Gear Pumps

Abstract

The present application is applicable to the technical field of liquid pumps, and discloses a gear pump, comprising: a first end cover, a second end cover, a pump body, and a gear assembly. The first end cover comprises a first metal end cover and a first plastic end cover connected to each other. The second end cover comprises a second metal end cover and a second plastic end cover connected to each other. The pump body is provided with a gear hole extending through along a first direction, and the first plastic end cover, the first metal end cover, the pump body, the second metal end cover, and the second plastic end cover are sequentially arranged and connected along the first direction, and the first plastic end cover and the second plastic end cover are sealed at both ends of the gear hole along the first direction to enclose the pump body to form a gear cavity. The gear assembly is provided with a gear set, and the gear set is arranged in the gear cavity. The gear pump of the present application can reduce the manufacturing cost and weight of the gear pump, and the gear cavity and the gears are not easy to wear, which can ensure the stable operation of the gear pump.

Description

Technical Field

[0001] The present application relates to the technical field of liquid pumps, and in particular to a gear pump. Background Art

[0002] Liquid pump is a mechanical device used to transport liquids, which is widely used in various industries. Among them, the gear pump changes the air pressure in the cavity by rotating two meshing gears to suck and discharge liquids.

[0003] In the prior art, in order to ensure the stable operation of the gear pump, the gear pump is generally a metal cylinder, which consumes a lot of metal materials and has a high manufacturing cost. Summary of the invention

[0004] The present application is to provide a gear pump, which aims to solve the technical problem of high cost of gear pumps.

[0005] To achieve the above object, the present application provides a gear pump, comprising:

[0006] A first end cap, the first end cap comprising a first metal end cap and a first plastic end cap connected to each other;

[0007] a second end cap, the second end cap comprising a second metal end cap and a second plastic end cap connected to each other;

[0008] A pump body, wherein the pump body is provided with a gear hole penetrating along a first direction, the first plastic end cap, the first metal end cap, the pump body, the second metal end cap, and the second plastic end cap are sequentially arranged and connected along the first direction, and the first plastic end cap and the second plastic end cap are sealed at both ends of the gear hole along the first direction to enclose the pump body to form a gear cavity;

[0009] The gear assembly is provided with a gear set, and the gear set is arranged in the gear cavity.

[0010] The gear pump of the present application further includes a fastener, which passes through and connects the first plastic end cover, the first metal end cover, the pump body, the second metal end cover and the second plastic end cover.

[0011] In the gear pump of the present application, the thickness ratio of the first metal end cover to the first plastic end cover along the first direction is 1:3.

[0012] In the gear pump of the present application, the thickness ratio of the second metal end cover to the second plastic end cover along the first direction is 1:3.

[0013] In the gear pump of the present application, the gear assembly also includes two gear shafts, the gear set includes two meshing gears, each of the gear shafts is connected to one of the gears, each of the gear shafts is convexly provided with an annular protrusion, each of the gears is provided with a mounting hole, the annular protrusion and the mounting hole are matched and connected so that each of the gears is arranged around the circumferential side of the annular protrusion of the corresponding gear shaft.

[0014] In the gear pump of the present application, each of the gears is molded with rubber on the circumference of the annular protrusion.

[0015] In the gear pump of the present application, a protrusion is provided on the surface of the annular protrusion, and the protrusion is adapted to the inner wall of the mounting hole.

[0016] In the gear pump of the present application, the protrusion includes a plurality of strip knurlings extending along the first direction, and the plurality of strip knurlings and the corresponding plurality of gear teeth of the gear correspond to each other one by one and are arranged relatively to each other.

[0017] In the gear pump of the present application, the diameter ratio of the pitch circle of the gear and the annular protrusion is 2:1.

[0018] In the gear pump of the present application, the first end cover is provided with a liquid inlet channel and a liquid outlet channel, the liquid inlet channel and the liquid outlet channel both pass through the first metal end cover and the first plastic end cover, and the liquid inlet channel and the liquid outlet channel both communicate with the gear cavity.

