Gear-type miniature syringe pump

Abstract

A gear-type miniature syringe pump, comprising a piston part. The piston part consists of a piston head (1) and a mounting base (2) which are connected to each other, the mounting base being not larger than a section of the piston head (1). The mounting base (2) is provided with at least one set of crawler gears (3) arranged around the axis of the piston head (1). The crawler gears (3) are in transmission connection with a worm (5) directly connected to an output shaft of a rotary driving mechanism (4) fixed to the mounting base (2). The piston driving mechanism is greatly reduced in size and integrated onto the piston, which effectively simplifies the structure of the syringe pump body, so that the syringe pump can be adapted to piston-adapted syringes with different lengths. The syringe pump is controllable during use and features high precision and low production costs and is therefore easy to popularize.

Description

Gear Micro Syringe Pump Technical Field

[0001] The present invention belongs to the technical branch of injection pumps in medical devices, and in particular relates to a portable gear-type micro injection pump. Background Art

[0002] Syringe pumps and infusion pumps are two mechanical drug delivery mechanisms. Their design aims to free up human hands while improving the accuracy of drug delivery, making the patient's treatment process more controllable, safe, efficient, and convenient. The main difference between these two mechanical pumps is that the syringe pump is a mechanical device for delivering drugs through syringes, while the infusion pump is a mechanical device for delivering drugs through infusion tubes. The two pumps work in different ways. The syringe pump usually replaces the piston of the syringe or pushes the syringe piston through an external structure to push the drug, so it acts directly on the drug storage container; while the infusion pump usually uses a peristaltic or extrusion structure to alternately squeeze the infusion tube, so that the drug in the infusion tube is continuously pushed, rather than acting on the container containing the drug.

[0003] Among them, for injection pumps, existing injection pumps are generally designed to be long and narrow in order to adapt to syringes of different lengths. The purpose is to allow the stroke of the pump body to adapt to the length of the syringe when pushing the liquid medicine. Therefore, in order to achieve this goal, a piston push rod with a long length and stroke is generally used to allow the injection pump to push the piston forward without interference from the syringe. Or, for plastic syringes, a cutting method can be used to push the piston while cutting the side wall of the syringe. This solution also requires the injection pump to have a longer length to adapt to the stroke requirements of cutting injection.

[0004] Regardless of the structure, the syringe pump inevitably becomes a relatively large and difficult-to-shrink device, making it more expensive and difficult to maintain. At the same time, it also places certain requirements on the space in the use venue. In primary medical places with relatively ordinary conditions, there are often no conditions for applying such high-precision drug delivery equipment, which has hindered the improvement of primary medical capabilities.

[0005] In this regard, there is no technical solution to effectively avoid the limitation of the pump size caused by the sufficient stroke length required for piston pushing. If most micro-syringe pumps want to avoid this problem, they often discard the syringe and choose to store the liquid medicine themselves, which is quite contradictory to the theme of syringe pumps. Summary of the Invention

[0006] In view of the technical defects existing in the background technology, the present invention proposes a gear-type micro-injection pump, which solves the above technical problems and meets practical needs. The specific technical solution is as follows:

[0007] A gear-type micro-injection pump includes a piston portion, which is composed of interconnected piston heads and a mounting base no larger than the cross-section of the piston head. The mounting base is provided with at least one set of creeping gears arranged around the axis of the piston head, and the mid-section of the creeping gear coincides with the radius of the piston head. The straight-line distance between the tooth top of the creeping gear and the axis of the piston head is greater than the radius of the piston head, so that when the piston portion is observed orthogonally from the axial direction of the piston head, only the tooth tip of the creeping gear protrudes outside the piston head. The creeping gear is transmission-connected to a worm directly connected to the output shaft of a rotary drive mechanism fixed to the mounting base.

[0008] As a further technical solution of the present invention, the number of the creeping gears is 2, 3, 4, 5, or 6.

