Miniature gear pump

Abstract

The invention relates to the field of fluid conveying, in particular to a miniature gear pump. The micro gear pump comprises a driving speed reducing mechanism, a meshing mechanism and a pump cover assembly, wherein a motor driving end of the driving speed reducing mechanism penetrates into a motor cavity for sleeving a first driving wheel; a first driven wheel of the meshing mechanism is meshed with a first driving wheel, a driving shaft sequentially penetrates through a positioning sealing assembly, a gear pump cavity and a second driving wheel, the second driving wheel and a second driven wheel are meshed in the gear pump cavity, and a water inlet groove, a water outlet groove, a corresponding water inlet and a corresponding water outlet are formed in the gear pump cavity. A pump cover of the pump cover assembly covers the gear pump cavity and is fixed through a first screw piece. Through the unique structural design, the size of the gear pump can be reduced, the power density can be kept, meanwhile, the transmission structure is simplified, the space utilization rate is increased, noise is lowered, the defects of a traditional gear pump are overcome, and the urgent requirement of the market is met.

Description

Technical Field

[0001] This application relates to the field of fluid transport, and in particular to a miniature gear pump. Background Technology

[0002] Pumps, as energy conversion devices, convert external energy such as electrical energy into mechanical energy to transport or increase the pressure of liquids or gases, and are widely used in industrial and civil fields. Among them, gear pumps, a common type of positive displacement pump, rely on the rotational motion of a pair of meshing gears within the pump chamber. When the suction-side gears disengage, a partial vacuum is created to draw in the medium; when the discharge-side gears engage, the reduced volume forces the medium out, thus achieving continuous and stable fluid transport. These pumps have advantages such as simple structure, low cost, good pressure resistance, and reliable operation, and are commonly found in various large industrial equipment and engineering machinery. However, with the increasing demands on miniaturized devices (such as printers and portable medical instruments) for fluid transport components in terms of space layout, noise control, and energy efficiency, the traditional gear pump structure, when directly applied to miniaturized applications, is gradually revealing the following inherent defects: 1. The system is bulky and has low power density. Traditional micro gear pumps often use a direct-drive layout where a high-torque motor directly drives the gear pair. To meet the starting and running torque requirements, the motor usually accounts for more than 60% of the total pump system volume, resulting in a "large motor for a small load" phenomenon, which restricts the miniaturization and weight reduction of the entire device. At the same time, the radial dimension of the output shaft is limited by the gear module, making it difficult to further reduce, thus forming a bottleneck in miniaturization design.

[0003] 2. Complex transmission structure and low space utilization. In order to reduce the demand for motor torque, some designs introduce external reduction mechanisms such as planetary gears. Although this can reduce the size of the motor, the reduction mechanism itself occupies radial space (usually more than 40%), and the multi-stage transmission chain increases the axial dimension, resulting in the overall structure being 15%-20% larger than the direct drive solution, failing to achieve a truly compact layout.

[0004] 3. High operating noise and poor dynamic performance. Gear meshing impact, inherent flow pulsation, and hydraulic shock caused by unloading grooves designed to alleviate oil trapping all contribute to the fact that the operating noise of traditional micro gear pumps is generally higher than 65dB(A), making it difficult to meet the requirements of quiet environments such as offices and medical facilities. In addition, the radial force imbalance caused by the pressure difference between the suction and discharge ports is more pronounced after miniaturization, which aggravates shaft and bearing wear, affects service life, and leads to a decrease in volumetric efficiency and insufficient performance stability during long-term operation.

[0005] Therefore, existing micro gear pumps still have significant shortcomings in terms of structural layout, space utilization, noise, and dynamic performance, and cannot meet the urgent needs of the market, requiring further improvement and optimization. Summary of the Invention

[0006] The purpose of this application is to overcome the above-mentioned technical problems and provide a miniature gear pump. Through a unique structural design, it is possible to reduce its size, maintain power density, simplify the transmission structure, improve space utilization, and reduce noise, thereby solving the defects of traditional gear pumps and meeting the urgent needs of the market.

