Externally toothed high-wear-resistant melt gear pump

Abstract

This invention discloses an external meshing high wear-resistant melt gear pump, comprising a pump body. The pump body houses a driving gear, a driven gear, and sliding bearings. The driving gear and the driven gear are integrally formed with the driving shaft, and the sliding bearings are disposed on both sides of the driving and driven gears. A driving helical gear is mounted on the driving shaft, and a driven helical gear is mounted on the driven shaft. The driving and driven helical gears are located in a first bearing housing at one end of the pump body, and a second bearing housing is located at the other end of the pump body. Meshing adjustment mechanisms are provided between the driving helical gear and the driving shaft, and between the driven helical gear and the driven shaft, both located within the first bearing housing. An axial adjustment mechanism for the rotating shaft is provided on the driving and driven shafts, located within the second bearing housing. This invention can reduce gear wear, improve pumping accuracy, and achieve low and stable operation with low noise.

Description

Technical Field

[0001] This invention relates to the field of gear pump technology, and in particular to an external meshing high wear-resistant melt gear pump. Background Technology

[0002] To improve the rigidity of extruded plastic products, reduce shrinkage, and optimize costs, the proportion of high-hardness fillers such as calcium carbonate powder, talc powder, glass fiber, and carbon black in formulations is constantly increasing. However, these high-hardness, high-abrasive fillers pose a severe challenge to the service life and accuracy of melt conveying equipment, especially external meshing melt gear pumps.

[0003] The external meshing melt gear pump has two identical, meshing gears installed inside the pump body. In the feeding zone, the two gears gradually disengage, increasing the volume and drawing the melt into the gear grooves. As the gears rotate, the melt is sealed and transported to the discharge zone. In the discharge zone, the two gears gradually mesh, decreasing the volume and forcibly extruding the melt, achieving pressurized conveying. Thus, the pump gears not only transmit torque but also directly contact the melt containing highly abrasive fillers.

[0004] Increasing the proportion of high-hardness fillers exacerbates wear on the pump gear teeth. Secondly, the pump gears and their sliding bearings on either side have a floating clearance fit. Because the pump gear position is prone to change, the relative movement between them is frequent during operation, and the unstable end-face clearance due to changing stress conditions further intensifies wear between the pump gear end faces and the sliding bearing end faces. These wear mechanisms combined result in a significant decrease in the conveying accuracy and a drastically shortened service life of existing external meshing melt gear pumps, making them unsuitable for long-term stable operation in high-filler material systems. Summary of the Invention

[0005] To address the above problems, this invention provides an external meshing high wear-resistant melt gear pump, specifically employing the following technical solution: The external meshing high wear-resistant melt gear pump of the present invention includes a pump body, in which a driving gear, a driven gear, and a sliding bearing are disposed. The driving gear is integrally formed with the driving shaft, and the driven gear is integrally formed with the driven shaft. The sliding bearing is disposed on both sides of the driving gear and the driven gear. A driving helical gear is disposed on the driving shaft, and a driven helical gear is disposed on the driven shaft. The driving helical gear and the driven helical gear are located in a first bearing housing at one end of the pump body, and a second bearing housing is disposed at the other end of the pump body. A meshing adjustment mechanism is disposed between the driving helical gear and the driving shaft, and between the driven helical gear and the driven shaft, both located in the first bearing housing. An axial adjustment mechanism for the rotating shaft is disposed on the driving shaft and the driven shaft, both located in the second bearing housing.

[0006] This invention uses an axial adjustment mechanism to fix the ends of the drive shaft and driven shaft, thereby fixing the axial position of the pump gears (i.e., the drive gear and driven gear) integrated with them. This, in turn, fixes the gap between the end face of the pump gear and the end face of the sliding bearing, preventing wear due to relative position changes. At the same time, the meshing adjustment mechanism adjusts the meshing fit of the drive helical gear and the driven helical gear, keeping the tooth surface and tooth groove of the pump gear pair in a state of just-contact, reducing the wear of the gear pair during material transmission and improving the pumping accuracy of the gear pump.

