Self-adaptive plunger rod mechanism and high-pressure plunger pump

Abstract

The utility model relates to the technical field of liquid chromatography detection and analysis, in particular to a self-adaptive plunger rod mechanism, which is characterized in that one end of a plunger rod and a floating plate are arranged to form a spherical contact matching structure, and a gap is formed between the floating plate and the inner side wall of a spacer bush in the operation process of a plunger pump, so that the position can be finely adjusted; the corresponding plunger rod can be adjusted in a self-adaptive mode, the problem that the coaxiality and the parallelism of the plunger rod, the pump head and the pump body are inconsistent due to machining errors, assembling errors and the like is solved, and the machining and assembling difficulty is lowered. Meanwhile, the problem that in the plunger pump, especially in a cam driving mode, the plunger rod is abraded by force with the continuously-changing direction in the cam operation process can be effectively solved, the plunger rod can be subjected to self-adaptive adjustment, eccentric abrasion is reduced, the service life is prolonged, and the influence on the liquid conveying amount precision is reduced. Meanwhile, the utility model further provides a high-pressure plunger pump.

Description

Technical Field

[0001] This utility model relates to the field of liquid chromatography detection and analysis technology, specifically to an adaptive plunger rod mechanism and a high-pressure plunger pump. Background Technology

[0002] High-pressure plunger pumps, also known as plunger pumps or reciprocating pumps, are a key component of liquid chromatography (HPLC) systems. They utilize a motor-driven cam mechanism to reciprocate the plunger. When the plunger retracts, it generates negative pressure, drawing the mobile phase into the pump chamber; when the plunger advances, it pushes the mobile phase out at high pressure, delivering it to the chromatographic column. This design allows for high-precision flow control and can withstand high operating pressures, making it ideal for the efficient separation of complex samples in HPLC systems. Currently, during the manufacturing and use of high-pressure plunger pumps, the assembly of multiple components and accumulated tolerances make it difficult to ensure proper coaxiality and parallelism between the pump body and the plunger rod. This can easily lead to uneven wear, affecting the pump's lifespan, and in severe cases, causing the plunger rod to jam between the plunger and pump body, disrupting the normal operation of the HPLC instrument. Utility Model Content

[0003] The purpose of this invention is to provide an adaptive plunger rod mechanism to solve the existing technical problems in the background art.

[0004] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0005] On one hand, this application provides an adaptive plunger rod mechanism, including at least one plunger rod assembly. The plunger rod assembly includes a plunger rod, a spacer, and a floating plate. The spacer is configured as an internally hollow structure. The floating plate is disposed inside the spacer. The outer side wall of the floating plate is spaced apart from the inner side wall of the spacer. One end of the plunger rod extends into the spacer and forms a spherical contact with the floating plate.

[0006] Based on the above technical solution, one end of the plunger rod is provided with a ball head structure, and the end face of the floating plate is provided with a spherical groove that matches the ball head structure.

[0007] Based on the above technical solution, a limiting component is also provided inside the partition sleeve. The limiting component is located on the inner side wall of the partition sleeve and outside the floating plate.

[0008] Based on the above technical solution, a fixing seat is also fixedly installed inside the spacer sleeve. The fixing seat is arranged along the axial direction of the spacer sleeve on the inner side of the floating plate, and the floating plate abuts against one side of the fixing seat.

[0009] On the other hand, this application also provides a high-pressure plunger pump, including the above-mentioned adaptive plunger rod mechanism, and further including a pump head and a pump body. The pump head includes at least one pump chamber, and the pump chamber is provided with an inlet and an outlet. One-way valves are provided between the inlet and the pump chamber and between the pump chamber and the outlet. The plunger rod slides axially in the pump chamber. The pump body is fixedly disposed at one end of the pump head, and the spacer is disposed in the pump body.

[0010] Based on the above technical solution, the pump head includes a first pump chamber and a second pump chamber arranged in series. An inlet check valve is provided between the liquid inlet and the first pump chamber, and an outlet check valve is provided between the first pump chamber and the second pump chamber. A plunger rod is slidably arranged in both the first pump chamber and the second pump chamber.

