Mechanical seal for multi-stage slurry pump

Abstract

This invention discloses a multi-layer mechanical seal for a slurry pump, comprising a pump cover, a rotating shaft, a bushing, a connecting flange, a rotating ring sleeve, and a second stationary ring. An end cover flange is provided at the end of the pump cover. An impeller hub is fitted onto the end of the rotating shaft located inside the pump cover. The bushing is fixedly fitted onto the rotating shaft, with its end face fitting against the end face of the impeller hub. The connecting flange is fixedly installed on the end face of the end cover flange. A first spring is fixedly connected to the inner bottom of the connecting flange, and a push ring is fixedly connected to the movable end of the first spring. A first stationary ring is fixedly connected to the end of the push ring. The rotating ring sleeve is fixedly fitted onto the bushing. A first rotating ring is provided on the left side of the rotating ring sleeve, with its end face fitting against the end face of the first stationary ring. A second rotating ring is provided on the top of the rotating ring sleeve. The second stationary ring is located on the inner wall of the pump cover, with its end face fitting against the end face of the second rotating ring. By setting up a multi-layer mechanical seal structure, the mechanical seal performance of the slurry pump is further improved.

Description

Technical Field

[0001] This invention relates to the field of mechanical seal technology, and more specifically to the mechanical seal of a multi-stage slurry pump. Background Technology

[0002] Mechanical seals mainly consist of a shaft sleeve, a rotating ring, a stationary ring, a sealing ring, a spring, a thrust ring, a spring seat, and various screws. Due to their advantages such as good sealing performance, low leakage, low friction loss, and long service life, mechanical seals are widely used in slurry pumps in mining, metallurgy, power generation, and environmental protection operations. Existing mechanical seals in slurry pumps achieve sealing through a set of mechanical seal components. During long-term use, under the high pressure and turbulent flow of the fluid medium within the pump cavity, smaller media particles continuously accumulate at the friction surfaces of the rotating and stationary rings. Excessive accumulation of fluid media particles at the friction surfaces causes destructive wear on the rotating and stationary rings, leading to media leakage.

[0003] For example, Chinese patent CN217539091 U discloses a mechanical seal structure for a ceramic slurry pump, including a pump shaft, a bushing fitted around the pump shaft, and a spring cover, a push ring, a stationary ring, and a rotating ring mounted on the bushing; a flange is mounted around the push ring, and the flange is connected to the spring cover via a support pipe; a first protrusion is provided on the circumference of the push ring, and the first protrusion engages with a first groove on the inner wall of the flange; a second protrusion is provided at one end of the push ring, and the second protrusion engages with a second groove on one side of the stationary ring; a transition ring is provided around the stationary ring, and a main stationary ring O-ring is provided between the transition ring and the stationary ring; a driving ring radial sealing ring is provided between the rotating ring and the bushing, and a third groove is provided on the inner wall of the rotating ring, which engages with a third protrusion fixed to the bushing; a pump cover is provided on one side of the flange, and a flange end face sealing ring is provided between the pump cover and the transition ring.

[0004] This mechanical seal structure not only has the above-mentioned problems, but also suffers from the following shortcomings: the huge heat generated by the friction between the dynamic ring and the stationary ring during operation cannot be cooled in time and sufficiently; the lubricating oil at the dynamic ring and the stationary ring is not easy to replenish; the friction surfaces of the dynamic ring and the stationary ring are dry, which further accelerates the damage at the friction surfaces and shortens the service life of the mechanical seal. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-layer mechanical seal for slurry pumps. By setting a multi-layer mechanical seal structure, the mechanical seal performance of the slurry pump is further improved, and the dynamic and static rings are fully cooled and the lubricating oil at the friction surfaces of the dynamic and static rings is easily replenished, which greatly extends the service life of the mechanical seal and solves the problems mentioned in the background art.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A mechanical seal for a multi-stage slurry pump includes a pump cover and a rotating shaft. An end cover flange is provided at the connection port of the pump cover, and an impeller hub is fitted onto the end of the rotating shaft located inside the pump cover. The seal also includes:

[0008] A bushing is fixedly sleeved on the rotating shaft, with the end face of the bushing in contact with the end face of the impeller hub, and an annular sealing ring is provided between the end face of the bushing and the end face of the impeller hub.

