Shaft seal structure of slurry pump

Abstract

The utility model relates to the technical field of sealing of pump machines, in particular to a shaft seal structure of a slurry pump, which comprises a gland sealing ring, a gland, a shaft sleeve sleeved on a pump shaft and a sealing component positioned between the gland and the shaft sleeve, the gland sealing ring is sleeved on the shaft sleeve, and the end face of the gland sealing ring is abutted against the gland. A throttling sleeve is fixedly arranged on the end face, facing the medium side, of the gland and arranged on the periphery of the shaft sleeve in a sleeving mode, and an annular throttling gap is formed between the throttling sleeve and the shaft sleeve. The sealing assembly comprises a plurality of J-shaped sealing rings which are sequentially arranged in the axial direction of the shaft sleeve, and a spacer ring is arranged between every two adjacent J-shaped sealing rings. The service life of the shaft seal is prolonged to the maximum extent by improving the lubricity between the J-shaped sealing rings and adjusting coating materials and structures of the sealing rings and the shaft sleeve.

Description

TECHNICAL FIELD

[0001] The utility model belongs to pump machine sealing technical field, concretely relates to a shaft seal structure of slurry pump. BACKGROUND

[0002] Slurry pump is the key equipment in petroleum chemical industry, fine chemical industry, polymer production and many other industrial fields, and is widely used in conveying high viscosity, high solid concentration and medium that is easy to polymerize. The medium has obvious characteristics, such as poor fluidity or hard particles, or easy to self-polymerize under shear and temperature rise, which puts forward extremely harsh requirements for the shaft seal system of the pump.

[0003] At present, the shaft seal solutions for such harsh working conditions in the industry mainly fall into two categories: mechanical seal and packing seal (or its variants, such as J-type seal ring combination seal).

[0004] Mechanical seal, as a traditional sealing form, has the advantages of reliable sealing and low leakage rate. However, its inherent defects are greatly magnified when applied in such specific working conditions: 1. Customization is complex and costly: in order to adapt to high viscosity and easy polymerization medium, special customization design is necessary, including selection of special friction pair materials (such as hard alloy, engineering ceramics, etc.) resistant to wear and polymerization and design of high-performance flushing / blocking system matching them, which increases the initial purchase cost of the equipment. 2. High installation space and technical requirements: mechanical seal itself has complex structure and precise parts, requiring large axial and radial installation space. However, many slurry pumps pursue compact structure, and the shaft seal cavity space is usually extremely limited, which brings great difficulties to the installation and adjustment of mechanical seal. At the same time, professional tools and high-skilled technicians are needed for the installation process, and any deviation will affect the sealing effect. 3. High maintenance cost and unsatisfactory service life: even if high cost customization is carried out, the friction pair end face of the dynamic ring and static ring of the mechanical seal is still prone to abnormal wear, scratching and other conditions due to high viscosity and poor floatability of the medium. In addition, the easy polymerization medium may polymerize at the sealing end face, causing the sealing ring to be "stuck" and fail. As a result, the service life is much lower than expected, frequent shutdown replacement and maintenance not only generate high spare parts and labor costs, but also seriously affect the continuity and stability of the production process.

[0005] In order to overcome the above-mentioned shortcomings of mechanical seal, the industry turns to use J-type seal ring (or oil seal) combination seal form with simpler structure, which has the advantages of simple and compact structure, convenient installation, low requirement for installation space, relatively economical initial investment and maintenance cost. However, this solution also has its fatal shortcoming: short service life. Its failure mainly comes from:

[0006] 1. Lubrication and cooling deficiency: the lip of the J-shaped sealing ring and the surface of the shaft sleeve are in dry friction or boundary lubrication state, generating a large amount of friction heat at high speed. The original single-point flushing scheme cannot effectively and uniformly take away the friction heat and lubricate all the sealing lips, causing the lip material to accelerate aging, hardening and cracking due to high temperature, and easily wearing the shaft sleeve.

[0007] 2. Medium invasion and wear: lack of effective first barrier, hard particles in high-concentration slurry are easy to directly contact and abrade the lip of the J-shaped sealing ring, causing its sealing capacity to rapidly decrease.

