US20240225393A1

US20240225393A1 - Impeller and cleaner using same

Info

Publication number: US20240225393A1
Application number: US18/612,177
Authority: US
Inventors: Masayuki Takada; Minoru Yoshida
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2021-10-29
Filing date: 2024-03-21
Publication date: 2024-07-11

Abstract

A cleaner including a body, a dust case, a shaft, a motor to rotate the shaft, and an impeller that rotates by the rotation of the rotation shaft by the motor to generate a suction force for suctioning air into the body from the dust case through an air passage, the impeller including: a boss portion fixed to the shaft, a base portion extended from the boss portion and having a diameter that increases from an intake side toward a discharge side of the air passage, and a plurality of blades on the base portion, each blade including: a wind cutting edge having a proximal end, and a protruding end, is behind the proximal end in a rotation direction of the impeller, and is closer to the intake side than the boss portion and a wind sending edge that is farther from the boss portion than the wind cutting edge.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of International Application No. PCT/KR2022/013059, filed Aug. 31, 2022, which is incorporated herein by reference in its entirety, it being further noted that foreign priority benefit is based upon Japanese Patent Application No. 2021-177920, filed Oct. 29, 2021, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The disclosed technology relates to an impeller and a cleaner using the same.

BACKGROUND ART

Recently, many small and lightweight stick type cleaners that do not include a cleaner body, hose, and electric cord have been released. Such cleaners are popular because they are cordless and easy to handle.
The stick type cleaners are equipped with a small impeller having a diameter of about 3 cm to about 5 cm. In order to generate a high suction force with such a small impeller, a small and lightweight motor capable of rotating at high speed of 50,000 r/min or more while delivering a certain amount of torque has been used as a motor for rotating the impeller.
Japanese Patent No. 3724413 and Japanese Laid-Open Patent Application No. 2017-82759 disclose small impellers used in such cleaners.

DISCLOSURE

Technical Solution

According to an aspect of the disclosure, a cleaner can include a main body, a dust case, a rotation shaft, a fan motor to rotate the rotation shaft, and an impeller that rotates by the rotation of the rotation shaft by the fan motor to generate a suction force for suctioning air into the main body from the dust case through an air passage, the impeller can include: a boss portion fixed to the rotation shaft, a base portion extending from the boss portion and having a diameter that increases from an intake side of the air passage toward a discharge side of the air passage, and a plurality of blades on the base portion, each blade of the plurality of blades can include: a wind cutting edge that has a proximal end at the base portion, and a protruding end that can be opposite to the proximal end, can be behind the proximal end in a rotation direction of the impeller, and can be closer to the intake side than the proximal end is to the intake side, and a wind sending edge that can be farther from the boss portion than the wind cutting edge is from the boss portion.
According to an aspect of the disclosure, the main body may be provided with a filtration chamber and an exhaust chamber.
According to an aspect of the disclosure, the wind cutting edge can have a swept-back angle with respect to a reference line passing through a center of rotation of the impeller and the proximal end of the wind cutting edge in a radial direction in a range of 15° to 19°.
According to an aspect of the disclosure, the wind cutting edge can have an inclination angle with respect to a reference line that can be orthogonal to a rotation axis of the impeller in a range of 18° to 26°.
According to an aspect of the disclosure, the wind sending edge extends from an upper surface of the base portion at an angle relative to a direction orthogonal to the upper surface and opposite of the rotation direction.
According to an aspect of the disclosure, the plurality of blades can be on an upper surface of the base portion which can be sloped toward the discharge side of the air passage while extending toward a circumferential side of the impeller in a radial direction from the boss portion.
According to an aspect of the disclosure, the upper surface can have an inclination angle with respect to a rotation axis of the impeller in a range of 20° to 40°.
According to an aspect of the disclosure, the plurality of blades can include at least one of a mixed flow fan structure and a centrifugal fan structure.
According to an aspect of the disclosure, the cleaner can further include: an upstream shroud at least partially upstream of the impeller and including: a first diameter portion having a first diameter larger than an intake side of the impeller, and a first diameter reduction portion which extends from the first diameter portion toward the intake side of the impeller and has a first reduction diameter that decreases from the first diameter portion toward the intake side of the impeller, and a downstream shroud at least partially downstream of the impeller and including: a second diameter portion having a second diameter larger than a discharge side of the impeller, and a second diameter reduction portion which extends from the second diameter portion toward the intake side of the impeller and has a second reduction diameter that decreases from the second diameter portion toward the intake side of the impeller, and the impeller can be in the second diameter reduction portion.
According to an aspect of the disclosure, the cleaner can further include: a diffuser in the second diameter portion.
According to an aspect of the disclosure, an impeller can include a boss portion fixable to a rotation shaft of a fan motor so that the impeller can be rotatable by rotation of the rotation shaft by the fan motor to generate a suction force for suctioning air through an air passage, a base portion extending from the boss portion and having a diameter that, when the boss portion is fixed to the rotation shaft so that the impeller can be rotatable by rotation of the rotation shaft by the fan motor to generate the suction force for suctioning air through the air passage, increases from an intake side of the air passage toward a discharge side of the air passage, and a plurality of blades on the base portion, each blade of the plurality of blades including: a wind cutting edge that has a proximal end at the base portion, and a protruding end that can be opposite to the proximal end, can be behind the proximal end in a rotation direction of the impeller, and, when the boss portion is fixed to the rotation shaft so that the impeller is rotatable by rotation of the rotation shaft by the fan motor to generate the suction force for suctioning air through the air passage, can be closer to the intake side of the air passage than the proximal end is to the intake side of the air passage, and a wind sending edge that can be farther from the boss portion than the wind cutting edge is from the boss portion.
According to an aspect of the disclosure, the wind cutting edge can have a swept-back angle with respect to a reference line passing through a center of rotation of the impeller and the proximal end of the wind cutting edge in a radial direction in a range of 15° to 19°.
According to an aspect of the disclosure, the wind cutting edge can have an inclination angle with respect to a reference line that can be orthogonal to a rotation axis of the impeller in a range of 18° to 26°.
According to an aspect of the disclosure, the plurality of blades can be on an upper surface of the base portion which, when the boss portion is fixed to the rotation shaft so that the impeller is rotatable by rotation of the rotation shaft by the fan motor to generate the suction force for suctioning air through the air passage, can be sloped toward the discharge side of the air passage while extending toward a circumferential side of the impeller in a radial direction from the boss portion.
According to an aspect of the disclosure, the upper surface can have an inclination angle with respect to a rotation axis of the impeller in a range of 20° to 40°.
According to an aspect of the disclosure, the plurality of blades can include at least one of a mixed flow fan structure and a centrifugal fan structure.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view showing a main portion of a stick type cleaner according to an embodiment of the disclosure.

