Mechanical seal device for a metal bellows

Abstract

The utility model discloses a kind of mechanical sealing devices of secret metal bellows, it is related to bellows mechanical sealing technical field, including bellows, one end of the bellows is connected with dynamic ring, another end of the bellows is connected with transmission seat, the bellows outside is equipped with protective sleeve, one end of the protective sleeve is fixedly connected with the transmission seat, another end of the protective sleeve is sealed sliding connection with the outer circumferential wall of dynamic ring by first auxiliary sealing element, and the dynamic ring is close to the bellows one end between the first auxiliary sealing element and is provided with reserved expansion gap;Transmission seat is close to the bellows one end between the protective sleeve and is provided with second auxiliary sealing element.The utility model can form dynamic sealing effect with protective sleeve, bellows and dynamic ring, neither affect the compensation function of bellows, can effectively form isolation between internal bellows and external medium, prolong the service life of bellows.

Description

Technical Field

[0001] This utility model relates to the field of bellows mechanical seal technology, and in particular to a mechanical seal device for a shield-type metal bellows. Background Technology

[0002] Mechanical seals are key components in rotating equipment for achieving static and dynamic sealing. They form a sealing surface through the mating of the end faces of a stationary ring and a rotating ring, and utilize the elastic compensation function of the bellows assembly to ensure that the sealing surface remains in contact, thereby preventing media leakage. In existing mechanical seal structures, the bellows (especially metal bellows) are usually directly exposed to the media environment to achieve axial expansion and contraction compensation.

[0003] However, in environments with particulate, high-viscosity, highly corrosive, or high-temperature and high-pressure media, bellows in direct contact with the media are prone to the following problems: (1) Solid particles in the media erode the surface of the bellows as the fluid flows, causing wear, thinning of the wall, and even cracks; (2) Corrosive media can chemically erode the bellows material, reducing its mechanical strength and sealing performance; (3) High-viscosity media can easily accumulate in the bellows gaps, hindering the normal expansion and contraction of the bellows and causing compensation failure. All of the above problems will shorten the service life of the mechanical seal, increase equipment maintenance costs, and even cause safety hazards.

[0004] Although existing technologies have attempted to protect bellows with sheaths, most sheaths are rigid structures that cannot expand and contract synchronously with the bellows. This results in gaps between the sheath and the bellows, allowing the medium to easily enter the inner side of the sheath and corrode the bellows. Alternatively, the rigid connection between the sheath and the bellows limits the bellows' compensation capacity and affects the sealing pressure. Therefore, there is an urgent need for a protective sealing device that can effectively isolate the medium from the bellows without affecting the bellows' compensation function. Utility Model Content

[0005] The purpose of this utility model is to provide a mechanical sealing device for a shield-type metal bellows, which solves the problem mentioned in the background art that although the prior art has also attempted to protect the bellows with a sheath, most of the sheaths are rigid structures that cannot expand and contract synchronously with the bellows, or the sheath is rigidly connected to the bellows, which limits the compensation amount of the bellows and affects the sealing surface contact pressure.

[0006] The present invention adopts the following technical solution:

[0007] This utility model discloses a mechanical sealing device for a shield-type metal bellows, comprising a bellows, one end of which is connected to a rotating ring, and the other end of which is connected to a transmission seat. A protective sleeve is fitted on the outside of the bellows, one end of which is fixedly connected to the transmission seat, and the other end of which is slidably connected to the outer peripheral wall of the rotating ring through a first auxiliary sealing element. A reserved expansion gap is provided between the end of the rotating ring near the bellows and the first auxiliary sealing element.

[0008] A second auxiliary seal is provided between the end of the transmission seat near the bellows and the protective sleeve.

[0009] Preferably, the length of the reserved expansion gap is 0.5 to 1.5 mm.

[0010] Preferably, the protective sleeve is provided with a first reserved threaded hole, and the transmission seat is provided with a second reserved threaded hole at the corresponding position of the first reserved threaded hole. The first reserved threaded hole and the second reserved threaded hole are connected by a set screw.

[0011] Preferably, the first auxiliary seal includes a first sealing ring groove and a first sealing ring. The first sealing ring groove is disposed on the inner peripheral wall of the protective sleeve, the first sealing ring is sealed in the first sealing ring groove, and the first sealing ring is slidably sealed on the outer peripheral wall of the moving ring.