[0008] 3. Shaft sleeve wear: the surface of the shaft sleeve in contact with the lip is insufficient in wear resistance, the traditional surface spray coating is thin and poor in bonding force, and is easy to peel off. Once the shaft sleeve is worn with grooves, even if the new sealing ring is replaced, the effective sealing cannot be restored.

[0009] Therefore, in view of the existing technical problems, it is also necessary to minimize the optimization and improvement of the existing slurry pump shaft seal structure, so as to improve its lubrication and cooling conditions, enhance its wear resistance, and block the direct invasion of the medium, so as to ensure the service life of the shaft seal structure of the slurry pump. Content of the utility model

[0010] The utility model aims at providing a shaft seal structure of a slurry pump, which can minimize the optimization and improvement of the existing slurry pump shaft seal structure, so as to improve its lubrication and cooling conditions, enhance its wear resistance, and block the direct invasion of the medium, so as to ensure the service life of the shaft seal structure of the slurry pump.

[0011] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0012] A shaft seal structure of a slurry pump, comprising a gland sealing ring, a gland, a shaft sleeve sleeved on a pump shaft, and a sealing assembly between the gland and the shaft sleeve, the gland sealing ring is sleeved on the shaft sleeve and its end face is abutted to the gland, a throttle sleeve is fixedly arranged on the end face of the gland towards the medium side, the throttle sleeve is sleeved on the outer periphery of the shaft sleeve, and an annular throttle gap is formed between the throttle sleeve and the shaft sleeve.

[0013] The sealing assembly comprises a plurality of J-shaped sealing rings arranged in sequence along the axial direction of the shaft sleeve, and a spacing ring is arranged between adjacent two J-shaped sealing rings.

[0014] Alternatively, the sealing assembly comprises a plurality of J-shaped sealing rings arranged in sequence along the axial direction of the shaft sleeve, and a spacing ring is arranged between adjacent two J-shaped sealing rings.

[0015] Alternatively, a plurality of through holes penetrating through both ends of the ring body are formed on the ring body of the spacing ring along the circumferential direction thereof.

[0016] Optionally, the number of the through holes is at least six, and the through holes are evenly distributed along the circumference of the spacer ring.

[0017] Optionally, two flushing liquid inlets and two flushing liquid outlets are arranged on the side wall of the gland.

[0018] One of the flushing liquid inlets is communicated with a cavity between the first J-shaped sealing ring and the second J-shaped sealing ring, and a corresponding one of the flushing liquid outlets is communicated with the cavity, forming a first flushing flow path.

[0019] Another one of the flushing liquid inlets is communicated with a cavity between the second J-shaped sealing ring and the other J-shaped sealing rings through the through hole on the spacer ring, and another corresponding one of the flushing liquid outlets is communicated with the cavity, forming a second flushing flow path.

[0020] Optionally, a wear-resistant coating is arranged on the surface of the shaft sleeve in contact with the lip of the J-shaped sealing ring, and the wear-resistant coating is a nickel-based alloy layer formed by a surfacing process.

[0021] Optionally, the thickness of the wear-resistant coating is 0.4-0.5mm.

[0022] Optionally, the two flushing liquid inlets are symmetrically arranged relative to the axis of the shaft sleeve, and / or the two flushing liquid outlets are symmetrically arranged relative to the axis of the shaft sleeve.

[0023] Optionally, the material of the J-shaped sealing ring closest to the medium side is polytetrafluoroethylene filled with molybdenum disulfide, and the materials of the other J-shaped sealing rings are graphite-filled polytetrafluoroethylene.

[0024] Optionally, the throttle sleeve is fixed to the gland by a second clamping ring.

[0025] Optionally, the shaft seal structure further comprises a positioning block, one end of the positioning block is fixedly connected with the gland, and the other end is connected with the shaft sleeve by clamping or pin connection, for limiting the relative axial movement between the gland and the shaft sleeve.

[0026] The positioning block is connected with the shaft sleeve by a transmission screw.