[0007] This application discloses a miniature gear pump, which specifically adopts the following scheme: A miniature gear pump includes: a drive reduction mechanism comprising a motor, a motor housing, a first driving wheel, and a first driven wheel; the drive end of the motor passes through the motor housing for the first driving wheel to be fitted onto; the first driven wheel is located in the motor housing and meshes with the first driving wheel; the meshing mechanism includes a drive shaft, a positioning and sealing assembly, a gear pump housing, a second driving wheel, and a second driven wheel; one end of the drive shaft is located at the end of the first driven wheel away from the motor housing, and the other end sequentially passes through the positioning and sealing assembly and the first driving wheel. The gear pump cavity includes a second driving wheel and a second driven wheel, the second driving wheel meshing with the second driven wheel and both located within the gear pump cavity. The gear pump cavity has a through-flow inlet and outlet channel, and the gear pump cavity has an outlet channeling the outlet channel and an inlet channeling the inlet channel. A pump cover assembly includes a pump cover and a first screw. The pump cover covers the end face of the gear pump cavity away from the motor cavity, and the first screw is used to sequentially pass through the pump cover, the gear pump cavity, and the motor cavity for fixation.

[0008] By adopting the above technical solution, the arrangement of the drive reduction mechanism, meshing mechanism, and pump cover assembly avoids the problems of large system size and low power density caused by the direct-drive layout of high-torque motors in traditional micro gear pumps. The motor drive end passes through the motor cavity for the first drive wheel to be fitted. With the meshing of the first driven wheel and the first drive wheel, power can be distributed more rationally, reducing the proportion of motor volume and facilitating the miniaturization and weight reduction of the entire device. The drive shaft passes through the positioning sealing assembly, the gear pump cavity, and the second drive wheel in sequence. The meshing arrangement of the second drive wheel and the second driven wheel in the gear pump cavity, compared with the traditional design that introduces an external reduction mechanism, avoids the problem of the reduction mechanism occupying radial space and increasing axial size, improves space utilization, and achieves a compact layout. At the same time, this structure can alleviate problems such as gear meshing impact, inherent flow pulsation, and hydraulic shock caused by unloading grooves, reduce operating noise, meet the requirements of quiet scenarios such as offices and medical facilities, and improve the radial force imbalance caused by the pressure difference between the suction and discharge ports, reduce shaft and bearing wear, improve service life and volumetric efficiency, and enhance performance stability.

[0009] Optionally, the meshing mechanism further includes: a driven shaft located in the gear pump cavity for the second driven wheel to be fitted, wherein a first shaft hole is provided in the gear pump cavity, and an exhaust hole is provided at the bottom of the first shaft hole.

[0010] By adopting the above technical solution, the driven shaft is located in the gear pump cavity for the second driven wheel to be fitted, which allows the second driven wheel to rotate stably in the gear pump cavity and ensures the normal transmission of the gear pump. The gear pump cavity is provided with a first shaft hole, which provides an installation position for the driven shaft and ensures the accuracy and stability of the driven shaft installation. The bottom of the first shaft hole is provided with an exhaust hole, which can reduce the gas pressure in the first shaft hole, avoid the gas from hindering the rotation of the driven shaft, and improve the operating efficiency and stability of the gear pump.

[0011] Optionally, the positioning sealing assembly includes an oil-impregnated bearing and a star-shaped seal ring. The oil-impregnated bearing is disposed at the end of the first driven wheel away from the motor and is fitted onto the drive shaft. A groove is provided on the oil-impregnated bearing for receiving one end of the star-shaped seal ring. The other end of the star-shaped seal ring protrudes from the groove and abuts against the second shaft hole in the gear pump cavity through which the drive shaft passes. The contact point between the second shaft hole and the star-shaped seal ring is chamfered to facilitate liquid inflow.

