Hydraulic transmission micro-injection pump

Abstract

The utility model discloses a hydraulic transmission micro-injection pump which comprises a motor driving part, a mechanical transmission part, a hydraulic transmission part, a valve body control part, a kinetic energy transmission medium storage cavity and a liquid medicine assembly part, the hydraulic transmission part adopts two hydraulic chambers with different chamber body diameters, and the injection precision of the micro-injection pump can be improved through conversion between the same volume and different injection distances. The two-stage hydraulic chamber, the lead screw stepping motor and other mechanisms are used in a combined mode, the power direction can be changed, the internal structure of the injection pump is more reasonable and compact, and the size is smaller.

Description

Technical Field

[0001] The utility model belongs to the field of medical technology. Specifically, it relates to a hydraulic transmission device for a fluid infusion device and a fluid infusion device with the hydraulic transmission device. More specifically, it belongs to a hydraulic transmission micro-injection pump. Background Art

[0002] A micro-injection pump is a device that can precisely control the liquid flow rate. It mainly consists of an infusion tube, a roller, a stepper motor, a control circuit, etc. Micro-injection pumps have been widely used in the medical field, laboratories, industrial production and other fields. As an intelligent injection device, the micro-injection pump has the function of micro, uniform, continuous and precise pumping of drugs into the human body, and can adjust the drug delivery speed and drug dose as needed; the drug solution is transmitted smoothly without pulsation, maintaining an ideal and stable blood drug concentration in the patient's body to meet the treatment requirements of precise drug delivery; in addition, it is convenient, fast and efficient to operate.

[0003] So far, there are more than 40 manufacturers of approved and registered micro-injection pumps, such as the German Braun micro-injection pump, the injection pumps of Dekka Company, BD Company, Smith ADS Company, Sapphire Company, Fresenius Kabi Company, Nipro Company, Core Medical Company, etc. abroad; well-known domestic injection pump manufacturers such as the injection pumps of Mectron Company, the ZNB series of Beijing Keweifenggao Company, the TCI-II of Guangxi Weili Fangzhou Injection Pump, and the WZS series of Zhejiang University; among them, the WZS series has the largest market share and is commonly known as the Zhejiang University pump in the industry.

[0004] Comparing domestic and imported injection pumps, their principles are similar. The schematic diagram is as shown in the appendix Figure 1 Specifically, the micro-injection pump is composed of a stepper motor and its driver, a lead screw and a bracket, etc. It has a reciprocating lead screw and a nut, so it is also called a lead screw pump. The nut is connected to the piston of the syringe, and the syringe contains the drug solution. During operation, the single-chip microcomputer system issues a control pulse to start the rotation of the stepper motor, and the stepper motor drives the lead screw to convert the rotational motion into a linear motion, pushing the drug solution in the syringe into the human body through the pipeline. By setting the rotation speed of the screw, the propulsion speed of the syringe plunger can be adjusted, so as to adjust the given drug dose.

[0005] The above-mentioned syringe pump has certain disadvantages. Conventional syringe pumps use a stepper motor to drive a lead screw and a slider, and the movement of the slider directly pushes the syringe piston to move and administer drugs outward. However, when using a large-capacity syringe to achieve micro-intermittent injection drug delivery, due to the principle of the stepper motor itself, since the number of turns of the lead screw rotation is small in this way, mechanical errors and hardware errors will be amplified, and the accuracy of single-dose micro-drug delivery will be low. Such syringe pumps with mechanical transmission cannot meet the required conditions of single-dose micro-precision (5-10 μL / min, 1 min / each time, intermittent drug delivery, 10 μL ± 5%) when using syringes of 2 mL or more for drug delivery in the nasal-brain delivery system. At the same time, the syringe pump does not support 1 mL syringes.

[0006] There is a patent report that CN106267464A adopts a syringe pump with hydraulic transmission. However, this type of syringe pump can selectively determine the flow rate of the infusion fluid through a flow-limiting device arranged in the middle of the hydraulic chamber, but still does not solve the problem of injection accuracy.

[0007] The blood-brain barrier (BBB) is the most important bottleneck for drugs to play a therapeutic role in central diseases. Due to the existence of the blood-brain barrier, existing drug delivery routes such as oral, intravenous, intramuscular, and subcutaneous cannot effectively deliver drugs to the central nervous system (CNS). Since drugs cannot effectively cross the blood-brain barrier, they cannot play a therapeutic role in brain diseases. In addition, as the drug dosage increases, systemic side effects also increase.

