Gear pump body assembly and gear pump

Abstract

The invention discloses a gear pump body assembly, which can normally release pressure even when a working medium is liquid with large viscosity, and comprises a gear pump head, a liquid outlet pipe and a pressure release valve, the pressure release valve is arranged on the gear pump head, the gear pump head comprises a pump seat and a gear pair arranged in the pump seat, the pump seat is internally provided with a liquid inlet side in contact with / close to the liquid, and the liquid outlet pipe is arranged on the liquid inlet side. The pump base is provided with a liquid inlet with an opening in the liquid inlet side, the disengagement side of the gear pair is communicated with the liquid inlet, a liquid drainage flow channel is arranged in the pump base, the pressure relief valve is provided with a first connector and a second connector, one end of the liquid drainage flow channel is communicated with the first connector, the other end of the liquid drainage flow channel is communicated with the meshing side of the gear pair, and the liquid outlet pipe is communicated with the second connector. The pump base is provided with a small flow guide opening which is communicated with the liquid drainage flow channel and is opened in the side face different from the side face where the liquid drainage side is located.

Description

Technical Field

[0001] This invention relates to the field of gear pumps, and more particularly to a gear pump body assembly and a gear pump. Background Technology

[0002] A gear pump is a rotary pump that relies on the change and movement of the working volume formed between the pump cylinder and the meshing gears to transport or pressurize liquids. When the gears rotate, the volume of the space on the disengaged side of the gears increases from small to large, forming a vacuum that draws in the liquid. The space on the meshing side of the gears decreases from large to small, squeezing out the liquid. The suction chamber and the discharge chamber are separated by the meshing line of the two gears. The pressure at the outlet of the gear pump depends entirely on the resistance at the pump outlet.

[0003] In existing technology, the gear meshing side is connected to an output channel, which is used to output liquid. A pressure relief valve is also installed in the output channel to facilitate pressure relief. However, it has been found in production that when the liquid is grease, especially when the grease contains gypsum, the grease has high viscosity and high damping. When the pump stops, the grease has difficulty flowing back to the oil tank through the gear gap. Therefore, the pressure difference across the pressure relief valve is very small (almost equal), so the pressure relief valve cannot be switched to the open position, resulting in the equipment being unable to relieve pressure and directly affecting the normal operation of the pump. Therefore, there is an urgent need for a gear pump body device and gear pump that can also properly relieve pressure when pumping highly viscous liquids to overcome the above-mentioned defects. Summary of the Invention

[0004] The purpose of this invention is to provide a gear pump assembly that can normally release pressure when pumping a highly viscous liquid.

[0005] Another objective of this invention is to provide a gear pump assembly that can normally release pressure when pumping a highly viscous liquid.

[0006] To achieve the above objectives, the gear pump assembly provided by the present invention includes a gear pump head, a liquid outlet pipe, and a pressure relief valve. The pressure relief valve is installed on the gear pump head, which includes a pump base and a gear pair installed within the pump base. The pump base has a liquid inlet side that contacts / is close to the liquid, and the pump base has an inlet port that opens onto the liquid inlet side. The disengaged side of the gear pair communicates with the liquid inlet port. The pump base has a drain channel, and the pressure relief valve has a first interface and a second interface. One end of the drain channel is connected to the first interface, and the other end of the drain channel meshes with the gear pair. The pump base is connected to the second interface. The pump outlet is connected to the second interface. The pump base is provided with a small guide port that is connected to the discharge channel and opens on a side different from the side where the discharge side is located. When the gear pair is running and pumping liquid, the pressure relief valve is closed by the liquid pushing it, so that the first interface and the second interface are connected. When the gear pair stops running, the pressure difference between the second interface and the first interface is established, which causes the pressure relief valve to switch from the closed state to the open state, thereby cutting off the connection between the second interface and the first interface. The liquid remaining in the outlet pipe is discharged outward through the open pressure relief valve.

[0007] Preferably, the inlet side of the pump base is located on the bottom side of the pump base, and the flow guide orifice is located on the peripheral side of the pump base.

[0008] Preferably, the pump base includes an upper plate, an intermediate plate, and a lower plate, which are stacked from top to bottom and fixed to each other. A gear pair is mounted on the intermediate plate. The upper plate has an extension portion that extends radially beyond the intermediate plate along the pump base. The bottom side of the extension portion is located above the liquid inlet side, and a guide orifice is opened on the bottom side of the extension portion.

