioning sleeve, a locking sleeve is installed on the outer spiral sleeve, the outer spiral sleeve and the locking sleeve are connected by threads, the locking sleeve is sleeved on the shaft sleeve, an annular groove is provided on the shaft sleeve, and a first fixing bolt is provided on the locking sleeve in the radial direction and inserted into the annular groove.

[0009] Further, a sliding groove is provided on the outer wall of the shaft sleeve in the axial direction, a second fixing bolt is provided on the dynamic ring seat cover and inserted into the sliding groove.

[0010] Further, an annular limiting groove is provided on the dynamic ring seat cover in the circumferential direction inside the second fixing bolt, and a temporary limiting plate is installed in the annular limiting groove.

[0011] Further, an exhaust hole is provided in the lower part of the dynamic ring of the dynamic ring seat cover.

[0012] Further, a turning hole is provided on the locking sleeve in the circumferential direction.

[0013] The utility model has the advantages and technical effects: the mechanical sealing device provided by the utility model can resist pump positive and negative pressure, and the overall technical effect is remarkable. Through the ingenious structure design, the device realizes high stability and reliability of mechanical sealing. Specifically, the dynamic ring and the static ring in the device are closely attached under the continuous pressing force of the spring, effectively preventing leakage and ensuring sealing effect. At the same time, the design of the isolation water jacket not only takes away the heat generated by the friction of the dynamic and static rings, but also prevents the medium in the pump cavity from entering the working environment of the sealing ring, protects the sealing element from corrosion and wear, balances the pump cavity pressure, and further improves the stability of the sealing.

[0014] In addition, the cooperation of the outer spiral sleeve and the locking sleeve realizes the self-locking function of the mechanical seal, and the locking becomes tighter along with the rotation of the pump shaft, effectively preventing the mechanical seal from moving forward and backward due to the change of positive and negative pressure, and enhancing the stability of the seal.

[0015] In addition, the exhaust hole on the dynamic ring seat sleeve effectively exhausts the air between the dynamic ring and the static ring, eliminates air resistance, and improves the reliability and service life of the seal. The design of the turning hole on the locking sleeve allows the operator to conveniently use a tool or manually rotate the locking sleeve, greatly facilitating the installation, disassembly or adjustment process of the mechanical seal.

[0016] The dynamic ring seat sleeve is also provided with N third fixing bolts, which are locked on the shaft sleeve after the pump adjustment is completed, preventing the dynamic ring seat sleeve from moving axially with the shaft sleeve due to external force, so as to be tightly fixed, and further improving the reliability of the seal.

[0017] In summary, the mechanical seal of the utility model improves the sealing effect, stability and reliability of the mechanical seal through a series of innovative designs, prolongs the service life, and provides a strong guarantee for the normal operation of the pump. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the utility model.

[0019] Figure 2 is a partial structural schematic diagram of the third fixing bolt of the utility model.

[0020] 1, isolation water jacket; 2, end cover; 3, dynamic ring seat sleeve; 3-1, annular groove; 3-2, annular limiting groove; 3-3, exhaust hole; 4, dynamic ring; 5, static ring; 6, push ring; 7, spring; 8, limiting plate; 9, locking sleeve; 10, outer spiral sleeve; 11, first fixing bolt; 12, turning hole; 13, shaft sleeve; 13-1, sliding groove; 14, positioning sleeve; 15, impeller dismounting ring; 16, impeller; 17, pump shaft; 18, mechanical seal box; 19, second fixing bolt; 20, third fixing bolt. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the following will be further described in detail by combining with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.

