Liquid discharge device

Abstract

The present invention relates to a liquid discharge device comprising: a liquid pump unit; and a driving unit coupled to the liquid pump unit so as to provide a driving force, wherein the liquid pump unit comprises: a rotor part having a male screw shape; a stator part accommodating at least a portion of the rotor part and having a female screw shape; a housing part surrounding the rotor part and the stator part and having an inner accommodation space formed to allow a liquid to flow; and a power transmission part which transmits a motor driving force of the driving unit to the rotor part, is fixed and coupled to the housing part, and is detachably coupled to the driving unit, and the liquid pump unit is detachably coupled to the driving unit so as to be integrally replaceable.

Description

Liquid discharge device

[0001] The present invention relates to a liquid discharge device, and more particularly, to a liquid discharge device including a liquid pump unit of a progressive cavity pump (PC pump) type.

[0002] Cross-reference to related applications

[0003] This application claims priority to Republic of Korea Patent Application No. 10-2024-0114301, filed August 26, 2024, the entire contents of which are incorporated herein by reference.

[0004]

[0005] [National Research and Development Project Supporting This Invention]

[0006] [Project ID]1711179412

[0007] [Assignment Number] 00141157

[0008] [Buddha Name] Many Buddhas

[0009] [Name of Project Management (Specialist) Institution] (Foundation) Inter-Ministry Full-cycle Medical Device Research and Development Project Group

[0010] [Research Project Name] Inter-Ministry Full-cycle Medical Device Research and Development (Ministry of Science and ICT, Ministry of Trade, Industry and Energy, Ministry of Health and Welfare)

[0011] [Research Project Name] Development of a Mobile Hemodialysis Medical Device with Remote Monitoring

[0012] [Name of the project performing organization] Synopex Co., Ltd.

[0013] Research Period: April 1, 2022 - December 31, 2025

[0014]

[0015] A progressive cavity pump (PC pump), a type of liquid dispensing device, is a pump comprising a stator and a rotor, which moves a constant volume of liquid relative to the rotational angle of the rotor. Because these progressive cavity pumps eliminate liquid pulsation, they can precisely match the rotor rotation speed and the dispensing volume. Therefore, they are widely used in various fields, including molding, bonding, sealing, and material mixing operations in the manufacturing of automobiles, semiconductors, optical products, and general home appliances.

[0016] However, the progressive cavity pump is often used semi-permanently, as the rotor is directly connected to the motor shaft and components such as universal joints, making separation difficult. Consequently, it cannot be used in applications where liquid-contacting components cannot be reused due to chemical properties such as liquid toxicity and must be discarded, or where hygiene and infection prevention are paramount, necessitating replacement of liquid-contacting components.

[0017] In particular, in the medical field, for drug delivery pumps, although it is very important to quantitatively deliver a set flow rate of drug to a patient, there is a problem in that progressive cavity pumps cannot be used due to concerns about infection.

[0018] The present invention provides a liquid dispensing device that is hygienic, easy to replace, and has a simple structure while quantitatively delivering a drug to a patient.

[0019] The present invention provides a liquid discharge device comprising: a liquid pump unit; and a drive unit coupled to the liquid pump unit to provide a driving force; the liquid pump unit comprises: a rotor part having a male screw shape; a stator part having a female screw shape and accommodating at least a portion of the rotor part; a housing part surrounding the rotor part and the stator part and having an internal receiving space in which a liquid flows; and a power transmission part that transmits a motor driving force of the drive unit to the rotor part, is fixedly coupled to the housing part, and is detachably coupled to the drive unit; the liquid pump unit is detachably coupled to the drive unit so as to be replaceable as a single unit.

[0020] The power transmission unit may have a first connection formed on one side to which an end of the rotor unit is connected, and a second connection formed on the other side to which a motor rotation shaft of the drive unit is directly or indirectly connected.

[0021] The rotor section includes a head section in the shape of a male screw placed in the hollow of the stator section; a body section having one end connected to the head section and the other end connected to the power transmission section; and at least one protrusion formed protruding from the outer surface of the body section; and at least one groove may be formed on the outer surface of the protrusion section.

[0022] The above groove may be formed in a spiral shape along the circumferential direction of the above protrusion.

[0023] The above head portion, the body portion, and the protrusion portion are formed of a synthetic resin material and can be integrally injection-molded.

