Pump assembly

Abstract

The application relates to a pump assembly. The pump assembly comprises a housing, a motor, a transmission shaft and a sealing structure. The housing comprises a liquid cavity, a connecting cavity, a liquid outlet and a communication hole; the liquid outlet is arranged on the side of the liquid cavity away from the connecting cavity; the communication hole communicates the liquid cavity and the connecting cavity. The motor is connected to the housing on one side of the connecting cavity; the motor comprises a driving shaft; the driving shaft extends into the connecting cavity. The transmission shaft is arranged in the liquid cavity and extends into the connecting cavity and is connected to the driving shaft in the axial direction; the driving shaft is used for driving the transmission shaft to rotate; the transmission shaft is used for driving the liquid in the liquid cavity to leave through the liquid outlet by rotation. At least part of the sealing structure is sleeved on the outer periphery of the transmission shaft and arranged in the communication hole, and is used for preventing the liquid in the liquid cavity from entering the connecting cavity through the communication hole; the sealing structure comprises a dynamic sealing part and a static sealing part.

Description

Technical Field

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

[0002] In chemical production processes, screw pumps have become key equipment for conveying corrosive liquids (such as acid and alkali solutions, organic solvents, and chloride-containing media) due to their stable delivery, adaptability to high-viscosity media, and low shear characteristics.

[0003] Because leaks of corrosive liquids can damage components of pump assemblies with weak corrosion resistance, such as the motor, and may also cause personal injury to personnel near the pump assembly, these pump assemblies have higher requirements for fluid sealing performance. Utility Model Content

[0004] This application provides a pump assembly to address some or all of the shortcomings of the related art.

[0005] The pump assembly of this application includes:

[0006] The housing includes a communicating liquid cavity, a connecting cavity, a liquid outlet, and a communicating hole; the liquid outlet is located on the side of the liquid cavity away from the connecting cavity; the communicating hole connects the liquid cavity and the connecting cavity.

[0007] A motor is connected to the housing on one side of the connecting cavity; the motor includes a drive shaft; the drive shaft extends into the connecting cavity;

[0008] A transfer shaft, disposed in the liquid chamber and extending into the connecting cavity, is axially connected to the drive shaft; the drive shaft is used to drive the transfer shaft to rotate; the transfer shaft is used to drive the liquid in the liquid chamber to leave through the outlet by rotation; and,

[0009] A sealing structure; at least a portion of the sealing structure is sleeved on the outer periphery of the transmission shaft and disposed in the communicating hole to prevent fluid in the liquid cavity from entering the connecting cavity through the communicating hole; the sealing structure includes a dynamic sealing part and a static sealing part.

[0010] Furthermore, the dynamic sealing part includes:

[0011] A stationary ring is fitted onto the transmission shaft; the stationary ring is connected to the inner wall of the housing;

[0012] A moving ring is fitted onto the transmission shaft; the moving ring abuts against the end face of the stationary ring facing the liquid outlet; the moving ring is connected to the transmission shaft and rotates with the transmission shaft.

[0013] Furthermore, the static sealing part includes a first sealing ring; the first sealing ring is sleeved on the outer periphery of the static ring; the first sealing ring is interference-fitted with the inner wall of the housing.

[0014] Furthermore, the sealing structure includes a limiting portion; the limiting portion includes:

[0015] A rubber ring includes a first end facing the liquid outlet and a second end facing the connecting hole; the rubber ring is sleeved on the transmission shaft; the first end is interference-fitted with the transmission shaft; the rubber ring includes a limiting hole disposed at the second end; a moving ring is disposed in the limiting hole and is interference-fitted with the limiting hole; there is a gap between the moving ring and the surface of the transmission shaft.

[0016] Furthermore, the limiting part also includes:

[0017] A limiting member is adsorbed and connected to the first end of the rubber ring; the transmission shaft includes a keyway; the limiting member includes a protrusion that mates with the keyway; the protrusion mates with the keyway to allow the transmission shaft to drive the limiting member to rotate; the limiting member is used to restrict the position of the rubber ring and the dynamic seal in the axial direction, and to apply a force to the rubber ring from the liquid outlet in the direction of the connecting hole.

[0018] Furthermore, the rubber ring includes a deformable segment disposed between the first end and the second end; the size of the deformable segment in the axial direction is changeable to change the distance between the first end and the second end in the axial direction; at least a portion of the deformable segment has a gap with the wall surface of the transmission shaft.

[0019] Furthermore, the sealing structure also includes:

[0020] A limiting ring includes an abutting end face and multiple mating protrusions; the mating protrusions are disposed on the side of the limiting ring away from the abutting end face; a mating groove of the limiting ring is formed between adjacent mating protrusions; the limiting ring is interference-fitted with the rubber ring on the side of the rubber ring away from the transmission shaft; the limiting ring includes two rings, namely a first ring and a second ring;

[0021] The abutting end face of the first ring is disposed facing the first end; the end face of the second ring is disposed facing the second end; the mating protrusion of the first ring is inserted into the mating groove of the second ring; when the deformed segment is not deformed, there is a gap between the first ring and the second ring in the axial direction.

[0022] Furthermore, the limiting ring is a polyetheretherketone limiting ring.

[0023] Furthermore, the moving ring is a silicon carbide moving ring; the stationary ring is a silicon carbide stationary ring.

[0024] Furthermore, the housing includes a liquid housing portion and a connecting housing portion; the liquid cavity is disposed in the liquid housing portion; the connecting cavity is disposed in the connecting housing portion; the liquid outlet is disposed on the side of the liquid housing portion away from the connecting housing portion; a portion of the communicating hole is disposed in the liquid housing portion and another portion is disposed in the connecting housing portion;

[0025] The communicating hole includes a sealing unit and an abutment unit disposed on the liquid shell portion; the abutment unit is disposed between the sealing unit and the connecting cavity; the diameter of the sealing unit is larger than the diameter of the liquid cavity and smaller than the diameter of the abutment unit; wherein,

[0026] The housing further includes a plenum portion; one end of the plenum portion includes a flange; the flange abuts against the abutting unit; the end of the plenum portion away from the flange extends into the connecting cavity; the transmission shaft passes through the plenum portion; the dynamic sealing portion is disposed on the side of the plenum portion facing the transmission shaft; the static sealing portion is disposed on the sealing unit.