[0012] By adopting the above technical solution, the oil-impregnated bearing is located at the end of the first driven wheel furthest from the motor and is fitted with the drive shaft, which can support and position the drive shaft, ensuring the stability of the drive shaft rotation. The groove on the oil-impregnated bearing accommodates one end of the star-shaped seal, which can make the star-shaped seal installed firmly and not easily displaced. The other end of the star-shaped seal protrudes from the groove and abuts against the second shaft hole in the gear pump cavity through which the drive shaft passes, which can effectively prevent liquid from leaking from the gap between the drive shaft and the second shaft hole, thus achieving a good sealing effect. The contact point between the second shaft hole and the star-shaped seal is chamfered, which facilitates the smooth entry of the solution into the groove of the star-shaped seal. When there is more solution, it can squeeze the seal ring to both sides to seal more tightly. This structure can effectively prevent solution leakage and at the same time prevent the oil-impregnated bearing from rusting when in contact with the solution.

[0013] Optionally, the positioning sealing assembly includes: a U-shaped sealing ring disposed at the end of the first driven wheel away from the motor, for abutting against the second shaft hole in the gear pump cavity through which the drive shaft passes; wherein, a first boss abutting against the U-shaped sealing ring is provided at the contact point between the second shaft hole and the U-shaped sealing ring.

[0014] By adopting the above technical solution, a U-shaped sealing ring is set at the end of the first driven wheel away from the motor, and it abuts against the second shaft hole in the gear pump cavity through which the drive shaft passes. This effectively prevents liquid leakage from the gap between the drive shaft and the gear pump cavity, improving the sealing performance of the micro gear pump. A first boss is set at the contact point between the U-shaped sealing ring and the second shaft hole to enhance the tightness of the contact between the U-shaped sealing ring and the second shaft hole, further improving the sealing effect, ensuring the normal operation of the micro gear pump, and reducing failures and efficiency losses caused by liquid leakage.

[0015] Optionally, the drive shaft is a D-shaped shaft, and the corresponding first driven wheel and second drive wheel are provided with D-shaped slots, wherein the drive shaft is detachably connected to the first driven wheel and the second drive wheel through the D-shaped slots.

[0016] By adopting the above technical solution, the drive shaft adopts a D-shaped shaft and the first driven wheel and the second drive wheel are provided with D-shaped slots, realizing a detachable connection between the drive shaft and the first driven wheel and the second drive wheel. This facilitates the installation, disassembly and maintenance of various components of the micro gear pump. This detachable connection also allows for the individual replacement of damaged components when a component is damaged, reducing maintenance costs. At the same time, the cooperation between the D-shaped shaft and the D-shaped slots can accurately transmit torque, ensuring the stability and reliability of power transmission, enabling the micro gear pump to operate stably.

[0017] Optionally, the gear pump cavity is provided with an integral second boss for the second driven wheel to be fitted; the drive shaft and the first driven wheel are configured as an integral unit.

[0018] By adopting the above technical solution, an integrated second boss is provided inside the gear pump cavity for the second driven wheel to be fitted. This improves the connection stability and integrity between the second boss and the gear pump cavity, reduces assembly errors, and makes the rotation of the second driven wheel smoother, thereby improving the working stability of the micro gear pump. The drive shaft and the first driven wheel are integrated, which reduces the number of parts, simplifies the structure, reduces assembly difficulty and cost, and avoids relative movement and connection gaps between the drive shaft and the first driven wheel. This improves transmission efficiency and power transmission reliability, reduces energy loss, and enhances the performance of the micro gear pump.

[0019] Optionally, the gear pump cavity is provided with a double circular cavity for accommodating the second driving wheel and the second driven wheel respectively, wherein the double circular cavity passes through the water inlet tank and the water outlet tank; a positioning post is provided on one end of the gear pump cavity away from the motor cavity, and a matching positioning hole is provided on the corresponding pump cover.

[0020] By adopting the above technical solution, a double-circular cavity is set in the gear pump cavity, which can respectively accommodate the second driving wheel and the second driven wheel, ensuring that the second driving wheel and the second driven wheel rotate stably in the gear pump cavity; the double-circular cavity connects the inlet tank and the outlet tank, allowing the fluid to flow smoothly between the inlet tank, the double-circular cavity and the outlet tank, realizing continuous fluid delivery; the gear pump cavity is embedded in the matching positioning hole through the positioning pin, and with the insertion of the first screw, it can be firmly assembled with the pump cover.