[0009] A connecting flange is fixedly mounted on the end face of the end cover flange. A first spring is fixedly connected to the inner bottom side of the connecting flange. A push ring is fixedly connected to the movable end of the first spring. A first stationary ring is fixedly connected to the end of the push ring. An annular sealing ring is provided between the first stationary ring and the inner wall of the end cover flange.

[0010] A rotating ring sleeve is fixedly sleeved on the bushing. A first rotating ring is provided on the left side of the rotating ring sleeve, which is in contact with the end face of the first stationary ring. A second rotating ring is provided on the top of the rotating ring sleeve.

[0011] The second stationary ring is disposed on the inner side wall of the pump cover, and the end face of the second stationary ring is in contact with the end face of the second moving ring.

[0012] As a further aspect of the present invention: a through hole is also provided inside the end cover flange, the through hole connecting the top outer wall of the end cover flange to the bottom inner wall of the end cover flange.

[0013] As a further embodiment of the present invention: an annular groove is formed on the inner wall of the second stationary ring, the second moving ring is movably disposed in the annular groove, and the top wall of the second moving ring is in contact with the top wall of the annular groove.

[0014] As a further aspect of the present invention: an annular limiting groove is formed on each of the two opposite sidewalls within the annular groove, and a sealing element is provided in each of the annular limiting grooves.

[0015] As a further aspect of the present invention: the sealing element includes:

[0016] The second spring, and several second springs are evenly arranged in the annular limiting groove;

[0017] A sealing ring is provided at the movable end of the second spring. An annular sealing groove matching the sealing ring is opened on both sides of the second moving ring, and the end of the sealing ring is fitted into the annular sealing groove.

[0018] As a further aspect of the present invention: a skeleton oil seal is provided between the connecting flange and the bushing, and an oil seal cover is provided on the side of the skeleton oil seal, the oil seal cover being used to fix the skeleton oil seal.

[0019] As a further aspect of the present invention: an annular sealing ring is provided between the push ring and the inner wall of the end cover flange.

[0020] As a further aspect of the present invention: an annular sealing ring is provided between the moving ring sleeve and the shaft sleeve.

[0021] As a further aspect of the present invention: both the first moving ring and the first stationary ring are made of silicon carbide ceramic material.

[0022] This invention has at least one of the following beneficial effects:

[0023] (1) By setting a mechanical seal structure of the first dynamic ring and the first stationary ring, another mechanical seal structure of the second dynamic ring and the second stationary ring, and the seal on the second stationary ring, the multi-layer mechanical seal can be compensated by another sealing component when one sealing component is damaged, thereby ensuring that the slurry pump will not leak the medium in the high pressure operating environment and greatly improving the mechanical seal performance of the slurry pump.

[0024] (2) The end cover flange, pump cover and multi-layer mechanical seal structure form a closed space. When the slurry pump is working, high-pressure cooling water can be injected into the closed space through the through hole. The cooling water can not only cool the mechanical seal structure in time, but also flush away small media particles attached to the friction surface of the mechanical seal, preventing small media particles from causing destructive wear of the dynamic ring and static ring.

[0025] (3) Lubricating oil can be injected into the enclosed space quickly and conveniently through the through hole at regular intervals, so as to avoid dry friction between the dynamic ring and static ring friction surfaces of the mechanical seal structure, which would further accelerate the damage at the friction surfaces and shorten the service life of the mechanical seal. Attached Figure Description

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is another overall structural schematic diagram of the present invention;

[0029] Figure 3 This is a schematic diagram of the moving ring sleeve structure of the present invention;

[0030] Figure 4 This is the present invention. Figure 1 Enlarged schematic diagram of the structure at point B;

[0031] Figure 5 This is the present invention. Figure 1 Enlarged schematic diagram of the structure at point A in the middle.

[0032] In the diagram: 1. Pump cover; 2. Shaft; 3. End cover flange; 4. Impeller hub; 5. Shaft sleeve; 6. Annular seal ring; 7. Connecting flange; 8. First spring; 9. Push ring; 10. First stationary ring; 11. Rotary ring sleeve; 12. First rotating ring; 13. Second rotating ring; 14. Second stationary ring; 15. Through hole; 16. Annular groove; 17. Annular limiting groove; 18. Seal; 19. Second spring; 20. Sealing ring; 21. Annular sealing groove; 22. Skeleton oil seal; 23. Oil seal gland; 24. Enclosed space. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "setting," and "sleeving" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Example 1

