Combined plunger pump and filling device

Abstract

The invention provides a combined plunger pump and a filling device. The combined plunger pump comprises at least one plunger pump unit. The plunger pump unit comprises a pump body, two pistons and two pipeline assemblies. The pump body is provided with two cavities, the two cavities are oppositely arranged at intervals in the axial direction of the pump body, the two pistons are arranged in the two cavities respectively, and the two pistons can movably block the cavities where the pistons are located relative to the pump body respectively to form two containing cavities with variable volumes; each containing cavity is communicated with one pipeline assembly. The pipeline assembly comprises an input pipe, an output pipe, an input one-way valve and an output one-way valve. The input pipe and the output pipe are both communicated with the accommodating cavity; the input one-way valve is arranged on the input pipe and allows the medium to flow in; the output one-way valve is arranged on the output pipe and allows the medium to flow out; the pump body is used for reciprocating in the axial direction of the pump body so as to synchronously change the volumes of the two containing cavities according to opposite trends.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments, and in particular to a combined plunger pump and perfusion device. Background Art

[0002] Plunger pumps are widely used in the field of medical devices, usually as the basic structure of perfusion pumps to achieve simple perfusion functions. The advantages of plunger pumps are simple structure and easy manufacturing. The disadvantages of plunger pumps are that they cannot be continuously perfused, liquid cannot be output during refilling, and the input and output ports of the plunger pump are always connected. When the liquid at the input port of the plunger pump itself is under pressure, liquid will automatically flow through the pump body without control, which will cause the actual flow rate to be inconsistent with the expected flow rate. In addition, traditional plunger pumps use a method of fixed pump body and piston movement. In order to maintain the precise controllability of piston movement, a rigid piston rod is generally required. This will cause greater resistance when multiple channels of the plunger pump are used, which is not conducive to synchronization performance and power consumption control, making it difficult to achieve multi-channel coordinated input or output of the plunger pump. Summary of the invention

[0003] The object of the present invention is to provide a combined plunger pump and perfusion device to solve the problem that the existing plunger pump is difficult to achieve multi-channel coordination.

[0004] In order to solve the above technical problems, the present invention provides a combined plunger pump, which comprises: at least one plunger pump unit;

[0005] The plunger pump unit comprises a pump body, two pistons and two pipeline assemblies;

[0006] The pump body has two chambers, which are arranged in a spaced relationship along the axial direction of the pump body. The two pistons are respectively arranged in the two chambers, and the two pistons are respectively movably blocked in the chambers where they are located relative to the pump body to form two accommodating chambers with variable volumes; each accommodating chamber is respectively communicated with one of the pipeline assemblies;

[0007] The pipeline assembly includes an input pipe, an output pipe, an input check valve and an output check valve; the input pipe and the output pipe are both connected to the accommodating chamber; the input check valve is arranged on the input pipe to allow the medium to flow into the accommodating chamber; the output check valve is arranged on the output pipe to allow the medium to flow out of the accommodating chamber;

[0008] The pump body is used for reciprocating along its own axial direction to change the volumes of the two accommodating chambers synchronously and in opposite trends.

[0009] Optionally, the pipeline assembly further includes a pressure valve, which is disposed on the output pipe to allow the medium to flow at a pressure not less than a preset pressure.

[0010] Optionally, at least one of the input pipe and the output pipe passes through the piston to communicate with the accommodating chamber.

[0011] Optionally, the two pistons are coaxially arranged opposite to each other, and the cross-sectional areas of the two chambers along the axial direction of the pump body are the same.

[0012] Optionally, the material of the piston is a polymer material, the pump body includes an inner wall body for constituting the chamber, and the material of the inner wall body is glass, ceramic or stainless steel; the plunger pump unit also includes a piston rod connected to the piston, the piston rod is flexible and allows deformation in at least its own radial direction.

[0013] Optionally, the combined plunger pump includes more than two plunger pump units, the axes of all the plunger pump units are arranged in parallel, and the pump bodies of all the plunger pump units are interconnected or integrally formed.

[0014] Optionally, the cross-sectional areas of the chambers of at least two of the plunger pump units along the axial direction of the pump body are different or the same.

[0015] Optionally, the combined plunger pump further comprises a driving assembly, and the driving assembly is used to drive the pump bodies of all the plunger pump units to synchronously reciprocate axially.