[0009] Preferably, a shallow channel / channel is provided on the bottom side of the upper piece, and the small opening for guiding the flow is connected to the drainage channel through the shallow channel / channel. The middle piece seals the shallow channel.

[0010] Preferably, the bottom periphery of the lower piece extends downward to form a connecting ring, which encloses a liquid absorption space.

[0011] Preferably, the pump base also includes a filter screen, which is installed on the connecting ring and located in the suction space. The filter screen seals the suction space and is located below the inlet side, with the filter screen spaced apart from the inlet side.

[0012] Preferably, the pressure relief valve includes a housing, a pressure relief connector, a pressure relief spring, and a valve plug. The housing is installed in the drain channel and has a mounting cavity. A first interface and a second interface are respectively opened in the housing and communicate with the mounting cavity. The pressure relief connector is fixedly installed in the mounting cavity. The valve plug is axially slidably installed in the mounting cavity. The pressure relief spring is located between the pressure relief connector and the valve plug. The pressure relief spring always has a tendency to drive the valve plug away from the pressure relief connector. The pressure relief connector has a pressure relief channel. One end of the pressure relief channel opens into the mounting cavity and the other end opens outward. When the pressure relief valve is in the closed state, the valve plug is pushed against the pressure relief connector, cutting off the communication between the pressure relief channel and the mounting cavity. The valve plug also contracts, forming a gap between its outer periphery and the inner wall of the mounting cavity, connecting the first interface and the second interface. When the pressure relief valve is in the open state, the valve plug is pushed away from the pressure relief connector by the pressure relief spring, connecting the mounting cavity and the pressure relief channel. The valve plug also unfolds, pressing its outer periphery against the inner wall of the mounting cavity, cutting off the communication between the first interface and the second interface.

[0013] Preferably, one end of the valve plug has an umbrella-shaped skirt and a plug structure. The umbrella-shaped skirt is arranged to surround the plug structure. When the valve plug contracts, the umbrella-shaped skirt closes and approaches the plug structure. When the valve plug expands, the umbrella-shaped skirt expands and moves away from the plug structure. The valve plug is pressed against the pressure relief connector by the plug structure, thereby cutting off the connection between the pressure relief channel and the installation cavity.

[0014] Preferably, the mounting cavity is provided with a sliding space, the valve plug is axially slidably inserted into the sliding space, and the pressure relief spring is respectively fitted onto the pressure relief connector and the plug structure.

[0015] To achieve another objective mentioned above, the present invention also provides a gear pump comprising an electric drive module, a support base, a drive shaft, a hanger, an oil tank, and the aforementioned gear pump assembly. The upper end of the hanger is mounted on the support base, the gear pump head is mounted on the lower end of the hanger, the electric drive module is mounted on the support base and positioned above it, the drive shaft passes through the hanger, one end of the drive shaft is connected to the output end of the electric drive module, and the other end of the drive shaft is connected to the input end of the gear pair, the oil tank is mounted on the support base and positioned below it, and the gear pump assembly is disposed within the oil tank.

[0016] Compared with the prior art, the gear pump assembly of the present invention solves different technical problems and brings different technical effects when used for pumping grease and thin oil.

[0017] When pumping grease, grease remains in the outlet pipe and drain channel when the gear pair stops operating. Due to the grease's high viscosity, it is difficult for it to flow back through the gear pair gaps to the inlet and ultimately back into the oil tank. Even if it eventually flows back, the process is time-consuming. This invention addresses this by creating a small guide orifice on the pump base, not on the side of the inlet, and connecting it to the drain channel. Grease in the drain channel can be discharged through this guide orifice, minimizing or eliminating the need for backflow through the gear pair gaps. This allows the pressure in the drain channel to drop quickly, establishing a pressure difference between the outlet pipe and the drain channel, enabling the pressure relief valve to switch normally from closed to open. Grease in the outlet pipe is then discharged through the pressure relief valve, ensuring proper pressure relief. It is worth noting that the guide orifice refers to a small opening with a cross-sectional area of ​​approximately 0.01 mm. 2 ~5mm 2 Depending on the equipment, the diameter of the guide orifice will vary. The guide orifice should not be made too large to avoid a significant portion of the grease overflowing through an excessively large opening during normal pressure pumping. Furthermore, because the guide orifice has a small diameter, the amount of grease flowing out during normal pressure pumping is minimal and will not affect normal pumping operation.