[0019] The gear pump provided by the present application has a first metal end cap of the first end cap and a second metal end cap of the second end cap arranged at both ends of the pump body along the first direction to form a sealed gear cavity. When the gear rotates in the gear cavity, the flow of the liquid can be guided by suction to achieve pumping liquid. Compared with the prior art, the gear pump of the present application changes the original metal end caps at both ends of the pump body into plastic, and the gear cavity is formed by the first metal end cap, the second metal end cap and the pump body. When the gear pump is running, the contact position between the gear and the first metal end cap and the second metal end cap is smooth, and it is not easy to cause wear to the gear cavity and the gear, which can ensure the stable operation of the gear pump to achieve stable pumping liquid. In addition, there is no need to consume too much metal material, which reduces the manufacturing cost of the gear pump. At the same time, it also reduces the overall weight of the gear pump, which is convenient for users to carry and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0021] Figure 1 It is one of the structural schematic diagrams of the gear pump provided in the embodiment of the present application;

[0022] Figure 2 This is the second structural schematic diagram of the gear pump provided in the embodiment of the present application;

[0023] Figure 3 is a cross-sectional view of a gear pump provided in an embodiment of the present application;

[0024] Figure 4 It is a schematic diagram of the decomposition of the gear pump provided in the embodiment of the present application.

[0025] Description of Figure Numbers:

[0026] a: first direction;

[0027] 10: first end cap; 10a: liquid inlet channel; 10b: liquid outlet channel; 11: first plastic end cap; 12: first metal end cap;

[0028] 20: second end cap; 21: second plastic end cap; 22: second metal end cap;

[0029] 30: pump body; 30a: gear cavity; 30b: gear hole;

[0030] 40: gear assembly; 41: gear shaft; 411: annular protrusion; 4111: protrusion; 42: gear. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0033] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or may be indirectly connected to the other element through an intermediate element.

[0034] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] The gear pump is generally a metal cylinder to ensure that the gear pump has high strength and precision. Specifically, the cylinder of the gear pump includes a pump body and end covers at both ends of the pump body. The end covers at both ends and the pump body enclose a gear cavity for installing the gear. The pump body and the end covers at both ends are made of metal. Alternatively, the cylinder of the gear pump includes an integrally formed pump body and an end cover. The integrally formed pump body structure forms a gear groove. The end cover covers the gear groove to form a gear cavity for installing the gear. The integrally formed pump body and the end cover are both made of metal. It can be understood that the various structures of the metal cylinder of the gear pump are made of metal casting. Therefore, it requires more metal materials and has a higher cost. In addition, the overall weight of the manufactured gear pump is heavy, which is inconvenient to carry and use.

[0036] To this end, an embodiment of the present application provides a gear pump that can reduce the manufacturing cost and weight of the gear pump, and the gear cavity and gears are not easily worn, thereby ensuring the stable operation of the gear pump.

[0037] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0038] like Figures 1 to 3 As shown, the gear pump provided in the embodiment of the present application includes: a first end cover 10 , a second end cover 20 , a pump body 30 and a gear assembly 40 .

[0039] The first end cap 10 includes a first metal end cap 12 and a first plastic end cap 11 connected to each other. The second end cap 20 includes a second metal end cap 22 and a second plastic end cap 21 connected to each other. The pump body 30 is provided with a gear hole 30b extending along the first direction a. The first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22, and the second plastic end cap 21 are sequentially arranged and connected along the first direction a. The first plastic end cap 11 and the second plastic end cap 21 are sealed at both ends of the gear hole 30b along the first direction a to enclose the pump body 30 to form a gear cavity 30a. The gear assembly 40 is provided with a gear set, and the gear set is arranged in the gear cavity 30a.

[0040] It should be noted that the rotating shaft of the gear in the gear cavity 30a is also arranged along the first direction a. The two end faces of the gear 42 along the first direction a are in contact with the first metal end cover 12 and the second metal end cover 22, so that it can be ensured that the liquid will not pass through the gear 42 from the gap between the end face of the gear 42 and the first metal end cover 12 or the second metal end cover 22, thereby ensuring the stable pumping of liquid by the gear pump during operation. It can be understood that during the long-term operation of the gear 42, the first metal end cover 12 and the second metal end cover 22 will be rubbed, and the end cover made of metal material can ensure that the surface in contact with the end faces of the gear 42 is smooth, so as to facilitate the stable rotation of the gear 42 and avoid wear on the end covers at both ends of the pump body 30.

