US20250290493A1

US20250290493A1 - Dual-function liquid pump with integrated airflow control assembly

Info

Publication number: US20250290493A1
Application number: US19/221,199
Authority: US
Inventors: Heng-Yi Hsu
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-09-26
Filing date: 2025-05-28
Publication date: 2025-09-18

Abstract

A dual-function liquid pump with an integrated airflow control assembly is disclosed. The pump comprises a liquid reservoir configured to contain a liquid, a cover assembly removably coupled to the liquid reservoir, a pump cylinder coupled to the cover assembly, and a control valve disposed on the cover assembly. A liquid guide tube extends into the liquid reservoir. The pump cylinder defines a cylinder chamber in which a piston is disposed. Reciprocation of the piston enables air to be drawn out of or pumped into the liquid reservoir, thereby inducing liquid flow into the liquid reservoir through the liquid guide tube or discharging liquid from the liquid reservoir through the liquid guide tube.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 18/474,967, filed Sep. 26, 2023, the contents of which are incorporated herein by reference.

FIELD OF INVENTION

The present invention pertains to a device for extracting and delivering liquid. More particularly, the present invention relates to a dual-function liquid pump with an integrated airflow control assembly.

BACKGROUND OF THE INVENTION

A conventional dual-function liquid suction and discharge pump comprises a liquid reservoir, a cover assembly, a pump cylinder, and a control valve. The liquid reservoir defines an internal reservoir chamber configured to contain a liquid. The cover assembly is coupled to the liquid reservoir, and the pump cylinder is connected to the cover assembly and positioned within the reservoir chamber. The control valve is disposed on the cover assembly and situated externally relative to the liquid reservoir. The pump cylinder defines a cylinder chamber, within which a piston that permits unidirectional gas flow is disposed. The piston partitions the cylinder chamber into an upper chamber and a lower chamber. The piston is coupled to a shaft that extends through the cover assembly and is operably connected to a handle. Actuation of the handle causes the piston to reciprocate within the cylinder chamber, thereby varying the volumes of the upper chamber and the lower chamber. During this operation, air flows unidirectionally from the upper chamber, through the piston, into the lower chamber.
Adjustment of the control valve modifies the fluid communication among the cylinder chamber, the reservoir chamber, and an external environment. As a result, the control valve enables selective intake of an external liquid into the reservoir chamber or discharge of the liquid from the reservoir chamber.
However, the conventional dual-function liquid suction and discharge pump exhibits a complex configuration. During actuation of the pump cylinder to establish either a positive or negative pressure within the reservoir chamber, the piston restricts airflow such that air may only travel from the upper chamber through the piston to the lower chamber. This unidirectional constraint imposed by the piston adversely affects the efficiency of liquid pumping. Moreover, repeated reciprocation of the piston over extended periods can diminish the piston's capacity to maintain an effective airtight seal, thereby compromising the unidirectional gas barrier.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a dual-function liquid pump with an integrated airflow control assembly. To achieve this objective, the present invention employs the following technical solution:

- a liquid reservoir defining a reservoir chamber, the reservoir chamber extending to a top edge of the liquid reservoir to form a reservoir opening;
- a liquid guide tube extending into the reservoir chamber and configured to guide a liquid into or out of the reservoir chamber;
- a cover assembly removably coupled to the liquid reservoir and configured to seal the reservoir opening;
- a first air conduit, a second air conduit, and a third air conduit respectively connected to the cover assembly and disposed within the reservoir chamber;
- an air passage formed in the cover assembly and communicating the reservoir chamber with an external environment;
- a pump cylinder disposed within the reservoir chamber and coupled to the cover assembly, the pump cylinder defining a cylinder chamber;
- a piston disposed within the cylinder chamber and dividing the cylinder chamber into an upper chamber and a lower chamber, the piston obstructing communication between the upper chamber and the lower chamber, the upper chamber being in fluid communication with the air passage to allow air to enter or exit the upper chamber through the air passage;
- a shaft coupled to the piston and extending through the cover assembly, a handle being connected to the shaft to enable reciprocating movement of the piston within the cylinder chamber, thereby altering volumes of the upper chamber and the lower chamber;
- a first one-way valve disposed between the pump cylinder and the first air conduit and configured to allow air to flow only from the lower chamber to the first air conduit;
- a second one-way valve disposed between the pump cylinder and the second air conduit and configured to allow air to flow only from the second air conduit to the lower chamber; and
- a control valve comprising:
  - a valve housing coupled to the cover assembly and defining an elongated valve chamber, the valve chamber having opposite axial ends that are in communication with the external environment; an annular wall circumferentially surrounding the valve chamber in a radial direction; a first passage, a second passage, and a third passage, each in fluid communication with the valve chamber, the first, second, and third passages, along with the axial ends of the valve chamber, being spaced apart along an axial direction of the valve housing, with the third passage located between the first passage and the second passage; the first passage being in communication with the first air conduit, the second passage being in communication with the second air conduit, and the third passage being in communication with the reservoir chamber via the third air conduit; and
  - a valve rod disposed within the valve chamber and configured for axial reciprocal movement, the valve rod extending from both axial ends of the valve housing to define a first actuator end and a second actuator end, the valve rod carrying a first sealing ring, a second sealing ring, and a third sealing ring circumferentially thereon; the first sealing ring being located between the first passage and the first actuator end and selectively engageable with the annular wall to enable or prevent fluid communication between the first passage and the external environment via the valve chamber; the second sealing ring being located between the second passage and the second actuator end and selectively engageable with the annular wall to enable or prevent fluid communication between the second passage and the external environment via the valve chamber; and the third sealing ring being located between the first passage and the second passage and engaging the annular wall to selectively establish fluid communication between the third passage and either the first passage or the second passage via the valve chamber.