[0018] When pumping thin oil, at the moment the equipment starts, air often accumulates near the inlet side instead of thin oil. Therefore, the air near the inlet side is pumped out first. The air is first sucked into the disengaged side of the gear pair through the inlet, and then ejected to the meshing side of the gear pair. Since the drain channel is connected to the meshing side, and the guide port is connected to the drain channel, the air cannot flow through the pressure relief valve at the moment the equipment starts, that is, it cannot flow from the first port to the second port. The pumped air can only flow through the drain channel and then out through the guide port, realizing the venting during the start-up phase. Also, because the guide port is not located on the side where the inlet side is located, the air will not flow back to the inlet side. After the venting is completed, the thin oil is drawn in and then pumped out to the meshing side of the gear pair. It then flows through the drain channel. At this time, the oil has considerable pressure, which opens the pressure relief valve, causing the pressure relief valve to switch from the open state to the closed state. The thin oil flows from the first port to the second port and finally flows into the outlet pipe, thus realizing the oil pumping. Attached Figure Description

[0019] Figure 1 This is a perspective view of the gear pump of the present invention with the oil tank concealed.

[0020] Figure 2 yes Figure 1 The image shows a three-dimensional view of the gear pump at another angle.

[0021] Figure 3This is a perspective view of the gear pump of the present invention after concealing the electric drive module, support base and oil tank.

[0022] Figure 4 yes Figure 3 The structure shown is a three-dimensional view after separation from the pressure relief valve.

[0023] Figure 5 yes Figure 3 The structure shown is a three-dimensional view when viewed from another angle.

[0024] Figure 6 yes Figure 3 The structure shown is a three-dimensional view after being separated from the pump base.

[0025] Figure 7 yes Figure 3 The left view of the structure shown.

[0026] Figure 8 yes Figure 7 The structure shown along Figure 7 The sectional view obtained after cutting the EE line segment.

[0027] Figure 9 yes Figure 8 An enlarged schematic diagram of the structure at point P, where the pressure relief valve is in the open position.

[0028] Figure 10 This is an enlarged schematic diagram of the structure at point P when the pressure relief valve is in the closed state.

[0029] Figure 11 This is an exploded perspective view of the liquid outlet pipe and pressure relief valve of the present invention.

[0030] Figure 12 This is a perspective view of the gear pump head of the present invention when it is separated from the upper plate.

[0031] Figure 13 yes Figure 12 The image shows a three-dimensional view of the gear pump head at another angle.

[0032] Figure 14 yes Figure 8 Enlarged schematic diagram of the structure at point F.

[0033] Figure 15 This is a structural diagram of the gear pump head of the present invention, with the upper part transparently displayed. Detailed Implementation

[0034] To illustrate the technical content and structural features of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0035] This invention discloses a gear pump assembly 100 for pumping liquids, which can be oil, alcohol, chemical reagents, water, etc. This invention is illustrated using oil as an example; the oil can be grease with a certain viscosity, or it can be used to pump thin oil (with lower viscosity).

[0036] like Figures 3 to 15 As shown, the gear pump assembly 100 of the present invention includes a gear pump head 10, a liquid outlet pipe 20, and a pressure relief valve 30. The pressure relief valve 30 is installed on the gear pump head 10. The gear pump head 10 includes a pump base 11 and a gear pair 12 installed in the pump base 11. The pump base 11 has an inlet side 111 that is in contact with or close to the liquid. The pump base 11 has an inlet port 112 that opens into the inlet side 111, and the disengagement side A of the gear pair 12 communicates with the inlet port 112. The pump base 11 has a drain channel 113, and the pressure relief valve 30 has a first interface 31 and a second interface 32. One end of the drain channel 113 is connected to the first interface 31, and the other end of the drain channel 113 is connected to the meshing side B of the gear pair 12. The drain channel 113 is a closed channel with only two openings. The pump base 11 is provided with a small guide port 114 that is connected to the drain channel 113 and opens on a side that is different from the side where the inlet side 111 is located.

[0037] The pressure relief valve 30 is closed when the gear pair 12 is running and pumping liquid, due to the pressure push of the liquid (at this time, the state is as follows). Figure 10 As shown), the first interface 31 and the second interface 32 are connected. Grease is drawn in from the inlet 112, then drawn to the disengagement side A, and then pumped out from the meshing side B of the gear pair 12. The grease flows into the drain channel 113, and then flows through the first interface 31 and the second interface 32, and finally flows into the outlet pipe 20 for grease dispensing.

