Gear pump with improved sealing performance

Abstract

The gear pump comprises a pump shell, a driving assembly, a motor assembly and a sealing assembly, the pump shell is provided with a containing cavity, a liquid inlet channel, a liquid outlet channel and a shaft hole, the liquid inlet channel, the liquid outlet channel and the shaft hole are communicated with the containing cavity, and the driving assembly is arranged in the containing cavity and used for driving liquid to flow into the containing cavity from the liquid inlet channel and flow out from the liquid outlet channel; the motor assembly comprises an end cover and a motor shaft extending out of the end cover, the motor shaft extends into the containing cavity from the shaft hole and is in transmission connection with the driving assembly, the sealing assembly comprises a sealing piece and an elastic piece, and the sealing piece is annularly arranged on the periphery of the motor shaft, is used for blocking the shaft hole and comprises a sleeve with a sealing cavity and a clamping spring. According to the invention, the snap spring is hooped at the periphery of the sleeve and is connected to the motor assembly to provide radial elastic support for the sealing element, so that radial amplitude generated in the working process of the motor is absorbed, and the purpose of reducing the adverse effect of the radial amplitude on the sealing element is achieved.

Description

[0001] This application is a divisional application of a Chinese invention patent with application number 202311700454.5, application date December 12, 2023, and name “Gear pump with improved sealing performance”. Technical Field

[0002] The invention relates to the technical field of pump body sealing, and in particular to a gear pump with improved sealing performance. Background Art

[0003] When the pump body is working, it mainly realizes the pumping of fluid through the volume change of the inlet and outlet chambers in the chamber. Specifically, the motor shaft can be used to drive the movement of the driving components in the chamber to achieve the purpose of driving the fluid flow. For example, in a gear pump, the motor shaft can drive the gear to rotate, and in a vane pump, the motor shaft can drive the impeller to rotate. The motor shaft usually extends into the chamber through the shaft hole opened on the pump housing.

[0004] In the prior art, a sealing ring can be disposed outside the motor shaft to seal the shaft hole. However, the vibration generated by the motor during operation is inevitably transmitted to the sealing ring, which often causes the sealing ring to loosen and the seal to fail after the pump body is used for a long time, thereby affecting the service life of the pump body.

[0005] To solve the above problem, an elastic part can be arranged in the pump body to form an elastic support for the sealing ring, so that the elastic part can be used to absorb the vibration energy generated during the operation of the motor. However, the prior art only considers the use of elastic parts to absorb the axial amplitude, but does not consider the adverse effects of amplitudes in other directions on the sealing effect. Summary of the invention

[0006] The main purpose of the present invention is to propose a gear pump with improved sealing performance, aiming to solve the problem of easy sealing failure due to vibration of the pump body after long-term use in traditional technology, and to reduce the adverse effects of radial amplitude on the seal.

[0007] To achieve the above object, the present invention provides a gear pump with improved sealing performance, comprising:

[0008] A pump housing having a cavity, wherein the pump housing has a liquid inlet channel, a liquid outlet channel and an axial hole communicating with the cavity;

[0009] A driving assembly, disposed in the chamber, for driving the liquid to flow from the liquid inlet channel into the chamber and out of the liquid outlet channel;

[0010] A motor assembly, comprising an end cover and a motor shaft extending from the end cover, wherein the motor shaft extends from the shaft hole into the cavity and is drivingly connected to the drive assembly; and

[0011] A sealing assembly includes a sealing member and an elastic member. The sealing member is annularly arranged on the outer circumference of the motor shaft and is used to seal the shaft hole. The sealing member includes a sleeve, a first sealing ring and a second sealing ring. The sleeve is sleeved on the outer circumference of the motor shaft. A sealing cavity is defined between the inner circumference of the sleeve and the outer circumference of the motor shaft. The first sealing ring and the second sealing ring are used to jointly seal the sealing cavity. The elastic member also includes a retaining spring. The retaining spring is annularly arranged extending in the circumferential direction and having a notch. The retaining spring is sleeved on the outer circumference of the sleeve and is connected to the motor assembly.