[0011] Based on the above technical solution, the plunger rod is driven by a drive mechanism to move along the pump body axially. The drive mechanism includes a drive motor, a cam, and a slider. The drive motor is fixedly mounted on the outer wall of the pump body. The cam is driven to rotate by the drive motor through a transmission mechanism. The slider is mounted on one side of the cam and is driven to slide by the cam. The spacer is fixedly mounted on the side of the slider away from the cam.

[0012] Based on the above technical solution, a reset mechanism for the plunger rod to return to its original position is also included. The reset mechanism includes an elastic element, which is sleeved on the plunger rod and has one end abutting against the slider and the other end abutting against the outer wall of the pump head.

[0013] Based on the above technical solution, the pump head includes a first pump head and a second pump head arranged in parallel, the first pump chamber is disposed in the first pump head, and the second pump chamber is disposed in the second pump head.

[0014] Based on the above technical solution, the pump body includes a first pump body corresponding to the first pump head and a second pump body corresponding to the second pump head, wherein the second pump body and the first pump body are arranged side by side.

[0015] The beneficial effects of the technical solution provided by this utility model are as follows:

[0016] This invention provides an adaptive plunger rod mechanism. By setting a spherical contact fit between one end of the plunger rod and the floating plate, the position can be finely adjusted during the operation of the plunger pump due to the gap between the floating plate and the inner wall of the spacer. The plunger rod can then adaptively adjust, improving the inconsistency in coaxiality and parallelism between the plunger rod and the pump head and body caused by machining and assembly errors, thus reducing machining and assembly difficulty. Simultaneously, it effectively improves the wear problem caused by the constantly changing force on the plunger rod during cam operation, especially in cam-driven plunger pumps. The plunger rod can be adaptively adjusted, reducing uneven wear, extending its service life, and minimizing the impact on the accuracy of liquid delivery.

[0017] This invention also provides a high-pressure plunger pump, which realizes the liquid suction and discharge process by reciprocating the plunger rod in the pump chamber, thereby stably delivering the mobile phase to the chromatographic analysis system. The split design of the pump head can reduce the processing difficulty caused by the high parallelism of the two plunger rods and reduce the problem of component wear. At the same time, the pump body is also designed as a split unit, which is especially suitable for high-pressure plunger pumps with large flow rates. The split design can take into account the overall size of the plunger pump and meet the current design requirements for smaller plunger pumps. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the adaptive plunger rod mechanism in this utility model;

[0019] Figure 2 This is a schematic diagram of the piston rod in this utility model;

[0020] Figure 3 This is a schematic diagram of the floating plate in this utility model;

[0021] Figure 4 This is a schematic diagram of the high-pressure plunger pump of this utility model;

[0022] Figure 5 This is a schematic diagram of the high-pressure plunger pump of this utility model after the pump body has been removed;

[0023] Figure 6 This is an internal cross-sectional view of the pump head in this utility model; Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0026] In the description of this utility model, it should be understood that the terms "left", "right", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] like Figures 1 to 6 As shown, this embodiment provides an adaptive plunger rod mechanism, which includes at least one plunger rod assembly. The plunger rod assembly includes a plunger rod 1, a spacer 2, and a floating plate 3. The spacer 2 is configured as an internally hollow structure. The floating plate 3 is disposed inside the spacer 2. The outer side wall of the floating plate 3 is spaced apart from the inner side wall of the spacer 2. One end of the plunger rod 1 extends into the spacer 2 and forms a spherical contact with the floating plate 3.

[0028] This invention provides an adaptive plunger rod mechanism. By setting one end of the plunger rod 1 and the floating plate 3 to form a spherical contact fit structure, during the operation of the plunger pump, the position can be finely adjusted due to the gap between the floating plate 3 and the inner wall of the spacer 2. Correspondingly, the plunger rod 1 can be adaptively adjusted, improving the problem of inconsistent coaxiality and parallelism between the plunger rod 1 and the pump head and pump body caused by machining errors, assembly errors, etc., and reducing the difficulty of machining and assembly. At the same time, it can also effectively improve the wear problem of the plunger rod 1 caused by the constantly changing force during the operation of the cam in the plunger pump, especially in the cam-driven mode. The plunger rod 1 can be adaptively adjusted, reducing uneven wear, extending service life, and reducing the impact on the accuracy of liquid delivery.