[0022] Please refer to Figure 1 and Figure 2A mechanical seal device capable of resisting positive and negative pressure of a pump, comprising a pump shaft 17, a pump shaft end provided with an impeller dismounting ring 15, the other end of the pump shaft provided with an impeller 16, a positioning sleeve 14 and a mechanical seal device between the impeller and the impeller dismounting ring, the mechanical seal device comprising a mechanical seal end cover 2 fixedly connected with a mechanical seal box 18, a shaft sleeve 13 provided between the mechanical seal end cover and the pump shaft, a dynamic ring seat sleeve 3 mounted on the shaft sleeve, a dynamic ring 4, a static ring 5 and a push ring 6 mounted in sequence between the dynamic ring seat sleeve 3 and the end cover 2, a spring 7 provided between the push ring and the end cover 2 to make the dynamic ring and the static ring tightly adhere to each other, the basic structure of the mechanical seal device, the tight adhesion of the dynamic ring and the static ring ensures the sealing effect, the spring 7 provides continuous compression force, so that the dynamic ring and the static ring can always maintain close contact during the operation of the pump, effectively preventing leakage; an isolation water sleeve 1 is mounted on the mechanical seal end cover on the impeller side, and a water outlet gap is provided between the isolation water sleeve and the shaft sleeve; the design of the isolation water sleeve can form an isolation space, and the cooling water is discharged through the water outlet gap, which can not only take away the heat generated by the friction between the dynamic ring and the static ring, but also prevent the medium in the pump cavity from entering the working environment of the sealing ring, thereby protecting the sealing element from corrosion and wear, balancing the pressure in the pump cavity and improving the stability of the sealing. On the shaft sleeve on the impeller dismounting ring side, an outer spiral sleeve 10 is mounted between the positioning sleeve and the shaft sleeve, a locking sleeve 9 is mounted on the outer spiral sleeve, the outer spiral sleeve and the locking sleeve are connected through threads, the locking sleeve is sleeved on the shaft sleeve 13, an annular groove 3-1 is provided on the dynamic ring seat sleeve, a first fixing bolt 11 is provided on the locking sleeve in the radial direction corresponding to the annular groove; the first fixing bolt is inserted into the annular groove. The design of the outer spiral sleeve and the locking sleeve realizes the self-locking function of the mechanical seal. The locking sleeve is tightly locked on the shaft sleeve through the cooperation of the first fixing bolt and the annular groove, and with the rotation of the pump shaft, the thread action between the outer spiral sleeve and the locking sleeve makes the locking more tightly, effectively preventing the mechanical seal from moving forward and backward due to the change of positive and negative pressure, and improving the stability and reliability of the sealing.

[0023] An outer wall of the shaft sleeve 13 is provided with a sliding groove 13-1 in the axial direction, a second fixing bolt 19 is provided on the dynamic ring seat sleeve 3, and the second fixing bolt is inserted into the sliding groove. The design of the sliding groove and the second fixing bolt enables the dynamic ring seat sleeve to be slightly adjusted in the axial direction on the shaft sleeve, facilitating the installation and adjustment of the mechanical seal. At the same time, the second fixing bolt provides additional fixing force, ensuring the stability of the dynamic ring seat sleeve during the operation of the pump, and further improving the reliability of the sealing.

[0024] An annular limiting groove 3-2 is provided on the dynamic ring seat sleeve 3 in the circumferential direction inside the second fixing bolt, and a temporary limiting plate 8 is mounted in the annular limiting groove.

[0025] The rotating ring seat 3 has a vent hole 3-3 at the lower part of the rotating ring. During rotating ring installation, the vent hole 3-3 allows air that may be present between the rotating and stationary rings to escape, ensuring a tight fit and improving the sealing effect. During pump operation, if air resistance forms between the rotating and stationary rings, it may affect the sealing performance. The presence of the vent hole 3-3 helps eliminate this air resistance, maintaining the stability of the seal. The design of the vent hole 3-3 reduces seal failure caused by residual air, thereby improving the reliability and service life of the mechanical seal.

[0026] The locking sleeve 9 has a rotating hole 12 along its circumference. The design of the rotating hole 12 allows the operator to use tools or manually rotate the locking sleeve 9, which is very convenient when installing, disassembling or adjusting the mechanical seal.

[0027] The rotating ring seat 3 is also provided with N third fixing bolts 20. After the pump is adjusted, the third fixing bolts are locked on the shaft sleeve to prevent the rotating ring seat and the shaft sleeve from moving axially due to external force, so as to fix them tightly and further improve the reliability of the seal.

[0028] This utility model relates to the installation steps of a mechanical seal device that can withstand positive and negative pressure from a pump:

[0029] First, the preparation stage:

[0030] Apply a small amount of silicone oil or grease to the surface of the pump shaft and the O-ring of the sealing bushing to facilitate installation and reduce friction.

[0031] Second, install the components:

[0032] Referring to the mechanical seal installation diagram, insert the positioning sleeve, outer spiral sleeve 10 and locking sleeve 9 assembly, along with the associated O-ring, onto the pump shaft in sequence until the impeller disassembly ring 15.

[0033] Third, assemble the mechanical seal:

[0034] The cartridge mechanical seal is installed on the shaft sleeve 13, ensuring that the rotating ring 4, stationary ring 5, and push ring 6 are sequentially installed between the rotating ring seat 3 and the mechanical seal end cover 2. A spring 7 is provided between the push ring 6 and the end cover 2 to provide continuous clamping force to ensure a tight fit between the rotating and stationary rings.

