CN111396559B

CN111396559B - Single-row magnetic mechanical seal

Info

Publication number: CN111396559B
Application number: CN202010248746.XA
Authority: CN
Inventors: 王亮
Original assignee: Guangzhou Xinheng Pump Manufacturing Co ltd
Current assignee: Guangzhou Xinheng Pump Manufacturing Co ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2022-08-23
Anticipated expiration: 2040-03-27
Also published as: CN111396559A

Abstract

The invention discloses a single-row magnetic mechanical seal, which comprises a mounting flange (7), a static ring (5), a dynamic ring (4) and a shaft sleeve (2) positioned on a shaft (1), wherein the upper part of the outer edge of the dynamic ring (4) is provided with an inner magnet ring (42), the inner magnet ring (42) is radially spaced and corresponds to an outer magnet ring (73) with the same poles repelling each other, and a main elastic sealing ring (3) capable of axially jumping in a small range is arranged between the shaft sleeve (2) and the dynamic ring (4). Simple structure and convenient installation and use.

Description

Single-row magnetic mechanical seal

Technical Field

The invention belongs to the technical field of mechanical sealing, and is used for sealing a rotating shaft at a junction of a container insertion opening.

Background

At present, the mechanical seal is widely applied to the rotating shaft seal in places such as a transmission pump, a stirring kettle and the like. During operation, the movable ring rotating along with the shaft and the static ring on the mounting flange are jointed and rubbed to realize radial sealing, the joint of the end face between the movable ring capable of floating and the static ring is mainly under the elastic action of a spring at the back side of the movable ring, the parts such as the spring and the like rotate along with the shaft, the vibration, the fracture and the looseness, the height of multiple springs is not uniform, and the like, so that the sealing effect and the service life of products are influenced, and the installation is also complex. Later the skilled person invented magnetomechanical seals. The magnetic mechanical seal has both attraction and repulsion functions. The mechanical seal with the function of suction force is that the movable ring and the stationary ring are mutually attached and frictionally sealed by virtue of the magnetic attraction force between the permanent magnets, and the unreasonable design has two unreasonable points, wherein the first is that the magnetic attraction force during attachment is determined to be incapable of being adjusted due to the fixed distance of the magnets; the second is that if the moving ring and the static ring are separated by a certain distance, the suction force is reduced, which is not in accordance with the requirement that the homing force should be enhanced as the distance is increased. Therefore, the magnetomechanical seal should be constructed to act as a repulsive force. The "magnetic thrust mechanical seal device ZL 91200941.1" belongs to a structure with the function of repulsion force, but it has at least the following disadvantages: 1) the thrust and distance between the axial thrust magnets are inconvenient to adjust; 2) the space distance occupied by the axial component is still larger, and even certain design requirements of the moving ring are limited, for example, no shaft sleeve design space exists; 3) the load factor is an important parameter in the mechanical seal design, the balance factor problem is not considered in the design, and the pressure resistance and the seal stability are poor in the unbalanced design.

Disclosure of Invention

The single-row magnetic mechanical seal is provided for solving the technical problems.

The invention solves the technical problem, adopts the technical means that the single-row magnetic mechanical seal comprises an installation flange positioned at the opening of a container to be sealed, a static ring arranged at the middle upper part of the installation flange, a movable ring which is tightly attached to the upper part of the static ring and forms a friction pair with the static ring, and a shaft sleeve positioned on a shaft, wherein an inner magnet ring is arranged at the upper part of the outer edge of the movable ring, an outer magnet ring which is opposite to the same pole in a radial direction and corresponds to the inner magnet ring in a spaced manner, the outer magnet ring is positioned on a sliding seat, the sliding seat can be axially fixed on a supporting pipe in a position-selective manner, and a main elastic sealing ring which can axially float in a small range is arranged between the shaft sleeve and the movable ring.

When the sealing device works, the shaft sleeve is fixed on the shaft by means of the positioning screws, the sealing gasket is arranged between the mounting flange and the opening of the container to be sealed and then is fastened and positioned by the bolts, the outer magnet ring is slightly higher than the inner magnet ring, and the downward thrust of the outer magnet ring to the inner magnet ring is adjustable according to the height of the outer magnet ring. In the technical scheme, the repulsion action between the outer magnet ring and the inner magnet ring with the same poles repelling each other replaces the spring force action of the traditional mechanical seal, the occupied space is small, the force is uniform and controllable, the structure is simple, and the defects of the spring in use are overcome. And a main elastic sealing ring which can axially float in a small range is arranged between the shaft sleeve and the movable ring, so that the load coefficient can always meet the requirement of balance design.

There are many methods to keep the moving ring and the shaft sleeve rotating with the shaft synchronously, the direct and simple scheme is to design the transmission pin outside the near lower end of the shaft sleeve, and the axial slot inside the moving ring seat corresponding to the transmission pin. When the shaft rotates, the shaft sleeve rotates along with the shaft sleeve, the driving pin drives the movable ring to rotate, and the movable ring is allowed to have floating freedom, so that the friction end face between the movable ring and the static ring is always attached and sealed.

If the magnetic sealing ring is applied to the occasions with high pressure resistance, the cylindrical surface position of the movable ring seat in contact with the main elastic sealing ring and the middle position of the annular belt of the friction end surface between the movable ring friction piece and the static ring can be designed to be on the same radius, so that the constant specific pressure of the end surface of the friction end surface can be ensured within the range of the action of magnetic force, the sealing performance is ensured, and the service life is also facilitated.

Usually, an auxiliary elastic sealing ring is arranged between the static ring and the mounting flange, and the static ring is compressed and fixed by means of a static ring positioning mechanism, so that the sealing of an interface between the static ring and the mounting flange can be effectively ensured, and the rotation of the static ring is prevented.

