Radial seal structure and method of installation

Abstract

The application provides a radial sealing structure and mounting method, which comprises the following steps: preparing for sealing, placing the sealing cover and the sealing cylinder in the vacuum box after aligning, vacuumizing and pressure-keeping of the vacuum box, inflating the vacuum box to mount the sealing cover in place, and mounting and tightening the connecting screw. The application adopts a special mounting method, which can effectively reduce the mounting difficulty of the sealing structure, ensure the mounting of the sealing structure in place, maintain the pre-tightening force of the mounting screw, and prevent the sealing structure from losing sealing effect due to the reduction of the pre-tightening force.

Description

Technical Field

[0001] This invention relates to a radial sealing structure and its installation method, belonging to the technical field of sealing connection structure. Background Technology

[0002] Currently, my country's deep-sea resource development projects are experiencing explosive growth, with a large number of high-precision sensors and equipment being deployed underwater. Sealing structures are crucial for ensuring the normal operation of these devices, and high-grade radial sealing structures are the most widely used. For example... Figure 1 As shown, the radial sealing structure includes a sealing cylinder, a sealing cover, and a sealing connector. Multiple sealing rings are provided between the sealing cylinder and the sealing cover. The devices and equipment are installed in the sealing cavity formed by the sealing cylinder and the sealing cover.

[0003] Because of the high sealing rating of the radial sealing structure, the air compressed within the sealing cavity is difficult to expel during assembly. Furthermore, the assembly process of the radial sealing structure requires a relatively long axial stroke. This situation presents two problems: Firstly, assembling the sealing components into position is extremely difficult (for a 200mm diameter part, the atmospheric pressure to overcome can reach hundreds of megapascals). Secondly, a portion of the preload of the assembly screws is used to counteract the force caused by the pressure difference between the inside and outside of the sealing cavity. In this case, if the product is used for deep-sea operations, the increased external environmental pressure will cause a decrease in the preload of the assembly screws.

[0004] After these products are assembled, even without external pressure, the air inside the sealed cavity is compressed. The force generated by the air compression needs to be balanced by the preload of the mounting screws. As the degree of air compression decreases, the preload gradually decreases, and the mounting screws may even come loose completely, losing all preload and ultimately causing the sealing ring to be damaged, resulting in serious consequences of seal failure. Summary of the Invention

[0005] The purpose of this invention is to overcome one of the shortcomings of the prior art and provide a radial sealing structure and installation method.

[0006] The technical solution of the present invention: a radial sealing structure installation method, which is achieved through the following steps:

[0007] Step 1: Preparations before sealing;

[0008] The second step is to align the sealing cap with the sealing ring with the sealing cylinder and place it inside the vacuum chamber.

[0009] The third step is to evacuate the vacuum chamber to a pressure below 0.1 atmospheres and maintain the pressure for more than 1 minute.

[0010] The fourth step is to inflate the vacuum chamber and install the sealing cover in place.

[0011] Fifth step: Install and tighten the connecting screws between the sealing cap and the sealing cylinder.

[0012] A radial sealing structure obtained by any of the installation methods described above.

[0013] The beneficial effects of this invention compared to the prior art are as follows:

[0014] (1) The present invention adopts a special assembly method, which can effectively reduce the assembly difficulty of the sealing structure, ensure that the sealing structure is assembled in place, and maintain the pre-tightening force of the assembly screws to prevent the sealing structure from failing due to the reduction of the pre-tightening force.

[0015] (2) The vacuuming process in the assembly process of the present invention removes the air in the sealing cavity (at this time, the sealing cover is only placed on the sealing cylinder and cannot prevent the air in the sealing cavity from flowing out). After the assembly is completed, the internal pressure of the sealing cavity will be slightly less than the atmospheric pressure outside the cavity, thereby solving the problem that the preload force gradually decreases over time in the prior art, which leads to thread preload failure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a common radial sealing structure;

[0017] Figure 2 This is a flowchart of the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific examples and accompanying drawings.

[0019] The present invention is as follows Figure 2 As shown, a method is provided as follows Figure 1 The installation method of the radial sealing structure shown is achieved through the following steps:

[0020] The first step is preparation before sealing.

[0021] This step includes, but is not limited to, the following:

[0022] (1) Inspect and clean the sealing surface. The sealing surface must be free of scratches, dirt or other defects that may affect the sealing effect.

[0023] (2) Inspect the sealing ring. The surface of the sealing ring must not have defects such as dirt, lumps, or damage, and the burrs on the parting surface must meet the design requirements.

[0024] (3) Place the sealing ring into the sealing groove. The sealing ring must not be flipped or twisted.

[0025] Other general requirements before sealing assembly.

[0026] The second step is to align the sealing cap with the sealing ring and the sealing cylinder and place it inside the vacuum chamber.

[0027] In this step, ensure that the sealing cap and the sealing cylinder are aligned, that is, the screw mounting holes on the sealing cap are aligned with the threaded holes on the sealing cylinder.

[0028] The third step is to evacuate and maintain pressure in the vacuum chamber.

[0029] In this step, the vacuum chamber is evacuated to below 0.1 atmospheres and held at that pressure for at least 1 minute to allow the air inside the sealed cavity to be fully expelled, achieving pressure balance between the inside and outside of the sealed cavity. Preferably, the vacuum chamber is evacuated to below 0.05 MPa (0.5 atmospheres) and held at that pressure for 3 to 5 minutes.

[0030] The fourth step is to inflate the vacuum chamber and install the sealing cover in place.

[0031] In this step, the air inlet valve of the vacuum chamber is opened to allow the vacuum chamber to be filled with air quickly. During the filling process, the sealing cover will be installed in place in one go under the action of air pressure.