[0008] Drug delivery through the nasal mucosa has been considered a drug delivery method that can be rapidly and efficiently absorbed. There are many fine villi on the nasal mucosa cells, so the effective area of drug absorption is greatly increased. Drugs can bypass the blood-brain barrier and directly enter the brain through the mucosa of the olfactory region in the upper nasal meatus to exert their efficacy. Therefore, the nasal-brain delivery system is increasingly attracting the attention of pharmaceutical R & D enterprises. For drugs to directly enter the brain through the nasal mucosa, the dosage needs to be accurate to meet the safety requirements. Nasal-brain delivery is different from injection drug delivery, which can bring drugs into the human body from the injection site through blood circulation. The nasal-brain delivery system does not pass through blood circulation. It is a treatment method that transports drugs to the nasal mucosa, uses the nasal mucosa to absorb drugs and bypasses the blood-brain barrier to reach the brain directly. Moreover, the absorption of the nasal mucosa is relatively slow, and it requires very small doses to be administered slowly and multiple times. Excessive single-dose administration or inaccurate dosage will cause the drug to flow into the lungs and damage other organs.

[0009] Currently, commercially available injection pumps or insulin pumps cannot meet the clinical use requirements of the nasal-brain delivery system. The syringes used in commercially available injection pumps are all larger than 1 mL. If larger syringes are used, the single-injection accuracy is insufficient and cannot meet the requirement of 5 - 10 μL / min. Insulin pumps belong to class III medical devices. Although the accuracy can meet the requirements, the price is too high, and patients are difficult to afford the price, resulting in difficulty in clinical application. Therefore, there is an urgent need to develop an injection pump with high injection accuracy, smaller volume, less energy loss, and low price to meet the clinical use requirements when administering nasal-brain delivery preparations. Summary of the Invention

[0010] To solve the above problems, the present utility model provides a hydraulic transmission micro-injection pump, which includes a motor drive part, a mechanical transmission part, and also includes a hydraulic transmission part, a valve body control part, a kinetic energy transmission medium storage chamber, and a liquid medicine assembly part;

[0011] The hydraulic transmission part includes a first hydraulic chamber, a first push rod arranged in the first hydraulic chamber, and a piston A that can closely cooperate with the first push rod and the first hydraulic chamber; a second hydraulic chamber, a second push rod arranged in the second hydraulic chamber, and a piston B that can closely cooperate with the second push rod and the second hydraulic chamber; one end of the first push rod is connected to the push block of the stepping motor; the first hydraulic chamber and the second hydraulic chamber are filled with a kinetic energy transmission medium; the first hydraulic chamber has a smaller chamber body diameter and a longer first push rod, and the second hydraulic chamber has a larger chamber body diameter; more preferably, the chamber body diameter of the first hydraulic chamber is smaller than that of the second hydraulic chamber;

[0012] The kinetic energy transmission medium storage chamber includes two or more chambers and also includes a waterproof and breathable valve;

[0013] The valve body control part includes a liquid inlet pipeline, a return oil pipeline, and a valve body that can switch the liquid flow direction;

[0014] The liquid medicine assembly part includes a syringe, and optionally also includes a syringe bracket. The syringe includes a liquid medicine cylinder and an injection push rod, and the injection push rod is connected to the second push rod of the second hydraulic chamber for injecting the liquid medicine; the syringe bracket is installed on the injection pump for placing the syringe.

[0015] Preferably, the motor drive part includes: a stepping motor and a speed reducer. The stepping motor has a motor shaft, and a gear is fixedly arranged on the motor shaft; the speed reducer includes two or more gears of different sizes, and the gear on the motor shaft meshes with the gears of the speed reducer;

[0016] And / or, the mechanical transmission part includes: a push block, a bearing, a guide rail, and a lead screw arranged on the bearing; wherein the push block can move on the lead screw.

[0017] As a preferred embodiment, the kinetic energy transmission medium is an incompressible liquid, and further preferably, it is hydraulic oil, water or a mixture of the two.

[0018] As a preferred embodiment, the first hydraulic chamber comprises a rigid cavity and a sealed piston A. On one side of the piston A is a first push rod, and on the other side of the piston is the kinetic energy transmission medium.