[0016] Optionally, the driving assembly includes a motor, a gear and a rack; the gear is arranged at the output end of the motor, and the rack is arranged on any one of the pump bodies and meshes with the gear.

[0017] Optionally, the combined plunger pump also includes a base, the base has a limiting hole adapted to the cross-sectional contour shape of the pump body, the pump body is movably arranged in the limiting hole along its own axial direction, and the radial displacement is limited by the limiting hole; the plunger pump unit also includes a piston rod connected to the piston, and the end of the piston rod away from the piston is arranged on the base.

[0018] In order to solve the above technical problems, the present invention further provides a perfusion device, which includes the combined plunger pump as described above.

[0019] In summary, in the combined plunger pump and perfusion device provided by the present invention, the combined plunger pump includes at least one plunger pump unit; the plunger pump unit includes a pump body, two pistons and two pipeline assemblies; the pump body has two chambers, the two chambers are arranged relatively spaced along the axial direction of the pump body, the two pistons are respectively arranged in the two chambers, and the two pistons are respectively movably blocked in the chambers where they are located to form two variable-volume accommodating chambers; each of the accommodating chambers is respectively connected to one of the pipeline assemblies; the pipeline assembly includes an input pipe, an output pipe, an input check valve and an output check valve; the input pipe and the output pipe are both connected to the accommodating chamber; the input check valve is arranged on the input pipe to allow the medium to flow into the accommodating chamber; the output check valve is arranged on the output pipe to allow the medium to flow out of the accommodating chamber; the pump body is used to move back and forth along its own axial direction to change the volumes of the two accommodating chambers synchronously and in opposite trends.

[0020] With such a configuration, the alternating reciprocating and uninterrupted output of the two accommodating chambers is achieved based on the movement of the pump body, with less resistance, which is beneficial to synchronization performance and power consumption control, and is conducive to achieving multi-channel coordinated input or output. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0022] Figure 1 is an axial cross-sectional schematic diagram of a combined plunger pump according to an embodiment of the present invention;

[0023] Figure 2 is a partial schematic diagram of a combined plunger pump according to an embodiment of the present invention;

[0024] Figure 3 is a partial schematic diagram of a combined plunger pump according to an embodiment of the present invention;

[0025] Figure 4 It is a schematic axial cross-sectional view of a combined plunger pump according to another embodiment of the present invention.

[0026] In the attached figure:

[0027] 10- plunger pump unit; 110- pump body; 111- chamber; 112- accommodating chamber; 113- inner wall; 120- piston; 121- piston rod; 131- input pipe; 132- output pipe; 133- input one-way valve; 134- output one-way valve; 135- pressure valve; 136- input main pipe; 137- output main pipe; 20- base; 210- limiting hole; 30- driving assembly; 310- gear; 320- rack. DETAILED DESCRIPTION

[0028] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0029] As used in the present invention, the singular forms "a", "an", "one" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only endpoints. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or one side of another element, unless the content clearly indicates otherwise. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as shown in the figures, with the upward or upper direction toward the top of the corresponding figure, and the downward or lower direction toward the bottom of the corresponding figure.

[0030] The purpose of the present invention is to provide a combined plunger pump and a perfusion device to solve the problem that the existing plunger pump is difficult to achieve multi-channel coordination.

[0031] Please refer to Figures 1 to 3 The embodiment of the present invention provides a combined plunger pump, which includes at least one plunger pump unit 10; the plunger pump unit 10 includes a pump body 110, two pistons 120 and two pipeline assemblies; the pump body 110 has two chambers 111, and the two chambers 111 are arranged along the axial direction of the pump body 110 ( Figure 1The two pistons 120 are arranged in a relative spacing with respect to the two chambers 111, and the two pistons 120 are respectively arranged in the two chambers 111, and the two pistons 120 are respectively blocked in the chambers where they are located relative to the pump body 110 to form two variable-volume accommodating chambers 112; each of the accommodating chambers 112 is communicated with one of the pipeline components; the pipeline component includes an input pipe 131, an output pipe 132, an input check valve 133 and an output check valve 134; the input pipe 131 and the output pipe 132 are both communicated with the accommodating chamber 112; the input check valve 133 is arranged on the input pipe 131 to allow the medium to flow into the accommodating chamber 112; the output check valve 134 is arranged on the output pipe 132 to allow the medium to flow out of the accommodating chamber 112; the pump body 110 is used to reciprocate along its own axial direction to change the volumes of the two accommodating chambers 112 synchronously and in opposite trends.

