Medium-pressure mechanical seal of vertical centrifugal pump

Abstract

The utility model relates to the technical field of centrifugal pumps, and discloses a vertical centrifugal pump medium-pressure mechanical seal which comprises a mechanical seal seat, a first limiting sleeve is installed at the upper end of the mechanical seal seat, a spring is installed between the mechanical seal seat and the first limiting sleeve, and a dynamic friction pair is movably connected into the upper end of the first limiting sleeve in a sleeved mode. And an O-shaped sealing ring is mounted between the first limiting sleeve and the dynamic friction pair. According to the medium-pressure mechanical seal of the vertical centrifugal pump, when the spring pushes the first limiting sleeve to move upwards, the first limiting sleeve and the dynamic friction pair can be controlled to be attached to keep tightness, meanwhile, the O-shaped sealing ring is controlled to be installed outside the output shaft, and the mechanical seal base, the first limiting sleeve and the dynamic friction pair synchronously rotate along with rotation of the output shaft; the sealing performance can be kept under the action of the O-shaped sealing ring, meanwhile, the static friction pair is installed on the limiting device, and the sealing sleeve seals the end of the output shaft, so that convenience is kept during installation, and the overall sealing performance of the pump body is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal pumps, in particular to a medium-pressure mechanical seal for a vertical centrifugal pump. Background Art

[0002] The main control parameters selected for vertical centrifugal pumps are the pump's flow rate Q, head H, efficiency η, power, speed n, working pressure, required cavitation head (NPSH), etc. An output shaft is installed at one end of the centrifugal pump. At the same time, the centrifugal pump will drive the circulation of liquid when in use, and high-speed rotation of the output shaft will cause liquid leakage. In order to prevent the liquid from flowing to the output end, a mechanical seal will be installed on the outside of the output shaft to improve its sealing performance.

[0003] Generally, a mechanical seal refers to a device for preventing fluid leakage, which is composed of at least a pair of end faces perpendicular to the axis of rotation, which remain in contact and slide relative to each other under the action of fluid pressure and the elastic force (or magnetic force) of the compensation mechanism and the cooperation of auxiliary seals. There is a sealing structure that needs to use a spring to assist it in maintaining a tight fit, but it mainly ensures that the sealing ring and the outside of the output shaft remain in a tight fit. Therefore, when the output shaft rotates, it will cause wear to the sealing ring. Therefore, the sealing ring needs to be replaced regularly. However, in conventional mechanical seal structures, in order to ensure the stability of the mechanical seal during installation, the position between the structures is fixed by a packaging structure, which leads to a waste of time when the sealing ring is replaced later, affecting the efficiency of the installation and replacement of the packaging structure. Therefore, we have proposed a medium-pressure mechanical seal for a vertical centrifugal pump. Utility Model Content

[0004] In response to the shortcomings of the existing medium-pressure mechanical seals in vertical centrifugal pumps, the utility model provides a medium-pressure mechanical seal in a vertical centrifugal pump, which is limited by sequential sleeve connection between structures, and at the same time, the O-ring is arranged between the first limit sleeve and the dynamic friction pair. By controlling the limit pin to be sleeved on the outside of the ring, and rotating the fastening bolt at the same time, the fastening bolt drives the dynamic friction pair arranged on the upper part of the first limit sleeve, ensuring its stability during installation. However, when the O-ring is subsequently replaced, the limit pin and the ring can drive the dynamic friction pair and the first limit sleeve to be disassembled, thereby solving the problems raised in the above-mentioned background technology.

[0005] The utility model provides the following technical solution: a medium-pressure mechanical seal for a vertical centrifugal pump, comprising a mechanical seal seat, a first limiting sleeve being installed on the upper end of the mechanical seal seat, a spring being installed between the mechanical seal seat and the first limiting sleeve, a dynamic friction pair being movably sleeved internally at the upper end of the first limiting sleeve, an O-ring being installed between the first limiting sleeve and the dynamic friction pair, a static friction pair being movably sleeved at the upper end of the dynamic friction pair, and a sealing sleeve being movably sleeved externally at the static friction pair.