[0019] Preferably, the second hydraulic chamber comprises a rigid cavity and a sealed piston B. There is flowing kinetic energy transmission medium on both sides of the piston B, and the reciprocating movement of the piston B is controlled by the increase and decrease of the kinetic energy transmission medium.

[0020] Preferably, the valve body with switchable liquid flow direction includes a pressure relief valve, a one-way valve and a liquid reversing valve; the liquid inlet pipeline is used to push the kinetic energy transmission medium with pressure in the first hydraulic chamber to the second hydraulic chamber, and the oil return pipeline is used to send the kinetic energy transmission medium back to the kinetic energy transmission medium storage cavity.

[0021] Preferably, the hydraulic transmission micro-injection pump of the present application is also provided with a blockage alarm device, and the blockage alarm device is installed outside the second hydraulic chamber.

[0022] Preferably, the hydraulic transmission micro-injection pump of the present invention also includes a pressure relief valve, and the pressure relief valve is installed on the opposite side of the piston B that pushes the drug into the liquid in the second hydraulic chamber.

[0023] Preferably, the hydraulic transmission micro-injection pump of the present invention also includes a one-way valve installed at the outlet end of the first hydraulic chamber, which is used to prevent liquid backflow and lock the push rod.

[0024] Preferably, the waterproof and breathable valve is installed at the top of the kinetic energy transmission medium storage cavity and is connected to the atmosphere.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention utilizes the principle that a smaller diameter of the hydraulic chamber and a smaller diameter cavity for injection have higher precision, converts the kinetic energy transmission medium with higher precision for injection into a cavity with a larger inner diameter, and then the piston in the larger cavity pushes the syringe with a larger inner diameter, so that the injection of the syringe with a larger inner diameter has the precision of the syringe with a smaller inner diameter. By setting two hydraulic chambers with different sizes, the injection precision of the traditional injection pump can be increased from 10% to 5%.

[0027] 2. The present invention can change the power direction by connecting the two-stage hydraulic chamber and the lead screw stepping motor and other mechanisms, making the internal structure of the injection pump more reasonable and the volume smaller.

[0028] 3. Different from the traditional injection pump where the pressure sensor is installed at the handle end of the syringe, the pressure sensor of the present utility model is installed inside the hydraulic cavity, making the sensor more sensitive and the blockage detection conduction faster.

[0029] 4. The present utility model has a closed hydraulic chamber and a pressure self-check function during transmission, and can more accurately detect the volume reduction in the oil liquid and pipeline during drug infusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objects, and advantages of the present utility model will become more apparent:

[0031] Figure 1 is a schematic diagram of the principle of a mechanical transmission micro-injection pump in the prior art;

[0032] Figure 2 is a schematic structural diagram of the hydraulic transmission micro-injection pump of the present utility model;

[0033] Figure 3 is a partial enlarged view of the hydraulic transmission micro-injection pump of the present utility model;

[0034] Figure 4 is a three-dimensional partial view of the hydraulic transmission micro-injection pump of the present utility model;

[0035] Figure 5 is a right three-dimensional partial view of the hydraulic transmission micro-injection pump of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions, and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings. It should be noted that the present utility model is not limited to the component structures and / or arrangements shown in the drawings, and various different combinations can be made to the various embodiments of the present utility model without departing from the essence of the present utility model. These all fall within the protection scope of the present utility model.

[0037] Therefore, the detailed description of the embodiments of the present utility model provided in the following drawings is not intended to limit the scope of the present utility model to be protected, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present utility model without creative efforts fall within the protection scope of the present utility model.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0039] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the products of the present utility model are customarily placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0040] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0041] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0042] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0043] Term Explanation:

[0044] Incompressible liquid, a liquid with certain fluidity and viscosity, whose liquid approximately has incompressibility or very small compressibility;

[0045] Such as Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown in

[0046] The mechanical transmission part includes: a push block 2-1, bearings, guide rails, and a lead screw 2-2 arranged on the bearings; wherein the push block 2-1 can move on the lead screw 2-2;

[0047] The hydraulic transmission part includes: a first hydraulic chamber 3-1, a first push rod 3-2 arranged in the first hydraulic chamber, and a piston A (not shown in the figure) that can be closely fitted with the first push rod 3-2 and the first hydraulic chamber 3-1; a second hydraulic chamber 3-3, a second push rod 3-4 arranged in the second hydraulic chamber 3-3, and a piston B (not shown in the figure) that can be closely fitted with the second push rod 3-4 and the second hydraulic chamber 3-3; one end of the first push rod 3-2 is connected to the push block 2-1 of the stepping motor 1-1; kinetic energy transmission media are filled in the first hydraulic chamber 3-1 and the second hydraulic chamber 3-3;

[0048] The kinetic energy transmission medium storage chamber includes: two or more chambers arranged inside, and also includes a waterproof and breathable valve 5-1.

