US20230160394A1 - Impeller for water pump - Google Patents

Abstract

Provided is an impeller for a water pump which may reduce noise occurring when the impeller is rotated by using a simple configuration, the impeller including: a main plate; and a plurality of blades arranged on one surface of the main plate, and spaced apart from each other in a circumferential direction of the main plate, wherein the plurality of blades are non-equal interval types in which the blades are spaced apart from each other at intervals not equal to each other.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• The present application claims priority to Korean Patent Application No. 10-2021-0160004 filed on Nov. 19, 2021, and to Korean Patent Application No. 10-2022-0113544 filed on Sep. 7, 2022. The entire contents of the above-listed application are hereby incorporated by reference for all purposes.
TECHNICAL FIELD
• The following disclosure relates to an impeller for a water pump that is coupled to a driven rotating shaft and pumping a fluid by a rotational force.
BACKGROUND
• A water pump is a device for circulating cooling water to an engine or a heater for engine cooling or interior heating. This water pump may be roughly classified into a mechanical water pump and an electric water pump.
• The mechanical water pump is a pump connected to a crankshaft of the engine and driven by rotation of the crankshaft, and the electric water pump is a pump driven by rotation of a motor controlled by a control device.
• The electric water pump may roughly include a motor part including a housing, a stator and a rotor, and a pump part including an impeller and an impeller casing. In addition, the stator may be positioned in and fixed to the housing, the rotor may be disposed in the stator while being spaced apart therefrom, the impeller may be coupled to a rotating shaft of the rotor, and the impeller casing may be coupled to the housing to cover and block the impeller. The fluid may thus be pumped by rotation of the impeller.
• However, the impeller of the water pump may generally have a plurality of blades arranged at equal intervals, and significant noise may thus occur due to the rotation of the impeller when the water pump is operated to pump the fluid.
RELATED ART DOCUMENT Patent Document
• KR 10-2017-0046238 A (May 2, 2017)
SUMMARY
• Embodiments of the present disclosure are directed to providing an impeller for a water pump which may reduce noise occurring when the impeller is rotated.
• In one general aspect, an impeller for a water pump includes: a main plate; and a plurality of blades arranged on one surface of the main plate, and spaced apart from each other in a circumferential direction of the main plate, wherein the plurality of blades are non-equal interval types in which the blades are spaced apart from each other at intervals not equal to each other.
• The blade interval at which the plurality of blades are spaced apart from each other may have an angle at which tips of the plurality of blades are spaced apart from each other.
• The blade intervals adjacent to each other may be different from each other.
• The blade intervals may be all different from each other.
• The plurality of blades may have blade intervals formed different from each other and positioned opposite to each other based on a center of the main plate.
• The blade intervals may be arranged randomly with no regularity.
• The plurality of blades may have different curved degrees.
• The plurality of blades may have different thicknesses.
• When “N” indicates the number of blades and “A” indicates the blade interval, the blade interval may be formed within an angle range that satisfies Equation 1 below:
• $\begin{array}{cc}\frac{360°}{N}\times 0.9\le A\le \frac{360°}{N}\times 1.1.& \left(\mathrm{Equation}1\right)\end{array}$
• In another general aspect, a water pump includes: a motor housing having a shape of a container with an open upper side; a stator positioned in the motor housing; a lower casing coupled to the upper side of the motor housing, and including a rotor accommodating part that protrudes downward, has a rotor accommodating space concave downward from an upper surface thereof, and is inserted into the stator; an upper casing coupled to an upper side of the lower casing, having an impeller accommodating space by being coupled with the lower casing, and including an inlet through which a fluid is introduced and an outlet through which the fluid is discharged by communicating with impeller accommodating space; the impeller for a water pump of claim 1 rotatably positioned in the impeller accommodating space; and a rotor rotatably positioned in the rotor accommodating space of the lower casing and coupled to the impeller.
• The impeller for a water pump may further include a lower plate positioned opposite to the main plate and coupled to the plurality of blades, and the main plate and the plurality of blades of the impeller for a water pump may be integrally formed with each other, and the lower plate may be integrally formed with the rotor.
• The impeller for a water pump may have a through hole positioned in a center of the main plate and passing through both sides thereof.