[0032] It should be noted that the two chambers 111 are arranged relatively spaced apart along the axial direction of the pump body 110, which means that the two chambers 111 are arranged along the axial direction of the pump body 110, and the two can be coaxial or non-coaxial and parallel to each other. It can be understood that one end of the chamber 111 is a closed end and the other end is an open end, which is used for the piston 120 to be plugged into, thereby forming an accommodating chamber 112. Since the two chambers 111 can be coaxial or parallel, the two pistons 120 can be coaxial or parallel in a matching manner. The cross-sectional profile shape of the piston 120 along the axial direction of the pump body 110 is compatible with the cross-sectional profile shape of the chamber 111 along the axial direction of the pump body 110, and the cross-sectional profile shape of the piston 120 and the cross-sectional profile of the chamber 111 are preferably both circular. Furthermore, the piston 120 can seal and block the chamber 111 well, so that the accommodating chamber 112 constitutes a relatively closed space, and the accommodating chamber 112 is isolated from the outside except for being connected with the input pipe 131 and the output pipe 132. In this way, when the pump body 110 moves along its own axial direction, the volume of the accommodating chamber 112 is driven to change, and based on the setting of the input check valve 133 and the output check valve 134, the medium can be driven to flow in one direction to achieve pumping.

[0033] In addition, the opposite trend of the volume change of the accommodating chamber 112 here means that if the volume of one of the accommodating chambers 112 increases, the volume of the other accommodating chamber 112 decreases. Since the plunger pump unit 10 includes two accommodating chambers 112, when the pump body 110 reciprocates along its own axial direction, the two accommodating chambers 112 can be output alternately in sequence, so continuous output can be achieved. In particular, when the pump body 110 reciprocates along its own axial direction, the two accommodating chambers 112 change the volume synchronously, which means that the two accommodating chambers 112 produce volume changes at the same time, but it is not limited to the absolute value of the volume change of the two chambers must be the same. In some embodiments, the absolute value of the volume change of the two chambers may be the same, and in other embodiments, it may be different. Preferably, the two pistons 120 are coaxially arranged relative to each other, and the cross-sectional area of ​​the two chambers 111 along the axial direction of the pump body 110 is the same, so that the absolute value of the volume change of the two chambers 112 is the same.

[0034] For further information, please refer to Figure 2 , the input pipes 131 of the two pipeline assemblies are connected to the input trunk pipe 136, and the output pipes 132 of the two pipeline assemblies are connected to the output trunk pipe 137. In an application scenario, the input trunk pipe 136 can be connected to an external infusion bag, and the perfusion liquid is divided through the input trunk pipe 136 and enters the two input pipes 131 respectively, and then driven by the reciprocating movement of the pump body 110, it is squeezed out to the two output pipes 132 through the two accommodating chambers 112 in turn, and flows out from the output trunk pipe 137, for example, it can be used to flow to a target object such as a catheter pump to achieve uninterrupted continuous perfusion of the target object. It should be noted that the combined plunger pump provided in this embodiment is not limited to being used only for pumping perfusion liquid, and it can also be used to pump other media, including liquids and / or gases, which is not limited in this embodiment.

[0035] Preferably, the pipeline assembly also includes a pressure valve 135, which is arranged on the output pipe 132 to allow the medium to circulate when the pressure is not less than the preset pressure. It can be understood that, in an ideal state, when there is no pressure difference between the input main pipe 136 and the output main pipe 137 of the pumped medium itself, the pumping amount of the medium can be accurately controlled by controlling the movement of the pump body 110. However, in many application scenarios, there is a pressure difference in the pumped medium itself, for example, the external infusion bag is at a high position relative to the target object such as the catheter pump, then the height difference between the two at this time causes the medium itself to have a pressure difference. Since the input pipe 131 is always connected to the output pipe 132 through the accommodating cavity 112, the pressure difference of the medium itself will cause the medium to flow uncontrolled, thereby causing the actual flow rate to be greater than the set expected flow rate, affecting the flow accuracy.