[0007] Preferably, the axial adjustment mechanism of the rotating shaft is located outside the first bearing inside the second bearing housing, and includes an external threaded locking nut and an internal threaded locking nut. The external threaded locking nut is used to fix the outer ring of the bearing, and the internal threaded locking nut is used to fix the inner ring of the bearing. Both the external threaded locking nut and the internal threaded locking nut include a radial semi-groove located in the middle of the main body. Coaxial paired threaded holes are provided on both sides of the radial semi-groove. Set screws for changing the pitch of the external threaded locking nut and the internal threaded locking nut are inserted into the paired threaded holes.

[0008] In this invention, the radial half-groove width of the internal and external thread locking nuts is changed by tightening the set screw, so that the pitch of the external thread locking nut does not match the pitch of the internal thread of the bearing housing, and the pitch of the internal thread locking nut does not match the pitch of the external thread of the rotating shaft (i.e., the driving shaft and the driven shaft), thereby achieving the effect of preventing the nut from loosening and achieving the purpose of safely and reliably fixing the inner and outer rings of the bearing.

[0009] Preferably, the central angle of the radial half-groove is 180~270°, and the paired threaded holes are evenly distributed in multiple sets along the circumference of the radial half-groove.

[0010] In this invention, if the radial semi-groove is too small, it is difficult to change the nut pitch; if the radial semi-groove is too large, it affects the structural stability of the nut. Multiple sets of paired threaded holes are arranged circumferentially in the radial semi-groove to enhance the locking effect of the set screw.

[0011] Preferably, an outer ring spacer is provided between the external threaded locking nut and the outer ring of the bearing, and an inner ring spacer is provided between the internal threaded locking nut and the inner ring of the bearing.

[0012] The aforementioned inner and outer ring spacers can be selected with appropriate lengths and radii according to actual needs. They can not only be used to adjust the spacing between the inner and outer threaded locking nuts and the inner and outer rings of the bearings, but also enhance the overall stability of the shaft axial adjustment mechanism.

[0013] Preferably, the first bearing housing is a through-cover bearing housing, including a second bearing located inside the housing and a third bearing located on the pressure plate. An elastic retaining ring for a hole located inside the bearing housing is provided on the outside of the second bearing, or the axial adjustment mechanism of the rotating shaft is provided inside the bearing housing to replace the elastic retaining ring.

[0014] When both the first and second bearings employ axial adjustment mechanisms on their outer sides, adjustment can be made from both ends to change the clearance between the pump gear end face and the sliding bearing end face. This adjustment method is more convenient and flexible to operate, and can increase the axial load-bearing capacity.

[0015] Preferably, the meshing adjustment mechanism is provided with a first gear spacer disposed inside the driving helical gear and the driven helical gear, and a second gear spacer disposed outside the driving helical gear and the driven helical gear, wherein the second gear spacer is provided with the internally threaded locking nut on its outer side.

[0016] In this invention, the driving helical gear and the driven helical gear are connected to the corresponding rotating shaft by a flat key. Due to machining errors, gear phase deviation may occur during torque transmission, resulting in failure to mesh properly. Therefore, a first gear spacer is used to adjust the axial position of the helical gear, and the position is fixed by an internal thread lock nut, so that the helical gear pair can mesh perfectly.

[0017] Preferably, the drive shaft and the driven shaft are provided with a helical seal ring and a skeleton seal ring. The helical seal ring is located inside the first bearing housing and the second bearing housing and is connected to the end of the sliding bearing. The skeleton seal ring includes a first skeleton seal ring located inside the first bearing, a second skeleton seal ring located inside the second bearing, and a third skeleton seal ring located outside the third bearing. The inner diameter of the first skeleton seal ring is larger than the inner diameter of the first bearing, the inner diameter of the second skeleton seal ring is larger than the inner diameter of the second bearing, and the inner diameter of the third skeleton seal ring is equal to or smaller than the inner diameter of the third bearing.

[0018] The aforementioned sealing structure effectively prevents material leakage from the pump and the entry of external foreign objects into the bearing chamber.

[0019] Preferably, an annular cooling plate is fitted onto the spiral sealing ring, and refrigerant flow channel holes are provided on the annular cooling plate and the housings of the first bearing housing and the second bearing housing.

[0020] The aforementioned annular cooling plate can cool the spiral sealing ring and increase the viscosity of the material to achieve a better sealing effect; the refrigerant flow channels on the first and second bearing housings can be vented with gas or liquid to cool themselves, thereby increasing the service life of the bearings and internal gears.

