Liquid inlet and outlet structure of plunger pump and plunger pump

Abstract

The utility model relates to the technical field of ion chromatography detection, in particular to a liquid inlet and outlet structure of a plunger pump and the plunger pump, the liquid inlet and outlet structure is improved, a liquid outlet and a liquid inlet are not in the same radial direction, and the liquid outlet is arranged at the tail end of a pump cavity of the plunger pump. The liquid outlet is formed in the contact position of the pump cavity and the first sealing piece, in this way, a first-in first-out mode is adopted for liquid, namely, the sucked-in liquid is pumped out first when pumped out, dissolved gas or air bubbles and the like in the liquid conveying process are removed in time, the accumulation situation is avoided, meanwhile, the liquid outlet is formed in the position of the sealing piece, and therefore the liquid conveying efficiency is improved. Bubbles accumulated at the first sealing piece for a long time can also be taken out in time when liquid is pumped out, after operation is conducted for a period of time, the conveying flow is stable and high in precision, and compared with the situation that more and more bubbles are accumulated after operation is stable and the conveying flow precision is poor in the prior art, the improvement effect is remarkable.

Description

TECHNICAL FIELD

[0001] The utility model relates to ion chromatography detection technical field, concretely relates to a plunger pump liquid inlet and outlet structure and plunger pump. BACKGROUND

[0002] Ion chromatography analysis is a kind of high performance liquid chromatography technique for separating and quantitatively analyzing ionic compound in solution, and liquid phase conveying precision and stability have extremely important role in ion chromatography detection, are directly related to the accuracy, reproducibility and reliability of analysis result;If liquid phase flow is inaccurate, it can cause retention time variation, affect separation effect;It can cause baseline drift or noise increase, peak area or peak height change, affect detection sensitivity and experimental result consistency and reproducibility etc.;For quantitative analysis, flow precision directly affects detection signal intensity, can cause sample concentration deviation, affect quantitative analysis accuracy. It is found by researchers that the inaccuracy and instability of liquid phase flow are mostly caused by gas in liquid phase, and currently, degassing device is usually introduced, and sample is degassed in sample conveying process, air or dissolved gas contained in the sample is removed, and the problems of poor liquid phase flow precision and unstable liquid phase flow conveying caused by large dead volume are reduced. But it is found by practice that even if liquid phase conveying passes through degassing device, there is still the problems of unstable liquid phase flow conveying and poor precision, so the prior art needs to be further improved. UTILITY MODEL CONTENT

[0003] The utility model aims at providing a plunger pump liquid inlet and outlet structure and plunger pump to solve the prior art problems in the above background.

[0004] To solve the above technical problems, the technical scheme provided by the utility model is as follows:

[0005] On the one hand, the application provides a plunger pump liquid inlet and outlet structure, which comprises a liquid inlet, a liquid outlet, a liquid inlet check valve, a liquid outlet check valve and a first sealing member, the liquid inlet and the liquid outlet are communicated with the plunger pump cavity, the liquid inlet and the liquid outlet are staggered along the radial direction of the plunger pump cavity, the liquid inlet check valve is arranged between the liquid inlet and the plunger pump cavity, the liquid outlet check valve is arranged between the plunger pump cavity and the liquid outlet, and the first sealing member is fixedly arranged at the end of the plunger pump cavity.

[0006] On the basis of the above technical scheme, the liquid inlet is arranged at the first end of the plunger pump cavity, and the liquid outlet is arranged at the end of the plunger pump cavity.

[0007] On the basis of the above technical scheme, the liquid inlet check valve and the liquid outlet check valve are both provided with valve seats, and a reverse taper plug is arranged in the valve seat to fix the liquid inlet pipe on the valve seat.

[0008] In another aspect, the application also provides a plunger pump comprising the plunger pump inlet and outlet structure, and further comprising a pump head, a plunger rod and a pump body, the plunger pump cavity is arranged in the pump head, the pump body is fixedly arranged at the end of the pump head, and the plunger rod is driven to reciprocate in the plunger pump cavity by a driving mechanism.