[0038] When gear pair 12 stops operating, a pressure difference is established between the second port 32 and the first port 31, causing the pressure relief valve 30 to switch from the closed state to the open state, thereby cutting off the connection between the second port 32 and the first port 31. The liquid remaining in the outlet pipe 20 is discharged outward through the open pressure relief valve 30 (at this time, the state is as follows). Figure 8 and Figure 9 (As shown).

[0039] The gear pump assembly 100 of the present invention can be used to pump viscous greases, specifically greases with thickeners such as gypsum, but is not limited thereto. Greases have high viscosity due to the presence of particulate matter, which also makes them difficult to pass through small gaps and the gaps in the gear pair to flow back into the oil tank. Furthermore, the gear pump assembly 100 of the present invention can also be used to pump thin oils. Compared to the greases mentioned above, thin oils have lower viscosity, better fluidity, and contain little or no particulate matter.

[0040] The gear pump assembly 100 of the present invention solves different technical problems when used for pumping grease and thin oil, which will be explained separately below. The following description will first focus on grease, followed by thin oil.

[0041] When the pumped material is grease, when the gear pair 12 stops operating, grease remains in the outlet pipe 20 and the drain channel 113. Because grease has a considerable viscosity and is difficult to pass through the gap of the gear pair ( Figure 15 The oil flows back to the inlet 112 via paths M and N, and eventually back to the oil tank. Even if there is an opportunity for it to flow back, it takes a long time. This invention addresses this by creating a small guide orifice 114 on the pump base 11. The guide orifice 114 is not located on the side of the inlet 111, and it connects to the drain channel 113. The grease in the drain channel 113 can be discharged through the guide orifice 114. Figure 14 The grease flows back along path G (avoiding or minimizing paths M and N), causing a rapid decrease in pressure in the drain channel 113. This allows a pressure difference to be established between the outlet pipe 20 and the drain channel 113, enabling the pressure relief valve 30 to switch normally from the closed to the open state. The grease in the outlet pipe 20 is then discharged through the pressure relief valve 30, ensuring normal pressure relief. It is worth noting that the guide orifice 114 refers to a small-diameter opening with a cross-sectional area of ​​approximately 0.01 mm². 2 ~5mm 2 Depending on the equipment, the diameter of the orifice will vary. The guide orifice 114 should not be made too large to avoid a significant portion of the grease flowing out through an oversized opening during normal pressure pumping. In addition, because the diameter of the guide orifice 114 is small, the amount of grease flowing out of the guide orifice 114 during normal pressure pumping is very small and will not affect normal oil pumping.

[0042] When pumping thin oil, at the moment the equipment starts, air often accumulates near the inlet side 111 instead of thin oil. Therefore, the air near the inlet side 111 is pumped out first. The air is first sucked into the disengaged side A of the gear pair 12 through the inlet 112, and then ejected to the meshing side B of the gear pair 12. Since the drain channel 113 is connected to the meshing side B, and the guide port 114 is connected to the drain channel 113, the pressure relief valve 30 is still open at the moment the equipment starts, so the air cannot flow through the pressure relief valve 30, that is, it cannot flow from the first port 31 to the second port 32. The pumped air can only flow through the drain channel 113 and then out through the guide port 114, realizing the exhaust during the start-up phase. Also, since the guide port 114 is not located on the side where the inlet side 111 is located, the air will not flow back to the inlet side 111. After the venting is completed, the thin oil is drawn in and then pumped out to the meshing side B of the gear pair 12. It then flows through the drain channel 113. At this time, the oil has considerable pressure, which opens the pressure relief valve 30, causing the pressure relief valve 30 to switch from the open state to the closed state. The thin oil flows from the first port 31 to the second port 32 and finally flows into the outlet pipe 20, thus realizing the oil pumping.

[0043] As can be seen from the above, when the gear pump assembly 100 of the present invention can pump thin oil without the need for an exhaust valve, the guide port 114 can act as an exhaust valve, allowing the pumped air to flow out.

