Liquid chromatography high-pressure pump

Abstract

The invention provides a liquid chromatography high-pressure pump which comprises a pump head assembly provided with a plunger rod, a support, a top plate, a front plate, a motor assembly, a coded disc assembly, a cam assembly and a push rod suite, and the support, the top plate and the front plate are combined to form a support cavity; the cam assembly and the push rod kit are arranged in a cavity of the support, the pump head assembly is connected with the front plate, the coded disc assembly is arranged on one side of the support, the motor assembly is arranged at the bottom of the support, the motor assembly is connected with the coded disc assembly, the coded disc assembly is connected with the push rod kit, the push rod kit is connected with the cam assembly, and the cam assembly is connected with a plunger rod of the pump head assembly. A one-way valve is arranged in the pump head assembly, and the cam working face of the cam part is an axial curved face. According to the liquid chromatography high-pressure pump, the one-way valve is arranged in the pump head, the cleaning function of a peristaltic pump is integrated to a chromatographic pump and the like, external connecting pieces are reduced, the overall layout occupied space is small, the cost is effectively reduced, the structure is simplified, redundant parts are reduced, the abrasion rate is reduced, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of chromatographic pumps, and in particular to a liquid chromatographic high-pressure pump used for liquid chromatographic analysis. Background Art

[0002] With the development and widespread application of liquid chromatography technology, the requirements for its analysis accuracy, stability and repeatability are getting higher and higher. The liquid chromatography pump is one of the important components of the liquid chromatograph, and its performance directly affects the analysis results. For example, as shown in patent CN 202001243 U, the liquid chromatography pump of the existing liquid chromatograph includes a pump head assembly, a housing, a motor, a circuit control unit and a cam driven by the motor to rotate. The pump head assembly includes a pump head, a pump head seat, a plunger part, a compression spring and a plunger seal. The pump head seat has a cavity, and the plunger part can reciprocate along the axis in the cavity. A roller in contact with the cam is installed at one end of the plunger part, and a fixed plunger is provided at the other end of the plunger part. The plunger seal is an integral structure, and the plunger passes through the plunger seal. The roller contacts the cam of the high-pressure constant current pump. When working, the cam rotates to push the plunger part to reciprocate.

[0003] Chromatographic pumps are divided into two types: parallel pumps and series pumps. The parallel pump head uses a double plunger combined into one to transfer the mobile phase (liquid) to the application end or waste liquid bottle; the series pump head uses a double plunger to transfer the mobile phase (liquid) to the application end or waste liquid bottle in sequence. The commonly used parallel chromatographic pump is a double plunger structure, which is characterized by the phase difference of the two plungers when the pump is working. The pulsation generated when the two plungers work alternately can reduce the total pulsation. When one plunger works to input the mobile phase into the chromatographic column, the other plunger works to suck the mobile phase into the pump cavity and fill the pump cavity, realizing the continuous input of the mobile phase into the chromatographic column.

[0004] There are many pump head structures in the prior art. For example, CN202056032U, CN216477796U, CN112879255A, etc. all have external one-way valves, which take up a large space and require one-way valve sleeves, one-way valve sealing rings for sealing and external auxiliary pipeline connections. The structures are complex, there are many pipelines, and there is a risk of leakage.

[0005] Most existing cams use a double cam structure similar to that shown in the patent "CN2561964Y Double Cam Rotor Vane Pump". This cam structure has poor long-term force stability and is easy to deform. Alternatively, the existing cam uses a disc-shaped double cam structure, which is fixed to the specified position of the stepped shaft with a locking nut, and the other end is supported and installed on the bracket with a roller. The outer cylindrical surface of the cam is the working surface, which is subjected to radial loads frequently for a long time. Therefore, it is very likely to deform or displace the whole radially, resulting in fluctuations in the stroke of the chromatographic pump.

[0006] As one of the core components of the chromatographic pump, the stroke control parts - the cam and roller - require lubricating oil to lubricate the key parts during long-term use to reduce part failure due to wear and affect the overall operation of the liquid chromatography pump. Therefore, the maintenance of the working surface during use has a significant impact on liquid chromatography analysis.

[0007] The plunger rod, one of the core components of the chromatographic pump, will precipitate salt and other crystal structures on the plunger rod during long-term use of conveying liquids. The precipitated crystal structures will wear the plunger rod, which will affect the service life of the plunger rod in the long run. Therefore, its surface cleaning and maintenance during use have a significant impact on liquid chromatography analysis. The commonly used cleaning method is to use an external peristaltic pump to clean the low-pressure area of ​​the pump head. After searching, the invention patent with announcement number CN215089181U discloses an online self-cleaning device for a liquid chromatograph infusion pump. This cleaning device has many additional components and requires a separate peristaltic cleaning pump to provide power.

[0008] In summary, the existing liquid chromatography pump has the following problems: 1. The one-way valve is external, which takes up a lot of space, has many pipelines and a complex structure; 2. The cam structure has poor long-term stress stability and is easy to deform. It is very likely to deform radially or move as a whole, causing fluctuations in the stroke of the chromatographic pump.

[0009] 3. The lubrication effect is poor, resulting in parts failure due to friction; 4. An additional peristaltic pump is required to realize the cleaning function of the plunger rod, and the existing technology does not have a chromatographic pump with an integrated cleaning structure.

[0010] 5. Difficult to maintain, unstable analysis and high cost.

[0011] Therefore, it is of great significance to develop a new type of liquid chromatography high-pressure pump to solve the above technical problems. Summary of the invention

[0012] 1. In view of the problems of the existing pump head structure with external flow path and one-way valve, which occupies a large space, a new pump head structure with simplified structure and built-in one-way valve and internal communication with the flow channel is designed, which eliminates the external one-way valve sleeve, one-way valve sealing ring and external auxiliary pipeline connection, simplifies a large number of external flow channels, can make it thinner, small in size, easy to integrate, low cost, easy to install, and low risk of leakage.

[0013] 2. Improve the cam structure and use the axial load of the cylindrical cam to replace the radial load of the disc cam to ensure the continuous and stable operation of the chromatographic pump while taking into account the cost, processing and installation methods.

[0014] 3. In view of the fact that the existing chromatographic pump needs to add an additional peristaltic pump to realize the cleaning function of the plunger rod, a chromatographic pump with an integrated cleaning structure is designed. The cleaning structure uses the cam assembly of the chromatographic pump to provide a power source for the cleaning liquid, eliminating the peristaltic pump for the cleaning liquid. It has the characteristics of integration, easy maintenance, and low cost.

[0015] 4. By integrating the lubrication structure and the sealing structure into the chromatographic pump, the purpose of automatically maintaining the cam part and the roller of the cam assembly is achieved.

[0016] 5. Aiming at the defects of existing chromatography pumps such as large space occupation, complex structure and relatively high cost, a chromatography pump with relatively simple structure is designed, which has the characteristics of easy maintenance, low cost and high stability.

[0017] A liquid chromatography high-pressure pump comprises a pump head assembly provided with a plunger rod, a bracket, a top plate, a front plate, a motor assembly, a code disk assembly, a cam assembly, and a push rod kit, wherein the bracket, the top plate, and the front plate are combined to form a bracket chamber; the cam assembly and the push rod kit are arranged inside the bracket chamber, the pump head assembly is connected to the front plate, the code disk assembly is arranged on one side of the bracket, the motor assembly is arranged at the bottom of the bracket, the motor assembly is connected to the code disk assembly, the code disk assembly is connected to the push rod kit, the push rod kit is connected to the cam assembly, and the cam assembly is connected to the plunger rod of the pump head assembly; a one-way valve is provided inside the pump head assembly, and the cam working surface of the cam portion is an axial curved surface.

[0018] The code disc assembly comprises a large pulley, a belt, and a small pulley, the belt connects the large pulley and the small pulley, the small pulley is connected to the motor assembly, and the large pulley is connected to the push rod kit.