[0021] Furthermore, the second bearing housing is a closed-cover bearing housing; or the second bearing housing is a through-cover bearing housing in which the drive shaft and driven shaft pass through the pressure plate, and the drive shaft and driven shaft are provided with the refrigerant flow channel holes, and the refrigerant flow channel holes are blind holes arranged along the axial direction.

[0022] This structure further enhances the cooling effect. The aforementioned shaft and pressure plate are connected by bearings and employ a sealed design, with the blind end of the shaft connected to a rotary joint.

[0023] Preferably, the pump body is provided with a heating pipe hole for electric heating or a heat medium flow channel hole for heating the heat medium.

[0024] If the pump body needs to be heated during the transport of the melt to ensure the processing technology and fluidity of the melt, the above structure can be adopted.

[0025] The external meshing high wear-resistant melt gear pump provided by this invention uses an axial adjustment mechanism to fix the ends of the drive shaft and driven shaft, thereby fixing the axial position of the pump gears (i.e., the drive gear and driven gear) integrated with them. This, in turn, fixes the clearance between the end face of the pump gear and the end face of the sliding bearing, preventing wear caused by relative positional changes. Simultaneously, the meshing adjustment mechanism adjusts the meshing fit of the drive helical gear and driven helical gear, keeping the tooth surfaces and grooves of the pump gear pair in a state of just-contact, reducing wear during material transport and improving the pumping accuracy of the gear pump. This invention offers numerous advantages, including compact radial dimensions, a lighter structural design, high operational accuracy, low and stable noise, flexible operating conditions, and strong environmental adaptability. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention.

[0027] Figure 2 yes Figure 1 A schematic diagram of the structure of a locking nut with external threads.

[0028] Figure 3 yes Figure 2 The left view.

[0029] Figure 4 yes Figure 1 Enlarged view of part A in the image.

[0030] Figure 5 yes Figure 1 A schematic diagram of the structure when the drive shaft and driven shaft are equipped with refrigerant flow channel holes. Detailed Implementation

[0031] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific working processes are given. However, the scope of protection of the present invention is not limited to the following embodiments.

[0032] like Figure 1-4 As shown, the external meshing high wear-resistant melt gear pump of the present invention includes a pump body 1, and a driving gear 2, a driven gear 3, and sliding bearings 4 located on both sides of the gears are disposed inside the pump body 1. The driving gear 2 is integrally formed with the driving shaft 5, the driven gear 3 is integrally formed with the driven shaft 6, and the sliding bearings 4 are respectively mounted on the driving shaft 5 and the driven shaft 6.

[0033] One end of the pump body 1 is connected to the first bearing housing 7, and the other end is connected to the second bearing housing 8. In this embodiment, the first bearing housing 7 is a through-cover bearing housing, and the second bearing housing 8 is a closed-cover bearing housing. The second bearing housing 8 and its pressure plate, the pressure plate of the second bearing housing 8 and the pump body 1, the pump body 1 and the second bearing housing 8, and the second bearing housing 8 and its pressure plate are all positioned by pins to ensure assembly accuracy during maintenance or replacement of parts.

[0034] The first bearing housing 7 includes a gear chamber to house the driving helical gear 9 and the driven helical gear 10. The driving helical gear 9 is connected to the driving shaft 5 via a key, and the driven helical gear 10 is connected to the driven shaft 6 via a key. After passing through the first bearing housing 7, the driving shaft 5 is connected to the power output device via a coupling.

[0035] When the drive shaft 5 rotates, the drive helical gear 9 rotates accordingly, and the driven helical gear 10, which meshes with the drive helical gear 9, drives the driven shaft 6 to rotate, so that the material continuously enters from the pump body 1 inlet and is discharged from the pump body 1 outlet.

[0036] The aforementioned driving helical gear 9 and driven helical gear 10 rotate at the same speed but in opposite directions. The driving gear 2, integrally formed with the driving shaft 5, and the driven gear 3, integrally formed with the driven shaft 6, also maintain the same speed and rotate in opposite directions. Since meshing adjustment mechanisms are provided between the driving helical gear 9 and the driving shaft 5, and between the driven helical gear 10 and the driven shaft 6, both located within the first bearing housing 7, and axial adjustment mechanisms are provided on the driving shaft 5 and the driven shaft 6 located within the second bearing housing 8, the center distance between the driving gear 2 and the driven gear 3 remains the same as the center distance between the driving helical gear 9 and the driven helical gear 10 during this process. The end face clearance between the driving gear 2, the driven gear 3, and their respective adjacent sliding bearings 4 remains constant. This reduces tooth surface wear and end face wear of the pump gears (i.e., the driving gear 2 and the driven gear 3), improving pumping accuracy and equipment lifespan.