[0041] It should be noted that the gear hole 30b of the pump body 30 is used to accommodate the gear 42, while the first end cover 10 and the second end cover 20 need to accommodate the portion of the gear shaft 41 extending out of the gear 42, or need to be made to form a liquid inlet channel 10a and a liquid outlet channel 10b. Therefore, it is necessary to ensure that the first end cover 10 and the second end cover 20 have a certain thickness. In the present application, the portion of the first end cover 10 and the second end cover 20 that is not in contact with the gear 42 is made of plastic. On the one hand, the proper thickness of the first end cover 10 and the second end cover 20 can be ensured, and on the other hand, the stable operation of the gear can be ensured.

[0042] In the gear pump of the embodiment of the present application, the first metal end cap 12 of the first end cap 10 and the second metal end cap 22 of the second end cap 20 are arranged at both ends of the pump body 30 along the first direction a to form a sealed gear cavity 30a. When the gear 42 rotates in the gear cavity 30a, the flow of the liquid can be guided by suction to achieve pumping liquid. Compared with the prior art, the gear pump of the present application changes the original metal end caps at both ends of the pump body 30 into plastic, and the gear cavity 30a is formed by the first metal end cap 12, the second metal end cap 22 and the pump body 30. When the gear pump is running, the contact position between the gear 42 and the first metal end cap 12 and the second metal end cap 22 is smooth, and it is not easy to cause wear to the gear cavity 30a and the gear 42, which can ensure the stable operation of the gear pump to achieve stable pumping liquid. In addition, there is no need to consume too much metal material, which reduces the manufacturing cost of the gear pump. At the same time, it also reduces the overall weight of the gear pump, which is convenient for users to carry and use.

[0043] Exemplarily, the first metal end cover 12 and the second metal end cover 22 are made of aluminum alloy, stainless steel, etc. The first metal end cover 12 and the second metal end cover 22 made of these materials can ensure the structural strength of the part in contact with the gear 42, and are not easily worn due to the rotation of the gear 42. In addition, these materials also have high corrosion resistance and pressure resistance. After the liquid enters the gear cavity 30a, the gear cavity 30a is not easily corroded and squeezed and deformed by the liquid, which can ensure that the gear pump has a better service life. In the embodiment of the present application, the first metal end cover 12 or the second metal end cover 22 can be integrally formed by melt casting to ensure that the first metal end cover 12 and the second metal end cover 22 have high structural strength, and at the same time, it is also convenient for the subsequent assembly of the gear pump.

[0044] Exemplarily, the material of the first plastic end cap 11 and the second plastic end cap 21 is PPS (polyphenylene sulfide), POK (polyketimide) and other materials. The first plastic end cap 11 and the second plastic end cap 21 of these materials are stable in size, high in hardness, and heat-resistant and wear-resistant. In addition, the first plastic end cap 11 and the second plastic end cap 21 of these materials are low in cost and light in texture, which can reduce the manufacturing cost of the gear pump and reduce the overall weight of the gear pump. At the same time, these materials also have better corrosion resistance, which can ensure that the gear pump has a better service life. In the embodiment of the present application, the first plastic end cap 11 or the second plastic end cap 21 can be integrally formed by injection molding to ensure that the first plastic end cap 11 and the second plastic end cap 21 have higher structural strength, and at the same time, it is also convenient for the subsequent assembly of the gear pump.

[0045] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the first plastic end cap 11 and the second plastic end cap 21 are provided with a hollow portion on the outer side away from the gear cavity 30a. On the basis of ensuring that the first plastic end cap 11 and the second plastic end cap 21 provide sufficient accommodation volume for the gear assembly 40 or the channel, the first plastic end cap 11 and the second plastic end cap 21 can reduce the volume of the first plastic end cap 11 and the second plastic end cap 21 through the hollow portion, so as to save the manufacturing materials of the first plastic end cap 11 and the second plastic end cap 21. Compared with metal materials, the first plastic end cap 11 and the second plastic end cap 21 are easier to manufacture and form the hollow portion, so the manufacturing materials can be further saved and the weight of the gear pump can be reduced.

[0046] In the embodiment of the present application, the pump body 30 is a metal pump body. In this way, the gear cavity 30a formed is a metal gear cavity. When the gear pump is running, the contact position between the gear 42 and the first metal end cover 12 and the second metal end cover 22 is smooth, and it is not easy to cause wear to the gear cavity 30a and the gear 42, which can ensure the stable operation of the gear pump to achieve stable pumping of liquid.