[0036] Please see Figure 1-5As shown, a mechanical seal for a multi-stage slurry pump includes a shaft sleeve 5, a connecting flange 7, a rotating ring sleeve 11, a first rotating ring 12, a first stationary ring 10, a second rotating ring 13, a second stationary ring 14, a first spring 8, a push ring 9, and an annular sealing ring 6. An end cover flange 3 is detachably and fixedly installed at the connection port of the pump cover 1 by bolts. Preferably, the end cover flange 3 is partially engaged with the side wall of the end cover connection port. An impeller hub 4 is detachably and fixedly sleeved on the end of the rotating shaft 2 located inside the pump cover 1. The shaft sleeve 5 is fixedly sleeved on the rotating shaft 2 of the slurry pump. The shaft sleeve 5 does not... The shaft sleeve 5 contacts the inner wall of the pump cover 1 and the end cover flange 3. The end face of the shaft sleeve 5 fits against the end face of the impeller hub 4, allowing the shaft sleeve 5 to rotate synchronously with the rotating shaft 2. An annular sealing ring 6 is provided between the end face of the shaft sleeve 5 and the end face of the impeller hub 4. The annular sealing ring 6 can be made of flexible materials such as rubber or silicone to improve the sealing performance between the shaft sleeve 5 and the end face of the impeller hub 4. The connecting flange 7 is fixedly connected to the end face of the end cover flange 3 by bolts. Preferably, the bottom part of the connecting flange 7 is engaged with the inner wall of the end cover flange 3, and the bottom of the connecting flange 7 does not contact the shaft sleeve 5. The first spring 8 is fixedly connected to the inner side. Specifically, an annular mounting groove can be opened on the inner side of the bottom of the connecting flange 7. One end of the first spring 8 is fixedly installed in the annular mounting groove. A push ring 9 is fixedly connected to the movable end of the first spring 8. The end of the push ring 9 is fixedly connected to the first stationary ring 10. The outer walls of the push ring 9 and the first stationary ring 10 are both in contact with the inner wall of the end cover flange 3. An annular sealing ring 6 is provided between the first stationary ring 10 and the inner wall of the end cover flange 3 to enhance the sealing between the first stationary ring 10 and the inner wall of the end cover flange 3. The moving ring sleeve 11 is fixedly sleeved on the bushing 5. The rotating shaft 2, bushing 5 and The three fixed positions of the rotating ring sleeve 11 are integrated. The bushing 5 and the rotating ring sleeve 11 rotate synchronously with the bushing 5. The first rotating ring 12 is provided on the left side of the rotating ring sleeve 11. The first rotating ring 12 is in contact with the end face of the first stationary ring 10. The second rotating ring 13 is provided on the top of the rotating ring sleeve 11. The second stationary ring 14 is provided on the inner side wall of the pump cover 1, and the end face of the second stationary ring 14 is in contact with the end face of the second rotating ring 13. The first rotating ring 12 and the second rotating ring 13 rotate with the rotating ring sleeve 11. The first spring 8 presses the push ring 9, and the push ring 9 presses the first stationary ring 10, so that the end face of the first stationary ring 10 is tightly in contact with the end face of the first rotating ring 12. The end cover flange 3, the pump cover 1, the first stationary ring 10, the first rotating ring 12, the second stationary ring 14, the second rotating ring 13, and the rotating ring sleeve 11 together form a closed space 24 between the end cover and the bushing 5.

[0037] During the operation of the slurry pump, the shaft sleeve 5, the rotating ring sleeve 11, the first rotating ring 12, and the second rotating ring 13 rotate at high speed around the circumference of the rotating shaft 2. The first rotating ring 12 and the first stationary ring 10 remain in contact and slide relative to each other, while the second rotating ring 13 and the second stationary ring 14 remain in contact and slide relative to each other, thereby preventing the fluid medium from leaking to the outside. If the end faces of the first rotating ring 12 and the first stationary ring 10 are worn, they can be automatically compensated by the first spring 8.

[0038] Furthermore, a through hole 15 is provided inside the end cover flange 3. The through hole 15 connects from the top outer wall of the end cover flange 3 to the bottom inner wall of the end cover flange 3 and extends into the enclosed space 24. When the slurry pump is working, high-pressure cooling water can be injected into the enclosed space 24 through the through hole 15. The cooling water can not only cool the mechanical seal structure in time, but also flush away small media particles attached to the friction surface of the mechanical seal, preventing small media particles from causing destructive wear of the dynamic ring and stationary ring. Lubricating oil can also be injected into the enclosed space 24 quickly and conveniently through the through hole 15 at regular intervals to avoid dry friction on the friction surface of the dynamic ring and stationary ring of the mechanical seal structure, which would further accelerate the damage at the friction surface and shorten the service life of the mechanical seal.