[0009] As a further technical solution of the present invention, the mounting base is further provided with at least one set of balancing supports which are arranged together with the creeper gear in a rotationally symmetrical manner with respect to the axis of the piston head.

[0010] As a further technical solution of the present invention, the balancing support member is a cutting tool connected to the mounting base, with the cutting edge direction opposite to the arrangement direction of the creeping gear, or at least one rod or sheet connected to the mounting base, with the end direction opposite to the arrangement direction of the creeping gear and low damping at the end.

[0011] As a further technical solution of the present invention, the mounting base is vertically provided with a mounting panel, the creeping gear is hinged to the surface of the mounting panel, and the rotary drive mechanism is fixed to the end of the mounting panel.

[0012] As a further technical solution of the present invention, both ends of the worm are respectively connected to the output shaft of the rotary drive mechanism and the mounting base, and are hinged to the mounting base.

[0013] As a further technical solution of the present invention, the creeper gear is coaxially connected to a driven gear meshing with the worm.

[0014] As a further technical solution of the present invention, the longitudinal section of the teeth of the creeping gear is triangular.

[0015] As a further technical solution of the present invention, the rotary drive mechanism includes a driving part and an energy storage part which is integrally connected with the driving part and provides energy to the driving part.

[0016] As a further technical solution of the present invention, the driving part is a motor, the energy storage part is a battery, and the output shaft of the driving part is not on the axis of the piston part.

[0017] The beneficial effects of the present invention are that the piston drive mechanism is greatly reduced in size and integrated onto the piston, thereby effectively simplifying the structure of the injection pump body. In addition, there is no need to consider how to adapt to syringes of different lengths. As long as the piston can adapt to the syringe, a complete injection can be achieved regardless of the length of the syringe, without considering the length of the syringe stroke. At the same time, the entire process is controllable and highly precise, which can effectively reduce the production and practical costs of the injection pump and help promote its use in more primary medical workplaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic diagram of the overall structure of the injection pump of the present invention.

[0019] FIG2 is a schematic diagram of the orthogonal structure of the piston portion according to the present invention, taken from the piston head side in the axial direction.

[0020] FIG3 is an axial view 1 of the piston portion of the present invention.

[0021] FIG4 is a second axial view of the piston portion of the present invention.

[0022] FIG5 is a third axial view of the piston portion of the present invention.

[0023] FIG6 is an axial view 4 of the piston portion of the present invention.

[0024] FIG7 is a schematic diagram showing the assembly effect of the injection pump and the syringe according to the present invention.

[0025] FIG8 is a schematic diagram showing the working effect of the injection pump of the present invention.

[0026] FIG9 is a schematic diagram of a longitudinal section of the teeth of the creeper gear according to the present invention.

[0027] FIG10 is a schematic diagram of the assembly structure of the rotary drive mechanism of the present invention.

[0028] Among them: piston head 1, mounting base 2, mounting panel 20, creeping gear 3, rotation drive mechanism 4, driving part 40, energy storage part 41, worm 5, driven gear 6, balance support 7. DETAILED DESCRIPTION

[0029] The following describes the implementation of the present invention in conjunction with the accompanying drawings and relevant embodiments. The implementation of the present invention is not limited to the following embodiments, and the present invention relates to the relevant necessary components in this technical field, which should be regarded as the common knowledge in this technical field and can be known and mastered by technical personnel in this technical field.

[0030] As shown in Figure 1, the gear-type micro-injection pump includes a piston part, which is composed of an interconnected piston head 1 and a mounting base 2 no larger than the cross-section of the piston head 1. The mounting base 2 is provided with at least one set of creeping gears 3 arranged around the axis of the piston head 1, and the mid-section of the creeping gear 3 coincides with the radius of the piston head 1. The straight-line distance between the tooth top of the creeping gear 3 and the axis of the piston head 1 is greater than the radius of the piston head, so that when the piston part is observed orthogonally from the axial direction of the piston head 1, only the tooth tip of the creeping gear 3 protrudes outside the piston head 1, and the creeping gear 3 is transmission-connected to a worm 5 directly connected to the output shaft of a rotary drive mechanism 4 fixed on the mounting base 2.