[0049] The valve body control part includes: a liquid inlet pipeline 4-1, a liquid return pipeline 4-2, and a valve body that can switch the liquid flow direction;

[0050] The liquid medicine assembly part includes a syringe and a syringe bracket 6-2. The syringe includes a liquid medicine cylinder 6-11 and an injection push rod 6-12. The injection push rod 6-12 is connected to the second push rod 3-4 of the second hydraulic chamber 3-3 and is used for injecting liquid medicine; the syringe bracket 6-2 is installed on the injection pump and is used for placing the syringe.

[0051] In a specific embodiment of the present invention, the first hydraulic chamber 3-1 has a smaller chamber body diameter, a longer first push rod 3-2, and a longer chamber body length, and the second hydraulic chamber 3-3 has a larger chamber body diameter. Here, it is necessary to ensure that the chamber body diameter of the first hydraulic 3-1 is smaller than that of the second hydraulic chamber 3-3 to improve the accuracy. Those skilled in the art can set the chamber body diameter ratio of the first hydraulic chamber and the second hydraulic chamber according to the volume size requirement of the injection pump. The smaller the chamber body diameter ratio of the first hydraulic chamber 3-1 to the second hydraulic chamber 3-3, the higher the accuracy.

[0052] In a specific embodiment of the present invention, the kinetic energy transmission medium is an incompressible liquid. Exemplarily, the incompressible liquid is oil, water, or a mixture of the two.

[0053] In yet another specific embodiment of the present utility model, the first hydraulic chamber 3-1 comprises a rigid cavity and a sealed piston A. On one side of the piston A is a first push rod, and on the other side is a kinetic energy transmission medium. During operation, the single-chip microcomputer system issues a control pulse to start the rotation of the stepping motor 1-1. The rotation of the stepping motor 1-1 controls the rotation of the lead screw 2-2, and then the lead screw 2-2 controls the reciprocating motion of the push block 2-1 to further control the reciprocating motion of the piston A.

[0054] In yet another specific embodiment of the present utility model, the second hydraulic chamber 3-3 comprises a rigid cavity and a sealed piston B. There is flowing kinetic energy transmission medium on both sides of the piston B, and the reciprocating motion of the piston is controlled by the increase and decrease of the kinetic energy transmission medium.

[0055] In yet another specific embodiment of the present utility model, the valve body capable of switching the liquid flow direction includes a pressure relief valve 4-3, a one-way valve 4-4, and a liquid reversing valve 4-5; the liquid inlet pipeline 4-1 is used to push the kinetic energy transmission medium with pressure from the first hydraulic chamber to the second hydraulic chamber 3-3, and the oil return pipeline 4-2 returns the kinetic energy transmission medium to the kinetic energy transmission medium storage chamber 5.

[0056] In yet another specific embodiment of the present utility model, the liquid inlet pipeline 4-1 includes a first hydraulic chamber liquid inlet pipeline A 4-11, a first hydraulic chamber liquid inlet pipeline B 4-12, a liquid inlet pipeline 4-13 when the second push rod injects, and a liquid inlet pipeline 4-14 when the second push rod retracts; the oil return pipeline 4-2 includes an oil return pipeline 4-21 of the first hydraulic chamber, an oil return pipeline 4-22 when the second push rod injects, and an oil return pipeline 4-23 when the second push rod retracts; a main oil return pipeline 4-24; through the cooperation of the liquid inlet pipeline, the oil return pipeline, and the valve body control part, the injection pump of the present utility model can not only achieve micro-precision injection but also retract the second push rod to replace the syringe. For the setting of the liquid inlet pipeline, the oil return pipeline, and the valve body control part, other methods can also be used with the purpose of being able to realize the injection of the injection push rod 6-12 and the retraction of the second push rod 3-4.

