Self-adaptive mechanical sealing structure for centrifugal pump

Abstract

The utility model provides a self-adaptive mechanical sealing structure for a centrifugal pump. According to the technical scheme, the self-adaptive mechanical sealing structure is characterized by comprising a rotating assembly driven by a pump shaft to rotate, a spring assembly and a static assembly static relative to the pump shaft; a pump shaft sleeve is fixedly arranged outside the pump shaft; the pump shaft sleeve is matched with the rotating assembly and the spring assembly; the rotating assembly comprises a movable ring and a transmission sleeve. The static assembly comprises a static ring and a static ring sleeve; the spring assembly comprises a spring, a corrugated pipe and a spring cover which abuts against and supports the spring. The movable ring is fixedly connected with the corrugated pipe through the transmission sleeve; a straining ring is arranged on the peripheral face of the corrugated pipe and elastically abuts against the inner wall of the transmission sleeve. The self-adaptive mechanical sealing structure for the centrifugal pump has the beneficial effects that transmission is efficient, mounting and dismounting are convenient, the mounting space is saved, through the shape design of the corrugated pipe pair, the contact pressure on the sealing face is stable, abrasion is uniform, and therefore the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical seal, in particular to a self-adaptive mechanical seal structure for centrifugal pump. BACKGROUND

[0002] The mechanical seal structure of centrifugal pump is the core component to ensure the efficient and safe operation of the equipment, mainly used for preventing medium leakage and maintaining the pressure stability in the sealing cavity. It includes a dynamic ring and a static ring, a spring compensation mechanism, and an auxiliary sealing element. The specific sealing is that the end faces of the dynamic ring and the static ring are tightly attached under the action of the spring force and the bellows, forming an extremely thin liquid film to prevent medium leakage. The liquid film also plays a lubricating and cooling role.

[0003] The traditional mechanical seal usually uses metal or rubber bellows as an axial compensation element, which is prone to cracking or aging failure, leading to seal leakage or unstable contact pressure of the sealing surface, uneven wear, and affecting the sealing effect. CONTENT OF THE INVENTION

[0004] The purpose of the present application is to provide a self-adaptive mechanical seal structure for centrifugal pump to solve the technical problems existing in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is to provide a self-adaptive mechanical seal structure for centrifugal pump, which includes a rotating assembly rotating under the drive of the pump shaft, a spring assembly, and a static assembly stationary relative to the pump shaft. The pump shaft is fixedly provided with a pump shaft sleeve. The pump shaft sleeve cooperates with the rotating assembly and the spring assembly. The rotating assembly includes a dynamic ring and a transmission sleeve. The static assembly includes a static ring and a static ring sleeve. The spring assembly includes a spring, a bellows, and a spring cover abutting against the spring. The transmission sleeve fixedly connects the dynamic ring and the bellows. The outer peripheral surface of the bellows is provided with a tight ring elastically abutting against the inner wall of the transmission sleeve.

[0006] Through the above technical solution, the rotating assembly and the static assembly in the mechanical seal structure rotate relative to each other. The end faces of the static ring and the dynamic ring, i.e., the sealing surface, are tightly attached under the action of the spring and the bellows, forming an extremely thin liquid film to prevent medium leakage. The static ring and the dynamic ring are made of graphite, and the transmission sleeve fixedly connects the dynamic ring and the bellows, which can effectively prevent them from being separated and facilitate the rotation of the dynamic ring after the bellows is rotated under the drive of the pump shaft sleeve. In the prior art, the spring is arranged outside the bellows, and in the above technical solution, the bellows and the end of the spring are opposite and not connected with the spring cover. Such arrangement reduces the installation space, facilitates installation, disassembly, replacement and maintenance after damage.

[0007] Optionally, the pump shaft sleeve is provided in a tubular shape; a connecting convex ring is arranged on the outer circumferential surface of the pump shaft sleeve; an annular notch for mounting a sealing rubber ring is arranged on the side surface of the connecting convex ring; a spring cover notch matched with the spring cover is arranged on the outer circumferential surface of the connecting convex ring; and a plurality of fixed threaded grooves are arranged on the spring cover notch.

[0008] Optionally, the spring cover comprises a sheet-shaped bottom ring; a first fixed ring and a second fixed ring are arranged on both sides of the bottom ring; a plurality of circular holes opposite to the fixed threaded grooves are arranged on the second fixed ring; the second fixed ring is matched with the annular elastic cover notch, and a screw is arranged to pass through the circular hole and be connected with the fixed threaded groove; and one end of the spring is arranged in the first fixed ring.