[0024] The housing part may include a first housing part that is coupled to the power transmission part and has a liquid supply part formed therein that receives liquid from the outside; and a second housing part that is coupled to the first housing part and has a liquid discharge part formed therein that discharges liquid to the outside.

[0025] The above liquid pump unit is disposed in the internal receiving space of the housing portion and may further include at least one sealing portion surrounding a portion of the outer circumference of the rotor portion.

[0026] The above driving unit may include a motor receiving portion that receives the motor; and a bridge portion provided on an upper portion of the motor receiving portion and connecting the motor receiving portion and the liquid pump unit.

[0027] The liquid discharge device according to the present invention may further include a cover unit that is coupled to the upper portion of the liquid pump unit and fixes the liquid pump unit to the drive unit.

[0028] The above cover unit and the above liquid pump unit can be slidably fitted into the drive unit.

[0029] The present invention has the advantage of enabling use as a drug infusion pump in medical fields where it was not previously possible to use it, since the entire liquid pump unit can be easily removed and newly installed by modularizing it into a consumable form.

[0030] In addition, the present invention has the advantage of enabling liquid transport using a progressive cavity pump method even in situations where the liquid to be transported is toxic or the parts that have come into contact with the liquid cannot be reused due to chemical properties, by modularizing the liquid pump unit into a consumable form.

[0031] In addition, the present invention provides liquid discharge performance at the same level as a conventional progressive cavity pump, while configuring the liquid pump unit to enable eccentric movement of the rotor section without parts such as a flexible shaft or universal joint, thereby making it structurally simple, easy to implement, and easy to manufacture, thereby maximizing its advantages as a consumable.

[0032] Figure 1 is a schematic perspective view of a liquid discharge device according to the present invention.

[0033] Figure 2 is a schematic exploded perspective view of the liquid discharge device of Figure 1.

[0034] Figure 3 is a schematic exploded perspective view of the liquid discharge device of Figure 1 viewed from another direction.

[0035] FIG. 4 is a schematic side view of the liquid pump unit showing the liquid pump unit in more detail in the liquid discharge device of FIG. 1.

[0036] Figure 5a is a schematic cross-sectional view of the liquid pump unit of Figure 4.

[0037] Fig. 5b is a schematic cross-sectional view showing the appearance of the rotor section while rotating in the liquid pump unit of Fig. 4.

[0038] Fig. 6a is a schematic side view of the rotor section in the liquid pump unit of Fig. 5a showing the rotor section in detail.

[0039] Figure 6b is a schematic side view of a rotor section showing another embodiment of the rotor section of the present invention.

[0040] FIG. 6c is a schematic side view of a rotor section showing another embodiment of the rotor section of the present invention.

[0041] Figure 7 is a graph showing the performance of a liquid discharge device according to the present invention.

[0042] The present invention provides a liquid discharge device (10) comprising a replaceable liquid pump unit (100) composed of consumables.

[0043] The liquid discharge device (10), as illustrated in FIG. 1, includes a liquid pump unit (100); a driving unit (200) coupled to the liquid pump unit (100) to provide driving force; and a cover unit (300) coupled to the upper portion of the liquid pump unit (100). In the present invention, the meanings of upper and lower portions can be understood as an area close to the upper portion of the drawing in the components as upper portions, and an area close to the lower portion of the drawing as lower portions, based on the drawing of FIG. 3.

[0044] Specifically, the liquid discharge device (10) has a structure in which a liquid pump unit (100), a drive unit (200), and a cover unit (300) are combined, and the liquid pump unit (100) is configured as a consumable and is provided to be replaceable from the drive unit (200).

[0045] The above liquid pump unit (100) has the function of a progressive cavity pump and is detachably provided on the drive unit (200) so that the entire unit can be replaced as a single unit, as shown in FIGS. 2 and 3.

[0046] That is, the liquid pump unit (100) can be replaced in the form of a consumable in a modular configuration as illustrated in FIG. 4, and can be used and discarded after being mounted on the drive unit (200). Accordingly, the liquid pump unit (100) can be used as a drug infusion pump in the medical field where hygiene and infection prevention must be met as top priorities, and it enables liquid transport using the PC pump method even in situations where parts that have come into contact with the liquid cannot be reused due to the toxicity or other chemical properties of the liquid to be transported.

[0047] In addition, the liquid pump unit (100) is replaced as a whole, so that it has the advantage of preventing problems such as leakage between the stator and the rotor due to the replaced stator not being in close contact with the rotor by replacing only the stator in a conventional progressive cavity pump, or the normal operating range being reduced due to sensitivity to the operating environment.

