A gear pump

Abstract

The utility model provides a gear pump belongs to pump technical field. It solved the gear pump of existing when conveying high viscosity medium, the flow passage inside is easy to have pressure mutation, influence point gum precision, and produce bubble and cause cavitation and noise etc. The gear pump of the utility model includes first pump body, second pump body and third pump body who connects in proper order along the axial direction, is equipped with the pump cavity of accommodating gear pair in second pump body, first pump body is equipped with with the main liquid inlet hole, main liquid outlet hole of pump cavity intercommunication, and with the liquid outlet channel and the back liquid channel who is equipped with pressure valve of main liquid outlet hole intercommunication respectively, back liquid channel still through the liquid inlet channel and the gas outlet channel in third pump body and pump cavity liquid inlet side intercommunication. The utility model has can automatic stabilization output pressure, initiative exclusion bubble, compact structure, reduce medium waste and the advantage that the reliability is high.

Description

Technical Field

[0001] This utility model belongs to the field of pump technology, and specifically refers to a gear pump. Background Technology

[0002] Gear pumps, a common type of positive displacement rotary pump, are widely used in precision processes such as dispensing and gluing in intelligent industrial production due to their compact structure and stable flow rate. Their basic working principle involves a pair of meshing gears rotating within the pump chamber, creating a volume change that allows for the intake and discharge of the medium.

[0003] However, when conveying high-viscosity media such as adhesives and epoxy resins, pressure fluctuations can easily occur inside the flow channels of traditional gear pumps. This not only affects dispensing accuracy but also negatively impacts equipment lifespan. Pressure fluctuations can lead to discontinuous media delivery, the generation of air bubbles, and consequently, cavitation and noise problems.

[0004] In existing technologies, improvements to gear pumps mostly focus on reducing mechanical wear and extending component life. For example, utility model patent CN219587766U discloses a rubber gear pump that uses a support plate and bearings to support the gear shaft, allowing the sealing sleeve to be used for sealing, thereby reducing wear between the gear shaft and the sealing sleeve and improving equipment lifespan. This solution effectively solves the wear problem caused by excessive force on the sealing sleeve, but it does not directly address solutions to key issues such as flow channel pressure stability and air bubble removal. In precision dispensing applications, pressure stability and air bubble management are crucial. If the flow channel pressure cannot be kept stable or air bubbles cannot be removed in time, it will directly affect process quality and the long-term reliability of the pump. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a gear pump. The technical problem this invention aims to solve is how to effectively ensure stable flow channel pressure, actively remove air bubbles, and adapt to the transport of high-viscosity media.

[0006] The objective of this utility model can be achieved through the following technical solution: A gear pump includes a first pump body, a second pump body, and a third pump body that are sequentially and sealed and fixedly connected along the axial direction; a pump chamber is provided through the second pump body along the axial direction, and a gear pair is accommodated in the pump chamber; the first pump body is provided with a main inlet hole coaxially arranged and communicating with the pump chamber, a main outlet hole perpendicular to and communicating with the pump chamber axis, and an outlet channel and a return channel respectively communicating with the main outlet hole; the return channel is also connected to an inlet channel and an outlet channel, the inlet channel and the outlet channel are arranged in the third pump body, and the inlet channel is connected to the inlet side of the pump chamber, and a pressure valve is provided in the return channel.

[0007] This solution actively removes air bubbles mixed in with the medium from the system by incorporating an venting channel within the third pump body connected to the return liquid channel. Continuous or intermittent venting ensures the purity of the medium during pumping, reducing dispensing discontinuities or defects caused by air bubbles, thereby improving the quality of precision processes such as injection and dispensing. A pressure valve within the return liquid channel dynamically adjusts the return flow rate. When the system pressure is too high, the pressure valve opens, diverting some medium from the main outlet to the return liquid channel, and then returning it to the pump inlet side through the inlet channel, forming a pressure buffer. This effectively smooths pressure fluctuations and prevents sudden pressure changes. High-viscosity media easily generate resistance in the flow channel, leading to pressure instability. The introduction of the pressure valve allows the gear pump to automatically compensate for pressure changes, maintaining a stable outlet pressure, thus ensuring the continuity and uniformity of medium delivery and improving dispensing accuracy. Stable pressure reduces the dynamic load on the gear pair and pump body components, reducing wear and fatigue, further improving the reliability and lifespan of the equipment.

[0008] Furthermore, the liquid outlet channel starts from the first pump body and sequentially passes through the second and third pump bodies along the axial direction.

[0009] Furthermore, the liquid outlet channel starts from the main liquid outlet hole, and its outlet extends radially and penetrates to the outer side wall of the first pump body.