[0009] By the above technical solution, the pump shaft sleeve and the spring cover are fixedly connected, so that when the pump shaft rotates under the driving of the motor, the pump shaft sleeve is driven to rotate through the key connection, the pump shaft sleeve drives the spring cover and the bellows to rotate, the bellows is fixedly connected with the driving sleeve through the tight ring, and thus the rotation driving of the moving ring is realized.

[0010] Optionally, the bellows is in a zigzag shape, comprising an upper end and a lower end, and the upper end is elastically deformed in the horizontal direction of the lower end under the action of external force; the upper end of the bellows abuts against the side surface of the moving ring; the driving sleeve comprises a first backfolding ring opposite to the side surface of the moving ring and a second backfolding ring limiting the upper end of the bellows; a first circumferential ring is arranged between the first backfolding ring and the second backfolding ring; and the second backfolding ring is connected with a second circumferential ring.

[0011] By the above technical solution, the zigzag structure of the bellows forms a spring effect through the folded wave crest, can provide a larger elastic deformation range when the pump shaft sleeve produces axial displacement such as thermal expansion, vibration or installation error, the folded structure can effectively attenuate the vibration energy generated during the operation of the centrifugal pump, avoids the separation of the sealing surface or the fatigue failure of the bellows due to vibration, can buffer the instantaneous impact when starting and stopping or the working condition suddenly changes, and maintains the sealing stability.

[0012] Optionally, the outer circumferential surface of the moving ring and the outer circumferential surface of the upper end of the bellows abut against the inner wall of the first circumferential ring; the tight ring abuts against the inner wall of the second circumferential ring; and the end of the spring away from the spring cover abuts against the second backfolding ring.

[0013] By the above technical solution, the moving ring and the bellows are in abutment with the first backfolding ring and the second backfolding ring, the connection of the two is realized, and the mutual action of the two is facilitated.

[0014] Optionally, an elastic rubber ring is arranged on the inner wall of the lower end of the bellows and the pump shaft sleeve; the pump shaft sleeve is connected with the pump shaft through a key, and a plurality of sealing rubber rings are arranged between the pump shaft sleeve and the pump shaft.

[0015] Through the technical scheme, the elastic rubber ring and the sealing rubber ring both play a sealing role, the key connection is the prior art, and the pump shaft of the centrifugal pump is also connected in a key connection mode.

[0016] The self-adaptive mechanical sealing structure for the centrifugal pump has the beneficial effects of high transmission efficiency, convenient installation and dismounting, saved installation space, stable sealing surface contact pressure and uniform wear through the shape design of the bellows, thereby improving the service life. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only a part of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Fig. 1 is a cross-sectional view of the embodiment of the present application;

[0019] Fig. 2 is a schematic view of the pump shaft sleeve structure of the embodiment of the present application;

[0020] Fig. 3 is a schematic view of the pump shaft sleeve structure of the embodiment of the present application from another angle.

[0021] In the drawings, reference numerals 1, static ring sleeve; 2, static ring; 3, dynamic ring; 4, transmission sleeve; 5, spring; 6, tight ring; 7, bellows; 8, spring cover; 9, pump shaft sleeve; 10, connecting convex ring; 11, annular notch; 12, spring cover notch; 13, fixed threaded groove; 14, bottom ring; 15, first fixed ring; 16, second fixed ring; 17, circular hole; 18, first backfolding ring; 19, second backfolding ring; 20, first week ring; 21, second week ring. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with specific embodiments.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0025] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "several" is two or more, unless otherwise specifically limited.

[0026] As Figs. 1 to 3 shown, the purpose of the embodiments of the present application is to provide a self-adaptive mechanical seal structure for a centrifugal pump to solve the technical problems existing in the prior art.

[0027] To achieve the above-mentioned purpose, the technical solution adopted by the present application is: a self-adaptive mechanical seal structure for a centrifugal pump, comprising a rotating assembly rotating under the driving of a pump shaft, a spring assembly, and a stationary assembly stationary relative to the pump shaft; a pump shaft sleeve 9 is fixedly arranged outside the pump shaft; the pump shaft sleeve 9 cooperates with the rotating assembly and the spring assembly; the rotating assembly comprises a dynamic ring 3 and a transmission sleeve 4; the stationary assembly comprises a static ring 2 and a static ring sleeve 1; the spring assembly comprises a spring 5, a bellows 7, and a spring cover 8 abutting and supporting the spring 5; the transmission sleeve 4 fixedly connects the dynamic ring 3 and the bellows 7; the bellows 7 is provided with a tight ring 6 on the outer circumferential surface and elastically abuts against the inner wall of the transmission sleeve 4.

