Pre-tightening structure of gear injection pump

Abstract

The utility model belongs to technical branches of injection pumps in medical instruments, and particularly relates to a pre-tightening structure of a gear injection pump, which comprises a base, a main body part of the base is movably connected with a driven gear and an advancing wheel coaxially connected with the driven gear, the driven gear is meshed with a worm, one end of the worm is movably connected with the base, and the other end of the worm is meshed with the advancing wheel. The driven gear is coaxially connected with an elastic pre-tightening piece, one end of the elastic pre-tightening piece is fixedly connected with the rotating shaft where the driven gear is located, and the other end of the elastic pre-tightening piece is fixedly connected with the base. According to the novel structure, under the condition that the size and the reliability of an existing infusion pump structure are not affected, the installation space is reasonably utilized, the elastic pre-tightening piece is compactly arranged, the energy consumption of the motor is reduced, and the service life of equipment is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the injection pump technology branch in medical apparatus and instruments, and concretely relates to a pre-tightening structure of gear injection pump. BACKGROUND

[0002] The injection pump and the infusion pump both belong to mechanical medicine delivery structure, and the design purpose is to liberate hands, improve the precision of medicine delivery, make the treatment process of patients more controllable, safe, efficient, convenient, however, the existing mainstream injection pump or infusion pump has certain limitation, and the defects have been disclosed in the prior art CN117224776A, and the prior art CN117224776A proposes a gear type micro injection pump, which has the advantages of compactness, reliability, low manufacturing cost and high use flexibility, and well solves the existing problems.

[0003] Only for the above-mentioned existing design, still has some improvement space, specifically, due to the design idea of miniaturization, the volume of all parts of the above-mentioned existing design is small, including the power supply, and a small, micro battery with small volume is also selected, although the capacity of the high-energy button cell is more, but in long time use, the consumption of motor to battery energy storage is still not negligible, and the problem of early depletion of battery energy may occur in the case of long infusion time, which causes certain inconvenience to the application of the existing design.

[0004] Therefore, in order to further improve the reliability and practicability of the existing design, it is necessary to optimize the energy consumption level of the motor without obviously changing the structure of the existing technology, prolong the service life of the equipment, and also will not obviously affect the manufacturing cost of the equipment. CONTENT OF THE UTILITY MODEL

[0005] In view of some problems in the background art, the utility model is based on the existing design, through reasonable thinking and improvement practice demonstration, a new type of gear injection pump pre-tightening structure is proposed, which solves the above-mentioned technical problems and meets the actual demand, and the specific technical scheme is as follows:

[0006] The gear injection pump pre-tightening structure comprises a base, a driven gear movably connected to a main body part of the base, a travel wheel coaxially connected to the driven gear, a worm gear meshingly connected to the driven gear, one end of the worm gear movably connected to the base, the other end of the worm gear drivingly connected to an output end of a motor, a piston part fixedly connected to an end of the base, an elastic pre-tightening member coaxially connected to the driven gear, one end of the elastic pre-tightening member fixedly connected to a rotating shaft of the driven gear, the other end of the elastic pre-tightening member fixedly connected to the base, and the elastic pre-tightening member applying a tangential force to the rotating shaft of the driven gear in a direction suitable for a positive torsional force of the motor, so that the driven gear and the worm gear are self-locked when the elastic pre-tightening member is in a pre-tightening state and the motor is stopped.

[0007] As a further technical solution of the utility model, the elastic pre-tightening member is a rubber band member with one end connected to the driven gear and the other end connected to the base.

[0008] As a further technical solution of the utility model, the elastic pre-tightening member is a rubber band member with one end connected to the driven gear and the other end connected to the base.

[0009] As a further preferred solution of the above technical solution, the elastic pre-tightening member is wound around the surface of a conical or cylindrical winding drum, and the shaft end of the winding drum is hinged to the base.

[0010] As a further technical solution of the utility model, one end of the base connected to the piston part is a fitting member with a cross-sectional edge not exceeding that of the piston part, the other end is a connecting member perpendicularly connected to the end surface of the fitting member, the motor is fixed to the surface of the connecting member, the driven gear, the travel wheel and the elastic pre-tightening member are all connected to the connecting member, and the worm gear is connected between the fitting member and the output end of the motor.

[0011] As a further preferred solution of the above technical solution, the connecting member is a sheet-shaped body provided on the fitting member, the driven gear and the travel wheel are coaxially connected to one side surface of the connecting member, and the elastic pre-tightening member is coaxially connected to the opposite side surface of the connecting member.

[0012] As a further technical solution of the utility model, the number of the driven gears and the travel wheels is not less than one set, and the number of the elastic pre-tightening members is also not less than one set.