[0027] Furthermore, the end face of the plenum facing the liquid cavity includes a sealing protrusion; the sealing protrusion cooperates with the sealing unit to form a sealed cavity with an opening communicating with the liquid cavity;

[0028] The static sealing part includes a second sealing ring; the second sealing ring is disposed in the sealing cavity and is interference-fitted with the wall surface of the sealing unit; the dimension of the second sealing ring in the axial direction is smaller than the dimension of the sealing cavity in the axial direction.

[0029] Furthermore, the plenum portion is a polytetrafluoroethylene plenum portion.

[0030] Further, the housing includes a liquid shell portion and a connecting shell portion; the liquid cavity is disposed in the liquid shell portion; the connecting cavity is disposed in the connecting shell portion; the liquid outlet is disposed on the side of the liquid shell portion away from the connecting shell portion; a portion of the communicating hole is disposed in the liquid shell portion and another portion is disposed in the connecting shell portion; wherein,

[0031] The connecting cavity is connected to the outside at both ends in a direction perpendicular to the axial direction.

[0032] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0033] As can be seen from the above embodiments, the dynamic seal of the pump assembly of this application achieves sealing by forming an extremely thin liquid film as it rotates with the transmission shaft. This prevents fluid in the liquid chamber from leaking along the transmission shaft into the connecting chamber, while also preventing external air or other media from entering the liquid chamber through the connecting hole. The static seal prevents fluid leakage through the stationary connecting surface, ensuring that the fluid can only flow within the designed flow path. The combination of the dynamic and static seals can achieve fluid sealing of the liquid chamber through various sealing methods, thereby improving the sealing performance of the pump assembly against corrosive fluids, and thus improving the service life and safety of the pump assembly.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 The diagram shows an overall schematic representation of an embodiment of the pump assembly of this application;

[0037] Figure 2 Shown as Figure 1 A schematic cross-sectional view of the pump assembly shown;

[0038] Figure 3 Shown as Figure 2 The enlarged view of part A shown;

[0039] Figure 4 The diagram shown is a partially enlarged schematic of an embodiment of the pump assembly of this application, with the liquid housing, transmission shaft, and part of the motor hidden.

[0040] Figure 5 The diagram shown is a partially enlarged schematic of one embodiment of the housing of this application;

[0041] Figure 6 The diagram shows an overall schematic representation of one embodiment of the transmission shaft of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100 Pump assembly, 1 Housing, 11 Liquid housing section, 111 Liquid chamber, 1111 Liquid outlet, 1112 Connecting hole, 1112a Sealing unit, 1112b Abutment unit, 112 Transition section, 1121 Receiving protrusion, 113 Suction section, 1131 Liquid inlet, 1132 Receiving groove, 114 Stator section, 1141 Stator housing unit, 1142 Rubber stator, 115 Discharge section, 116 Receiving cavity, 117 Sealing cavity, 12 Connecting housing section, 121 Connecting cavity, 13 Gland section, 131 Flange, 132 Sealing protrusion, 2 Motor, 21 Drive shaft, 211 Second insertion hole, 3 Transmission shaft, 31 Transmission section, 31 1. Drive hole, 312. First insertion hole, 313. Boss, 32. Connecting section, 33. Screw section, 34. Keyway, 4. Sealing structure, 41. Dynamic sealing part, 411. Stationary ring, 412. Dynamic ring, 42. Stationary sealing part, 421. First sealing ring, 422. Second sealing ring, 423. Third sealing ring, 43. Limiting part, 431. Rubber ring, 4311. First end, 4312. Second end, 4313. Limiting hole, 4314. Deformation section, 432. Limiting piece, 4321. Protrusion, 44. Limiting ring, 441. Abutting end face, 442. Mating protrusion, 443. Mating groove, 44a. First ring, 44b. Second ring, 5. Pin, 6. Sheath, Z-axis direction. Detailed Implementation

[0044] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0045] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0046] refer to Figures 1 to 6This application provides a pump assembly 100. The pump assembly 100 includes a housing 1, a motor 2, and a transmission shaft 3. The housing 1 includes a liquid shell portion 11. The liquid shell portion 11 includes a liquid cavity 111 extending in the axial direction Z. The liquid cavity 111 includes an outlet 1111 and a connecting hole 1112 disposed opposite to each other. The motor 2 is connected to the housing 1 on the side of the housing 1 away from the outlet 1111. The motor 2 includes a drive shaft 21 extending in the axial direction Z. The transmission shaft 3 is disposed in the liquid cavity 111 and connected to the drive shaft 21 at one end of the connecting hole 1112. The drive shaft 21 is used to drive the transmission shaft 3 to rotate. The transmission shaft 3 is used to drive the liquid in the liquid cavity 111 to leave through the outlet 1111 by rotation. The liquid shell portion 11 is made of a non-metallic material. The transmission shaft 3 housed in the liquid cavity 111 is also made of a non-metallic material.

[0047] The liquid chamber 111 within the liquid housing 11 is used to contain the liquid. When the pump assembly 100 is used in applications such as chemical, environmental, or oilfield environments where the liquid is corrosive, the non-metallic liquid housing 11 provides corrosion resistance more economically than metallic materials, thus preventing damage to the pump assembly 100 due to liquid corrosion after long-term use. Simultaneously, the transmission shaft 3 housed within the liquid chamber 111 is also made of a non-metallic material, thus ensuring corrosion resistance in the power transmission components of the pump assembly 100.

[0048] The pump assembly 100 of this application has non-metallic liquid-contact components, which have good corrosion resistance, enabling the pump assembly 100 to pump corrosive liquids. Furthermore, compared to metallic materials, the liquid housing 11 and transmission shaft 3 of the pump assembly 100 of this application can effectively reduce the weight and processing cost of the pump assembly 100.

[0049] Figure 1 and Figure 2 The structure of motor 2 shown is intended as exemplary and not limiting. This application does not limit the specific dimensions, shape, or drive parameters of motor 2. Those skilled in the art can select appropriate motor 2 parameters based on the properties of the fluid pumped by pump assembly 100. Furthermore, as... Figure 3 As shown, the connecting hole 1112 connects the liquid cavity 111 and the connecting cavity 121. The connecting cavity 121 is defined by the connecting shell portion 12, and the liquid cavity 111 is defined by the liquid shell portion 11. Therefore, it is easy to understand that part of the connecting hole 1112 is located in the connecting shell portion 12, and the other part of the connecting hole 1112 is located in the liquid shell portion 11.