[0027] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0028] By the technical scheme, the throttle sleeve, as a non-contact physical barrier, can effectively prevent most of the high-concentration and high-viscosity slurry medium and hard particles contained therein from directly entering the main sealing area, reduces the risk of abrasive wear, chemical corrosion, and blockage and adhesion caused by medium polymerization borne by the rear main sealing assembly, and is beneficial to guarantee the service life of the entire shaft seal structure. Through pretreatment of the throttle sleeve, the working environment of the main sealing assembly is optimized, and direct operation of the main sealing assembly in extremely harsh conditions is avoided. This reduces unplanned downtime caused by sudden failure of the seal and ensures that the slurry pump can continuously and stably operate in a longer maintenance cycle. The throttle sleeve structure is ingeniously integrated in the end face of the gland, without occupying large axial or radial space, and is suitable for occasions where the shaft seal installation space of the slurry pump itself is limited. The throttle sleeve structure and the main sealing assembly form a two-stage sealing system, the first stage (throttle sleeve) is responsible for bearing the main pressure difference and blocking impurities, and the second stage (sealing assembly) is responsible for ensuring the final sealing, so that each stage can exert its maximum efficiency in a more suitable working condition through staged processing. BRIEF DESCRIPTION OF DRAWINGS

[0029] To more clearly illustrate the technical solutions of the example embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0030] Figure 1 The cross-sectional structure schematic diagram of the shaft seal structure of the slurry pump provided by the present application in an embodiment;

[0031] Figure 2 The partial structure schematic diagram of the shaft seal structure of the slurry pump provided by the present application in an embodiment;

[0032] Figure 3 The structure schematic diagram of the intermediate spacer ring in the shaft seal structure of the slurry pump provided by the present application;

[0033] Figure 4 The partial structure schematic diagram of the shaft seal structure of the slurry pump provided by the present application, in which the sealing cavity into which the chemical medium enters is colored and marked;

[0034] Figure 5 The partial structure schematic diagram of the shaft seal structure of the slurry pump provided by the present application, in which the lubricated sealing gap is colored and marked.

[0035] Marked in the drawing and corresponding part name: 1 - gland seal ring, 2 - gland, 3 - shaft sleeve, 4 - sealing assembly, 41 - J type seal ring, 42 - spacer ring, 51 - first seal ring, 52 - second seal ring, 6 - throttle sleeve, 7 - pressing plate, 8 - first clamping ring, 9 - shaft sleeve seal ring, 10 - positioning block, 101 - connecting screw, 102 - transmission screw, 110 - wear-resistant coating, 120 - second clamping ring, 130 - pump shaft. DETAILED DESCRIPTION

[0036] The utility model will be further described below in combination with the drawings and specific embodiments. It should be noted that the description of these embodiments is used to help understand the utility model and does not constitute a limitation on the utility model. The specific structure and functional details disclosed in this paper are only used to describe the embodiments of the utility model example. However, the utility model can be embodied in many alternative forms, and should not be understood as limiting the utility model in the embodiments described herein.

[0037] According to the specific embodiment of the present disclosure, a shaft seal structure of a slurry pump is provided. Wherein, Figures 1 to 5 A specific embodiment thereof is shown.

[0038] Referring to Figures 1 to 5 As shown, the shaft seal structure of the slurry pump comprises a gland seal ring 1, a gland 2, a shaft sleeve 3 sleeved on the pump shaft 130, and a sealing assembly 4 located between the gland 2 and the shaft sleeve 3. The gland seal ring 1 is sleeved on the shaft sleeve 3 and its end face is in close contact with the gland 2. Its characteristic is that the end face of the gland 2 towards the medium side is fixedly provided with a throttle sleeve 6, the throttle sleeve 6 is sleeved on the outer periphery of the shaft sleeve 3, and an annular throttling gap is formed between the throttle sleeve 6 and the shaft sleeve 3.

[0039] When the shaft seal structure of the slurry pump is working, the pump shaft 130 drives the shaft sleeve 3 to rotate synchronously. The high-pressure and high-viscosity slurry medium tends to leak outward along the surface of the shaft sleeve 3. The gland seal ring 1 fixed on the gland 2 fills the radial gap between the rotating shaft sleeve 3 and the stationary gland 2, effectively blocking the path of medium leakage along this radial direction. At the same time, the throttle sleeve 6 fixedly arranged on the end face of the gland 2 forms a narrow annular throttling gap between the rotating shaft sleeve 3, which constitutes a barrier to the axial flow of the medium. The throttle sleeve effectively prevents most of the chemical medium from entering the sealing cavity (such as Figure 4The color-filled block is the sealed cavity into which the chemical medium enters. When the medium flows through the throttling gap, it is subjected to great resistance due to the sudden contraction of the flow channel, and its pressure and flow rate are effectively attenuated. Most solid particles are blocked outside. The gland sealing ring 1 and the throttling sleeve 6 work together to form the first line of defense against radial and axial leakage paths, significantly reducing the medium pressure, erosion and pollution borne by the rear main sealing assembly 4. After the pressure is reduced by throttling, even if a small amount of medium penetrates, its pressure has been greatly reduced. The rear main sealing assembly 4 can thus operate in a more moderate and clean working condition, effectively completing the sealing task and achieving a longer service life due to the reduction of its load.