The principal advantage of the present invention lies in its streamlined and efficient configuration for air flow routing. During actuation of the pump cylinder to generate either positive or negative pressure within the reservoir chamber, air does not need to pass from the upper chamber through the piston to the lower chamber. Accordingly, the piston can be structurally simplified relative to that of conventional dual-function liquid suction and discharge pumps. This simplification enhances the piston's ability to effectively isolate air flow, extends its service life, and significantly improves the efficiency of liquid pumping.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a preferred embodiment of the a dual-function liquid pump of the present invention;

FIG. 2 is a perspective view of the preferred embodiment shown in FIG. 1 , depicted from an alternative angle with the liquid reservoir removed;

FIG. 3 is another perspective view of the preferred embodiment, further illustrating the configuration with the liquid reservoir removed;

FIG. 4 is a top view of the preferred embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 4 ;

FIG. 6 is a partially enlarged view of FIG. 5 , showing the configuration in which the shaft passes through the cover assembly;

FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 4 ;

FIG. 8 is a partially enlarged view of FIG. 7 , further detailing the structure of the control valve;

FIG. 9 is a first cross-sectional view (I) illustrating an operational state of the preferred embodiment, in which the valve rod is positioned as shown in FIG. 8 ;

FIG. 10 is a second cross-sectional view (II) of the first operational state of the preferred embodiment, again showing the valve rod in the position illustrated in FIG. 8 ;

FIG. 11 is a third cross-sectional view (III) of the first operational state, showing continued operation with the valve rod in the same position as shown in FIG. 8 ;

FIG. 12 is a partial cross-sectional view illustrating a second operational state of the preferred embodiment, with the valve rod shifted to an alternative position; and