[0048] Specifically, the liquid pump unit (100) includes a rotor part (110) having a male screw shape; a stator part (120) having a female screw shape and accommodating at least a portion of the rotor part (110); a housing part (130) surrounding the rotor part (110) and the stator part (120) and having an internal receiving space in which a liquid flows; and a power transmission part (140) that transmits the motor driving force of the driving unit (200) to the rotor part (110), is fixedly coupled to the housing part (130), and is detachably coupled to the driving unit (200).

[0049] The above rotor part (110) has a screw shape, receives driving force from the motor of the driving unit (200), and rotates eccentrically with respect to the motor rotation axis of the driving unit (200).

[0050] When the rotor section (110) rotates in the hollow of the stator section (120), the center of the cross-section of the rotor section (110) moves in a hypocycloid trajectory of an integer ratio determined by the number of threads of the screw shape of the stator section (120). Accordingly, the liquid is transported through the cavity between the stator section (120) and the rotor section (110) by the eccentrically rotating rotor section (110).

[0051] The rotor part (110) includes, as shown in FIGS. 5a and 5b, a head part (111) in the shape of a male screw placed in the hollow of the stator part (120); a body part (112) having one end connected to the head part (111) and the other end connected to the power transmission part (140); and at least one protrusion (113) formed to protrude from the outer surface of the body part (112).

[0052] The above head portion (111), body portion (112), and protrusion portion (113) are formed of a synthetic resin material and are integrally injection-molded. The synthetic resin material is preferably selected from a material having high hardness and strength among synthetic resins, such as formlabs tough 2000 resin, so that the liquid pump unit (100) can have the same level of performance as a conventional progressive cavity pump and can withstand corrosion and wear. The formlabs tough 2000 resin material has high hardness and strength with properties similar to ABS plastic, so that it is somewhat stiff, but also has a certain level of elasticity.

[0053] Accordingly, the rotor unit (110) can be manufactured as a single unit through injection molding or 3D printing. Furthermore, when the liquid pump unit (100) is replaced as a consumable, the hassle of assembling or disassembling additional components, such as universal joints, to the rotor unit (110) can be eliminated.

[0054] However, the head portion (111) may be formed of a different material from the body portion (112) and the protrusion (113) and may be combined. For example, the body portion (112) and the protrusion (113) may be formed of a synthetic resin material, but the head portion (111) may be formed of a stainless steel material to prevent wear and corrosion.

[0055] Meanwhile, the structure of the head portion (111), body portion (112), and protrusion portion (113) will be specifically described below based on FIGS. 5a and 5b.

[0056] The head portion (111), as illustrated in FIG. 5A, has a male screw shape and is placed in the inner hollow of the stator portion (120). The head portion (111) has a screw shape that is one line less than the female screw shape of the stator portion (120). For example, when the stator portion (120) has a female screw shape in the form of a two-line screw, the head portion (111) has a male screw shape in the form of a single-line screw.

[0057] Accordingly, regular spiral spaces are created between the head portion (111) and the stator portion (120) according to the rotation of the rotor portion (110), and the liquid in the internal storage space of the housing portion (130) moves forward in the open direction of the housing portion (130) according to the rotation of the rotor portion (110) and is discharged to the outside.

[0058] The body part (112) has one end connected to the head part (111) and the other end connected to the power transmission part (140), and at least one protrusion (113) is formed on the outer surface of the body part (112).

[0059] The above protrusion (113) is formed to protrude from the outer surface of the body portion (112) and is formed to protrude along the circumferential direction of the body portion (112). Since at least one groove (113a) is formed in the protrusion (113) along the circumferential direction of the protrusion (113), the present invention can provide elasticity to the rotor portion (110) as a whole to implement nonlinear power transmission.

[0060] That is, even if the rotor part (110) is manufactured as an integral structure using a synthetic resin having high hardness and strength, the present invention can enable nonlinear power transmission of the rotor part (110) through the groove (113a) formed in the protrusion (113). Accordingly, the rotor part (110) of the present invention does not require parts such as a flexible shaft or a universal joint in implementing nonlinear power transmission. This is because the groove (113a) formed in the circumferential direction of the protrusion (113) can repeatedly narrow and widen while the rotor part (110) rotates.