[0057] In yet another specific embodiment of the present utility model, the hydraulic transmission micro-injection pump of the present application is further provided with a blockage alarm device 3-5, and the blockage alarm device 3-5 is installed at the end of the second hydraulic chamber 3-3.

[0058] In yet another specific embodiment of the present utility model, the hydraulic transmission micro-injection pump of the present utility model further includes a pressure relief valve 4-3, and the pressure relief valve 4-3 is installed on the opposite side of the piston B that pushes the drug into the liquid in the second hydraulic chamber 3-3, and the opening pressure of the pressure relief valve 4-3 is greater than the blockage alarm pressure. When the second push rod 3-4 cannot push the injection push rod 6-12 for some reason, the pressure in the second hydraulic chamber 3-3 rises, and at this time, the blockage alarm device 3-5 will be triggered; if the rise in the pressure in the second hydraulic chamber 3-3 does not trigger the blockage alarm device, when the pressure continues to rise to the limit, at this time the pressure relief valve 4-3 will open, and the machine will display an abnormal signal. The settings of the blockage alarm device 3-5 and the pressure relief valve 4-3 further ensure the injection accuracy of the injection pump, the infusion safety of the nasal-brain delivery drug, and the effectiveness of the infused drug.

[0059] In yet another specific embodiment of the present utility model, the hydraulic transmission micro-injection pump of the present utility model further includes a check valve 4-4 installed at the outlet end of the first hydraulic chamber. It is used to prevent liquid backflow and lock the push rod.

[0060] In yet another specific embodiment of the present utility model, the waterproof and breathable valve 5-1 is installed in the kinetic energy transmission medium storage cavity and is connected to the atmosphere.

[0061] The working principle of the present utility model is as follows: The rotation of the stepping motor 1-1 is controlled by a circuit program. The gear of the stepping motor drives the gear set to rotate and decelerate, and the gear set drives the lead screw 2-2 to operate. The lead screw 2-2 drives the push block 2-1 to perform reciprocating linear motion. When infusion administration is required, an inhalation kinetic energy transmission medium needs to be prepared. After the motor rotates in one direction, the valve 4-41 of the first hydraulic chamber and the valve 4-42 of the second hydraulic chamber are both closed, and the valve 4-43 between the first hydraulic chamber and the kinetic energy transmission medium storage chamber is opened. Through the first hydraulic chamber liquid inlet pipeline A4-11 and the first hydraulic chamber liquid inlet pipeline B4-12, the kinetic energy transmission medium is sucked from the kinetic energy transmission medium storage chamber into the first hydraulic chamber 3-1. After completion, the motor stops rotating. During infusion administration, the valves move. The valve 4-43 connecting the first hydraulic chamber to the kinetic energy transmission medium storage chamber is closed. At the same time, one end of the first hydraulic chamber 3-1 is connected to one end of the second hydraulic chamber 3-3. The push block 2-1 is pushed, so that the first push rod 3-2 of the first hydraulic chamber 3-1 together with the piston A is pushed, enabling the pressure liquid to enter the valve body. The valve body controls the infusion of the pressure liquid to one end of the second hydraulic chamber 3-3 and controls the forward movement of the second push rod 3-4. The liquid stored at the other end of the second hydraulic chamber 3-3 is controlled by a one-way valve to be transported to the kinetic energy transmission medium storage chamber 5 for storage. At the same time, the end of the second push rod 3-4 is connected to the tail end of the injection push rod 6-12, and the syringe piston is pushed by the second push rod 3-4 to output the medicinal liquid. When it is necessary to retract the second push rod 3-4 after the infusion administration is completed, the valve 4-41 of the first hydraulic chamber and the valve 4-42 of the second hydraulic chamber are both closed, and the valve 4-43 between the first hydraulic chamber 3-1 and the kinetic energy transmission medium storage chamber is opened to suck out a certain dose of liquid transmission medium into the kinetic energy transmission medium storage chamber. After completion, the motor stops rotating. The movement of the valve body makes one end of the first hydraulic chamber 3-1 communicate with the other end of the second hydraulic chamber 3-3. The motor rotates to infuse the pressure liquid to the other end of the second hydraulic chamber, and the second push rod 3-4 is retracted. The end of the second hydraulic chamber 3-3 that is not connected to the first hydraulic chamber 3-1 is connected to the kinetic energy transmission medium storage chamber, and the kinetic energy transmission medium is recovered into the kinetic energy transmission medium storage chamber 5.