[0029] Based on the above technical solution, one end of the plunger rod 1 is provided with a ball head structure 11, and the end face of the floating plate 3 is provided with a spherical groove 31 that is adapted to the ball head structure 11.

[0030] In a preferred embodiment, a ball head structure 11 can be provided at the end of the plunger rod 1, and a spherical groove 31 can be provided on the end face of the floating plate 3. The ball head structure 11 and the spherical groove 31 are adapted to each other to achieve spherical contact, thereby realizing the adaptive adjustment of the plunger rod 1 during the movement.

[0031] In other preferred embodiments, the end of the plunger rod 1 can also be configured as an arc-shaped structure, and the end face structure of the corresponding floating plate 3 can be adaptively adjusted so that spherical contact between the plunger rod 1 and the floating plate 3 can be achieved. If there is inconsistency in coaxiality or parallelism during operation, adaptive adjustment can be performed to reduce uneven wear.

[0032] Based on the above technical solution, a limiting member 21 is also provided inside the spacer 2. The limiting member 21 is provided on the inner side wall of the spacer 2 and located outside the floating plate 3.

[0033] In a preferred embodiment, a limiting element is provided inside the spacer 2 to prevent the floating plate from falling out; in a more preferred embodiment, the limiting element is a sealing ring, specifically, a groove is provided on the inner side wall of the spacer, and the sealing ring is installed in the groove; more preferably, the sealing ring is an O-ring.

[0034] Based on the above technical solution, a fixing seat 22 is also fixedly installed inside the spacer 2. The fixing seat 22 is arranged along the axial direction of the spacer on the inner side of the floating plate, and the floating plate 3 abuts against one side of the fixing seat 22.

[0035] In a preferred embodiment, a fixed seat is provided between the inner side of the floating plate and the bottom of the spacer. The end face of the fixed seat has a high surface finish, resulting in a lower coefficient of friction between the fixed seat and the floating plate during fine-tuning, thus reducing frictional wear on the floating plate. It should be noted that the floating plate abuts against the fixed seat, but this does not affect the movement of the floating plate during fine-tuning.

[0036] This embodiment also provides a high-pressure plunger pump, including the above-mentioned adaptive plunger rod mechanism, and further including a pump head 4 and a pump body 5. The pump head 4 includes at least one pump chamber, and the pump chamber is provided with an inlet 6 and an outlet 7. One-way valves are provided between the inlet 6 and the pump chamber, and between the pump chamber and the outlet 7. The plunger rod 1 slides axially in the pump chamber. The pump body 5 is fixedly installed at one end of the pump head 4, and the spacer 2 is installed inside the pump body 5.

[0037] This embodiment also provides a high-pressure plunger pump with an adaptive plunger rod mechanism. The plunger rod reciprocates within the pump chamber to achieve the liquid intake and discharge process, thereby stably delivering the mobile phase to the chromatographic analysis system.

[0038] Based on the above technical solution, the pump head includes a first pump chamber 8 and a second pump chamber 9 arranged in series. An inlet check valve 101 is provided between the liquid inlet 6 and the first pump chamber 8, and an outlet check valve 102 is provided between the first pump chamber 8 and the second pump chamber 9. A plunger rod 1 is slidably arranged in both the first pump chamber 8 and the second pump chamber 9.

[0039] In a preferred embodiment, by using a series-connected first pump chamber 8 and second pump chamber 9 in combination, periodic operation can introduce the high-pressure sample solution and mobile phase into the chromatographic analysis system at a stable flow rate, ensuring accurate sample detection. A plunger rod is slidably disposed within the first pump chamber 8, and correspondingly, a plunger rod is also slidably disposed within the second pump chamber 9, realizing the liquid absorption and discharge processes of both the first and second pump chambers, thereby achieving stable liquid sample delivery. More preferably, the volume of the first pump chamber 8 is larger than that of the second pump chamber 9, which can be achieved by adjusting the stroke of their respective cams. During liquid absorption in the first pump chamber 8, the outlet check valve 102 is closed, and the second pump chamber 9 outputs the target flow rate of liquid. During liquid discharge in the first pump chamber 8, the inlet check valve 101 is closed, and the outlet check valve 102 is opened. At this time, in addition to outputting the target flow rate of liquid, the first pump chamber 8 also simultaneously outputs the flow rate required for liquid absorption by the second pump chamber 9. With the first pump chamber 8 and second pump chamber 9 operating periodically, continuous and stable liquid delivery can be achieved.

