Water Pump

Abstract

A water pump including an upper casing and a lower casing that are formed with an inlet into which fluid is introduced and an outlet through which the fluid is discharged; and an impeller that is accommodated inside, formed by the coupling of the upper casing and the lower casing. The impeller is formed with a down force generation part that generates a force that pushes the impeller downward by coming into contact with fluid within a flow path through which the fluid passes and the down force generation part is formed such that a height of an ending point (E) is higher than a height of a starting point(S).

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Korean Patent Application No. 10-2024-0128358 filed Sep. 23, 2024, the disclosure of which is hereby incorporated by reference in its entirety.BACKGROUNDTechnical Field

[0002] The following disclosure relates to relates to a water pump capable of pumping coolant by rotating an impeller.Technical Considerations

[0003] A water pump is a device for circulating a coolant to an engine or heater for cooling the engine or heating a room. The water pumps are broadly categorized into a mechanical water pump and an electric water pump.

[0004] The mechanical water pump is a pump that is connected to an engine crankshaft and driven by a rotation of a crankshaft, and the electric water pump is a pump that is driven by a rotation of a motor controlled by a control device.

[0005] FIG. 1 is a front cross-sectional view of a conventional water pump.

[0006] Referring to FIG. 1, the conventional water pump largely includes a housing 10, a stator 20, a can 30, a rotor 40, a rotary shaft 41, a lower bearing 42, an upper bearing 43, an impeller 50, and an upper casing 60.

[0007] More specifically, the stator 20 is provided inside the housing 10 in which a concave accommodation space is formed, a protrusion formed convexly downward of the can 30 is inserted so as to penetrate through a central portion of the stator 20, and an upper portion of the can 30 is coupled to an upper end portion of the housing 10. In addition, a concave space is formed on an inside of a protrusion of the can 30, and the rotor 40 is disposed inside the space, and both end portions of the rotary shaft 41 coupled to the rotor 40 are coupled to and supported by the lower bearing 42 and an upper bearing 43. In addition, the upper casing 60 is coupled to an upper side of the can 30, and the impeller 50 is provided in an internal space formed by the coupling of the can 30 and the upper casing 60, and the impeller 50 is coupled to the rotary shaft 41 so as to be able to rotate together with the rotor 40. Thus, fluid introduced into an inlet pipe 61 formed in the upper casing 60 by the rotation of the impeller 50 may be pressurized through the impeller 50 and then discharged through an outlet pipe 62 formed in the upper casing 60.

[0008] However, when the impeller 50 rotates, a portion of the fluid discharged from the impeller 50 is introduced into a space between a lower surface of the impeller 50 and the can 30, thereby exerting pressure. Furthermore, another portion of the fluid discharged from the impeller 50 flows through a space between an upper surface of the impeller 50 and the upper casing 60 and returns to an inlet side of the impeller 50. In this case, since the fluid pressure between the upper surface of the impeller 50 and the upper casing 60 is lower than the fluid pressure between the lower surface of the impeller 50 and the can 30, an upward thrust for moving the impeller 50 and rotor 40 axially upward is generated.

[0009] The upward thrust reduces the performance and efficiency of the water pump, and increases friction in bearings that axially support a rotary shaft of the rotor, thereby reducing durability. An existing water pump is shown and described in KR 10-2015-0052436 A (May 14, 2015) “Water Pump”.SUMMARY

[0010] A non-limiting embodiment of the present disclosure is directed to providing a water pump capable of improving performance and efficiency by reducing a thrust generated when an impeller rotates.

[0011] In one non-limiting aspect, a water pump includes: an upper casing and a lower casing that are coupled to each other to form an impeller accommodation space in which an impeller is rotatably accommodated, and have an inlet formed above the impeller accommodation space to communicate with the impeller accommodation space and to allow fluid to flow in, a discharge channel formed radially outside the impeller accommodation space to communicate with the impeller accommodation space, and an outlet connected to the discharge channel to discharge the fluid to an outside; and an impeller that is rotatably provided in the impeller accommodation space, in which the impeller is formed with a down force generation part that generates a force that pushes the impeller downward by coming into contact with fluid within a flow path through which the fluid passes, and the down force generation part is formed such that a height of an ending point (E) is higher than a height of a starting point(S).

[0012] The impeller may be a centrifugal impeller, and a fluid discharge angle (θ1) formed by a fluid discharge direction in which the fluid is discharged from the impeller with respect to a fluid inlet direction in which fluid is introduced from the upper casing toward the impeller may be less than 90°.

[0013] The fluid inlet direction, in which the fluid is introduced from the upper casing toward the impeller, may be a direction parallel to a rotational center axis of the impeller.

[0014] The impeller may include an upper plate and a lower plate disposed spaced apart from each other vertically, and a plurality of blades disposed spaced apart from each other along a circumferential direction and coupled to the upper plate and the lower plate, and a through hole may be formed in a radially central portion of the upper plate to allow the fluid to be introduced through both upper and lower surfaces, and the fluid may be discharged from radially outer ends of the plurality of blades.

[0015] The radial outer upper surface of the lower plate may be formed to be curved or bent in an outward and upward direction.

[0016] The down force generation part may include all portions in which the radially outer surfaces of the lower plate, the plurality of blades, and the upper plate are all curved or bent outwardly and upwardly.

[0017] The down force generation part may be formed between a fluid inlet side, which is a radially inner side, and a fluid discharge side, which is a radially outer side, of the impeller.