[0050] Optionally, the housing 1 includes a connecting housing portion 12. One side of the connecting housing portion 12 is connected to the liquid housing portion 11, and the other side is connected to the motor 2. The connecting housing portion 12 includes a connecting cavity 121. One end of the transmission shaft 3 away from the liquid outlet 1111 extends into the connecting cavity 121 and is connected to the drive shaft 21 in the axial direction Z in the connecting cavity 121. Further, the connecting housing portion 12 is made of metal. Since the connecting housing portion 12 is used to connect the liquid housing portion 11 and the motor 2, and the connecting cavity 121 is not used to contain fluid, the corrosion resistance requirements of the connecting housing portion 12 in the pump assembly 100 are reduced, while the connection strength requirements are increased. By making the liquid housing portion 11 non-metallic and the connecting housing portion 12 metallic, the pump assembly 100 of this application can effectively prevent corrosive fluid from penetrating the liquid housing portion 11 and can also effectively ensure the stability of the connection between the connecting housing portion 12 and the liquid housing portion 11.

[0051] Optionally, such as Figure 1 and Figure 2 As shown, the connecting cavity 121 is connected to the outside at both ends in the direction perpendicular to the axial direction Z. Figure 2 In the illustrated embodiment, the connecting cavity 121 communicates with the outside at both ends of the pump assembly 100. In other embodiments, the connecting cavity 121 may also communicate with the outside at both the upper and lower ends of the pump assembly 100. This arrangement not only effectively reduces the weight of the connecting housing 12 but also improves the structural strength of the connecting housing 12, which is beneficial for improving the strength of the connecting housing 12 in supporting the liquid housing 11 in the axial direction Z. In addition, the connecting cavity 121 communicating with the outside can also assist assembly personnel in operating the connection between the drive shaft 21 and the motor 2 shaft through the connecting cavity 121, facilitating assembly.

[0052] Combination Figure 2 and Figure 5In some optional embodiments, the liquid housing 11 includes a transition section 112 and a suction section 113. The transition section 112 is connected to the side of the suction section 113 away from the outlet 1111. The suction section 113 includes an inlet 1131. The inlet 1131 communicates with the liquid chamber 111 and is used to introduce fluid into the liquid chamber 111. The suction section 113 and the transition section 112 are made of different materials. Because the suction section 113 has the inlet 1131, it needs to be connected to pipes or other components to introduce external fluid into the liquid chamber 111 for pumping. Since the suction section 113 needs to be connected to other components and also needs to withstand the force of fluid entering the liquid chamber 111, the different materials of the suction section 113 and the transition section 112 effectively reduce the overall cost of the pump assembly 100. For example, the suction section 113 can be made of a material with higher mechanical strength, while the transition section 112, since it does not need to withstand the impact of fluid inflow, can be made of a material with lower mechanical strength than the suction section 113. In addition, the arrangement of the transition section 112 can increase the overall volume of the liquid chamber 111, thereby improving the pumping efficiency of the pump assembly 100.

[0053] In some optional embodiments, the suction section 113 is made of polyvinylidene fluoride (PVDF). PVDF has excellent creep resistance and compressive strength, as well as strong corrosion resistance. Therefore, when corrosive fluid enters the liquid chamber 111 through the inlet 1131 and generates fluid pressure and vibration, the PVDF suction section 113 can also reduce the risk of deformation, thereby improving the service life of the pump assembly 100. In some optional embodiments, the transition section 112 is made of polytetrafluoroethylene (PTFE). PTFE has better corrosion resistance, enabling the pump assembly 100 to pump highly corrosive fluids. In addition, the transition section 112 is located closer to the motor 2 than the suction section 113, so the heat generated by the motor 2 reaches the transition section 112 before the suction section 113. PTFE also has good high-temperature resistance, which can prevent the heat generated by the motor 2 from negatively affecting the liquid housing 11, thereby improving the service life of the liquid housing 11.

[0054] refer to Figure 2 In some alternative embodiments, the liquid housing 11 includes a stator section 114. The stator section 114 is connected to the side of the suction section 113 facing the liquid outlet 1111. The stator section 114 includes a stator housing unit 1141 and a rubber stator 1142 disposed within the stator housing unit 1141. Figure 6The transmission shaft 3 of this application includes a transmission section 31, a connecting section 32, and a screw section 33. The transmission section 31 is used to connect to the drive shaft 21 of the motor 2. The connecting section 32 connects the transmission section 31 and the transition section 112. The screw section 33 cooperates with the rubber stator 1142 to discharge the fluid in the liquid chamber 111 through the outlet 1111 when the transmission shaft 3 rotates. The rubber stator 1142 has corrosion resistance, which can prevent the corrosive fluid in the liquid chamber 111 from corroding the stator. At the same time, the stator housing unit 1141 does not directly contact the corrosive fluid with the cooperation of the rubber stator 1142, so it can be made of metal to improve the structural strength of the liquid housing part 11.

[0055] Admittedly, the stator housing unit 1141 can also be made of a non-metallic material, thereby providing the liquid housing 11 with more comprehensive corrosion resistance. This application does not limit this. The rubber stator 1142 can be made of fluororubber, hydrogenated nitrile rubber, ethylene propylene rubber, etc. These materials have certain corrosion resistance properties.

[0056] In the embodiments of this application, the connecting section 32 and the screw section 33 of the transmission shaft 3 are both located in the liquid cavity 111. Therefore, the transmission shaft 3 is made of non-metallic material at least at the connecting section 32 and the screw section 33, thereby effectively preventing corrosive fluids from corroding the transmission shaft 3. Optionally, the transmission shaft 3 is integrally formed, that is, the connecting section 32, the screw section 33, and the transmission section 31 are all made of the same material. This arrangement is beneficial to improving the structural strength and overall corrosion resistance of the transmission shaft 3, and also helps to reduce the number of rotors, insertion shafts, and other components required to connect the three sections of the transmission shaft 3.