[0013] The utility model has the beneficial effects that:

[0014] The utility model discloses a pre-tightening structure of gear injection pump, which is characterized by the following technical scheme: a base (1) is provided with a matching piece (100) and a connecting piece (101), the connecting piece (101) is connected with a driven gear (2), the driven gear (2) is connected with a running wheel (3), the running wheel (3) is connected with a worm (4), the worm (4) is connected with a motor (5), the motor (5) is connected with a piston part (6), the piston part (6) is connected with an elastic pre-tightening piece (7), and the elastic pre-tightening piece (7) is connected with a winding drum (8). BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 It is a sectional structure schematic view of the pre-tightening structure of the gear injection pump.

[0016] Fig. 2 It is a bottom structure schematic view of the pre-tightening structure of the gear injection pump.

[0017] Fig. 3 It is a three-dimensional structure schematic view of the pre-tightening structure of the gear injection pump.

[0018] Among them: base 1, matching piece 100, connecting piece 101, driven gear 2, running wheel 3, worm 4, motor 5, piston part 6, elastic pre-tightening piece 7, winding drum 8. DETAILED DESCRIPTION

[0019] The embodiments of the utility model will be described below in combination with the drawings and related examples, and the embodiments of the utility model are not limited to the following examples, and the utility model relates to the necessary components in the related technical field, which should be regarded as the known technology in the technical field and can be known and mastered by the technical personnel in the technical field.

[0020] REFERENCE Figs. 1-3The utility model discloses a pre -tightening structure of gear injection pump in the medical instrument technical field, including base 1, the main part of base 1 swing joint has driven gear 2 and with driven gear 2 coaxial connection of the travel wheel 3, driven gear 2 is engaged to be connected on a worm 4, one end of worm 4 is swing joint with base 1, the other end transmission is connected to the output end of a motor 5, the end of base 1 is fixedly connected with piston part 6, driven gear 2 coaxial connection has a elastic pre -tightening piece 7, one end of elastic pre -tightening piece 7 is fixedly connected with the rotation axis of driven gear 2, the other end is fixedly connected with base 1, and elastic pre -tightening piece 7 is applied to the tangential force of the rotation axis of driven gear 2 and the direction of the positive torsional force of motor 5 is adapted, so that when elastic pre -tightening piece 7 is pre -tightening state and motor 5 also stops, driven gear 2 and worm 4 are mutually self -locking, more specifically, driven gear 7 is one of worm wheel or helical gear.

[0021] First, the technical terms need to be explained, wherein, driven gear 2 and worm 4 are engaged, because the worm can produce the engagement mode of the transmission pair in addition to the worm wheel, according to the technical information disclosed in "Calculation of Time-varying Engagement Stiffness and Nonlinear Dynamic Characteristics of Worm-helical Gear Transmission Pair" (Liu Fei, Feng Jie, Chen Yonghong, Mechanical Design, May 2024, Vol. 41, No. 5), in fact, the helical gear and the worm can also constitute a transmission pair, and the commonality of the worm wheel and the helical gear is that both belong to the gear category. Therefore, the type of driven gear 2 referred to as "gear" is actually a helical gear and a worm wheel. The engagement mode of the helical gear and the worm actually follows the principle of modulus adaptation, but in the preferred case, the transmission effect of the worm and the worm wheel is the best.

[0022] In combination with the prior art features, the utility model further explains the improvements. The structure of the prior art gear injection pump is characterized by adjusting the source of the pushing force of the pumping piston from the structure fixed outside the syringe to the independent travel of the piston body. Therefore, the primary configuration of all components is miniaturization, which is well reflected in the prior art. The most important structure is the accurate matching of the worm and worm gear pair, the self-locking feature, and the stable transmission power. When the motor 5 does not rotate, the travel wheel 3 connected coaxially with the driven gear 2 as a worm wheel will not reverse and retreat due to the reaction force. This helps to reduce the probability of errors during high-precision infusion of the injection pump. However, it is foreseeable that the motor 5 and its energy supply module, which is usually a small battery in such a small size, are also miniaturized. The energy density of the small battery plays a fundamental role in the continuous operation of the device within a reasonable time, and the energy efficiency of the motor 5 has a decisive influence on the operation time.

[0023] In the case of long time infusion, the above prior art can cause the output power of the motor 5 to decrease due to the voltage drop caused by the decrease in the power storage of the miniaturized battery, which directly affects the travel speed of the travel wheel 3 drivingly connected with the motor 5, and further causes interference to the amount of infusion liquid per unit time. In medical applications with high precision requirements, the error of this part can have a negative effect on the treatment effect. However, the space structure of the infusion pump itself is already relatively compact, and it is not suitable to increase structures such as bearing bush, high-performance motor or other structures that improve transmission efficiency and reduce energy consumption. Therefore, simple structural optimization cannot have a significant effect.