[0021] Optionally, a third boss is provided at the end of the first driven wheel away from the motor.

[0022] By adopting the above technical solution, the third boss located at the end of the first driven wheel away from the motor can help position the first driven wheel and facilitate assembly.

[0023] Optionally, the drive reduction mechanism further includes a second screw, through which the motor is fixed to one end of the motor cavity away from the gear pump cavity.

[0024] By adopting the above technical solution, the motor is fixed to the end of the motor cavity away from the gear pump cavity using the second screw, which ensures that the motor is stably installed in the drive reduction mechanism of the micro gear pump, guaranteeing the stability of the connection between the motor and the motor cavity, and preventing the motor from shaking or shifting during operation, thereby improving the overall reliability of the micro gear pump structure. This fixing method also facilitates the installation and disassembly of the motor. When the motor fails or needs maintenance, it can be easily replaced or repaired, reducing maintenance costs and difficulties. At the same time, fixing the motor in a suitable position is conducive to the rational layout of the internal space of the micro gear pump, making the entire drive reduction mechanism structure more compact and helping to achieve the miniaturization design goal of the micro gear pump.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The motor adopts a meshing mechanism, with the motor drive end passing through the motor cavity for the first driving wheel to be fitted. The first driving wheel meshes with the first driven wheel, which can reduce the torque requirement of the motor, reduce the size of the motor, solve the problems of large size and low power density of traditional micro gear pump systems, and realize the miniaturization and lightweight of the whole machine. 2. The meshing mechanism has a compact structure and layout, without introducing an external reduction mechanism that occupies significant radial space, thus improving space utilization and solving the problems of complex transmission structure and low space utilization in traditional micro gear pumps, achieving a compact layout; 3. The structural design of this micro gear pump helps to improve operating noise and dynamic performance, avoids the high noise problems caused by gear meshing impact, flow pulsation, hydraulic shock, etc. in traditional micro gear pumps, and at the same time alleviates the problem of radial force imbalance, reduces shaft and bearing wear, improves service life and volumetric efficiency, and solves the problems of high operating noise and poor dynamic performance of traditional micro gear pumps. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural schematic diagram of a micro gear pump disclosed in an embodiment of this application; Figure 2 for Figure 1 A schematic cross-sectional view of a micro gear pump; Figure 3 for Figure 1 A schematic diagram of the exploded structure of a micro gear pump; Figure 4 for Figure 1 A schematic diagram of the exploded structure of a micro gear pump; Figure 5 for Figure 1 A schematic diagram of the exploded structure of a micro gear pump; Figure 6 for Figure 1 A top view schematic diagram of the gear pump cavity in a disclosed micro gear pump; Figure 7 This is a cross-sectional structural schematic diagram of a micro gear pump disclosed in another embodiment of this application; Figure 8 This is a cross-sectional structural schematic diagram of a micro gear pump disclosed in another embodiment of this application.

[0027] Explanation of reference numerals in the attached figures: 10. Drive reduction mechanism; 11. Motor; 12. Motor cavity; 13. First driving wheel; 14. First driven wheel; 141. Third boss; 142. D-shaped slot; 15. Second screw; 20. Engaging mechanism; 21. Drive shaft; 22. Positioning and sealing assembly; 221. Oil-impregnated bearing; 2211. Groove; 222. Star-shaped seal; 223. U-shaped seal; 23. Gear pump cavity; 231. Inlet groove; 232. Outlet... 233. Water tank; 234. Water outlet; 235. Water inlet; 236. First shaft hole; 237. Vent hole; 238. Embedded groove; 239. Second boss; 240. Double circular cavity; 241. Positioning post; 242. First boss; 25. Second driving wheel; 26. Second driven wheel; 27. Driven shaft; 30. Rectangular sealing ring; 40. Pump cover assembly; 41. Pump cover; 411. Positioning hole; 42. First screw. Detailed Implementation

[0028] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0029] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0030] This application mainly adopts motor-driven gear transmission to achieve a compact layout of micro pump, which achieves the effects of reducing size, reducing noise and improving energy efficiency. The following is a more detailed description of this application with reference to the accompanying drawings.