[0040] Through the above technical solution, the throttling sleeve 6 as a non-contact physical barrier can effectively block most high-concentration and high-viscosity slurry media and hard particles contained therein from directly entering the main sealing area, reducing the risk of abrasive wear, chemical corrosion, and blockage and adhesion caused by medium aggregation borne by the rear main sealing assembly 4, and benefiting the service life of the entire shaft seal structure. Through the pretreatment of the throttling sleeve 6, the working environment of the main sealing assembly 4 is optimized, avoiding its direct operation in extremely harsh conditions. This reduces unplanned downtime caused by sudden seal failure and ensures that the slurry pump can operate continuously and stably for a longer maintenance period. The throttling sleeve 6 is ingeniously integrated into the end surface of the gland 2 without occupying large axial or radial space, and is suitable for occasions where the shaft seal installation space of the slurry pump itself is limited. The throttling sleeve 6 structure cooperates with the main sealing assembly 4 to form a two-stage sealing system, the first stage (throttling sleeve 6) is responsible for bearing the main pressure difference and blocking impurities, and the second stage (sealing assembly 4) is responsible for ensuring the final sealing. Thus, through staged processing, each stage can perform its maximum efficiency in a more suitable working condition.

[0041] In the present disclosure, the shaft sleeve 3 is sealingly sleeved on the pump shaft 130 through the shaft sleeve 3 sealing ring, thereby ensuring the sealing.

[0042] It should be noted that the positional words such as "inner" and "outer" refer to the "inner" and "outer" relative to the profile of the component, and the direction towards the inside of the component is "inner", and vice versa. In addition, it should be noted that the terms such as "first" and "second" are used to distinguish one element from another, and do not have sequentiality and importance. Furthermore, in the following description, the same reference signs in different drawings represent the same elements. For the "and / or" appearing in the text, A and / or B means that there are three schemes: only A, only B, and A and B exist at the same time. And for the " / " appearing in the text, A / and B means that there are two schemes: only A exists, and A and B exist at the same time.

[0043] In one embodiment of this disclosure, the sealing assembly 4 includes a plurality of J-shaped sealing rings 41 arranged sequentially along the axial direction of the bushing 3, with a spacer ring 42 between adjacent J-shaped sealing rings 41. The plurality of J-shaped sealing rings 41 are arranged in series, forming three independent sealing barriers when mating with the bushing 3. This allows the pressure difference from the medium side to the atmosphere side to be progressively decomposed, with each sealing ring bearing a portion of the pressure load. This graded pressure reduction method alleviates the pressure difference burden on a single sealing ring, preventing its failure due to excessive local pressure. Even if the leading sealing ring experiences slight leakage under extreme conditions, subsequent sealing rings can still provide effective blocking, improving the sealing reliability of the sealing assembly 4 under pressure fluctuation conditions.

[0044] The spacer ring 42 set between adjacent sealing rings can axially separate several sealing rings, thereby forming two independent cavities (between the first and second rings, and between the second and third rings). This is beneficial for guiding the flushing fluid to flow, thereby efficiently removing the heat generated by friction in this area and lubricating the corresponding sealing ring lips, thus improving the problem of insufficient cooling and lubrication of some sealing rings in multi-seal systems.

[0045] In this disclosure, the sealing assembly 4 has a first end near the medium side and a second end near the atmosphere side. The first end of the sealing assembly 4 (specifically, the J-type sealing ring 41) is sealed to the gland 2 through the first sealing ring 51. The second end of the sealing assembly 4 (specifically, the J-type sealing ring 41) is provided with a pressure plate 7. The gland 2 is provided with a first retaining ring 8 that is disposed opposite to the pressure plate 7. The pressure plate 7 presses against the first retaining ring 8.