[0031] As shown in Figures 1, 2 and 3, the difference between the injection pump described in the present invention and the existing micro-injection pump is mainly reflected in that it is no longer limited by the stroke of the syringe piston. The solution is to concentrate the power and moving structure for driving the syringe piston on the piston. Specifically, as shown in Figures 3 and 4, the injection pump described in the present invention can be regarded as a piston that can move autonomously along the inner wall of the syringe. As the crawling gear 3 moves along the inner wall of the syringe, the piston head 1 also pushes the medicine forward. As long as the piston head 1 can be moved, the crawling gear 3 can drive the piston head 1 to continue moving forward. Therefore, the configuration of the injection pump can be said to fundamentally avoid the influence of the syringe length limitation on the pushing structure of the injection pump itself. Theoretically, as long as the inner diameter of the syringe is compatible with the piston head 1 described in the present invention, the accurate and thorough drug delivery of the syringe can be completed.

[0032] In order to ensure the accuracy of pushing the piston to deliver the medicine, especially to enable the syringe pump of the present invention to meet the injection accuracy requirement of less than 1 mL per hour generally required by existing syringe pumps, the power and pushing structure of the present invention also adopt a gear pair transmission structure with high transmission accuracy and transmission efficiency. At the same time, this transmission structure also adopts the same transmission method as the existing syringe pump in principle. Therefore, under basic conditions, the syringe pump of the present invention is capable of high-precision injection and infusion.

[0033] Specifically, the reason why the present invention achieves high-precision injection is that the piston head 1 described in the present invention is integrated with the power structure that drives the piston head 1. The above-mentioned power structure is assembled on the mounting base 2 that is integrally connected to the piston head 1. In order to avoid affecting the sealing of the piston part, the diameter of the piston head 1 needs to be the largest - except for the tooth tip position of the creeping gear 3, ensure that when assembled with the syringe, the piston head 1 can fit tightly on the inner wall surface of the syringe to avoid air and medicine flowing along the gap between the piston head 1 and the inner wall surface of the syringe to affect the injection effect. On the mounting base 2, a creeping gear 3 for driving the piston head 1 forward is integrated. The creeping gear 3 is movably connected to the mounting base 2. The tooth top thereof is as described above, as shown in FIG2 , and the direction is axial along the piston head 1 toward the mounting base 2. The straight-line distance between the tooth top and the axis of the piston head 1 is greater than the radius of the piston head, so that when the piston part is observed orthogonally from the axial direction of the piston head 1, only the tooth tip of the creeping gear 3 protrudes outside the piston head 1, so that when the piston part is assembled into the syringe, only the creeping gear 3 is in close contact with the inner wall surface of the syringe except the piston head 1, and there is a high friction coefficient contact between the gear teeth of the creeping gear 3 and the inner wall of the syringe.

[0034] There are two ways to achieve the high friction coefficient here. One way is that if the syringe is a glass syringe that can be used repeatedly, the surface of the creeping gear 3 should be covered with a material with high contact friction, so that when the creeping gear 3 is in stress contact with the inner wall of the syringe, the static friction between them can overcome the resistance caused by the drug pressure on the piston head 1 when the drug solution is injected. However, this method is not the best choice. Since the inner wall environment of the syringe may be affected by other factors, relying solely on static friction to overcome resistance and push the piston head 1 forward is not the most reliable.

