Magnetic confinement large-diameter lip sealing system for rotating shaft

Abstract

The magnetic confinement large-diameter lip-shaped sealing system is characterized by comprising a rubber seal (1), a magnetic rubber ring (2), a supporting ring (3), a rotating shaft (4) and a sealing cavity (5), the magnetic rubber ring (2) is embedded in the rubber seal (1), the supporting ring (3) is arranged in the sealing cavity (5), and the rotating shaft (4) is arranged in the sealing cavity (5). And the rubber seal (1) is fixed between two adjacent support rings (3). Proper radial force can be provided by controlling the magnetic force of the magnetic rubber ring (2), when the lip is abraded, the magnetic rubber ring (2) is closer to a rotating shaft (4), the magnetic force is increased, the radial force reduced due to abrasion of the lip is compensated, and then the radial force of the lip of the oil seal is kept at a relatively stable level for a long time.

Description

Technical Field

[0001] The invention relates to the technical field of sealing, and in particular to a magnetically constrained large-diameter lip sealing system for a rotating shaft. Background Art

[0002] The main drive seal of the shield machine is the "immune system" of the shield machine. Once a leak is found in the main drive seal, the shield machine will be paralyzed and unable to operate. In addition, the cost of replacing the shield machine seal is high. Therefore, the life and reliability of the main drive seal of the shield machine are very important.

[0003] The radial force of the main drive seal lip of the shield machine in service will gradually decrease as the seal lip wears, thereby reducing the reliability and service life of the seal. Therefore, it is necessary to develop a sealing system that can reduce the radial force drop after the seal lip wears. Summary of the invention

[0004] Technical solution:

[0005] In order to solve the above problems, the present invention adopts a new design scheme. The present invention relates to a magnetically constrained large-diameter lip seal system for a rotating shaft, characterized in that it comprises a rubber seal (1), a magnetic rubber ring (2), a support ring (3), a rotating shaft (4) and a sealing cavity (5).

[0006] The rubber seal (1) is embedded with the magnetic rubber ring (2).

[0007] The support ring (3) is arranged inside the sealing cavity (5), and the rubber seal (1) is fixed between two adjacent support rings (3).

[0008] Preferably, the magnetic rubber ring (2) is located in the lip area of ​​the rubber seal (1).

[0009] Preferably, the number of the rubber seals (1) and the support rings (3) is more than two, and they are arranged at intervals along the axial direction of the sealing cavity (5).

[0010] Preferably, the lips of the two rubber seals (1) located axially outermost in the sealing cavity (5) are arranged in opposite directions.

[0011] After the lip of the rubber seal (1) is worn, the magnetic rubber ring (2) will be closer to the rotating shaft (4) to compensate for the radial force reduced due to the wear of the lip.

[0012] The magnetic rubber ring (2) is a soft magnet with a rubber matrix filled with a large amount of magnetic powder.

[0013] The semi-finished rubber seal (1) and the magnetic rubber ring (2) are co-extruded by an extruder, so that the relative position of the magnetic rubber ring (2) in the rubber seal (1) can be ensured, and then vulcanized using a mold and a flat vulcanizer. In this way, the rubber seal (1) and the magnetic rubber ring (2) are thermally bonded into a whole during vulcanization.

[0014] By adjusting the type and content of the magnetic powder, the magnetic force of the magnetic rubber ring (2) can be controlled to provide a suitable radial force. When the lip is worn, the soft magnetic confinement ring (2) will be closer to the rotating shaft (4), and the magnetic force will increase to compensate for the radial force reduced due to lip wear, thereby maintaining the radial force of the oil seal lip at a relatively stable level for a long time.

[0015] The purpose of the present invention is to address the deficiencies in the prior art and to provide a magnetically constrained large-diameter lip seal system for a rotating shaft. The sealing structure can be used to solve the problem that, with the wear of the sealing lip, the radial force of the seal decreases too quickly, resulting in a seal service life that is less than expected in traditional large rotating shaft lip seals.

[0016] The sealing system of the present invention has reliable performance, long service life, convenient installation, good versatility and interchangeability, and is particularly suitable for situations with high sealing requirements such as shield machines and ship tail shaft seals.