[0035] Fourth, fix the mechanical seal end cap:

[0036] Tighten the mechanical seal end cap 2 and the mechanical seal box 18 with bolts to ensure the basic structure of the mechanical seal device is stable.

[0037] Adjust the position of the locking sleeve:

[0038] Loosen the locking sleeve 9 to the side of the impeller dismounting ring 15, and make sure that the first fixing bolt 11 is not tightened, and the bolt cap is exposed at least 5mm.

[0039] At the same time, loosen the second fixing bolt 19, and make sure that the bolt can slide freely in the shaft sleeve key groove.

[0040] At the same time, the third fixing bolt 20 should also not be tightened.

[0041] Fifth, install the impeller and the front pump guard:

[0042] Install the impeller 16 and make sure that it is axially fixed. Then continue to install the front pump guard and other parts.

[0043] Sixth, adjust the bearing assembly:

[0044] After the pump is adjusted, the rotor is evenly and smoothly rotated, and there is no part contact and friction in the pump. On this basis, the positioning work of the mechanical seal can be carried out.

[0045] Seventh, position the mechanical seal:

[0046] After ensuring that the bearing assembly is in the correct position, carry out the positioning work of the mechanical seal. Tighten the second fixing bolt 19, and then tighten the third fixing bolt 20. Before tightening, apply thread locking agent to the threads.

[0047] Eighth, lock the locking sleeve:

[0048] Tighten the locking sleeve 9 until the tail end of the mechanical seal is in contact. Use an internal hex wrench to insert the rotating hole 12 on the locking sleeve, and make it tightly fixed.

[0049] Ninth, tighten the first fixing bolt:

[0050] Tighten the first fixing bolt 11 on the locking sleeve 9 with an internal hex wrench. Before tightening, apply thread locking agent to the threads. Tighten them in turn, ensuring that the tightening torque is not less than 20 Nm, and use an alternating method to lock them.

[0051] Tenth, remove the limiting plate:

[0052] Remove the four limiting plates of the mechanical seal, and turn the limiting plate by 180°. Then tighten it with a screw. This facilitates the positioning and dismounting of the mechanical seal in the future.

[0053] Eleventh, check and install auxiliary systems:

[0054] Check whether the sealing assembly is rubbing during rotation. The feeling should be uniform and smooth.

[0055] Install the flushing, cooling and other auxiliary systems to ensure that the mechanical seal is well lubricated and cooled during operation.

[0056] Through the above steps, it can be ensured that the mechanical sealing device capable of resisting positive and negative pressure of the pump is correctly and stably installed, so as to ensure the sealing effect and operation reliability.

[0057] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A mechanical seal device capable of resisting positive and negative pressure of a pump, comprising a pump shaft, a pump shaft end provided with an impeller dismounting ring, the other end of the pump shaft provided with an impeller, a positioning sleeve and a mechanical seal device arranged between the impeller and the impeller dismounting ring; the mechanical seal device comprising a mechanical seal end cover fixedly connected with a mechanical seal box, a shaft sleeve arranged between the mechanical seal end cover and the pump shaft, a dynamic ring seat sleeve mounted on the shaft sleeve, a dynamic ring, a static ring and a push ring sequentially arranged between the dynamic ring seat sleeve and the end cover; a spring arranged between the push ring and the end cover to tightly adhere the dynamic ring and the static ring; characterized in that on the impeller side, an isolation water jacket is mounted on the mechanical seal end cover, and a water outlet gap is arranged between the isolation water jacket and the shaft sleeve; on the impeller dismounting ring side, an outer spiral sleeve is mounted between the shaft sleeve and the positioning sleeve, a locking sleeve is mounted on the outer spiral sleeve, the outer spiral sleeve and the locking sleeve are connected through threads, the locking sleeve is sleeved on the shaft sleeve, and an annular groove is arranged on the shaft sleeve; a first fixing bolt is arranged on the locking sleeve in a radial direction and inserted into the annular groove.

2. The mechanical seal device according to claim 1, wherein: A sliding groove is arranged on an outer wall of the shaft sleeve in an axial direction, a second fixing bolt is arranged on the dynamic ring seat sleeve and inserted into the sliding groove.

3. The mechanical seal device according to claim 2, wherein: An annular limiting groove is arranged on the dynamic ring seat sleeve in a circumferential direction on an inner side of the second fixing bolt, and a temporary limiting plate is mounted in the annular limiting groove.

4. The mechanical seal device according to claim 1, wherein: An exhaust hole is arranged on a lower part of the dynamic ring of the dynamic ring seat sleeve.

5. The mechanical seal device according to claim 1, wherein: A turning hole is arranged on the locking sleeve in a circumferential direction.

Images