[0018] The impeller may be formed at a constant height from the ending point of the down force generating part (E) to the radially outer end.

[0019] The upper casing may have an upper flow path groove formed radially on the outer side of the impeller accommodation space and communicating with the impeller accommodation space, the lower casing may have a lower flow path groove formed radially on the outer side of the impeller accommodation space and communicating with the impeller accommodation space, and the upper flow path groove and the lower flow path groove may together form the discharge channel.

[0020] The lower casing may be formed with a rotor accommodation part that has a rotor accommodation space recessed downward from the upper surface at the central portion and protrudes downward, and the water pump may further include: a rotor that is provided in the rotor accommodation part and coupled to an impeller; a motor housing that is coupled to the lower casing; and a stator that is provided inside the motor housing and has the rotor accommodation part of the lower casing inserted into the central portion.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a cross-sectional view of a conventional water pump according to the existing art;

[0022] FIGS. 2 and 3 are an assembled perspective view and a front cross-sectional view illustrating a water pump according to a non-limiting embodiment of the present disclosure;

[0023] FIG. 4 is a partial enlarged view of FIG. 3;

[0024] FIG. 5 is a partial cross-sectional view of a water pump according to another non-limiting embodiment of the present disclosure; and

[0025] FIG. 6 is a cross-sectional view of a modified embodiment of FIG. 5.DETAILED DESCRIPTION

[0026] Hereinafter, a water pump of the present disclosure will be described in detail with reference to the accompanying drawings.

[0027] FIGS. 2 and 3 are an assembled perspective view and a front cross-sectional view illustrating a water pump according to a non-limiting embodiment of the present disclosure, FIG. 4 is a partial enlarged view of FIG. 3, and FIG. 5 is a partial cross-sectional view of a water pump according to a non-limiting embodiment of the present disclosure.

[0028] As illustrated, the water pump according to a non-limiting embodiment of the present disclosure may include an upper casing 600, a lower casing 200, and an impeller 500. In addition, the water pump according to a non-limiting embodiment of the present disclosure may further include a rotor 400, a motor housing 300, and a stator 100.

[0029] The upper casing 600 may have an upper seating groove 630 formed concavely upward from a lower surface to allow a portion of the impeller 500 to be inserted therein. In addition, an upper flow path groove 632 may be formed concavely on the lower surface of the upper casing 600 radially outside the upper seating groove 630. Here, the upper seating groove 630 and the upper flow path groove 632 may be formed adjacent to each other but spaced apart from each other. The upper seating groove 630 and the upper flow path groove 632 communicate with each other radially, but a partial region in a vertical direction may be partitioned by an upper baffle 631 at a position therebetween. In addition, the upper casing 600 may have an inlet 610 into which fluid is introduced. For example, an outlet 620, through which fluid is discharged, may be formed in the upper casing 600. In addition, the upper casing 600 may have the inlet 610 disposed at the upper central portion, the inlet 610 may communicate with the impeller accommodation space, and the outlet 620 may be connected to and communicate with a downstream end of the upper flow path groove 632 in a flow direction of fluid.

[0030] The lower casing 200 is coupled to a lower side of the upper casing 600, and an impeller accommodation space, in which an impeller 500 may be accommodated, may be formed between the upper casing 600 and the lower casing 200 by the coupling of the upper casing 600 and the lower casing 200. The lower casing 200 may have a lower seating groove 210 formed concavely downward from the upper surface so that a lower side of the impeller 500 may be partially inserted. In addition, the lower casing 200 may have a lower flow path groove 212 formed concavely corresponding to an upper flow path groove 623, so the upper flow path groove 632 and the lower flow path groove 212 may form a discharge channel. Thus, the fluid discharged from the impeller 500 may flow along the discharge channel. In addition, the lower seating groove 210 and the lower flow path groove 212 may be formed adjacent to each other but spaced apart from each other, and the lower seating groove 210 and the lower flow path groove 212 communicate with each other radially, but the partial region in the vertical direction may be partitioned by the lower baffle 211 at a position therebetween.

[0031] The impeller 500 is provided in the impeller accommodation space, which is an internal space formed by the coupling of the upper casing 600 and the lower casing 200, and the impeller 500 is connected to the rotor 400 so that the impeller 500 may rotate together with the driving of the rotor 400. For example, the impeller 500 may be a centrifugal impeller. The impeller 500 may include an upper plate 510, a lower plate 520, and a plurality of blades 530, and the plurality of blades 530 may be formed to be spaced circumferentially from each other between the upper plate 510 and the lower plate 520 disposed spaced apart vertically from each other. A central portion of the upper plate 510 is formed with a through hole 511 penetrating vertically through both surfaces, so that fluid may be introduced into the interior of the impeller 500 through the through hole 511. In addition, the fluid introduced into the impeller 500 flows from the radial inside to the outside along a path partitioned by the plurality of blades 530 in the upper plate 510 and the lower plate 520, and the fluid may be discharged from the outer end of the impeller 500 in the radial direction. In addition, the outer end of the impeller 500 is disposed adjacent to the upper flow path groove 632 and the lower flow path groove 212 forming the discharge channel, an outer circumferential surface of the upper plate 510 and the upper baffle 631 are spaced apart from each other with a specific gap in the radial direction, and an outer circumferential surface of the lower plate 530 and the lower baffle 211 are spaced apart from each other with a specific gap in the radial direction. In addition, blade tips of the plurality of blades 530 may be formed to coincide with the outer circumferential surfaces of the upper plate 510 and the lower plate 530. In addition, as an example, the impeller 500 may be formed in a form in which the plurality of blades 530 and the lower plate 520 are formed integrally with the rotor 400, and the upper plate 510 is coupled to the upper side of the blades 530. In addition, the impeller may be formed in various shapes. In addition, there is a gap between the upper surface of the upper plate 510 of the impeller 500 and the upper seating groove 630, and there is also a gap between a lower surface of the lower plate 520 of the impeller 500 and the lower seating groove 210. The radial direction may be a radial direction of the impeller 500, and the axial direction may be a direction of the rotary shaft 410 which is a central shaft of the impeller 500. In addition, the impeller 500 is formed with a down force generation part 540 that generates a force that pushes the impeller downward by coming into contact with fluid within a flow path through which the fluid passes, and the down force generation part 540 may be formed so that the height of the ending point E is higher than the height of the starting point S.