[0046] Specifically, see Figure 3 As shown, the spacer ring 42 has multiple through holes extending through both ends along its circumference. When the flushing fluid flows through, it can simultaneously and evenly flow from multiple points along the entire circumference to the surface of the rotating bushing 3, achieving all-round encapsulation lubrication of the lip contact area of ​​the J-type sealing ring 41. This effectively prevents problems such as hardening, cracking, and carbonization and polymerization of the sealing material caused by local overheating. In addition, the evenly distributed porous structure helps to establish a more balanced pressure field in the sealing cavities on both sides of the spacer ring 42 and reduces its dynamic interference to the lip of the J-type sealing ring 41, allowing the sealing lip to work in a more stable fluid environment. This helps to maintain a more stable sealing contact pressure, thereby improving the overall stability of the seal and reducing wear.

[0047] Further, the number of through holes is at least six and evenly distributed along the circumference of the spacer ring 42. By setting the number of through holes to at least six, the area for heat exchange and the distribution density of the cooling channels can be increased, so that the heat generated by friction can be quickly and uniformly dissipated through a larger area of liquid contact, preventing hardening, cracking of the sealing material due to local overheating, and polymerization of the medium at a local high temperature, and improving the thermal stability of the seal.

[0048] Evenly distributed along the circumference of the spacer ring 42, a smooth and uniform pressure distribution field can be formed, which is conducive to making the flushing liquid flow out at a substantially consistent flow rate and flow from all directions, thereby achieving stable fluid lubrication of the rotating shaft sleeve 3 surface, eliminating the possibility of local pressure unevenness or flow concentration due to too few through holes, and avoiding local abnormal wear of the J-shaped seal ring 41 lip due to uneven fluid impact.

[0049] In the present disclosure, eight through holes are evenly distributed along the circumference of the spacer ring 42, thereby ensuring more uniform lubrication of the flushing liquid in the sealing gap. As shown in Figure 5 The color-filled block is the lubricated sealing gap.

[0050] In one possible design, two flushing liquid inlets and two flushing liquid outlets are provided on the side wall of the gland 2; one flushing liquid inlet is in communication with the cavity between the first J-shaped seal ring 41 and the second J-shaped seal ring 41, and the corresponding flushing liquid outlet is in communication with the cavity, forming a first flushing flow path; the other flushing liquid inlet is in communication with the cavity between the second J-shaped seal ring 41 and the plurality of J-shaped seal rings 41 through the through holes on the spacer ring 42, and the corresponding other flushing liquid outlet is in communication with the cavity, forming a second flushing flow path.

[0051] The first flushing flow path can cool and lubricate the area between the first and second J-shaped seal rings 41. Since this area is closest to the medium side, the working temperature is higher and is easily affected by the medium. The second flushing flow path is used to cool and lubricate the area between the second and plurality of J-shaped seal rings 41, ensuring that both friction pairs of areas that are most prone to heat accumulation can be cooled sufficiently and efficiently, thereby reducing the actual working temperature of the lips of the J-shaped seal rings 41, delaying the aging, hardening and even failure speed of the sealing material, and further ensuring the use effect and service life.

[0052] Specifically, the two flushing liquid inlets are symmetrically arranged relative to the axis of the shaft sleeve 3. The flushing liquid is injected from two symmetric points, which can avoid uneven flow field in the cavity, vortex or dead zone caused by one-sided liquid injection, make the pressure distribution of the flushing liquid in the annular space around the shaft sleeve 3 more uniform, and make the flushing liquid uniformly cover and lubricate the lip contact area of the entire J-shaped sealing ring 41. Uniform flow field directly leads to uniform heat exchange, preventing local overheating of the shaft sleeve 3 or the sealing ring due to uneven circumferential cooling.

[0053] The two flushing liquid outlets are symmetrically arranged relative to the axis of the shaft sleeve 3, so that the heated flushing liquid and the trace wear particles or medium impurities carried out can be efficiently and smoothly discharged from the two symmetric points, avoiding the accumulation of impurities in some corners of the cavity or the formation of short circuit flow, so that the flushing liquid in all areas is in an efficient replacement state, maintaining the optimal cleanliness and cooling effect of the flushing liquid.

[0054] In a possible design, the material of the J-shaped sealing ring closest to the medium side is filled with molybdenum disulfide polytetrafluoroethylene, and the materials of the remaining J-shaped sealing rings are filled with graphite powder polytetrafluoroethylene.