[0019] Regarding the pump head assembly, it includes a pump head, a pressure plate and at least one plunger rod movably connected to the assembly and the pressure plate, and also includes at least one group of flow channel connecting structures arranged in the pump head assembly and the pressure plate, any group of flow channel connecting structures includes a first one-way valve, a second one-way valve, a first one-way valve flow channel, a second one-way valve flow channel, a third flow channel and a plunger hole, and the plunger rod is movably arranged in the plunger hole; a first one-way valve flow channel is provided inside the first one-way valve, and the lower end of the first one-way valve flow channel is connected to the medium inlet flow channel, a second one-way valve flow channel is provided inside the second one-way valve, and the lower end of the second one-way valve flow channel is connected to the medium outlet flow channel, the upper end of the first one-way valve flow channel is connected to the upper end of the second one-way valve flow channel through the third flow channel, and the third flow channel is connected to at least one plunger hole to form a group of flow channel connecting structures.

[0020] Furthermore, the part of the plunger hole located in the pump head assembly is the high-pressure plunger hole, and the part of the plunger hole located in the pressure plate is the low-pressure plunger hole. The outer wall of the plunger rod is located at the bottom of the high-pressure plunger hole and is provided with a high-pressure sealing ring, and the outer wall of the plunger rod is located at the bottom of the low-pressure plunger hole and is provided with a low-pressure sealing ring. The sealing ring plays a sealing role to prevent leakage of fluid in the plunger hole.

[0021] Furthermore, the lower end of the plunger rod is connected to the plunger seat, and the plunger seat passes through the bottom of the pressure plate. The power provided by the motor drives the plunger rod to move up and down in a reciprocating linear manner through the plunger seat.

[0022] Furthermore, a sealed cavity is provided in the pressure plate, and the plunger rod and the plunger seat are arranged through the cavity, and the cavity provides space conditions for the up and down reciprocating linear motion of the plunger rod.

[0023] Furthermore, it also includes a cleaning pipeline, both ends of which are connected to cleaning interfaces, and the cleaning interfaces are connected to external cleaning equipment. The middle of the cleaning pipeline is connected to the low-pressure plunger hole of the plunger hole of any connecting structure in the flow channel. There is a flowing cleaning solution in the cleaning pipeline, which is used to clean the crystals precipitated on the plunger rod, thereby protecting the plunger rod, and there is no need to remove the plunger rod for cleaning.

[0024] Furthermore, the first one-way valve and the second one-way valve are built into the internal connection between the pump head assembly and the pressure plate. The internal connection is provided with an "O"-shaped fixing ring for fixing the first one-way valve and the second one-way valve. While fixing, it also plays a certain protective role and is easy to install. The one-way valve is built-in, which saves the one-way valve sleeve and sealing structure.

[0025] Furthermore, the high-pressure sealing ring and the low-pressure sealing ring are both wide-seal sealing rings, which have a better sealing effect.

[0026] Furthermore, the first one-way valve and the second one-way valve control the one-way passage of fluid.

[0027] Furthermore, the low-pressure sealing ring is fixed by a fixing member, which may be a hollow screw.

[0028] Furthermore, the flow channel interconnecting structure is two or more groups, and the multiple groups of flow channel interconnecting structures are all connected to the medium inlet flow channel and the medium outlet flow channel; the multiple medium inlet flow channels in the flow channel interconnecting structure are uniformly connected to an inlet, and the multiple medium outlet flow channels in the flow channel interconnecting structure are uniformly connected to an outlet.

[0029] Furthermore, the pump head assembly is provided with a leakage observation hole penetrating the main body, so as to facilitate observation of whether there is leakage inside the pump head assembly when it is working.

[0030] The high-pressure fluid pump includes a liquid chromatography pump, a high-pressure chemical reaction device, a pressure tester, etc.

[0031] Regarding the cam structure, the axial load of the cylindrical cam is used to replace the radial load of the disc cam to ensure the continuous and stable operation of the chromatographic pump while taking into account the cost, processing and installation methods.

[0032] The present invention provides a novel cam structure of a liquid chromatography high-pressure pump, comprising a cam body, wherein the cam body comprises a first shaft portion, a second shaft portion, a cam portion, and a third shaft portion which are arranged in sequence, wherein the first shaft portion is adjacent to the second shaft portion and forms a step shape, and the diameter of the second shaft portion is larger than the diameter of the first shaft portion; the cam portion is adjacent to the second shaft portion, a cam bearing surface is formed on the side of the cam portion close to the second shaft portion, and a cam working surface is formed on the side of the cam portion away from the second shaft portion, and both the cam working surface and the cam bearing surface are perpendicular to the axial direction of the cam portion.

[0033] Furthermore, it also includes a thrust needle roller bearing, and the thrust needle roller bearing is arranged on the second shaft portion.

[0034] Furthermore, it also includes a roller shaft and a roller shaft arranged on the roller shaft, the cam portion is formed with an annular groove, and the roller shaft and the roller shaft are arranged in the annular groove.

[0035] Furthermore, it also includes a gasket, which is arranged between the axial side of the roller and the side wall of the annular groove.

[0036] Furthermore, in the axial direction, the distance between the cam working surface and the cam bearing surface of the cam portion is the cam thickness, the cam thickness is a non-constant value, the cam portion has a widest point and a narrowest point in the axial direction, and the widest point and the narrowest point of the cam portion have a smooth transition.

[0037] Furthermore, the first shaft portion is provided with a keyway.

[0038] Regarding the cleaning structure, it includes a cavity formed by a combination of a bracket, a front plate, and a top plate assembly, a cam assembly is arranged inside the cavity, and also includes at least one cleaning pipe; the cam assembly is provided with a cam shaft and a cam part, the cam part is provided with an annular groove, and the annular groove is provided with at least one roller; the lower end of the top plate assembly is provided with a protrusion, the protrusion is provided with an arc groove, the protrusion is connected with the cam part and the bracket to form a cleaning pipe channel, and the cleaning pipe is arranged in the arc groove of the protrusion and is located above the roller.

[0039] Furthermore, the cam assembly is arranged inside the cavity, one end of which is connected to the front plate, and the other end of which passes through the bracket.

[0040] Furthermore, there are multiple cleaning pipes and multiple rollers, and the cleaning pipes are located above the rollers and are arranged one-to-one with the rollers.

[0041] Furthermore, the plurality of rollers are evenly distributed in the annular groove.

[0042] Furthermore, the camshaft and the cam portion are an integrated structure.

[0043] Furthermore, the cam working surface of the cam portion is an axial curved surface, the cam portion has a widest point and a narrowest point in the axial direction, and there is a smooth transition between the widest point and the narrowest point of the cam portion.

[0044] Furthermore, a fixing structure is provided at the connection point between the protrusion and the bracket.

[0045] Furthermore, the inlet end of the cleaning tube is connected to the cleaning liquid supply end, and the outlet end of the cleaning tube is connected to the inlet end of the cleaning pipeline of the pump head.

[0046] The technical solution of the present invention is: a lubrication and sealing structure, including a bracket kit, a top plate kit and a front plate kit combined to form a bracket chamber; the top plate kit is arranged on the top surface of the bracket kit, the front plate kit is arranged on the side of the bracket kit, at least one sealing strip is used to seal the contact surfaces of the bracket kit, the top plate kit and the front plate kit, and the bottom of the bracket chamber is an area filled with lubricating oil.

[0047] The internal sealing connection is ensured by the sealing strip, and the entire chamber is sealed using double sealing strips + plastic screws. Preferably, there are 2 sealing strips.