[0036] In this embodiment, the pressure valve 135 is set so that the medium can pass only when the pressure is not less than the preset pressure. The preset pressure can be set as needed. In this way, the interference factor of the medium's own pressure can be eliminated, the self-flow phenomenon of the medium can be blocked, and its influence on the accuracy can be eliminated. The pressure valve 135 can be, for example, a pressure valve plate or other structure.

[0037] Further, the combined plunger pump also includes a base 20, and the plunger pump unit 10 also includes a piston rod 121 connected to the piston 120, and one end of the piston rod 121 away from the piston 120 is arranged on the base 20. The piston rod 121 is preferably arranged along the axial direction of the pump body 110, one end of which is fixedly arranged on the base 20, and the other end is connected to the piston 120. The pump body 110 is movably arranged on the base 20 along its own axial direction. The existing plunger pump often configures the pump body 110 to be fixed and drives the piston 120 to move to achieve pumping. However, when such a structure is applied to a combined plunger pump such as the present embodiment, it is necessary to keep the two pistons 120 linked, so that the piston rod 121 needs to have a certain rigidity. In addition, the two piston rods 121 need to be fixedly connected, and the connection structure of the piston rod 121 cannot enter the chamber 111 of the pump body 110, so it is necessary to further lengthen the piston rod 121, resulting in a larger volume of the entire structure.

[0038] In particular, in a combined plunger pump used in a multi-channel pumping scenario, the combined plunger pump needs to include more than two plunger pump units 10. At this time, in order to maintain synchronization, the multiple piston rods 121 of different plunger pump units 10 require higher processing and assembly accuracy, and the concentricity between the piston rod 121 and the chamber 111 is limited by the assembly accuracy, and there will be a certain error, causing additional friction resistance. Any slight eccentricity or inaccurate processing and assembly of any piston rod 121 will cause the driving power consumption of the entire combined plunger pump to increase significantly, and the more piston rods 121 and chambers 111 there are, the greater the friction resistance.

[0039] Based on the above analysis, it can be known that the structure in which the pump body 110 is fixed and the piston 120 moves is not suitable for a combined plunger pump, especially a multi-channel combined plunger pump including more than two plunger pump units 10. The structure in which the pump body 110 is fixed and the piston 120 moves is not conducive to reducing driving resistance, reducing volume, or synchronization, which makes it difficult to achieve multi-channel coordinated input or output.

[0040] To this end, the plunger pump unit 10 of the combined plunger pump provided in this embodiment configures the piston 120 to be fixed, and by moving the pump body 110 along its own axial direction, the stiffness requirement on the piston rod 121 is eliminated, and the precision requirement on the processing and assembly of the piston rod 121 is reduced, which is beneficial to reducing driving resistance, reducing volume, and facilitating synchronization, and facilitating the realization of multi-channel coordinated input or output.

[0041] Please refer to Figure 2 Preferably, the combined plunger pump includes more than two plunger pump units 10, the axes of all the plunger pump units 10 are arranged in parallel, and the pump bodies 110 of all the plunger pump units 10 are interconnected or integrally formed. More than two plunger pump units 10 can form more than two channels, each channel can flow different media respectively, and based on the fact that the pump bodies 110 of all the plunger pump units 10 are interconnected or integrally formed, the pumping of all the plunger pump units 10 is also synchronized, so that multi-channel coordinated input or output can be achieved, and the flow rates of input or output of different channels are mutually coordinated and constant in proportion.

[0042] The different channels of this multi-channel combined plunger pump can perform synchronous perfusion function, synchronous suction function, or synchronous perfusion and suction function, the only difference is whether the connection position between the target object and its plunger pump unit 10 is the input tube 131 or the output tube 132. If the target object is connected to the output tube 132, the plunger pump unit 10 is used to perfuse it, and if the target object is connected to the input tube 131, the plunger pump unit 10 is used to suction it. In an application scenario, when the combined plunger pump is applied to a percutaneous catheter blood pump, it includes two channels. The two channels are respectively connected to two different points of the catheter of the percutaneous catheter blood pump, one of which is used to inject lubricating fluid into the catheter, and the other channel is used to suck out the lubricating fluid in the catheter. Correspondingly, the combined plunger pump includes two plunger pump units 10.