FIG. 13 is a cross-sectional view of the second operational state, illustrating the operational behavior of the pump cylinder corresponding to the valve rod position shown in FIG. 12 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 through 8 , a preferred embodiment of a dual-function liquid pump comprises a liquid reservoir 10, a cover assembly 20, a pump cylinder 30, and a control valve 40. The liquid reservoir 10 defines an internal reservoir chamber 12, which extends to a top edge of the liquid reservoir 10 to form a reservoir opening 14. A liquid guide tube 50 extends into the reservoir chamber 12 and is configured to guide a liquid 90 into or out of the reservoir chamber 12.
The cover assembly 20 is removably coupled to the liquid reservoir 10 and is configured to seal the reservoir opening 14. A first air conduit 61, a second air conduit 62, and a third air conduit 63 are respectively connected to the cover assembly 20, with each of the first air conduit 61, the second air conduit 62, and the third air conduit 63 being positioned within the reservoir chamber 12. The cover assembly 20 further defines an air passage 22 that communicates the reservoir chamber 12 with an external environment.
The pump cylinder 30 is disposed within the reservoir chamber 12 and is coupled to the cover assembly 20. The pump cylinder 30 defines a cylinder chamber 32. A piston 34 is movably disposed within the cylinder chamber 32 and divides the cylinder chamber 32 into an upper chamber 322 and a lower chamber 324, while preventing fluid communication between the upper chamber 322 and the lower chamber 324. The upper chamber 322 is in fluid communication with the air passage 22, allowing air to enter or exit the upper chamber 322 through the air passage 22. The piston 34 is coupled to a shaft 36, which extends through the cover assembly 20 and is connected to a handle 38. Operation of the handle 38 causes the piston 34 to reciprocate within the cylinder chamber 32, thereby varying the volumes of the upper chamber 322 and the lower chamber 324. As the piston 34 reciprocates, air is drawn from the external environment through the air passage 22 into the upper chamber 322, and air within the upper chamber 322 is expelled through the air passage 22 to the external environment. More specifically, the air passage 22 is defined between a radial periphery of the shaft 36 and the inner surface of the cover assembly 20.
The first air conduit 61 and the second air conduit 62 are respectively connected to the pump cylinder 30. A first one-way valve 64 is disposed between the pump cylinder 30 and the first air conduit 61 and is configured to permit air flow exclusively from the lower chamber 324 to the first air conduit 61. A second one-way valve 65 is disposed between the pump cylinder 30 and the second air conduit 62 and is configured to permit air flow exclusively from the second air conduit 62 to the lower chamber 324. During the reciprocation of the piston 34, as the volume of the lower chamber 324 varies, air is drawn into the lower chamber 324 through the second air conduit 62 and the second one-way valve 65, and is subsequently expelled by the piston 34 through the first one-way valve 64 into the first air conduit 61. Air admitted into the first air conduit 61 is prevented from reentering the lower chamber 324 by the first one-way valve 64, and air entering the lower chamber 324 is prevented from backflow into the second air conduit 62 by the second one-way valve 65.
The first one-way valve 64 and the second one-way valve 65 may be implemented using conventional pipeline components configured to restrict the direction of fluid flow. The specific structures of the first one-way valve 64 and the second one-way valve 65 will not be described in further detail herein, and the illustrated examples should not be construed as limiting the configurations of such valves.
The control valve 40 comprises a valve housing 41 and a valve rod 42. The valve housing 41 is affixed to the cover assembly 20, thereby securely positioning the control valve 40 relative to the liquid reservoir 10. The valve housing 41 defines an elongated valve chamber 43, with opposing axial ends of the valve chamber 43 being open to and in communication with an external environment. The valve housing 41 further defines an annular wall 44, a first passage 45, a second passage 46, and a third passage 47. The annular wall 44 annularly surrounds the valve chamber 43 in a radial direction. The first passage 45, the second passage 46, and the third passage 47 each communicate with the valve chamber 43. The first passage 45, the second passage 46, the third passage 47, and the axial ends of the valve chamber 43 are arranged in an axially spaced configuration along the valve housing 41. The third passage 47 is located axially between the first passage 45 and the second passage 46. The first passage 45 is in fluid communication with the first air conduit 61, the second passage 46 is in fluid communication with the second air conduit 62, and the third passage 47 is in fluid communication with the reservoir chamber 12 via the third air conduit 63.
The valve rod 42 is disposed within the valve chamber 43 and is axially movable in a reciprocating manner. Opposing axial ends of the valve rod 42 extend beyond the valve housing 41 to form a first actuator end 421 and a second actuator end 422. The valve rod 42 is radially fitted with a first sealing ring 423, a second sealing ring 424, and a third sealing ring 425. The first sealing ring 423 is disposed between the first passage 45 and the first actuator end 421 and is configured to selectively engage or disengage the annular wall 44, thereby selectively enabling or preventing fluid communication between the first passage 45 and the external environment via the valve chamber 43. The second sealing ring 424 is disposed between the second passage 46 and the second actuator end 422 and is similarly configured to selectively engage or disengage the annular wall 44, thereby selectively enabling or preventing fluid communication between the second passage 46 and the external environment via the valve chamber 43. The third sealing ring 425 is disposed between the first passage 45 and the second passage 46 and is configured to engage the annular wall 44, thereby enabling the third passage 47 to selectively communicate with either the first passage 45 or the second passage 46 via the valve chamber 43.
Opposing axial ends of the valve housing 41 are respectively defined as a first axial end 412 and a second axial end 414. The first axial end 412 is positioned between the first passage 45 and the first actuator end 421, and the second axial end 414 is positioned between the second passage 46 and the second actuator end 422. The first axial end 412 and the second axial end 414 together define and limit the axial displacement stroke of the valve rod 42.
Referring to FIGS. 9, 10, and 11 , when the valve rod 42 is positioned as shown in FIG. 9 , the first actuator end 421 abuts the first axial end 412, and the first sealing ring 423 obstructs fluid communication between the first passage 45 and the first axial end 412. In this configuration, the third sealing ring 425 is positioned between the second passage 46 and the third passage 47. Consequently, the first air conduit 61 is in fluid communication with the reservoir chamber 12 through the first passage 45, the valve chamber 43, the third passage 47, and the third air conduit 63. Meanwhile, the second passage 46 is blocked from communicating with the third passage 47 through the valve chamber 43, but remains in communication with the external environment via the second axial end 414.