[0037] Two sets of the aforementioned shaft axial adjustment mechanisms are installed inside the second bearing housing 8, located on the drive shaft 5 and driven shaft 6 respectively. The two sets of shaft axial adjustment mechanisms have the same structure; the following description focuses on the mechanism installed on the drive shaft 5. This shaft axial adjustment mechanism is located outside the first bearing 81 of the second bearing housing 8, and includes an internally threaded locking nut 101 for locking the inner ring of the bearing and an externally threaded locking nut 102 for locking the outer ring of the bearing. The inner ring of the internally threaded locking nut 101 has an internal thread that matches the external thread of the drive shaft 5, and the outer ring of the externally threaded locking nut 102 has an external thread that matches the thread inside the bearing housing. Both have the same main structure, including a radial semi-groove 103 located in the middle of the main body (see...). Figure 2 The radial semi-groove 103 has multiple sets of coaxial paired threaded holes 104 on both sides, and the paired threaded holes 104 can be connected by set screws 105 (see...). Figure 3 When the set screw 105 is tightened, the nut bodies on both sides will move closer to the radial semi-groove 103, changing the pitch of the internal thread locking nut 101 and the external thread locking nut 102. During installation, after adjusting the bearing inner ring to the appropriate position, insert the inner ring spacer 106, then tighten the internal thread locking nut 101 to press against the inner ring spacer 106. Afterward, tighten the set screw 105 so that the pitch of the internal thread locking nut 101 does not match the pitch of the external thread of the drive shaft 5, thus achieving the effect of preventing nut loosening and ensuring a safe and reliable fixation of the bearing inner ring, preventing axial movement. Similarly, after adjusting the bearing outer ring to the appropriate position, insert the outer ring spacer 107, then tighten the external thread locking nut 102 to press against the outer ring spacer 107. Afterward, tighten the set screw 105 so that the pitch of the external thread locking nut 102 does not match the pitch of the internal thread of the bearing housing, achieving a safe and reliable fixation of the bearing outer ring. To achieve a compact structure, the length of the inner ring spacer 106 is greater than the length of the outer ring spacer 107, and the outer diameter of the inner ring spacer 106 is smaller than the inner diameter of the outer ring spacer 107. Under the positioning action of the aforementioned shaft axial adjustment mechanism, the sliding bearing 4 is only used to adjust the clearance with the end faces of the driving gear 2 and driven gear 3 during installation, and does not bear the axial force of the driving gear 2 and driven gear 3 during operation.

[0038] In addition, the aforementioned axial adjustment mechanism can also be located at the other end of the drive shaft 5 and the driven shaft 6, thereby facilitating adjustment of the clearance between the pump gear end face and the sliding bearing 4 end face from both ends. That is, by employing the aforementioned axial adjustment mechanism (see...) Figure 5 The elastic retaining ring 73 (see) replaces the hole on the outside of the second bearing 71 in the first bearing housing 7 in this embodiment. Figure 1 ).

[0039] The aforementioned second bearing 71 is mounted on the housing of the first bearing housing 7. A third bearing 72 is also mounted on the pressure plate of the first bearing housing 7. Between the second bearing 71 and the third bearing 72 is the gear chamber where the driving helical gear 9 and the driven helical gear 10 are located.

[0040] Due to machining errors, the driving helical gear 9 and the driven helical gear 10 may experience gear phase deviation during torque transmission, preventing normal meshing. Therefore, a meshing adjustment mechanism is used to adjust and fix the axial position of the helical gears. One set of this meshing adjustment mechanism is installed on each of the driving shaft 5 and the driven shaft 6. Each set includes a first gear spacer 111 located inside the helical gear, a second gear spacer 112 located inside the helical gear, and an internally threaded locking nut 113 located close to the outside of the second gear spacer 112. The structure of the internally threaded locking nut 113 is the same as that of the internally threaded locking nut 101 in the shaft axial adjustment mechanism. During installation, first adjust the tooth surface and tooth groove clearance of the pump gear pair. Then, select a suitable length of the first gear spacer 111 and install it on the corresponding drive shaft 5 and driven shaft 6 to make the helical gear pair mesh perfectly. After that, install the second gear spacer 112 and the internal thread lock nut 113, and tighten the set screw on the internal thread lock nut 113 so that the pitch of the internal thread lock nut 113 does not match the external thread pitch of the drive shaft 5 / driven shaft 6, thereby achieving the effect of firmly locking the axial position of the drive helical gear 9 and the driven helical gear 10.