[0043] Optionally, the cross-sectional areas of the chambers 111 of at least two of the plunger pump units 10 along the axial direction of the pump body 110 are different or the same. In some application scenarios, the combined plunger pump includes two plunger pump units 10, the target object is a catheter pump, one plunger pump unit 10 is used for perfusion, and the other plunger pump unit 10 is used for suction. Since there is a gap in the distal rotating part of the catheter pump, part of the perfusion liquid will enter the human body from the distal end, so the liquid volume injected into the channel is always greater than the liquid volume of the suction channel. Based on this, the cross-sectional areas of the chambers 111 of the two plunger pump units 10 along the axial direction of the pump body 110 can be set to be different. For example, the cross-sectional area of ​​the plunger pump unit 10 used for perfusion is larger, and the cross-sectional area of ​​the plunger pump unit 10 used for suction is smaller. In other application scenarios, for example, if two channels need to be perfused at the same time, then the cross-sectional areas of the chambers 111 of the two plunger pump units 10 along the axial direction of the pump body 110 can be the same.

[0044] Since the pump bodies 110 of the two plunger pump units 10 are connected or integrally arranged, the distances moved by the four chambers 111 in the direction of linear motion are always the same, and the only factor affecting the volume of the accommodating chamber 112 inside the pump body 110 is the cross-sectional area of ​​the chamber 111. It is sufficient to configure the cross-sectional area of ​​the plunger pump unit 10 used for infusion and the cross-sectional area of ​​the plunger pump unit 10 used for suction to follow a certain proportional relationship. Preferably, the cross-section of the chamber 111 is circular, and at this time, the diameter of the chamber 111 of the plunger pump unit 10 used for infusion is greater than the diameter of the chamber 111 of the plunger pump unit 10 used for suction.

[0045] Optional, please refer to Figure 3 , the base 20 has a limiting hole 210 that is compatible with the cross-sectional profile shape of the pump body 110. The pump body 110 is movably arranged in the limiting hole 210 along its own axial direction, and the displacement in the radial direction is limited by the limiting hole 210. The setting of the limiting hole 210 effectively limits the pump body 110 to move only along its own axial direction, reduces the deflection of the pump body 110, and is conducive to reducing the driving resistance and driving power consumption. It should be understood that the shape of the limiting hole 210 here is compatible with the cross-sectional profile shape of the pump body 110. For a combined plunger pump including more than two plunger pump units 10, all of its pump bodies 110 are interconnected or integrated. At this time, the limiting hole 210 also needs to be adaptively arranged to meet the penetration of all pump bodies 110.

[0046] Optionally, the combined plunger pump further includes a driving assembly 30, which is used to drive the pump bodies 110 of all the plunger pump units 10 to synchronously reciprocate along the axial direction. In an alternative exemplary embodiment, the driving assembly 30 includes a motor (not shown), a gear 310 and a rack 320; the gear 310 is arranged at the output end of the motor, and the rack 320 is arranged at any of the pump bodies 110 and meshes with the gear 320. The rack 320 is preferably arranged along the axial direction of the pump body 110. The motor can be fixed on the base 20, and its output shaft is preferably perpendicular to the axial direction of the pump body 110, so that the gear 310 can mesh with the rack 320. The gear 310 can only perform rotational motion relative to the base 20, and the rack 320 can only perform linear reciprocating motion relative to the base 20 along the axial direction of the pump body 110, and the cavity 111 in the pump body is always kept concentric and coaxial with the piston 120 during the movement. In order to reduce friction, the material of the base 20 can be selected from materials with low friction coefficient or self-lubricating materials, such as PTFE, etc. The material of the gear 310 and the rack 320 can be selected from polymer materials with high hardness, such as POM, PEEK, etc., which can ensure the strength and service life of the gear 310 and the rack 320 on the one hand, and can be easily processed and have lower cost than metal materials on the other hand.