[0061] That is, as illustrated in FIG. 5b, as the width (w) of the groove (113a) formed in the circumferential direction of the protrusion (113) repeatedly narrows and widens while the rotor part (110) rotates, the protrusion (113) bends due to elasticity, so that the body part (112) bends and moves in the internal receiving space of the housing part (130). Accordingly, the body part (112) can effectively transmit the driving force of the motor to the rotor part (110), while allowing the rotor part (110) to move eccentrically with respect to the motor rotation axis of the drive unit (200).

[0062] In particular, the present invention has a feature of improving the structural stability of the rotor part (111) by not directly forming a groove on the outer surface of the body part (112), but additionally providing a protrusion (113) on the body part (112), and then forming a groove (113a) on the protrusion (113). If a groove is directly formed on the outer surface of the body part (112) without the protrusion (113), the body part (112) becomes prone to breaking, and since the diameter of the body part (112) is small, it is difficult to form the groove deeply.

[0063] This protrusion (113) may be formed so that one side thereof is inclined from the body portion (112). For example, as illustrated in FIGS. 6A and 6C, the protrusion (113) may be formed so that one side thereof, which is closer to the sealing portion (150) described later, is tapered. In this case, since the width (w) between the grooves (113a) of the protrusion (113) narrows or widens depending on the rotation of the rotor portion (110), when the body portion (112) bends, interference with the sealing portion (150) can be minimized, and accordingly, the body portion (112) can effectively transmit the rotation of the motor to the head portion (111).

[0064] In addition, as illustrated in FIG. 6b, when the protrusions (113) are formed in two, the protrusions (113) may be formed in a tapered and inclined shape so that the surfaces facing each other are each inclined. In this case, when the width (w) of the groove (113a) of the protrusion (113) narrows or widens according to the rotation of the rotor (110), and the body (112) bends, interference between the protrusions (113) can be minimized, and accordingly, the body (112) can effectively transmit the rotation of the motor to the head (111).

[0065] The above protrusions (113) may be formed in the body portion (112) in at least one form, and when formed in multiple forms, the protrusions (113) may be spaced apart from each other along the longitudinal direction of the body portion (112). For example, as illustrated in FIG. 6b, two protrusions (113) may be formed in the body portion (112) in a spaced-apart manner along the longitudinal direction of the body portion (112).

[0066] Meanwhile, the groove (113a) formed in the protrusion (113) may be formed in various shapes. For example, the groove (113a) may be formed in an oblique spiral shape along the circumferential direction of the protrusion (113), as illustrated in FIGS. 6A and 6B, and may be formed to surround the outer circumferential surface of the protrusion (113). As another example, the groove (113a) may be formed in a straight line perpendicular to the longitudinal direction of the protrusion (113) along the circumferential direction of the protrusion (113), as illustrated in FIG. 6C.

[0067] The above groove (113a) may be formed in various numbers. For example, when the groove (113a) is formed as one, the groove (113a) may be formed to surround the entire outer surface of the protrusion (113) in the circumferential direction of the protrusion (113). In addition, when the groove (113a) is formed as a plurality of grooves, some of the plurality of grooves (113a) may be formed along the circumferential direction of the protrusion (113) on one side of the protrusion (113), and the remainder of the plurality of grooves (113a) may be formed along the circumferential direction of the protrusion (113) on the other side of the protrusion (113).

[0068] By adjusting the shape and number of the aforementioned grooves (113a), as well as the width (w), depth, size, etc. of the grooves (113a), the degree of bending deformation of the body part (112), the degree of rotation of the head part (111), etc. can be adjusted.

[0069] Accordingly, the present invention can provide a liquid pump unit (100) that is structurally simple and easy to manufacture because, unlike a conventional progressive cavity pump, it does not require additional parts such as a universal joint and a flexible shaft, thereby maximizing the advantages of the liquid pump unit (100) as a consumable.

[0070] Meanwhile, the stator section (120) accommodates at least a portion of the rotor section (110) and has a female screw shape, and may be made of an elastomer material.

[0071] The stator part (120) is fitted and fixed inside the second housing part (132) described later. Referring again to FIG. 5a, the stator part (120) has a head part (111) in the shape of a male screw, which is a part of the rotor part (110), placed in the inner hollow space, and the liquid is discharged to the outside through the hollow space of the stator part (120).

[0072] Meanwhile, the housing portion (130) surrounds the rotor portion (110) and the stator portion (120), and has a hollow space formed through which liquid flows. The housing portion can be formed of plastic and manufactured by injection molding or 3D printing.