[0044] like Figures 3 to 10 , Figures 12 to 15 As shown, the pump base 11 includes an upper plate 115, an intermediate plate 116, and a lower plate 117. The upper plate 115, intermediate plate 116, and lower plate 117 are stacked from top to bottom and fixed to each other. A gear pair 12 is mounted on the intermediate plate 116. The upper plate 115 has an extension portion 1151 that extends radially beyond the intermediate plate 116 along the pump base 11. The bottom side of the extension portion 1151 is located above the inlet side 111, and a guide orifice 114 is opened on the bottom side of the extension portion 1151. This design ensures that the inlet side 111 and the guide orifice 114 are not coplanar, and air and oil discharged from the guide orifice 114 will not flow directly to the inlet side 111. The structure of the gear pair 12 is well known to those skilled in the art, and includes a pair of meshing gears.

[0045] Depending on the actual application requirements, the following implementation methods can also be adopted. The liquid inlet side 111 of the pump base 11 is located on the bottom side surface of the pump base 11, and the flow guide orifice 114 is opened on the circumferential side surface of the pump base 11. In this case, the liquid inlet side 111 and the flow guide orifice 114 are not coplanar. In addition, the flow guide orifice 114 can also be opened on the middle plate 116, or on the lower plate 117.

[0046] like Figure 8 , Figure 12 , Figure 13 and Figure 14 As shown in the embodiment provided by the present invention, a shallow channel 1152 is formed on the bottom side of the upper piece 115. The small channel opening 114 is connected to the drain channel 113 through the shallow channel 1152. The middle piece 116 seals the shallow channel 1152. The shallow channel 1152 refers to a channel structure with a small depth, approximately 0.01~0.5mm, and a width of approximately 1~3mm, to limit the flow rate of grease and avoid affecting normal oiling.

[0047] Depending on actual needs, flow channels (not shown in the figure) can also be set on the upper piece 115, the middle piece 116, or the lower piece 117. The flow channel 114 is connected to the drain channel 113 via the flow channel. The difference between the flow channel and the shallow flow channel 1152 is that the flow channel does not have an opening.

[0048] like Figures 1 to 8 , Figure 12 , Figure 13 and Figure 15 As shown, a connecting ring 1171 extends downward from the bottom periphery of the lower plate 117, forming a liquid suction space 1172. During liquid suction, grease flows into the liquid suction space 1172. When adding oil, air is also confined within the liquid suction space 1172. Furthermore, a filter screen (not shown) is also included on the pump base 11. The filter screen is installed on the connecting ring 1171 and located within the liquid suction space 1172, sealing the liquid suction space 1172. The filter screen is located below the liquid inlet side 111, spaced apart from it.

[0049] like Figures 3 to 11 As shown, the pressure relief valve 30 includes a housing 33, a pressure relief connector 34, a pressure relief spring 35, and a valve plug 36. The housing 33 is installed in the drain channel 113. The housing 33 has a mounting cavity 331, with a first interface 31 and a second interface 32 respectively opened in the housing 33 and communicating with the mounting cavity 331. The pressure relief connector 34 is fixedly installed in the mounting cavity 331, and the valve plug 36 is axially slidably installed in the mounting cavity 331. The pressure relief spring 35 is disposed between the pressure relief connector 34 and the valve plug 36, and the pressure relief spring 35 always has a tendency to drive the valve plug 36 away from the pressure relief connector 34. The pressure relief connector 34 has a pressure relief channel 341, one end of which opens into the mounting cavity 331 and the other end opens outward.

[0050] When the pressure relief valve 30 is closed, the valve plug 36 is pushed against the pressure relief connector 34, cutting off the connection between the pressure relief channel 341 and the mounting cavity 331. Oil cannot flow out of the pressure relief channel 341, and the valve plug 36 contracts, creating a gap between its outer circumference and the inner wall of the mounting cavity 331, connecting the first port 31 and the second port 32. Oil flows from the first port 31 to the second port 32 and is finally ejected. The state at this time is as follows: Figure 10 As shown.

[0051] When the pressure relief valve 30 is in the open state, the valve plug 36 is pushed away from the pressure relief connector 34 by the pressure relief spring 35, connecting the mounting cavity 331 and the pressure relief channel 341. The valve plug 36 unfolds so that its outer circumference is pressed tightly against the inner wall of the mounting cavity 331, cutting off the connection between the first interface 31 and the second interface 32. The oil remaining in the outlet pipe 20 flows into the open pressure relief valve 30 through the second interface 32 and is finally discharged, achieving backflow. The state at this time is as follows: Figure 9 .