[0048] Further, the bracket kit is provided with a cam assembly, the cam assembly is located inside the bracket chamber, one end of the cam assembly is connected to the front plate kit, and the other end passes through the bracket kit, the cam assembly is provided with a cam shaft and a cam part, and the bottom of the cam assembly is located in the area of ​​the bracket chamber filled with lubricating oil. The lubricating oil immerses a part of the cam part.

[0049] Furthermore, an oil drain port is provided on the lower side of the bracket chamber, and the oil drain port is connected to the outside. When sealed, the oil drain port is provided with a PEEK screw to be tightened. When necessary, the lubricating oil can be discharged by opening the PEEK screw, and the lubricating oil can be recovered during maintenance.

[0050] Furthermore, the top plate kit is provided with a detachable observation window, through which lubricating oil can be replenished and injected. The observation window is made of a transparent PMMA plate, through which the internal lubrication condition can be observed at any time.

[0051] Furthermore, the camshaft and the cam portion are an integrated structure, and the cam assembly is a power transmission assembly.

[0052] Furthermore, the cam portion is provided with an annular groove, a plurality of rollers are provided in the annular groove, and the plurality of rollers are evenly distributed in the annular groove. The bottom of the roller is located in the area of ​​the bracket chamber filled with lubricating oil.

[0053] Furthermore, the area 1 / 4-1 / 2 above the bottom of the bracket chamber is filled with lubricating oil, and more preferably the area 1 / 3 above the bottom is filled with lubricating oil.

[0054] 1. Advantages of the whole machine: The liquid chromatography high-pressure pump of the present invention has a one-way valve built into the pump head, and integrates the peristaltic pump cleaning function into the chromatography pump, etc., which reduces external parts, occupies a small space for the overall layout, and effectively reduces costs: simplifies the structure, reduces redundant parts, reduces wear rate, and extends service life.

[0055] The present invention also adopts a double-plunger structure and simplifies the auxiliary parts of the pump head for sealing; at the same time, the peristaltic cleaning structure is integrated into the transmission component to achieve the integration of mobile phase transfer and pump head cleaning; in addition, a sealing structure is set around the transmission component chamber, and lubricating oil is injected into the interior to reduce the wear rate of key components (t cam and roller).

[0056] Functional integration: Integrate the peristaltic pump cleaning function into the chromatography pump to reduce external components.

[0057] The overall layout takes up little space: length*width*height=130.8*76.1*104mm.

[0058] Easy to monitor and maintain: The leakage monitoring hole on the pump head and the transparent observation plate on the top plate can monitor the working status of the pump at any time.

[0059] Effectively reduce costs: Simple structure reduces redundant parts and reduces processing costs.

[0060] 2. Advantages of pump head The pump head structure of the high-pressure fluid pump of the present invention realizes internal installation of the one-way valve by arranging the first one-way valve and the second one-way valve in the pump head, and changes the flow channel that needs to be connected by external connecting parts to be directly processed inside the pump head, thereby reducing the installation space occupied.

[0061] The pump head structure of the high-pressure fluid pump of the present invention is characterized in that a first one-way valve flow channel is provided inside the first one-way valve, a medium liquid inlet flow channel is provided at the lower end of the first one-way valve flow channel, a second one-way valve flow channel is provided inside the second one-way valve, a medium liquid outlet flow channel is provided at the lower end of the first one-way valve flow channel, the first one-way valve flow channel and the second one-way valve flow channel are connected through a third flow channel, and the third flow channel is connected to the plunger hole to form an internal communication structure of the flow channel, thereby simplifying a large number of external flow channels, simplifying pipelines, and facilitating integration.

[0062] The internal flow channel of the pump head structure of the high-pressure fluid pump of the present invention can be directly processed inside the pump head, thereby reducing the occupied installation space.

[0063] 3. Cam Advantages: The working surface (force transmission contact surface) of the cam in the prior art is an outer cylindrical surface. When working, the existing cam is subjected to force in the radial direction, which is easy to deform after long-term use, thus affecting the accuracy of the chromatographic pump. The working surface of the cam of the present invention is an axial surface, and a thrust needle roller bearing is used to bear the axial force, which avoids force deformation in the radial direction, and is conducive to improving the accuracy and stability of the chromatographic pump in long-term operation.

[0064] The cam assembly of the present invention is mainly used to transmit power and control the linear travel of the push rod, including a cam body, a thrust needle roller bearing, a roller, a roller shaft, and a gasket. The cam body (that is, the integrated shaft and cam): used to control the travel of the push rod and support other parts. Being integrated can reduce assembly errors and costs; thrust needle roller bearing: load-bearing parts, axially supporting the cam; the working load of the chromatographic pump is axial force; roller: acts as a peristaltic pump roller; roller shaft: supports the roller; gasket: has a limiting function and accurately positions the roller. Needle roller bearings are used to fix the two ends to the bracket respectively, and a pulley is installed at one shaft end (keyway) to transmit power; a thrust bearing is installed at the shaft step to bear the load; the roller acts as a peristaltic pump roller and has a peristaltic structure with the top plate travel.

[0065] 4. Cleaning structure advantages: 1. The present invention integrates the existing structure and the peristaltic pump cleaning structure into the chromatographic pump. The piping system is distributed on the top plate assembly, and the power system is provided by the camshaft. The inlet and outlet are directly connected to the pump head, reducing the peristaltic pump and other related additional components, reducing costs, improving efficiency, and making it easy to operate and maintain.

[0066] 2. The present invention uses the power provided by the pump head to convert the power of circular motion into the power of circumferential peristalsis through the cam assembly, so that only one power supply structure is required, and no peristaltic pump structure is required for the cleaning structure; it is an automatic cleaning structure with self-driving force.

[0067] 5. Sealing structure advantages: 1. A lubrication and sealing structure of the present invention is provided with lubricating oil which immerses a part of the cam part in the bracket chamber, and the lubricating oil is injected through an observation window, and the observation window can be used to observe the internal lubrication condition. When the liquid chromatography high-pressure pump is working, a part of the key parts immersed in the lubricating oil moves in a circular motion, and the lubricating oil lubricates the key parts, thereby protecting the key parts from failure due to wear. An oil drain port is provided at the lower end of the bracket chamber, and the discharged lubricating oil can be recovered during maintenance.

[0068] 2. The lubrication and sealing structure of the present invention ensures internal sealing connection by using two sealing strips to seal between the contact surfaces of the bracket kit, the top plate kit and the front plate kit.