[0010] Furthermore, a portion of the liquid outlet channel is located within the second pump body and extends to the outer wall of the second pump body to form an outlet.

[0011] Furthermore, the liquid outlet channel is configured as one or more.

[0012] Furthermore, the return channel includes a first return hole and a second return hole communicating with it; wherein, the first return hole extends in a direction perpendicular to the axis of the main outlet hole, and the second return hole starts from the first return hole and sequentially passes through the second pump body and the third pump body along the axial direction; the pressure valve is disposed in the second return hole.

[0013] Furthermore, the third pump body is also provided with a third return liquid hole; the axis of the third return liquid hole is perpendicular to the axis of the second return liquid hole; the axes of the liquid inlet channel and the air outlet channel are both perpendicular to the axis of the third return liquid hole and are respectively connected to the third return liquid hole; the air outlet channel extends through the third pump body axially from the connection point with the third return liquid hole.

[0014] Furthermore, the third pump body is also provided with a secondary liquid outlet, which is connected to the gas outlet channel and extends radially in a direction perpendicular to the axis of the gas outlet channel, eventually penetrating the outer wall of the third pump body. When the gas in the liquid medium exits from the gas outlet channel, it carries some liquid medium with it. The secondary liquid outlet, located in the middle of the gas outlet channel and extending radially to the outer wall of the third pump body in a direction perpendicular to the axis of the gas outlet channel, can effectively recover the liquid medium there.

[0015] Furthermore, the pressure valve includes a valve body, a valve plate, a valve stem, and a reset element; the valve plate is fixedly connected to the valve stem and housed within the valve body; one axial end of the valve body has an inlet communicating with the first return hole, and its side wall has an outlet communicating with the third return hole; the valve plate is configured to move in response to fluid pressure, overcoming the elastic force of the reset element, to open or close the flow path between the inlet and the outlet.

[0016] Furthermore, the gear pair includes a driving gear and a driven gear, with the driving gear fixedly connected to the driving shaft.

[0017] Compared with existing technologies, the technical advantages of this utility model are as follows: First, by installing a pressure valve in the return liquid channel, an active pressure feedback and regulation system is constructed. When the system pressure is too high, the pressure valve automatically opens to divert the flow, allowing some of the medium to return to the pump inlet side, forming an effective pressure buffer. This smooths out pressure pulsations and sudden changes caused by the transport of high-viscosity media or load variations. It ensures stable outlet pressure, making the medium flow more continuous and uniform in precision dispensing and injection applications, greatly improving process accuracy and product quality consistency. Second, a dedicated air outlet channel is provided, connected to the return liquid system, which can actively and continuously discharge air accumulated inside the system and bubbles precipitated from the medium out of the pump. This avoids bubbles being compressed and instantly bursting in the high-pressure pump chamber, thus protecting the gears and the inner wall of the pump chamber and extending the pump's service life. It also prevents bubbles from being squeezed into the dispensing outlet, causing product defects such as dispensing breaks and insufficient glue. III. A three-body structure, consisting of a first pump body, a second pump body, and a third pump body, is adopted, rationally distributing and connecting the complex inlet, outlet, return, and exhaust channels across different pump bodies. This modular design results in a clear flow channel layout and easier manufacturing. While integrating pressure stabilization and bubble removal functions, it maintains the inherent compact structure of gear pumps, facilitating installation and use in space-constrained automated equipment. IV. A secondary liquid outlet is provided in the exhaust channel to recover small amounts of liquid media carried out during the exhaust process. This reduces waste of high-value media, lowering production costs, and prevents liquid leakage that could contaminate equipment and the environment, maintaining a clean working area. V. Stable pressure reduces impact loads on moving parts such as gear pairs; it also reduces wear and fatigue damage to internal components of the gear pump, improving overall reliability and long-term operational stability, and lowering maintenance frequency and costs. Attached Figure Description

[0018] Figure 1 This is a perspective view of the utility model.

[0019] Figure 2 This is the right view of this utility model.

[0020] Figure 3 This is a cross-sectional view of the present invention.

[0021] Figure 4 This is a BB cross-sectional view of the present invention.

[0022] Figure 5 This is a CC cross-sectional view of this utility model.

[0023] Figure 6 This is a sectional view of the present invention.

[0024] Figure 7 This is a rear view of the present invention.

[0025] Figure 8 This is the front view of this utility model.

[0026] Figure 9 This is a cross-sectional view of the EE of this utility model.

[0027] Figure 10 This is a cross-sectional view of the present invention.