• Other features and aspects will be apparent from the following detailed description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIGS. 1 to 3 are a perspective view, an upper plan view, and a lower plan view showing an impeller for a water pump according to an embodiment of the present disclosure, respectively.
• FIG. 4 is a plan view showing an equal-interval type impeller whose blades have the equal intervals therebetween according to the prior art.
• FIG. 5 is a plan view showing a non-equal interval type impeller whose blades have non-equal intervals therebetween according to an embodiment of the present disclosure.
• FIG. 6 is a graph showing measured noise of a water pump using the prior equal-interval type impeller of FIG. 4 .
• FIG. 7 is a graph showing measured noise of a water pump using the non-equal interval type impeller according to the present disclosure of FIG. 5 .
• FIG. 8 is data showing the noise of the water pump using the prior equal-interval type impeller of FIG. 4 and the noise of the water pump using the non-equal interval type impeller according to the present disclosure of FIG. 5 .
• FIG. 9 is test data of performances of the water pump using the prior equal-interval type impeller and the water pump using the non-equal interval type impeller according to the present disclosure.
• FIGS. 10 to 12 are an assembled perspective view, an exploded perspective view, and a front sectional view showing a water pump including the impeller for a water pump according to another embodiment of the present disclosure, respectively.
DETAILED DESCRIPTION OF EMBODIMENTS
• Hereinafter, an impeller for a water pump of the present disclosure is described in detail with reference to the accompanying drawings.
• FIGS. 1 to 3 are a perspective view, an upper plan view, and a lower plan view showing an impeller for a water pump according to an embodiment of the present disclosure, respectively.
• As shown in the drawings, the impeller for a water pump according to an embodiment of the present disclosure may roughly include a main plate 510 and a plurality of blades 530.
• Referring to FIGS. 1 to 3 , the main plate 510 may have a disc shape, for example, and include a through hole 501 passing through both sides thereof for a fluid to pass through its center. In addition, the main plate 510 may slightly protrude toward the other side (downward) from the outside to the inside in a radial direction, and the through hole 501 may extend from an inner end of the main plate 510 to the other side in the radial direction. The main plate 510 may have any of various other shapes.
• The plurality of blades 530 may be arranged on one surface of the main plate 510, and spaced apart from each other in a circumferential direction of the main plate 510. In addition, the plurality of blades 530 may have a root part, which is the inner end thereof in the radial direction, disposed to be spaced apart from the center of the main plate 510, and a tip, which is an outer end thereof in the radial direction, disposed to be coincident with the outer end of the main plate 510 in the radial direction. In addition, the plurality of blades 530 may have a curved shape curved from the root to the tip in one direction, and a shape of a curved plate having a thickness smaller than its height. The plurality of blades 530 may have any of various other shapes.
• Here, the plurality of blades 530 may be a non-equal interval type in which the blades 530 are spaced apart from each other at intervals not equal to each other. For example, when the interval at which the plurality of blades 530 are spaced apart from each other is referred to as a blade interval, the blade interval may have an angle at which the tips of the plurality of blades 530 are spaced apart from each other. That is, the blade interval of any two adjacent blades 530 may not be the same as each other. In other words, any one or more of the blade intervals may be different from the rest blade intervals.
• Therefore, when the impeller for a water pump according to the present disclosure is used in a water pump to pump the fluid, some frequency noise component occurring by each blade during rotation of the impeller may not overlap each other, thus reducing the noise.
• In addition, in the impeller for a water pump according to the present disclosure, the blade intervals adjacent to each other may be different from each other. That is, as shown in the drawings, it may be seen that the separation angles between two adjacent blades may be different from each other. It is thus possible to further reduce the overlapping of the frequency components of the noise occurring by each blade during the rotation of the impeller.
• In addition, in the impeller for a water pump according to the present disclosure, the blade intervals may be all different from each other. That is, all the blade intervals may be different from each other. For example, when A1 to A9 respectively indicate the blade intervals, all of A1 to A9 may have different angles. In addition, the blade intervals may be arranged randomly with no particular regularity.
• Therefore, when the impeller for a water pump according to the present disclosure is used in the water pump to pump the fluid, any frequency noise component occurring by each blade during the rotation of the impeller may not overlap each other, thus significantly reducing the noise.
