Mechanical seal pump capable of preventing negative pressure evacuation

Abstract

The utility model relates to the technical field of sealing pumps, in particular to a mechanical sealing pump capable of preventing negative pressure evacuation, which comprises a pump body, a main shaft rotatably connected inside the pump body, an impeller mounted on the main shaft through a mounting nut, a pump cover mounted on the pump body, a shaft sleeve arranged between the pump cover and the main shaft, and an inner wall of the shaft sleeve fixedly connected with a peripheral wall of the main shaft. A limiting block is fixedly arranged in the pump cover, a mechanical seal inner static ring is arranged on the peripheral wall of the shaft sleeve in a sleeved mode, a mechanical seal fixing circular ring block is arranged between the limiting block and the mechanical seal inner static ring, a mechanical seal inner movable ring is arranged on the outer side wall of the mechanical seal inner static ring, a mechanical seal outer movable ring is arranged on the side, away from the impeller, of the mechanical seal inner movable ring, and the shaft sleeve is sleeved with the mechanical seal outer movable ring. And even under the negative pressure condition, the position of the static ring in the mechanical seal can be kept stable, the displacement or separation phenomenon is prevented, tight attachment of the sealing face is ensured, the sealing ring serves as an additional sealing barrier, and the sealing performance of the pump body is further enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of sealed pumps, in particular to a mechanical sealed pump for preventing negative pressure evacuation. Background Art

[0002] A mechanical sealed pump is a centrifugal pump equipped with a mechanical seal. To prevent the leakage of the medium transported by the pump, negative pressure evacuation usually occurs during the operation of the pump. Due to reasons such as a sudden drop in system pressure and the accumulation of gas in the pump, a negative pressure state appears in the pump, resulting in the pump being unable to work properly or the sealing performance deteriorating.

[0003] After retrieval, the Chinese patent with the publication number CN210068447U provides a pump body of a negative pressure pump and a chemical anti-corrosion negative pressure pump, including a housing. Diaphragm mounting holes are opened at both ends of the housing, and a motor connection hole is opened at the rear end of the housing. A cooling groove, a coolant outlet, and a coolant inlet are provided on the housing; the coolant outlet and the coolant inlet are respectively communicated with the cooling groove to maintain the temperature of the pump body during the operation of the negative pressure pump, thereby maintaining the working efficiency of the negative pressure pump. And due to the decrease in temperature, the service life of the negative pressure pump is improved.

[0004] However, it is found during use that when the inlet of the negative pressure pump is in a negative pressure state, due to the accumulation of gas in the pump and the instability of the system pressure, the stationary ring of the mechanical seal often shifts or separates, easily damaging the integrity of the mechanical seal, making the sealing surface unable to maintain a tight fit, thereby causing seal failure and fluid leakage, affecting the normal operation of the pump, resulting in shutdown, and even causing safety accidents. Summary of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the utility model provides a mechanical sealed pump for preventing negative pressure evacuation, which solves the technical problem that when the inlet of the negative pressure pump is in a negative pressure state, due to the accumulation of gas in the pump and the instability of the system pressure, the stationary ring of the mechanical seal often shifts or separates, easily damaging the integrity of the mechanical seal, making the sealing surface unable to maintain a tight fit, thereby causing seal failure and fluid leakage, affecting the normal operation of the pump, resulting in shutdown, and even causing safety accidents.

[0006] To solve the above technical problems, the utility model provides the following technical solution: A mechanical sealed pump for preventing negative pressure evacuation, including a pump body. A main shaft is rotatably connected inside the pump body. An impeller is installed on the main shaft through a mounting nut. A pump cover is installed on the pump body. A shaft sleeve is provided between the pump cover and the main shaft. The inner wall of the shaft sleeve is fixedly connected to the outer peripheral wall of the main shaft. A limiting block is fixedly provided inside the pump cover. A stationary ring inside the mechanical seal is sleeved on the outer peripheral wall of the shaft sleeve. A fixing circular ring block of the mechanical seal is provided between the limiting block and the stationary ring inside the mechanical seal.

[0007] Preferably, a dynamic seal ring inside the mechanical seal is provided on the outer side wall of the static seal ring inside the mechanical seal. An external dynamic seal ring of the mechanical seal is provided on the side of the dynamic seal ring inside the mechanical seal away from the impeller. The external dynamic seal ring of the mechanical seal is sleeved on the shaft sleeve, and the external dynamic seal ring of the mechanical seal is slidably connected to an external static seal ring of the mechanical seal.