[0041] To reduce wear on bearings and gears and extend their service life, oil inlets, drain outlets, vent screw holes, and liquid level observation windows are provided on the first bearing housing 7 and the second bearing housing 8. High-temperature resistant grease or lubricating oil is used to lubricate the gears and bearings.

[0042] High-temperature resistant gaskets are installed between the first bearing housing 7 and its pressure plate, between the second bearing housing 8 and the pump body 1, between the pump body 1 and the second bearing housing 8, and between the second bearing housing 8 and its pressure plate to ensure that the medium does not leak. The drive shaft 5, driven shaft 6 and the first bearing housing 7 and the second bearing housing 8 adopt a structure of "spiral seal ring 12 + annular cooling plate 13". The spiral seal ring 12 is located inside the first bearing housing 7 and the second bearing housing 8 and is connected to the end of the sliding bearing 4, which can play a good role in sealing the melt. Furthermore, the annular cooling plate 13 installed on the outside of the spiral seal 12 cools the material and increases the viscosity of the conveyed material, thereby better utilizing the performance of the spiral seal ring 12. A skeleton seal is also installed at the connection between the drive shaft 5, the driven shaft 6 and the first bearing housing 7 and the second bearing housing 8. This includes a first skeleton seal ring 141 located inside the first bearing 81, a second skeleton seal ring 142 located inside the second bearing 71, and a third skeleton seal ring 143 located outside the third bearing 72. The inner diameter of the first skeleton seal ring 141 is larger than the inner diameter of the first bearing 81, the inner diameter of the second skeleton seal ring 142 is larger than the inner diameter of the second bearing 71, and the inner diameter of the third skeleton seal ring 143 is equal to or smaller than the inner diameter of the third bearing 72. This prevents foreign objects from entering the bearing housing and also prevents lubricating oil or grease in the bearing housing from overflowing to the outside of the equipment and polluting the environment and the equipment.

[0043] The first bearing housing 7 adopts an integrated design of the pump body cover, bearing chamber, and gear chamber. The connection between the pump body cover and the bearing chamber / gear chamber is a hollowed-out transition type with four corners retained, which ensures the machining accuracy of the equipment and facilitates the installation of the spiral seal ring 12 and the annular cooling plate 13. The second bearing housing 8 adopts an integrated design of the pump body cover and bearing chamber. The connection between the pump body cover and the bearing chamber is a hollowed-out transition type with four corners retained. The above design can improve the machining accuracy and facilitate the installation of the spiral seal ring 12 and the annular cooling plate 13.

[0044] Since the melt has the characteristic that its viscosity increases as the temperature decreases until it solidifies, the pump body 1 needs to be heated during the melt transportation process to ensure the fluidity of the melt. Heating is usually done by electric heating or hot coal heating. Therefore, according to the physical properties of the melt and the process requirements, electric heating pipe holes or hot medium flow channel holes for heating medium can be made on the pump body 1.

[0045] Typically, refrigerant flow channels 131 are provided on the annular cooling plate 13 and the housings of the first bearing housing 7 and the second bearing housing 8. Gas or liquid flows through these channels to cool the bearings and internal gears, thereby extending their service life.

[0046] For some special processes, it is necessary to circulate a cooling medium inside the shaft to further enhance the cooling effect, such as... Figure 5As shown, the drive shaft 5 and driven shaft 6 are extended to the outside of the second bearing housing 8 (i.e., the second bearing housing 8 also adopts a through-cover bearing housing), and a refrigerant flow channel hole (i.e., a blind hole) extending from the end towards the pump body 1 is opened at the center of the shaft. The drive shaft 5 and driven shaft 6 are connected by bearings and a sealing design is adopted between the pressure plate of the second bearing housing 8. An adapter is installed at the end of the refrigerant flow channel hole of the drive shaft 5 and driven shaft 6.