[0040] Based on the above technical solution, the plunger rod is driven by a drive mechanism to move along the axial direction of the pump body 5. The drive mechanism includes a drive motor 12, a cam 13 and a slider 14. The drive motor 12 is fixedly installed on the outer wall of the pump body 5. The cam 13 is driven to rotate by the drive motor 12 through a transmission mechanism. The slider 14 is installed on one side of the cam and is driven to slide by the cam 13. The spacer 2 is fixedly installed on the side of the slider 14 away from the cam 13.

[0041] Based on the above technical solution, the transmission mechanism includes a drive wheel 15, a timing belt 16, a driven wheel 17, and a rotating shaft 18. The drive motor 12 drives the drive wheel 15 to rotate, and the drive wheel 15 drives the driven wheel 17 to rotate through the timing belt 16. The driven wheel 17 and the rotating shaft 18 are coaxially arranged and rotate synchronously. The cam 13 is fixedly sleeved on the rotating shaft 18.

[0042] In this embodiment, the drive mechanism is configured as a drive mechanism in which the drive motor 12 and the cam 13 cooperate; in other preferred embodiments, the drive motor and the ball screw can also be used, as long as the reciprocating motion of the drive piston rod can be achieved.

[0043] Specifically, when the drive motor 12 is working, it drives the drive wheel 15 to rotate. The drive wheel 15 drives the driven wheel 17 to rotate through the synchronous belt 16. The driven wheel 17 drives the rotating shaft 18 to rotate on the pump body 5, thereby driving the cam 13 to rotate. When the cam 13 rotates, it drives the slider 14 and the plunger rod 1 connected to it to slide in the pump chamber, realizing the process of liquid suction and liquid discharge in the pump chamber.

[0044] In a more preferred embodiment, when a first pump chamber 8 and a second pump chamber 9 are provided, the plunger rod in the first pump chamber 8 and the plunger rod in the second pump chamber 9 are both provided with a driving mechanism to drive reciprocating motion; more preferably, the two cams can be simultaneously mounted on the rotating shaft, that is, driven to rotate by one rotating shaft, thereby driving the corresponding slider and the corresponding plunger rod to move, thereby realizing the process of liquid suction and discharge in the first pump chamber 8 and liquid suction and discharge in the second pump chamber 9, thereby realizing the stable delivery of liquid samples.

[0045] Based on the above technical solution, a reset mechanism for returning the plunger rod 1 to its original position is also included. The reset mechanism includes an elastic element 191, which is sleeved on the plunger rod 1 with one end abutting against the slider 14 and the other end abutting against the outer wall of the pump head 4.

[0046] In a preferred embodiment, the reset mechanism further includes a pressure plate 192 and a connecting post 193. The pressure plate 192 is fixedly connected to the outer wall of the pump head 4 via the connecting post 193. One end of the elastic element 191 abuts against the pressure plate 192, and the other end abuts against the outer wall of the pump head 4. In a preferred embodiment, the elastic element 191 is configured as a spring.

[0047] A spring is provided on the plunger rod 1 to facilitate its return. The drive mechanism drives the plunger rod 1 to move forward, and then the plunger rod 1 and the slider 14 are reset under the action of the elastic element 191.

[0048] Based on the above technical solution, the pump head 4 includes a first pump head 41 and a second pump head 42 arranged in parallel, the first pump chamber 8 is disposed in the first pump head 41, and the second pump chamber 9 is disposed in the second pump head 42.

[0049] By designing the pump head in a split configuration, with the plunger rods in the first pump chamber 8 and the second pump chamber 9 respectively positioned within their respective pump heads, the machining difficulty caused by the high parallelism of the two plunger rods can be reduced, thus minimizing component wear.