[0028] Drawing number markings: 1. First pump body; 2. Second pump body; 3. Third pump body; 4. Gear pair; 5. Pressure valve; 101. Main inlet port; 102. Main outlet port; 103. Outlet channel; 104. Return channel; 201. Pump chamber; 301. Third return port; 302. Inlet channel; 303. Air outlet channel; 304. Secondary outlet port; 401. Drive gear; 402. Driven gear; 403. Drive shaft; 501. Valve body; 502. Valve plate; 503. Valve stem; 504. Reset component; 1041. First return port; 1042. Second return port; 5011. Inlet; 5012. Outlet. Detailed Implementation

[0029] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0030] It should be noted that the descriptions of directions such as "up," "down," "left," "right," "top," and "bottom" in this utility model are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Figures 1 to 10 As shown, a gear pump includes a first pump body 1, a second pump body 2, and a third pump body 3, which are sequentially and sealedly connected along the axial direction. These three pump bodies are connected by bolts or other fasteners, and sealing rings are provided at the mating surfaces to ensure sealing. A pump chamber 201 is axially extending through the second pump body 2, and a gear pair 4 is housed within the pump chamber 201. The gear pair 4 includes a driving gear 401 and a driven gear 402. The driving gear 401 is fixedly connected to a drive shaft 403, which is driven to rotate by an external motor. The driven gear 402 meshes with the driving gear 401 and rotates within the pump chamber 201 to transport the medium.

[0031] The first pump body 1 is provided with a main inlet hole 101 coaxially arranged and communicating with the pump chamber 201, a main outlet hole 102 perpendicularly arranged and communicating with the axis of the pump chamber 201, and an outlet channel 103 and a return channel 104 respectively communicating with the main outlet hole 102. The main inlet hole 101 is used to draw in the medium, and the main outlet hole 102 is used to discharge the medium. The outlet channel 103 is configured to discharge the medium out of the pump, while the return channel 104 is used for pressure regulation and air bubble removal.

[0032] The liquid outlet channel 103 can be configured in different ways. In one implementation, the liquid outlet channel 103 starts from the main liquid outlet 102 of the first pump body 1, extends radially through the outer wall of the first pump body 1, and directly outputs the medium. In another implementation, a portion of the liquid outlet channel 103 is located within the second pump body 2 and extends to the outer wall of the second pump body 2 to form an outlet. In yet another implementation, the liquid outlet channel 103 starts from the first pump body 1, passes axially through the second pump body 2 and the third pump body 3 sequentially, and forms an outlet on the outer wall of the third pump body 3.

[0033] The liquid outlet channel 103 can be configured as one or more to adapt to different output requirements or spatial layouts.

[0034] The return channel 104 includes a first return hole 1041 and a second return hole 1042 communicating with it. The first return hole 1041 extends in a direction perpendicular to the axis of the main outlet hole 102, and the second return hole 1042 starts from the first return hole 1041 and sequentially passes through the second pump body 2 and the third pump body 3 along the axial direction. A pressure valve 5 is provided in the return channel 104, specifically located in the second return hole 1042.

[0035] The third pump body 3 is also provided with a third return hole 301. The axis of the third return hole 301 is perpendicular to the axis of the second return hole 1042. The axes of the inlet channel 302 and the outlet channel 303 are both perpendicular to the axis of the third return hole 301 and are connected to the third return hole 301 respectively. The inlet channel 302 is connected to the inlet side of the pump chamber 201, which is near the main inlet hole 101. The outlet channel 303 extends axially through the third pump body 3 from its connection with the third return hole 301 to discharge gas outside the pump.

[0036] To recover the liquid medium carried out during the exhaust process, the third pump body 3 is also provided with a secondary liquid outlet 304. The secondary liquid outlet 304 is connected to the exhaust channel 303 and extends radially in a direction perpendicular to the axis of the exhaust channel 303, eventually penetrating the outer wall of the third pump body 3. In this way, when gas is discharged from the exhaust channel 303, the liquid medium carried can be collected by the secondary liquid outlet 304 and returned or discharged, reducing media waste and environmental pollution.

[0037] The pressure valve 5 includes a valve body 501, a valve disc 502, a valve stem 503, and a reset element 504, such as a spring. The valve disc 502 is fixedly connected to the valve stem 503 and housed within the valve body 501. One axial end of the valve body 501 has an inlet 5011 communicating with a first return hole 1041, and its side wall has an outlet 5012 communicating with a third return hole 301. The valve disc 502 is configured to move in response to fluid pressure, overcoming the elastic force of the reset element 504, to open or close the flow path between the inlet 5011 and the outlet 5012. Specifically, when the system pressure is too high, the fluid pressure pushes the valve disc 502 to compress the reset element 504, opening the flow path, and some medium returns from the main outlet 102 to the inlet side of the pump chamber 201 via the return channel 104; when the pressure returns to normal, the reset element 504 pushes the valve disc 502 to reset, closing the flow path.