[0073] Specifically, the housing part (130) includes a first housing part (131) that is coupled with the power transmission part (140) and has a liquid supply part (131a) formed therein that receives liquid from the outside; and a second housing part (132) that is coupled with the first housing part (131) and has a liquid discharge part (132a) formed therein that discharges liquid to the outside.

[0074] Specifically, the first housing part (131) is coupled with the power transmission part (140), and a liquid supply part (131a) that receives liquid from the outside is formed, and the body part (112) and the protrusion part (113) of the rotor part (110) described above are arranged together with the liquid in the internal receiving space. In addition, the liquid supply part (131a) is formed on the upper side of the first housing part (131) and can supply liquid from the outside to the internal receiving space of the first housing part (131).

[0075] Meanwhile, the second housing part (132) is coupled with the first housing part (131) and has a liquid discharge part (132a) formed therein for discharging liquid to the outside, and the head part (111) of the stator part (120) and rotor part (110) described above are arranged together with liquid in the internal receiving space. In addition, the liquid discharge part (132a) is formed on the side of the second housing part (132) and can discharge liquid to the outside from the internal receiving space of the second housing part (132).

[0076] The second housing part (132) shares an internal receiving space with the first housing part (131), and the liquid supplied from the liquid supply part (131a) of the first housing part (131) moves through the internal receiving space of the first housing part (131) to the internal receiving space of the second housing part (132), and is delivered to the liquid discharge part (132a) and discharged to the outside according to the rotation of the rotor part (110). In addition, the second housing part (132) and the first housing part (131) can be detachably coupled to each other.

[0077] Meanwhile, as illustrated in FIG. 5A, the first housing portion (131) has an end coupled to the power transmission portion (140). In addition, a through hole is formed at the end of the first housing portion (131) through which the end of the rotor portion (110) passes so that the end of the rotor portion (110) can be coupled to the power transmission portion (140). Accordingly, the rotor portion (110) can receive rotational driving force from the power transmission portion (140).

[0078] However, since a through hole is formed in the first housing part (131), liquid may leak through the through hole, and in order to prevent such a problem from occurring, the liquid pump unit (100) further includes at least one sealing part (150) that is placed in the internal receiving space of the housing part (130) and surrounds a portion of the outer circumference of the rotor part (110).

[0079] Specifically, the sealing portion (150) is positioned close to the through hole in the internal receiving space of the first housing portion (131) and is formed to surround the outer circumference of the body portion (112) of the rotor portion (110). Accordingly, the sealing portion (150) prevents the liquid in the internal receiving space of the first housing portion (131) from leaking toward the power transmission portion (140) through the through hole.

[0080] Accordingly, the sealing portion (150) may be configured as a mechanical seal equipped with an O-ring (R) to prevent liquid from leaking between the rotating rotor portion (110) and the through hole through which the end of the rotor portion (110) passes. However, the sealing portion (150) may have any structure that is capable of sealing, and is not limited to a mechanical seal structure.

[0081] Meanwhile, the power transmission unit (140) transmits the motor driving force of the driving unit (200) to the rotor unit (110), is fixedly coupled to the housing unit (130), and is detachably coupled to the driving unit (200), thereby enabling the liquid pump unit (100) to be replaced as an integral part of the driving unit (200).

[0082] Specifically, the power transmission unit (140) is arranged between the housing unit (130) and the drive unit (200), and serves to transmit the motor operation of the drive unit (200) to the rotor unit (110). The power transmission unit (140) has a structure that allows the liquid pump unit (100) to be easily attached to and detached from the drive unit (200), while providing the driving force of the drive unit (200) to the rotor unit (110) completely and stably.

[0083] Specifically, the power transmission unit (140) is formed with a first connection unit (140a) to which an end of the rotor unit (110) is connected on one side, and a second connection unit (140b) which is directly or indirectly connected to the motor rotation shaft of the drive unit (200) on the other side. Here, one side of the power transmission unit (140) is a side close to the first housing unit (131), and the other side of the power transmission unit (140) can be understood as a side close to the drive unit (200).

[0084] For example, the first connecting portion (140a) may be formed as a receiving space into which the end of the body portion (111) of the rotor portion (110) is fitted. In addition, the second connecting portion (140b) may be indirectly connected to the motor rotation shaft, and may be formed, for example, in the form of a protrusion fitted to a coupling (C) coupled to the motor rotation shaft.