[0008] Preferably, the outer peripheral walls of the static seal ring inside the mechanical seal and the external static seal ring of the mechanical seal are respectively fixedly connected to the pump cover, and the inner walls of the static seal ring inside the mechanical seal and the external static seal ring of the mechanical seal are respectively rotatably connected to the outer wall of the shaft sleeve.

[0009] Preferably, the inner walls of the dynamic seal ring inside the mechanical seal and the external dynamic seal ring of the mechanical seal are respectively fixedly connected to the shaft sleeve, and the outer peripheral walls of the dynamic seal ring inside the mechanical seal and the external dynamic seal ring of the mechanical seal are respectively rotatably connected to the inner wall of the pump cover.

[0010] Through the above technical solution, a certain flexibility is maintained between the dynamic seal ring and the static seal ring during the operation of the pump body to cope with the small displacements caused by the medium flow and temperature changes, and at the same time, the tight fit of the sealing surface is ensured.

[0011] Preferably, sealing rings are respectively installed between the limit block and the fixed circular ring block of the mechanical seal, between the dynamic seal ring inside the mechanical seal and the shaft sleeve, between the external dynamic seal ring of the mechanical seal and the shaft sleeve, and between the external static seal ring of the mechanical seal and the pump cover.

[0012] Through the above technical solution, as an additional sealing barrier, the sealing ring further enhances the sealing performance of the pump body.

[0013] Preferably, a limit groove is provided on the inner side wall of the side of the limit block close to the fixed circular ring block of the mechanical seal, and the outer side wall of the fixed circular ring block of the mechanical seal is in snap fit with the limit groove.

[0014] Through the above technical solution, the static seal ring inside the mechanical seal is further stabilized, preventing it from shifting or separating under negative pressure conditions.

[0015] Preferably, a protrusion is provided on the outer side wall of the static seal ring inside the mechanical seal, and the side of the fixed circular ring block of the mechanical seal close to the impeller abuts against the protrusion.

[0016] Through the above technical solution, the tight fit of the sealing surface is ensured, improving the overall stability and sealing performance of the mechanical seal system.

[0017] Advantages of the present utility model:

[0018] 1. When the medium in the pump body forms a negative pressure during operation due to reasons such as a decrease in system pressure or the accumulation of gas in the pump, the static seal ring inside the mechanical seal is firmly fixed between the pump cover and the shaft sleeve through the tight cooperation of the fixed circular ring block of the mechanical seal and the limit block, ensuring that even under negative pressure conditions, the static seal ring inside the mechanical seal can maintain its stable position and prevent the occurrence of displacement or separation phenomena.

[0019] 2. The dynamic ring inside the mechanical seal and the static ring inside the mechanical seal form the first seal, while the dynamic ring outside the mechanical seal and the static ring outside the mechanical seal form the second seal. The double-seal structure improves the sealing performance of the pump body. The dynamic ring inside the mechanical seal and the dynamic ring outside the mechanical seal are respectively fixedly connected to the shaft sleeve and can rotate on the inner wall of the pump cover. The static ring inside the mechanical seal and the static ring outside the mechanical seal are fixedly connected to the pump cover and rotatably connected to the outer wall of the shaft sleeve. There is a certain flexibility between the dynamic ring and the static ring during the operation of the pump body to cope with the small displacements caused by the medium flow and temperature changes, while ensuring the tight fit of the sealing surface. The sealing ring, as an additional sealing barrier, further enhances the sealing performance of the pump body.

[0020] 3. By increasing the snap-fit between the limit groove and the mechanical seal fixed circular ring block and strengthening the abutment design between the protrusion and the mechanical seal fixed circular ring block, the static ring inside the mechanical seal is further stabilized, preventing it from shifting or separating under negative pressure conditions. This double-stabilization mechanism ensures the tight fit of the sealing surface, improves the overall stability and sealing performance of the mechanical seal system, enables the pump body to operate more reliably under negative pressure conditions, effectively prevents fluid leakage problems caused by seal failure, and reduces energy loss and efficiency decline caused by seal problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the overall structure of the present utility model;

[0022] Figure 2 is an enlarged schematic diagram of the structure at A of the present utility model;

[0023] Figure 3 is an assembly schematic diagram of the structure of the mechanical seal fixed circular ring block of the present utility model;

[0024] Figure 4 is a schematic diagram of the structure of the static ring inside the mechanical seal of the present utility model.