[0055] Specifically, the material of the J-shaped sealing ring closest to the medium side is a polytetrafluoroethylene (PTFE) composite filled with molybdenum disulfide, and the materials of the remaining J-shaped sealing rings are graphite polytetrafluoroethylene. The J-shaped sealing ring closest to the medium side directly faces the slurry medium with high pressure, high viscosity and possibly containing hard particles, withstands fluid erosion, insufficient lubrication wear and chemical corrosion, and uses molybdenum disulfide reinforcing filler to greatly improve the relatively insufficient wear resistance of pure polytetrafluoroethylene material. The PV value of polytetrafluoroethylene is greatly improved, the high load, anti-compressive creep ability and excellent wear resistance enable it to more effectively resist the scraping and wear of the shaft sleeve and the sealing element by the high viscosity, prevent the hardening, creep or aggregation of the medium at the lip due to overheating, and thus ensure the service life of the J-shaped sealing ring (closest to the medium side) under harsh working conditions.

[0056] The working environment of the J-shaped sealing ring located at the rear has become relatively mild after the barrier effect of the first sealing ring and the lubrication and cooling of the flushing liquid, and mainly contacts the relatively clean flushing liquid or the trace medium with greatly reduced pressure. Selecting graphite powder filled polytetrafluoroethylene, this J-shaped sealing ring also improves the PV value, high load, wear resistance and other characteristics of polytetrafluoroethylene, but the cost is much lower than that of molybdenum disulfide filled polytetrafluoroethylene. Under the premise of improving lubrication and ensuring service life between the secondary and tertiary seals, reducing cost has great economic significance.

[0057] Based on the design of different materials for J-shaped sealing ring in different positions, the gradient defense structure is formed through the synergistic effect of front end wear-resistant heat conduction and rear end tight sealing, which improves the comprehensive performance and service life of the whole shaft seal structure in resisting high viscosity, high concentration and easily polymerized medium.

[0058] In an embodiment provided by the present disclosure, the surface of the shaft sleeve 3 in contact with the lip of the J-shaped sealing ring 41 is provided with a wear-resistant coating 110, which is a nickel-based alloy layer formed by a surfacing process. In this way, the shaft sleeve 3 can effectively resist the scraping of hard particles in high-concentration slurry and the continuous friction of the J-shaped sealing ring 41 lip, reducing the wear rate of the shaft sleeve 3 and avoiding sealing failure caused by wear marks and grooves on the surface of the shaft sleeve 3.

[0059] Further, the thickness of the wear-resistant coating 110 is 0.4-0.5mm, so that the surface geometry and microtopography of the contact area between the shaft sleeve 3 and the lip will remain highly stable, avoiding the problem of decreased followability of the sealing lip, loss of pre-tightening force and increased leakage rate caused by rapid wear of the surface of the shaft sleeve 3 and the appearance of grooves.

[0060] In an embodiment provided by the present disclosure, the throttle sleeve 6 is fixed to the gland 2 by the second collar 120. The collar is installed in the pre-set collar groove, which can provide stable and uniform radial restraint force, ensuring that the throttle sleeve 6 will not move axially or loosen when subjected to medium pressure fluctuations or shaft vibration, thereby ensuring the stability of the throttle gap and the persistence of the sealing barrier effect. The collar fixing structure is very flat and does not require additional axial arrangement space, which can better adapt to the application environment of the narrow space of the slurry pump shaft 130 sealing chamber. In this way, most of the chemical medium is effectively prevented from entering the sealing cavity by the throttle sleeve.

[0061] In an embodiment provided by the present disclosure, the shaft seal structure further comprises a positioning block 10, one end of which is fixedly connected with the gland 2, and the other end is connected with the shaft sleeve 3 by clamping or pinning, for limiting the relative axial movement between the gland 2 and the shaft sleeve 3. The positioning block 10 makes the gland 2 and the shaft sleeve 3 form a solid whole structure, avoiding the relative displacement of the shaft sleeve 3 and the gland 2 in the axial direction caused by vibration, thereby playing a certain protective role for the sealing element. During on-site installation, the operator only needs to directly fit the entire sealing assembly as a complete module on the pump shaft 130 and fasten it, which effectively simplifies the assembly process and significantly improves the installation efficiency and quality.

