Combined packing structure and manufacturing method thereof

Abstract

The invention discloses a combined packing structure and a manufacturing method thereof, and relates to the technical field of sealing structures, the combined packing structure comprises a flexible pressing sleeve, a wear-resistant packing and a compensation packing, the flexible pressing sleeve is located on the outer side of the wear-resistant packing and the outer side of the compensation packing, a flexible cavity is formed in the flexible pressing sleeve, and the wear-resistant packing is arranged in the flexible cavity. The flexible cavity is used for being filled with an elastic medium. According to the combined packing structure and the manufacturing method thereof, eccentric wear can be prevented, and the maintenance period can be prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of sealing structures, and in particular to a combined packing structure and a manufacturing method thereof. Background Art

[0002] Dynamic seals can be divided into two basic forms: rotary seals and reciprocating seals. In oilfield production wellheads, there is a rod lifting process. Common lifting mechanisms include rotary type, such as ground screw pumps, and the seal between the wellhead and the sucker rod is a rotary seal; there are also reciprocating types, such as beam pumping units, and the seal between the wellhead and the sucker rod is a reciprocating seal.

[0003] In the above dynamic seal structure, sealing packing is often used to improve the sealing performance. The existing sealing packing has eccentric wear during use, which accelerates the failure of the seal, shortens the maintenance cycle, and requires frequent production stoppages to replace the packing. Summary of the invention

[0004] The purpose of the present invention is to provide a combined packing structure and a manufacturing method thereof, so as to solve the problems existing in the above-mentioned prior art, prevent eccentric wear and extend the maintenance cycle.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a combined packing structure, comprising: a flexible compression sleeve, a wear-resistant packing and a compensating packing, wherein the flexible compression sleeve is located outside the wear-resistant packing and the compensating packing, and a flexible cavity is arranged inside the flexible compression sleeve, and the flexible cavity is used to fill an elastic medium.

[0007] Preferably, the flexible compression sleeve is made of elastic material, the flexible compression sleeve is provided with an opening, the flexible compression sleeve is provided with a communication nozzle, and the communication nozzle can be communicated with the flexible cavity.

[0008] Preferably, the elastic medium is gas, liquid or a gas-liquid mixture.

[0009] Preferably, the compensating packing is spiral, and comprises a plurality of first packing bodies. A reinforcing structure is arranged between adjacent first packing bodies, and the inner diameter of the reinforcing structure is equal to the inner diameter of the first packing body, and the outer diameter of the reinforcing structure is smaller than the outer diameter of the first packing body.

[0010] Preferably, the reinforcement structure is an annular cloth sheet, and a plurality of through holes are opened on the reinforcement structure along the circumference of the reinforcement structure.

[0011] Preferably, the wear-resistant packing and the compensating packing have the same structure.

[0012] Preferably, the outer contour of the compensating packing includes a straight section, a primary cone section and a secondary cone section which are arranged in sequence.

[0013] Preferably, the wear-resistant packing is a spiral packing.

[0014] Preferably, the wear-resistant packing comprises a plurality of second packing root bodies, each of which is provided with an opening, and the opening of each of which is staggered.

[0015] The present invention provides a method for manufacturing the combined packing structure, comprising the following steps:

[0016] The production process of compensating packing includes:

[0017] Step 1: preparing a plurality of annular first base plates and a plurality of annular reinforcement structures, and opening a plurality of through holes on the reinforcement structures;

[0018] Step 2: placing a reinforcement structure between two adjacent first base bodies, and loading a plurality of first base bodies and a plurality of reinforcement structures into a mold cavity, pressing and vulcanizing them;

[0019] Step 3, spirally cutting the structure formed in step 2 to form a compensating packing;

[0020] The production process of wear-resistant packing includes:

[0021] The first method is to spirally cut the rubber tubular structure to form a spiral packing;

[0022] The second method is to cut openings on the sides of a plurality of second plate base bodies, stack the second plate base bodies together, and stagger the openings of the second plate base bodies;

[0023] The third method is to make wear-resistant packing according to the manufacturing process of compensating packing;

[0024] The flexible compression sleeve is arranged on the outside of the wear-resistant packing and the compensation packing, so that the side of the wear-resistant packing close to the compensation packing and the side of the compensation packing close to the wear-resistant packing are both located on the inside of the flexible compression sleeve.