[0025] In the figure: 1. Pump body; 2. Installation nut; 3. Impeller; 4. Pump cover; 5. Shaft sleeve; 6. Static ring inside the mechanical seal; 7. Mechanical seal fixed circular ring block; 8. Dynamic ring inside the mechanical seal; 9. Dynamic ring outside the mechanical seal; 10. Static ring outside the mechanical seal; 11. Protrusion; 12. Limit block; 13. Sealing ring; 14. Limit groove; 15. Main shaft. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to make the above objects, features, and advantages of the present utility model more obvious and understandable, the following detailed description of the specific embodiments of the present utility model is given in conjunction with the accompanying drawings of the specification. Embodiment 1

[0027] As Figures 1 to 4As shown in the figure, this embodiment provides a mechanical seal pump for preventing negative pressure evacuation, which includes a pump body 1. A main shaft 15 is rotatably connected inside the pump body 1. An impeller 3 is installed on the main shaft 15 through a mounting nut 2. A pump cover 4 is installed on the pump body 1. A shaft sleeve 5 is provided between the pump cover 4 and the main shaft 15. The inner wall of the shaft sleeve 5 is fixedly connected to the outer peripheral wall of the main shaft 15. A limiting block 12 is fixedly arranged inside the pump cover 4. A static ring 6 inside the mechanical seal is sleeved on the outer peripheral wall of the shaft sleeve 5. A fixing ring block 7 for the mechanical seal is arranged between the limiting block 12 and the static ring 6 inside the mechanical seal.

[0028] An inner dynamic ring 8 of the mechanical seal is arranged on the outer side wall of the static ring 6 inside the mechanical seal. An outer dynamic ring 9 of the mechanical seal is arranged on the side of the inner dynamic ring 8 of the mechanical seal away from the impeller 3. The outer dynamic ring 9 of the mechanical seal is sleeved on the shaft sleeve 5. The outer dynamic ring 9 of the mechanical seal is slidably connected to an outer static ring 10 of the mechanical seal. The outer peripheral walls of the static ring 6 inside the mechanical seal and the outer static ring 10 of the mechanical seal are respectively fixedly connected to the pump cover 4. The inner walls of the static ring 6 inside the mechanical seal and the outer static ring 10 of the mechanical seal are respectively rotatably connected to the outer wall of the shaft sleeve 5. The inner walls of the inner dynamic ring 8 of the mechanical seal and the outer dynamic ring 9 of the mechanical seal are respectively fixedly connected to the shaft sleeve 5. The outer peripheral walls of the inner dynamic ring 8 of the mechanical seal and the outer dynamic ring 9 of the mechanical seal are respectively rotatably connected to the inner wall of the pump cover 4; there is a certain flexibility between the dynamic ring and the static ring during the operation of the pump body 1 to cope with the small displacements caused by the medium flow and temperature changes, while ensuring the tight fit of the sealing surface.

[0029] Sealing rings 13 are respectively installed between the limiting block 12 and the fixing ring block 7 for the mechanical seal, between the inner dynamic ring 8 of the mechanical seal and the shaft sleeve 5, between the outer dynamic ring 9 of the mechanical seal and the shaft sleeve 5, and between the outer static ring 10 of the mechanical seal and the pump cover 4; the sealing rings 13, as additional sealing barriers, further enhance the sealing performance of the pump body 1.

[0030] Working principle: When the medium in the pump body 1 forms a negative pressure due to reasons such as a decrease in the system pressure or the accumulation of gas in the pump during operation, the static ring 6 inside the mechanical seal is firmly fixed between the pump cover 4 and the shaft sleeve 5 through the tight cooperation of the fixing ring block 7 for the mechanical seal and the limiting block 12, ensuring that even under negative pressure conditions, the static ring 6 inside the mechanical seal can maintain its stable position and prevent the occurrence of displacement or separation phenomena;

[0031] The inner dynamic ring 8 of the mechanical seal and the static ring 6 inside the mechanical seal form the first seal, while the outer dynamic ring 9 of the mechanical seal and the outer static ring 10 of the mechanical seal form the second seal. The double-seal structure improves the sealing performance of the pump body 1. The inner dynamic ring 8 of the mechanical seal and the outer dynamic ring 9 of the mechanical seal are respectively fixedly connected to the shaft sleeve 5 and can rotate on the inner wall of the pump cover 4, while the static ring 6 inside the mechanical seal and the outer static ring 10 of the mechanical seal are fixedly connected to the pump cover 4 and rotatably connected to the outer wall of the shaft sleeve 5. There is a certain flexibility between the dynamic ring and the static ring during the operation of the pump body 1 to cope with the small displacements caused by the medium flow and temperature changes, while ensuring the tight fit of the sealing surface. The sealing rings 13, as additional sealing barriers, further enhance the sealing performance of the pump body 1. Embodiment 2

[0032] As Figures 1 to 4 shown, on the basis of Embodiment 1, a limiting groove 14 is provided on the inner wall of one side of the limiting block 12 close to the mechanical seal fixing ring block 7, and the outer wall of the mechanical seal fixing ring block 7 is in clamping fit with the limiting groove 14; further stabilizing the static ring 6 inside the mechanical seal and preventing it from shifting or separating under negative pressure conditions.