[0085] Accordingly, the user can stably separate and reattach the entire liquid pump unit (100), including the rotor unit (110), from the drive unit (200) by easily and simply detaching the power transmission unit (140) from the drive unit (200), and can easily replace and discard the liquid pump unit (100) like a consumable, and can completely and stably transmit the driving force of the drive unit (200) to the rotor unit (110) by forming the first connection portion (140a) and the second connection portion (140b).

[0086] Meanwhile, the aforementioned driving unit (200) is coupled to the liquid pump unit (100) to provide driving force, and includes at least one motor. Specifically, referring again to FIGS. 2 and 3, the driving unit (200) includes a motor receiving portion (210) that receives the motor; and a bridge portion (220) that is provided on the upper portion of the motor receiving portion (210) and connects the motor receiving portion (210) and the liquid pump unit (100).

[0087] The above motor housing (210) includes a housing that houses a motor. A power line (E) for power supply is connected to the motor, and a coupling (C) can be coupled to the rotational shaft of the motor. Note that the motor is placed inside the motor housing (210) and is not shown in the drawing.

[0088] Meanwhile, the bridge portion (220) is provided on the upper portion of the motor receiving portion (210) and connects the motor receiving portion (210) and the liquid pump unit (100).

[0089] As shown in FIGS. 2 and 3, the bridge portion (220) has an internal space formed to accommodate at least a portion of the liquid pump unit (100), and has a function of fixing and supporting the coupling (C) coupled to the motor rotation shaft so that the alignment of the coupling (C) is not distorted.

[0090] As an example, on the side of the bridge portion (220), as shown in FIGS. 2 and 3, a first sliding groove (220a) is formed into which a cover unit (300) to be described later can be slidably coupled; and on the lower part of the bridge portion (220), as shown in FIG. 2, a pair of second sliding grooves (220b) are formed into which the motor receiving portion (210) is slidably coupled.

[0091] Accordingly, the liquid discharge device (10) of the present invention can be simply assembled by slidingly connecting the liquid pump unit (100), the cover unit (300), and the motor receiving portion (210) to the bridge portion (220). It goes without saying that the first sliding groove (220a) and the second sliding groove (220b) can be formed in various shapes and numbers.

[0092] Meanwhile, the liquid pump unit (100), cover unit (300), and motor receiving portion (210) can be coupled to the bridge portion (220) in various ways other than the sliding method.

[0093] For example, the bridge portion (220) has a space suitable for the shape of a consumable of the liquid pump unit (100) and a fixing device (e.g., a cover) that opens and closes the space, and the liquid pump unit (100) is completely fixed by closing the space with the fixing device while the liquid pump unit (100) is fitted into the space, or various methods can be used, such as a method of mounting the liquid pump unit (100) to the bridge portion (220) in a cartridge structure.

[0094] In addition, the liquid discharge device (10) of the present invention may further include a safety device that operates the drive unit (200) only when the liquid pump unit (100) is completely mounted and fixed on the bridge portion (220) or the liquid pump unit (100) is completely mounted on the bridge portion (220) and the fixing device closes the space, by separately providing an object detection sensor (e.g., a Hall sensor) on the bridge portion (220), and the object detection sensor detects that the liquid pump unit (100) is completely mounted on the bridge portion (220).

[0095] Meanwhile, the bridge portion (220) of the present invention may be configured to be detachably coupled to the upper portion of the motor receiving portion (210), and may also be formed integrally with the motor receiving portion (210) without being separated therefrom. If the bridge portion (220) is formed integrally with the motor receiving portion (210) without being separated therefrom, there is no need to form a pair of second sliding grooves (220b) in the bridge portion (220) to which the motor receiving portion (210) slides. In this case, the bridge portion (220) may be formed only as a space for accommodating the liquid pump unit (100) in the drive unit (200), and thus it may be understood that the drive unit (200) itself is formed as a single configuration in which a space for accommodating the liquid pump unit (100) and a space for accommodating the motor are respectively formed.

[0096] Meanwhile, the cover unit (300) will be described below.

[0097] The above cover unit (300) is coupled to the upper portion of the liquid pump unit (100) and fixes the liquid pump unit (100) to the drive unit (200).