During reciprocation of the piston 34, operation of the handle 38 causes the piston 34 to move toward the cover assembly 20, thereby drawing external air through the second axial end 414 into the valve chamber 43. The air then flows sequentially through the second passage 46 and the second air conduit 62 into the lower chamber 324. When the piston 34 moves away from the cover assembly 20, the air in the lower chamber 324 is compressed by the piston 34 and forced through the first air conduit 61, the valve chamber 43, and the third air conduit 63 into the reservoir chamber 12. The resulting increase in air pressure within the reservoir chamber 12 drives the liquid 90 through the liquid guide tube 50 to the external environment.
Referring to FIGS. 12 and 13 , when the valve rod 42 is shifted to the position illustrated in FIG. 12 , the first actuator end 421 is displaced away from the first axial end 412, thereby allowing the first passage 45 to communicate with the external environment through the first axial end 412. In this state, the third sealing ring 425 is positioned between the first passage 45 and the third passage 47, blocking communication between the third passage 47 and the first passage 45 via the valve chamber 43. At the same time, the second actuator end 422 abuts the second axial end 414, and the second sealing ring 424 obstructs fluid communication between the second passage 46 and the second axial end 414. Accordingly, the reservoir chamber 12 is in fluid communication with the lower chamber 324 through the third air conduit 63, the third passage 47, the valve chamber 43, the second passage 46, and the second air conduit 62.
When the piston 34 is actuated via the handle 38 to move toward the cover assembly 20, air within the reservoir chamber 12 is drawn through the third air conduit 63, the valve chamber 43, and the second air conduit 62 into the lower chamber 324. This operation generates a negative pressure condition within the valve chamber 43, thereby inducing suction of the external liquid 90 into the reservoir chamber 12 through the liquid guide tube 50. When the piston 34 subsequently moves away from the cover assembly 20, air in the lower chamber 324 is expelled through the first air conduit 61, the valve chamber 43, and the first axial end 412 into the external environment.
The preferred embodiment provides a significantly simplified and more efficient air flow routing architecture. During the operation of the pump cylinder 30 to establish either positive or negative pressure within the reservoir chamber 12, air flows unidirectionally into the lower chamber 324 via the second air conduit 62 and is subsequently expelled unidirectionally into the first air conduit 61. The piston 34 functions as a bidirectional barrier between the upper chamber 322 and the lower chamber 324. This configuration eliminates the need for air to pass from the upper chamber 322 through the piston 34 into the lower chamber 324, as required in conventional designs wherein the piston must accommodate unidirectional gas flow. As such, the piston 34 of the preferred embodiment features a structurally simplified design that more effectively obstructs air flow, offers improved sealing durability, and substantially enhances the efficiency of liquid 90 pumping operations.
The preferred embodiment further provides a reduced air flow path length compared to prior art configurations, thereby minimizing pressure variations caused by frictional losses within the air delivery conduits and lowering the operational resistance of the pump. Moreover, since the first air conduit 61 and the second air conduit 62 are respectively configured to direct air out of and into the lower chamber 324, these air delivery conduits can be designed to have substantially identical path lengths. This symmetry ensures balanced airflow, thereby reducing the likelihood of flow rate imbalances or turbulence during pump operation.
The cover assembly 20, the pump cylinder 30, the control valve 40, the first air conduit 61, the second air conduit 62, and the third air conduit 63 together form an integrated airflow control assembly. This integrated assembly allows for simplified maintenance; for example, the liquid reservoir 10 can be easily removed from the cover assembly 20 for cleaning purposes without requiring further disassembly of the integrated assembly.
The integrated assembly may be matched with liquid reservoirs 10 of various volumes depending on specific application requirements, thereby forming a modular dual-function liquid pump. If the liquid reservoir 10 becomes damaged (e.g., by cracking or leakage), it may be replaced with a compatible liquid reservoir 10. The cover assembly 20, the pump cylinder 30, the control valve 40, the first air conduit 61, the second air conduit 62, and the third air conduit 63 may all be retained and reused, further enhancing the cost-effectiveness and serviceability of the invention.
A distance between the first sealing ring 423 and the second sealing ring 424 is greater than a distance between the first passage 45 and the second passage 46. This geometric relationship ensures proper positioning and sealing engagement of the sealing rings relative to the ring wall 44 within the valve housing 41 during axial displacement of the valve rod 42.
The valve housing 41 further defines a first auxiliary chamber 48 and a second auxiliary chamber 49, both of which communicate with the valve chamber 43. The first auxiliary chamber 48 is disposed between the first passage 45 and the first axial end 412 and extends to the first axial end 412. Similarly, the second auxiliary chamber 49 is disposed between the second passage 46 and the second axial end 414 and extends to the second axial end 414. The internal diameter of the first auxiliary chamber 48 is greater than the external diameter of the first sealing ring 423 in its uncompressed state, and the internal diameter of the second auxiliary chamber 49 is likewise greater than the external diameter of the second sealing ring 424 in its uncompressed state.
When the first sealing ring 423 moves axially from the valve chamber 43 into the first auxiliary chamber 48, the valve chamber 43 becomes fluidly connected to the external environment through the first auxiliary chamber 48. Similarly, when the second sealing ring 424 is displaced from the valve chamber 43 into the second auxiliary chamber 49, the valve chamber 43 becomes fluidly connected to the external environment through the second auxiliary chamber 49.
The cover assembly 20 is further provided with a connection conduit 24 that is in fluid communication with the liquid guide tube 50. The liquid 90 is thereby permitted to flow into or out of the reservoir chamber 12 through a flow path comprising the liquid guide tube 50 and the connection conduit 24. The connection conduit 24 may be adapted to connect with a pipe fitting 92, enabling the liquid 90 to be introduced into or discharged from the reservoir chamber 12 via the pipe fitting 92.