[0033] A protrusion 11 is provided on the outer wall of the static ring 6 inside the mechanical seal, and one side of the mechanical seal fixing ring block 7 close to the impeller 3 abuts against the protrusion 11; ensuring the tight fit of the sealing surface and improving the overall stability and sealing performance of the mechanical seal system.

[0034] During use, by increasing the clamping fit between the limiting groove 14 and the mechanical seal fixing ring block 7 and strengthening the abutting design between the protrusion 11 and the mechanical seal fixing ring block 7, the static ring 6 inside the mechanical seal is further stabilized, preventing it from shifting or separating under negative pressure conditions. This dual stabilization mechanism ensures the tight fit of the sealing surface, improves the overall stability and sealing performance of the mechanical seal system, enables the pump body 1 to operate more reliably under negative pressure conditions, effectively prevents fluid leakage problems caused by seal failure, and reduces energy loss and efficiency decline caused by seal problems.

[0035] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A mechanical seal pump for preventing negative pressure evacuation, comprising a pump body (1), characterized in that: The pump body (1) is rotatably connected to a main shaft (15), the main shaft (15) is mounted with an impeller (3) via a mounting nut (2), a pump cover (4) is mounted on the pump body (1), a shaft sleeve (5) is provided between the pump cover (4) and the main shaft (15), and the inner wall of the shaft sleeve (5) is fixedly connected to the outer peripheral wall of the main shaft (15); A limit block (12) is fixedly arranged inside the pump cover (4), a mechanical seal internal static ring (6) is sleeved on the outer peripheral wall of the shaft sleeve (5), and a mechanical seal fixing annular block (7) is arranged between the limit block (12) and the mechanical seal internal static ring (6).

2. The mechanical seal pump for preventing negative pressure evacuation as claimed in claim 1, characterized in that: An inner mechanical seal moving ring (8) is provided on the outer side wall of the inner mechanical seal static ring (6), an outer mechanical seal moving ring (9) is provided on the side of the inner mechanical seal moving ring (8) away from the impeller (3), the outer mechanical seal moving ring (9) is sleeved on the shaft sleeve (5), and the outer mechanical seal moving ring (9) is slidably connected to the outer mechanical seal static ring (10).

3. The mechanical seal pump for preventing negative pressure evacuation as claimed in claim 2, characterized in that: The outer peripheral walls of the mechanical seal inner static ring (6) and the mechanical seal outer static ring (10) are respectively fixedly connected to the pump cover (4), and the inner walls of the mechanical seal inner static ring (6) and the mechanical seal outer static ring (10) are respectively rotatably connected to the outer wall of the shaft sleeve (5).

4. The mechanical seal pump for preventing negative pressure evacuation as claimed in claim 2, characterized in that: The inner walls of the mechanical seal inner dynamic ring (8) and the mechanical seal outer dynamic ring (9) are respectively fixedly connected to the shaft sleeve (5), and the outer peripheral walls of the mechanical seal inner dynamic ring (8) and the mechanical seal outer dynamic ring (9) are respectively rotatably connected to the inner wall of the pump cover (4).

5. The mechanical seal pump for preventing negative pressure evacuation as claimed in claim 4, characterized in that: Sealing rings (13) are respectively installed between the limit block (12) and the machine seal fixed annular block (7), between the internal dynamic ring (8) of the machine seal and the shaft sleeve (5), between the external dynamic ring (9) of the machine seal and the shaft sleeve (5), and between the external static ring (10) of the machine seal and the pump cover (4).

6. The mechanical seal pump for preventing negative pressure evacuation as claimed in claim 5, characterized in that: A limiting groove (14) is provided on an inner wall of one side of the limiting block (12) close to the machine seal fixing circular ring block (7), and an outer wall of the machine seal fixing circular ring block (7) is snap-fitted with the limiting groove (14).

7. The mechanical seal pump for preventing negative pressure evacuation as claimed in claim 2, characterized in that: A protrusion (11) is provided on the outer side wall of the static ring (6) inside the mechanical seal, and a side of the mechanical seal fixed annular block (7) close to the impeller (3) abuts against the protrusion (11).

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