[0069] 3. The present invention provides a lubricating and sealing structure, wherein the chamber is filled with lubricating oil, which will slowly evaporate after a period of use, thereby making the entire working chamber an environment with lubricating oil. Compared with the prior art method of using lubricating oil in a sponge for local lubrication, the present invention has a better lubrication effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Machine picture: Figure 1 This is the appearance of the entire liquid chromatography high-pressure pump; Figure 2 It is an exploded diagram of a liquid chromatography high pressure pump; Figure 3 is a side view of a liquid chromatography high pressure pump; Figure 4 yes Figure 3 AA cross-sectional diagram of ; Figure 5 yes Figure 4 Schematic diagram of the BB cross section; Figure 6 yes Figure 5 Schematic diagram of the CC cross section; Figure 7 This is a side view of a liquid chromatography high pressure pump. Figure 2 ; Figure 8 yes Figure 7 Schematic diagram of EE cross section; Fig. 9 yes Figure 8 DD cross-sectional diagram of ; Diagram of the pump head structure of the parallel pump: Fig.10 It is a schematic diagram of the overall structure of the pump head assembly of the parallel pump; Fig.11 It is a side structural diagram of a parallel pump head assembly; Fig.12 It is a schematic cross-sectional view of the BB section of the pump head assembly of the parallel pump; Fig.13 It is a schematic cross-sectional view of the AA section of the pump head assembly of the parallel pump; Fig.14 It is a schematic cross-sectional view of the CC section of the parallel pump head assembly; Fig.15 It is a top view of the pump head assembly of the parallel pump; Fig.16 It is a schematic cross-sectional view of the DD section of the pump head assembly of the parallel pump; Fig.17 is a schematic cross-sectional view of the EE section of the parallel pump head assembly; Fig.18 It is a cross-sectional view of the lubrication and sealing structure of a liquid chromatography high-pressure pump; Figure 2. Cleaning structure diagram: Fig.19 It is a front cross-sectional view of a cleaning structure of a liquid chromatography high-pressure pump; Fig. 20 It is a side profile of a cleaning structure of a liquid chromatography high pressure pump; Cam structure diagram: Fig.21 is an axonometric view of the cam assembly; Fig. 22 It is an exploded view of the cam assembly; Fig.23 is a front view of the cam assembly; Fig.24 It is the overall cross-sectional view of the cam assembly; Fig.25 is a cross-sectional view of a cam body of a cam assembly; Fig.26 is an axonometric view of the cam assembly; Fig. 27 It is a partial schematic diagram of the chromatographic pump cam position; Diagram of tandem pumps: Fig.28 It is a schematic diagram of the overall structural breakdown of the pump head structure of the tandem pump; Fig.29 It is a top view of the pump head structure of the tandem pump; Fig.30 It is a schematic diagram of the AA section profile of the pump head structure of the tandem pump; Fig.31 It is a schematic diagram of the BB cross-section of the pump head structure of the tandem pump; Fig.32 It is a schematic diagram of the CC cross-section of the pump head structure of the tandem pump; Fig.33 It is a schematic diagram of the DD cross-section of the pump head structure of the tandem pump; Fig.34 Schematic diagram of the push rod assembly position, (a) is the side view of the push rod assembly, (b) is the schematic diagram of the AA section of the push rod assembly; The numbers in the figure are: 1, pump head assembly; 2, bracket; 3, top plate; 4, front plate; 5, motor assembly; 6, encoder assembly; 7, sensor assembly; 8, cam assembly; 9, push rod kit; 1-1, pump head; 1-11, first plug; 1-12, leakage observation hole; 1-2, pressure plate; 1-21, inlet; 1-22, outlet; 1-23, second plug; 1-3, plunger rod chamber; 1-4, first one-way valve; 1-41, first one-way valve flow channel; 1-42, medium inlet flow channel; 1-5, second one-way valve; 1-51, second one-way valve flow channel; 1-52, medium outlet flow channel; 1-6, plunger rod; 1-61, plunger seat; 1-62, first plunger hole; 1-621, second plunger hole; 1-63, fixing piece; 1-64, high-pressure sealing ring; 1-65, low-pressure sealing ring; 1-66, third flow channel; 1-67, fourth flow channel; 1-68, fifth flow channel; 1-7, cleaning interface; 1-71, cleaning pipeline; 2-1, bracket chamber; 2-2, sealing strip; 2-3, area filled with lubricating oil; 3-1, observation window; 3-2, bump; 3-3, cleaning pipe; 3-4, arc groove; 6-1, large pulley; 6-2, belt; 6-3, small pulley; 8-1, camshaft; 8-11, first shaft portion; 8-12, second shaft portion; 8-13, third shaft portion; 8-14, keyway; 8-2, cam portion; 8-21, annular groove; 8-22, cam working surface; 8-23, cam bearing surface; 8-3, roller; 8-31, first roller shaft; 8-4, thrust needle roller bearing; 8-5, first needle roller bearing; 8-51, second needle roller bearing; 9-1, push rod; 9-2, spring; 9-3, bearing; 9-31, second roller shaft; 9-4, retaining spring. Implementation

[0071] The detailed structure of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0072] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structure of the present invention. Therefore, they may be changed accordingly according to different places, different positions, and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0073] Example 1: Complete machine: Figure 1-9As shown: a liquid chromatography high-pressure pump, including a pump head assembly 1 with a plunger rod, a bracket 2, a top plate 3, a front plate 4, a motor assembly 5, a code disk assembly 6, a cam assembly 8, and a push rod kit 9, the bracket 2, the top plate 3, and the front plate 4 are combined to form a bracket chamber; the cam assembly 8 and the push rod kit 9 ​​are arranged inside the bracket chamber, the pump head assembly 1 is connected to the front plate 3, the code disk assembly 6 is arranged on one side of the bracket, the motor assembly 5 is arranged at the bottom of the bracket, the motor assembly 5 is connected to the code disk assembly 6, the code disk assembly 6 is connected to the push rod kit 9, the push rod kit 9 ​​is connected to the cam assembly 8, and the cam assembly 8 is connected to the plunger rod of the pump head assembly 1; a one-way valve is provided inside the pump head assembly 1, and the cam working surface of the cam assembly is an axial curved surface.

[0074] The code disc assembly 6 includes a large pulley 6-1, a belt 6-2, and a small pulley 6-3, the belt connects the large pulley and the small pulley, the small pulley is connected to the motor assembly 6, and the large pulley is connected to the push rod set 9. The push rod set 9 is a prior art, including a push rod 9-1, a bearing 9-3, a spring 9-2 arranged on the outer periphery of the push rod 9-1, and a second roller shaft 9-31 arranged on the outer periphery of the bearing 9-3.

[0075] Motor assemblies are prior art.

[0076] Working principle: The motor provides power to drive the small pulley 6-3 to rotate, and the small pulley transmits power to the large pulley 6-3 through the belt 6-2. The large pulley 6-3 drives the cam assembly 8 and the shaft to rotate through the flat key; the cam contacts the roller to convert the rotary motion into linear motion, and the guide shaft and the plunger seat are connected by threads and guided by the cam to move linearly, and reset by the spring to achieve reciprocating linear motion. In this way, the liquid is guided to be sucked and discharged, and the cam working surface controls the plunger rod to suck and discharge liquid according to the designed smooth curve, effectively reducing liquid pulsation.

[0077] Component role: Motor assembly: provides power to drive the pulley to move.

[0078] Transmission assembly: transmits power to the actuator and supports the installation of various components.

[0079] Top plate assembly: supports the installation of components, protects and monitors the status of the internal chamber; the bracket, top plate and front plate are combined to form a bracket chamber, providing installation space, etc.

[0080] Pump head assembly: provides flow path and is the main application part.

[0081] Code disc assembly: provides position or speed detection points.

[0082] Sensors may be provided inside the machine to monitor the rotational speed.