[0047] Exemplarily, the material of the pump body 30 is aluminum alloy, stainless steel, etc. The pump body 30 made of these materials can ensure the structural strength of the part in contact with the gear, and is not easily worn due to the rotation of the gear 42. In addition, these materials also have high corrosion resistance and pressure resistance. After the liquid enters the gear cavity 30a, it is not easy to cause corrosion and extrusion deformation to the gear cavity 30a due to the liquid, which can ensure that the gear pump has a better service life. In the embodiment of the present application, the pump body 30 can be integrally formed by melt casting to ensure that the pump body 30 has a high structural strength, and at the same time, it is also convenient for the subsequent assembly of the gear pump.

[0048] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the gear pump further includes a fastener, which penetrates and connects the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22 and the second plastic end cap 21. Through the fastener, the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22 and the second plastic end cap 21 can be stably connected as a whole, so that the gaps between the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22 and the second plastic end cap 21 are tightly closed, and when the gear pump is running, stable pumping liquid can be ensured without leakage.

[0049] Exemplarily, the fastener includes a fastening screw and a fastening nut. The first plastic end cover 11, the first metal end cover 12, the pump body 30, the second metal end cover 22 and the second plastic end cover 21 are all provided with connected through holes. The fastening screw can pass through the through holes of the first plastic end cover 11, the first metal end cover 12, the pump body 30, the second metal end cover 22 and the second plastic end cover 21, and then the fastening screw is connected by the fastening nut so that the nut and the fastening nut of the fastening screw are respectively abutted against the first plastic end cover 11 and the second plastic end cover 21, so that the first plastic end cover 11, the first metal end cover 12, the pump body 30, the second metal end cover 22 and the second plastic end cover 21 are stably connected and fixed as a whole.

[0050] Exemplarily, a plurality of fasteners are provided to further stably connect and fix the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22, and the second plastic end cap 21 as a whole. For example, four fasteners are provided, which are used to fix the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22, and the second plastic end cap 21 around.

[0051] In the embodiment of the present application, the gear pump further includes a positioning member, and the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22 and the second plastic end cap 21 are all provided with communicating positioning holes. The positioning member is provided through the positioning holes of the first plastic end cap 11, the first metal end cap 12, the pump body 30, the second metal end cap 22 and the second plastic end cap 21. Among them, the positioning holes of the first plastic end cap 11 and the second plastic end cap 21 are blind holes, and the positioning holes of the first metal end cap 12, the pump body 30 and the second metal end cap 22 are through holes. In this way, when assembling the gear pump, the positioning piece can be first passed through the positioning holes of the first plastic end cover 11, the first metal end cover 12, the pump body 30, the second metal end cover 22 and the second plastic end cover 21. Then, when the first plastic end cover 11, the first metal end cover 12, the pump body 30, the second metal end cover 22 and the second plastic end cover 21 are connected by fasteners, it can be ensured that the perforations and other structures of the first plastic end cover 11, the first metal end cover 12, the pump body 30, the second metal end cover 22 and the second plastic end cover 21 are aligned and will not shift, so as to facilitate the assembly and connection of the gear pump.

[0052] like Figure 3 and Figure 4 As shown, in the embodiment of the present application, the first metal end cap 12 is provided with sealing grooves on both surfaces along the first direction a, and the sealing grooves are used to install sealing rings. When connecting the pump body 30, the first metal end cap 12 and the first plastic end cap 11, the sealing rings provided in the sealing grooves on both sides of the first metal end cap 12 can resist the pump body 30 and the first plastic end cap 11 to ensure the sealing of the connection between the pump body 30, the first metal end cap 12 and the first plastic end cap 11. When the gear pump is running, it can ensure stable pumping liquid, not easy to leak, and avoid high-pressure leakage. Exemplarily, the sealing ring is an O-ring to achieve a better sealing effect.

[0053] like Figure 3 and Figure 4 As shown, in the embodiment of the present application, the second metal end cap 22 is provided with sealing grooves on both surfaces along the first direction a, and the sealing grooves are used to install sealing rings. When connecting the pump body 30, the second metal end cap 22 and the second plastic end cap 21, the sealing rings provided in the sealing grooves on both sides of the second metal end cap 22 can resist the pump body 30 and the second plastic end cap 21 to ensure the sealing of the connection between the pump body 30, the second metal end cap 22 and the second plastic end cap 21. When the gear pump is running, it can ensure stable pumping liquid, not easy to leak, and avoid high-pressure leakage. Exemplarily, the sealing ring is an O-ring to achieve a better sealing effect.