[0024] In the utility model, considering the compact structure of the existing design, the assembly position of the coaxially arranged driven gear 2 and the shaft body of the travel wheel 3 which already has a certain space for movement and becomes the elastic pre-tightening piece 7 is a relatively reasonable position selected after consideration. After pre-tightening the elastic pre-tightening piece 7 before assembling on the infusion pump during production, the elastic force of the elastic pre-tightening piece 7 is directly applied to the rotating tangential traction in the direction of the travel direction of the piston part 6 during use, which is a necessary choice to effectively reduce the output load of the motor 5. Under the self-locking effect of the worm and gear pair, the tangential force applied by the elastic pre-tightening piece 7 on the shaft body will not drive the shaft body to rotate, so it will not drive the travel wheel 3 to advance in the state of motor 5 stop. Therefore, the load of the motor 5 is not increased, but under the action of the resultant force, the load of the motor 5 is reduced, the endurance time of the equipment in normal working condition is effectively prolonged, and the most critical point is that the structure is not complex and does not require much setting space. Under the premise of not significantly increasing the manufacturing cost of the equipment, the endurance problem of the existing design is reasonably solved.

[0025] Among them, the driven gear 2 is any one of a worm or a helical gear. The reason is as described above. Further, in the production and application environment involved in the utility model, the source of the driven gear 2 generally selected is plastic. It is recorded in the Research on the Change Law of Meshing Force of Plastic Helical Gear and Steel Worm (Yongxu Yun, Hong Hu, Jingning Ta, Mechanical Transmission, No. 11, 2018, 27-32) that plastic helical gears are prone to wear and fatigue failure in some positions when cooperating with worms. Therefore, the worm is preferably selected. However, since the structure of the utility model is relatively simple, if it is designed as a disposable or short-term use product, the application effect of the helical gear will not differ much from that of the worm of the same material. Therefore, both types of driven gears 2 can be selected as the gears of the utility model.

[0026] In combination with Figs. 1-3As one of preferred embodiments of the utility model, the elastic pre-tightening part 7 is a rubber band part with one end connected with the driven gear 2 and the other end connected with the base 1, compared with the previous embodiment, although the service life of the rubber band part in the present embodiment is shorter, the use cost is lower, and the use requirement can be met in general use occasions, as long as the placement time is not too long (before the aging of the rubber material), the similar effect as the elastic condition can be achieved.

[0027] In combination with Figs. 1-3 As one of preferred embodiments of the utility model, the elastic pre-tightening part 7 is a rubber band part with one end connected with the driven gear 2 and the other end connected with the base 1, compared with the previous embodiment, although the service life of the rubber band part in the present embodiment is shorter, the use cost is lower, and the use requirement can be met in general use occasions, as long as the placement time is not too long (before the aging of the rubber material), the similar effect as the elastic condition can be achieved.

[0028] In combination with Figs. 1-3 As one of preferred embodiments of the utility model, the elastic pre-tightening part 7 is wound on the surface of a conical or cylindrical winding drum 8, and the shaft end of the winding drum 8 is hinged to the base 1, although the elastic pre-tightening part 7 can accumulate elastic potential energy without early release under the premise of not needing other components, if the winding drum 8 structure is set, the elastic pre-tightening part 7 can be stored in a relatively small space without disorderly stacking, which helps the elastic pre-tightening part 7 to orderly release elastic potential energy to the rotating shaft of the driven gear 2, and the structural reliability of the equipment can be further improved.

[0029] In combination with Figs. 1-3 As one of preferred embodiments of the utility model, the base 1 is connected with the piston part 6 at one end, and the other end is connected with the connecting part 101 which is perpendicular to the end surface of the matching part 100, the motor 5 is fixed on the surface of the connecting part 101, the driven gear 2, the traveling wheel 3 and the elastic pre-tightening part 7 are connected with the connecting part 101, and the worm 4 is connected between the matching part 100 and the output end of the motor 5, the structure is based on the preferred embodiment of the existing design, and the feasibility of the elastic pre-tightening structure of the utility model can be verified reversely.

[0030] In combination with Figs. 1-3As shown, as a further preferred embodiment of the above embodiment, the connecting piece 101 is a sheet-shaped body provided on the fitting piece 100, the driven gear 2 and the travel wheel 3 are coaxially connected to one side surface of the connecting piece 101, and the elastic pre-tightening piece 7 is coaxially connected to the opposite side surface of the connecting piece 101 with the driven gear 2 and the travel wheel 3. Further, the elastic pre-tightening piece 7 is arranged on the rotating shaft of the driven gear 2 opposite to the connecting piece 101, and the space of this part is larger, which is helpful for the compact assembly of the elastic pre-tightening piece 7.