[0057] Furthermore, the materials used for the transfer shaft 3 include polyetheretherketone (PEEK), graphite, carbon fiber, and polytetrafluoroethylene (PTFE). PTFE is resistant to strong acids, strong alkalis, and organic solvents, giving the transfer shaft 3 better chemical inertness and preventing corrosion. PEEK also exhibits high stability against common corrosive media such as hydrochloric acid and sulfuric acid, and its combination with PTFE further enhances the corrosion resistance of the transfer shaft 3. Carbon fiber is microscopically uniformly distributed within the transfer shaft 3, thereby preventing corrosive fluids from penetrating into its interior and thus delaying corrosion. Graphite exhibits strong stability in non-oxidizing environments, enhancing overall acid and alkali resistance. Therefore, the transfer shaft 3 formed by the above material combination possesses more stable chemical inertness, thereby increasing its service life when immersed in corrosive fluids.

[0058] Optionally, the content of polyetheretherketone (PEEK) is greater than or equal to 60% and less than or equal to 80%. The content of graphite is greater than or equal to 8% and less than or equal to 12%. The content of carbon fiber is greater than or equal to 8% and less than or equal to 12%. The content of polytetrafluoroethylene (PTFE) is greater than or equal to 8% and less than or equal to 12%. In other words, the main matrix material of the transmission shaft 3 is PEEK. The high proportion of PEEK gives the transmission shaft 3 a higher strength structure and better heat resistance. Graphite, carbon fiber, and PTFE can provide rigidity enhancement and improved toughness, enabling the transmission shaft 3 to have better transmission characteristics and a longer service life.

[0059] It should be noted that the content range of the material in the transmission shaft 3 can fully meet the above-mentioned content ratio. Alternatively, the transmission shaft 3 can also have only one, two, or three materials that meet the above-mentioned ratio range.

[0060] Returning to the description of the liquid housing 11, in some optional embodiments, the liquid housing 11 further includes a discharge section 115. The discharge section 115 is located on the side of the stator section 114 away from the suction section 113. A liquid outlet 1111 is located in the discharge section 115. The discharge section 115 is made of polyvinylidene fluoride (PVDF). As mentioned above, PVDF has excellent creep resistance and compressive strength, as well as strong corrosion resistance, giving the discharge section 115 good corrosion resistance and deformation resistance. Alternatively, the discharge section 115 may be made of the same material as the suction section 113. The suction section 113 has a liquid inlet, which causes a pressure change when fluid enters the liquid chamber 111 from the inlet. The fluid exits the liquid chamber 111 at the liquid outlet 1111 of the discharge section 115, thus a pressure change also exists in the discharge section 115. Therefore, setting the material of the discharge section 115 and the suction section 113 to be the same can reduce the requirements of the liquid shell 11 on the type of material, thereby controlling production costs.

[0061] Since the liquid shell 11 comprises multiple regions along the axial direction Z, the length of the transmission shaft 3 along the axial direction Z should also be correspondingly set. The screw section 33 of the transmission shaft 3 is used to drive the fluid out of the liquid chamber 111. The transmission section 31 is connected to the drive shaft 21. Therefore, the connecting section 32 actually only serves to connect the transmission section 31 and the screw section 33. In some optional embodiments, the outer diameter of the connecting section 32 is smaller than the outer diameter of the transmission section 31 and the outer diameter of the screw section 33. The outer diameter of the connecting section 32 is the smallest, so the transmission shaft 3 has better flexibility at the position of the connecting section 32, which is beneficial for absorbing the axial misalignment of the drive shaft 21 and the screw section 33 and avoiding stress concentration caused by rigid connection.

[0062] like Figure 3 and Figure 6As shown, to connect the transmission shaft 3 and the drive shaft 21, in some embodiments, the end of the transmission segment 31 away from the screw segment 33 includes a drive hole 311 recessed along the axial direction. The drive shaft 21 is accommodated in the drive hole 311. The cross-section of the drive hole 311 is non-circular. In this embodiment, the drive hole 311 can mate with the non-cylindrical drive shaft 21, and the shape fit between the drive shaft 21 and the drive hole 311 can prevent relative rotation between the drive shaft 21 and the transmission shaft 3 about the rotation axis. Alternatively, the transmission segment 31 may also include a first insertion hole 312 penetrating the transmission segment 31 perpendicular to the axial direction. Figure 3 As shown, in this embodiment, the drive shaft 21 includes a second insertion hole 211 extending through the drive shaft 21 perpendicular to the axial direction. The pump assembly 100 also includes a pin 5. The pin 5 is inserted into the first insertion hole 312 and the second insertion hole 211. The pin 5 restricts the relative movement of the drive end and the drive shaft 21 about the rotation axis and the relative movement along the axial direction Z. The drive hole 311 in this embodiment is simple to manufacture and can be adapted to various different motors 2, which helps to reduce the maintenance and repair costs of the pump assembly 100 in the later stages.

[0063] Since the pump assembly 100 is typically positioned so that the axial direction Z is parallel to the horizontal plane, the pin 5 inserted into the first socket 312 and the second socket 211 may, in a certain state, be parallel to the direction of gravity. Therefore, the pin 5 may disengage from the first socket 312 and the second socket 211 under the influence of gravity. To solve this problem, the pin 5 can, in fact, have an interference fit with at least one of the first socket 312 and the second socket 211. Alternatively, as... Figure 1 and Figure 3 As shown, the pump assembly 100 may include a sleeve 6. The sleeve 6 covers the outer periphery of the transmission section 31. The sleeve 6 is interference-fitted with the transmission section 31 and covers the first insertion hole 312. This arrangement allows the sleeve 6 to retain the pin 5 within the first insertion hole 312, thereby preventing relative movement between the drive shaft 21 and the transmission shaft 3 about their axial directions. Simultaneously, the sleeve 6 covering the outer periphery of the transmission section 31 also serves to shield the pin 5. This not only improves the aesthetics of the pump assembly 100 but also prevents potentially splashed corrosive fluids from damaging the pin 5, the transmission section 31, and the drive shaft 21.

[0064] In embodiments where both ends of the connecting cavity 121 are connected to the outside, the open connecting cavity 121 allows assembly personnel to easily insert the pins 5 and put on the protective sleeves 6 from both ends of the connecting cavity 121, facilitating operation and improving assembly efficiency. In addition, the open connecting cavity 121 also allows workers to easily observe the connection status of the drive shaft 21 and the transmission shaft 3, so that maintenance measures can be taken in a timely manner when they are disconnected.