Claims

What is claimed is:

1. A dual-function liquid pump, comprising:

a liquid reservoir defining a reservoir chamber, the reservoir chamber extending to a top edge of the liquid reservoir to form a reservoir opening;

a liquid guide tube extending into the reservoir chamber and configured to guide a liquid into or out of the reservoir chamber;

a cover assembly removably coupled to the liquid reservoir and configured to seal the reservoir opening;

a first air conduit, a second air conduit, and a third air conduit respectively connected to the cover assembly and disposed within the reservoir chamber;

an air passage formed in the cover assembly and communicating the reservoir chamber with an external environment;

a pump cylinder disposed within the reservoir chamber and coupled to the cover assembly, the pump cylinder defining a cylinder chamber;

a piston disposed within the cylinder chamber and dividing the cylinder chamber into an upper chamber and a lower chamber, the piston obstructing communication between the upper chamber and the lower chamber, the upper chamber being in fluid communication with the air passage to allow air to enter or exit the upper chamber through the air passage;

a shaft coupled to the piston and extending through the cover assembly, a handle being connected to the shaft to enable reciprocating movement of the piston within the cylinder chamber, thereby altering volumes of the upper chamber and the lower chamber;

a first one-way valve disposed between the pump cylinder and the first air conduit and configured to allow air to flow only from the lower chamber to the first air conduit;

a second one-way valve disposed between the pump cylinder and the second air conduit and configured to allow air to flow only from the second air conduit to the lower chamber; and

a control valve comprising:

a valve housing coupled to the cover assembly and defining an elongated valve chamber, the valve chamber having opposite axial ends that are in communication with the external environment; an annular wall circumferentially surrounding the valve chamber in a radial direction; a first passage, a second passage, and a third passage, each in fluid communication with the valve chamber, the first, second, and third passages, along with the axial ends of the valve chamber, being spaced apart along an axial direction of the valve housing, with the third passage located between the first passage and the second passage; the first passage being in communication with the first air conduit, the second passage being in communication with the second air conduit, and the third passage being in communication with the reservoir chamber via the third air conduit; and

a valve rod disposed within the valve chamber and configured for axial reciprocal movement, the valve rod extending from both axial ends of the valve housing to define a first actuator end and a second actuator end, the valve rod carrying a first sealing ring, a second sealing ring, and a third sealing ring circumferentially thereon; the first sealing ring being located between the first passage and the first actuator end and selectively engageable with the annular wall to enable or prevent fluid communication between the first passage and the external environment via the valve chamber; the second sealing ring being located between the second passage and the second actuator end and selectively engageable with the annular wall to enable or prevent fluid communication between the second passage and the external environment via the valve chamber; and the third sealing ring being located between the first passage and the second passage and engaging the annular wall to selectively establish fluid communication between the third passage and either the first passage or the second passage via the valve chamber.