[0054] like Figure 3As shown, in the embodiment of the present application, the thickness ratio of the first metal end cap 12 and the first plastic end cap 11 along the first direction a is 1:3. In this way, on the one hand, it can be ensured that the first metal end cap 12 has sufficient structural strength, and on the other hand, it can also be ensured that most of the material of the first end cap 10 is plastic material, so as to greatly reduce the manufacturing cost of the gear pump and reduce the overall weight of the gear pump, so as to facilitate the user to carry and use.

[0055] like Figure 3 As shown, in the embodiment of the present application, the thickness ratio of the second metal end cap 22 and the second plastic end cap 21 along the first direction a is 1:3. In this way, on the one hand, it can be ensured that the second metal end cap 22 has sufficient structural strength, and on the other hand, it can also be ensured that most of the material of the second end cap 20 is plastic material, so as to greatly reduce the manufacturing cost of the gear pump and reduce the overall weight of the gear pump, so as to facilitate the user to carry and use.

[0056] like Figure 3 and Figure 4 As shown, in the embodiment of the present application, the gear assembly 40 also includes two gear shafts 41, and the gear set includes two meshing gears 42, each gear shaft 41 is connected to a gear 42, each gear shaft 41 is convexly provided with an annular protrusion 411, and each gear 42 is provided with a mounting hole, and the annular protrusion 411 and the mounting hole are matched and connected so that each gear 42 is surrounded by the circumference of the annular protrusion 411 of the corresponding gear shaft 41. It can be understood that the gear shaft 41 is a structure used to support the gear 42 to rotate stably in the gear chamber 30a. When the gear pump is running, the two meshing gears 42 will rotate in the gear chamber 30a, and the air pressure on one side of the gear chamber 30a will decrease through continuous rotation, so that the liquid can be sucked, and the liquid will be driven to the other side of the gear chamber 30a under the rotation of the gear teeth of the two gears 42. As the two gears 42 continue to rotate, the air pressure on the other side of the gear chamber 30a increases, and the liquid can be discharged to achieve pumping liquid. It should be noted that the two gears 42 are the core structure of the gear pump. In order to ensure stable pumping of liquid, it is necessary to ensure that they have better mechanical properties, corrosion resistance and high temperature resistance. Therefore, the material cost of manufacturing the gears is relatively high. For example, existing gears are generally made of PEEK (polyetheretherketone), and the gears are generally directly sleeved on the rod body of the gear shaft 41, or the gears and the gear shaft 41 are integrally formed with the same material. In the present application, an annular protrusion 411 is provided on the portion of the gear shaft 41 connecting the gear 42, and cooperates with the mounting hole of the gear 42, so that the material for making the gear 42 itself can be reduced, and the gear shaft 41 can adopt a more commonly used and low-cost material, thereby greatly reducing the overall cost of the gear assembly 40, so as to further reduce the manufacturing cost of the gear pump.

[0057] Exemplarily, the material of the gear 42 is PEEK (polyetheretherketone), so as to ensure that the gear 42 itself has better mechanical properties, corrosion resistance and high temperature resistance, thereby ensuring a better service life of the gear pump.

[0058] Exemplarily, the material of the gear shaft 41 is ceramic, stainless steel, etc. In this way, it can ensure better structural strength and have higher corrosion resistance and pressure resistance. Compared with the material of the gear 42, its cost is lower, so by using the annular protrusion 411 of the gear shaft 41 to make part of the structure of the gear 42, the overall cost of the gear assembly 40 can be greatly reduced.

[0059] In the embodiment of the present application, each gear 42 is molded by rubber encapsulation on the circumference of the annular protrusion 411. The gear 42 is integrally molded with the gear shaft 41 by rubber encapsulation, which can ensure a stable connection between the gear shaft 41 and the gear 42, and at the same time ensure that the surface of the gear 42 and the annular protrusion 411 along the first direction a is neat, so that the gear and the annular protrusion 411 are in smooth contact with the first metal end cover 12 or the second metal end cover 22, and it is not easy to cause wear to the gear cavity 30a and the gear 42, which can ensure the stable operation of the gear pump to achieve stable pumping. Specifically, when molding each gear 42 and the gear shaft 41, the gear shaft 41 can be first molded by melt casting, and then the gear shaft 41 can be placed in an injection mold, and the rubber is encapsulated on the circumference of the annular protrusion 411 of the gear shaft 41 by injection molding, so that the gear and the gear shaft 41 are integrally molded.