[0006] Preferably, a dynamic ring is fixedly connected to the upper portion of the mechanical seal seat, a second limiting sleeve is fixedly connected to the lower end of the first limiting sleeve, and the dynamic ring and the second limiting sleeve are sleeved and limited with each other.

[0007] Preferably, a mounting plate is installed on the upper portion of the dynamic ring via a pull rope, and the mounting plate is installed inside the lower end of the first limiting sleeve.

[0008] Preferably, a telescopic sleeve is provided on the inner side of the mechanical seal seat and the first limiting sleeve, and the telescopic sleeve is provided on the inner side of the spring.

[0009] Preferably, the external fixed connection of the dynamic friction pair is a limit pin, the limit pin is movably sleeved inside the groove opened at the upper end of the first limit sleeve, the interior of the first limit sleeve is movably sleeved with a ring, the interior of the limit pin is installed with a fastening bolt, the ring is movably sleeved inside the limit pin, and the fastening bolt passes through the interior of the limit pin and the ring in turn.

[0010] Preferably, balls are movably sleeved on the inner side of the static friction pair, and the balls are arranged at equal intervals on the inner side of the static friction pair.

[0011] Preferably, the output shaft of the centrifugal pump passes through the interior of the mechanical seal seat, and a limiting device is installed at the lower end of the mechanical seal seat, which is clamped on the outside of the output shaft. A limiting groove is installed at the upper end of the static friction pair, and the ball installed on the inner side of the static friction pair is fitted on the outside of the output shaft.

[0012] Compared with the existing medium-pressure mechanical seal of vertical centrifugal pumps, the utility model has the following beneficial effects:

[0013] 1. The medium-pressure mechanical seal of the vertical centrifugal pump can control the first limit sleeve and the dynamic friction pair to fit tightly when the spring pushes the first limit sleeve upward. At the same time, the O-ring is controlled to be installed on the outside of the output shaft. The mechanical seal seat, the first limit sleeve and the dynamic friction pair rotate synchronously with the rotation of the output shaft. The sealing can be maintained under the action of the O-ring. At the same time, the static friction pair is installed on the limit device, and the sealing sleeve seals the end of the output shaft, so that the installation is convenient and the overall sealing of the pump body is improved.

[0014] 2. The medium-pressure mechanical seal of the vertical centrifugal pump is equipped with a limit pin on the side of the dynamic friction pair. The limit pin is sleeved on the outside of the ring and fixed by tightening bolts. This ensures that the dynamic friction pair and the first limit sleeve maintain tightness after positioning, and prevents the spring from losing elasticity, causing the first limit sleeve to slide downward, thereby causing the first limit sleeve and the dynamic friction pair to be misaligned, thereby affecting their sealing. When controlling the seal, the stability of the installation positioning is improved, and the service life of the pump is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the main structure of the utility model;

[0016] Figure 2 This is a schematic diagram of the explosion structure of the main body of the utility model;

[0017] Figure 3 This is a schematic diagram of the cross-sectional structure of the main body of the utility model;

[0018] Figure 4 This is an enlarged structural diagram of point A of the present utility model.

[0019] In the figure: 1. Machine seal seat; 2. Dynamic ring; 3. First limit sleeve; 4. Second limit sleeve; 5. Spring; 6. Telescopic sleeve; 7. Pull rope; 8. Mounting plate; 9. Dynamic friction pair; 10. O-ring; 11. Limit pin; 12. Ring; 13. Fastening bolt; 14. Static friction pair; 15. Sealing sleeve; 16. Ball. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 A medium-pressure mechanical seal for a vertical centrifugal pump includes a machine seal seat 1. A first limiting sleeve 3 is installed on the upper end of the machine seal seat 1. A spring 5 is installed between the machine seal seat 1 and the first limiting sleeve 3. The spring 5 pushes the first limiting sleeve 3 to move upward. The internal movable sleeve of the upper end of the first limiting sleeve 3 is connected with a dynamic friction pair 9. An O-ring 10 is installed between the first limiting sleeve 3 and the dynamic friction pair 9. The O-ring 10 is clamped and installed between the first limiting sleeve 3 and the dynamic friction pair 9, and the O-ring 10 is arranged on the outside of the output shaft, thereby improving the sealing performance. The upper end of the dynamic friction pair 9 is movably sleeved with a static friction pair 14, and the external movable sleeve of the static friction pair 14 is connected with a sealing sleeve 15. The sealing sleeve 15 further improves the sealing performance.