The technical scheme of the design can adopt a traditional method to carry out cartridge type design or carry out double-end mechanical seal cartridge type design.

The invention has the advantages that the end face between the movable ring and the static ring is attached by means of the magnetic force of the permanent magnet, thereby solving the problems of vibration, breakage relaxation, uneven heights of multiple springs and the like in the use of the mechanical sealing spring rotating along with the shaft; compared with the magnetic thrust mechanical sealing device ZL91200941.1, the problem that the thrust and the distance between the axial thrust magnets are inconvenient to adjust is solved; the problem that the space distance occupied by the axial component is still large, and even certain design requirements of the moving ring are limited, such as the problem that the design space of a shaft sleeve is not available, is solved; the problem that the load coefficient is close to a balanced design in the mechanical seal design is solved. Therefore, the sealing effect of the product is good, and the service life is long; and because the magnetic force is short-range action, and the spring has a longer structure and an auxiliary structure, compared with the prior art, the invention has simple structure and convenient installation and use.

Drawings

FIG. 1 is a schematic view of a magnetomechanical seal configuration.

FIG. 2 is a partial side view of the support tube of FIG. 1 to show the slide positioning mechanism formed by the slide screw and the slide groove.

In the figure: 1. a shaft; 2. a shaft sleeve; 21; a set screw; 22. a drive pin; 3. a primary elastic seal ring; 4. a moving ring; 41. a moving ring seat; 42. an inner magnet ring; 43. a rotating ring friction member; 5. a stationary ring; 6. a secondary elastic seal ring; 7. installing a flange; 71. supporting a pipe; 72. a sliding seat; 73. an outer magnet ring; 74. a slide positioning mechanism; 741. a sliding screw; 742. a chute; 8. quiet ring positioning mechanism.

Detailed Description

As an implementation mode of single-row magnetic mechanical seal, a sealing gasket is arranged between a mounting flange 7 and a container opening to be sealed and then is fastened and positioned by bolts, a static ring 5 is arranged at the middle upper part of the mounting flange 7, a movable ring 4 which is tightly attached to the upper part of the static ring 5 and forms a friction pair with the static ring 5 and a shaft sleeve 2 which is positioned on a shaft 1 are further included, the shaft sleeve 2 is fixed on the shaft 1 by means of a positioning screw 21, a transmission pin 22 is designed at the outer side of the near lower end of the shaft sleeve 2, an axial groove is designed at the inner side of a movable ring seat 41 which corresponds to the transmission pin, an inner magnet ring 42 is arranged at the upper part of the outer edge of the movable ring 4, an outer magnet ring 73 which is opposite to the same pole and is radially separated from the inner magnet ring 42 is arranged, the outer magnet ring 73 is positioned on a sliding seat 72, the sliding seat 72 is axially positioned at a position which enables the inner magnet ring 42 to be overlapped with a half of the horizontal direction of the outer magnet ring 73 and then is fixed on a supporting pipe 71, the sliding seat 72 is positioned and fastened by means of a nut 71 by means of a sliding screw 741 which is arranged at the lateral side and passes through a sliding groove 742 on the supporting pipe 71 The main elastic sealing ring 3 capable of axially moving in a small range is arranged between the shaft sleeve 2 and the moving ring 4, the cylindrical surface position of the moving ring seat 41 contacted with the main elastic sealing ring 3 and the middle position of a friction end surface annulus between the moving ring friction member 43 and the static ring 5 are on the same radius, the auxiliary elastic sealing ring 6 is arranged between the static ring 5 and the mounting flange 7, the static ring 5 is pressed and fixed by the aid of a static ring positioning mechanism 8, and the static ring positioning mechanism 8 positions a gland on the mounting flange 7 by utilizing a set screw and simultaneously presses the static ring 5.

Claims

1. A single-row magnetic mechanical seal comprises a mounting flange (7) positioned at the opening of a container to be sealed, a static ring (5) arranged at the middle upper part of the mounting flange (7), a movable ring (4) tightly attached to the upper part of the static ring (5) and forming a friction pair with the static ring (5), and a shaft sleeve (2) positioned on a shaft (1), and is characterized in that an inner magnet ring (42) is arranged at the upper part of the outer edge of the movable ring (4), an outer magnet ring (73) which is radially separated from the inner magnet ring (42) and corresponds to the repulsion of like poles is positioned on the outer magnet ring (73), the outer magnet ring (73) is positioned on a sliding seat (72), the sliding seat (72) can be axially fixed on a support pipe (71) in a position selecting manner, and a main elastic sealing ring (3) which can axially float in a small range is arranged between the shaft sleeve (2) and the movable ring (4).

2. The single-row magnetic mechanical seal according to claim 1 is characterized in that a transmission pin (22) is designed on the outer side of the near-lower end of the shaft sleeve (2), and an axial slot is designed on the inner side of the movable ring seat (41) at the corresponding position.

3. A single-row magnetomechanical seal according to claim 2, characterised in that the cylindrical surface of the moving ring seat (41) in contact with the primary elastic sealing ring (3) is located on the same radius as the middle of the friction end surface annulus between the moving ring friction member (43) and the stationary ring (5).

4. A single row magnetomechanical seal according to claim 1, characterised in that the sleeve (2) is fixed to the shaft (1) by means of a set screw (21).

5. A single row magnetomechanical seal according to claim 1, characterised in that a secondary resilient sealing ring (6) is arranged between the stationary ring (5) and the mounting flange (7), pressing and fixing the stationary ring (5) by means of a stationary ring positioning means (8).

6. The single row magnetomechanical seal of claim 1, wherein the sliding seat (72) is secured in position by a nut after passing through a slide slot (742) in the support tube (71) by means of a slide screw (741) mounted laterally thereto.