• In addition, the plurality of blades 530 may have blade intervals formed different from each other and positioned opposite to each other based on the center of the main plate 510. For example, the blade intervals A5 and A6 positioned opposite to any blade interval A1 may respectively be different from the blade interval A1.
• Therefore, when the impeller for a water pump according to the present disclosure is used in the water pump to pump the fluid, frequency noise component corresponding to half of a rotational speed of the impeller during the rotation of the impeller may not overlap each other, thus reducing the noise.
• In addition, the plurality of blades 530 may have different curved degrees or different thicknesses. That is, the blade 530 may have a changed position of the tip by having the different curved degree or the different thickness in a state where the angles at which the blades 530 are arranged are the same as each other. Accordingly, the blade intervals may be different from each other.
• In addition, when “N” indicates the number of blades 530 and “A” indicates the blade interval, the blade interval may be formed within an angle range that satisfies Equation 1 below.
• $\begin{array}{cc}\frac{360°}{N}\times 0.9\le A\le \frac{360°}{N}\times 1.1& \left(\mathrm{Equation}1\right)\end{array}$
• Here, the water pump may have increased pulsation and vibration and lower efficiency when the blade interval A is out of the range of Equation 1 above. Therefore, when the blade interval is set within an appropriate range as shown in Equation 1 above, it is possible to reduce the vibration and noise during the rotation of the impeller, and also secure reliable performance of the water pump using the impeller of the present disclosure.
• FIG. 4 is a plan view showing an equal-interval type impeller whose blades have the equal intervals therebetween according to the prior art; and FIG. 5 is a plan view showing the non-equal interval type impeller whose blades have the non-equal intervals therebetween according to an embodiment of the present disclosure. FIGS. 4 and 5 show conditions where the impellers have the same size as each other, each include the same number of blades, i.e., seven blades, and have only different blade intervals.
• In addition, FIG. 6 is a graph showing measured noise of a water pump using the prior equal-interval type impeller of FIG. 4 ; FIG. 7 is a graph showing measured noise of a water pump using the non-equal interval type impeller according to the present disclosure of FIG. 5 ; and FIG. 8 is data showing comparison of the noise of the water pump using the prior equal-interval type impeller and the noise of the water pump using the non-equal interval type impeller according to the present disclosure.
• As shown in the drawings, it may be seen that the water pump has the 7th and 14th noise generally reduced when using the non-equal interval type impeller of the present disclosure compared to when using the prior equal-interval type impeller, in particular, the 7th noise in an X direction and 14th noise in a Z direction, significantly reduced.
• FIG. 9 is test data of performances of the water pump using the prior equal-interval type impeller and the water pump using the non-equal interval type impeller according to the present disclosure.
• As shown in the drawing, it may be seen that the water pump using the non-equal interval type impeller of the present disclosure has almost no differences from the water pump using the prior equal-interval type impeller in terms of various performances, such as flow rate, fluid pressure, and current, or the like for each rotational speed. Therefore, the water pump using the non-equal interval type impeller of the present disclosure may reduce the noise and vibration while sufficiently securing the required performance.
• FIGS. 10 to 12 are an assembled perspective view, an exploded perspective view, and a front sectional view showing the water pump including the impeller for a water pump according to another embodiment of the present disclosure, respectively.
• As shown in the drawings, the water pump of the present disclosure may include a motor housing 300, a stator 100, a lower casing 210, an upper casing 600, the impeller 500 for a water pump, and a rotor 400.
• The motor housing 300 may have a shape of a concave container made of a metal material, an empty inside, and an open upper side. In addition, the motor housing 300 may have a blocked lower end and a side having a cylindrical shape, and a flange may protrude outward from an outer circumferential surface of an upper end thereof in a radial direction.
• The stator 100 may include a core 110, a plurality of teeth 120, an insulator 130, a coil 140, and a plurality of terminals 150. The stator 100 may be a stator used for a generally used motor, a brushless direct current (BLDC) motor, or the like, and may be any of various other types.