[0009] On the basis of the above technical solution, the driving mechanism comprises a driving motor, a transmission mechanism and a sliding block, the driving motor is fixedly arranged on the outer wall of the pump body, the sliding block is driven to reciprocate by the driving motor through the transmission mechanism, and the end of the plunger rod is arranged on the sliding block.

[0010] On the basis of the above technical solution, the transmission mechanism comprises a rotating shaft and a cam, the rotating shaft is driven to rotate by the driving motor through a driving assembly, the cam is sleeved on the rotating shaft, and the sliding block is arranged on one side of the cam and is driven to reciprocate by the cam.

[0011] On the basis of the above technical solution, the driving assembly comprises a driving wheel, a synchronous belt and a driven wheel, the driving motor drives the driving wheel to rotate, the driving wheel drives the driven wheel to rotate through the synchronous belt, and the driven wheel is coaxially arranged with the rotating shaft and synchronously rotates.

[0012] On the basis of the above technical solution, the transmission mechanism comprises a lead screw and a nut, the lead screw is driven to rotate by the driving motor, the nut is sleeved on the lead screw and is in sliding connection, and the sliding block is fixedly sleeved on the nut.

[0013] On the basis of the above technical solution, a cleaning cavity is further arranged in the pump head, the first end of the plunger rod is arranged in the plunger pump cavity after penetrating through the cleaning cavity, and a second sealing element is arranged between the plunger rod and the cleaning cavity.

[0014] On the basis of the above technical solution, the first sealing element is a high-pressure sealing ring, and the second sealing element is a low-pressure sealing ring.

[0015] The technical scheme provided by the utility model has the advantages that:

[0016] In the application, the inlet and outlet structure is improved, the outlet and the inlet are not on the same radial, the outlet is arranged at the end of the plunger pump cavity, that is, the outlet is arranged at the contact position of the pump cavity and the first sealing element, in this way, the liquid is pumped out in the first-in first-out mode, the dissolved gas or air bubbles in the liquid conveying process are timely discharged, the accumulation does not occur, the outlet is arranged at the position of the sealing element, the air bubbles accumulated at the first sealing element are timely taken out when the liquid is pumped out, and after a period of operation, the conveying flow is more stable and has high precision. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the internal structure of the utility model;

[0018] Figure 2 is Figure 1 is a partial enlarged view of A in the middle;

[0019] Figure 3 is a schematic diagram of the three-dimensional structure of the plunger pump in the utility model;

[0020] Figure 4 is a sectional view of the pump head in the utility model;

[0021] Figure 5 is a schematic diagram of the structure of the plunger pump after removing the pump body in the utility model;

[0022] Figure 6 is a schematic diagram of the structure of one of the transmission mechanisms in the utility model; DETAILED DESCRIPTION

[0023] The utility model will be further described below in combination with the drawings and examples:

[0024] In the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0025] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "left", "right", "front", "back", "top", "bottom" and the like is based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the utility model and simplifying the description, and not indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model.

[0026] As Figures 1 to 6 shown, in one aspect, the application provides a kind of plunger pump liquid inlet and outlet structure, including inlet 1, outlet 2, inlet check valve 3, outlet check valve 4 and first sealing 5, inlet 1, outlet 2 all are communicated with plunger pump cavity 10, inlet 1 and outlet 2 are staggered along the radial direction of plunger pump cavity 10, inlet check valve 3 is arranged between inlet 1 and plunger pump cavity 10, outlet check valve 4 is arranged between plunger pump cavity 10 and outlet 2, first sealing 5 is fixedly arranged in the end of plunger pump cavity 10.

[0027] On the basis of the above technical solutions, the liquid inlet 1 is arranged at the first end of the plunger pump cavity 10, and the liquid outlet 2 is arranged at the last end of the plunger pump cavity 10.

