Sealing assembly capable of preventing axial extrusion and plunger pump

Abstract

The utility model relates to the technical field of sealing of a free gap between a cylinder and a plunger, and particularly discloses a sealing assembly capable of preventing axial extrusion, which comprises a mounting sleeve, an isolating ring and a sealing piece, at least two sealing grooves distributed in the axial direction are formed in the inner hole wall of the integral structure formed by the installation sleeve and the isolation ring, a sealing piece is installed in each sealing groove, and the adjacent sealing grooves are separated through the isolation ring. The plunger pump comprises a cylinder body and a plunger, and further comprises the sealing assembly which is fixedly installed on the cylinder body and used for preventing axial extrusion. The axial multi-sealing structure is used for solving the problem that a sealing assembly of an existing axial multi-sealing structure in high-pressure pumping equipment quickly loses efficacy.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing of the free clearance between a cylinder and a plunger, and particularly relates to a sealing assembly and a plunger pump for preventing axial extrusion. Background Art

[0002] In the pumping operation of high-viscosity fluids, plunger pumps are mostly used for pumping. When pumping materials, the plunger (the plunger is also called the "piston rod") needs to drive the piston to move up and down to realize the pumping of the fluid into the cylinder body or the extrusion of the fluid from the cylinder body. As the plunger, which is the driving rod of the plunger pump, needs to penetrate the cylinder body, in order to ensure that the reciprocating movement of the plunger will not cause fluid leakage, a sealing assembly needs to be fixedly installed at the end of the cylinder body, and the free clearance between the cylinder body and the plunger is sealed by the sealing assembly.

[0003] For the plunger pump used for pumping high-viscosity fluids, due to the high viscosity of the fluid, the pressure in the cylinder body is very high during pumping. If the sealing performance of the sealing assembly is not good, fluid leakage will occur. Currently, the most common way to improve the sealing performance is to arrange multiple seals axially in the sealing assembly to form axial multiple seals. For example, the "high-pressure plunger multiple-sealing structure of a plunger pump" with the patent publication number CN212429735U and the "high-pressure plunger multiple-sealing structure of a plunger pump" with the patent publication number CN217300872U. However, at present, when such a multiple-sealing assembly is used for pumping high-viscosity fluids with abrasives, there is a problem that the sealing assembly fails quickly. It will fail in as long as 20-odd days at the longest and in as short as 2 days at the shortest. For this reason, the inventor verified the existing multiple-sealing structure from various aspects such as the type and material of the seals and the movement control of the plunger, but still could not solve the problem of the rapid failure of the sealing assembly under high pressure in the cylinder body. Summary of the Utility Model

[0004] The utility model aims to provide a sealing assembly for preventing axial extrusion to solve the problem that the existing axial multiple-sealing structure has a rapid failure of the sealing assembly in high-pressure pumping equipment.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A sealing assembly for preventing axial extrusion includes a mounting sleeve, a spacer ring and seals. The spacer ring is fixedly arranged in the mounting sleeve, and at least two seal grooves distributed axially are arranged on the inner hole wall of the overall structure formed by the mounting sleeve and the spacer ring. Each seal groove is provided with a seal, and adjacent seal grooves are separated by the spacer ring.

[0007] R & D process of this solution: The rapid failure of the sealing component not only increases the consumable cost for the manufacturer on the one hand, but more importantly, the production line will stop due to the replacement of the sealing component, which greatly affects production. After the inventor's various attempts at design and experimental verification on the material change, structure change, and number of sealing layers change of the seal, the reason for the rapid failure of the existing multi-layer sealing component was finally discovered. The reason analysis is as follows: In the current multi-layer seal, although adjacent seals are separated by a support ring (also known as an isolation ring or a guide ring), all seals and support rings are installed in the same annular space; when the cylinder body is in a high-pressure state, the high-pressure fluid will give an axial extrusion force to the sealing component towards the outside of the cylinder body, and this extrusion force will be transmitted to the seals and support rings located in the same annular space. The support ring is made of a hard material, but the seal has elasticity, so that the seal bears the axial extrusion force for a long time. The seals farther away from the middle of the cylinder body are subjected to too much axial extrusion force, resulting in the failure of the seal originally acting as the last layer of seal prior to other seals, greatly reducing the sealing effect; after the failure of the last layer of seal, the axial space between the seal and the support ring in the annular space increases, and more fluid will squeeze into the sealing component, so that under the reciprocating movement of the plunger, the wear rate of the seal is increased, making it impossible to solve the problem of unsatisfactory sealing performance under multi-layer sealing no matter how high-quality seals are replaced and the stability / coaxiality of the plunger reciprocating movement is ensured.