[0035] Therefore, another method is more preferred for the injection pump described in the present invention. In this method, as shown in Figure 8, the syringe is made of a disposable polymer material. The characteristic of this syringe is that it has a certain plasticity. When used in this type of syringe, the crawling gear 3 is preferably made of a material with a hardness greater than that of the syringe, generally an alloy material. Through stress contact with the inner wall of the syringe, the tip of the crawling gear 3 can penetrate the inner wall of the syringe to form a strong "grip", and as the injection proceeds, traces of the movement of the crawling gear 3 are left on the inner wall of the syringe, which can intuitively confirm whether there is any abnormality in the injection. Furthermore, the operator can directly judge whether the injection process is uniform and normal by the naked eye based on whether the tooth marks are uniform. Moreover, under this method, it is only necessary to ensure that the rotating drive mechanism 4 is not driven to reverse by the reaction force of the liquid medicine, and the crawling gear 3 can be firmly positioned at the current position engaged with the syringe when the movement occurs to ensure the controllable amount of medicine.

[0036] Regardless of the method, the rotary drive mechanism 4 is required to drive the creeping gear 3 to rotate through the worm 5 and move relative to the inner wall of the syringe, and then push the integrally connected piston head 1 forward to achieve the pushing of the medicine. Since the rotary drive mechanism 4 can use a micro motor, and the creeping gear 3, worm 5, piston head 1, mounting base 2 and other structures can also use miniaturized models, the volume of the injection pump can be made smaller and the production cost is lower. It is only necessary to prepare injection pump bodies of multiple specifications according to the diameter of the syringe. At the same time, the existing technology of micro motors can meet the needs of high-precision driving. Combined with the transmission precision characteristics of the gear pair, the injection pump described in the present invention can achieve the needs of high-precision injection on the basis of low-cost production.

[0037] Generally speaking, in the present invention, the rotary drive mechanism 4 directly drives the creeping gear 3 to rotate through the worm 5 connected to its output shaft, but since the creeping gear 3 also needs to be used to contact the syringe to achieve displacement, the transmission method between the worm 5 and the creeping gear 3 is not limited to direct connection to complete the transmission. At the same time, in order to ensure the stability of torque transmission during rotation, it is not limited to using a structure similar to a bearing to improve the rotation efficiency of the creeping gear 3 and the worm 5. However, it is also not conducive to cost control, and the existing structure has already met the use requirements.

[0038] Generally speaking, except for the creeping gear 3 and the rotary drive mechanism 4, the entire piston part can be made of synthetic resin material. On the premise that the strength can meet the requirements, the production and use costs of the injection pump can be greatly reduced, which is conducive to its promotion and use in primary medical facilities.

[0039] In one of the preferred embodiments of the present invention, the number of the creeping gears 3 is 1, 2, 3, 4, 5, or 6. Generally speaking, the more creeping gears 3 there are, the more stable the contact between the piston portion and the syringe is. The rotationally symmetrical arrangement is more conducive to the reliability of the torque transmission method, and the transmission accuracy of the injection pump can also be better guaranteed. However, too many creeping gears are not conducive to the miniaturization of the equipment. At the same time, higher design requirements will be put forward for the composition of the injection pump during installation and layout, which will undoubtedly increase the production and use costs of the injection pump. Therefore, generally speaking, the number should not exceed 6. However, this does not mean that the injection pump of the present invention can only use a maximum of 6 creeping gears 3 as the end actuator for pushing the piston head 1, but that the balance between the comprehensive cost and practical effect of the structure is better. However, in the case where the number of creeping gears 3 is 1, it may rely solely on the creeping gear 3 as a driving member.

[0040] As a further preferred embodiment of the above embodiment, the mounting base 2 is further provided with at least one set of balancing supports 7 which are arranged together with the creeper gear 3 in a rotationally symmetrical manner with respect to the axis of the piston head 1 .

[0041] 4 and 7 , it should be noted that in the injection pump described in the present invention, the creeping gear 3 is preferably arranged with its tooth end face parallel to the radius of the piston head 1, and is arranged on the mounting base 2 in a rotationally symmetrical form, to ensure that when it contacts the inner wall of the syringe, the direction of the resultant force of the creeping gear 3 can correctly act on the axis of the piston head 1, so that the piston head 1 can be pushed forward stably and accurately.