[0025] Compared with the prior art, the present invention has achieved the following technical effects:

[0026] When the moving shaft is eccentric, the combined packing structure of the present invention can adjust its position accordingly to prevent eccentric wear and extend the maintenance period; while ensuring the sealing effect, the friction between the moving shaft and the combined packing structure can be reduced, thereby reducing the wear on the combined packing structure; when the packing is replaced, the combined packing structure of the present invention can discharge the excess gas, liquid or gas-liquid mixture in the flexible cavity of the flexible compression sleeve, thereby facilitating the removal of the old packing and the addition of the new packing; split replacement can be achieved, and the replacement process does not require the use of tools such as screwdrivers, thereby avoiding the problem of packing fragments caused by the use of screwdrivers, etc., and facilitating maintenance operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a cross-sectional view of the combined packing structure of the present invention;

[0029] Figure 2 It is an axonometric view of the flexible compression sleeve of the present invention;

[0030] Figure 3 is a cross-sectional view of the flexible compression sleeve of the present invention;

[0031] Figure 4 is a cross-sectional view of the wear-resistant packing of the present invention;

[0032] Figure 5 It is a cross-sectional view of the compensating packing of the present invention;

[0033] Figure 6 It is a schematic diagram of the first packing body and the reinforcement structure of the compensating packing of the present invention being stacked;

[0034] Figure 7 It is a schematic diagram of the enhanced structure of the present invention;

[0035] Figure 8 It is a schematic diagram of the vulcanization of the first packing body and the reinforcement structure of the compensating packing of the present invention;

[0036] Fig. 9 It is a schematic diagram of spiral cutting of the first base body and the reinforcement structure after vulcanization of the present invention;

[0037] In the figure: 1-flexible compression sleeve, 2-wear-resistant packing, 3-compensating packing, 4-flexible cavity, 5-connecting nozzle, 6-first packing body, 7-reinforcement structure, 8-through hole, 9-straight section, 10-first cone section, 11-second cone section, 12-second packing body. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide a combined packing structure and a manufacturing method thereof, so as to solve the problems existing in the above-mentioned prior art, prevent eccentric wear and extend the maintenance cycle.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Embodiment 1

[0042] like Figures 1 to 9 As shown, this embodiment provides a combined packing structure, including: a flexible compression sleeve 1, a wear-resistant packing 2 and a compensating packing 3. The flexible compression sleeve 1 is located outside the wear-resistant packing 2 and the compensating packing 3. A flexible cavity 4 is provided in the flexible compression sleeve 1. The flexible cavity 4 is used to fill an elastic medium. This embodiment controls the pressure of the elastic medium in the flexible cavity 4, adjusts the force of the side wall of the flexible cavity 4 close to the moving shaft to the axial direction, and continuously provides an extrusion force in the axial direction, so that the wear-resistant packing 2 and the compensating packing 3 are pressed against the moving shaft with appropriate force, thereby playing a sealing role.

[0043] In this embodiment, the flexible compression sleeve 1 is made of elastic material, the wall thickness of the flexible compression sleeve 1 is 4-6mm, the working air pressure is 0.6MPa, the limit air pressure is 1.2MPa, the flexible compression sleeve 1 is provided with an opening, the angle between the opening and the axis of the flexible compression sleeve 1 is 45°, and the flexible compression sleeve 1 is provided with a connecting nozzle 5, which can be connected to the flexible cavity 4, and the elastic medium is filled into the flexible cavity 4 through the connecting nozzle 5. The elastic medium is gas, liquid or gas-liquid mixture, for example, the elastic medium can be air, nitrogen, or oil-gas mixture. Different media are added to the flexible cavity 4 to play different roles. For example, when half nitrogen and half engine oil are added, the engine oil can absorb the heat of steam when steam is injected into the heavy oil well. When the oil is pumped, the wellhead temperature gradually decreases, and the engine oil continues to dissipate heat. In winter, because a high temperature can be maintained continuously, the elasticity of the flexible cavity 4 can be improved; in a water-bearing well, it can also prevent the surface of the moving shaft from freezing and scratching the combined packing structure.

