Low-friction self-lubricating high-pressure sealing system for rotating shaft

Abstract

The low-friction high-pressure sealing system is characterized in that the low-friction high-pressure sealing system comprises a lip seal, a supporting ring (3), a pressing ring (4), the rotating shaft (5) and a cavity (6), and the lip seal comprises a base body part (1) made of a rubber fiber composite material and a lip part (2) made of a self-lubricating rubber fiber composite material; the supporting ring (3) and the pressing ring (4) fix the lip seal in the axial direction, the lip portion (2) made of the self-lubricating rubber fiber composite material makes contact with the rotating shaft (5), and the rotating shaft (5) is located in the cavity (6). The sealing system is reliable in performance, long in service life, convenient to install, good in universality and interchangeability and particularly suitable for occasions with large sealing pressure such as shield tunneling machines and ship tail shaft sealing.

Description

Technical Field

[0001] The invention relates to the technical field of sealing, and in particular to a low-friction and high-pressure sealing system for a rotating shaft. Background Art

[0002] The main drive seal of the shield machine is the core component of the shield machine. Once there is a problem with the seal, the shield machine will be paralyzed and unable to operate. The seal of the shield machine is difficult to replace and the replacement cost is very high. Therefore, the sealing system is very important.

[0003] At present, shield machines are facing the situation of high water pressure during construction at great depths, which requires higher pressure resistance of the sealing system. The maximum design pressure resistance of shield seals is currently 10 bar. The water pressure is high during construction at great depths, sometimes reaching 100 bar, and the existing sealing system cannot meet the requirements.

[0004] Therefore, it is necessary to develop a high-pressure sealing system that adapts to this working condition. Summary of the invention

[0005] Technical solution:

[0006] In order to solve the above problems, the present invention adopts a new design scheme. The present invention relates to a low-friction high-pressure sealing system for a rotating shaft, characterized by comprising a lip seal, a support ring (3), a pressure ring (4), a rotating shaft (5) and a cavity (6), wherein the lip seal comprises a base part (1) of a rubber fiber composite material and a lip part (2) of a self-lubricating rubber fiber composite material,

[0007] The support ring (3) and the pressure ring (4) fix the lip seal in the axial direction.

[0008] The lip portion (2) of the self-lubricating rubber fiber composite material is in contact with the rotating shaft (5), and the rotating shaft (5) is located inside the cavity (6).

[0009] Preferably, the number of the lip seals, support rings (3) and pressure rings (4) is more than two, and they are arranged at intervals along the axial direction inside the cavity (6), so that a good sealing effect can be achieved through a multiple sealing structure.

[0010] Preferably, the two lip-shaped sealing lips located axially on the outermost sides of the cavity (6) are arranged in opposite directions, so as to achieve a bidirectional sealing effect.

[0011] Preferably, the interior of the rotating shaft (5) is hollow, and cooling water can be passed through to cool the low-friction self-lubricating high-pressure seal.

[0012] The base part (1) of the rubber fiber composite material and the lip part (2) of the self-lubricating rubber fiber composite material are bonded into a whole by vulcanization. Fibers are added to the base part (1) of the rubber fiber composite material, thereby increasing the elastic modulus of the lip seal and improving the compressive resistance of the sealing lip. Fiber material is added to the lip part (2) of the self-lubricating rubber fiber composite material to increase the material elastic modulus, and self-lubricating material is added to reduce the friction coefficient of the sealing lip, thereby reducing the friction temperature rise when the lip and the rotating shaft (5) move relative to each other.

[0013] The support ring (3) supports the sealing lip, further improving the high-pressure resistance of the seal. The support ring (3), the pressure ring (4) and the cavity (6) jointly fix the lip seal. Cooling water passes through the rotating shaft (5) to cool the sealing lip. In this way, it can be ensured that the seal is not damaged under high pressure. When the rotating shaft (5) rotates under high pressure, the temperature rise of the sealing lip is within a controllable range, thereby improving the service life of the sealing lip. The sealing system of the present invention has reliable performance, long service life, easy installation, good versatility and interchangeability, and is particularly suitable for occasions with high sealing pressure such as shield machines and ship tail shaft seals.

[0014] In view of the deficiencies in the prior art, the present invention provides a low-friction, high-pressure sealing system for a rotating shaft. The sealing structure can be used to solve the problem of poor pressure resistance of traditional large rotating shaft seals.