[0022] Among them, the upper part of the machine seal seat 1 is fixedly connected with a dynamic ring 2, and the lower end of the first limit sleeve 3 is fixedly connected with a second limit sleeve 4, and the dynamic ring 2 and the second limit sleeve 4 are mutually socketed and limited. The machine seal seat 1 and the first limit sleeve 3 are mutually socketed and limited. After the machine seal seat 1 and the static friction pair 14 are respectively installed on two groups of limit devices, the position between the machine seal seat 1 and the first limit sleeve 3 can be split at the same time, which is convenient for the installation of the spring 5. At the same time, the dynamic ring 2 and the second limit sleeve 4 are mutually socketed and limited. When the machine seal seat 1 is controlled to rotate, the first limit sleeve 3 can be driven to rotate synchronously, and the convenience of installing and adjusting the spring 5 is improved.

[0023] Among them, the upper part of the dynamic ring 2 is installed with a mounting plate 8 through a pull rope 7, and the mounting plate 8 is installed inside the lower end of the first limit sleeve 3. The mounting plate 8 is installed through the top of the pull rope 7, and the mounting plate 8 is clamped on the outside of the first limit sleeve 3, that is, the pull rope 7 provides a pulling force to the position between the machine seal seat 1 and the first limit sleeve 3 to prevent the machine seal seat 1 from rotating too fast, resulting in excessive torque between the machine seal seat 1 and the first limit sleeve 3, resulting in misalignment and twisting between the dynamic ring 2 and the second limit sleeve 4.

[0024] Among them, a telescopic sleeve 6 is provided on the inner side of the machine seal seat 1 and the first limit sleeve 3. The telescopic sleeve 6 is provided on the inner side of the spring 5 and is installed between the machine seal seat 1 and the first limit sleeve 3 through the spring 5. The spring 5 pushes the first limit sleeve 3 to move upward. At the same time, a telescopic sleeve 6 is installed on the inner side of the spring 5. The telescopic sleeve 6 protects the position of the spring 5 to prevent the spring 5 from contacting the output shaft. When the output shaft rotates, the position of the spring will be offset, thereby reducing the service life of the sealing structure.

[0025] The outer part of the dynamic friction pair 9 is fixedly connected to the limit pin 11, and the limit pin 11 is movably sleeved in the inner part of the groove opened at the upper end of the first limit sleeve 3. The inner part of the first limit sleeve 3 is movably sleeved with a ring 12, and a fastening bolt 13 is installed inside the limit pin 11. The ring 12 is movably sleeved in the inner part of the limit pin 11, and the fastening bolt 13 passes through the inner parts of the limit pin 11 and the ring 12 in turn. The limit pin 11 is fixedly connected to the outer part of the dynamic friction pair 9 to control the limit pin 11 to be movably sleeved in the inner part of the groove opened at the upper end of the first limit sleeve 3. At the same time, the ring 12 installed inside the first limit sleeve 3 is set inside the lower end of the limit pin 11. Turn to the fastening bolt 13 to splice and fix the position between the limit pin 11 and the ring 12, that is, the limit pin 11 maintains stability when the upper end position of the first limit sleeve 3 moves, so that it is convenient to drive the O-ring 10 to be installed between the first limit sleeve 3 and the dynamic friction pair 9.

[0026] Among them, the inner side of the static friction pair 14 is movably sleeved with balls 16, and the balls 16 are arranged at equal intervals on the inner side of the static friction pair 14. The balls 16 are installed on the inner side of the static friction pair 14 to control the contact between the balls 16 and the output shaft, that is, the machine seal seat 1, the first limit sleeve 3 and the dynamic friction pair 9 rotate synchronously with the rotation of the output shaft, and the static friction pair 14 remains stationary. The balls 16 can reduce the friction resistance when the output shaft rotates.