[0032] Thus, the fluid introduced into the inlet 610 of the upper casing 600 may be introduced into the inside of the impeller 500 through the through hole 511 formed in the upper plate 510 of the impeller 500. Thereafter, the fluid pressurized by the centrifugal force resulting from the rotation of the impeller 500 may be discharged from the outer end of the impeller 500 and flow along the discharge channel formed by the upper flow path groove 632 and the lower flow path groove 212, and then discharged to the outside through the outlet 620.

[0033] Here, when the impeller rotates, an upward thrust is generated that causes the impeller 500 and the rotor 400 to move upward in the direction of the central axis due to the pressure of the fluid. In addition, the fluid discharged from the outer end of the impeller 500 may flow along the discharge channel as it rotates. The down force, which is a force that pushes the impeller 500 downward due to the reaction force of the fluid being discharged from the outer end of the impeller 500, may be generated. Accordingly, the upward thrust and the downward down force cancel each other out, thereby reducing the overall thrust generated by the impeller and the rotor. As a result, the performance and efficiency of the water pump are improved, and the friction between the rotary shaft of the rotor and the bearing that supports it in the axial direction is reduced, thereby improving the durability of the water pump.

[0034] In addition, the impeller 500 may be formed so that the fluid discharge angle θ1 formed by the fluid discharge direction 550 in which the fluid is discharged from the impeller 500 with respect to the fluid inlet direction 640 in which the fluid flows into the impeller is less than 90°. That is, the fluid discharge angle θ1 may be formed as an acute angle. The fluid inlet direction 640 in which the fluid is introduced from the upper casing 600 toward the impeller 500 may be a direction in which the fluid flowing along the inlet 610 of the upper casing 600 flows toward the through hole 511 formed in the central portion of the upper plate 510 of the impeller 500. In addition, the fluid inlet direction 640 may be a direction parallel to the rotational center axis of the impeller 500, that is, the rotary shaft 410 of the rotor 400. Therefore, the down force, which is a force that pushes the impeller downward, may be easily generated by the reaction force of the fluid being discharged from the impeller.

[0035] In addition, the down force generation part that is curved or bent in a radially outward upward direction may be formed on the radially outer upper surface of the lower plate 530 of the impeller 500. That is, the down force generation part 540 may be curved or bent in a radially outward upward direction with respect to the radial direction of the impeller 500 perpendicular to the rotational center axis of the impeller 500. Alternatively, the down force generation part 540 may include all portions of the lower plate 530, the plurality of blades 520, and the upper plate 510 of the impeller 500 that are all curved or bent in the radially outward upward direction. Thus, since the fluid passing between the upper plate 510 and the lower plate 520 generates the down force that pushes the impeller 500 downward while hitting the upper surface of the radially outer end of the lower plate 520 and is then discharged from the outer end of the impeller 500, the down force may be generated more easily.

[0036] FIG. 6 is a cross-sectional view of a modified non-limiting embodiment of FIG. 5.

[0037] As illustrated, the down force generation part 540 according to the present disclosure may be formed in the middle of the path along which the fluid passes through the inside of the impeller 500. That is, the down force generation part 540 may be formed at a position between the fluid inlet side, which is a radially inner side, and the fluid discharge side, which is a radially outer side, of the impeller 500. The starting point of the down force generation part S may be formed at a position spaced outwardly from the inner end, which is the fluid inlet side, in the radial direction, and the ending point of the down force generation part E may be formed at a position spaced inwardly from the outer end, which is the fluid discharge side, in the radial direction. In addition, impeller 500 may be formed at a constant height from the ending point of the down force generation part E to the radially outer end. That is, the ending point E of the down force generation part to the outer end in the radial direction may be formed at a 90° direction with respect to the fluid inlet direction 640.

[0038] In addition, the upper casing 600 may be formed with multiple supports extending from a portion near the lower end of the inlet 610 toward the impeller accommodation space, and an upper bearing mounting part 602 may be formed at the ends of the multiple supports. An upper bearing 412, including a bushing B and a thrust pin P, may be coupled to the upper bearing mounting part 602. In addition, the upper bearing mounting part 602 and the support 612 may be formed integrally with the upper casing 600 by injection molding.