[0047] Preferably, the material of the piston 120 is a polymer material, and the pump body 110 includes an inner wall body 113 for constituting the chamber 111, and the material of the inner wall body 113 is glass, ceramic or stainless steel. It can be understood that the inner wall body 113 of the pump body 110 and the piston 120 are in a sliding seal fit, that is, the piston 120 can achieve axial reciprocating movement in the chamber 111, and the medium in the chamber 111 will not leak from the fit gap when it is less than a certain specific pressure value. Here, two requirements are put forward for the fit between the piston 120 and the inner wall body 113, that is, good sealing and smooth sliding are required. For the realization of this sliding seal, there are usually two options. One way is to select an inner wall body 113 with good rigidity and not easy to deform, and match a piston 120 with a certain elastic deformation ability (such as rubber or silicone, etc.). At this time, the size of the piston 120 is usually slightly larger than the size of the inner wall body 113, and the sealing is achieved by interference fit. Its principle is similar to that of a disposable medical syringe. However, the disadvantage of this method is that the piston 120 needs to be lubricated with lubricating oil. When the piston 120 runs for a long time, the lubrication is easy to fail, and the movement resistance of the piston 120 will become larger. Another method is that the inner wall 113 and the piston 120 are both made of rigid materials that are not easy to deform, such as stainless steel. The disadvantage of this method is that the processing accuracy of the inner wall 113 and the piston 120 is extremely high, and long-term operation will cause wear and produce debris.

[0048] Based on the above analysis, it can be known that the conventional cooperation between the piston 120 and the inner wall body 113 does not meet the requirements of this embodiment. Based on this, this embodiment adopts an inner wall body 113 with higher hardness and stronger rigidity and a piston 120 with certain elasticity and hardness. The material constituting the inner wall body 113 may be selected from but not limited to materials such as high borosilicate glass, silica glass, ceramics or stainless steel, preferably glass, because its surface roughness can be made very small, thereby ensuring the smoothness of the reciprocating motion of the piston 120, and the glass is relatively stable in nature and is not easy to produce adverse reactions with the internal medium. Of course, in other embodiments, the pump body 110 can be composed of materials such as high borosilicate glass, silica glass, ceramics or stainless steel as a whole.

[0049] The piston 120 is made of polymer materials, such as PTFE, PP, PE, etc. Polymer materials are harder than rubber and silicone, and do not require too much dimensional interference to achieve sealing; at the same time, polymer materials have weak rigidity and certain elastic deformation ability, which reduces the structural requirements for the size of the piston 120 and does not require precise matching like two rigid materials. The combination of the glass pump body 110 and the polymer piston 120 has the advantages of smooth sliding, good sealing, no wear debris, and stable properties.

[0050] Preferably, the piston rod 121 is flexible and allows deformation in at least its radial direction. Since each plunger pump unit 10 includes two chambers 111 and two pistons 120, and the two pistons 120 are connected to the base 20 through two piston rods 121, respectively, the concentricity between the piston 120, the piston rod 121 and the chamber 111 is limited by the assembly accuracy, and there will be a certain error, which is easy to cause additional friction resistance, and the more pistons 120 and chambers 111 there are, the greater the resistance. In order to reduce the error caused by assembly, the piston rod 121 can choose to use a material with a certain flexibility or elasticity, so that it can support the piston 120 to reciprocate in the chamber 111, and at the same time produce a small offset deformation in the radial direction, automatically adjust the center position of the piston 120 and the chamber 111, and minimize the friction resistance caused by processing and assembly errors.

[0051] Optionally, at least one of the input pipe 131 and the output pipe 132 passes through the piston 120 and is connected to the accommodating chamber 112. Figure 1 In the illustrated example, the input pipe 131 passes through the piston 120 and is connected to the accommodating chamber 112, while the output pipe 132 directly passes through the pump body 110 and is connected to the accommodating chamber 112. Suitably, the input pipe 131 is also provided through the piston rod 121. Since the pump body 110 needs to move back and forth, the input pipe 131 or the output pipe 132 directly connected thereto will also move with it, which is not conducive to long-term use. However, by arranging at least one of the input pipe 131 and the output pipe 132 in the piston 120, the internal space of the piston 120 and the piston rod 121 can be utilized, and the configuration is fixed, which is conducive to improving the service life and also conducive to reducing the space.

[0052] Please refer to Figure 4 In other embodiments, the input pipe 131 and the output pipe 132 can simultaneously pass through the piston 120 and connect to the accommodating chamber 112. Suitably, the input pipe 131 and the output pipe 132 are also passed through the piston rod 121. That is, at this time, the input pipe 131 and the output pipe 132 are both configured as fixed, which is more conducive to improving the service life and reducing the space.

[0053] Based on the combined plunger pump as described above, an embodiment of the present invention further provides an infusion device, which includes the combined plunger pump as described above. The infusion device can be used in instruments such as catheter pumps. Other structures and principles of the infusion device can refer to the prior art and will not be described in detail here.

