A high-pressure sealed plunger pump

Abstract

The present invention discloses a high-pressure sealed plunger pump, which comprises a pump body. A plunger cavity is provided inside the pump body, and a plunger rod is arranged inside the plunger cavity. The pump body is provided with a liquid inlet and a liquid outlet that communicate with the plunger cavity. A spring seal is provided at the front end of the plunger rod, and a spring seal ring is sleeved on the plunger rod. The sealing surfaces of the spring seal and the spring seal ring are arranged opposite to each other to form a sealing cavity, and a sealing liquid is injected into the sealing cavity. The pressure in the sealing cavity is greater than the pressure in the plunger cavity when transporting the liquid. The high-pressure sealed plunger pump of the present invention forms a sealing cavity by arranging the sealing surfaces of the spring seal and the spring seal ring opposite to each other, and injecting a sealing liquid into the sealing cavity, so that the pressure in the sealing cavity is greater than the pressure in the plunger cavity when transporting the liquid, playing a role in high-pressure sealing of the plunger cavity. Secondly, the sealing surface (i.e., the spring surface) of the spring seal ring faces the rear end, avoiding dead corners. During liquid replacement, it can be completely cleaned to avoid cross-contamination.

Description

Technical Field

[0001] The present invention relates to the technical field of plunger pumps, and particularly to a high-pressure sealed plunger pump. Background Art

[0002] When transporting liquids, plunger infusion pumps or diaphragm pumps are often used. The advantage of a plunger pump is that it can provide high-pressure liquid transportation, with high precision in the flow rate of the transported liquid and good linearity. The disadvantage is that a sealing ring with a spring is used inside the pump cavity, but the spring surface (i.e., the sealing surface) generally faces the liquid being transported, resulting in dead corners. When replacing the liquid, it cannot be completely cleaned, leading to cross-contamination. A diaphragm pump has no dead volume and is convenient for cleaning, but it cannot transport high-pressure liquids (the liquid pressure transported by diaphragm pumps on the market is generally not greater than 7 Bar (7 kilograms)), and the accuracy and flow rate linearity of the transported liquid are relatively poor at low flow rates. In the pharmaceutical field, hygienic requirements are often needed. The infusion pump needs to avoid dead corners to prevent cross-contamination, but it also needs to be able to provide an infusion pump with high-precision flow rate and high pressure resistance. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a high-pressure sealed plunger pump with a reasonable structure and avoiding dead corners. It adopts the following technical solutions:

[0004] A high-pressure sealed plunger pump, comprising:

[0005] A pump body, a plunger cavity is provided inside the pump body, a plunger rod is provided inside the plunger cavity, a liquid inlet and a liquid outlet communicating with the plunger cavity are provided on the pump body, a spring seal is provided at the front end of the plunger rod, a spring sealing ring is sleeved on the plunger rod, the sealing surfaces of the spring seal and the spring sealing ring are arranged opposite to each other to form a sealing cavity, a sealing liquid is injected into the sealing cavity, and the pressure in the sealing cavity is greater than the pressure in the plunger cavity when transporting the liquid.

[0006] As a further improvement of the present invention, an adjusting ring is sleeved on the plunger rod, and the adjusting ring abuts against the spring sealing ring to adjust the pressure in the sealing cavity.

[0007] As a further improvement of the present invention, an external thread is provided on the plunger rod, an internal thread matching the external thread is provided on the adjusting ring, and the adjusting ring is threadedly connected to the plunger rod.

[0008] As a further improvement of the present invention, the front end of the spring seal is a plane that cooperates with the bottom of the plunger cavity.

[0009] As a further improvement of the present invention, the sealing cavity is annular.

[0010] As a further improvement of the present invention, the front end of the plunger rod is threadedly connected to the spring seal.

[0011] As a further improvement of the present invention, the spring seal is provided with a threaded groove or a groove, and the front end of the plunger rod is provided with an external thread that cooperates with the threaded groove or the groove.

[0012] As a further improvement of the present invention, the front end of the plunger rod is connected to the spring seal by nesting.

[0013] As a further improvement of the present invention, the sealing liquid includes water and isopropyl alcohol.

[0014] As a further improvement of the present invention, the liquid inlet is provided with a liquid inlet check valve, and the liquid outlet is provided with a liquid outlet check valve.

[0015] Advantages of the present invention:

[0016] The high-pressure sealing plunger pump of the present invention has a reasonable structure. By setting a spring seal and a spring seal ring, and arranging the sealing surfaces of the spring seal and the spring seal ring opposite to each other to form a sealing cavity, and injecting a sealing liquid into the sealing cavity, the pressure in the sealing cavity is made greater than the pressure in the plunger cavity when transporting the liquid, thus playing a role in high-pressure sealing of the plunger cavity.

[0017] Secondly, the sealing surface of the spring seal ring (i.e., the spring surface) faces the rear end, avoiding dead corners. When replacing the liquid, it can be completely cleaned, avoiding cross-contamination.

[0018] The above description is only an overview of the technical solution of the present invention. In order to be able to more clearly understand the technical means of the present invention, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the high-pressure sealing plunger pump in the preferred embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the structure of the spring seal in the preferred embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of the structure of the spring seal ring in the preferred embodiment of the present invention.

[0022] Reference numerals: 100, pump body; 10, plunger cavity; 20, plunger rod; 30, liquid inlet; 31, liquid inlet check valve; 40, liquid outlet; 41, liquid outlet check valve; 50, spring seal; 51, spring; 60, spring seal ring; 70, sealing cavity; 80, adjusting ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited are not intended to limit the present invention.