[0039] In addition, the lower casing 200 may have a rotor accommodation part 220 protruding downward from the central portion of the lower seating groove 210, and the rotor accommodation part 220 may be formed in a downwardly concave container shape on the upper side. In addition, the rotor accommodation part 220 may have a lower bearing mounting part 222 formed at a lower end of the rotor accommodation space which is a concave inside, so the lower bearing 411 may be coupled to the lower bearing mounting part 222. Here, the lower bearing 411 including a bushing B and a spherical ball S may be coupled to the lower bearing mounting part 222. Accordingly, the rotor 400 is inserted into and disposed in the rotor accommodation space that is the inside of the rotor accommodation part 220, and the outer circumferential surface of the rotor 400 may be disposed spaced apart from the inner circumferential surface of the rotor accommodation part 220. In addition, the rotor accommodation part 220 may be formed integrally with the lower casing 200 by injection molding. In addition, the rotor accommodation part 220 of the lower casing 200 may be inserted into the hollow inner side of the stator 100, and the outer circumference of the rotor accommodation part 220 may be in contact with and coupled to the inner circumferential surface of the stator 100.

[0040] The motor housing 300 may be coupled to the lower casing 200. For example, the motor housing 300 may be formed in a concave container, and may be formed in the form in which the inside is empty and the upper side is open. The motor housing 300 may be formed in the form in which a lower end is closed and a side surface is formed in a cylindrical shape, and formed with a flange protruding radially outward from the outer peripheral surface at the upper end.

[0041] For example, the stator 100 may have a plurality of teeth protruding radially inward from an inner circumferential surface of a cylindrical core, the teeth are disposed circumferentially spaced apart from each other, and an insulator made of an electrically insulating material surrounds the core and the teeth, with coils wound around the outside of the teeth surrounded by the insulator. In addition, the central portion may be open vertically. In addition, the stator 100 may be formed in various shapes and configurations. In addition, the stator 100 may be provided inside the motor housing 300 and may be fixedly coupled to the motor housing 300 in a state where an outer peripheral surface of the stator 100 is in contact with the inner peripheral surface of the motor housing 300.

[0042] The rotor 400 is provided in the rotor accommodation space of the lower casing 200, and the outer circumferential surface of the rotor 400 may be disposed to be rotatably spaced apart from the inner circumferential surface of the rotor accommodation part 220. In addition, the rotor 400 has a permanent magnet coupled to a radially outer portion of the core, and the rotary shaft 410 coupled to the central axis of the core. In addition, the lower end of the rotary shaft 410 of the rotor 400 may be rotatably coupled to the lower bearing 411, and the upper end thereof may be rotatably coupled to the upper bearing 412. In addition, the upper bearing mounting part 602 may be partially or entirely disposed inside the inlet side of the impeller 500. For example, an insertion groove is formed concavely downward in the central portion of the lower plate 520, which is the lower end of the inlet side of the impeller 500, and in the upper end of the rotor 400, the upper bearing mounting part 602 is inserted into the insertion groove, and the insertion groove and the upper bearing mounting part 602 may be disposed to be spaced apart from each other.

[0043] According to the present disclosure, it is possible to improve the performance and efficiency of the water pump by reducing the thrust generated during the rotation of the impeller.

[0044] In addition, the reduced thrust reduces the friction between the rotary shaft of the rotor and the bearing axially supporting the rotary shaft of the rotor, thereby improving the durability of the water pump.

[0045] The present disclosure is not limited to the above-described exemplary embodiments, but may be variously applied. In addition, the present disclosure may be variously modified by those skilled in the art to which the present disclosure pertains without departing from the gist of the present disclosure claimed in the claims.

Examples

Embodiment Construction

[0026]Hereinafter, a water pump of the present disclosure will be described in detail with reference to the accompanying drawings.

[0027]FIGS. 2 and 3 are an assembled perspective view and a front cross-sectional view illustrating a water pump according to a non-limiting embodiment of the present disclosure, FIG. 4 is a partial enlarged view of FIG. 3, and FIG. 5 is a partial cross-sectional view of a water pump according to a non-limiting embodiment of the present disclosure.

[0028]As illustrated, the water pump according to a non-limiting embodiment of the present disclosure may include an upper casing 600, a lower casing 200, and an impeller 500. In addition, the water pump according to a non-limiting embodiment of the present disclosure may further include a rotor 400, a motor housing 300, and a stator 100.

[0029]The upper casing 600 may have an upper seating groove 630 formed concavely upward from a lower surface to allow a portion of the impeller 500 to be inserted therein. In ad...

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Korean Patent Application No. 10-2024-0128358 filed Sep. 23, 2024, the disclosure of which is hereby incorporated by reference in its entirety.BACKGROUNDTechnical Field

[0002] The following disclosure relates to relates to a water pump capable of pumping coolant by rotating an impeller.Technical Considerations

[0003] A water pump is a device for circulating a coolant to an engine or heater for cooling the engine or heating a room. The water pumps are broadly categorized into a mechanical water pump and an electric water pump.

[0004] The mechanical water pump is a pump that is connected to an engine crankshaft and driven by a rotation of a crankshaft, and the electric water pump is a pump that is driven by a rotation of a motor controlled by a control device.

[0005] FIG. 1 is a front cross-sectional view of a conventional water pump.

[0006] Referring to FIG. 1, the conventional water pump largely includes a housing 10, a stator 20, a can 30, a rotor 40, a rotary shaft 41, a lower bearing 42, an upper bearing 43, an impeller 50, and an upper casing 60.