[0028] In the application, the liquid outlet 2 and the liquid inlet 1 are not arranged on the same radial direction of the plunger pump cavity 10, the liquid outlet 2 is arranged at the last end of the plunger pump cavity 10, that is, the liquid outlet 2 is arranged at the contact position of the plunger pump cavity 10 and the first sealing element 5, in this way, the liquid is pumped out in the first-in first-out mode, the dissolved gas or air bubbles in the liquid conveying process are timely discharged, and the accumulation does not occur, at the same time, the liquid outlet 2 is arranged at the position of the first sealing element 5, the air bubbles accumulated at the first sealing element 5 are also timely discharged when the liquid is pumped out, after a period of operation, the conveying flow is stable and the precision is high, compared with the prior art, the more the air bubbles accumulate after the operation is stable, the lower the conveying flow precision is, and the improvement effect is remarkable.

[0029] In the application, the liquid outlet 2 and the liquid inlet 1 are not arranged on the same radial direction of the plunger pump cavity 10, the liquid outlet 2 is arranged at the last end of the plunger pump cavity 10, that is, the liquid outlet 2 is arranged at the contact position of the plunger pump cavity 10 and the first sealing element 5, in this way, the liquid is pumped out in the first-in first-out mode, the dissolved gas or air bubbles in the liquid conveying process are timely discharged, and the accumulation does not occur, at the same time, the liquid outlet 2 is arranged at the position of the first sealing element 5, the air bubbles accumulated at the first sealing element 5 are also timely discharged when the liquid is pumped out, after a period of operation, the conveying flow is stable and the precision is high, compared with the prior art, the more the air bubbles accumulate after the operation is stable, the lower the conveying flow precision is, and the improvement effect is remarkable.

[0030] On the basis of the above technical solutions, the liquid inlet one-way valve 3 and the liquid outlet one-way valve 4 are both provided with valve seats 6, and the valve seats 6 are provided with inverted taper plugs 61 to fix the liquid inlet pipes 7 on the valve seats 6.

[0031] The inverted taper plug 61 can improve the sealing effect and avoid liquid leakage of the liquid inlet pipe, so that the conveying flow is not deviated and the accuracy of the conveying flow is ensured.

[0032] In another aspect, the application also provides a plunger pump comprising the plunger pump inlet and outlet structure, and further comprising a pump head 20, a plunger rod 30, and a pump body 40, wherein the plunger pump cavity 10 is arranged in the pump head 20, the pump body 40 is fixedly arranged at the end of the pump head 20, and the plunger rod 30 is driven to reciprocate in the plunger pump cavity 10 by a driving mechanism.

[0033] In the application, the plunger pump with the plunger pump inlet and outlet structure is also provided, and the liquid suction and outlet processes are realized by the reciprocating movement of the plunger rod in the pump cavity, so that the mobile phase is stably delivered into the chromatographic analysis system.

[0034] On the basis of the above technical scheme, the driving mechanism comprises a driving motor 50, a transmission mechanism, and a sliding block 60, the driving motor 50 is fixedly arranged on the outer side wall of the pump body 40, the sliding block 60 is driven to reciprocate by the driving motor through the transmission mechanism, and the plunger rod 30 is arranged at the end of the sliding block 60.

[0035] On the basis of the above technical scheme, the transmission mechanism comprises a rotating shaft 71 and a cam 72, the rotating shaft 71 is driven to rotate by the driving motor 50 through a driving assembly, the cam 72 is sleeved on the rotating shaft 71, and the sliding block 60 is arranged on one side of the cam 72 and is driven to reciprocate by the cam 72.

[0036] On the basis of the above technical scheme, the driving assembly comprises a driving wheel 73, a synchronous belt 74, and a driven wheel 75, the driving motor 50 drives the driving wheel 73 to rotate, the driving wheel 73 drives the driven wheel 75 to rotate through the synchronous belt 74, and the driven wheel 75 is coaxially arranged with the rotating shaft 71 and synchronously rotates.

[0037] In the embodiment, the driving mechanism is arranged as a driving mechanism in cooperation with the driving motor 50 and the cam 72, specifically, the driving motor 50 drives the driving wheel 73 to rotate when it works, the driving wheel 73 drives the driven wheel 75 to rotate through the synchronous belt 74, the driven wheel 75 drives the rotating shaft 71 to rotate on the pump body 40, thereby driving the cam 72 to rotate, and the cam 72 drives the sliding block 60 and the plunger rod 30 connected thereto to slide in the plunger pump cavity 10 when it rotates, so as to realize the liquid suction and outlet processes.