[0031] See Figure 1 and Figure 2 This application provides a micro gear pump, including a drive reduction mechanism 10, a meshing mechanism 20, and a pump cover assembly 40.

[0032] The drive reduction mechanism 10 provides power to the entire micro gear pump, the meshing mechanism 20 reduces and transmits the power from the drive reduction mechanism 10, and the pump cover assembly 40 seals and secures the gear pump cavity 23. This achieves the beneficial effects of making the micro gear pump compact, reducing its size, lowering noise, and improving energy efficiency. This is because the reasonable layout of the drive reduction mechanism 10 avoids the large size problem of traditional high-torque motor direct drive, the multi-stage gear transmission of the meshing mechanism 20 achieves effective power transmission and reduction, and the pump cover assembly 40 ensures the sealing and stability of the pump body.

[0033] See Figure 2 , Figure 3 and Figure 4The drive reduction mechanism 10 includes a motor 11, a motor housing 12, a first driving wheel 13, and a first driven wheel 14. The motor 11 is the power source; one end is the power input terminal, equipped with two metal terminals connected to the positive and negative poles of a DC power supply, respectively. The other end is the drive end (i.e., the power output terminal), equipped with a D-shaped drive shaft for passing through the motor housing 12 to assemble the reduction driving wheel (first driving wheel 13). The motor 11 can be a DC motor or a stepper motor, etc., to meet different power requirements. The motor housing 12 protects the drive end of the motor 11 and the first driving wheel 13, and fixes the motor 11 in place. It can be made of metal, such as aluminum alloy, which has good strength and heat dissipation performance; no specific limitation is made here. See also... Figure 5 The motor 11 can be fixed to the motor cavity 12 by two screws (second screw 15). The first driving wheel 13 is a gear structure, and its material can be engineering plastic, such as polyoxymethylene (POM), which has good wear resistance and self-lubricating properties; no specific limitation is made here. The first driven wheel 14 is located in the motor cavity 12 and meshes with the first driving wheel 13. Through this meshing transmission, the power of the motor 11 is transmitted to the drive shaft 21. The first driven wheel 14 can also be made of engineering plastic, and its module and number of teeth with the first driving wheel 13 are reasonably designed according to the reduction ratio.

[0034] See Figure 2 , Figure 3 and Figure 5 The meshing mechanism 20 includes a drive shaft 21, a positioning seal assembly 22, a gear pump chamber 23, a second drive wheel 25, a second driven wheel 26, and a driven shaft 27. One end of the drive shaft 21 is located at the end of the first driven wheel 14 away from the motor chamber 12, and the other end passes through the positioning seal assembly 22, the gear pump chamber 23, and the second drive wheel 25 in sequence. The driven shaft 27 is located in the gear pump chamber 23 and is used to accommodate the second driven wheel 26, providing stable support for the second driven wheel 26 and making its rotation smoother.

[0035] See also Figure 6The gear pump cavity 23 is provided with a first shaft hole 235 (non-through hole) adapted to the driven shaft 27, and a small hole for venting, namely vent hole 236, is provided at the bottom of the first shaft hole 235. The vent hole 236 is provided to reduce the pressure at the bottom of the first shaft hole 235 to improve the operating stability of the pump. The second driving wheel 25 and the second driven wheel 26 mesh and are both located in the gear pump cavity 23. The gear pump cavity 23 is provided with a double circular cavity 240 to accommodate the second driving wheel 25 and the second driven wheel 26 respectively. The gear pump cavity 23 is provided with an inlet groove 231 and an outlet groove 232 that pass through the double circular cavity 240. An inlet 234 and an outlet 233 are respectively provided at the end of the inlet groove 231 and the outlet groove 232. When the second driving wheel 25 and the second driven wheel 26 rotate, a partial vacuum is formed at the inlet 234, which draws the liquid into the inlet tank 231. Then, the liquid is discharged from the outlet tank 232 and the outlet 233 through the meshing of gears.