[0008] In this solution, each seal is installed in its respective sealing groove, and adjacent sealing grooves are isolated by an isolation ring. When the isolation ring is fixedly installed relative to the mounting sleeve, the isolation grooves do not affect each other, avoiding the situation where there is an axial extrusion force between adjacent seals under fluid pressure, so as to ensure that each seal can play the maximum sealing role, ensuring that the axial multi-layer seal can truly play its role, improving the sealing performance and extending the service life of the sealing component. It has been verified that under the same working conditions, the life of the sealing component before improvement needs to be replaced after only about 20 days, while under the design of this solution, the life of the sealing component is extended to 4 months and is still in an effective use state, greatly improving the durability of the sealing component.

[0009] Preferably, as an improvement, the mounting sleeve is provided with a mounting groove, the isolation ring is installed in the mounting groove, and a tightening block is arranged at the notch of the mounting groove, and the tightening block is used to tighten the isolation ring in the mounting groove.

[0010] Beneficial effects: The structure of this solution is simple, and the seal and the isolation ring are both located on the mounting sleeve, which is convenient for the disassembly and assembly of the sealing component.

[0011] Preferably, as an improvement, the isolation ring includes an annular protrusion and an abutting cylinder fixedly connected to the annular protrusion and perpendicular to the annular protrusion. A sealing groove is formed by enclosing between the annular protrusion and the abutting cylinder. Adjacent sealing grooves are separated by the annular protrusion, and the abutting cylinder is used to abut against the installation sleeve.

[0012] Beneficial effects: When adopting this solution, the self-construction design of the isolation ring takes into account the formation of the sealing groove and the relative fixation of the isolation ring in the installation sleeve.

[0013] Preferably, as an improvement, the installation sleeve is provided with a stepped groove with steps. The smallest-sized step of the stepped groove forms a sealing groove for installing the sealing member, and the remaining steps of the stepped groove form the installation groove, so that the formation of one of the sealing grooves is facilitated through the design of the stepped groove and the installation of the isolation ring is facilitated.

[0014] Preferably, as an improvement, a guiding ring coaxial with the plunger is installed on the installation sleeve. The axial movement stability of the plunger is improved through the guiding ring, thereby improving the concentricity of the plunger pump, reducing the wear between the sealing member and the plunger, and avoiding the phenomenon of eccentric wear.

[0015] Preferably, as an improvement, the guiding ring is located at one end away from the cylinder block.

[0016] Beneficial effects: Since the other end of the plunger is in the cylinder block and there is a piston in the cylinder block, the farther the guiding ring is from the cylinder block, the farther the distance between the guiding ring and the piston to the component with a guiding function formed by the plunger, which helps to further improve the axial movement stability of the plunger.

[0017] Preferably, as an improvement, an oil groove is provided on the installation sleeve. The oil groove surrounds the outer circumference of the plunger. The installation sleeve, the isolation ring and the plunger are all in clearance fit, so as to facilitate injecting lubricating oil into the oil groove, and the lubricating oil flows into the gap between the sealing member and the plunger along the gap between the installation sleeve, the isolation ring and the plunger, thereby realizing lubrication.

[0018] Preferably, as an improvement, the oil groove is located at the top of the installation sleeve, and multiple sealing members are all located below the oil groove, so that the lubricating oil in the oil groove can penetrate downward to the sealing members under its own weight, further improving the lubrication effect.

[0019] Preferably, as an improvement, the sealing member is a lip seal.

[0020] The present utility model also provides a plunger pump, which includes a cylinder block and a plunger, and further includes the above-mentioned anti-axial extrusion sealing assembly fixedly installed on the cylinder block.

[0021] Preferably, as an improvement, the installation sleeve is inserted into the cylinder block, and a sealing ring is arranged between the outer circumference of the installation sleeve and the inner wall of the cylinder block.

[0022] Beneficial effects: Compared with the way of butt-joint between the sealing component and the cylinder block at the end face, in this solution, the installation sleeve is installed in the cylinder block to improve the sealing effect of the sealing component at the end of the cylinder block, while ensuring the simplicity of disassembly of the sealing component. The setting of the sealing ring further improves the sealing effect of the sealing component. Brief description of the drawings

[0023] Figure 1 The main view cross-sectional view of the first embodiment of the present utility model (the sealing component in the figure is shown in cooperation with the plunger and the cylinder block).