[0065] In other embodiments, the drive shaft 21 may include a hole structure into which the transmission shaft 3 can be inserted. However, to prevent the torque generated by the drive shaft 21 from affecting the operation of the transmission shaft 3, in some alternative embodiments, the outer diameter of the transmission section 31 is larger than the outer diameter of the screw section 33. Since the outer diameters of the transmission section 31 and the screw section 33 are both larger than those of the connecting section 32, the outer diameter of the transmission section 31 is the largest in this embodiment. Increasing the outer diameter of the transmission section 31 improves its structural strength, thereby enabling it to withstand the torque generated by the rotation of the drive shaft 21 and preventing damage.

[0066] Combination Figure 2 , Figure 3 and Figure 5 The housing 1 includes a communicating hole 1112 connecting the liquid chamber 111 and the connecting chamber 121, allowing the transmission shaft 3 to enter the liquid chamber 111 after connecting the drive shaft 21 from the connecting chamber 121. Since the liquid chamber 111 contains fluid, there is a tendency for the fluid to flow out of the liquid chamber 111 through the communicating hole 1112. To achieve a seal for the fluid in the liquid chamber 111 and ensure that the fluid leaves the liquid chamber 111 from the outlet 1111 side, the pump assembly 100 of this application also includes a sealing structure 4. The sealing structure 4 is sleeved on the outer periphery of the transmission shaft 3. The sealing structure 4 is disposed in the communicating hole 1112 to prevent the fluid in the liquid chamber 111 from entering the connecting chamber 121 through the communicating hole 1112. The sealing structure 4 includes a dynamic sealing part 41 and a static sealing part 42.

[0067] The dynamic seal 41 forms an extremely thin liquid film as it rotates with the transmission shaft 3 to achieve a seal, thereby preventing fluid in the liquid chamber 111 from leaking along the transmission shaft 3 into the connecting chamber 121. It also prevents external air or other media from entering the liquid chamber 111 through the connecting hole 1112. The static seal 42 prevents fluid leakage through stationary connecting surfaces, ensuring that fluid flows only within the designed flow path. The combination of the dynamic seal 41 and the static seal 42 allows for fluid sealing of the liquid chamber 111 through various sealing methods, thereby improving the sealing performance of the pump assembly 100 against corrosive fluids, and ultimately increasing the service life and operational safety of the pump assembly 100.

[0068] It should be understood that the sealing structure 4 described in this application, which is sleeved on the transmission shaft 3, should be understood as the sealing structure 4 surrounding the outer periphery of the transmission shaft 3. It may be in direct contact with the transmission shaft 3, or it may be at a radial distance from the transmission shaft 3. Furthermore, the sealing structure 4 being sleeved on the outer periphery of the transmission shaft 3 can be understood as having direct contact with the outer peripheral surface of the transmission shaft 3. This description is not limited to the fit between the sealing structure 4 and the transmission shaft 3, but can also be applied to describe the positional relationship between any structure of the sealing structure 4 and the pump assembly 100.

[0069] refer to Figure 3The dynamic seal 41 includes a stationary ring 411 and a dynamic ring 412 sleeved on the transmission shaft 3. In some optional embodiments, the stationary ring 411 is connected to the inner wall of the housing 1. The dynamic ring 412 abuts against the end face of the stationary ring 411 facing the liquid outlet 1111. The dynamic ring 412 is connected to the transmission shaft 3 and rotates with the transmission shaft 3. If the connecting hole 1112 is understood as the leakage side, then in this embodiment, the dynamic ring 412 is placed on the side of the stationary ring 411 away from the leakage side, and a liquid film is formed on the side of the stationary ring 411 away from the leakage side by rotating relative to the stationary ring 411 to prevent fluid leakage. In this way, the sealed liquid film can be formed as far away from the leakage side as possible, preventing fluid from leaving the liquid chamber 111 directly through the connecting hole 1112 when the dynamic seal 41 fails.

[0070] Since the stationary sealing ring remains stationary, it will rotate relative to the stationary sealing ring around its axis during the rotation of the drive shaft. To avoid friction between the stationary sealing ring and the drive shaft, a gap exists between them. The dynamic sealing ring abuts against the end face of the stationary sealing ring facing the outlet 1111, thus preventing fluid from flowing into the gap between the stationary sealing ring and the drive shaft through the outer periphery of the dynamic sealing ring from the end face of the stationary sealing ring. However, to ensure the sealing effect of the pump assembly 100 at the communication hole 1112, the pump assembly 100 needs to prevent fluid from entering the communication hole 1112 and leaving the liquid chamber 111 through the gap between the stationary sealing ring and the housing 1. In some alternative embodiments, the stationary sealing portion 42 includes a first sealing ring 421. The first sealing ring 421 is fitted around the outer periphery of the stationary ring 411. The first sealing ring 421 is press-fitted against the inner wall of the housing 1. The first sealing ring 421 is fitted around the outer periphery of the stationary ring 411 and is interference-fitted with the inner wall of the housing 1. Therefore, the inner wall of the housing 1 presses the first sealing ring 421 against the outer periphery of the stationary ring 411, causing deformation. In this way, the first sealing ring 421 prevents fluid from leaving the liquid chamber 111 through the gap between the first sealing ring 421 and the stationary ring 411, and the gap between the first sealing ring 421 and the housing 1. It is evident that the cooperation between the moving ring 412 and the first sealing ring 421 achieves both dynamic and static sealing at the location of the stationary ring 411, allowing the stationary ring 411, located near the connecting hole 1112, to achieve better sealing. Compared to the interference fit between the stationary ring 411 and the housing 1, the first sealing ring 421 reduces the machining precision requirements for both the stationary ring 411 and the housing 1, and allows for easy replacement, thereby ensuring the sealing effect of the pump assembly 100.