[0044] In this embodiment, the compensating packing 3 is spiral-shaped, and the compensating packing 3 includes a plurality of first packing bodies 6, and the first packing bodies 6 are made of rubber. A reinforcing structure 7 is arranged between adjacent first packing bodies 6. The reinforcing structure 7 is preferably an annular cloth sheet, and can also be an annular structure made of other reinforcing materials. The tensile strength, wear resistance and durability of the cloth sheet material are better than those of the rubber material, which can increase the overall strength of the compensating packing 3, improve the stress conditions, and extend the service life. At the same time, during the disassembly process, the compensating packing 3 is not easy to be broken, which reduces the labor intensity; the reinforcing structure 7 is provided on the reinforcing structure A plurality of through holes 8 are provided in the circumference of 7. The inner diameter of the reinforcing structure 7 is equal to the inner diameter of the first packing body 6. The inner wall of the reinforcing structure 7 contacts the light rod and directly bears the friction force, which protects the first packing body 6 made of rubber. At the same time, the service life of the packing in the eccentric wear well can be extended. The outer diameter of the reinforcing structure 7 is smaller than the outer diameter of the first packing body 6, preferably 10-15mm smaller. Since the outer diameter of the reinforcing structure 7 is smaller than the outer diameter of the first packing body 6, the contact surface between the compensating packing 3 and the inner wall of the packing cavity of the packing box still belongs to the rubber seal, giving full play to the excellent sealing property of the rubber. The reinforcing structure 7 has multiple through holes 8 evenly distributed along the circumference. At the same time, the outer diameter of the reinforcing structure 7 is smaller than the outer diameter of the first packing body 6, which can ensure the connection effect of the first packing body 6 made of multi-layer rubber material and the multi-layer reinforcing structure 7 during the pressing and vulcanization process.

[0045] In this embodiment, the outer contour of the compensating packing 3 includes a straight section 9, a primary cone section 10 and a secondary cone section 11 arranged in sequence, and the primary cone section 10 and the secondary cone section 11 cooperate with the steel parts in the packing box. Under the action of the two-stage conical chamfer, the relative movement of the moving shaft can be coordinated, and the moving shaft can be continuously held along the cone, thereby extending the overall sealing cycle and reducing the labor intensity of replacing the packing.

[0046] In this embodiment, the structure of the wear-resistant packing 2 has three forms: the first form, the wear-resistant packing 2 is a spiral packing; the second form, the wear-resistant packing 2 includes a plurality of second packing bodies 12, for example, 2-4 pieces, the second packing bodies 12 are made of rubber, each second packing body 12 is provided with an opening, and the openings of each second packing body 12 are staggered; the third form, the wear-resistant packing 2 and the compensating packing 3 have the same structure;

[0047] This embodiment can reduce the friction between the moving shaft and the combined packing structure while ensuring the sealing effect, thereby reducing the wear on the combined packing structure; when the moving shaft is eccentric, the combined packing structure can adjust its position accordingly to prevent eccentric wear and extend the maintenance cycle; when the combined packing structure of this embodiment is replaced with the packing, the excess gas, liquid or gas-liquid mixture in the flexible cavity 4 of the flexible compression sleeve 1 is discharged, so that the old packing is easily taken out and the new packing is added; split replacement can be achieved, and the replacement process does not require the use of tools such as screwdrivers, thereby avoiding the problem of packing fragments caused by the use of screwdrivers, etc., and facilitating maintenance operations.