[0032] Furthermore, if the sealing cap is not installed properly in this step, check the sealing ring and sealing surface, adjust them, and repeat steps two through four.

[0033] Furthermore, in this step, first check whether the sealing ring and sealing surface are incorrectly positioned or damaged. If such situations exist, adjust the sealing ring and sealing surface and repeat steps two to four until the sealing cover is installed in place.

[0034] Furthermore, if the above situation does not exist in this step, then by appropriately reducing the air pressure in the vacuum chamber or extending the pressure holding time, repeat steps two to four until the sealing cover is installed in place.

[0035] Fifth step: Install and tighten the connecting screws between the sealing cap and the sealing cylinder.

[0036] In this step, when tightening the connecting screws, they should be screwed in sequentially in either a clockwise or counterclockwise direction.

[0037] Furthermore, in this step, the connecting screws are tightened by multiple turns.

[0038] Preferably, this step is as follows:

[0039] A5.1 Tighten the first screw to eliminate any free travel of the connecting screw.

[0040] A5.2. Tighten the screws in the second round using 5-15% of the tightening torque, and tighten the connecting screws in sequence.

[0041] The tightening torque mentioned in this step refers to the tightening torque specified by the assembly process when assembling the screws. Different types, grades, and materials of screws can be referenced in relevant standards; the specific standard to be followed should be determined based on the actual situation.

[0042] A5.3. Increase the tightening torque by 15-30% each time until the connecting screw is fully tightened.

[0043] In the fifth step, the order of tightening the multiple wheels must be kept consistent.

[0044] The preferred screw tightening method in this step ensures more even force distribution on the sealing ring and facilitates better air pressure balance inside and outside the sealing cavity.

[0045] Furthermore, the present invention also includes the following steps:

[0046] Step 6: Loosen all the mounting screws of the sealing connector and check if air can smoothly enter the sealing cavity. If so, proceed to step 7.

[0047] In this step, during the process of loosening the mounting screws of the sealing connector, the sealing connector cannot be completely pulled out of the sealing connector mounting hole.

[0048] This step allows air to enter the sealed cavity, ensuring that the pressure inside and outside the sealed cavity is balanced after assembly.

[0049] Furthermore, if no air enters the sealed cavity during this step, or if the entry process is very violent, adjust the vacuum chamber parameters in step three and repeat steps four through six until air can enter the sealed cavity smoothly.

[0050] This step is to check the above assembly process. If no air enters the sealed cavity, or if the entry process is very violent (with a whistling sound), it means that the parameters of the vacuum chamber are not set properly during the assembly process and need to be adjusted.

[0051] Step 7: Tighten the mounting screws of the sealing connector to complete the entire assembly process.

[0052] Furthermore, the present invention also provides a radial sealing structure obtained by the above-described installation method.

[0053] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A method for installing a radial sealing structure, characterized in that, This can be achieved through the following steps: Step 1: Preparations before sealing; The second step is to align the sealing cap with the sealing ring with the sealing cylinder and place it inside the vacuum chamber. The third step is to evacuate the vacuum chamber to a pressure below 0.1 atmospheres and maintain the pressure for more than 1 minute. The fourth step is to inflate the vacuum chamber and install the sealing cover in place. Fifth step: Install and tighten the connecting screws between the sealing cap and the sealing cylinder; Step 6: Loosen all the mounting screws of the sealing connector and check if air can smoothly enter the sealing cavity. If so, proceed to step 7. Step 7: Tighten the mounting screws of the sealing connector.

2. The radial sealing structure installation method according to claim 1, characterized in that: In the fifth step, when tightening the connecting screws, screw them in one by one in a clockwise or counterclockwise direction.

3. The radial sealing structure installation method according to claim 2, characterized in that: In the fifth step, the connecting screws are tightened by multiple turns, and the order of the turns must be kept consistent.

4. The radial sealing structure installation method according to claim 3, characterized in that: The fifth step is as follows: A5.1 Tighten the first screw to eliminate any free travel of the connecting screw; A5.

2. Tighten the screws in the second round using 5-15% of the tightening torque, and tighten the connecting screws in sequence. A5.

3. Increase the tightening torque by 15-30% each time until the connecting screw is fully tightened.

5. The radial sealing structure installation method according to claim 1, characterized in that: In the sixth step, if no air enters the sealed cavity, or if the entry process is very violent, adjust the vacuum box parameters in the third step and repeat steps four through six until air can enter the sealed cavity smoothly.

6. The radial sealing structure installation method according to claim 1, characterized in that: If the sealing cap is not installed properly in the fourth step, check the sealing ring and sealing surface, adjust them, and then repeat steps two through four.

7. The radial sealing structure installation method according to claim 6, characterized in that: In the fourth step, first check whether the sealing ring and sealing surface are incorrectly positioned or damaged. If such a situation exists, adjust the sealing ring and sealing surface and repeat steps two to four until the sealing cover is installed in place. If such a situation does not exist, reduce the air pressure in the vacuum chamber or extend the pressure holding time, and then repeat steps two to four until the sealing cover is installed in place.

8. The radial sealing structure installation method according to claim 1, characterized in that: The first step includes inspecting and cleaning the sealing surface, inspecting the sealing ring, and placing the sealing ring into the sealing groove. In the second step, ensure that the sealing cap and the sealing cylinder are aligned, that is, the screw mounting holes on the sealing cap are aligned with the threaded holes on the sealing cylinder; In the third step, the vacuum chamber is evacuated to below 0.05 MPa and held at that pressure for 3 to 5 minutes; and / or In the sixth step, during the process of loosening the mounting screws of the sealing connector, the sealing connector cannot be completely pulled out of the sealing connector mounting hole.

9. A radial sealing structure obtained by the installation method according to any one of claims 1-8.

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