[0042] As shown here in combination with Figures 3, 5 and 6, the number and form of the balancing support 7 are not a single one. In the present invention, when the number of the crawling gears 3 is 1, the piston part can realize the function of liquid flow, but because the force relationship of the crawling gear 3 is in a non-equilibrium state when the number is 1, in this state, if only the crawling gear 3 is subjected to force, and the rest only rely on the contact force between the piston head 1 or the side wall of the mounting base 2 and the inner wall of the syringe to balance, the resistance that the crawling gear 3 needs to overcome is relatively large, especially the side surface of the piston head 1 to which it is close, the contact force between the inner wall of the syringe is not perpendicular to the inner surface of the syringe, there will be a large friction feedback, and there is a hidden danger of sealing. However, as long as it does not fall into the range of the friction angle, self-locking will not occur, and the crawling gear 3 can drive the piston part forward normally.

[0043] Therefore, for the case where the number of creeping gears 3 is one, it is preferred to provide a balancing support 7 facing in the opposite direction relative to the creeping gear 3 to help reduce the friction resistance of the creeping gear 3 and at the same time help to improve the sealing of the piston head 1. The balancing support 7 referred to here is provided with at least one group of balancing support members 7 that are rotationally symmetrically arranged with the creeping gear 3 to the axis of the piston head 1. The number does not have to be equal to the number of creeping gears 3, but equality is a preferred embodiment. It is only necessary to ensure that the overall arrangement formed between the balancing support members 7 and the creeping gear 3 is rotationally symmetrical with respect to the axis of the piston head 1 to ensure the optimization of the force. For example, in the case of one creeping gear 3, two balancing support members 7 are used, and the central angle between them is guaranteed to be 120°.

[0044] If the number of creeper gears 3 exceeds one, the creeper gear 3 itself can satisfy the layout of rotational symmetry with respect to the axis of the piston head 1, as shown in FIG4 , thereby optimizing the overall force relationship. However, a balancing support member 7 can also be added at this time, as shown in FIG5 or FIG6 , to ensure that the overall layout is still rotationally symmetrical.

[0045] 5 and 6 , as a further preferred embodiment of the above-mentioned embodiment, the balancing support member 7 is a cutting tool connected to the mounting base 2, with the cutting edge direction opposite to the arrangement direction of the creeping gear 3, or is at least one rod or sheet member connected to the mounting base 2, with the end direction opposite to the arrangement direction of the creeping gear 3 and low damping at the end.

[0046] As a support structure for balancing the force relationship, the balancing support member 7 can be in the form of a cutting tool, and the direction of its cutting edge is similar to that of the creeping gear 3. As shown in the figure, it can reduce the friction between itself and the inner wall of the syringe while providing support force, so that the creeping gear 3 can move more smoothly and naturally. At the same time, it can also be more than one set of cutting tools. As shown in Figure 6, the balancing support member 7 can be regarded as a triple cutting tool style, so as to achieve more uniform and stable support; if the balancing support member 7 is not a cutting tool, it can also be in the form of a rod or a sheet that will not cause cutting scratches on the inner wall of the syringe, which can also play the role of supporting the balanced force relationship. However, in order to ensure that the friction force is not too large, the part in contact with the inner wall of the syringe needs to be treated with a low-damping surface. At the same time, combined with Figure 6, the balancing support member 7 can be regarded as a triple rod or sheet, so that the piston head 1 can obtain a more uniform and stable force distribution.

[0047] 1 and 3 , one of the preferred embodiments of the present invention is that the mounting base 2 is vertically provided with a mounting panel 20, the crawling gear 3 is hinged to the surface of the mounting panel 20, and the rotary drive mechanism 4 is fixed to the end of the mounting panel 20. In this embodiment, the mounting panel 20 is further required to serve as the mounting and positioning structure of the crawling gear 3 and the rotary drive mechanism 4. The assembly separated from the mounting base 2 is more conducive to the rational spatial layout of the transmission structure, and the structure can be made in an integrated molding manner, reducing the use of other positioning structures, which is conducive to reducing production costs and improving transmission efficiency.