[0071] The rotating ring 412 and the transmission shaft 3 can also be interference-fitted, preventing liquid from entering the gap between the rotating ring 412 and the transmission shaft 3, and allowing the rotating ring 412 to rotate with the transmission shaft 3. Alternatively, in some optional embodiments, the sealing structure 4 includes a limiting portion 43. The limiting portion 43 includes a rubber ring 431 fitted onto the transmission shaft 3. The rubber ring 431 includes a first end 4311 facing the outlet 1111 and a second end 4312 facing the connecting hole 1112. The first end 4311 is interference-fitted with the transmission shaft 3. The rubber ring 431 includes a limiting hole 4313 disposed at the second end 4312. The rotating ring 412 is disposed in the limiting hole 4313 and is interference-fitted with the limiting hole 4313. There is a gap between the rotating ring 412 and the surface of the transmission shaft 3. The material of the rubber ring 431 has a certain degree of corrosion resistance, and therefore can be used in the pump assembly 100 for pumping corrosive fluids. The material of the rubber ring 431 gives it a certain degree of elasticity and deformability, allowing assemblers to more easily assemble the first end 4311 with the transmission shaft 3 using an interference fit, and to assemble the rotating ring 412 into the limiting hole 4313 using an interference fit. Compared to the interference fit between the rotating ring 412 and the transmission shaft 3, this arrangement effectively reduces the machining accuracy requirements of the rotating ring 412 and the transmission shaft 3, thereby controlling production costs. Furthermore, the interference fit between the first end 4311 and the transmission shaft 3 prevents fluid from entering the gap between the rubber ring 431 and the transmission shaft 3 from the first end 4311. The rotating ring 412, located at the second end 4312, abuts against the stationary ring 411 to form a dynamic seal. Therefore, although there is a gap between the surfaces of the rotating ring 412 and the transmission shaft 3, fluid is also unlikely to enter the gap between the rotating ring 412 and the transmission shaft 3 through the second end 4312 of the rubber ring 431. It is evident that the rubber ring 431 can further improve the fluid sealing effect at the position of the moving ring 412.

[0072] Combination Figure 3 and Figure 6Although the first end 4311 of the rubber ring 431 is interference-fitted with the transmission shaft 3, in some optional embodiments, to prevent relative movement in the axial direction Z between the rubber ring 431 and the transmission shaft 3 due to prolonged use of the pump assembly 100, the limiting part 43 further includes a limiting member 432 adsorbently connected to the first end 4311 of the rubber ring 431. The transmission shaft 3 includes a keyway 34. The limiting member 432 includes a protrusion 4321 that mates with the keyway 34. The protrusion 4321 mates with the keyway 34 to allow the transmission shaft 3 to rotate the limiting member 432. The limiting member 432 restricts the position of the rubber ring 431 and the dynamic seal 41 in the axial direction Z and applies a force to the rubber ring 431 from the outlet 1111 towards the connecting hole 1112. The flexibility of the rubber ring 431 allows it to stably adhere to the limiting member 432 under fluid pressure, thus maintaining the relative positional relationship between the rubber ring 431 and the limiting member 432 along the axial direction Z. The engagement of the keyway 34 and the protrusion 4321 ensures that the rubber ring 431 remains relatively stationary around the rotation axis and rotates with the transmission shaft 3. Furthermore, since the first end 4311 of the rubber ring 431 adheres to the limiting member 432, the rubber ring 431 forms multiple sealing surfaces: the adhesion surface between the first end 4311 perpendicular to the axial direction Z and the limiting member 432, and the contact surface between the rubber ring 431 parallel to the axial direction Z and the transmission shaft 3. The engagement of the rubber ring 431 and the limiting member 432 further prevents fluid from entering the gap between the rubber ring 431 and the transmission shaft 3.

[0073] Combination Figure 3 and Figure 6 Optionally, the end of the transmission section 31 facing the connecting section 32 includes a boss 313. The end face of the boss 313 away from the connecting section 32 is used to abut against the sealing structure 4 of the pump assembly 100.

[0074] Optionally, the rubber ring 431 includes a deformable segment 4314 disposed between a first end 4311 and a second end 4312. The dimension of the deformable segment 4314 in the axial direction Z can be changed to alter the distance between the first end 4311 and the second end 4312 in the axial direction Z. At least a portion of the deformable segment 4314 has a gap with the wall of the transmission shaft 3. This gap between the deformable segment 4314 and the wall of the transmission shaft 3 allows the deformable segment 4314 sufficient space to move toward or away from the transmission shaft 3 as its dimension decreases in the axial direction Z, improving the feasible deformation of the deformable segment 4314. The rubber ring 431 needs to maintain the first end 4311 abutting against the limiting member 432, and the second end 4312 maintaining the moving ring 412 abutting against the stationary ring 411; therefore, the rubber ring 431 actually needs to meet certain dimensional requirements in the axial direction Z. The deformation section 4314 allows the limiting member 432 to apply a force from the outlet 1111 to the connecting hole 1112 to the rubber ring 431 when assembled with the transmission shaft 3. This keeps the rubber ring 431 holding the moving ring 412 against the stationary ring 411. When the moving ring 412 and the stationary ring 411 come into contact, the deformation section 4314 deforms, allowing the limiting member 432 to be assembled in place. After assembly, the deformation section 4314 tends to return to its original state. Therefore, it maintains a continuous force on the stationary ring 411 from the outlet 1111 to the connecting hole 1112, and maintains a force on the limiting member 432 from the connecting hole 1112 to the outlet 1111, thereby maintaining the sealing performance of the sealing structure 4.

[0075] Combination Figure 3 and Figure 4Optionally, the sealing structure 4 also includes a limiting ring 44. The limiting ring 44 includes an abutting end face 441 and a plurality of mating protrusions 442. The mating protrusions 442 are disposed on the side of the limiting ring 44 away from the abutting end face 441. Adjacent mating protrusions 442 form a mating groove 443 of the limiting ring 44. The limiting ring 44 is press-fitted with the rubber ring 431 on the side of the rubber ring 431 away from the transmission shaft 3. The limiting ring 44 includes two rings, namely a first ring 44a and a second ring 44b. The abutting end face 441 of the first ring 44a is disposed facing the first end 4311. The end face of the second ring 44b is disposed facing the second end 4312. When the mating protrusions 442 of the first ring 44a are inserted into the mating grooves 443 of the second ring 44b, the mating protrusions 442 of the second ring 44b are inserted into the mating grooves 443 of the first ring 44a. When the deformable segment 4314 is not deformed, there is a gap between the first ring 44a and the second ring 44b in the axial direction Z. The rubber ring 431 needs to be press-fitted with the transmission shaft 3; therefore, the limiting ring 44, fitted around the outer circumference of the rubber ring 431, press-fits with the rubber ring 431, causing the rubber ring 431 to deform perpendicular to the axial direction Z. This gives the rubber ring 431 a tendency to return to its original shape, thereby continuously applying pressure to the transmission shaft 3 and maintaining a tight fit with it. Furthermore, because the limiting ring 44 causes the rubber ring 431 to continuously apply pressure to the transmission shaft 3, the limiting ring 44 prevents displacement of the rubber ring 431 and the transmission shaft 3 in the axial direction Z, thus serving as an axial limit.