[0048] Embodiment 2

[0049] like Figures 1 to 9 As shown, this embodiment provides a method for manufacturing a combined packing structure of embodiment 1, comprising the following steps:

[0050] The manufacturing process of compensating packing 3 includes:

[0051] Step 1: prepare a plurality of annular first base plates 6 and a plurality of annular reinforcement structures 7, and open a plurality of through holes 8 on the reinforcement structures 7;

[0052] Step 2: placing a reinforcement structure 7 between two adjacent first base bodies 6, and loading a plurality of first base bodies 6 and a plurality of reinforcement structures 7 into the mold cavity, and pressing and vulcanizing them under high temperature and high pressure;

[0053] Step 3, spirally cutting the structure formed in step 2 to form a compensating packing 3;

[0054] The production process of wear-resistant packing 2 includes the following methods:

[0055] The first method is to spirally cut the rubber tubular structure to form a spiral packing;

[0056] The second method is to cut openings on the sides of a plurality of second plate base bodies 12, and stack the second plate base bodies 12 together, with the openings of the second plate base bodies 12 being staggered;

[0057] The third method is to manufacture the wear-resistant packing 2 according to the manufacturing process of the compensating packing 3;

[0058] The flexible compression sleeve 1 is sleeved on the outside of the wear-resistant packing 2 and the compensation packing 3 so that the side of the wear-resistant packing 2 close to the compensation packing 3 and the side of the compensation packing 3 close to the wear-resistant packing 2 are both located on the inner side of the flexible compression sleeve 1.

[0059] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A combined packing structure, characterized in that: include: A flexible compression sleeve, a wear-resistant packing and a compensating packing, wherein the flexible compression sleeve is located outside the wear-resistant packing and the compensating packing, and a flexible cavity is arranged inside the flexible compression sleeve, and the flexible cavity is used to fill an elastic medium.

2. The combined packing structure according to claim 1, characterized in that: The flexible compression sleeve is made of elastic material, is provided with an opening, and is provided with a communication nozzle, and the communication nozzle can be communicated with the flexible cavity.

3. The combined packing structure according to claim 1, characterized in that: The elastic medium is gas, liquid or a gas-liquid mixture.

4. The combined packing structure according to claim 1, characterized in that: The compensating packing is spiral-shaped and includes a plurality of first packing bodies. A reinforcing structure is arranged between adjacent first packing bodies. The inner diameter of the reinforcing structure is equal to the inner diameter of the first packing body, and the outer diameter of the reinforcing structure is smaller than the outer diameter of the first packing body.

5. The combined packing structure according to claim 4, characterized in that: The reinforcement structure is an annular cloth sheet, and a plurality of through holes are opened on the reinforcement structure along the circumference of the reinforcement structure.

6. The combined packing structure according to claim 4, characterized in that: The wear-resistant packing and the compensating packing have the same structure.

7. The combined packing structure according to claim 1, characterized in that: The outer contour of the compensating packing includes a straight section, a primary cone section and a secondary cone section which are arranged in sequence.

8. The combined packing structure according to claim 1, characterized in that: The wear-resistant packing is a spiral packing.

9. The combined packing structure according to claim 1, characterized in that: The wear-resistant packing comprises a plurality of second packing root bodies, each of which is provided with an opening, and the opening of each of the second packing root bodies is staggered.

10. A method for manufacturing a combined packing structure according to any one of claims 1 to 9, characterized in that: The following steps are involved: The production process of compensating packing includes: Step 1: preparing a plurality of annular first base plates and a plurality of annular reinforcement structures, and opening a plurality of through holes on the reinforcement structures; Step 2: placing a reinforcement structure between two adjacent first base bodies, and loading a plurality of first base bodies and a plurality of reinforcement structures into a mold cavity, pressing and vulcanizing them; Step 3, spirally cutting the structure formed in step 2 to form a compensating packing; The production process of wear-resistant packing includes: The first method is to spirally cut the rubber tubular structure to form a spiral packing; The second method is to cut openings on the sides of a plurality of second plate base bodies, stack the second plate base bodies together, and stagger the openings of the second plate base bodies; The third method is to make wear-resistant packing according to the manufacturing process of compensating packing; The flexible compression sleeve is arranged on the outside of the wear-resistant packing and the compensation packing, so that the side of the wear-resistant packing close to the compensation packing and the side of the compensation packing close to the wear-resistant packing are both located on the inside of the flexible compression sleeve.

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