[0047] It should be noted that in the description of this invention, terms such as "front," "rear," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

Claims

1. An external meshing high wear-resistant melt gear pump, characterized in that: The pump includes a pump body, which houses a driving gear, a driven gear, and a sliding bearing. The driving gear and the driven gear are integrally formed with the driving shaft, and the sliding bearing is located on both sides of the driving gear and the driven gear. A driving helical gear is mounted on the driving shaft, and a driven helical gear is mounted on the driven shaft. The driving helical gear and the driven helical gear are located in a first bearing housing at one end of the pump body, and a second bearing housing is located at the other end of the pump body. A meshing adjustment mechanism is provided between the driving helical gear and the driving shaft, and between the driven helical gear and the driven shaft, both located in the first bearing housing. An axial adjustment mechanism for the rotating shaft is provided on the driving shaft and the driven shaft, both located in the second bearing housing.

2. The external meshing high wear-resistant melt gear pump according to claim 1, characterized in that: The axial adjustment mechanism of the rotating shaft is located on the outside of the first bearing inside the second bearing housing. It includes an external threaded locking nut and an internal threaded locking nut. The external threaded locking nut is used to fix the outer ring of the bearing, and the internal threaded locking nut is used to fix the inner ring of the bearing. Both the external threaded locking nut and the internal threaded locking nut include a radial semi-groove located in the middle of the main body. Coaxial paired threaded holes are provided on both sides of the radial semi-groove. Set screws for changing the pitch of the external threaded locking nut and the internal threaded locking nut are inserted into the paired threaded holes.

3. The external meshing high wear-resistant melt gear pump according to claim 2, characterized in that: The central angle of the radial half-groove is 180~270°, and the paired threaded holes are evenly distributed in multiple sets along the circumference of the radial half-groove.

4. The external meshing high wear-resistant melt gear pump according to claim 2, characterized in that: An outer ring spacer is provided between the external threaded locking nut and the outer ring of the bearing, and an inner ring spacer is provided between the internal threaded locking nut and the inner ring of the bearing.

5. The external meshing high wear-resistant melt gear pump according to claim 2, characterized in that: The first bearing housing is a through-cover bearing housing, including a second bearing located inside the housing and a third bearing located on the pressure plate. The second bearing is provided with an elastic retaining ring for the hole located inside the bearing housing, or the shaft axial adjustment mechanism is provided inside the bearing housing to replace the elastic retaining ring.

6. The external meshing high wear-resistant melt gear pump according to claim 5, characterized in that: The meshing adjustment mechanism is provided with a first gear spacer located inside the driving helical gear and the driven helical gear, and a second gear spacer located outside the driving helical gear and the driven helical gear. The second gear spacer is provided with an internally threaded locking nut on its outer side.

7. The external meshing high wear-resistant melt gear pump according to claim 5, characterized in that: The drive shaft and driven shaft are provided with a spiral seal ring and a skeleton seal ring. The spiral seal ring is located inside the first bearing housing and the second bearing housing and is connected to the end of the sliding bearing. The skeleton seal ring includes a first skeleton seal ring located inside the first bearing, a second skeleton seal ring located inside the second bearing, and a third skeleton seal ring located outside the third bearing. The inner diameter of the first skeleton seal ring is larger than the inner diameter of the first bearing, the inner diameter of the second skeleton seal ring is larger than the inner diameter of the second bearing, and the inner diameter of the third skeleton seal ring is equal to or smaller than the inner diameter of the third bearing.

8. The external meshing high wear-resistant melt gear pump according to claim 7, characterized in that: An annular cooling plate is fitted onto the spiral sealing ring, and refrigerant flow channel holes are provided on the annular cooling plate and the housings of the first and second bearing housings.

9. The external meshing high wear-resistant melt gear pump according to claim 8, characterized in that: The second bearing housing is a closed-cover bearing housing; or the second bearing housing is a through-cover bearing housing in which the drive shaft and driven shaft pass through the pressure plate, and the drive shaft and driven shaft are provided with the refrigerant flow channel holes, and the refrigerant flow channel holes are blind holes arranged along the axial direction.

10. The external meshing high wear-resistant melt gear pump according to claim 1, characterized in that: The pump body is provided with heating pipe holes for electric heating or heating medium flow channel holes for heating medium.

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