2. The dual-function liquid pump of claim 1, wherein a distance between the first sealing ring and the second sealing ring is greater than a distance between the first passage and the second passage.

3. The dual-function liquid pump of claim 1, wherein:

the valve housing further defines a first axial end and a second axial end, the first axial end being positioned between the first passage and the first actuator end, and the second axial end being positioned between the second passage and the second actuator end;

a first auxiliary chamber, in fluid communication with the valve chamber, is defined between the first passage and the first axial end and extends to the first axial end;

a second auxiliary chamber, in fluid communication with the valve chamber, is defined between the second passage and the second axial end and extends to the second axial end; and

an inner diameter of each of the first auxiliary chamber and the second auxiliary chamber is greater than an outer diameter of the corresponding first or second sealing ring in an uncompressed state.

4. The dual-function liquid pump of claim 1, wherein the cover assembly further comprises a connection conduit in fluid communication with the liquid guide tube, the connection conduit being configured to allow the liquid to enter or exit the reservoir chamber through the liquid guide tube and the connection conduit.

5. An integrated airflow control assembly for forming a dual-function liquid pump, the integrated assembly being configured to couple with a liquid reservoir, the integrated assembly comprising:

a cover assembly configured for coupling to the liquid reservoir;

a first air conduit, a second air conduit, and a third air conduit, each connected to the cover assembly;

an air passage formed in the cover assembly and configured to communicate with the external environment;

a pump cylinder coupled to the cover assembly and defining a cylinder chamber therein;

a piston disposed within the cylinder chamber and dividing the cylinder chamber into an upper chamber and a lower chamber, the piston obstructing fluid communication between the upper chamber and the lower chamber, the upper chamber being in fluid communication with the air passage to allow air to enter or exit the upper chamber;

a shaft coupled to the piston and extending through the cover assembly, a handle being connected to the shaft to enable reciprocating movement of the piston and thereby vary the volumes of the upper chamber and the lower chamber;

a first one-way valve disposed between the pump cylinder and the first air conduit, the first one-way valve being configured to allow air to flow only from the lower chamber to the first air conduit;

a second one-way valve disposed between the pump cylinder and the second air conduit, the second one-way valve being configured to allow air to flow only from the second air conduit to the lower chamber; and

a control valve comprising:

a valve housing coupled to the cover assembly and defining an elongated valve chamber, the valve chamber having opposite axial ends that are in communication with the external environment; an annular wall circumferentially surrounding the valve chamber in a radial direction; a first passage, a second passage, and a third passage, each in fluid communication with the valve chamber, the first, second, and third passages, along with the axial ends of the valve chamber, being spaced apart along an axial direction of the valve housing, with the third passage located between the first passage and the second passage; the first passage being in communication with the first air conduit, the second passage being in communication with the second air conduit, and the third passage being in communication with the third air conduit;

and a valve rod disposed within the valve chamber and configured for axial reciprocal movement, the valve rod extending from both axial ends of the valve housing to define a first actuator end and a second actuator end, the valve rod carrying a first sealing ring, a second sealing ring, and a third sealing ring circumferentially thereon; the first sealing ring being located between the first passage and the first actuator end and selectively engageable with the annular wall to enable or prevent fluid communication between the first passage and the external environment via the valve chamber; the second sealing ring being located between the second passage and the second actuator end and selectively engageable with the annular wall to enable or prevent fluid communication between the second passage and the external environment via the valve chamber; and the third sealing ring being located between the first passage and the second passage and engaging the annular wall to selectively establish fluid communication between the third passage and either the first passage or the second passage via the valve chamber.

6. The integrated airflow control assembly of claim 5, wherein a distance between the first sealing ring and the second sealing ring is greater than a distance between the first passage and the second passage.

7. The integrated airflow control assembly of claim 5, wherein:

8. The integrated airflow control assembly of claim 5, wherein the cover assembly further comprises a connection conduit configured for fluid communication with the liquid reservoir, the connection conduit being configured to allow liquid to enter or exit the liquid reservoir.