[0062] In the present disclosure, the positioning block 10 is fixedly connected to the gland 2 by the connecting screw 101, thereby facilitating installation and maintenance.

[0063] It should be noted that both the connecting screw 101 and the transmission screw 102 are screws in the prior art.

[0064] Further, the positioning block 10 is connected with the shaft sleeve 3 through the transmission screw 102. By tightening the transmission screw 102, the threads of the transmission screw 102 are tightly engaged with the screw hole on the shaft sleeve 3, so that the positioning block 10 is connected with the shaft sleeve 3 into an integrated body, avoiding displacement or loosening between the positioning block 10 and the shaft sleeve 3. During the assembly process, only the torque tool is needed to accurately control the fastening force, so that quick and reliable connection is realized, and the assembly efficiency and assembly quality are guaranteed. When maintenance is needed, the positioning block 10 can be separated from the shaft sleeve 3 by only disassembling the transmission screw 102, and then the sealing assembly is disassembled and replaced, greatly simplifying the maintenance process.

[0065] The above detailed description is used to further explain the purpose, technical scheme and beneficial effects of the utility model, and it should be understood that the above is only a specific embodiment of the utility model, and is not used to limit the protection scope of the utility model. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A shaft seal structure of a slurry pump, comprising a gland seal ring, a gland, a bushing which is fitted on a pump shaft, and a seal assembly which is located between the gland and the bushing, characterized in that, The gland sealing ring is sleeved on the shaft sleeve and abuts against the end face of the gland, and a throttle sleeve is fixedly arranged on the end face of the gland towards the medium side, the throttle sleeve is sleeved on the outer periphery of the shaft sleeve, and an annular throttle gap is formed between the throttle sleeve and the shaft sleeve; The sealing assembly comprises a plurality of J-shaped sealing rings arranged in sequence along the axial direction of the shaft sleeve, and a spacing ring is arranged between adjacent two J-shaped sealing rings.

2. The shaft seal structure of a slurry pump according to claim 1, characterized by, A plurality of through holes are formed in the annular body of the spacing ring along the circumferential direction of the annular body.

3. The shaft seal structure of a slurry pump according to claim 2, wherein The number of the through holes is at least six, and the through holes are uniformly distributed along the circumference of the spacing ring.

4. The shaft seal structure of a slurry pump according to claim 1, wherein Two flushing liquid inlets and two flushing liquid outlets are formed in the side wall of the gland. One of the flushing liquid inlets is in communication with a cavity between the first J-shaped sealing ring and the second J-shaped sealing ring, and the corresponding flushing liquid outlet is in communication with the cavity, forming a first flushing flow path. The other flushing liquid inlet is in communication with a cavity between the second J-shaped sealing ring and the plurality of J-shaped sealing rings through the through hole in the spacing ring, and the corresponding other flushing liquid outlet is in communication with the cavity, forming a second flushing flow path.

5. The shaft seal structure of a slurry pump according to claim 4, wherein The two flushing liquid inlets are symmetrically arranged relative to the axis of the shaft sleeve; and / or, the two flushing liquid outlets are symmetrically arranged relative to the axis of the shaft sleeve.

6. The shaft seal structure of a slurry pump according to claim 1, wherein The material of the J-shaped sealing ring closest to the medium side is polytetrafluoroethylene filled with molybdenum disulfide, and the materials of the remaining J-shaped sealing rings are polytetrafluoroethylene filled with carbon powder.

7. The shaft seal structure of a slurry pump according to claim 1, wherein The surface of the shaft sleeve in contact with the lip of the J-shaped sealing ring is provided with a wear-resistant coating, and the wear-resistant coating is a nickel-based alloy layer formed by a build-up welding process.

8. The shaft seal structure of a slurry pump according to claim 7, characterized by, The thickness of the wear-resistant coating is 0.4-0.5mm.

9. The shaft seal structure of a slurry pump according to claim 1, wherein The throttle sleeve is fixed to the gland by a second clamping ring.

10. The shaft seal structure of a slurry pump according to claim 1, wherein The shaft seal structure further comprises a positioning block, one end of the positioning block is fixedly connected with the gland, and the other end is clamped or pinned with the shaft sleeve, for limiting the relative axial movement between the gland and the shaft sleeve; the positioning block is connected with the shaft sleeve by a transmission screw.

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