[0038] On the basis of the above technical scheme, the reset mechanism for the plunger rod 30 is further arranged, the reset mechanism comprises an elastic member 101 and a fixed pressing plate 102, the fixed pressing plate 102 is fixedly connected with the outer side wall of the pump head 20 through a connecting column 103, the elastic member 101 is sleeved on the plunger rod 30 and abuts against the fixed pressing plate 102 at one end and abuts against the outer side wall of the pump head 20 at the other end.

[0039] By setting the reset mechanism, the return of the plunger rod 30 is realized, that is, the driving mechanism drives the plunger rod 30 to move forward, and then the reset of the plunger rod 30 and the slider 60 is realized under the action of the reset mechanism. Specifically, the fixed pressing plate 102 is fixedly connected with the outer side wall of the pump head 20 through the connecting column 103, one end of the elastic member 101 abuts against the fixed pressing plate 102, and the other end abuts against the outer side wall of the pump head 20. In a preferred embodiment, the elastic member 101 is set as a spring.

[0040] On the basis of the above technical scheme, the transmission mechanism comprises a lead screw 81 and a nut 82, the lead screw 81 is driven to rotate by the driving motor 50, the nut 82 is sleeved on the lead screw 81 and is in sliding connection, and the slider 60 is fixedly sleeved on the nut 82.

[0041] In another preferred embodiment, the driving mechanism can also adopt the mode that the driving motor 50 cooperates with the lead screw nut pair structure to realize the driving of the plunger rod; specifically, the driving motor 50 drives the lead screw 81 to rotate, the nut 82 is sleeved on the lead screw 81 and is in sliding connection, the slider 60 is arranged on the nut 82 and is driven to slide by the nut 82, so as to drive the plunger rod 30 to reciprocate, thereby realizing the processes of liquid suction and liquid discharge.

[0042] On the basis of the above technical scheme, the pump head 20 is further provided with a cleaning cavity 90, the plunger rod 30 is arranged in the plunger pump cavity 10 after the first end of the plunger rod 30 penetrates through the cleaning cavity 90, and the second sealing member 100 is arranged between the plunger rod 30 and the cleaning cavity 90.

[0043] On the basis of the above technical scheme, the first sealing member 5 is set as a high-pressure sealing ring, and the second sealing member 100 is set as a low-pressure sealing ring.

[0044] Through the water inlet 91 and the water outlet 92 arranged on the cleaning cavity 90, the components such as the plunger rod can be cleaned irregularly. Meanwhile, it can be understood that the sealing member is sleeved on the plunger rod, but does not affect the reciprocating motion of the plunger rod, and the sealing member realizes the sealing effect. More preferably, the sealing member adopts a generic packing. The generic packing is a U-shaped Teflon with a special spring, which generates a very excellent sealing effect by the appropriate spring force plus the system fluid pressure to top out the sealing surface and gently press the sealed metal surface. The actuation effect of the spring can overcome the slight eccentricity of the metal fitting surface and the wear of the sealing surface, and continuously maintain the expected sealing performance.

[0045] By setting two sealing elements on the plunger rod, a high-pressure sealing ring is arranged between the plunger rod and the pump cavity, and a low-pressure sealing ring is arranged between the plunger rod and the cleaning cavity, and by arranging the high-pressure sealing ring and the low-pressure sealing ring, the cleaning cavity is arranged between the two sealing rings, which can effectively clean the friction area of the plunger rod and the high-pressure sealing ring, and provide favorable conditions for prolonging the service life of the sealing ring on the pump head.

[0046] It should be noted that the above-mentioned first end and the end are defined according to the direction of liquid conveying, and are only for the convenience of understanding the technical scheme, and do not constitute a limitation on the present application.

[0047] The plunger pump in the present application and several common plunger pumps on the market are tested for liquid delivery accuracy and stability during use, and the results are shown in Table 1. Among them, S S is the pump flow set value error, S R is the pump flow stability, and the self-developed pump is the high-pressure cam pump in the present application.