[0012] Optionally, the pump casing has a shell plate facing the end cover, the axial hole is opened on the shell plate, and the motor assembly also includes a wall portion arranged between the shell plate and the end cover, the wall portion is arranged around the outer periphery of the seal and connected to the end cover, the inner periphery of the wall portion is recessed with a mounting groove extending along the circumferential direction, and the outer periphery of the retaining ring is embedded in the mounting groove.

[0013] Optionally, the wall portion is provided with screw holes and / or studs for mounting a gear pump.

[0014] Optionally, the shell plate is fixed to a side of the wall portion facing away from the end cover.

[0015] Optionally, the sleeve has a first end close to the shell plate and a second end close to the end cover, the first sealing ring is arranged between the first end and the shell plate, and the second sealing ring is arranged between the second end and the motor shaft.

[0016] Optionally, the side of the shell plate facing the end cover has a sealing groove arranged in an annular shape on the outer periphery of the axial hole, the first end is provided with an annular step inserted into the sealing groove, the first sealing ring is sleeved on the outer periphery of the annular step and abuts against the bottom wall and side walls of the sealing groove.

[0017] Optionally, the sleeve is open at the second end, and the second sealing ring is disposed in the sealing cavity and clamped between the inner side wall of the sealing cavity and the outer periphery of the motor shaft.

[0018] Optionally, a bearing is provided on the end cover, the motor shaft extends from the bearing, a portion of the bearing is inserted into the opening, and the second sealing ring abuts against the bearing on a side facing away from the sealing cavity.

[0019] Optionally, a gasket is provided on the end side of the bearing facing the shell plate, and the second sealing ring is pressed against the gasket.

[0020] Optionally, the gear pump with improved sealing performance is characterized in that the elastic member includes a compression spring extending in the axial direction, one end of the compression spring elastically abuts against the sleeve, and the other end is connected to the motor assembly.

[0021] In the technical solution provided by the present invention, a seal for blocking the shaft hole is sleeved on the motor shaft of the pump body, and the seal is elastically supported by an elastic member to achieve position limiting. In this way, on the one hand, the elastic member is used to achieve reliable position limiting of the seal, while achieving the purpose of facilitating the disassembly and assembly of the sealing assembly. On the other hand, the elastic member can also absorb the vibration energy generated during the operation of the motor, reduce the adverse effects of the motor vibration on the seal, reduce the situation of the seal ring loosening and the seal failure, thereby extending the service life of the pump body. Specifically, the seal includes a sleeve, and a sealing cavity is defined between the inner periphery of the sleeve and the outer periphery of the motor shaft. The elastic member includes a retaining spring, which is an annular arrangement extending in the circumferential direction and having a notch. The retaining spring is arranged on the outer periphery of the sleeve and connected to the motor assembly to provide radial elastic support for the seal, thereby absorbing the radial amplitude generated during the operation of the motor, and achieving the purpose of reducing the adverse effects of the radial amplitude on the seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 A three-dimensional schematic diagram of an embodiment of a gear pump with improved sealing performance provided by the present invention;

[0024] Figure 2 for Figure 1 Front view of the middle pump body;

[0025] Figure 3 for Figure 2 Cross-sectional view of the pump body;

[0026] Figure 4 for Figure 3 The enlarged schematic diagram of point A in the middle;

[0027] Figure 5 for Figure 1 Schematic diagram of the three-dimensional structure of the pump body;

[0028] Figure 6 for Figure 5 A schematic diagram of the three-dimensional structure of an embodiment of a middle sealing structure;

[0029] Figure 7 for Figure 6 Schematic diagram of the three-dimensional structural decomposition of the sealing structure.

[0030] Description of Figure Numbers:

[0031] 1- pump body; 10- pump casing; 110- cavity; 111- shaft hole; 11- shell plate; 12- sealing groove; 20- driving assembly; 21- driving gear; 22- driven gear; 30- motor assembly; 31- motor shaft; 32- end cover; 33- bearing; 331- gasket; 40- sealing assembly; 41- sealing member; 410- sealing cavity; 411- sleeve; 4111- first end; 4112- second end; 4113- annular step; 4114- bearing surface; 412- first sealing ring; 413- second sealing ring; 42- elastic member; 421- compression spring; 422- retaining spring; 43- limiting column; 431- first limiting groove; 432- second limiting groove; 50- wall; 51- mounting groove.