[0052] like Figure 8 , Figure 9 and Figure 10 As shown, the valve plug 36 has an umbrella-shaped skirt 361 and a plug structure 362. The umbrella-shaped skirt 361 surrounds the plug structure 362, and closes to the plug structure 362 when the valve plug 36 contracts. When the valve plug 36 expands, the umbrella-shaped skirt 361 moves away from the plug structure 362. The valve plug 36 is pressed against the pressure relief connector 34 by the plug structure 362, thereby cutting off the communication between the pressure relief channel 341 and the mounting cavity 331. The mounting cavity 331 is provided with a sliding space 332, and the valve plug 36 is axially slidably inserted into the sliding space 332. The pressure relief spring 35 is respectively fitted onto the pressure relief connector 34 and the plug structure 362 to enhance the installation stability of the pressure relief spring 35.

[0053] like Figure 1 , Figure 2 and Figure 3 As shown, the present invention also provides a gear pump 1000, which includes the aforementioned gear pump body assembly 100, electric drive module 200, support base 300, drive shaft 400, hanger 500, and oil tank (not shown). The upper end of the hanger 500 is mounted on the support base 300, the gear pump head 10 is mounted on the lower end of the hanger 500, the electric drive module 200 is mounted on the support base 300 and located above the support base 300, the drive shaft 400 passes through the hanger 500, one end of the drive shaft 400 is connected to the output end of the electric drive module 200, and the other end of the drive shaft 400 is connected to the input end of the gear pair 12, the oil tank is mounted on the support base 300 and located below the support base 300, and the gear pump body assembly 100 is disposed in the oil tank.

[0054] like Figures 1 to 8As shown, an overflow pressure regulating valve 40 is also installed on the outer casing 33, and the overflow pressure regulating valve 40 is connected to the mounting cavity 331. A one-way valve 37 is installed in the pressure relief channel 341. The one-way valve 37 opens when the machine stops, allowing grease to flow out through the pressure relief channel 341. The one-way valve 37 has no limiting switch state when the pump is pressurized, because at this time the plug structure 362 has cut off the connection between the pressure relief channel 341 and the mounting cavity 331.

[0055] The following is a brief description of the operation of the gear pump 1000 of the present invention, using grease as the pumping medium. However, it should be understood that the pumping medium is not limited to grease; it can also be thin oil, or other viscous or non-viscous liquids. Grease is stored in the oil tank. The electric drive module 200 drives the drive shaft 400 to rotate, which in turn drives the gear pair 12. The space on the disengagement side A of the gear pair 12 increases in size. Liquid near the inlet side 111 is drawn into the inlet port 112, and then grease is forced out to the engagement side B. The grease then flows to the drain channel 113 and then through the first port 31. At this time, the drain channel 113 is pressurized. The flow of grease causes the umbrella-shaped skirt 361 of the valve plug 36 to contract and push the valve plug 36 to slide closer to the pressure relief connector 34. The plug structure 362 presses against the pressure relief connector 34, cutting off the connection between the mounting cavity 331 and the pressure relief channel 341. The grease then flows through the second port 32 and into the outlet pipe 20, pumping the grease out. The state is as follows. Figure 10 As shown. When the electric drive module 200 is powered off (shut down), the gear pair 12 stops operating, and the grease remaining in the drain channel 113 is discharged out through the guide port 114. After a certain amount has flowed out, a pressure difference is established between the second port 32 and the first port 31. The pressure relief spring 35 pushes the valve plug 36 to slide away from the pressure relief connector 34, and the umbrella-shaped skirt 361 of the valve plug 36 opens, cutting off the connection between the second port 32 and the first port 31. The mounting cavity 331 is connected to the pressure relief channel 341, and the grease in the outlet pipe 20 flows into the mounting cavity 331 and then into the pressure relief channel 341, finally flowing out and returning to the oil tank, as shown. Figure 9 As shown.

[0056] The above-disclosed examples are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are within the scope of the present invention.

Claims

1. A gear pump body assembly, characterized in that, The system includes a gear pump head, a discharge pipe, and a pressure relief valve. The pressure relief valve is installed on the gear pump head. The gear pump head includes a pump base and a gear pair installed within the pump base. The pump base has an inlet side that contacts / is close to the liquid. The pump base has an inlet port opening onto the inlet side. The disengaged side of the gear pair communicates with the inlet port. The pump base has a discharge channel. The pressure relief valve has a first interface and a second interface. One end of the discharge channel is connected to the first interface, and the other end of the discharge channel is connected to the meshing side of the gear pair. The discharge pipe is connected to the second interface. The interface is connected, and the pump base is provided with a small guide port that is connected to the discharge channel and opens on a side different from the side where the discharge side is located. When the gear pair is running and pumping liquid, the pressure relief valve is in the closed state due to the liquid pushing it, so that the first interface and the second interface are connected. When the gear pair stops running, the second interface and the first interface establish a pressure difference, causing the pressure relief valve to switch from the closed state to the open state, thereby cutting off the connection between the second interface and the first interface. The liquid remaining in the discharge pipe is discharged outward through the open pressure relief valve.