[0048] As can be seen from Table 1, whether it is the error of the pump flow set value or the stability of the pump flow, the performance of the high-pressure cam pump in the present application is high, according to the test outline of the industry, S S ≤1.0%, S R ≤0.5%, it can be seen that the high-pressure cam pump in the present application can maintain excellent performance in different flow rate states in terms of accuracy and stability, and compared with other several plunger pumps, it has more beneficial technical effects, which is also closely related to the structural improvement of the present application.

[0049] Table 1 Test results of high-pressure cam pump in the present application and other commercially available plunger pumps

[0050]

[0051] The above shows and describes the basic principles and main features of the present application, for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, therefore the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

[0052] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. A liquid inlet and outlet structure of a plunger pump, characterized by comprising: The liquid inlet (1), the liquid outlet (2), the liquid inlet one-way valve (3), the liquid outlet one-way valve (4) and the first sealing element (5) are included, the liquid inlet (1) and the liquid outlet (2) are communicated with the plunger pump cavity (10), the liquid inlet (1) and the liquid outlet (2) are staggered along the radial direction of the plunger pump cavity (10), the liquid inlet one-way valve (3) is arranged between the liquid inlet (1) and the plunger pump cavity (10), the liquid outlet one-way valve (4) is arranged between the plunger pump cavity (10) and the liquid outlet (2), and the first sealing element (5) is fixedly arranged at the end of the plunger pump cavity (10).

2. The liquid inlet and outlet structure of the plunger pump according to claim 1, wherein, The liquid inlet (1) is arranged at the first end of the plunger pump cavity (10), and the liquid outlet (2) is arranged at the end of the plunger pump cavity (10).

3. The liquid inlet and outlet structure of the plunger pump according to claim 1, wherein, The liquid inlet one-way valve (3) and the liquid outlet one-way valve (4) are both provided with valve seats (6), and the valve seats (6) are provided with inverted conical plugs (61) to fix the liquid inlet pipe (7) on the valve seat (6).

4. A piston pump characterized by The plunger pump liquid inlet and outlet structure includes the pump head (20), the plunger rod (30) and the pump body (40), the plunger pump cavity (10) is arranged in the pump head (20), the pump body (40) is fixedly arranged at the end of the pump head (20), and the plunger rod (30) is driven to reciprocate in the plunger pump cavity (10) by the driving mechanism.

5. A piston pump according to claim 4, wherein The driving mechanism includes the driving motor (50), the transmission mechanism and the sliding block (60), the driving motor (50) is fixedly arranged on the outer side wall of the pump body (40), the sliding block (60) is driven to reciprocate by the driving motor through the transmission mechanism, and the end of the plunger rod (30) is arranged on the sliding block (60).

6. A piston pump according to claim 5, wherein The transmission mechanism includes the rotating shaft (71) and the cam (72), the rotating shaft (71) is driven to rotate by the driving motor (50) through the driving assembly, the cam (72) is sleeved on the rotating shaft (71), and the sliding block (60) is arranged on one side of the cam (72) and is driven to reciprocate by the cam (72).

7. A piston pump according to claim 6, wherein The driving assembly includes the driving wheel (73), the synchronous belt (74) and the driven wheel (75), the driving motor (50) drives the driving wheel (73) to rotate, the driving wheel (73) drives the driven wheel (75) to rotate through the synchronous belt (74), and the driven wheel (75) is coaxially arranged with the rotating shaft (71) and is synchronously rotated.

8. A piston pump according to claim 5, wherein The transmission mechanism includes the lead screw (81) and the nut (82), the lead screw (81) is driven to rotate by the driving motor (50), the nut (82) is sleeved on the lead screw (81) and is in sliding connection, and the sliding block (60) is fixedly sleeved on the nut (82).

9. A piston pump according to claim 4, wherein The pump head (20) is further provided with the cleaning cavity (90), the first end of the plunger rod (30) penetrates through the cleaning cavity (90) and is arranged in the plunger pump cavity (10), and the second sealing element (100) is arranged between the plunger rod (30) and the cleaning cavity (90).

10. A piston pump according to claim 9, wherein The first sealing element (5) is arranged as a high-pressure sealing ring, and the second sealing element (100) is arranged as a low-pressure sealing ring.

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