[0036] The drive shaft 21 and driven shaft 27 can be made of stainless steel, which has good strength and corrosion resistance. The positioning and sealing assembly 22 serves a positioning and sealing function, and in this embodiment includes an oil-impregnated bearing 221 and a star-shaped seal ring 222. The oil-impregnated bearing 221 is located at the end of the first driven wheel 14 furthest from the motor 11 and is fitted onto the drive shaft 21. The oil-impregnated bearing 221 contains lubricating oil, which lubricates the drive shaft 21 during rotation, reducing friction and wear. The oil-impregnated bearing 221 has a groove 2211 for accommodating one end of the star-shaped seal ring 222. The other end of the star-shaped seal ring 222 protrudes from the groove 2211 and abuts against the second shaft hole 237 through which the drive shaft 21 passes in the gear pump cavity 23 to form a seal, preventing liquid leakage from the second shaft hole 237. The star-shaped seal ring 222 can be made of rubber, which has good elasticity and sealing performance. The contact point between the second shaft hole 237 and the star-shaped seal ring 222 has a chamfer. This chamfer design guides the liquid to flow smoothly into the star-shaped seal ring groove 2211. When there is more liquid, it can compress the seal ring to both sides for a tighter seal. This structure effectively prevents the solution from leaking out of the second shaft hole 237, while also preventing the oil-impregnated bearing 221 from rusting upon contact with the solution.

[0037] See Figure 7 In another embodiment, the positioning sealing assembly 22 may also include a U-shaped sealing ring 223. The U-shaped sealing ring 223 is disposed at the end of the first driven wheel 14 away from the motor 11 and is used to abut against the second shaft hole 237 through which the drive shaft 21 passes in the gear pump cavity 23. A first boss 242 is provided at the contact point between the second shaft hole 237 and the U-shaped sealing ring 223 to abut against the U-shaped sealing ring 223. The two work together to enhance the sealing performance, prevent liquid leakage, and improve the working stability and efficiency of the micro gear pump.

[0038] The gear pump chamber 23 can be made of aluminum alloy, which has good strength and processing performance, and no specific limitation is made here. The second driving wheel 25 and the second driven wheel 26 can be made of the same material as the first driving wheel 13 and the first driven wheel 14, all of which are engineering plastics to reduce cost and noise.

[0039] It is worth mentioning here, see Figure 5 The drive shaft 21 adopts a D-shaped shaft, and the first driven wheel 14 and the second drive wheel 25 are provided with matching D-shaped slots 142, realizing a detachable connection between the drive shaft 21 and the first driven wheel 14 and the second drive wheel 25. This facilitates the installation, disassembly and maintenance of various components of the micro gear pump. This detachable connection also allows for the individual replacement of damaged components when a component is damaged, reducing maintenance costs. At the same time, the cooperation between the D-shaped shaft and the D-shaped slots 142 can accurately transmit torque, ensuring the stability and reliability of power transmission, enabling the micro gear pump to operate stably.

[0040] In another embodiment, see Figure 8 The drive shaft 21 can also be directly integrated with the first driven wheel 14, reducing the number of parts, simplifying the structure, reducing assembly difficulty and cost, and avoiding relative movement and connection gap between the drive shaft 21 and the first driven wheel 14, thereby improving transmission efficiency and power transmission reliability, reducing energy loss, and enhancing the performance of the micro gear pump.

[0041] In another embodiment, see Figure 8 The driven shaft 27 can also be replaced by a second boss 239 that is integrally set directly inside the gear pump cavity 23 for the second driven wheel 26 to be fitted. This can improve the connection stability and integrity between the second boss 239 and the gear pump cavity 23, reduce assembly errors, make the rotation of the second driven wheel 26 more stable, and thus improve the working stability of the micro gear pump.