[0024] Figure 2 is Figure 1 the three-dimensional structure schematic diagram of the isolation ring in Figure 1 , this Figure 2 shows the isolation ring with the sealing groove facing upwards to display the structure of the isolation ring.

[0025] Figure 3 The main view cross-sectional view of the second embodiment of the present utility model.

[0026] Figure 4 The main view cross-sectional view of the third embodiment of the present utility model.

[0027] Figure 5 The main view cross-sectional view of the fourth embodiment of the present utility model. Specific implementation manners

[0028] The following is a further detailed description through specific implementation manners:

[0029] The reference numerals in the drawings of the specification include: installation sleeve 1, oil groove 11, isolation ring 2, annular protrusion 21, abutting cylinder 22, sealing member 3, abutting block 4, guiding ring 5, cylinder block 10, plunger 20.

[0030] Embodiment 1

[0031] Combined with Figure 1 and Figure 2 , a sealing component for preventing axial extrusion includes an installation sleeve 1, an isolation ring 2 and a sealing member 3. A stepped groove with two levels of steps is machined on the installation sleeve 1. The small-sized step of the stepped groove forms a sealing groove for installing the sealing member 3, and the large-sized step of the stepped groove forms an installation groove for installing the isolation ring 2.

[0032] The isolation ring 2 includes an integrally formed annular protrusion 21 and an abutting cylinder 22. The annular protrusion 21 is perpendicular to the abutting cylinder 22, the abutting cylinder 22 is parallel to the plunger 20. A sealing groove for installing the sealing member 3 is formed by enclosing between the annular protrusion 21 and the abutting cylinder 22. Adjacent sealing grooves are separated by the annular protrusion 21, and the abutting cylinder 22 is used to abut inside the installation sleeve 1.

[0033] A pressing block 4 is placed on the opening of the installation groove of the installation sleeve 1. The pressing block 4 is used to press the isolation ring 2 tightly in the installation groove. In this embodiment, the pressing block 4, the isolation ring 2, and the installation sleeve 1 are all made of metal, and the pressing block 4 is a metal gasket ring.

[0034] In this embodiment, the installation sleeve 1 is detachably connected to the cylinder block 10. One end face of the pressing block 4 presses against the installation sleeve 1 and the isolation ring 2, and the other end face of the pressing block 4 presses against the cylinder block 10.

[0035] In this embodiment, the number of isolation rings 2 is one. The sealing grooves on the isolation ring 2 and the sealing grooves on the installation sleeve 1 are arranged along the axial direction of the plunger 20, so as to facilitate the installation of 2 axially distributed sealing elements 3 on the sealing assembly. In this embodiment, the sealing element 3 is a pantograph seal.

[0036] To improve the stability of the movement of the plunger 20, a guiding groove is formed on the installation sleeve 1, and a wear-resistant guiding ring 5 is installed in the guiding groove. The guiding ring 5 is located at the end far from the cylinder block 10, and the guiding ring 5 is coaxial with the plunger 20. In this embodiment, the guiding ring 5 is a Sly ring. The guiding ring 5 in this embodiment can improve the concentricity of the plunger pump, thereby reducing the wear between the sealing element 3 and the plunger 20 and avoiding the phenomenon of eccentric wear.

[0037] To achieve the lubrication of the sealing assembly, an oil groove 11 is machined on the top of the installation sleeve 1 (the oil groove 11 is arranged on the installation sleeve 1 to form an oil cup structure). The oil groove 11 surrounds the outer circumference of the plunger 20. The installation sleeve 1 and the isolation ring 2 are both in clearance fit with the plunger 20, and all the sealing elements 3 are located below the oil groove 11, so that the lubricating oil in the oil groove 11 can penetrate downward to the sealing elements 3 under its own weight, improving the lubrication effect.

[0038] In this embodiment, each sealing element 3 is installed in its respective sealing groove, and adjacent sealing grooves are isolated by the isolation ring 2. When the isolation ring 2 is fixedly installed relative to the installation sleeve 1, the isolation grooves do not affect each other, avoiding the situation where there is an axial extrusion force between adjacent sealing elements 3 under the fluid pressure, so as to ensure that each sealing element 3 can play the maximum sealing role, ensuring that the axial multi-sealing can truly play its role, improving the sealing performance and extending the service life of the sealing assembly. It has been verified that under the same working conditions, the life of the sealing assembly before improvement needs to be replaced after only about 20 days, while in the design of this solution, the life of the sealing assembly is extended to 4 months and is still in an effective use state, greatly improving the durability of the sealing assembly.