[0062] The specific embodiments of the present utility model have been described above. It should be understood that the present utility model is not limited to the above specific implementation manners. Those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present utility model. Without conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other.

Claims

1. A hydraulic transmission micro-injection pump, comprising a motor drive part and a mechanical transmission part, characterized in that: It also includes a hydraulic transmission part, a valve body control part, a kinetic energy transmission medium storage chamber, and a liquid medicine assembly part; The hydraulic transmission part comprises: a first hydraulic chamber, a first push rod arranged in the first hydraulic chamber, a piston A which can be closely matched with the first push rod and the first hydraulic chamber; a second hydraulic chamber, a second push rod arranged in the second hydraulic chamber, a piston B which can be closely matched with the second push rod and the second hydraulic chamber; one end of the first push rod is connected to a push block of a stepping motor; kinetic energy transmission medium is installed in the first hydraulic chamber and the second hydraulic chamber; the kinetic energy transmission medium storage chamber comprises: two or more chambers, and also comprises a waterproof breathable valve; The valve body control part includes: a liquid inlet pipeline, an oil return pipeline and a valve body capable of switching the liquid flow direction; The medicine liquid assembly includes a syringe and optionally a syringe holder. The syringe includes a medicine liquid barrel and an injection push rod. The injection push rod is connected to the second push rod of the second hydraulic chamber and is used to inject the medicine liquid. The syringe holder is installed on the injection pump and is used to hold the syringe.

2. The hydraulic transmission micro-injection pump according to claim 1, characterized in that: The diameter of the first hydraulic chamber is smaller than the diameter of the second hydraulic chamber.

3. The hydraulic transmission micro-injection pump according to claim 1, characterized in that: The motor driving part includes: a stepper motor and a reducer, wherein the stepper motor includes a motor shaft, on which a gear is fixedly arranged; the reducer includes two or more gears of different sizes, and the gear on the motor shaft meshes with the gear of the reducer; And / or, the mechanical transmission part includes: a push block, a bearing, a guide rail, and a screw rod arranged on the bearing; wherein the push block can move on the screw rod.

4. The hydraulic transmission micro-injection pump according to claim 1, characterized in that: The kinetic energy transmission medium is an incompressible liquid.

5. The hydraulic transmission micro-injection pump according to claim 4, characterized in that: The kinetic energy transmission medium is oil, water or a mixture of the two.

6. The hydraulic transmission micro-injection pump according to claim 1, characterized in that: The first hydraulic chamber comprises a rigid cavity and a sealed piston A. One side of the piston A is the first push rod, and the other side of the piston is the kinetic energy transmission medium.

7. The hydraulic transmission micro-injection pump according to claim 4, characterized in that: The second hydraulic chamber comprises a rigid cavity and a sealed piston B. There is flowing kinetic energy transmission medium on both sides of the piston B. The back-and-forth movement of the piston B is controlled by the increase and decrease of the kinetic energy transmission medium.

8. The hydraulic transmission micro-injection pump according to claim 1, characterized in that: The valve body capable of switching the direction of liquid flow includes a pressure relief valve, a one-way valve and a liquid reversing valve; the liquid inlet pipeline is used to push the pressurized kinetic energy transmission medium in the first hydraulic chamber to the second hydraulic chamber, and the oil return pipeline is used to send the kinetic energy transmission medium back to the kinetic energy transmission medium storage chamber.

9. The hydraulic transmission micro-injection pump according to claim 8, characterized in that: The hydraulic transmission micro-injection pump is also provided with a blocking alarm device, and the blocking alarm device is installed outside the second hydraulic chamber.

10. The hydraulic transmission micro-injection pump according to claim 9, characterized in that: The hydraulic transmission micro-injection pump also includes a pressure relief valve, which is installed on the opposite side of the piston B that pushes the drug into the liquid in the second hydraulic chamber.

11. The hydraulic transmission micro-injection pump according to claim 10, characterized in that: The hydraulic transmission micro-injection pump also includes a one-way valve installed at the outlet end of the first hydraulic chamber to prevent liquid backflow and self-locking of the push rod.

12. The hydraulic transmission micro-injection pump according to claim 1, characterized in that: The waterproof breathable valve is installed at the top of the kinetic energy transmission medium storage chamber and is connected to the atmosphere.

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