[0012] Preferably, the second auxiliary seal includes a second sealing ring groove and a second sealing ring. The second sealing ring groove is disposed on the inner peripheral wall of the protective sleeve, the second sealing ring is sealed in the second sealing ring groove, and the second sealing ring is sealed on the outer peripheral wall of the transmission seat.

[0013] Preferably, the protective sleeve has an inner groove for avoiding obstruction between the first auxiliary seal and the second auxiliary seal, and the inner groove for avoiding obstruction is located on the outside of the bellows.

[0014] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0015] This utility model has a simple structure and low cost. It can form a dynamic sealing effect between the protective sleeve, the bellows, and the moving ring. It will not affect the compensation function of the bellows, and can effectively isolate the internal bellows from the external medium, avoiding the scouring and corrosion of the bellows by the medium, and significantly extending the service life of the bellows and the entire mechanical seal. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1Cross-sectional view of the mechanical sealing device of the shield-type metal bellows of this utility model. Figure 1 ;

[0018] Figure 2 Cross-sectional view of the mechanical sealing device of the shield-type metal bellows of this utility model. Figure 2 ;

[0019] Figure 3 This is a cross-sectional view of the protective sleeve in the mechanical sealing device of the shield-type metal bellows of this utility model.

[0020] Figure 4 This is a cross-sectional view of the moving ring in the mechanical sealing device of the shield-type metal bellows of this utility model.

[0021] Figure 5 This is a side view of the moving ring in the mechanical seal device of the shield-type metal bellows of this utility model.

[0022] Explanation of reference numerals in the attached drawings: 1. Moving ring; 2. Bellows; 3. Transmission seat; 3-1. Second reserved threaded hole; 4. Protective sleeve; 4-1. First reserved threaded hole; 4-2. Clearance groove; 5. Reserved expansion gap; 6. Second auxiliary seal; 6-1. Second sealing ring groove; 6-2. Second sealing ring; 7. First auxiliary seal; 7-1. First sealing ring groove; 7-2. First sealing ring; 8. Set screw. Detailed Implementation

[0023] To make the technical problems, technical solutions and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figures 1 to 3 As shown, this embodiment discloses a mechanical sealing device for a shield-type metal bellows, including a bellows 2. One end of the bellows 2 is connected to a rotating ring 1 by welding, and the other end of the bellows 2 is connected to a transmission seat 3 by welding. A protective sleeve 4 is fitted over the outside of the bellows 2. One end of the protective sleeve 4 is fixedly connected to the transmission seat 3, and the other end of the protective sleeve 4 is dynamically sealed to the outer peripheral wall of the rotating ring 1 through a first auxiliary seal 7. A reserved expansion gap 5 is provided between the end of the rotating ring 1 near the bellows 2 and the first auxiliary seal 7 to avoid friction between the protective sleeve 4 and the body of the bellows 2. A second auxiliary seal 6 is provided between the end of the transmission seat 3 near the bellows 2 and the protective sleeve 4.

[0025] The material of the protective cover 4 can be flexibly adjusted according to the characteristics of the medium (temperature, corrosiveness, particle content, etc.), and no limitation is made here.

[0026] In this embodiment, the first auxiliary seal 7 includes a first sealing ring groove 7-1 and a first sealing ring 7-2. The first sealing ring groove 7-1 is disposed on the inner peripheral wall of the protective sleeve 4, and the first sealing ring 7-2 is sealed within the first sealing ring groove 7-1, and the first sealing ring 7-2 is slidably sealed on the outer peripheral wall of the moving ring 1. The second auxiliary seal 6 includes a second sealing ring groove 6-1 and a second sealing ring 6-2. The second sealing ring groove 6-1 is disposed on the inner peripheral wall of the protective sleeve 4, and the second sealing ring 6-2 is sealed within the second sealing ring groove 6-1, and the second sealing ring 6-2 is sealed on the outer peripheral wall of the transmission seat 3. With the help of the design of the first sealing ring 7-2, the second sealing ring 6-2, and the reserved expansion gap 5, the bellows 2 can perform normal axial expansion and contraction, avoiding the protective sleeve 4 restricting the movement of the bellows 2, while simultaneously ensuring the sealing protection of the bellows 2 by the protective sleeve 4.