[0050] Based on the above technical solution, the pump body 5 includes a first pump body corresponding to the first pump head 41 and a second pump body corresponding to the second pump head 42, with the second pump body and the first pump body arranged side by side.

[0051] By designing the pump body 5 as a separate unit, it is particularly suitable for high-pressure plunger pumps with large flow rates. Large flow rates mean large cams, and this separate design can take into account the overall size of the plunger pump, meeting the current design requirements for smaller plunger pumps.

[0052] The foregoing has shown and described the basic principles and main features of this utility model. It is obvious to those skilled in the art that this utility model 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 this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims within this utility model.

[0053] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An adaptive plunger rod mechanism, characterized in that, It includes at least one plunger rod assembly, the plunger rod assembly including a plunger rod (1), a spacer (2) and a floating plate (3), the spacer (2) is configured as an internal hollow structure, the floating plate (3) is disposed inside the spacer (2), the outer side wall of the floating plate (3) is spaced apart from the inner side wall of the spacer (2), and one end of the plunger rod (1) extends into the spacer (2) and forms a spherical contact with the floating plate (3).

2. The adaptive plunger rod mechanism according to claim 1, characterized in that, One end of the plunger rod (1) is provided with a ball head structure (11), and the end face of the floating plate (3) is provided with a spherical groove (31) that is adapted to the ball head structure (11).

3. The adaptive plunger rod mechanism according to claim 1, characterized in that, The spacer (2) is also provided with a limiting member (21), which is located on the inner wall of the spacer (2) and outside the floating plate (3).

4. The adaptive plunger rod mechanism according to claim 1, characterized in that, The spacer (2) is also fixedly provided with a fixed seat (22), which is arranged along the axial direction of the spacer on the inner side of the floating plate, and the floating plate (3) abuts against one side of the fixed seat (22).

5. A high-pressure plunger pump, characterized in that, The adaptive plunger rod mechanism according to any one of claims 1 to 4 further includes a pump head (4) and a pump body (5). The pump head (4) includes at least one pump chamber, on which an inlet (6) and an outlet (7) are provided. A one-way valve is provided between the inlet (6) and the pump chamber, and between the pump chamber and the outlet (7). The plunger rod (1) slides axially within the pump chamber. The pump body (5) is fixedly disposed at one end of the pump head (4), and the spacer (2) is disposed within the pump body (5).

6. A high-pressure plunger pump according to claim 5, characterized in that, The pump head includes a first pump chamber (8) and a second pump chamber (9) arranged in series. An inlet check valve (101) is provided between the inlet port (6) and the first pump chamber (8). An outlet check valve (102) is provided between the first pump chamber (8) and the second pump chamber (9). A plunger rod (1) is slidably arranged in both the first pump chamber (8) and the second pump chamber (9).

7. A high-pressure plunger pump according to claim 5, characterized in that, The plunger rod is driven by a drive mechanism to move axially along the pump body (5). The drive mechanism includes a drive motor (12), a cam (13), and a slider (14). The drive motor (12) is fixedly mounted on the outer wall of the pump body (5). The cam (13) is driven to rotate by the drive motor (12) through a transmission mechanism. The slider (14) is mounted on one side of the cam and is driven to slide by the cam (13). The spacer (2) is fixedly mounted on the side of the slider (14) away from the cam (13).

8. A high-pressure plunger pump according to claim 5, characterized in that, It also includes a reset mechanism for the return of the plunger rod (1), the reset mechanism including an elastic element (191), the elastic element (191) being sleeved on the plunger rod (1) with one end abutting against the slider (14) and the other end abutting against the outer wall of the pump head (4).

9. A high-pressure plunger pump according to claim 6, characterized in that, The pump head (4) includes a first pump head (41) and a second pump head (42) arranged side by side. The first pump chamber (8) is disposed in the first pump head (41), and the second pump chamber (9) is disposed in the second pump head (42).

10. A high-pressure plunger pump according to claim 5, characterized in that, The pump body (5) includes a first pump body corresponding to the first pump head (41) and a second pump body corresponding to the second pump head (42), with the second pump body and the first pump body arranged side by side.

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