[0054] In summary, in the combined plunger pump and perfusion device provided by the present invention, the combined plunger pump includes at least one plunger pump unit; the plunger pump unit includes a pump body, two pistons and two pipeline assemblies; the pump body has two chambers, the two chambers are arranged relatively spaced along the axial direction of the pump body, the two pistons are respectively arranged in the two chambers, and the two pistons are respectively movably blocked in the chambers where they are located relative to the pump body to form two variable-volume accommodating chambers; each of the accommodating chambers is respectively connected to one of the pipeline assemblies; the pipeline assembly includes an input pipe, an output pipe, an input check valve and an output check valve; the input pipe and the output pipe are both connected to the accommodating chamber; the input check valve is arranged on the input pipe to allow the medium to flow into the accommodating chamber; the output check valve is arranged on the output pipe to allow the medium to flow out of the accommodating chamber; the pump body is used to move back and forth along its own axial direction to change the volumes of the two accommodating chambers synchronously and in opposite trends. With such a configuration, the alternating reciprocating and uninterrupted output of the two accommodating chambers is achieved based on the movement of the pump body, with less resistance, which is beneficial to synchronization performance and power consumption control, and is conducive to achieving multi-channel coordinated input or output.

[0055] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the protection scope of the present invention.

Claims

1. A combined plunger pump, characterized in that: comprising at least one plunger pump unit; The plunger pump unit comprises a pump body, two pistons and two pipeline assemblies; The pump body has two chambers, which are arranged in a spaced relationship along the axial direction of the pump body. The two pistons are respectively arranged in the two chambers, and the two pistons are respectively movably blocked in the chambers where they are located relative to the pump body to form two accommodating chambers with variable volumes; each accommodating chamber is respectively communicated with one of the pipeline assemblies; The pipeline assembly includes an input pipe, an output pipe, an input check valve and an output check valve; the input pipe and the output pipe are both connected to the accommodating chamber; the input check valve is arranged on the input pipe to allow the medium to flow into the accommodating chamber; the output check valve is arranged on the output pipe to allow the medium to flow out of the accommodating chamber; The pump body is used for reciprocating along its own axial direction to change the volumes of the two accommodating chambers synchronously and in opposite trends.

2. The combined plunger pump according to claim 1, characterized in that: The pipeline assembly further includes a pressure valve, which is disposed on the output pipe to allow the medium to flow when the pressure is not less than a preset pressure.

3. The combined plunger pump according to claim 1, characterized in that: At least one of the input pipe and the output pipe passes through the piston to communicate with the accommodating chamber.

4. The combined plunger pump according to claim 1, characterized in that: The two pistons are coaxially arranged opposite to each other, and the cross-sectional areas of the two chambers along the axial direction of the pump body are the same.

5. The combined plunger pump according to claim 1, characterized in that: The piston is made of polymer material, the pump body includes an inner wall body for constituting the chamber, and the material of the inner wall body is glass, ceramic or stainless steel; the plunger pump unit also includes a piston rod connected to the piston, and the piston rod is flexible and allows deformation in at least its own radial direction.

6. The combined plunger pump according to claim 1, characterized in that: The combined plunger pump comprises more than two plunger pump units, the axes of all the plunger pump units are arranged in parallel, and the pump bodies of all the plunger pump units are interconnected or integrally formed.

7. The combined plunger pump according to claim 6, characterized in that: The cross-sectional areas of the chambers of at least two of the plunger pump units along the axial direction of the pump body are different or the same.

8. The combined plunger pump according to claim 6, characterized in that: The combined plunger pump further comprises a driving assembly, which is used to drive the pump bodies of all the plunger pump units to synchronously reciprocate in the axial direction.

9. The combined plunger pump according to claim 8, characterized in that: The driving assembly includes a motor, a gear and a rack; the gear is arranged at the output end of the motor, and the rack is arranged on any one of the pump bodies and meshes with the gear.

10. The combined plunger pump according to claim 1, characterized in that: The combined plunger pump also includes a base, which has a limiting hole that is compatible with the cross-sectional contour shape of the pump body. The pump body is movably arranged in the limiting hole along its own axial direction and is restricted in radial displacement by the limiting hole; the plunger pump unit also includes a piston rod connected to the piston, and the end of the piston rod away from the piston is arranged on the base.

11. A perfusion device, characterized in that: It comprises a combined plunger pump according to any one of claims 1 to 10.

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