• The lower casing 210 may have a lower setting groove 211 concave downward from an upper surface thereof to accommodate a portion of the impeller 500, and a concave lower passage groove 212 positioned outside the lower setting groove 211 in a radial direction for a fluid discharged from the impeller 500 to flow. The rotor accommodating part 220 may be integrally formed with the lower casing 210 by injection molding, and have a shape of a concave container protruding downward from a center of a portion in which the lower seating groove 211 is positioned. In addition, in the rotor accommodating part 220, a lower bearing mounting part 222 may be positioned at a lower bottom of a rotor accommodating space 221, and a lower bearing 411 may be coupled to the lower bearing mounting part 222. Here, the lower bearing 411 may include a bushing B which may support a lower end of a rotating shaft 410 of the rotor 400 in the radial direction, and a support pin P which may support the lower end of the rotating shaft 410 in an axial direction. Thus, the rotor 400 may be inserted into the rotor accommodating space 221 inside the rotor accommodating part 220, and an outer circumferential surface of the rotor 400 may be spaced apart from an inner circumferential surface of the rotor accommodating part 220. The lower end of the rotor 400 may thus be coupled to the lower bearing 411, and the rotor 400 may thus be smoothly rotated. In addition, the rotor accommodating part 220 of the lower casing 210 may be inserted into and coupled to the stator 100.
• The upper casing 600 may be coupled to an upper side of the lower casing 210, and have an impeller accommodating space 601 accommodating the impeller 500 by being coupled with the lower casing 210. In addition, an upper seating groove 630 may be positioned concave upward in a lower surface of the upper casing 600 to accommodate a portion of the impeller 500, and the lower seating groove 211 and the upper seating groove 630 may form the impeller accommodating space 601. In addition, a concave upper passage groove 632 may be positioned to correspond to the lower passage groove 212 of the lower casing 200 in the lower surface of the upper casing 600 for the fluid discharged from the impeller 500 to flow. In addition, the upper casing 600 may have an open center in a vertical direction. Therefore, the upper seating groove 630 and an inlet 610 may communicate with each other, and an outlet 620 may be connected to the upper passage groove 632 and the lower passage groove 212. In addition, an upper bearing mounting part 602 may be positioned inside the inlet 610 of the upper casing 600, and an upper bearing 412 may be coupled to the upper bearing mounting part 602. Here, the upper bearing mounting part 602 may be disposed in a portion in which an inflow passage 611 is positioned, and the upper bearing mounting part 602 may be fixed to a support part 612 protruding from an inner circumferential surface of the inflow passage 611, and the fluid may thus smoothly pass between the support parts 612 to be introduced into the impeller 500. Here, the upper bearing 412 may include the bushing B which may support an upper end of the rotating shaft 410 of the rotor 400 in the radial direction, and the support pin P which may support the upper end of the rotating shaft 410 in the axial direction. The upper end of the rotor 400 may thus be coupled to the upper bearing 412, and the rotor 400 may thus be smoothly rotated.
• The impeller 500 may serve to pump the fluid introduced into the inlet 610 of the upper casing 600 toward the outlet 620 by the rotation. For example, the impeller 500 may include the main plate 510 and the plurality of blades 530 integrally formed with each other, and further include a lower plate 520 integrally formed with a core part of the rotor 400. Therefore, the plurality of blades 530 may have one side coupled to the main plate 510 and the other side coupled to the lower plate 520. A through hole 501 positioned in the main plate 510 may communicate with the inlet 610 of the upper casing 600. In addition, an outer circumference of the impeller 500 may be disposed close to the lower groove passage 212 and the upper passage groove 632, and the fluid discharged from the impeller 500 may thus pass through a discharge passage 621 positioned by the passage grooves to be discharged through the outlet 620 of the upper casing 600.
• The fluid introduced into the inlet 610 of the upper casing 600 may thus be introduced into the impeller 500 through the inflow passage 611 and the through hole 501 in an upper center of the impeller 500, may then have increased pressure by a centrifugal force generated by the rotation of the impeller 500 to flow into the discharge passage 621, and then flow along the discharge passage 621 to be discharged to the outside through the outlet 620.
• As described above, the rotor 400 may be rotatably accommodated in the rotor accommodating space 221 of the lower casing 210, and an outer circumferential surface of the rotor 400 may be spaced apart from an inner circumferential surface of the rotor accommodating part 220.
• As set forth above, the impeller for a water pump according to the present disclosure may reduce the noise occurring when the impeller is rotated by using a simple configuration of the changed intervals between the arranged blades.
• The present disclosure is not limited to the above-described embodiments, and 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.