[0083] Example 2 Parallel pump head: Figure 10-17 As shown, a high-pressure fluid pump head structure includes a pump head 1-1, a pressure plate 1-2, and a plunger rod 1-6 movably connected to the pump head 1-1 and the pressure plate 1-2, and also includes at least one group of flow channel connecting structures arranged in the pump head 1-1 and the pressure plate 1-2, any group of flow channel connecting structures includes a first one-way valve 1-4, a second one-way valve 1-5, a first one-way valve flow channel 1-41, a second one-way valve flow channel 1-51, a third flow channel 1-66 and a first plunger hole 1-62, the first one-way valve 1-4 and the second one-way valve 1-5 are built into the internal connection between the pump head 1-1 and the pressure plate 1-2, the first one-way valve 1-4 and the second one-way valve 1-5 control the one-way passage of fluid, the A first one-way valve channel 1-41 is provided inside the first one-way valve 1-4, the lower end of which is connected to the medium inlet channel 1-42, and the medium inlet channel 1-42 is connected to the inlet 1-21. A second one-way valve channel 1-51 is provided inside the second one-way valve 1-5, the lower end of which is connected to the medium outlet channel 1-52, and the medium outlet channel 1-52 is connected to the outlet 1-22. The upper end of the first one-way valve channel 1-41 is connected to the upper end of the second one-way valve channel 1-51 through the third channel 1-66, and the third channel 1-66 is connected to the first plunger hole 1-62, forming a group of in-channel connecting structures, the channel There are two groups of internal connecting structures, in which a plurality of medium inlet channels 1-42 in the channel internal connecting structure are uniformly connected to an inlet 1-21, and a plurality of medium outlet channels 1-52 in the channel internal connecting structure are uniformly connected to an outlet 1-22; the medium inlet channels 1-42 are formed by external punching and processing, and a processing hole formed externally during the processing is sealed with a second plug 1-23 after processing; the first plunger hole 1-62 is located in the pump head 1-1 as a high-pressure plunger hole, and the first plunger hole 1-62 is located in the pressure plate 1-2 as a low-pressure plunger hole. The outer wall of the plunger rod 1-6 is located at the bottom of the high-pressure plunger hole and is provided with a high-pressure sealing ring 1-64, and the plunger rod A low-pressure sealing ring 1-65 is provided on the outer wall of 1-6 at the bottom of the low-pressure plunger hole, and the low-pressure sealing ring 1-65 is fixed by a fixing member 1-63, and the high-pressure sealing ring 1-64 and the low-pressure sealing ring 1-65 are both universal sealing rings; the lower end of the plunger rod 1-6 is connected to the plunger seat 1-61, and the plunger seat 1-61 passes through the bottom of the pressure plate 1-2, and the plunger rod 1-6 is movably arranged in the first plunger hole 1-62; a closed plunger rod chamber 1-3 is provided in the pressure plate 1-2, and the plunger rod 1-6 and the plunger seat 1-61 are arranged through this plunger rod chamber 1-3; the pump head 1-1 is provided with a leakage observation hole 1-12 that passes through the body, and the leakage observation hole 1-12 is multiple.

[0084] like Fig.13As shown, a high-pressure fluid pump head structure also includes a cleaning pipe 1-71, both ends of the cleaning pipe 1-7 are connected to the cleaning interface 1-7, the cleaning interface 1-7 is connected to the external cleaning equipment, and the middle of the cleaning pipe 1-71 is connected to the low-pressure plunger hole of the plunger hole of the connecting structure in each flow channel for cleaning the plunger rod 1-6.

[0085] Description of the working process: The lower end of the plunger rod 1-6 is connected to the plunger seat 1-61, and the plunger seat 1-61 passes through the bottom of the pressure plate 1-2, wherein the pressure plate and the transmission component are connected by threads, and the plunger seat and the guide shaft are connected by threads to transmit power to realize linear motion, and the plunger rod 1-6 is movably arranged in the first plunger hole 1-62; a closed plunger rod chamber 1-3 is arranged in the pressure plate 1-2, and the plunger rod 1-6 and the plunger seat 1-61 are arranged through this plunger rod chamber 1-3, and the power provided by the motor drives the plunger rod 1-6 to reciprocate up and down in the plunger rod chamber 1-3 through the plunger seat 1-61. The first one-way valve 1-4 and the second one-way valve 1-5 are built into the internal connection between the pump head 1-1 and the pressure plate 1-2. The first one-way valve 1-4 and the second one-way valve 1-5 are installed using the existing pressure plate as a guide. The channels inside the one-way valves are connected to the channels already provided on the pump head 1-1 and the pressure plate 1-2, and there is no need to use external connectors or other parts to assist in the installation.

[0086] The first one-way valve 1-4 and the second one-way valve 1-5 control the one-way passage of the fluid. A first one-way valve channel 1-41 is provided inside the first one-way valve 1-4, and the lower end of the first one-way valve channel 1-41 is connected to the medium inlet channel 1-42. A second one-way valve channel 1-51 is provided inside the second one-way valve 1-5, and the lower end of the second one-way valve channel 1-51 is connected to the medium outlet channel 1-52. The upper end of the first one-way valve channel 1-41 is connected to the upper end of the second one-way valve channel 1-51 through the third channel 1-66 to form a group of intra-channel connecting structures, and the third channel 1-66 is connected to the first plunger hole 1-62.

[0087] The third flow channel 1-66 is formed by external punching processing. The processing hole is formed externally during the processing, and the processing hole is sealed with the first plug 1-11 after the processing.

[0088] In this embodiment, there are two groups of connecting structures in the flow channel, and multiple groups of connecting structures in the flow channel are set to increase the volume of suction and discharge; when the plunger rod 1-6 moves downward, the two groups of medium inlet flow channels 1-42 are connected to the inlet 1-21. After the fluid enters the two groups of medium inlet flow channels 1-42 from the inlet 1-21, it passes through the first one-way valve flow channel 1-41, the third flow channel 1-66, the first plunger hole 1-62, the third flow channel 1-66, and the second one-way valve flow channel 1-51 in sequence, and the fluid flows out of the medium outlet flow channel 1-52. The two groups of medium outlet flow channels 1-52 are connected to the outlet 1-22, and the fluid flows out from the outlet 1-22. With the up and down reciprocating linear motion of the plunger rod 1-6, the volume of the working chamber is changed, driving the continuous suction and discharge of the fluid in the flow channel. The working chamber is the cavity at the intersection of the third flow channel 1-66 and the first plunger hole 1-62.

[0089] At the same time, it also includes a cleaning pipe 1-71, both ends of the cleaning pipe 1-71 are connected to the cleaning interface 1-7, the cleaning interface 1-7 is connected to the external cleaning equipment, the middle of the cleaning pipe 1-71 is connected to the low-pressure plunger hole of the plunger hole of each connecting structure in the flow channel, the connecting structure in the flow channel is divided into two groups, while the fluid in the flow channel is continuously sucked and discharged, the external cleaning equipment also operates at the same time, the cleaning solution enters the cleaning pipe 1-71 through the cleaning interface 1-7, the cleaning solution enters the low-pressure plunger hole of the plunger hole from the cleaning pipe 1-71, the flowing cleaning solution takes away the crystals precipitated on the two groups of plunger rods 1-6 located in the same straight line, and flows out through the cleaning pipe 1-71 and the cleaning interface 1-7 at the other end, completing the cleaning work of the plunger rod 1-6.

[0090] The present invention provides a new pump head structure with a simplified structure and a built-in one-way valve and a communication channel, eliminating the external one-way valve sleeve, the one-way valve sealing ring seal and the external auxiliary pipeline connection, simplifying a large number of external flow channels, and enabling the preparation of a thinner pump head structure with a small volume. A specific comparison with existing products is shown in Table 1.

[0091] Table 1 Comparison of the pump head volumes of the pump head of the present invention and other pump heads

[0092] Example 3 Sealing structure example: Fig.18 As shown: a lubrication and sealing structure, comprising a bracket 2, a top plate 3 and a front plate set 3, which are combined to form a bracket chamber 2-1; the top plate 3 is arranged on the top surface of the bracket 2, the front plate set 3 is arranged on the side of the bracket 2, and two sealing strips 2-2 are respectively used to seal the contact surfaces of the bracket 2, the top plate 3 and the front plate set 3. The bottom of the bracket chamber is an area 2-3 filled with lubricating oil.

[0093] The bracket 2 is provided with a cam assembly 8, which is located inside the bracket chamber 2-1, one end of which is connected to the front plate set 3, and the other end is set through the bracket 2. The cam assembly 8 is provided with a cam shaft 8-1 and a cam part 8-2, and the bracket chamber 2-1 is filled with lubricating oil that partially immerses the cam part 8-2. The area of ​​the bracket chamber from the bottom to the top 1 / 3 is the area 2-3 filled with lubricating oil.

[0094] like Figure 2 As shown, an oil drain port 13 is provided at the lower end of the bracket chamber 2 - 1 , the oil drain port 13 is connected to the outside, and the oil drain port 13 is provided with a PEEK screw for tightening.