[0060] like Figure 4 As shown, in the embodiment of the present application, a protrusion 4111 is provided on the surface of the annular protrusion 411, and the protrusion 4111 is adapted to the inner wall of the mounting hole. Since the protrusion 4111 is adapted to the inner wall of the mounting hole, the protrusion 4111 can be snapped into the recessed portion of the inner wall of the mounting hole, so that the stable connection between the gear and the annular protrusion 411 can be further ensured, so that the gear 42 can stably perform high-intensity rotation.

[0061] like Figure 4 As shown, in some embodiments, the protrusion 4111 includes a plurality of strip knurls extending along the first direction a, and the plurality of strip knurls correspond to and are arranged relative to the plurality of gear teeth of the corresponding gear 42. In this way, on the one hand, the gear 42 and the gear shaft 41 can be stably connected, and when the gear 42 rotates, the gear 42 and the gear shaft 41 can be ensured to rotate synchronously and stably, and the gear 42 is not easy to deviate from the gear shaft 41 along the circumference of the annular protrusion 411. On the other hand, the volume of the annular protrusion 411 can be increased as much as possible, while reducing the volume of the gear itself, so as to further reduce the overall cost of the gear assembly 40.

[0062] In some embodiments, the protrusion 4111 includes a plurality of strip knurls extending along the circumference of the annular protrusion 411. In this way, the gear 42 and the gear shaft 41 can be stably connected, and when the gear 42 rotates, it can be ensured that the gear 42 and the gear shaft 41 rotate synchronously and stably, and the gear 42 is not easy to deviate from the gear shaft 41 along the axial direction of the annular protrusion 411.

[0063] like Figure 4 As shown, in the embodiment of the present application, the ratio of the pitch circle of the gear 42 to the diameter of the annular protrusion 411 is 2: 1. In this way, on the one hand, it can ensure that the gear 42 itself has sufficient mechanical properties, corrosion resistance and high temperature resistance, and on the other hand, the annular protrusion 411 can be made as large as possible to further reduce the overall cost of the gear assembly 40.

[0064] like Figure 1 and Figure 2 As shown, in the embodiment of the present application, the first end cover 10 is provided with a liquid inlet channel 10a and a liquid outlet channel 10b, and the liquid inlet channel 10a and the liquid outlet channel 10b are both connected to the first metal end cover 12 and the first plastic end cover 11, and the liquid inlet channel 10a and the liquid outlet channel 10b are both connected to the gear chamber 30a. When the gear pump is running, the liquid can be sucked from the liquid inlet channel 10a to one side of the gear chamber 30a by the rotation of the gear 42, and the gear 42 brings the liquid to the other side of the gear chamber 30a by the rotation, and the liquid on the other side of the gear chamber 30a is discharged from the liquid outlet channel 10b by the rotation of the gear 42. In the present application, the liquid inlet channel 10a and the liquid outlet channel 10b are arranged on the first end cover 10, which can extend the channel entering the gear chamber 30a, avoid the liquid directly flushing the gear chamber 30a and the gear 42, and can effectively extend the service life of the gear pump. Furthermore, since the first end cap 10 is made of plastic material to form the liquid inlet channel 10a and the liquid outlet channel 10b, the manufacturing cost can be greatly reduced and the weight of the gear pump can be reduced. Of course, in other embodiments, the liquid inlet channel 10a and the liquid outlet channel 10b can also be directly arranged on the side of the pump body 30.

[0065] Exemplarily, the first plastic end cap 11 is provided with a first liquid inlet hole along the first direction a and a second liquid inlet hole along the radial direction, one end of the first liquid inlet hole is connected to one side of the gear cavity 30a, one end of the second liquid inlet hole is connected to the side of the first plastic end cap 11, and the first liquid inlet hole and the second liquid inlet hole are connected to form a partial liquid inlet channel 10a. The second plastic end cap 21 is provided with a third liquid inlet hole along the first direction a and a fourth liquid inlet hole along the radial direction, one end of the third liquid inlet hole is connected to the other side of the gear cavity 30a, one end of the fourth liquid inlet hole is connected to the other side of the first plastic end cap 11, and the third liquid inlet hole and the fourth liquid inlet hole are connected to form a partial liquid outlet channel 10b.