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] See also Figures 1 to 3 The present invention discloses a pump body 1, specifically, a gear pump with improved sealing performance. Specifically, the pump body 1 includes a pump casing 10, a drive assembly 20, a motor assembly 30 and a sealing assembly 40. The shape and material of the pump casing 10 are not limited, and it has a cavity 110, and the pump casing 10 has a liquid inlet channel, a liquid outlet channel and an axial hole 111 connected to the cavity 110. The drive assembly 20 is arranged in the pump casing 10, and is used to drive the liquid to flow from the liquid inlet channel into the cavity 110 and out of the liquid outlet channel. The specific structure of the drive assembly 20 can be set according to the type of the pump body 1, for example, it can include two gears that mesh with each other or an outer gear ring and an inner gear that mesh with each other.

[0037] In this embodiment, the drive assembly 20 is driven by the motor assembly 30. Specifically, the motor assembly 30 includes an end cover 32 and a motor shaft 31 extending from the end cover 32. The motor shaft 31 extends from the shaft hole 111 into the cavity 110 and is in driving connection with the drive assembly 20 to enable the liquid in the drive assembly 20 to flow and achieve the purpose of pumping liquid. In one embodiment, the drive assembly 20 includes an impeller, and the motor shaft 31 is drivingly connected to the impeller to drive the impeller to rotate.

[0038] In another embodiment, please continue to refer to Figure 3The driving assembly 20 includes a driving gear 21 and a driven gear 22 meshing with each other, the motor shaft 31 is key-connected with the driving gear 21, and the driving gear 21 and the driven gear 22 separate the cavity 110 into a liquid inlet cavity adjacent to the liquid inlet channel, and a liquid outlet cavity adjacent to the liquid outlet channel. When the motor shaft 31 rotates, the driving gear 21 and the driven gear 22 are driven to rotate, the volume of the liquid inlet cavity decreases, and liquid is sucked from the liquid inlet channel, and the volume of the liquid outlet cavity increases, and liquid is discharged to the liquid outlet channel. In this embodiment, the pump body 1 is a gear pump, which has the advantages of simple structure and stable operation.

[0039] For further information, please refer to Figure 3 and Figure 4 The sealing assembly 40 includes a sealing member 41 and an elastic member 42. The sealing member 41 is arranged on the outer periphery of the motor shaft 31. The sealing member 41 may have various structures as long as it can be used to block the shaft hole 111. The elastic member 42 elastically supports the sealing member 41 to limit the position of the sealing member 41. The type of the elastic member 42 is not limited, for example, it may be a compression spring 421, a coil spring or an elastic rubber pad. Preferably, the elastic member 42 has a structure that can stably support the sealing member 41 without hindering the rotation of the motor shaft 31. The elastic member 42 can elastically support the sealing member 41 in the axial direction to absorb the vibration of the motor shaft 31 in the axial direction. The elastic member 42 can also elastically support the sealing member 41 in the radial direction to absorb the vibration of the motor shaft 31 in the radial direction. In this embodiment, on the one hand, the elastic member 42 is used to achieve reliable positioning of the seal 41, while achieving the purpose of facilitating disassembly and assembly of the seal assembly 40; on the other hand, the elastic member 42 can also absorb the vibration energy generated during the operation of the motor, thereby reducing the adverse effects of the motor vibration on the seal 41, reducing the loosening of the sealing ring and the failure of the seal, thereby extending the service life of the pump body 1.

[0040] Specifically, in one embodiment, please refer to Figures 4 to 7 , the pump housing 10 has a shell plate 11 facing the end cover 32, and the axial hole 111 is provided on the shell plate 11. The shell plate 11 can be integrally formed on the pump body 1, or assembled on the pump housing 10, as long as the sealing of the cavity 110 can be maintained. The integrally formed arrangement of the pump housing 10 can make the cavity 110 have good sealing performance, and the assembly of the pump housing 10 to the cavity 110 can facilitate the installation of the drive assembly 20 inside the cavity 110. In this embodiment, the shell plate 11 is a part of the pump housing 10, and is provided with an axial hole 111. The end cover 32 of the motor assembly 30 is spaced apart from the shell plate 11 in the axial direction, and the motor shaft 31 thereof extends from the end cover 32, passes through the sealing assembly 40, and then passes through the axial hole 111, and extends into the cavity 110.