[0007] More specifically, the stator 20 is provided inside the housing 10 in which a concave accommodation space is formed, a protrusion formed convexly downward of the can 30 is inserted so as to penetrate through a central portion of the stator 20, and an upper portion of the can 30 is coupled to an upper end portion of the housing 10. In addition, a concave space is formed on an inside of a protrusion of the can 30, and the rotor 40 is disposed inside the space, and both end portions of the rotary shaft 41 coupled to the rotor 40 are coupled to and supported by the lower bearing 42 and an upper bearing 43. In addition, the upper casing 60 is coupled to an upper side of the can 30, and the impeller 50 is provided in an internal space formed by the coupling of the can 30 and the upper casing 60, and the impeller 50 is coupled to the rotary shaft 41 so as to be able to rotate together with the rotor 40. Thus, fluid introduced into an inlet pipe 61 formed in the upper casing 60 by the rotation of the impeller 50 may be pressurized through the impeller 50 and then discharged through an outlet pipe 62 formed in the upper casing 60.

[0008] However, when the impeller 50 rotates, a portion of the fluid discharged from the impeller 50 is introduced into a space between a lower surface of the impeller 50 and the can 30, thereby exerting pressure. Furthermore, another portion of the fluid discharged from the impeller 50 flows through a space between an upper surface of the impeller 50 and the upper casing 60 and returns to an inlet side of the impeller 50. In this case, since the fluid pressure between the upper surface of the impeller 50 and the upper casing 60 is lower than the fluid pressure between the lower surface of the impeller 50 and the can 30, an upward thrust for moving the impeller 50 and rotor 40 axially upward is generated.

[0009] The upward thrust reduces the performance and efficiency of the water pump, and increases friction in bearings that axially support a rotary shaft of the rotor, thereby reducing durability. An existing water pump is shown and described in KR 10-2015-0052436 A (May 14, 2015) “Water Pump”.SUMMARY

[0010] A non-limiting embodiment of the present disclosure is directed to providing a water pump capable of improving performance and efficiency by reducing a thrust generated when an impeller rotates.

[0011] In one non-limiting aspect, a water pump includes: an upper casing and a lower casing that are coupled to each other to form an impeller accommodation space in which an impeller is rotatably accommodated, and have an inlet formed above the impeller accommodation space to communicate with the impeller accommodation space and to allow fluid to flow in, a discharge channel formed radially outside the impeller accommodation space to communicate with the impeller accommodation space, and an outlet connected to the discharge channel to discharge the fluid to an outside; and an impeller that is rotatably provided in the impeller accommodation space, in which the impeller is formed with a down force generation part that generates a force that pushes the impeller downward by coming into contact with fluid within a flow path through which the fluid passes, and the down force generation part is formed such that a height of an ending point (E) is higher than a height of a starting point(S).

[0012] The impeller may be a centrifugal impeller, and a fluid discharge angle (θ1) formed by a fluid discharge direction in which the fluid is discharged from the impeller with respect to a fluid inlet direction in which fluid is introduced from the upper casing toward the impeller may be less than 90°.

[0013] The fluid inlet direction, in which the fluid is introduced from the upper casing toward the impeller, may be a direction parallel to a rotational center axis of the impeller.

[0014] The impeller may include an upper plate and a lower plate disposed spaced apart from each other vertically, and a plurality of blades disposed spaced apart from each other along a circumferential direction and coupled to the upper plate and the lower plate, and a through hole may be formed in a radially central portion of the upper plate to allow the fluid to be introduced through both upper and lower surfaces, and the fluid may be discharged from radially outer ends of the plurality of blades.

[0015] The radial outer upper surface of the lower plate may be formed to be curved or bent in an outward and upward direction.

[0016] The down force generation part may include all portions in which the radially outer surfaces of the lower plate, the plurality of blades, and the upper plate are all curved or bent outwardly and upwardly.

[0017] The down force generation part may be formed between a fluid inlet side, which is a radially inner side, and a fluid discharge side, which is a radially outer side, of the impeller.

[0018] The impeller may be formed at a constant height from the ending point of the down force generating part (E) to the radially outer end.

[0019] The upper casing may have an upper flow path groove formed radially on the outer side of the impeller accommodation space and communicating with the impeller accommodation space, the lower casing may have a lower flow path groove formed radially on the outer side of the impeller accommodation space and communicating with the impeller accommodation space, and the upper flow path groove and the lower flow path groove may together form the discharge channel.

[0020] The lower casing may be formed with a rotor accommodation part that has a rotor accommodation space recessed downward from the upper surface at the central portion and protrudes downward, and the water pump may further include: a rotor that is provided in the rotor accommodation part and coupled to an impeller; a motor housing that is coupled to the lower casing; and a stator that is provided inside the motor housing and has the rotor accommodation part of the lower casing inserted into the central portion.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a cross-sectional view of a conventional water pump according to the existing art;

[0022] FIGS. 2 and 3 are an assembled perspective view and a front cross-sectional view illustrating a water pump according to a non-limiting embodiment of the present disclosure;

[0023] FIG. 4 is a partial enlarged view of FIG. 3;

[0024] FIG. 5 is a partial cross-sectional view of a water pump according to another non-limiting embodiment of the present disclosure; and

[0025] FIG. 6 is a cross-sectional view of a modified embodiment of FIG. 5.DETAILED DESCRIPTION

[0026] Hereinafter, a water pump of the present disclosure will be described in detail with reference to the accompanying drawings.

[0027] FIGS. 2 and 3 are an assembled perspective view and a front cross-sectional view illustrating a water pump according to a non-limiting embodiment of the present disclosure, FIG. 4 is a partial enlarged view of FIG. 3, and FIG. 5 is a partial cross-sectional view of a water pump according to a non-limiting embodiment of the present disclosure.