[0066] In the embodiment of the present application, the first plastic end cap 11 and / or the second plastic end cap 21 is provided with at least one bearing to connect at least one end of the two gear shafts 41. In this way, the first plastic end cap 11 and the second plastic end cap 21 can accommodate the part of the gear 42 extending out of the gear set, and the two gears 42 and the gear shaft 41 can be stably and accurately rotated in the pump body 30 through the provided bearings. The end caps made of plastic can greatly reduce the manufacturing cost and reduce the weight of the gear pump.

[0067] In the embodiment of the present application, in the gear assembly 40, one of the two gears 42 is a driving gear and the other is a driven gear. One of the gears 42 can drive the other gear 42 to rotate, so as to realize the gear pump pumping liquid.

[0068] In the embodiment of the present application, the gear pump further includes a motor. In the gear assembly 40, one end of one of the gear shafts 41 extends out of the first plastic end cap 11, and the motor is connected to one of the gear shafts 41. When the gear pump is running, the motor can drive one of the gear shafts 41 to rotate, thereby driving the connected gear 42 to rotate, and the two gears 42 rotate by meshing to achieve pumping liquid.

[0069] Referring to Table 1, it can be seen that, compared with the existing gear pumps, the gear pump of the present application can ensure basic operating efficiency and structural strength, while reducing the manufacturing cost of the gear pump and reducing the overall weight of the gear pump to facilitate user transportation and use.

[0070] Table 1

[0071] name Voltage / V Current / A <![CDATA[Rotational speed / rpm > Flow rate / L Pressure / Mpa All metal gear pump 48.2 20.3 3570 6.0 1.5 Plastic Metal Gear Pump 48.2 21.0 3740 6.0 1.5

[0072] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the application concept of the present application, or directly / indirectly used in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A gear pump, characterized in that: include: A first end cap, the first end cap comprising a first metal end cap and a first plastic end cap connected to each other; a second end cap, the second end cap comprising a second metal end cap and a second plastic end cap connected to each other; A pump body, wherein the pump body is provided with a gear hole penetrating along a first direction, the first plastic end cap, the first metal end cap, the pump body, the second metal end cap, and the second plastic end cap are sequentially arranged and connected along the first direction, and the first plastic end cap and the second plastic end cap are sealed at both ends of the gear hole along the first direction to enclose the pump body to form a gear cavity; The gear assembly is provided with a gear set, and the gear set is arranged in the gear cavity.

2. The gear pump according to claim 1, characterized in that It also includes a fastener, which passes through and connects the first plastic end cover, the first metal end cover, the pump body, the second metal end cover and the second plastic end cover.

3. The gear pump according to claim 1, characterized in that A thickness ratio of the first metal end cap to the first plastic end cap along the first direction is 1:

3.

4. The gear pump according to claim 1, characterized in that A thickness ratio of the second metal end cap to the second plastic end cap along the first direction is 1:

3.

5. The gear pump according to claim 1, characterized in that The gear assembly also includes two gear shafts, and the gear set includes two meshing gears. Each gear shaft is connected to a gear, each gear shaft is convexly provided with an annular protrusion, and each gear is provided with a mounting hole. The annular protrusion and the mounting hole are matched and connected so that each gear is surrounded by the circumferential side of the annular protrusion of the corresponding gear shaft.

6. The gear pump according to claim 1, characterized in that Each of the gears is molded with rubber on the circumference of the annular protrusion.

7. The gear pump according to claim 1, characterized in that A protrusion is provided on the surface of the annular protrusion, and the protrusion is matched with the inner wall of the mounting hole.

8. The gear pump according to claim 1, characterized in that The raised portion includes a plurality of strip knurling patterns extending along the first direction, and the plurality of strip knurling patterns correspond to a plurality of gear teeth of the corresponding gear and are arranged opposite to each other.

9. The gear pump according to claim 1, characterized in that: The diameter ratio of the pitch circle of the gear and the annular protrusion is 2:

1.

10. The gear pump according to claim 1, characterized in that The first end cover is provided with a liquid inlet channel and a liquid outlet channel, the liquid inlet channel and the liquid outlet channel both penetrate the first metal end cover and the first plastic end cover, and the liquid inlet channel and the liquid outlet channel both communicate with the gear cavity.

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