[0095] The top plate 3 is provided with a detachable observation window 3-1. The camshaft 8-1 and the cam portion 8-2 are an integrated structure, and the cam assembly 8 is a power transmission assembly. The cam portion 8-2 is provided with an annular groove 8-21, and a plurality of rollers 8-3 are provided in the annular groove 8-21, and the plurality of rollers 8-3 are evenly distributed in the annular groove 8-21.

[0096] Principle description: A lubrication and sealing structure, including a bracket 2, a top plate 3 and a front plate set 3, which are combined to form a bracket chamber 2-1; two sealing strips 2-2 are used to seal the contact surfaces of the bracket 2, the top plate 3 and the front plate set 3, and the top plate 3 is provided with a detachable observation window 3-1. Lubricating oil is injected into the bracket chamber 2-1 through the observation window 3-1, and the injected lubricating oil immerses a part of the cam part 8-2. The camshaft 8-1 and the cam part 8-2 are an integrated structure. The cam assembly 8 is a power transmission assembly. The power drives the cam part 8-2 to make a circular motion through the camshaft 8-1. Each time the cam part 8-2 moves, it will pass through the lubricating oil in the bracket chamber 2-1, thereby being lubricated and protecting key components from failure due to wear. After a period of use, the lubricating oil can be discharged and recovered through the oil drain port 13 at the lower end of the bracket chamber 2-1. The oil drain port 13 is provided with a PEEK screw to tighten. When the oil drain port 13 is opened for maintenance, the lubricating oil can be discharged and recovered.

[0097] Example 4 Cleaning structure example: Figure 2 , 19 -20 shows: a cleaning structure, including a cavity formed by a combination of a bracket 2, a front plate 4, and a top plate 3, a cam assembly 8 is arranged inside the cavity, and also includes at least one cleaning pipe 3-3; the cam assembly 8 is provided with a cam shaft 8-1 and a cam portion 8-2, the cam portion 8-2 is provided with an annular groove 8-21, and the annular groove 8-21 is provided with at least one roller 8-3; the lower end of the top plate 3 is provided with a protrusion 3-2, the protrusion 3-2 is provided with an arc groove 3-4, the protrusion 3-2 is connected with the cam portion 8-2 and the bracket 2 to form a cleaning pipe channel, and the cleaning pipe 3-3 is arranged in the arc groove 3-4 of the protrusion 3-2 and is located above the roller 8-3.

[0098] In this embodiment, the camshaft 8-1 and the cam portion 8-2 are an integrated structure. The cam assembly 8 is disposed inside the cavity, one end of which is connected to the front plate 4, and the other end of which is disposed through the bracket 2. The cam assembly 8 is a power transmission assembly.

[0099] There are multiple cleaning pipes 3-3, multiple rollers 8-3, and the cleaning pipes 3-3 are located above the rollers 8-3 and are arranged one by one with the rollers 8-3. The multiple rollers 8-3 are evenly distributed in the annular groove 8-21. The rollers are preferably deep groove ball bearings.

[0100] The inlet end of the cleaning tube 3-3 is connected to the cleaning liquid supply end, and the outlet end of the cleaning tube 3-3 is connected to the inlet end of the cleaning pipeline of the pump head. In this embodiment, the cleaning tube 3-3 is a silicone tube.

[0101] The cam working surface 8-22 of the cam portion 8-2 is an axial curved surface, and the cam portion 8-2 has a widest point and a narrowest point in the axial direction, and the widest point and the narrowest point of the cam portion 8-2 have a smooth transition. This structure can make the push rod assembly reciprocate in the radial direction of the cam body, produce a stroke change, and avoid force deformation in the radial direction.

[0102] A fixing structure 34 is provided at the connection between the protrusion 3-2 and the bracket 2. In this embodiment, a small section of stainless steel pipe is placed at both ends of the cleaning pipe 3-3 as a fixing device to prevent the entire pipeline from moving.

[0103] The bracket 2 is used for installation and positioning and installation of other parts. The front plate 4 is used for positioning and connecting the camshaft 8-1 and the top plate 3. The top plate 3 is used for shaping, installation and limiting of the cleaning pipe 3-3.

[0104] The cam assembly 8 in the present invention is a power transmission assembly. The motor is synchronously driven to transmit power to the cam assembly 8 by driving the driving pulley. The power drives the cam shaft 8-1 to rotate. The cam shaft 8-1 drives the roller 8-3 in the annular groove 8-21 to rotate. A cleaning tube 3-3 is arranged above the roller 8-3. The cleaning tube 3-3 is filled with cleaning liquid. The liquid in the cleaning tube 3-3 is connected to the cleaning liquid providing device. The outlet of the cleaning tube 3-3 is connected to the cleaning liquid inlet of the pump head. When the cleaning liquid in the cleaning tube 3-3 reaches the top of the roller 8-3, the cam structure rotates to drive the roller 8-3 to continuously squeeze the cleaning tube 3-3, providing power for the cleaning liquid in the cleaning tube 3-3, so that the cleaning liquid in the cleaning tube 3-3 flows forward between the two rollers 8-3. The cleaning liquid flows forward to the low-pressure sealing area of ​​the pump head plunger rod, and the flowing cleaning liquid takes away the crystals precipitated on the outer wall of the plunger rod. The crystals are discharged with the cleaning liquid, thereby achieving a cleaning effect and completing the cleaning work of the liquid chromatography high-pressure pump.

[0105] The present invention integrates the existing structure and the peristaltic pump cleaning structure into the chromatographic pump. The pipeline system is distributed on the top plate assembly, and the power system is provided by the camshaft, thereby reducing the peristaltic pump and other related additional components, and is easy to operate and maintain.

[0106] Embodiment 5 Embodiment of the cam: See attached Figure 21-27 The present invention provides a novel cam structure of a liquid chromatography high-pressure pump, including a cam assembly 8, wherein the cam assembly 8 includes a first shaft portion 8-11, a second shaft portion 8-12, a cam portion 8-2, and a third shaft portion 8-13 arranged in sequence, wherein the first shaft portion 8-11 is adjacent to the second shaft portion 8-12 and forms a step shape, and the diameter of the second shaft portion 8-12 is larger than the diameter of the first shaft portion 8-11; the cam portion 8-2 is adjacent to the second shaft portion 8-12, and a cam bearing surface 8-23 is formed on the side of the cam portion 8-2 close to the second shaft portion 8-12, and a cam working surface 8-22 is formed on the side of the cam portion 8-2 away from the second shaft portion 8-12, and the cam working surface 8-22 and the cam bearing surface 8-23 are both perpendicular to the axial direction of the cam portion 8-2.

[0107] The first shaft portion 8-11 and the third shaft portion 8-13 at both ends of the cam assembly 8 are respectively arranged in the chromatographic pump, and specifically can be respectively fixed on the first needle bearing 8-5 and the second needle bearing 8-51 of the chromatographic pump; the first shaft portion 8-11 is connected to one of the power ends of the chromatographic pump, and specifically can be that the first shaft portion 8-11 is provided with a keyway to be connected with the pulley of the chromatographic pump, so as to improve the transmission efficiency. Taking the cam assembly 8 as a separate entity, the end connected to the pulley of the chromatographic pump is the power input end, and the cam working surface 8-22 is the power output end. The cam working surface 8-22 is connected to the push rod kit 9 ​​of the chromatographic pump, so as to output and transmit the power to the push rod kit, and the cam assembly 8 completes the power transmission.

[0108] In the prior art, the working surface (force transmission contact surface) of the existing cam is an outer cylindrical surface. When working, the existing cam is subjected to force in the radial direction, which is easy to cause deformation after long-term use, thereby affecting the accuracy of the chromatographic pump. However, the working surface of the cam of the present invention is subjected to force in the axial direction, avoiding deformation due to force in the radial direction, which is conducive to improving the accuracy and stability of the chromatographic pump in long-term operation.