2. The gear pump assembly according to claim 1, characterized in that, The inlet side of the pump base is located on the bottom side of the pump base, and the guide orifice is located on the peripheral side of the pump base.

3. The gear pump assembly according to claim 1, characterized in that, The pump base includes an upper plate, an intermediate plate, and a lower plate. The upper plate, the intermediate plate, and the lower plate are stacked from top to bottom and fixed together. The gear pair is mounted on the intermediate plate. The upper plate has an extension portion that extends radially beyond the intermediate plate along the pump base. The bottom side of the extension portion is located above the liquid inlet side. The guide orifice is opened on the bottom side of the extension portion.

4. The gear pump assembly according to claim 3, characterized in that, A shallow channel / channel for guiding flow is provided on the bottom side of the upper piece. The small opening for guiding flow is connected to the drainage channel through the shallow channel / channel. The middle piece seals the shallow channel for guiding flow.

5. The gear pump assembly according to claim 3, characterized in that, The bottom periphery of the lower piece extends downward to form a connecting ring, which encloses a liquid absorption space.

6. The gear pump assembly according to claim 5, characterized in that, The pump base also includes a filter screen, which is installed on the connecting ring and disposed in the liquid suction space. The filter screen seals the liquid suction space and is located below the liquid inlet side, with the filter screen spaced apart from the liquid inlet side.

7. The gear pump assembly according to claim 1, characterized in that, The pressure relief valve includes a housing, a pressure relief connector, a pressure relief spring, and a valve plug. The housing is installed in the drainage channel and has a mounting cavity. The first interface and the second interface are respectively opened in the housing and communicate with the mounting cavity. The pressure relief connector is fixedly installed in the mounting cavity. The valve plug is axially slidable in the mounting cavity. The pressure relief spring is disposed between the pressure relief connector and the valve plug, and the pressure relief spring always has a tendency to drive the valve plug away from the pressure relief connector. The pressure relief connector has a pressure relief channel, one end of which opens into the mounting cavity. The other end opens outward. When the pressure relief valve is in the closed state, the valve plug is pushed against the pressure relief connector, cutting off the communication between the pressure relief channel and the mounting cavity. The valve plug retracts, forming a gap between its outer periphery and the inner wall of the mounting cavity, connecting the first interface and the second interface. When the pressure relief valve is in the open state, the valve plug is pushed away from the pressure relief connector by the pressure relief spring, connecting the mounting cavity and the pressure relief channel. The valve plug unfolds, pressing its outer periphery against the inner wall of the mounting cavity, cutting off the communication between the first interface and the second interface.

8. The gear pump assembly according to claim 7, characterized in that, One end of the valve plug has an umbrella-shaped skirt and a plug structure. The umbrella-shaped skirt is arranged to surround the plug structure. When the valve plug contracts, the umbrella-shaped skirt closes and approaches the plug structure. When the valve plug expands, the umbrella-shaped skirt expands and moves away from the plug structure. The valve plug is pressed onto the pressure relief connector by the plug structure, thereby cutting off the communication between the pressure relief channel and the mounting cavity.

9. The gear pump assembly according to claim 8, characterized in that, The mounting cavity is provided with a sliding space, and the valve plug is axially slidably inserted into the sliding space. The pressure relief spring is respectively fitted onto the pressure relief connector and the plug structure.

10. A gear pump, characterized in that, The device includes an electric drive module, a support base, a drive shaft, a mounting bracket, an oil tank, and a gear pump assembly as described in any one of claims 1-9. The upper end of the mounting bracket is mounted on the support base, the gear pump head is mounted on the lower end of the mounting bracket, the electric drive module is mounted on the support base and positioned above it, the drive shaft passes through the mounting bracket, one end of the drive shaft is connected to the output end of the electric drive module, and the other end of the drive shaft is connected to the input end of the gear pair, the oil tank is mounted on the support base and positioned below it, and the gear pump assembly is disposed within the oil tank.

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