[0098] Specifically, the cover unit (300) surrounds the upper portion of the liquid pump unit (100) and connects the liquid pump unit (100) to the drive unit (200), thereby fixing the liquid pump unit (100) to a part of the drive unit (200), for example, the bridge portion (220). To this end, as illustrated in FIGS. 2 and 3, one or more fitting portions (300a) having a width corresponding to the width of the first sliding groove (220a) of the bridge portion (200) are protrudingly formed on the cover unit (300).

[0099] This fitting part (300a) is slidably fitted into the first sliding groove (220a), and thus the cover unit (300) and the liquid pump unit (100) can be slidably coupled to the drive unit (200). For example, the cover unit (300) and the liquid pump unit (100) are slidably coupled to the bridge part (220). After the liquid pump unit (100) is received in the bridge part (220), the cover unit (300) is fitted and fixed to the bridge part (220), thereby preventing the liquid pump unit (100) from being separated from the bridge part (220).

[0100] Meanwhile, the graph of Fig. 7 is a graph showing the change in flow rate over time of the liquid discharge device (10) of the present invention. That is, this shows the change in the amount of liquid transported over time when the motor rotation speed of the drive unit (200) that transmits driving force to the rotor unit (110) is changed in order to gradually reduce the set flow rate value.

[0101] Specifically, the graph of FIG. 7 shows that when the set flow rate value of the liquid discharge device (10) of the present invention is divided into sections at time intervals of about 1 minute from about 9 ml / h to 1 ml / h and the motor rotation speed is reduced so that the set flow rate value decreases by 1 ml / h, the flow rate decreases and is discharged as intended as each section passes, and in particular, the flow rate is maintained constant and is discharged within each section.

[0102] That is, through this, it can be confirmed that the liquid discharge device (10) of the present invention has a liquid pump unit (100) including a consumable rotor part (110) and a stator part (120) that are simpler than the structure of a conventional progressive cavity pump device, while exhibiting the same level of flow rate transmission performance as a conventional progressive cavity pump device.

[0103] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that this also falls within the scope of the present invention.

Claims

1. Liquid pump unit; and A drive unit is included that is coupled to the liquid pump unit to provide driving force; The above liquid pump unit, A rotor having a screw shape; A stator section having a female screw shape and accommodating at least a portion of the rotor section; A housing portion surrounding the rotor portion and the stator portion, and having an internal receiving space through which liquid flows; and A power transmission unit that transmits the motor driving force of the above driving unit to the above rotor unit, is fixedly coupled to the housing unit, and is detachably coupled to the driving unit; A liquid discharge device in which the liquid pump unit is detachably coupled to the drive unit so as to be replaceable as an integral part.

2. In paragraph 1, The above power transmission unit, A first connecting portion is formed on one side to which an end of the rotor portion is connected; A liquid discharge device, wherein a second connection part is formed on the other side, which is directly or indirectly connected to the motor rotation shaft of the drive unit.

3. In paragraph 1, The above rotor part, A head portion in the shape of a male screw placed in the hollow portion of the above stator portion; A body part having one end connected to the head part and the other end connected to the power transmission part; and It comprises at least one protrusion formed protruding from the outer surface of the body portion; A liquid discharge device in which at least one groove is formed on the outer surface of the above-mentioned protrusion.

4. In paragraph 3, A liquid discharge device in which the above groove is formed in a spiral shape along the circumference of the above protrusion.

5. In paragraph 3, A liquid discharge device in which the head portion, the body portion, and the protrusion portion are formed of a synthetic resin material and are integrally injection-molded.

6. In paragraph 1, The above housing part, A first housing part coupled to the power transmission part and having a liquid supply part that receives liquid from the outside; and A liquid discharge device comprising a second housing portion that is coupled to the first housing portion and has a liquid discharge portion formed therein for discharging liquid to the outside.

7. In paragraph 1, The above liquid pump unit, A liquid discharge device, which is arranged in an internal receiving space of the housing portion and further includes at least one sealing portion surrounding a portion of the outer circumference of the rotor portion.

8. In paragraph 1, The above drive unit, a motor receiving portion for receiving the above motor; and A liquid discharge device comprising a bridge portion provided on the upper portion of the motor receiving portion and connecting the motor receiving portion and the liquid pump unit.

9. In paragraph 1, A liquid discharge device further comprising a cover unit coupled to the upper portion of the liquid pump unit and fixing the liquid pump unit to the drive unit.

10. In paragraph 9, A liquid discharge device wherein the cover unit and the liquid pump unit are slidably fitted into the drive unit.

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