[0031] In combination Figs. 1-3 As shown, as one of the preferred embodiments of the utility model, the number of the driven gear 2 and the travel wheel 3 is not less than one set, and the number of the elastic pre-tightening piece 7 is also not less than one set. This embodiment is also based on the preferred application mode of the existing design. Generally speaking, the number of the driven gear 2 and the travel wheel 3 corresponds to the number of the elastic pre-tightening piece 7. However, since the increase in the number of the driven gear 2 and the travel wheel 3 will be equivalent to compressing the spare assembly space of the equipment, and the existing technology can actually travel under the premise that only one set of travel wheel 3 has power, therefore, as long as the elastic pre-tightening piece 7 is arranged on the shaft of at least one set of the driven gear 2 and the travel wheel 3, the technical purpose of reducing energy consumption and prolonging the operation time of the equipment can be met.

[0032] In summary, compared with the existing design, on the basis of not excessively increasing the overall manufacturing cost, the utility model compactly arranges the pre-tightening elastic structure in the small infusion pump structure. The structure does not affect the working mode and mechanical relationship of the original structure, and does not have a negative impact on the reliability of the equipment, but rather has more gains.

[0033] Specifically, in the improved novel structure of the utility model, the elastic pre-tightening torsion around the shaft can be applied to the travel wheel of the gear injection pump. During the infusion of the liquid medicine, the elastic pre-tightening force can form an effective resultant force with the motor output torque, thereby reducing the energy consumption of the motor and effectively prolonging the energy supply time of the storage power supply. Moreover, by using the self-locking principle of the worm gear, the elastic pre-tightening piece will not release energy by itself under the premise that the motor does not work, thereby avoiding the premature failure of the elastic pre-tightening piece and not increasing the load on the motor. Overall, compared with the existing technology, the overall structure of the utility model has no obvious difference in compactness, and is reliable and ingenious. It has a good optimization effect on the miniaturization improvement of the precision infusion equipment.

[0034] The above is only the preferred embodiment of the utility model, and it should be pointed out that for ordinary technical personnel in the technical field, without departing from the principle of the utility model, a number of improvements and refinements can be made, and these improvements and refinements should also be considered within the protection scope of the utility model.

Claims

1. A pre-tightening structure of a gear injection pump, comprising a base, a main body part of the base movably connected with a driven gear and a running wheel coaxially connected with the driven gear, the driven gear movably connected with a worm, one end of the worm movably connected with the base and the other end drivingly connected with an output end of a motor, an end part of the base fixedly connected with a piston part, characterized in that, The driven gear is coaxially connected with an elastic pre-tightening member, one end of the elastic pre-tightening member is fixedly connected with the rotating shaft of the driven gear, the other end is fixedly connected with the base, and the tangential force of the elastic pre-tightening member applied to the rotating shaft of the driven gear is adapted to the direction of the positive torsional force of the motor, so that the driven gear and the worm are self-locked when the elastic pre-tightening member is in a pre-tightening state and the motor is also stopped.

2. The pre-tightening structure of a gear syringe pump according to claim 1, characterized in that, The elastic pre-tightening member is a spring member with one end connected with the driven gear and the other end connected with the base.

3. The pre-tightening structure of a gear syringe pump according to claim 1, characterized in that, The elastic pre-tightening member is a rubber spring member with one end connected with the driven gear and the other end connected with the base.

4. The pre-tightening structure of a gear syringe pump according to claim 2 or 3, characterized in that, The elastic pre-tightening member is wound on the surface of a conical or cylindrical winding drum, and the shaft end of the winding drum is hinged to the base.

5. The pre-tightening structure of a gear syringe pump according to any one of claims 1 to 3, characterized in that, One end of the base connected with the piston part is a fitting member with a cross-sectional edge not exceeding that of the piston part, and the other end is a connecting member vertically connected to the end surface of the fitting member, the motor is fixed to the surface of the connecting member, the driven gear, the running wheel and the elastic pre-tightening member are connected with the connecting member, and the worm is connected between the fitting member and the output end of the motor.

6. The pre-tightening structure of a gear syringe pump according to claim 5, characterized in that, The connecting member is a sheet-shaped body arranged on the fitting member, the driven gear and the running wheel are coaxially connected to one side surface of the connecting member, and the elastic pre-tightening member is coaxially connected to the opposite side surface of the connecting member with the driven gear and the running wheel.

7. The pre-tightening structure of a gear syringe pump according to claim 5, characterized in that, The number of the driven gears and the running wheels is not less than one set, and the number of the elastic pre-tightening members is also not less than one set.

8. The pre-tightening structure of a gear syringe pump according to claim 1, characterized in that, The driven gear is a worm gear.

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