[0038] The working process of this utility model is as follows: When the drive shaft 403 drives the gear pair 4 to rotate, the medium is drawn into the pump chamber 201 from the main inlet hole 101, and discharged from the main outlet hole 102 after being squeezed by gear meshing. Most of the discharged medium is output to the external system through the outlet channel 103. At the same time, some medium enters the return channel 104. When the system pressure increases due to high viscosity medium or load changes, the pressure valve 5 automatically opens, allowing the medium to return to the inlet side of the pump chamber 201 through the return channel 104 and the inlet channel 302, forming a pressure buffer and stabilizing the output pressure. Air bubbles mixed in the medium accumulate in the return system and are actively discharged through the air outlet channel 303, while the carried liquid is recovered through the secondary outlet hole 304. This ensures the continuity and purity of the medium delivery, improves the dispensing accuracy and equipment life.

[0039] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A gear pump, characterized in that: The system includes a first pump body (1), a second pump body (2), and a third pump body (3) that are sequentially and sealed and fixedly connected along the axial direction. The second pump body (2) has a pump chamber (201) extending through it along the axial direction, and a gear pair (4) is housed within the pump chamber (201). The first pump body (1) has a main inlet hole (101) coaxially arranged and communicating with the pump chamber (201), and a main outlet hole (102) perpendicular to and communicating with the axis of the pump chamber (201). A liquid outlet channel (103) and a liquid return channel (104) are respectively connected to the main liquid outlet (102); the liquid return channel (104) is also connected to a liquid inlet channel (302) and a gas outlet channel (303). The liquid inlet channel (302) and the gas outlet channel (303) are located in the third pump body (3), and the liquid inlet channel (302) is connected to the liquid inlet side of the pump chamber (201). A pressure valve (5) is provided in the liquid return channel (104).

2. A gear pump according to claim 1, characterized in that: The liquid outlet channel (103) starts from the first pump body (1) and passes through the second pump body (2) and the third pump body (3) in sequence along the axial direction.

3. A gear pump according to claim 1, characterized in that: The liquid outlet channel (103) starts from the main liquid outlet (102), and its outlet extends radially and penetrates to the outer side wall of the first pump body (1).

4. A gear pump according to claim 1, characterized in that: A portion of the liquid outlet channel (103) is located inside the second pump body (2) and extends to the outer wall of the second pump body (2) to form an outlet.

5. A gear pump according to any one of claims 1 to 4, characterized in that: The liquid outlet channel (103) is configured as one or more.

6. A gear pump according to claim 1, characterized in that: The return channel (104) includes a first return hole (1041) and a second return hole (1042) connected thereto; wherein, the first return hole (1041) extends in a direction perpendicular to the axis of the main outlet hole (102), and the second return hole (1042) starts from the first return hole (1041) and passes through the second pump body (2) and the third pump body (3) in sequence along the axial direction; the pressure valve (5) is disposed in the second return hole (1042).

7. A gear pump according to claim 6, characterized in that: The third pump body (3) is also provided with a third return hole (301); the axis of the third return hole (301) is perpendicular to the axis of the second return hole (1042); the axes of the inlet channel (302) and the outlet channel (303) are both perpendicular to the axis of the third return hole (301) and are respectively connected to the third return hole (301); the outlet channel (303) extends through the third pump body (3) axially from the connection with the third return hole (301).

8. A gear pump according to claim 7, characterized in that: The third pump body (3) is also provided with a secondary liquid outlet (304), which is connected to the air outlet channel (303) and extends radially in a direction perpendicular to the axis of the air outlet channel (303), and finally penetrates the outer wall of the third pump body (3).

9. A gear pump according to claim 7, characterized in that: The pressure valve (5) includes a valve body (501), a valve plate (502), a valve stem (503), and a reset member (504); the valve plate (502) is fixedly connected to the valve stem (503) and housed within the valve body (501); one axial end of the valve body (501) is provided with an inlet (5011) communicating with the first return hole (1041), and its side wall is provided with an outlet (5012) communicating with the third return hole (301); the valve plate (502) is configured to move in response to fluid pressure, overcoming the elastic force of the reset member (504), so as to open or close the flow path between the inlet (5011) and the outlet (5012).

10. A gear pump according to claim 1, characterized in that: The gear pair (4) includes a driving gear (401) and a driven gear (402), wherein the driving gear (401) is fixedly connected to the driving shaft (403).

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