[0028] As illustrated, the water pump according to a non-limiting embodiment of the present disclosure may include an upper casing 600, a lower casing 200, and an impeller 500. In addition, the water pump according to a non-limiting embodiment of the present disclosure may further include a rotor 400, a motor housing 300, and a stator 100.

[0029] The upper casing 600 may have an upper seating groove 630 formed concavely upward from a lower surface to allow a portion of the impeller 500 to be inserted therein. In addition, an upper flow path groove 632 may be formed concavely on the lower surface of the upper casing 600 radially outside the upper seating groove 630. Here, the upper seating groove 630 and the upper flow path groove 632 may be formed adjacent to each other but spaced apart from each other. The upper seating groove 630 and the upper flow path groove 632 communicate with each other radially, but a partial region in a vertical direction may be partitioned by an upper baffle 631 at a position therebetween. In addition, the upper casing 600 may have an inlet 610 into which fluid is introduced. For example, an outlet 620, through which fluid is discharged, may be formed in the upper casing 600. In addition, the upper casing 600 may have the inlet 610 disposed at the upper central portion, the inlet 610 may communicate with the impeller accommodation space, and the outlet 620 may be connected to and communicate with a downstream end of the upper flow path groove 632 in a flow direction of fluid.

[0030] The lower casing 200 is coupled to a lower side of the upper casing 600, and an impeller accommodation space, in which an impeller 500 may be accommodated, may be formed between the upper casing 600 and the lower casing 200 by the coupling of the upper casing 600 and the lower casing 200. The lower casing 200 may have a lower seating groove 210 formed concavely downward from the upper surface so that a lower side of the impeller 500 may be partially inserted. In addition, the lower casing 200 may have a lower flow path groove 212 formed concavely corresponding to an upper flow path groove 623, so the upper flow path groove 632 and the lower flow path groove 212 may form a discharge channel. Thus, the fluid discharged from the impeller 500 may flow along the discharge channel. In addition, the lower seating groove 210 and the lower flow path groove 212 may be formed adjacent to each other but spaced apart from each other, and the lower seating groove 210 and the lower flow path groove 212 communicate with each other radially, but the partial region in the vertical direction may be partitioned by the lower baffle 211 at a position therebetween.

[0031] The impeller 500 is provided in the impeller accommodation space, which is an internal space formed by the coupling of the upper casing 600 and the lower casing 200, and the impeller 500 is connected to the rotor 400 so that the impeller 500 may rotate together with the driving of the rotor 400. For example, the impeller 500 may be a centrifugal impeller. The impeller 500 may include an upper plate 510, a lower plate 520, and a plurality of blades 530, and the plurality of blades 530 may be formed to be spaced circumferentially from each other between the upper plate 510 and the lower plate 520 disposed spaced apart vertically from each other. A central portion of the upper plate 510 is formed with a through hole 511 penetrating vertically through both surfaces, so that fluid may be introduced into the interior of the impeller 500 through the through hole 511. In addition, the fluid introduced into the impeller 500 flows from the radial inside to the outside along a path partitioned by the plurality of blades 530 in the upper plate 510 and the lower plate 520, and the fluid may be discharged from the outer end of the impeller 500 in the radial direction. In addition, the outer end of the impeller 500 is disposed adjacent to the upper flow path groove 632 and the lower flow path groove 212 forming the discharge channel, an outer circumferential surface of the upper plate 510 and the upper baffle 631 are spaced apart from each other with a specific gap in the radial direction, and an outer circumferential surface of the lower plate 530 and the lower baffle 211 are spaced apart from each other with a specific gap in the radial direction. In addition, blade tips of the plurality of blades 530 may be formed to coincide with the outer circumferential surfaces of the upper plate 510 and the lower plate 530. In addition, as an example, the impeller 500 may be formed in a form in which the plurality of blades 530 and the lower plate 520 are formed integrally with the rotor 400, and the upper plate 510 is coupled to the upper side of the blades 530. In addition, the impeller may be formed in various shapes. In addition, there is a gap between the upper surface of the upper plate 510 of the impeller 500 and the upper seating groove 630, and there is also a gap between a lower surface of the lower plate 520 of the impeller 500 and the lower seating groove 210. The radial direction may be a radial direction of the impeller 500, and the axial direction may be a direction of the rotary shaft 410 which is a central shaft of the impeller 500. In addition, the impeller 500 is formed with a down force generation part 540 that generates a force that pushes the impeller downward by coming into contact with fluid within a flow path through which the fluid passes, and the down force generation part 540 may be formed so that the height of the ending point E is higher than the height of the starting point S.

[0032] Thus, the fluid introduced into the inlet 610 of the upper casing 600 may be introduced into the inside of the impeller 500 through the through hole 511 formed in the upper plate 510 of the impeller 500. Thereafter, the fluid pressurized by the centrifugal force resulting from the rotation of the impeller 500 may be discharged from the outer end of the impeller 500 and flow along the discharge channel formed by the upper flow path groove 632 and the lower flow path groove 212, and then discharged to the outside through the outlet 620.