[0042] See Figure 2 and Figure 3 The pump cover assembly 40 includes a pump cover 41 and a first screw 42. The pump cover 41 covers the end face of the gear pump cavity 23 away from the motor cavity 12. The first screw 42 is used to sequentially pass through the pump cover 41, the gear pump cavity 23, and the motor cavity 12 for fixation. The pump cover 41 can be made of plastic, such as polycarbonate (PC), which has good transparency and strength. The first screw 42 can be made of stainless steel screws to ensure a firm connection. Through the sealing of the pump cover 41 and the fixation of the first screw 42, the sealing and stability of the gear pump cavity 23 are ensured, preventing liquid leakage.

[0043] See Figure 4In order to facilitate the assembly and positioning of the gear pump cavity 23 and the pump cover 41, in this embodiment, a positioning post 241 is provided on the end of the gear pump cavity 23 away from the motor cavity 12, and a matching positioning hole 411 is provided on the corresponding pump cover 41.

[0044] See Figure 2 , Figure 5 and Figure 6 In order to improve the structural sealing performance of the micro gear pump, in this embodiment, the micro gear pump also includes a rectangular sealing ring 30. The rectangular sealing ring 30 is rectangular in shape and is embedded in the end of the gear pump cavity 23 away from the motor cavity 12 and abuts against the pump cover 41. The corresponding gear pump cavity 23 is provided with an embedding groove 238. The pump cover 41 and the gear pump cavity 23 are fixed by four first screws 42 to compress the sealing ring and make them contact each other to achieve static sealing.

[0045] The rectangular sealing ring 30 forms a seal at the connection between the gear pump cavity 23 and the pump cover 41, further ensuring the pump body's sealing performance. This improved sealing structure enhances the reliability and service life of the micro gear pump and reduces maintenance costs. The rectangular sealing ring 30 can be made of rubber, such as nitrile rubber (NBR), which has good elasticity and sealing performance; however, no specific limitation is made here.

[0046] See Figure 7 In order to avoid the transmission part of the drive shaft 21 (D-type shaft) from wobbling during the transmission process, which may affect the transmission performance or even lead to transmission failure, in another embodiment, a third boss 141 is provided at the end of the first driven wheel 14 away from the motor 11. This boss can replace the oil-impregnated bearing 221 to play a positioning role and facilitate the assembly of the first driven wheel 14.

[0047] In another embodiment, the drive shaft 21 and oil-impregnated bearing 221 in the drive reduction mechanism 10 and meshing mechanism 20 can be replaced by a direct drive based on an ultra-low speed motor, and can be directly connected to the second drive wheel 25 for drive, or connected to a simplified integrated gear shaft, thereby achieving zero-speed transmission of power. Of course, no limitation is made here.

[0048] The implementation principle of this embodiment is as follows: After the motor 11 starts, its drive end drives the first driving wheel 13 to rotate. The first driving wheel 13 meshes with the first driven wheel 14, transmitting power to the drive shaft 21. The drive shaft 21 drives the second driving wheel 25 to rotate. The second driving wheel 25 meshes with the second driven wheel 26, allowing liquid to enter the inlet tank 231 from the inlet 234. Then, through the rotation of the gears, the liquid is discharged from the outlet tank 232 and the outlet 233. Throughout the process, the drive reduction mechanism 10, the meshing mechanism 20, and the pump cover assembly 40 work together to realize the liquid delivery function of the micro gear pump. Compared with traditional micro gear pumps, this embodiment reduces the system volume, increases power density, reduces operating noise, and improves dynamic performance and energy efficiency through a reasonable structural layout and multi-stage gear transmission, meeting the stringent requirements of miniaturized equipment for fluid delivery components.