[0041] The elastic member 42 includes a compression spring 421 extending in the axial direction, one end of the compression spring 421 elastically abuts against the seal 41, and the other end is connected to the motor assembly 30. In this way, the compression spring 421 elastically presses the seal 41 against the shaft hole 111 in the direction extending from the end cover 32 to the shell plate 11 to achieve a sealing effect. In this embodiment, when installing the pump body 1, the compression spring 421 and the seal 41 can be sleeved one by one on the outer periphery of the motor shaft 31, and then the pump housing 10 is installed, which is easy to operate. After installation, the elastic pressure of the compression spring 421 reliably presses the seal 41 against the shaft hole 111 to achieve sealing of the shaft hole 111. When the pump body 1 is working, the compression spring 421 can well absorb the vibration of the motor assembly 30 in the axial direction, reduce the shaking effect of the vibration of the motor assembly 30 on the seal 41, reduce the probability of the seal 41 loosening due to vibration, improve the sealing performance of the sealing assembly 40, and extend the service life of the pump body 1.

[0042] On the basis of the previous embodiment, the seal 41 can be directly set as a sealing ring, which is accommodated in the shaft hole 111 and directly abuts against the compression spring 421. In this way, the sealing ring is movable in the axial direction, although the structure is simple, once it is loosened from the shaft hole 111, it will cause leakage.

[0043] To this end, in a preferred embodiment, the sealing member 41 includes a sleeve 411, a first sealing ring 412 and a second sealing ring 413. The sleeve 411 is sleeved on the outer periphery of the motor shaft 31 and has a first end 4111 close to the shell plate 11 and a second end 4112 close to the end cover 32. A sealed cavity 410 is defined between the inner periphery of the sleeve 411 and the outer periphery of the motor shaft 31. The sealed cavity 410 is connected to the accommodating cavity 110. The first sealing ring 412 is arranged between the first end 4111 and the shell plate 11. The second sealing ring 413 is arranged between the second end 4112 and the motor shaft 31. The first sealing ring 412 and the second sealing ring 413 are used to jointly seal the sealed cavity 410. In this embodiment, the sleeve 411 is in direct contact with the compression spring 421, and a sealing cavity 410 communicating with the accommodating cavity 110 is formed therein, and the first sealing ring 412 and the second sealing ring 413 are respectively arranged at both ends of the sleeve 411 in the axial direction, so as to seal the sealing cavity 410 from both ends, thereby achieving a good sealing effect. Such an arrangement can prevent the compression spring 421 from directly contacting the sealing ring, which may cause the sealing ring to be easily displaced and deformed in the axial direction, resulting in sealing failure.

[0044] Based on the previous embodiment, please refer to Figures 4 to 7The shell plate 11 has a sealing groove 12 arranged on the outer periphery of the shaft hole 111 on one side facing the end cover 32. The first end 4111 is provided with an annular step 4113 inserted into the sealing groove 12. The first sealing ring 412 is sleeved on the outer periphery of the annular step 4113 and abuts against the bottom wall and side wall of the sealing groove 12. In this way, the first sealing ring 412 is limited by the sleeve 411 in the axial direction and is not easy to move or deform in the axial direction. In addition, the first sealing ring 412 has a sealing effect on the inner and outer peripheries, as well as the upper and lower sides in the radial direction. The sealing contact surface is larger and the sealing effect is better. When the hydraulic pressure in the sealing chamber 410 increases, the first sealing ring 412 is pressed more tightly against the shell plate 11, which enhances the sealing effect and improves the sealing performance of the sealing assembly 40.

[0045] In one embodiment, please continue to refer to Figure 4 , the sleeve 411 is open at the second end 4112, and the second sealing ring 413 is arranged in the sealing cavity 410, and is clamped between the inner wall of the sealing cavity 410 and the outer periphery of the motor shaft 31. In this embodiment, the sleeve 411 plays a role in tightening the second sealing ring 413, thereby enhancing the sealing performance of the second sealing ring 413. Preferably, the material of the sleeve 411 is rubber, silicone or other materials with a certain elasticity, so that it plays a role in increasing the friction resistance to the second sealing ring 413 and reducing the rotation of the second sealing ring 413 with the motor shaft 31. Preferably, the material of the sleeve 411 can be a material with good thermal conductivity such as graphite or metal, so as to reduce the friction temperature rise of the second sealing ring 413 when the motor shaft 31 rotates, thereby improving the service life of the second sealing ring 413.