[0033] Here, when the impeller rotates, an upward thrust is generated that causes the impeller 500 and the rotor 400 to move upward in the direction of the central axis due to the pressure of the fluid. In addition, the fluid discharged from the outer end of the impeller 500 may flow along the discharge channel as it rotates. The down force, which is a force that pushes the impeller 500 downward due to the reaction force of the fluid being discharged from the outer end of the impeller 500, may be generated. Accordingly, the upward thrust and the downward down force cancel each other out, thereby reducing the overall thrust generated by the impeller and the rotor. As a result, the performance and efficiency of the water pump are improved, and the friction between the rotary shaft of the rotor and the bearing that supports it in the axial direction is reduced, thereby improving the durability of the water pump.

[0034] In addition, the impeller 500 may be formed so that the fluid discharge angle θ1 formed by the fluid discharge direction 550 in which the fluid is discharged from the impeller 500 with respect to the fluid inlet direction 640 in which the fluid flows into the impeller is less than 90°. That is, the fluid discharge angle θ1 may be formed as an acute angle. The fluid inlet direction 640 in which the fluid is introduced from the upper casing 600 toward the impeller 500 may be a direction in which the fluid flowing along the inlet 610 of the upper casing 600 flows toward the through hole 511 formed in the central portion of the upper plate 510 of the impeller 500. In addition, the fluid inlet direction 640 may be a direction parallel to the rotational center axis of the impeller 500, that is, the rotary shaft 410 of the rotor 400. Therefore, the down force, which is a force that pushes the impeller downward, may be easily generated by the reaction force of the fluid being discharged from the impeller.

[0035] In addition, the down force generation part that is curved or bent in a radially outward upward direction may be formed on the radially outer upper surface of the lower plate 530 of the impeller 500. That is, the down force generation part 540 may be curved or bent in a radially outward upward direction with respect to the radial direction of the impeller 500 perpendicular to the rotational center axis of the impeller 500. Alternatively, the down force generation part 540 may include all portions of the lower plate 530, the plurality of blades 520, and the upper plate 510 of the impeller 500 that are all curved or bent in the radially outward upward direction. Thus, since the fluid passing between the upper plate 510 and the lower plate 520 generates the down force that pushes the impeller 500 downward while hitting the upper surface of the radially outer end of the lower plate 520 and is then discharged from the outer end of the impeller 500, the down force may be generated more easily.

[0036] FIG. 6 is a cross-sectional view of a modified non-limiting embodiment of FIG. 5.

[0037] As illustrated, the down force generation part 540 according to the present disclosure may be formed in the middle of the path along which the fluid passes through the inside of the impeller 500. That is, the down force generation part 540 may be formed at a position between the fluid inlet side, which is a radially inner side, and the fluid discharge side, which is a radially outer side, of the impeller 500. The starting point of the down force generation part S may be formed at a position spaced outwardly from the inner end, which is the fluid inlet side, in the radial direction, and the ending point of the down force generation part E may be formed at a position spaced inwardly from the outer end, which is the fluid discharge side, in the radial direction. In addition, impeller 500 may be formed at a constant height from the ending point of the down force generation part E to the radially outer end. That is, the ending point E of the down force generation part to the outer end in the radial direction may be formed at a 90° direction with respect to the fluid inlet direction 640.

[0038] In addition, the upper casing 600 may be formed with multiple supports extending from a portion near the lower end of the inlet 610 toward the impeller accommodation space, and an upper bearing mounting part 602 may be formed at the ends of the multiple supports. An upper bearing 412, including a bushing B and a thrust pin P, may be coupled to the upper bearing mounting part 602. In addition, the upper bearing mounting part 602 and the support 612 may be formed integrally with the upper casing 600 by injection molding.

[0039] In addition, the lower casing 200 may have a rotor accommodation part 220 protruding downward from the central portion of the lower seating groove 210, and the rotor accommodation part 220 may be formed in a downwardly concave container shape on the upper side. In addition, the rotor accommodation part 220 may have a lower bearing mounting part 222 formed at a lower end of the rotor accommodation space which is a concave inside, so the lower bearing 411 may be coupled to the lower bearing mounting part 222. Here, the lower bearing 411 including a bushing B and a spherical ball S may be coupled to the lower bearing mounting part 222. Accordingly, the rotor 400 is inserted into and disposed in the rotor accommodation space that is the inside of the rotor accommodation part 220, and the outer circumferential surface of the rotor 400 may be disposed spaced apart from the inner circumferential surface of the rotor accommodation part 220. In addition, the rotor accommodation part 220 may be formed integrally with the lower casing 200 by injection molding. In addition, the rotor accommodation part 220 of the lower casing 200 may be inserted into the hollow inner side of the stator 100, and the outer circumference of the rotor accommodation part 220 may be in contact with and coupled to the inner circumferential surface of the stator 100.

[0040] The motor housing 300 may be coupled to the lower casing 200. For example, the motor housing 300 may be formed in a concave container, and may be formed in the form in which the inside is empty and the upper side is open. The motor housing 300 may be formed in the form in which a lower end is closed and a side surface is formed in a cylindrical shape, and formed with a flange protruding radially outward from the outer peripheral surface at the upper end.

[0041] For example, the stator 100 may have a plurality of teeth protruding radially inward from an inner circumferential surface of a cylindrical core, the teeth are disposed circumferentially spaced apart from each other, and an insulator made of an electrically insulating material surrounds the core and the teeth, with coils wound around the outside of the teeth surrounded by the insulator. In addition, the central portion may be open vertically. In addition, the stator 100 may be formed in various shapes and configurations. In addition, the stator 100 may be provided inside the motor housing 300 and may be fixedly coupled to the motor housing 300 in a state where an outer peripheral surface of the stator 100 is in contact with the inner peripheral surface of the motor housing 300.