[0017] The present invention is further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 : Magnetic restraint large diameter lip seal system structure diagram

[0019] Figure 2 : Cross-section of a semi-finished product of a magnetically constrained large diameter lip seal

[0020] Figure 3 :Application example of magnetically constrained large diameter lip seal system

[0021] in:

[0022] Figure 1 Middle: 1. Rubber seal, 2. Soft magnetic confinement ring, 3. Support ring, 4. Rotating shaft, 5. Outer wall of sealing cavity.

[0023] Figure 2 Middle: 1. Rubber seal, 2. Soft magnetic confinement ring.

[0024] Figure 3 Middle: 1. Rubber seal, 2. Soft magnetic confinement ring, 3. Support ring, 4. Rotating shaft, 5. Outer wall of sealing cavity. DETAILED DESCRIPTION

[0025] Example:

[0026] A magnetically constrained large-diameter lip seal system for a rotating shaft comprises a rubber seal (1), a magnetic rubber ring (2), a support ring (3), a rotating shaft (4) and a sealing cavity (5); the rubber seal (1) is embedded with the magnetic rubber ring (2); the support ring (3) is arranged inside the sealing cavity (5); and the rubber seal (1) is fixed between two adjacent support rings (3).

[0027] The preparation method of the magnetically constrained large-diameter lip seal system.

[0028] The first step is rubber refining. The mixed rubber used for the rubber seal (1) is mixed using an internal mixer and an open mixer. The main body of the magnetic rubber ring (2) is rubber, which is filled with a large amount of magnetic powder and processed using a rubber mixing process. The mixed rubber used for the magnetic rubber ring (2) is mixed using an internal mixer and an open mixer.

[0029] The second step is co-extrusion. Using an extruder, the mixed rubber used for the rubber seal (1) and the mixed rubber used for the magnetic rubber ring (2) are co-extruded to form a structure in which the rubber seal (1) is embedded with the magnetic rubber ring (2). The extruded cross section is as follows: Figure 2 shown.

[0030] The third step is to use a flat vulcanizer and a mold to vulcanize the magnetically constrained large-diameter lip seal product, which can be processed by integral molding vulcanization or segmented vulcanization.

[0031] The fourth step is to use machining to produce the support ring (3), the rotating shaft (4) and the sealing cavity (5).

[0032] The fifth step is to assemble the sealing cavity (5) in such a way that the rubber seal (1) is fixed between two adjacent support rings (3).

[0033] Preferably, the magnetic rubber ring (2) is located in the lip area of ​​the rubber seal (1), so as to better compensate for the radial force reduced by lip wear.

[0034] Preferably, the number of the rubber seal (1) and the support ring (3) is more than two, and they are arranged at intervals along the axial direction of the sealing cavity (5) to provide a better sealing effect.

[0035] Preferably, the lips of the two rubber seals (1) located at the axially outermost sides of the sealing cavity (5) are arranged in opposite directions to achieve an axial bidirectional sealing effect.

[0036] The magnetically constrained large-diameter lip seal system of the present invention can provide an appropriate radial force. When the lip is worn, the magnetic rubber ring (2) will be closer to the rotating shaft (4), and the magnetic force will increase to compensate for the radial force reduced due to lip wear, thereby maintaining the radial force of the oil seal lip at a relatively stable level for a long time.

[0037] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A magnetically constrained large diameter lip seal system for a rotating shaft, characterized in that It comprises a rubber seal (1), a magnetic rubber ring (2), a support ring (3), a rotating shaft (4) and a sealing cavity (5). The rubber seal (1) is embedded with the magnetic rubber ring (2). The support ring (3) is arranged inside the sealing cavity (5), and the rubber seal (1) is fixed between two adjacent support rings (3).

2. The sealing system according to claim 1, wherein the magnetic rubber ring (2) is located in the lip area of ​​the rubber seal (1).

3. According to the sealing system of claim 1, the number of the rubber seal (1) and the support ring (3) is more than two, and they are arranged at intervals along the axial direction of the sealing cavity (5).

4. The sealing system according to claim 3, wherein the lips of the two rubber seals (1) located axially outermost in the sealing cavity (5) are arranged in opposite directions.

5. According to the sealing system of claim 1, after the lip of the rubber seal (1) is worn, the magnetic rubber ring (2) will be closer to the rotating shaft (4) to compensate for the radial force reduced due to the wear of the lip.

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