[0048] As shown in Figure 1, as a further preference of the above embodiment, the two ends of the worm 5 are respectively connected to the output shaft of the rotary drive mechanism 4 and the mounting base 2, and are hinged to the mounting base 2. In this way, the worm 5 can also serve as a support for stabilizing the rotary drive mechanism 4, so that the rotary drive mechanism 4 can stably transmit torque to the worm 5, and then output it to the creeping gear 3 through the worm 5, driving the piston to move forward along the inner wall of the syringe.

[0049] As shown in Figure 1, similarly, as a further preference of the same embodiment, the creeping gear 3 is coaxially connected to a driven gear 6 meshing with the worm 5. This embodiment is a better choice to solve the material and transmission reliability problems of the creeping gear 3. By allowing the creeping gear 3 to completely break away from its direct connection with the worm 5, the coaxially connected driven gear 6 can better select a tooth shape that meshes with the worm 5, thereby improving the efficiency of the transmission torque, so that the creeping gear 3 can be fully involved in the interaction with the inner wall of the syringe, thereby improving the reliability and precision of the equipment, and allowing the creeping gear 3 to accurately output the torque information from the rotary drive mechanism 4, thereby ensuring the controllable and precise drug injection.

[0050] As shown in Figure 9, one of the better embodiments of the present invention, the longitudinal section of the gear teeth of the crawling gear 3 is triangular. This embodiment is only an external shape indicator adaptively designed for how the crawling gear 3 can better engage with and penetrate the inner wall of the syringe. Generally speaking, if the contact efficiency between the crawling gear 3 and the inner wall of the syringe can be improved, any other form of external shape can also meet the equipment and use requirements of the injection pump described in the present invention.

[0051] Referring to Figure 10, one of the preferred embodiments of the present invention, the rotary drive mechanism 4 includes a drive part 40 and an energy storage part 41 integrally connected to the drive part 40 and providing energy for the drive part 40. In this embodiment, the drive part 40 can generally be regarded as a micro drive motor, and the energy storage part 41 can be regarded as a micro battery, wherein the drive part 40 should meet the requirements of controllable rotation to ensure that under high-precision injection conditions (injection volume <1mL / h), the injection pump can complete the injection work well. Preferably, the rotary drive mechanism 4 can also be equipped with a control circuit connected to the drive part 40 and the energy storage part 41 circuit to facilitate the operator to perform electronic control.

[0052] As shown in Figures 1 and 10, as a further preference of the above embodiment, the driving part 40 is a motor, the energy storage part 41 is a battery, and the output shaft of the driving part 40 is not on the axis of the piston part 1. The setting of this structure is conducive to the installation layout of the creeping gear 3 in a way that it can more efficiently contact the inner wall surface of the syringe, especially allowing the driven gear 6 coaxially connected to the creeping gear 3 to have sufficient assembly space.

[0053] As a further preference, in order to improve the "grip" of the crawling gear 3 and avoid the problem of its reversal under the reaction force of the drug pressure, and also to reduce the energy consumed by the rotation drive mechanism 4 to overcome the resistance, an elastic pre-tightening mechanism directly connected to the crawling gear 3 can be provided on the mounting base 2, the mounting panel 20, and the rotation drive mechanism 4, such as a spring, an elastic rubber band or other simple structural connecting piece, so that the crawling gear 3 has a potential energy to resist the reaction force of the drug pressure when the rotation drive mechanism 4 is not driven. At the same time, in order to prevent the above-mentioned elastic pre-tightening mechanism from triggering the injection of the drug in advance and causing a medical accident, a trigger-type safety device, such as a buckle, can also be provided for the elastic pre-tightening mechanism. The trigger or release structure prevents the elastic pre-tightening mechanism from triggering the piston head 1 to release liquid before the injection occurs, and at the same time reduces the load of the elastic pre-tightening mechanism on the rotary drive mechanism 4, reduces the energy consumed by the rotary drive mechanism 4 to overcome the resistance when driving the piston head 1 to move, extends the service life of a single injection pump, and reduces the frequency of replacing the energy storage structure of the rotary drive mechanism 4. Compared with the existing injection pump, the setting of the above structure does not increase the production cost of the injection pump configuration of the present invention too much, but it greatly extends the operating time of the rotary drive mechanism 4, and is also beneficial for primary medical places with more frequent medical activities to cope with more patients, and facilitates the promotion and use of the injection pump of the present invention in a large number of medical places.