[0109] Furthermore, it also includes a thrust needle roller bearing 8-4, which is arranged on the second shaft portion 8-12, specifically on the side opposite to the cam working surface 8-22, to bear the axial force of the cam working surface 8-22 when it is working.

[0110] Further, it also includes a first roller shaft 8-31, a roller shaft 8-3 arranged on the first roller shaft 8-31, the cam portion 8-2 is formed with an annular groove 8-21, the first roller shaft 8-31 and the roller shaft 8-3 are arranged in the annular groove 8-21, see Fig. 27 A silicone tube is provided between the top plate 3 and the roller 8-3, and the roller 8-3 and the top plate 3 form a peristaltic structure. The 6 pairs of rollers are evenly distributed around the circumference and spaced 60° apart. During operation, the inner ring of the bearing is fixed and the outer ring rotates. The silicone tubes installed on the top plate are compressed between the two to form a closed fluid area, and the fluid moves forward continuously as a whole with the help of the rotating thrust of the cam. The outlet is connected to the pump head to achieve the effect of cleaning the plunger rod.

[0111] Furthermore, if Fig.24 As shown, it also includes a gasket, which is arranged between the axial side of the roller 8-3 and the side wall of the annular groove 8-21 to play a limiting role so that the roller can be accurately positioned.

[0112] Further, in the axial direction, the distance between the cam working surface 8-22 and the cam bearing surface 8-23 of the cam portion 8-2 is the cam thickness, and the cam thickness is a non-constant value. The cam portion 8-2 has a widest point and a narrowest point in the axial direction, and there is a smooth transition between the widest point and the narrowest point of the cam portion 8-2. This structure can make the push rod set 9 reciprocate in the radial direction of the cam body to produce a stroke change. That is, the cam working surface 8-22 is an axial curved surface, and a thrust needle roller bearing is used to bear the axial force, ensuring that the cam is subjected to force for a long time without failure.

[0113] Furthermore, the first shaft portion is provided with keyways 8-14 to improve the stability and reliability of the connection.

[0114] Example 6 Example of a series pump head: Figures 28 to 33 As shown, a pump head structure of a tandem pump includes a pump head 1-1, a pressure plate 1-2, and at least two plunger rods 1-6 movably connected to the pump head 1-1 and the pressure plate 1-2, and also includes at least one group of flow channel communication structures arranged in the pump head 1-1 and the pressure plate 1-2, any group of flow channel communication structures includes a first one-way valve 1-4, a second one-way valve 1-5, a first one-way valve flow channel 1-41, a second one-way valve flow channel 1-51, a third flow channel 1-66, a fourth flow channel The third flow channel 1-66 is connected to the first plunger hole 1-62 at the middle position, and the fourth flow channel 1-67 is connected to the second first plunger hole 1-621 at the middle position; the first one-way valve 1-4 is provided with a first one-way valve flow channel 1-41 inside, and the second one-way valve 1-5 is provided with a second one-way valve flow channel 1-51 inside.

[0115] The outlet end of the first one-way valve channel 1-41 is connected to the inlet end of the third channel 1-66, the outlet end of the third channel 1-66 is connected to the inlet end of the second one-way valve channel 1-51, and the outlet end of the second one-way valve channel 1-51 is connected to the inlet end of the fourth channel 1-67 to form a group of intra-channel connecting structures.

[0116] The inlet end of the first one-way valve channel 1-41 is connected to the medium inlet channel 1-42, the outlet end of the fourth channel 1-67 is connected to the inlet end of the first one-way valve channel 1-41 of the connecting structure in the next group of channels (in the case of multiple groups connected in series) or directly connected to the inlet end of the fifth channel 1-68, and the outlet end of the fifth channel 1-68 is connected to the medium outlet channel 1-52 (in the case of one group connected in series).

[0117] The transverse parts of the third flow channel 1-66 and the fourth flow channel 1-67 are formed by external punching processing. The processing holes formed externally during the processing are sealed with the first plug 1-11 after processing. The part of the plunger hole located in the pump head 1-1 is the high-pressure plunger hole, and the part of the plunger hole located in the pressure plate 1-2 is the low-pressure plunger hole. The outer wall of the plunger rod 1-6 is located at the bottom of the high-pressure plunger hole and is provided with a high-pressure sealing ring 1-64. The outer wall of the plunger rod 1-6 is located at the bottom of the low-pressure plunger hole and is provided with a low-pressure sealing ring 1-65. The low-pressure sealing ring 1-6 The plunger rod 1-6 is fixed by a fixing member 1-63, and the high-pressure sealing ring 1-64 and the low-pressure sealing ring 1-65 are both pan-seal rings; the lower end of the plunger rod 1-6 is connected to the plunger seat 1-61, and the plunger seat 1-61 passes through the bottom of the pressing plate 1-2, and the plunger rod 1-6 is movably arranged in the plunger hole; a sealed plunger rod chamber 1-3 is arranged in the pressing plate 1-2, and the plunger rod 1-6 and the plunger seat 1-61 pass through the plunger rod chamber 1-3; the pump head 1-1 is provided with a leakage observation hole 1-12 that passes through the body, and the leakage observation hole 1-12 is multiple.

[0118] like Fig.13 As shown, a pump head structure of a series pump also includes a cleaning pipe 1-71, both ends of the cleaning pipe 1-71 are connected to cleaning interfaces 1-7, the cleaning interface 1-7 is connected to an external cleaning device, and the middle of the cleaning pipe 1-71 is connected to the low-pressure plunger hole of the plunger hole of the connecting structure in each flow channel for cleaning the plunger rod 1-6.

[0119] Description of the working process: The lower end of the plunger rod 1-6 is connected to the plunger seat 1-61, and the plunger seat 1-61 passes through the bottom of the pressure plate 1-2, wherein the pressure plate and the transmission component are connected by threads, and the plunger seat and the guide shaft are connected by threads to transmit power to achieve linear motion, and the plunger rod 1-6 is movably arranged in the plunger hole; a closed plunger rod chamber 1-3 is arranged in the pressure plate 1-2, and the plunger rod 1-6 and the plunger seat 1-61 are arranged through this plunger rod chamber 1-3, and the power provided by the motor drives the plunger rod 1-6 to reciprocate up and down in the plunger rod chamber 1-3 through the plunger seat 1-61. The first one-way valve 1-4 and the second one-way valve 1-5 are built into the internal connection between the pump head 1-1 and the pressure plate 1-2. The first one-way valve 1-4 and the second one-way valve 1-5 are installed using the existing pressure plate as a guide. The channels inside the one-way valves are connected to the channels already provided on the pump head 1-1 and the pressure plate 1-2, and there is no need to use external connectors or other parts to assist in the installation.

[0120] The first one-way valve 1-4 and the second one-way valve 1-5 control the one-way passage of the fluid. The lower end of the first one-way valve channel 1-41 is connected to the medium inlet channel 1-42. The fourth channel 1-67 is connected to the first one-way valve channel 1-41 of the next group of channel interconnection structures or directly connected to the fifth channel 1-68. The fifth channel 1-68 is connected to the medium outlet channel 1-52 to form a group of channel interconnection structures.

[0121] The connecting structure in the flow channel is at least one group, and at least two plunger rods 1-6 are provided to increase the speed of suction and discharge; when the plunger rod 1-6 moves downward, the medium liquid inlet flow channel 1-42 is connected to the inlet 1-21, and after the fluid enters the medium liquid inlet flow channel 1-42 from the inlet 1-21, it passes through a one-way valve flow channel 31, the third flow channel 1-66, the first plunger hole 1-62, the third flow channel 1-66, the second one-way valve flow channel 1-51, the fourth flow channel 1-67, the second first plunger hole 1-621, and the fourth flow channel 1-67 in one direction in sequence.