[0046] For further information, please refer to Figures 4 to 7 The end cover 32 is provided with a bearing 33, the motor shaft 31 extends from the bearing 33, the bearing 33 is partially inserted in the opening, and the second sealing ring 413 abuts against the bearing 33 on the side facing away from the sealing cavity 410. In this embodiment, the second sealing ring 413 is supported in the axial direction by the end side of the bearing 33 facing the shell plate 11, which plays a role in limiting the axial position of the second sealing ring 413, and when the hydraulic pressure in the sealing cavity 410 increases, the second sealing ring 413 can be pressed more tightly against the bearing 33, and the sealing performance of the second sealing ring 413 is further enhanced by the hydraulic pressure.

[0047] Optionally, a gasket 331 is provided on the end side of the bearing 33 facing the shell plate 11, and the second sealing ring 413 presses against the gasket 331. In this way, the gasket 331, on the one hand, makes the contact surface between the bearing 33 and the second sealing ring 413 smooth, thereby avoiding the wear of the second sealing ring 413, and on the other hand, also plays a heat conduction role, thereby reducing the friction temperature rise caused by the relative rotation of the second sealing ring 413 and the motor shaft 31, thereby extending the service life of the second sealing ring 413.

[0048] Based on the above examples, please continue to refer to Figures 4 to 7 , a first limiting groove 431 is provided on the outer circumference of the bearing 33, and a second limiting groove 432 is provided on the circumference of the sleeve 411, the first limiting groove 431 and the second limiting groove 432 extend in the axial direction respectively, and the sealing assembly 40 further comprises a limiting column 43 inserted in the first limiting groove 431 and the second limiting groove 432. In this embodiment, the limiting column 43 cooperates with the first limiting groove 431 and the second limiting groove 432 to limit the sleeve 411 in the circumferential direction, so as to prevent the sleeve 411 from rotating relative to the bearing 33 in the circumferential direction, so as to improve the sealing performance of the sealing element 41. At the same time, the first limiting groove 431 and the second limiting groove 432 are both long in shape with the length direction extending in the axial direction, so that the elastic supporting function of the compression spring 421 in the axial direction is not affected.

[0049] On the basis of the above embodiment, the outer circumference of the sleeve 411 is provided with a bearing surface 4114 facing the end cover 32, one end of the compression spring 421 abuts against the bearing surface 4114, and the other end abuts against the motor assembly 30. In this way, the sleeve 411 plays a guiding role, so that the compression spring 421 is compressed in the axial direction.

[0050] Furthermore, a bearing 33 is provided on the end cover 32, and the bearing 33 has an open groove (not shown in the figure) facing the shell plate 11, and the open groove is arranged around the outer periphery of the motor shaft 31. One end of the compression spring 421 abuts against the motor assembly 30 and is inserted into the open groove and abuts against the bottom of the open groove. In this way, the compression spring 421 is further guided by the open groove to prevent the compression spring 421 from deflecting.

[0051] Optionally, the motor shaft 31 is also sleeved with a third sealing ring (not shown in the figure), and the third sealing ring is sandwiched between the inner periphery of the shaft hole 111 and the outer periphery of the motor shaft 31. In this way, the shaft hole 111 is double-sealed, and when the third sealing ring fails to seal, the first sealing ring 412 and the second sealing ring 413 continue to seal, thereby enhancing the sealing performance of the pump body 1 and prolonging the service life of the pump body 1.

[0052] Please continue reading Figure 4 and Figure 5The elastic member 42 further includes a retaining spring 422, which is arranged in a ring shape extending in the circumferential direction and having a notch. The retaining spring 422 is sleeved on the outer circumference of the sleeve 411 and connected to the motor assembly 30. In this embodiment, the elastic member 42 further includes a retaining spring 422, which elastically supports the seal 41 in the radial direction to absorb the vibration of the motor in the radial direction, further improve the vibration resistance of the seal 41, and reduce the probability of sealing failure caused by loosening due to vibration.