[0054] In summary, the present invention significantly reduces the size of the piston drive mechanism, making it comparable to the traditional syringe pump configuration, abandoning the frame for mounting the stroke rod and integrating it directly onto the piston for injection, thereby effectively simplifying the structure of the syringe pump body. There is no need to consider how to adapt to syringes of different lengths. As long as the piston head 1 can fit the inner diameter of the syringe, a complete injection can be achieved regardless of the length of the syringe, without having to consider the length of the syringe stroke. At the same time, the entire process is controllable and highly precise, which can effectively reduce the production and practical cost of the syringe pump and help promote its use in more primary medical workplaces. Compared with existing clamp-type syringe pumps or syringe pumps that have abandoned syringes, the syringe pump described in the present invention has a simpler configuration, lower production cost, and lower usage requirements. It is more adaptable to the existing environment of the vast majority of primary medical care sites and can significantly improve primary medical care conditions.

[0055] The above description is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A gear-type micro-injection pump, comprising a piston portion, characterized in that: The piston part is composed of interconnected piston heads and a mounting base no larger than the cross-section of the piston head. The mounting base is provided with at least one set of creeper gears arranged around the axis of the piston head, and the middle cross-section of the creeper gear coincides with the radius of the piston head. The straight-line distance between the tooth top of the creeper gear and the axis of the piston head is greater than the radius of the piston head, so that when the piston part is observed orthogonally from the axial direction of the piston head, only the tooth tip of the creeper gear protrudes outside the piston head. The creeper gear is transmission-connected to a worm directly connected to the output shaft of a rotating drive mechanism fixed on the mounting base.

2. The gear-type micro-injection pump according to claim 1, characterized in that: The number of the creeping gears is 1, 2, 3, 4, 5, or 6.

3. The gear-type micro-injection pump according to claim 2, characterized in that: The mounting base is also provided with at least one group of balancing supports which are arranged together with the creeper gear in a rotationally symmetrical manner with respect to the axis of the piston head.

4. The gear-type micro-injection pump according to claim 3, characterized in that: The balance support is a cutting tool connected to the mounting base, with the cutting edge direction opposite to the arrangement direction of the creeping gears, or at least one rod or sheet connected to the mounting base, with the end direction opposite to the arrangement direction of the creeping gears and low damping at the end.

5. The gear-type micro-injection pump according to claim 1, characterized in that: The mounting base is vertically provided with a mounting panel, the creeping gear is hinged to the surface of the mounting panel, and the rotary drive mechanism is fixed to the end of the mounting panel.

6. The gear-type micro-injection pump according to claim 5, characterized in that: The two ends of the worm are respectively connected to the output shaft of the rotary drive mechanism and the mounting base, and are hinged to the mounting base.

7. The gear-type micro-injection pump according to claim 5, characterized in that: The creeper gear is coaxially connected with a driven gear meshing with the worm.

8. The gear-type micro-injection pump according to claim 1, characterized in that: The longitudinal section of the gear teeth of the creeper gear is in the shape of a triangle.

9. The gear-type micro-injection pump according to claim 1, characterized in that: The rotary drive mechanism comprises a driving part and an energy storage part which is integrally connected with the driving part and provides energy for the driving part.

10. The gear-type micro-injection pump according to claim 9, characterized in that: The driving part is a motor, the energy storage part is a battery, and the output shaft of the driving part is not on the axis of the piston part.

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