[0076] Furthermore, the engagement of the first ring 44a and the second ring 44b prevents the rubber ring 431 from deforming along the axial direction Z when the mating groove 443 of the two rings abuts against the mating protrusion 442. Therefore, the first ring 44a and the second ring 44b can also be used to control the minimum distance between the first end 4311 and the second end 4312.

[0077] In some optional embodiments, the retaining ring 44 is made of polyetheretherketone (PEEK). As mentioned above, PEEK has good chemical corrosion resistance, thus the retaining ring 44 located in the liquid cavity 111 can avoid corrosion caused by corrosive fluids. Furthermore, the PEEK retaining ring 44 has high mechanical strength and dimensional stability, thereby keeping the rubber ring 431 pressed tightly against the transmission shaft 3 without loosening. In addition, the PEEK material makes the retaining ring 44 lightweight, thereby reducing the dynamic balance burden when the transmission shaft 3 rotates. Compared to the structures of common springs and corrosion-resistant metals, the retaining ring 44 of this application can be paired, reducing the number of parts produced and the material cost. Of course, in other embodiments, the retaining ring 44 can also be made of other non-metallic materials.

[0078] In the above embodiments, the rotating ring 412 and the stationary ring 411 can also be made of non-metallic materials, thereby improving the chemical corrosion resistance of the dynamic seal 41. In some embodiments, the rotating ring 412 is a silicon carbide rotating ring 412. The stationary ring 411 is a silicon carbide stationary ring 411. Silicon carbide has good chemical corrosion resistance, so the dynamic seal 41 can be disposed in the liquid cavity 111 containing corrosive fluid, avoiding sealing failure caused by the corrosive fluid corroding the rotating ring 412 and the stationary ring 411. In addition, silicon carbide has good wear resistance, so it can also avoid damage when the rotating ring 412 and the stationary ring 411 rotate relative to each other, thereby maintaining the service life of the dynamic seal 41.

[0079] Combination Figure 3 and Figure 5 Optionally, the connecting hole 1112 includes a sealing unit 1112a and an abutting unit 1112b disposed in the liquid shell portion 11. The abutting unit 1112b is disposed between the sealing unit 1112a and the connecting cavity 121. The diameter of the sealing unit 1112a is larger than the diameter of the liquid cavity 111 and smaller than the diameter of the abutting unit 1112b. In other words, in the direction from the connecting cavity 121 to the liquid cavity 111, the diameters of the abutting unit 1112b, the sealing unit 1112a, and the liquid cavity 111 decrease sequentially. The shell 1 also includes a plenum portion 13. One end of the plenum portion 13 includes a flange 131. The flange 131 abuts against the abutting unit 1112b. The end of the plenum portion 13 away from the flange 131 extends into the connecting cavity 121. The transmission shaft 3 passes through the plenum portion 13. A dynamic sealing portion 41 is disposed on the side of the plenum facing the transmission shaft 3. A static seal 42 is provided in the sealing unit 1112a. The plenum 13 facilitates the assembly and connection of the dynamic seal 41, the connecting shell 12, and the transmission shaft 3. When assembling the pump assembly 100, the assembler first connects the dynamic seal 41 and the transmission section 31, then places the transmission shaft 3 in the liquid chamber 111, and fits the plenum 13 onto the outside of the transmission shaft 3. After connecting the transmission section 31 and the drive shaft 21, the plenum 13 is connected to the connecting shell 12, thereby sealing the liquid chamber 111. The static seal 42, located in the sealing unit 1112a, prevents fluid in the liquid chamber 111 from leaving the liquid chamber 111 through the gap between the plenum 13 and the liquid shell 11. Furthermore, the stepped arrangement of the sealing unit 1112a and the abutment unit 1112b, along with the engagement of the flange 131, increases the number of sealing surfaces of the plenum 13, further ensuring the fluid sealing performance of the pump assembly 100.

[0080] Combination Figure 4 and Figure 5In some optional embodiments, the end face of the plenum portion 13 facing the liquid cavity 111 includes a sealing protrusion 132. The sealing protrusion 132 cooperates with the sealing unit 1112a to form a sealed cavity 117 with an opening communicating with the liquid cavity 111. The static sealing portion 42 includes a second sealing ring. The second sealing ring is disposed in the sealed cavity 117 and is interference-fitted with the wall surface of the sealing unit 1112a. The dimension of the second sealing ring in the axial direction Z is smaller than the dimension of the sealed cavity 117 in the axial direction Z. The provision of the sealing protrusion 132 can reduce the flow area of ​​fluid flowing from the liquid cavity 111 into the sealed cavity 117, thereby reducing the possibility of fluid leakage. After the fluid enters the sealed cavity 117, the second sealing ring can perform a static sealing function, thereby further reducing the possibility of leakage at the location of the plenum portion 13.

[0081] Since the side of the plenum 13 facing the liquid cavity 111 may come into contact with the fluid in the liquid cavity 111, the plenum 13 also needs to have a certain degree of chemical corrosion resistance. In some optional embodiments, the plenum 13 is made of polytetrafluoroethylene (PTFE). PTFE can withstand strong acids, strong alkalis, and organic solvents, giving the transmission shaft 3 better chemical inertness and preventing corrosion. Furthermore, PTFE has good high-temperature resistance, which can prevent the heat generated by the motor 2 from negatively affecting the plenum 13, thereby improving the service life of the liquid shell 11.

[0082] Continue to refer to Figure 4 Similarly, in some embodiments where the liquid shell 11 includes an intake section 113 and a transition section 112, the end face of the intake section 113 facing the transition section 112 is provided with a receiving groove 1132. The receiving groove 1132 communicates with the liquid chamber 111. The end face of the transition section 112 facing the intake section 113 is provided with a receiving protrusion 1121. The receiving protrusion 1121 cooperates with the receiving groove 1132 to form a receiving cavity 116 with an opening communicating with the liquid chamber 111. In this embodiment, the static sealing part 42 includes a third sealing ring 423. The third sealing ring 423 is disposed in the receiving cavity 116 and is interference-fitted with the receiving groove 1132. The dimension of the third sealing ring 423 in the axial direction Z is smaller than the dimension of the receiving cavity 116 in the axial direction Z. With this arrangement, a fluid seal can be formed at the connection position of the intake section 113 and the transition section 112, preventing fluid leakage from the connection position of the intake section 113 and the transition section 112. Furthermore, compared to the embodiment where the intake section 113 and the transition section 112 are sealed by welding, this embodiment has a detachable connection between the intake section 113 and the transition section 112, which facilitates assembly and subsequent disassembly and maintenance.