Claims (12)

What is claimed is:

1. An impeller for a water pump, the impeller comprising:

a main plate; and

a plurality of blades arranged on one surface of the main plate, and spaced apart from each other in a circumferential direction of the main plate,

wherein the plurality of blades are non-equal interval types in which the blades are spaced apart from each other at intervals not equal to each other.

2. The impeller of claim 1, wherein the blade interval at which the plurality of blades are spaced apart from each other has an angle at which tips of the plurality of blades are spaced apart from each other.

3. The impeller of claim 2, wherein the blade intervals adjacent to each other are different from each other.

4. The impeller of claim 3, wherein the blade intervals are all different from each other.

5. The impeller of claim 2, wherein the plurality of blades have blade intervals formed different from each other and positioned opposite to each other based on a center of the main plate.

6. The impeller of claim 2, wherein the blade intervals are arranged randomly with no regularity.

7. The impeller of claim 2, wherein the plurality of blades have different curved degrees.

8. The impeller of claim 2, wherein the plurality of blades have different thicknesses.

9. The impeller of claim 2, wherein when “N” indicates the number of blades and “A” indicates the blade interval, the blade interval is formed within an angle range that satisfies Equation 1 below:

$\begin{array}{cc}\frac{360°}{N}\times 0.9\le A\le \frac{360°}{N}\times 1.1.& \left(\mathrm{Equation}1\right)\end{array}$

10. A water pump comprising:

a motor housing having a shape of a container with an open upper side;

a stator positioned in the motor housing;

a lower casing coupled to the upper side of the motor housing, and including a rotor accommodating part that protrudes downward, has a rotor accommodating space concave downward from an upper surface thereof, and is inserted into the stator;

an upper casing coupled to an upper side of the lower casing, having an impeller accommodating space by being coupled with the lower casing, and including an inlet through which a fluid is introduced and an outlet through which the fluid is discharged by communicating with impeller accommodating space;

the impeller for a water pump of claim 1 rotatably positioned in the impeller accommodating space; and

a rotor rotatably positioned in the rotor accommodating space of the lower casing and coupled to the impeller.

11. The pump of claim 10, wherein the impeller for a water pump further includes a lower plate positioned opposite to the main plate and coupled to the plurality of blades, and

the main plate and the plurality of blades of the impeller for a water pump are integrally formed with each other, and the lower plate is integrally formed with the rotor.

12. The pump of claim 11, wherein the impeller for a water pump has a through hole positioned in a center of the main plate and passing through both sides thereof.

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