[0049] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A miniature gear pump, characterized in that, include: The drive reduction mechanism (10) includes a motor (11), a motor cavity (12), a first drive wheel (13) and a first driven wheel (14). The drive end of the motor (11) passes through the motor cavity (12) for the first drive wheel (13) to be fitted. The first driven wheel (14) is located in the motor cavity (12) and meshes with the first drive wheel (13). The meshing mechanism (20) includes a drive shaft (21), a positioning and sealing assembly (22), a gear pump chamber (23), a second drive wheel (25), and a second driven wheel (26). One end of the drive shaft (21) is located at the end of the first driven wheel (14) away from the motor chamber (12), and the other end passes through the positioning and sealing assembly (22), the gear pump chamber (23), and the second drive wheel (25) in sequence. The second drive wheel (25) meshes with the second driven wheel (26) and is located in the gear pump chamber (23). The gear pump chamber (23) is provided with a through inlet groove (231) and an outlet groove (232). The gear pump chamber (23) is provided with an outlet (233) through the outlet groove (232) and an inlet (234) through the inlet groove (231). The pump cover assembly (40) includes a pump cover (41) and a first screw (42). The pump cover (41) covers the end face of the gear pump cavity (23) away from the motor cavity (12). The first screw (42) is used to fix the pump cover (41), the gear pump cavity (23) and the motor cavity (12) in sequence.

2. The micro gear pump according to claim 1, characterized in that, The meshing mechanism (20) further includes: a driven shaft (27), located in the gear pump cavity (23), for the second driven wheel (26) to be fitted, and a first shaft hole (235) is provided in the corresponding gear pump cavity (23), and an exhaust hole (236) is provided at the bottom of the first shaft hole (235).

3. The micro gear pump according to claim 1, characterized in that, The positioning and sealing assembly (22) includes an oil-impregnated bearing (221) and a star-shaped seal ring (222). The oil-impregnated bearing (221) is located at the end of the first driven wheel (14) away from the motor (11) and is fitted with the drive shaft (21). A groove (2211) is provided on the oil-impregnated bearing (221) for accommodating one end of the star-shaped seal ring (222). The other end of the star-shaped seal ring (222) protrudes from the groove (2211) and abuts against the second shaft hole (237) in the gear pump cavity (23) through which the drive shaft (21) passes. The contact point between the second shaft hole (237) and the star-shaped seal ring (222) is chamfered to facilitate liquid inflow.

4. The micro gear pump according to claim 1, characterized in that, The positioning sealing assembly (22) includes a U-shaped sealing ring (223), which is disposed at the end of the first driven wheel (14) away from the motor (11) and is used to abut against the second shaft hole (237) of the gear pump cavity (23) through which the drive shaft (21) passes; wherein, a first boss (242) abutting against the U-shaped sealing ring (223) is provided at the contact point between the second shaft hole (237) and the U-shaped sealing ring (223).

5. The micro gear pump according to claim 1, characterized in that, Also includes: A rectangular sealing ring (30) is embedded in the end of the gear pump cavity (23) away from the motor cavity (12) and abuts against the pump cover (41). The gear pump cavity (23) is provided with an embedding groove (238).

6. The micro gear pump according to claim 1, characterized in that, The drive shaft (21) is a D-shaped shaft, and the corresponding first driven wheel (14) and second drive wheel (25) are provided with D-shaped slots (142), wherein the drive shaft (21) and the first driven wheel (14) and the second drive wheel (25) are detachably connected through the D-shaped slots (142).

7. The micro gear pump according to claim 1, characterized in that, The gear pump cavity (23) is provided with an integral second boss (239) for the second driven wheel (26) to be fitted. The drive shaft (21) and the first driven wheel (14) are configured as a single unit.

8. The micro gear pump according to claim 1, characterized in that, The gear pump cavity (23) is provided with a double circular cavity (240) for accommodating the second driving wheel (25) and the second driven wheel (26) respectively, wherein the double circular cavity (240) passes through the water inlet tank (231) and the water outlet tank (232). A positioning post (241) is provided on one end of the gear pump cavity (23) away from the motor cavity (12), and a matching positioning hole (411) is provided on the corresponding pump cover (41).

9. The micro gear pump according to claim 4, characterized in that, The first driven wheel (14) has a third boss (141) at the end away from the motor (11).

10. The micro gear pump according to claim 1, characterized in that, The drive reduction mechanism (10) further includes: The second screw (15) is used to fix the motor (11) to one end of the motor cavity (12) away from the gear pump cavity (23) through the second screw (15).

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