[0053] Based on the above embodiment, the motor assembly 30 further includes a wall portion 50 disposed between the shell plate 11 and the end cover 32. The wall portion 50 is disposed around the outer periphery of the seal 41 and connected to the end cover 32. The inner periphery of the wall portion 50 is recessed with a mounting groove 51 extending in the circumferential direction, and the outer periphery of the retaining spring 422 is embedded in the mounting groove 51. In this embodiment, the retaining spring 422 is fixedly supported in the radial direction by the annular mounting groove 51 provided on the wall portion 50, so as to firmly support the sleeve 411. Figure 5 As shown, the shell plate 11 is fixed to the side of the wall portion 50 facing away from the end cover. Preferably, the wall portion 50 may also be provided with screw holes and / or studs for mounting the pump body 1.

[0054] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A gear pump with improved sealing performance, characterized in that: include: A pump housing having a cavity, wherein the pump housing has a liquid inlet channel, a liquid outlet channel and an axial hole communicating with the cavity; A driving assembly, disposed in the chamber, for driving the liquid to flow from the liquid inlet channel into the chamber and out of the liquid outlet channel; A motor assembly, comprising an end cover and a motor shaft extending from the end cover, wherein the motor shaft extends from the shaft hole into the cavity and is drivingly connected to the drive assembly; and A sealing assembly includes a sealing member and an elastic member. The sealing member is annularly arranged on the outer circumference of the motor shaft and is used to seal the shaft hole. The sealing member includes a sleeve, a first sealing ring and a second sealing ring. The sleeve is sleeved on the outer circumference of the motor shaft. A sealing cavity is defined between the inner circumference of the sleeve and the outer circumference of the motor shaft. The first sealing ring and the second sealing ring are used to jointly seal the sealing cavity. The elastic member also includes a retaining spring. The retaining spring is annularly arranged extending in the circumferential direction and having a notch. The retaining spring is sleeved on the outer circumference of the sleeve and is connected to the motor assembly.

2. The gear pump with improved sealing performance as claimed in claim 1, characterized in that: The pump casing has a shell plate facing the end cover, the axial hole is opened on the shell plate, the motor assembly also includes a wall portion arranged between the shell plate and the end cover, the wall portion is arranged around the outer periphery of the seal and connected to the end cover, the inner periphery of the wall portion is recessed with a mounting groove extending in the circumferential direction, and the outer periphery of the retaining ring is embedded in the mounting groove.

3. The gear pump with improved sealing performance as claimed in claim 2, characterized in that: The wall portion is provided with screw holes and / or studs for mounting the gear pump.

4. The gear pump with improved sealing performance as claimed in claim 2, characterized in that: The shell plate is fixed to a side of the wall portion facing away from the end cover.

5. The gear pump with improved sealing performance as claimed in claim 4, characterized in that: The sleeve has a first end close to the shell plate and a second end close to the end cover, the first sealing ring is arranged between the first end and the shell plate, and the second sealing ring is arranged between the second end and the motor shaft.

6. The gear pump with improved sealing performance as claimed in claim 5, characterized in that: The shell plate has a sealing groove arranged on the outer periphery of the axial hole on one side facing the end cover, the first end is provided with an annular step inserted into the sealing groove, the first sealing ring is sleeved on the outer periphery of the annular step and abuts against the bottom wall and side walls of the sealing groove.

7. The gear pump with improved sealing performance as claimed in claim 5, characterized in that: The sleeve is open at the second end, and the second sealing ring is arranged in the sealing cavity and sandwiched between the inner side wall of the sealing cavity and the outer periphery of the motor shaft.

8. The gear pump with improved sealing performance as claimed in claim 7, characterized in that: A bearing is arranged on the end cover, the motor shaft extends from the bearing, a part of the bearing is inserted into the opening, and the second sealing ring abuts against the bearing on a side facing away from the sealing cavity.

9. The gear pump with improved sealing performance as claimed in claim 8, characterized in that: A gasket is arranged on the end side of the bearing facing the shell plate, and the second sealing ring is pressed against the gasket.

10. The gear pump with improved sealing performance according to any one of claims 4 to 9, characterized in that: The gear pump with improved sealing performance is characterized in that the elastic member includes a compression spring extending in the axial direction, one end of the compression spring elastically abuts against the sleeve, and the other end is connected to the motor assembly.

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