[0042] The rotor 400 is provided in the rotor accommodation space of the lower casing 200, and the outer circumferential surface of the rotor 400 may be disposed to be rotatably spaced apart from the inner circumferential surface of the rotor accommodation part 220. In addition, the rotor 400 has a permanent magnet coupled to a radially outer portion of the core, and the rotary shaft 410 coupled to the central axis of the core. In addition, the lower end of the rotary shaft 410 of the rotor 400 may be rotatably coupled to the lower bearing 411, and the upper end thereof may be rotatably coupled to the upper bearing 412. In addition, the upper bearing mounting part 602 may be partially or entirely disposed inside the inlet side of the impeller 500. For example, an insertion groove is formed concavely downward in the central portion of the lower plate 520, which is the lower end of the inlet side of the impeller 500, and in the upper end of the rotor 400, the upper bearing mounting part 602 is inserted into the insertion groove, and the insertion groove and the upper bearing mounting part 602 may be disposed to be spaced apart from each other.

[0043] According to the present disclosure, it is possible to improve the performance and efficiency of the water pump by reducing the thrust generated during the rotation of the impeller.

[0044] In addition, the reduced thrust reduces the friction between the rotary shaft of the rotor and the bearing axially supporting the rotary shaft of the rotor, thereby improving the durability of the water pump.

[0045] The present disclosure is not limited to the above-described exemplary embodiments, but may be variously applied. In addition, the present disclosure may be variously modified by those skilled in the art to which the present disclosure pertains without departing from the gist of the present disclosure claimed in the claims.

Examples

Embodiment Construction

[0026]Hereinafter, a water pump of the present disclosure will be described in detail with reference to the accompanying drawings.

[0027]FIGS. 2 and 3 are an assembled perspective view and a front cross-sectional view illustrating a water pump according to a non-limiting embodiment of the present disclosure, FIG. 4 is a partial enlarged view of FIG. 3, and FIG. 5 is a partial cross-sectional view of a water pump according to a non-limiting embodiment of the present disclosure.

[0028]As illustrated, the water pump according to a non-limiting embodiment of the present disclosure may include an upper casing 600, a lower casing 200, and an impeller 500. In addition, the water pump according to a non-limiting embodiment of the present disclosure may further include a rotor 400, a motor housing 300, and a stator 100.

[0029]The upper casing 600 may have an upper seating groove 630 formed concavely upward from a lower surface to allow a portion of the impeller 500 to be inserted therein. In ad...

Claims

1. A water pump, comprising:an upper casing and a lower casing that are coupled to each other to form an impeller accommodation space in which an impeller is rotatably accommodated, and have an inlet formed above the impeller accommodation space to communicate with the impeller accommodation space and to allow fluid to flow in, a discharge channel formed radially outside the impeller accommodation space to communicate with the impeller accommodation space, and an outlet connected to the discharge channel to discharge the fluid to an outside; andan impeller that is rotatably provided in the impeller accommodation space,wherein the impeller is formed with a down force generation part that generates a force that pushes the impeller downward by coming into contact with fluid within a flow path through which the fluid passes, andthe down force generation part is formed such that a height of an ending point (E) is higher than a height of a starting point(S).

2. The water pump of claim 1, wherein the impeller is a centrifugal impeller, anda fluid discharge angle (θ1) formed by a fluid discharge direction in which the fluid is discharged from the impeller with respect to a fluid inlet direction in which fluid is introduced from the upper casing toward the impeller is less than 90°.

3. The water pump of claim 1, wherein the fluid inlet direction, in which the fluid is introduced from the upper casing toward the impeller, is a direction parallel to a rotational center axis of the impeller.

4. The water pump of claim 1, wherein the impeller comprises an upper plate and a lower plate disposed spaced apart from each other vertically, and a plurality of blades disposed spaced apart from each other along a circumferential direction and coupled to the upper plate and the lower plate, anda through hole is formed in a radially central portion of the upper plate to allow the fluid to be introduced through both upper and lower surfaces, and the fluid is discharged from radially outer ends of the plurality of blades.

5. The water pump of claim 4, wherein the down force generation part is formed in a form in which an upper surface of the lower plate is curved or bent outwardly and upwardly.

6. The water pump of claim 4, wherein the down force generation part comprises all portions in which the radially outer surfaces of the lower plate, the plurality of blades, and the upper plate are all curved or bent outwardly and upwardly.

7. The water pump of claim 4, wherein the down force generation part is formed between a fluid inlet side, which is a radially inner side, and a fluid discharge side, which is a radially outer side, of the impeller.

8. The water pump of claim 7, wherein the impeller is formed at a constant height from the ending point of the down force generating part (E) to the radially outer end.

9. The water pump of claim 1, wherein the upper casing has an upper flow path groove formed radially on the outer side of the impeller accommodation space and communicating with the impeller accommodation space,the lower casing has a lower flow path groove formed radially on the outer side of the impeller accommodation space and communicating with the impeller accommodation space, andthe upper flow path groove and the lower flow path groove together form the discharge channel.

10. The water pump of claim 1, wherein the lower casing is formed with a rotor accommodation part that has a rotor accommodation space recessed downward from the upper surface at the central portion and protrudes downward, and the water pump further comprises: a rotor that is provided in the rotor accommodation part and coupled to an impeller;a motor housing that is coupled to the lower casing; anda stator that is provided inside the motor housing and has the rotor accommodation part of the lower casing inserted into the central portion.

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