[0039] Embodiment Two

[0040] Combined with Figure 3 , the difference between Embodiment Two and Embodiment One is that: in this embodiment, the number of isolation rings 2 is two, so that the number of sealing grooves is 3, and the corresponding number of sealing elements 3 can also be installed 3.

[0041] Compared with the first embodiment, this embodiment has an additional axial seal, further improving the sealing performance.

[0042] The third embodiment

[0043] Combined with Figure 4 , the difference between the third embodiment and the first embodiment is that there is only an installation groove for installing the isolation ring 2 in the installation sleeve 1, rather than a stepped groove. The number of isolation rings 2 is increased by 1, and all the sealing grooves of the sealing assembly are formed by the structures on the isolation ring 2. Compared with the first embodiment, the dual sealing function of two seals 3 is also achieved.

[0044] The fourth embodiment

[0045] Combined with Figure 5 , a plunger 20 pump includes a cylinder block 10, a plunger 20, and a sealing assembly of any one of the first / second / third embodiments. The sealing assembly installed in this embodiment Figure 5 is the sealing assembly in the first embodiment, wherein the installation sleeve 1 of the sealing assembly is threadedly connected in the cylinder block 10, and an O-ring is provided between the outer periphery of the installation sleeve 1 and the inner wall of the cylinder block 10 to further improve the sealing effect of the sealing assembly.

[0046] The plunger 20 is sleeved in the hollow space of the sealing assembly, and the free gap between the cylinder block 10 and the plunger 20 is sealed by the sealing assembly.

[0047] Applying the sealing assembly to the plunger 20 pump in this embodiment greatly improves the sealing performance of the plunger 20 pump, and the service life of the sealing assembly is greatly extended compared with the prior art, greatly reducing the part replacement cost of the plunger 20 pump and helping to ensure the production efficiency.

[0048] The above are only the embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics known in the solutions are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solutions of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners in the specification can be used to explain the content of the claims.

Claims

1. A sealing assembly for preventing axial extrusion, comprising a mounting sleeve, a spacer ring and a sealing member, characterized in that: The isolating ring is fixedly arranged in the mounting sleeve. The mounting sleeve and the isolating ring form an integral structure with at least two sealing grooves distributed along the axial direction on the inner hole wall. A sealing element is installed in each sealing groove, and adjacent sealing grooves are separated by the isolating ring.

2. The sealing assembly for preventing axial extrusion according to claim 1, characterized in that: The mounting sleeve is provided with a mounting groove, the isolating ring is installed in the mounting groove, and a tightening block is provided on the notch of the mounting groove, and the tightening block is used to tighten the isolating ring in the mounting groove.

3. The sealing assembly for preventing axial extrusion according to claim 1, characterized in that: The isolation ring includes an annular protrusion, an abutment tube fixedly connected to the annular protrusion and perpendicular to the annular protrusion, the annular protrusion and the abutment tube enclose the sealing groove, adjacent sealing grooves are separated by the annular protrusion, and the abutment tube is used to abut against the installation sleeve.

4. The sealing assembly for preventing axial extrusion according to claim 2, characterized in that: The installation sleeve is provided with a stepped groove with steps, the minimum step of the stepped groove forms a sealing groove for installing the sealing member, and the remaining steps of the stepped groove form the installation groove.

5. The sealing assembly for preventing axial extrusion according to claim 1, characterized in that: A guide ring coaxial with the plunger is installed on the installation sleeve.

6. The sealing assembly for preventing axial extrusion according to claim 1, characterized in that: The mounting sleeve is provided with an oil groove which surrounds the outer periphery of the plunger. The mounting sleeve and the isolating ring are all clearance-matched with the plunger.

7. The sealing assembly for preventing axial extrusion according to claim 6, characterized in that: The oil groove is located at the top of the mounting sleeve, and a plurality of sealing elements are located below the oil groove.

8. The sealing assembly for preventing axial extrusion according to claim 1, characterized in that: The sealing element is a pan seal.

9. A plunger pump, comprising a cylinder body and a plunger, characterized in that: It also includes an anti-axial extrusion sealing assembly as described in any one of claims 1 to 8, which is fixedly mounted on the cylinder body.

10. A plunger pump according to claim 9, characterized in that: The installation sleeve is inserted into the cylinder body, and a sealing ring is arranged between the outer periphery of the installation sleeve and the inner wall of the cylinder body.

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