[0024] As Figure 1 shown, it is a high-pressure sealed plunger pump in an embodiment of the present invention, which includes a pump body 100. A plunger cavity 10 is provided in the pump body 100. A plunger rod 20 is provided in the plunger cavity 10. A liquid inlet 30 and a liquid outlet 40 communicating with the plunger cavity 10 are provided on the pump body 100. A liquid inlet check valve 31 is provided at the liquid inlet 30, and a liquid outlet check valve 41 is provided at the liquid outlet 40.

[0025] A spring seal 50 is provided at the front end of the plunger rod 20. A spring seal ring 60 is sleeved on the plunger rod 20. The sealing surfaces of the spring seal 50 and the spring seal ring 60 are arranged opposite to each other and form a sealing cavity 70. The sealing cavity 70 is filled with a sealing liquid. In this embodiment, the sealing liquid includes water, isopropyl alcohol, etc.

[0026] As Figures 2-3 shown, springs 51 are provided on both the spring seal 50 and the spring seal ring 60. The opening direction of the spring 51 is the sealing surface, that is, the sealing surface of the spring seal 50 is the rear end, and the sealing surface of the spring seal ring 60 is the front end. When the pressure in the sealing cavity 70 increases, the spring seal 50 and the spring seal ring 60 will radially expand under the action of the spring, and the sealing performance is better.

[0027] In order to lock the spring seal 50 and adjust the pressure in the sealing cavity 70, an adjusting ring 80 is sleeved on the plunger rod 20. The adjusting ring 80 abuts against the spring seal ring 60 and adjusts the pressure in the sealing cavity 70. Preferably, the sealing liquid and pressure in the sealing cavity 70 are adjusted according to the liquid to be conveyed.

[0028] Specifically, an external thread is provided on the plunger rod 20, and an internal thread matching the external thread is provided on the adjusting ring 80. The adjusting ring 80 is threadedly connected to the plunger rod 20. By screwing the adjusting ring 80 onto the plunger rod 20, the front end surface of the adjusting ring 80 abuts against the spring seal 50, and the pressure in the sealing cavity 70 is increased by screwing the adjusting ring 80 tightly.

[0029] In this embodiment, the sealing cavity 70 is an annular shape surrounding the plunger rod 20, which can effectively enhance the compressive performance.

[0030] As Figure 2 shown, the front end of the spring seal 50 is a plane that fits the bottom of the plunger cavity 10. Dead angles are avoided, and thus liquid residue is avoided.

[0031] In one embodiment, the front end of the plunger rod 20 is threadedly connected to the spring seal 50. Preferably, the spring seal 50 is provided with a threaded groove or a groove, and the front end of the plunger rod 20 is provided with an external thread that mates with the threaded groove or the groove.

[0032] In another embodiment, the front end of the plunger rod 20 is nested with the spring seal 50.

[0033] The high-pressure seal plunger pump of the present invention forms a seal cavity by arranging a spring seal and a spring seal ring, and arranging the sealing surfaces of the spring seal and the spring seal ring opposite to each other. Sealing liquid is injected into the seal cavity so that the pressure in the seal cavity is greater than the pressure in the plunger cavity when transporting liquid, thereby playing a role in high-pressure sealing of the plunger cavity.

[0034] Secondly, the sealing surface of the spring seal ring (i.e., the spring surface) faces the rear end to avoid dead corners. During liquid replacement, it can be completely cleaned to avoid cross-contamination.

[0035] The above embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A high-pressure sealed plunger pump, characterized in that, Comprising: A pump body, a plunger cavity is provided inside the pump body, a plunger rod is provided inside the plunger cavity, a liquid inlet and a liquid outlet communicating with the plunger cavity are provided on the pump body, a spring seal is provided at the front end of the plunger rod, a spring seal ring is sleeved on the plunger rod, the sealing surfaces of the spring seal and the spring seal ring are arranged opposite to each other to form a sealing cavity, a sealing liquid is injected into the sealing cavity, and the pressure in the sealing cavity is greater than the pressure in the plunger cavity when transporting liquid; when the pressure in the sealing cavity increases, the spring seal expands radially under the action of its spring, and the spring seal ring expands radially under the action of its spring; An adjusting ring is sleeved on the plunger rod, the adjusting ring abuts against the spring seal ring and adjusts the pressure in the sealing cavity so that the pressure in the sealing cavity is greater than the pressure in the plunger cavity when transporting liquid; an external thread is provided on the plunger rod, an internal thread matching the external thread is provided on the adjusting ring, and the adjusting ring is threadedly connected with the plunger rod; The front end of the spring seal is a plane matching the bottom of the plunger cavity.

2. The high-pressure sealed plunger pump according to claim 1, characterized in that, The sealing cavity is annular.

3. The high-pressure sealed plunger pump according to claim 1, characterized in that, The front end of the plunger rod is threadedly connected with the spring seal.

4. The high-pressure sealed plunger pump according to claim 1, wherein Thread grooves or grooves are provided on the spring seal, and external threads matching the thread grooves or grooves are provided at the front end of the plunger rod.

5. The high-pressure sealed plunger pump according to claim 1, characterized in that The front end of the plunger rod is connected with the spring seal by nesting.

6. The high-pressure sealed plunger pump according to claim 1, wherein The sealing liquid includes water and isopropyl alcohol.

7. The high-pressure sealed plunger pump according to claim 1, characterized in that, A liquid inlet check valve is provided at the liquid inlet, and a liquid outlet check valve is provided at the liquid outlet.

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