[0027] In this embodiment, the length of the reserved expansion gap 5 is 0.5 to 1.5 mm.

[0028] In this embodiment, the protective sleeve 4 is provided with an avoidance groove 4-2 between the first auxiliary seal 7 and the second auxiliary seal 6. The avoidance groove 4-2 is located on the outside of the bellows 2 to avoid interference with the normal expansion and contraction of the bellows 2 from the inside of the protective sleeve 4.

[0029] In this embodiment, the protective sleeve 4 is provided with a first reserved threaded hole 4-1, and the transmission seat 3 is provided with a second reserved threaded hole 3-1 at the corresponding position of the first reserved threaded hole 4-1. The first reserved threaded hole 4-1 and the second reserved threaded hole 3-1 are connected together by a set screw 8, thereby fixing the protective sleeve 4 to the transmission seat 3. It should be noted that in some embodiments, other fixing connection methods can also be used, such as the transmission seat 3 and the protective sleeve 4 using an interference fit seal, so that the protective sleeve 4 is tightly fitted onto the transmission seat 3.

[0030] The working principle of this utility model is as follows:

[0031] Because the protective sleeve 4 forms a dynamic seal with the rotating ring 1 through the first sealing ring groove 7-1 and the first sealing ring 7-2, when the bellows 2 expands and contracts axially and the rotating ring 1 moves axially, the rotating ring 1 and the protective sleeve 4 move relative to each other but can still maintain a sealed state. In this way, the protective sleeve 4 effectively isolates the internal bellows 2 from the external medium, avoiding the problems of scouring and corrosion by the medium, and at the same time, it does not affect the compensation function of the internal bellows 2.

[0032] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A mechanical seal device for a shield-type metal bellows, comprising a bellows (2), one end of which is connected to a moving ring (1), and the other end of which is connected to a transmission seat (3), characterized in that: The corrugated pipe (2) is fitted with a protective sleeve (4). One end of the protective sleeve (4) is fixedly connected to the transmission seat (3). The other end of the protective sleeve (4) is slidably connected to the outer peripheral wall of the moving ring (1) through the first auxiliary seal (7). A reserved expansion gap (5) is provided between the end of the moving ring (1) near the corrugated pipe (2) and the first auxiliary seal (7). A second auxiliary seal (6) is provided between the end of the transmission seat (3) near the bellows (2) and the protective sleeve (4).

2. The mechanical sealing device for a shield-type metal bellows according to claim 1, characterized in that: The length of the reserved expansion gap (5) is 0.5 to 1.5 mm.

3. The mechanical sealing device for a shield-type metal bellows according to claim 1, characterized in that: The protective sleeve (4) is provided with a first reserved threaded hole (4-1), and the transmission seat (3) is provided with a second reserved threaded hole (3-1) at the corresponding position of the first reserved threaded hole (4-1). The first reserved threaded hole (4-1) and the second reserved threaded hole (3-1) are connected by a set screw (8).

4. The mechanical seal device for a shield-type metal bellows according to claim 1, characterized in that: The first auxiliary seal (7) includes a first sealing ring groove (7-1) and a first sealing ring (7-2). The first sealing ring groove (7-1) is disposed on the inner peripheral wall of the protective sleeve (4). The first sealing ring (7-2) is sealed in the first sealing ring groove (7-1), and the first sealing ring (7-2) is slidably sealed on the outer peripheral wall of the moving ring (1).

5. The mechanical seal device for a shield-type metal bellows according to claim 1, characterized in that: The second auxiliary seal (6) includes a second sealing ring groove (6-1) and a second sealing ring (6-2). The second sealing ring groove (6-1) is disposed on the inner peripheral wall of the protective sleeve (4), and the second sealing ring (6-2) is sealed in the second sealing ring groove (6-1) and sealed on the outer peripheral wall of the transmission seat (3).

6. The mechanical seal device for a shield-type metal bellows according to claim 1, characterized in that: The protective sleeve (4) has an avoidance groove (4-2) between the first auxiliary seal (7) and the second auxiliary seal (6), and the avoidance groove (4-2) is located outside the bellows (2).

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