[0015] The present invention is further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 :Low friction self-lubricating high pressure sealing system composition

[0017] Figure 2 :Cross-section of low-friction self-lubricating high-pressure seal semi-finished product

[0018] Figure 3 :Low friction self-lubricating high pressure sealing system installation diagram

[0019] in:

[0020] Figure 1 Middle: 1. Rubber sealing fiber reinforced part, 2. Rubber sealing fiber reinforced self-lubricating low friction part, 3. Support ring, 4. Pressure ring, 5. Rotating shaft, 6. Cavity.

[0021] Figure 2 Middle: 1. Rubber sealing fiber reinforced part, 2. Rubber sealing fiber reinforced self-lubricating low friction part.

[0022] Figure 3Middle: 1. Rubber sealing fiber reinforced part, 2. Rubber sealing fiber reinforced self-lubricating low friction part, 3. Support ring, 4. Pressure ring, 5. Rotating shaft, 6. Cavity. DETAILED DESCRIPTION

[0023] Example:

[0024] A low-friction, high-pressure sealing system for a rotating shaft comprises a lip seal, a support ring (3), a pressure ring (4), a rotating shaft (5) and a cavity (6), wherein the lip seal comprises a base portion (1) of a rubber fiber composite material and a lip portion (2) of a self-lubricating rubber fiber composite material.

[0025] The support ring (3) and the pressure ring (4) fix the lip seal in the axial direction.

[0026] The lip portion (2) of the self-lubricating rubber fiber composite material is in contact with the rotating shaft (5), and the rotating shaft (5) is located inside the cavity (6).

[0027] The preparation method of the low-friction high-pressure sealing system.

[0028] The first step is rubber mixing. The mixed rubber used for the base part (1) of the rubber fiber composite material and the lip part (2) of the self-lubricating rubber fiber composite material is mixed by using an internal mixer and an open mixer.

[0029] Among them, the types of reinforcing fibers include aramid, nylon, carbon fiber, carbon nanotubes, etc., and the types of self-lubricants include polytetrafluoroethylene, polyetheretherketone, molybdenum disulfide, graphite, etc.

[0030] The second step is co-extrusion. Using an extruder, the mixed rubber used for the base part (1) of the rubber fiber composite material and the lip part (2) of the self-lubricating rubber fiber composite material are co-extruded. The cross section of the extruded material is as follows: Figure 2 shown.

[0031] The third step is to use a flat vulcanizer and a mold to vulcanize a low-friction, high-pressure sealing product. The product can be processed by either integral compression vulcanization or segmented vulcanization.

[0032] The fourth step is to machine the support ring (3), the pressure ring (4), the rotating shaft (5) and the cavity (6).

[0033] Step 5: Assembly: In the cavity (6), the support ring (3) and the pressure ring (4) fix the lip seal in the axial direction, and the lip portion (2) of the self-lubricating rubber fiber composite material contacts the rotating shaft (5).

[0034] Preferably, the number of the lip seals, support rings (3) and pressure rings (4) is more than two, and they are arranged at intervals along the axial direction inside the cavity (6), so that a good sealing effect can be achieved through a multiple sealing structure.

[0035] Preferably, the two lip-shaped sealing lips located axially on the outermost sides of the cavity (6) are arranged in opposite directions, so as to achieve a bidirectional sealing effect.

[0036] Preferably, the rotating shaft (5) is hollow and has cooling water flowing inside to cool the low-friction self-lubricating high-pressure seal.

[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 low friction high pressure sealing system for a rotating shaft, characterized in that It includes a lip seal, a support ring (3), a pressure ring (4), a rotating shaft (5) and a cavity (6). The lip seal comprises a base portion (1) made of a rubber fiber composite material and a lip portion (2) made of a self-lubricating rubber fiber composite material. The support ring (3) and the pressure ring (4) fix the lip seal in the axial direction. The lip portion (2) of the self-lubricating rubber fiber composite material is in contact with the rotating shaft (5), The rotating shaft (5) is located inside the cavity (6).

2. According to the sealing system of claim 1, the number of the lip seal, the support ring (3) and the pressure ring (4) is more than two, and they are arranged at intervals along the axial direction inside the cavity (6).

3. The sealing system according to claim 2, wherein the two lip-shaped sealing lips located axially on the outermost sides inside the cavity (6) are arranged in opposite directions.

4. The sealing system according to claim 1, wherein the interior of the rotating shaft (5) is hollow.

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