[0027] Among them, the output shaft of the centrifugal pump passes through the interior of the mechanical seal seat 1, and a limiting device is installed at the lower end of the mechanical seal seat 1, which is clamped on the outside of the output shaft. A limiting groove is installed at the upper end of the static friction pair 14, and the ball 16 installed on the inner side of the static friction pair 14 is fitted on the outside of the output shaft. By installing it on the output shaft, one end of the sealing structure is installed on the output shaft, and the other end is installed on the limiting device. The O-ring 10 is tightly fitted on the outside of the output shaft under the action of pressure, thereby improving the sealing performance of the output shaft when it rotates.

[0028] Working principle: When in use, the output shaft is sleeved on the outside of the machine seal seat 1, and a first limit sleeve 3 is installed on the outside of the machine seal seat 1. The spring 5 is arranged between the machine seal seat 1 and the first limit sleeve 3. The upper end of the first limit sleeve 3 is successively installed with an O-ring 10 and a dynamic friction pair 9, and the static friction pair 14 is installed on the limit device. Under the elastic action of the spring 5, the O-ring 10 is controlled to fit tightly on the outside of the output shaft, thereby ensuring the sealing of the centrifugal pump and improving the convenience during installation.

[0029] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A medium-pressure mechanical seal for a vertical centrifugal pump, comprising a seal seat (1), characterized in that: A first limiting sleeve (3) is installed at the upper end of the mechanical seal seat (1), a spring (5) is installed between the mechanical seal seat (1) and the first limiting sleeve (3), a dynamic friction pair (9) is movably sleeved inside the upper end of the first limiting sleeve (3), an O-type sealing ring (10) is installed between the first limiting sleeve (3) and the dynamic friction pair (9), the upper end of the dynamic friction pair (9) is movably sleeved with a static friction pair (14), and the outer movably sleeve of the static friction pair (14) is connected to a sealing sleeve (15).

2. A medium-pressure mechanical seal for a vertical centrifugal pump according to claim 1, characterized in that: The upper portion of the mechanical seal seat (1) is fixedly connected to a dynamic ring (2), the lower end of the first limiting sleeve (3) is fixedly connected to a second limiting sleeve (4), and the dynamic ring (2) and the second limiting sleeve (4) are mutually sleeved and limited.

3. A medium-pressure mechanical seal for a vertical centrifugal pump according to claim 2, characterized in that: The upper portion of the dynamic ring (2) is mounted with a mounting plate (8) via a pull rope (7), and the mounting plate (8) is mounted inside the lower end of the first limiting sleeve (3).

4. A medium-pressure mechanical seal for a vertical centrifugal pump according to claim 1, characterized in that: A telescopic sleeve (6) is provided on the inner sides of the mechanical seal seat (1) and the first limiting sleeve (3), and the telescopic sleeve (6) is provided on the inner side of the spring (5).

5. A medium-pressure mechanical seal for a vertical centrifugal pump according to claim 1, characterized in that: The outside of the dynamic friction pair (9) is fixedly connected to a limit pin (11), and the limit pin (11) is movably sleeved inside a groove provided at the upper end of the first limit sleeve (3). The inside of the first limit sleeve (3) is movably sleeved with a circular ring (12), and a fastening bolt (13) is installed inside the limit pin (11), and the circular ring (12) is movably sleeved inside the limit pin (11), and the fastening bolt (13) passes through the inside of the limit pin (11) and the circular ring (12) in sequence.

6. A medium-pressure mechanical seal for a vertical centrifugal pump according to claim 1, characterized in that: The inner side of the static friction pair (14) is movably sleeved with balls (16), and the balls (16) are arranged at equal intervals on the inner side of the static friction pair (14).

7. A medium-pressure mechanical seal for a vertical centrifugal pump according to claim 1, characterized in that: The output shaft of the centrifugal pump passes through the interior of the mechanical seal seat (1), and a limiting device is installed at the lower end of the mechanical seal seat (1), and the limiting device is clamped on the outside of the output shaft. The upper end of the static friction pair (14) is installed with a limiting groove, and the ball (16) installed on the inner side of the static friction pair (14) is fitted on the outside of the output shaft.

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