[0039] Furthermore, a skeleton oil seal 22 is provided between the connecting flange 7 and the bushing 5. An oil seal cover 23 is provided on the side of the skeleton oil seal 22. The oil seal cover 23 is used to fix the skeleton oil seal 22 and to ensure that the skeleton oil seal 22 is fixed in place. It is fixed to the connecting flange 7 with hex bolts and positioning clips. The skeleton oil seal 22 plays a role in preventing the leakage of cooling water or lubricating oil during the operation of the slurry pump.

[0040] Furthermore, an annular sealing ring 6 is provided between the push ring 9 and the inner wall of the end cover flange 3 to increase the sealing performance between the push ring 9 and the end cover flange 3.

[0041] Furthermore, an annular sealing ring 6 is provided between the moving ring sleeve 11 and the shaft sleeve 5. Specifically, the end of the shaft sleeve 5 that is in contact with the impeller hub 4 can be set as a stepped type, with the side wall of the moving ring sleeve 11 in contact with the stepped side wall of the shaft sleeve 5, and the annular sealing ring 6 is set between the side wall of the moving ring sleeve 11 and the stepped side wall of the shaft sleeve 5 to enhance the sealing between the moving ring sleeve 11 and the shaft sleeve 5.

[0042] By setting annular sealing rings 6 in multiple locations, the sealing performance of the mechanical seal mechanism of the slurry pump can be effectively improved, further ensuring the normal operation of the slurry pump.

[0043] Furthermore, both the first moving ring 12 and the first stationary ring 10 are made of silicon carbide ceramic material, which can improve the sealing performance of the first moving ring 12 and the first stationary ring 10, prevent slurry from contacting and corroding the metal, extend the service life of the mechanical seal structure, and bring good economic benefits to users.

[0044] Example 2

[0045] Please see Figure 1-5As shown, based on Embodiment 1, in this embodiment, an annular groove 16 is formed on the inner wall of the second stationary ring 14, and the second moving ring 13 is movably disposed in the annular groove 16, with the top wall of the second moving ring 13 fitting against the top wall of the annular groove 16. An annular limiting groove 17 is formed on each of the two opposite side walls of the annular groove 16, and a sealing element 18 is respectively disposed in the annular limiting groove 17. The sealing element 18 specifically includes a second spring 19 and a sealing ring 20. Several second springs 19 are evenly disposed in the annular limiting groove 17. The sealing ring 20 is disposed at the moving end of the second spring 19, and an annular sealing groove 21 matching the sealing ring 20 is formed on both sides of the second moving ring 13. Under the action of multiple second springs 19, the end of the sealing ring 20 is always fitted into the annular sealing groove 21.

[0046] During the operation of the slurry pump, the rotating ring sleeve 11 rotates at high speed around the circumference of the rotating shaft 2, causing the second rotating ring 13 to rotate with the rotating ring sleeve 11. The second rotating ring 13 and the second stationary ring 14 remain in contact and slide relative to each other. The end of the sealing ring 20 is in contact with the annular sealing groove 21 and moves relative to each other, thereby preventing the fluid medium from leaking into the closed space 24. If the end of the sealing ring 20 and the end face of the annular sealing groove 21 are worn, the second spring 19 can push the sealing ring 20 to automatically compensate, so that the end of the sealing ring 20 is always in contact with the annular sealing groove 21, ensuring the sealing performance of this mechanical seal.

[0047] The key improvement of this invention is as follows:

[0048] Taking the mechanical seal of the multi-layer slurry pump in Embodiment 2 as an example: 1. By setting a specially structured rotating ring sleeve 11, the second rotating ring 13 at the top of the rotating ring sleeve 11 fits against the second stationary ring 14 on the inner sidewall of the pump cover 1, forming a first-layer mechanical seal structure. The ends of the sealing rings 20 on both sides of the second stationary ring 14 are always fitted into the annular sealing groove 21, enhancing the sealing performance of the first-layer mechanical seal structure. 2. By setting a first rotating ring 12 and a first stationary ring 10, the first rotating ring 12 and the first stationary ring 10 remain in contact and can slide relative to each other, forming a second-layer mechanical seal structure. The first rotating ring 12 and the first stationary ring 10 are made of silicon carbide ceramic material, which improves the sealing performance of the first rotating ring 12 and the first stationary ring 10, prevents slurry from contacting and corroding the metal, and extends the life of the mechanical seal structure. 1. Service life, resulting in good economic benefits for users; 2. The end cover flange 3, pump cover 1, first stationary ring 10, first rotating ring 12, second stationary ring 14, second rotating ring 13, and rotating ring sleeve 11 together form a closed space 24 between the end cover and the shaft sleeve 5. When the slurry pump is working, high-pressure cooling water can be injected into the closed space 24 through the through hole 15. The cooling water can not only cool the mechanical seal structure in time, but also flush away small media particles attached to the friction surface of the mechanical seal, preventing small media particles from causing destructive wear of the rotating and stationary rings. Lubricating oil can also be injected into the closed space 24 quickly and conveniently through the through hole 15 at regular intervals, avoiding dry friction of the friction surfaces of the rotating and stationary rings in the mechanical seal structure, which further accelerates the damage at the friction surfaces and shortens the service life of the mechanical seal.

[0049] The preferred embodiments of the present invention have been described in detail above and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A mechanical seal for a multi-stage slurry pump, comprising a pump cover (1) and a rotating shaft (2), wherein an end cover flange (3) is provided at the connection port of the pump cover (1), and an impeller hub (4) is fitted on the end of the rotating shaft (2) located inside the pump cover (1), characterized in that, Also includes: A bushing (5) is fixedly sleeved on the rotating shaft (2). The end face of the bushing (5) is in contact with the end face of the impeller hub (4), and an annular sealing ring (6) is provided between the end face of the bushing (5) and the end face of the impeller hub (4). A connecting flange (7) is fixedly mounted on the end face of the end cover flange (3). A first spring (8) is fixedly connected to the inner bottom of the connecting flange (7). A push ring (9) is fixedly connected to the movable end of the first spring (8). A first stationary ring (10) is fixedly connected to the end of the push ring (9). An annular sealing ring (6) is provided between the first stationary ring (10) and the inner wall of the end cover flange (3). A rotating ring sleeve (11) is fixedly sleeved on a bushing (5). A first rotating ring (12) is provided on the left side of the rotating ring sleeve (11). The first rotating ring (12) is in contact with the end face of the first stationary ring (10). A second rotating ring (13) is provided on the top of the rotating ring sleeve (11). The second stationary ring (14) is disposed on the inner side wall of the pump cover (1), and the second stationary ring (14) is in contact with the end face of the second moving ring (13); The end cover flange (3), pump cover (1), first stationary ring (10), first moving ring (12), second stationary ring (14), second moving ring (13) and moving ring sleeve (11) together form a closed space (24) between the end cover and the bushing (5); The end cover flange (3) is also provided with a through hole (15), which is connected from the top outer wall of the end cover flange (3) to the bottom inner wall of the end cover flange (3); The inner wall of the second stationary ring (14) is provided with an annular groove (16), and the second moving ring (13) is movably disposed in the annular groove (16), and the top wall of the second moving ring (13) is in contact with the top wall of the annular groove (16); An annular limiting groove (17) is opened on each of the two opposite side walls of the annular groove (16), and a sealing element (18) is provided in each of the annular limiting grooves (17); The seal (18) includes: Second spring (19), a plurality of second springs (19) are evenly arranged in annular limiting groove (17); A sealing ring (20) is provided at the movable end of the second spring (19). An annular sealing groove (21) matching the sealing ring (20) is opened on both sides of the second moving ring (13). The end of the sealing ring (20) is attached to the annular sealing groove (21).

2. The mechanical seal of the multi-level slurry pump according to claim 1, characterized in that, A skeleton oil seal (22) is provided between the connecting flange (7) and the bushing (5). An oil seal cover (23) is provided on the side of the skeleton oil seal (22). The oil seal cover (23) is used to fix the skeleton oil seal (22).

3. The mechanical seal of the multi-stage slurry pump according to claim 1, characterized in that, An annular sealing ring (6) is provided between the push ring (9) and the inner wall of the end cover flange (3).

4. The mechanical seal of the multi-level slurry pump according to claim 1, characterized in that, An annular sealing ring (6) is provided between the moving ring sleeve (11) and the bushing (5).

5. The mechanical seal of the multi-stage slurry pump according to any one of claims 1 to 4, characterized in that, Both the first moving ring (12) and the first stationary ring (10) are made of silicon carbide ceramic material.

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