[0122] When there are multiple groups of connecting structures in the flow channel (multiple groups connected in series), the fluid in the fourth flow channel 1-67 is connected to the first one-way valve flow channel 1-41 of the connecting structure in the next group of flow channels, until the fourth flow channel 1-67 of the last group is directly connected to the fifth flow channel 1-68, and the fifth flow channel 1-68 is connected to the medium outlet flow channel 1-52.

[0123] When the connecting structure in the flow channel is a group (a group connected in series), the fluid in the fourth flow channel 1-67 is directly connected to the fifth flow channel 1-68, and the fifth flow channel 1-68 is connected to the medium outlet flow channel 1-52; the medium outlet flow channel 1-52 is connected to the outlet 1-22, and the fluid flows out from the outlet 1-22. As the plunger rod 1-6 moves up and down in a straight line, the volume of the working chamber changes, driving the continuous suction and discharge of the fluid in the flow channel. The working chamber is the cavity at the intersection of the third flow channel 1-66 and the first plunger hole 1-62 and the cavity at the intersection of the fourth flow channel 1-67 and the second first plunger hole 1-621.

[0124] At the same time, it also includes a cleaning pipe 1-71, both ends of the cleaning pipe 1-71 are connected to the cleaning interface 1-7, the cleaning interface 1-7 is connected to the external cleaning equipment, the middle of the cleaning pipe 1-71 is connected to the low-pressure plunger hole of the plunger hole of the connecting structure in the flow channel, and the external cleaning equipment is also operated while the fluid in the flow channel is continuously sucked and discharged. The cleaning solution enters the cleaning pipe 1-71 through the cleaning interface 1-7, and the cleaning solution enters the low-pressure plunger hole of the plunger hole from the cleaning pipe 1-71. The flowing cleaning solution carries away the crystals precipitated on the two groups of plunger rods 1-6 located in the same straight line, and flows out through the cleaning pipe 1-71 and the cleaning interface 1-7 at the other end, completing the cleaning of the plunger rod 1-6.

[0125] The pump head volume of the series pump is the same as the pump head structure volume of the parallel pump, but the internal connection relationship is different.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A liquid chromatography high pressure pump, comprising a pump head assembly with a plunger rod, a bracket, a top plate, a front plate, a motor assembly, a code disc assembly, a cam assembly, and a push rod kit, characterized in that: The bracket, top plate, and front plate are combined to form a bracket chamber; the cam assembly and the push rod kit are arranged inside the bracket chamber, the pump head assembly is connected to the front plate, the code disk assembly is arranged on one side of the bracket, the motor assembly is arranged at the bottom of the bracket, the motor assembly is connected to the code disk assembly, the code disk assembly is connected to the push rod kit, the push rod kit is connected to the cam assembly, and the cam assembly is connected to the plunger rod of the pump head assembly; a one-way valve is provided inside the pump head assembly, and the cam working surface of the cam part is an axial curved surface.

2. The liquid chromatography high pressure pump according to claim 1, characterized in that: The pump head assembly includes a pump head, a pressure plate and at least one plunger rod movably connected to the assembly and the pressure plate, and also includes at least one group of flow channel communication structures arranged in the pump head assembly and the pressure plate, any group of flow channel communication structures includes a first one-way valve, a second one-way valve, a first one-way valve flow channel, a second one-way valve flow channel, a third flow channel and a plunger hole, and the plunger rod is movably arranged in the plunger hole; a first one-way valve flow channel is provided inside the first one-way valve, and the lower end of the first one-way valve flow channel is connected to the medium inlet flow channel, a second one-way valve flow channel is provided inside the second one-way valve, and the lower end of the second one-way valve flow channel is connected to the medium outlet flow channel, the upper end of the first one-way valve flow channel is connected to the upper end of the second one-way valve flow channel through the third flow channel, and the third flow channel is connected to at least one plunger hole to form a group of flow channel communication structures.

3. The liquid chromatography high pressure pump according to claim 2, characterized in that: The part of the plunger hole located in the pump head assembly is the high-pressure plunger hole, and the part of the plunger hole located in the pressure plate is the low-pressure plunger hole. The outer wall of the plunger rod is located at the bottom of the high-pressure plunger hole and is provided with a high-pressure sealing ring, and the outer wall of the plunger rod is located at the bottom of the low-pressure plunger hole and is provided with a low-pressure sealing ring.

4. The liquid chromatography high pressure pump according to claim 2, characterized in that: The lower end of the plunger rod is connected to the plunger seat, and the plunger seat passes through the bottom of the pressing plate.

5. The liquid chromatography high pressure pump according to claim 2, characterized in that: A sealed cavity is arranged in the pressing plate, and the plunger rod and the plunger seat are arranged through the cavity.

6. The liquid chromatography high pressure pump according to claim 2, characterized in that: It also includes a cleaning pipeline, both ends of which are connected to cleaning interfaces, and the middle of the cleaning pipeline is connected to a low-pressure plunger hole of a plunger hole of any one of the communicating structures in the flow channel.

7. The liquid chromatography high pressure pump according to claim 1, characterized in that: The cam structure includes a cam body, which includes a first shaft portion, a second shaft portion, a cam portion, and a third shaft portion arranged in sequence, wherein the first shaft portion is adjacent to the second shaft portion and forms a step shape, and the diameter of the second shaft portion is larger than the diameter of the first shaft portion; the cam portion is adjacent to the second shaft portion, and a cam bearing surface is formed on the side of the cam portion close to the second shaft portion, and a cam working surface is formed on the side of the cam portion away from the second shaft portion, and the cam working surface and the cam bearing surface are both perpendicular to the axial direction of the cam portion.

8. The liquid chromatography high pressure pump according to claim 7, characterized in that: Also included is a thrust needle roller bearing disposed on the second shaft portion.

9. The liquid chromatography high pressure pump according to claim 7, characterized in that: It also includes a roller shaft and a roller shaft arranged on the roller shaft, the cam portion is formed with an annular groove, and the roller shaft and the roller shaft are arranged in the annular groove.

10. The liquid chromatography high pressure pump according to claim 7, characterized in that: In the axial direction, the distance between the cam working surface and the cam bearing surface of the cam portion is the cam thickness, and the cam thickness is a non-constant value. The cam portion has a widest point and a narrowest point in the axial direction, and there is a smooth transition between the widest point and the narrowest point of the cam portion.

11. The liquid chromatography high pressure pump according to claim 1, characterized in that: It also includes at least one cleaning pipe; the cam assembly is provided with a camshaft and a cam portion, the cam portion is provided with an annular groove, and at least one roller is provided in the annular groove; a protrusion is provided at the lower end of the top plate assembly, and an arc groove is provided in the protrusion, the protrusion is connected with the cam portion and the bracket to form a cleaning pipe channel, and the cleaning pipe is arranged in the arc groove of the protrusion and is located above the roller.

12. The liquid chromatography high pressure pump according to claim 11, characterized in that: The inlet end of the cleaning tube is connected to the cleaning liquid supply end, and the outlet end of the cleaning tube is connected to the inlet end of the cleaning pipeline of the pump head.

13. The liquid chromatography high pressure pump according to claim 1, characterized in that: The contact surfaces of the support kit, the top plate kit and the front plate kit are sealed by at least one sealing strip, and the bottom of the support chamber is an area filled with lubricating oil.

14. The liquid chromatography high pressure pump according to claim 13, characterized in that: The bottom of the cam assembly is located in an area where the bracket chamber is filled with lubricating oil, and the lubricating oil immerses a part of the cam portion.

15. The liquid chromatography high pressure pump according to claim 14, characterized in that: The area 1 / 4-1 / 2 above the bottom of the bracket chamber is filled with lubricating oil.

16. The liquid chromatography high pressure pump according to claim 1, characterized in that: The code disc assembly comprises a large pulley, a belt, and a small pulley, the belt connects the large pulley and the small pulley, the small pulley is connected to the motor assembly, and the large pulley is connected to the push rod kit.

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