[0028] Through the above technical solution, the rotating assembly and the stationary assembly in the mechanical seal structure rotate relative to each other, and the end faces of the static ring 2 and the dynamic ring 3, that is, the sealing surfaces, are tightly attached under the action of the spring 5 and the bellows 7, forming an extremely thin liquid film to prevent medium leakage. The static ring 2 and the dynamic ring 3 are made of graphite, and the transmission sleeve 4 fixedly connects the dynamic ring 3 and the bellows 7, which can effectively prevent the two from separating and facilitate the rotation of the dynamic ring 3 after the bellows 7 is driven to rotate by the pump shaft sleeve 9. In the prior art, the spring 5 is arranged outside the bellows 7, and in the above technical solution, the bellows 7 is opposite to the end of the spring 5 and is not connected with the spring cover 8. Such arrangement reduces the installation space, facilitates installation, disassembly, replacement and maintenance after damage.

[0029] Optionally, the pump shaft sleeve 9 is provided in a tubular shape; a connecting convex ring 10 is arranged on the outer circumferential surface of the pump shaft sleeve 9; an annular notch 11 for mounting a sealing rubber ring is arranged on the side surface of the connecting convex ring 10; a spring cover notch 12 matched with the spring cover 8 is arranged on the outer circumferential surface of the connecting convex ring 10; a plurality of fixed threaded grooves 13 are arranged on the spring cover notch 12.

[0030] Optionally, the spring cover 8 comprises a sheet-shaped bottom ring 14; a first fixed ring 15 and a second fixed ring 16 are arranged on both sides of the bottom ring 14; a plurality of circular holes 17 opposite to the fixed threaded grooves 13 are arranged on the second fixed ring 16; the second fixed ring 16 is matched with the annular elastic cover notch, and a screw is arranged to pass through the circular hole 17 and be connected with the fixed threaded groove 13; one end of the spring 5 is arranged in the first fixed ring 15.

[0031] Through the above technical scheme, the pump shaft sleeve 9 and the spring cover 8 are fixedly connected, which facilitates the rotation of the pump shaft sleeve 9 by the key connection mode when the pump shaft rotates under the driving of the motor, and the rotation of the pump shaft sleeve 9 drives the rotation of the spring cover 8 and the bellows 7, and the bellows 7 is fixedly connected with the transmission sleeve 4 through the tight ring 6, thereby realizing the driving of the rotating ring 3.

[0032] Optionally, the bellows 7 is in a zigzag shape, comprising an upper end and a lower end, and is elastically deformed in the horizontal direction from the upper end to the lower end under the action of external force; the upper end of the bellows 7 abuts against the side surface of the rotating ring 3; the transmission sleeve 4 comprises a first backfolding ring 18 opposite to the side surface of the rotating ring 3 and a second backfolding ring 19 limiting the upper end of the bellows 7; a first circumferential ring 20 is arranged between the first backfolding ring 18 and the second backfolding ring 19; the second backfolding ring 19 is connected with a second circumferential ring 21.

[0033] Through the above technical scheme, the zigzag structure of the bellows 7 forms a spring 5 effect through the folded wave crest, can provide a larger elastic deformation range when the pump shaft sleeve 9 produces axial displacement such as thermal expansion, vibration or installation error, the folded structure can effectively attenuate the vibration energy generated during the operation of the centrifugal pump, avoid the separation of the sealing surface or the fatigue failure of the bellows 7 due to vibration, and can buffer the instantaneous impact when starting and stopping or the working condition changes suddenly, thereby maintaining the sealing stability.

[0034] Optionally, the outer circumferential surface of the rotating ring 3 and the outer circumferential surface of the upper end of the bellows 7 abut against the inner wall of the first circumferential ring 20; the tight ring 6 abuts against the inner wall of the second circumferential ring 21; one end of the spring 5 away from the spring cover 8 abuts against the second backfolding ring 19.

[0035] Through the above technical scheme, the rotating ring 3 and the bellows 7 are in abutment with the first backfolding ring 18 and the second backfolding ring 19, thereby realizing the connection of the two, and facilitating the mutual action of the two.