[0083] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A pump assembly, characterized in that, include: The housing includes a communicating liquid cavity, a connecting cavity, a liquid outlet, and a communicating hole; the liquid outlet is located on the side of the liquid cavity away from the connecting cavity; the communicating hole connects the liquid cavity and the connecting cavity. A motor is connected to the housing on one side of the connecting cavity; the motor includes a drive shaft; the drive shaft extends into the connecting cavity; A transfer shaft is disposed in the liquid chamber and extends into the connecting chamber to be axially connected to the drive shaft; the drive shaft is used to drive the transfer shaft to rotate; the transfer shaft is used to drive the liquid in the liquid chamber to leave through the outlet by rotation; as well as, A sealing structure; at least a portion of the sealing structure is sleeved on the outer periphery of the transmission shaft and disposed in the communicating hole to prevent fluid in the liquid cavity from entering the connecting cavity through the communicating hole; the sealing structure includes a dynamic sealing part and a static sealing part.

2. The pump assembly according to claim 1, characterized in that, The dynamic sealing part includes: A stationary ring is fitted onto the transmission shaft; the stationary ring is connected to the inner wall of the housing; A moving ring is fitted onto the transmission shaft; the moving ring abuts against the end face of the stationary ring facing the liquid outlet; the moving ring is connected to the transmission shaft and rotates with the transmission shaft.

3. The pump assembly according to claim 2, characterized in that, The static sealing part includes a first sealing ring; the first sealing ring is sleeved on the outer periphery of the static ring; the first sealing ring is interference-fitted with the inner wall of the housing.

4. The pump assembly according to claim 2, characterized in that, The sealing structure includes a limiting part; the limiting part includes: A rubber ring includes a first end facing the liquid outlet and a second end facing the connecting hole; the rubber ring is sleeved on the transmission shaft; the first end is interference-fitted with the transmission shaft; the rubber ring includes a limiting hole disposed at the second end; a moving ring is disposed in the limiting hole and is interference-fitted with the limiting hole; there is a gap between the moving ring and the surface of the transmission shaft.

5. The pump assembly according to claim 4, characterized in that, The limiting part further includes: A limiting member is adsorbed and connected to the first end of the rubber ring; the transmission shaft includes a keyway; the limiting member includes a protrusion that mates with the keyway; the protrusion mates with the keyway to allow the transmission shaft to drive the limiting member to rotate; the limiting member is used to restrict the position of the rubber ring and the dynamic seal in the axial direction, and to apply a force to the rubber ring from the liquid outlet in the direction of the connecting hole.

6. The pump assembly according to claim 5, characterized in that, The rubber ring includes a deformable section disposed between the first end and the second end; the size of the deformable section in the axial direction is changeable to change the distance between the first end and the second end in the axial direction; at least a portion of the deformable section has a gap with the wall of the transmission shaft.

7. The pump assembly according to claim 6, characterized in that, The sealing structure further includes: A limiting ring includes an abutting end face and multiple mating protrusions; the mating protrusions are disposed on the side of the limiting ring away from the abutting end face; a mating groove of the limiting ring is formed between adjacent mating protrusions; the limiting ring is interference-fitted with the rubber ring on the side of the rubber ring away from the transmission shaft; the limiting ring includes two rings, namely a first ring and a second ring; The abutting end face of the first ring is disposed facing the first end; the end face of the second ring is disposed facing the second end; the mating protrusion of the first ring is inserted into the mating groove of the second ring; when the deformed segment is not deformed, there is a gap between the first ring and the second ring in the axial direction.

8. The pump assembly according to claim 7, characterized in that, The limiting ring is a polyetheretherketone limiting ring.

9. The pump assembly according to any one of claims 2-8, characterized in that, The moving ring is a silicon carbide moving ring; the stationary ring is a silicon carbide stationary ring.

10. The pump assembly according to claim 1, characterized in that, The housing includes a liquid housing portion and a connecting housing portion; the liquid cavity is disposed in the liquid housing portion; the connecting cavity is disposed in the connecting housing portion; the liquid outlet is disposed on the side of the liquid housing portion away from the connecting housing portion; a portion of the communicating hole is disposed in the liquid housing portion and the other portion is disposed in the connecting housing portion; The communicating hole includes a sealing unit and an abutment unit disposed on the liquid shell portion; the abutment unit is disposed between the sealing unit and the connecting cavity; the diameter of the sealing unit is larger than the diameter of the liquid cavity and smaller than the diameter of the abutment unit; wherein, The housing further includes a plenum portion; one end of the plenum portion includes a flange; the flange abuts against the abutting unit; the end of the plenum portion away from the flange extends into the connecting cavity; the transmission shaft passes through the plenum portion; the dynamic sealing portion is disposed on the side of the plenum portion facing the transmission shaft; the static sealing portion is disposed on the sealing unit.

11. The pump assembly according to claim 10, characterized in that, The end face of the plenum facing the liquid cavity includes a sealing protrusion; the sealing protrusion cooperates with the sealing unit to form a sealed cavity with an opening communicating with the liquid cavity; The static sealing part includes a second sealing ring; the second sealing ring is disposed in the sealing cavity and is interference-fitted with the wall surface of the sealing unit; the dimension of the second sealing ring in the axial direction is smaller than the dimension of the sealing cavity in the axial direction.

12. The pump assembly according to claim 10, characterized in that, The plenum is a polytetrafluoroethylene plenum.

13. The pump assembly according to claim 1, characterized in that, The housing includes a liquid housing portion and a connecting housing portion; the liquid cavity is disposed in the liquid housing portion; the connecting cavity is disposed in the connecting housing portion; the liquid outlet is disposed on the side of the liquid housing portion away from the connecting housing portion; a portion of the communicating hole is disposed in the liquid housing portion and another portion is disposed in the connecting housing portion; wherein... The connecting cavity is connected to the outside at both ends in a direction perpendicular to the axial direction.

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