[0036] Optionally, the inner wall of the lower end of the bellows 7 is provided with an elastic rubber ring, and the pump shaft sleeve 9 is in key connection with the pump shaft and is provided with a plurality of sealing rubber rings between the pump shaft sleeve 9 and the pump shaft.

[0037] Through the above technical scheme, the elastic rubber ring and the sealing rubber ring both play a sealing role, the key connection is the prior art, and the pump shaft and the pump shaft of the centrifugal pump are also connected in a key connection mode.

[0038] The application has the beneficial effects that, compared with the prior art, the self-adaptive mechanical sealing structure for the centrifugal pump has the beneficial effects of high transmission efficiency, convenient installation and disassembly, saving installation space, stable contact pressure of the sealing surface through the shape design of the bellows 7, uniform wear, and improved service life.

[0039] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary and is not intended to imply that the scope of the application is limited to these examples; under the idea of the application, the above embodiments or technical features in different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the application as described above. In order to be brief, they are not provided in details.

[0040] The present application is intended to cover all such alternatives, modifications and variations as fall within the broad scope of the appended claims. Accordingly, any and all such modifications, variations or equivalents that fall within the spirit and scope of the application are intended to be included within the scope of the application.

Claims

1. An adaptive mechanical seal structure for a centrifugal pump comprising a rotating assembly that rotates with the pump shaft, a spring assembly, and a stationary assembly that is stationary relative to the pump shaft; characterized by: The pump shaft is externally fixed with a pump shaft sleeve (9); the pump shaft sleeve (9) cooperates with a rotating assembly and a spring assembly; the rotating assembly comprises a dynamic ring (3) and a transmission sleeve (4); the static assembly comprises a static ring (2) and a static ring sleeve (1); the spring assembly comprises a spring (5), a bellows (7), a spring cover (8) abutting against the spring (5) for support; the transmission sleeve (4) fixedly connects the dynamic ring (3) and the bellows (7); the bellows (7) is externally provided with a tight ring (6) elastically abutting against the inner wall of the transmission sleeve (4).

2. The self-adapting mechanical seal structure for a centrifugal pump according to claim 1, characterized in that: The pump shaft sleeve (9) is provided in a tubular shape; the outer periphery of the pump shaft sleeve (9) is provided with a connecting convex ring (10); the side surface of the connecting convex ring (10) is provided with an annular notch (11) for mounting a sealing rubber ring; the outer periphery of the connecting convex ring is provided with a spring cover notch (12) cooperating with the spring cover (8); the spring cover notch (12) is provided with a plurality of fixed threaded grooves (13).

3. The self-adapting mechanical seal structure for a centrifugal pump of claim 2, wherein: The spring cover (8) comprises a sheet-shaped bottom ring (14); the two sides of the bottom ring (14) are provided with a first fixed ring (15) and a second fixed ring (16); the second fixed ring (16) is provided with a plurality of circular holes (17) opposite to the fixed threaded grooves (13); the second fixed ring (16) cooperates with the annular elastic cover notch, and is further provided with a screw passing through the circular hole (17) and connected with the fixed threaded groove (13); one end of the spring (5) is provided in the first fixed ring (15).

4. The self-adapting mechanical seal structure for a centrifugal pump of claim 3, wherein: The cross section of the bellows (7) is in a zigzag shape, comprising an upper end and a lower end, and the upper end elastically deforms in the horizontal direction of the lower end under the action of external force; the upper end of the bellows (7) abuts against the side surface of the dynamic ring (3); the transmission sleeve (4) comprises a first backfolding ring (18) opposite to the side surface of the dynamic ring (3) and a second backfolding ring (19) limiting the upper end of the bellows (7); a first ring (20) is arranged between the first backfolding ring (18) and the second backfolding ring (19); the second backfolding ring (19) is connected with a second ring (21).

5. The self-adapting mechanical seal structure for a centrifugal pump of claim 4, wherein: The outer periphery of the dynamic ring (3) and the outer periphery of the upper end of the bellows (7) abut against the inner wall of the first ring (20); the tight ring (6) abuts against the inner wall of the second ring (21); one end of the spring (5) away from the spring cover (8) abuts against the second backfolding ring (19).

6. The self-adapting mechanical seal structure for a centrifugal pump according to claim 4 or 5, characterized in that: The inner wall of the lower end of the bellows (7) is provided with an elastic rubber ring with the pump shaft sleeve (9); the pump shaft sleeve (9) is keyed connected with the pump shaft, and a plurality of sealing rubber rings are arranged between the pump shaft sleeve (9) and the pump shaft.

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