FIG. 2 schematically shows an internal structure of a main body according to an embodiment of the disclosure.

FIG. 3 shows a perspective view and a schematic cross-sectional view of a structure of an impeller according to an embodiment of the disclosure.

FIG. 4 is a view for describing a structure of an impeller according to an embodiment of the disclosure, seen in an intake side.

FIG. 5 is a schematic diagram of an example of a fluid analysis model of an impeller according to an embodiment of the disclosure.

FIG. 6 is a graph showing an example of a relationship between inclination angles of a wind cutting edge and suction efficiency according to results of fluid analysis.

FIG. 7 is a diagram showing examples of fluid analysis results according to swept-back angles of a wind cutting edge.

FIG. 8 is a graph showing an example of a relationship between swept-back angles of a wind cutting edge and suction efficiency according to results of fluid analysis.

FIG. 9 is a schematic view of a stick type cleaner according to an embodiment of the disclosure.

MODE FOR INVENTION

Although general terms currently widely used were selected as terminology used in the present specification while considering the functions of the disclosure, they may vary according to intentions of one of ordinary skill in the art, judicial precedents, the advent of new technologies, and the like. Terms arbitrarily selected by the applicant of the disclosure may also be used in a specific case, and in this case, their meanings will be given in detail in the detailed description of the disclosure. Hence, the terms used in the disclosure must be defined based on the meanings of the terms and the contents of the entire specification, not by simply stating the terms themselves. In the entire specification, it will be understood that when a certain part “includes” a certain component, the part does not exclude another component but can further include another component, unless the context clearly dictates otherwise.
Terminology such as “at least one of A and B” or “at least one of A or B”, as used herein, includes any of the following: A, B, A and B.
Terminology such as “at least one of A, B, and C” or “at least one of A, B, or C”, as used herein, includes any of the following: A, B, C, A and B, A and C, B and C, A and B and C.
Hereinafter, embodiments of an impeller according to the disclosure and a cleaner adopting the same will be described in detail to be easily embodied by one of ordinary skill in the technical field to which the disclosure belongs. However, the disclosure may be implemented in various different forms, and is not limited to the embodiments which will be described below. Also, in the drawings, parts that are irrelevant to the descriptions may be not shown in order to clearly describe the disclosure, and throughout the specification, similar portions are assigned similar reference numerals.
FIG. 1 is a schematic view showing a main portion of a stick type cleaner according to an embodiment of the disclosure. Hereinafter, a stick type cleaner is referred to as a cleaner 1. The cleaner 1 maybe of a wireless type.
An impeller 20 (see FIG. 2 ) according to an embodiment of the disclosure may be installed in the cleaner 1. The cleaner 1 according to an embodiment of the disclosuremay include a main body 3 and a dust case 4 connected to the main body 3. The cleaner 1 according to an embodiment of the disclosure may further include a pipe 2 and a handle 5.
The pipe 2 may be an elongated, cylindrical member. A head of the cleaner 1 for suctioning dust may be installed at an end (not shown) of the pipe 2, which is not shown. Another end of the pipe 2 may be connected to the dust case 4. The main body 3 and the handle 5 may be integrated with a proximal end portion of the pipe 2. A suction unit 10 (see FIG. 2 ) which will be described below may be accommodated in the main body 3. A battery, a controller, etc. may be accommodated in the handle 5, which are not shown. The controller may control driving of the suction unit 10. The battery may be a rechargeable secondary battery and supply electrical energy to the suction unit 10. The handle 5 may be a part that a user holds. The cleaner 1 according to an embodiment of the disclosure may be configured such that the user is capable of using the cleaner 1 while holding the handle 5 with one hand.
The dust case 4 may be installed below the main body 3. The dust case 4 may be detachable from the main body 3. While the suction unit 10 is driven, a strong suction force may be generated in the head. Accordingly, dust suctioned through the head may be collected in the dust case 4 through the pipe 2.
FIG. 2 schematically shows an internal structure of the main body 3 according to an embodiment of the disclosure. FIG. 2 shows an internal structure of a part surrounded by line L1 in FIG. 1 . Also, in FIG. 2 , the diffuser 15 is shown in an external shape on the left side from a rotation axis A and in a cross-sectional shape on the right side from the rotation axis A.
The main body 3 may include an exhaust chamber 30, a filtration chamber 31, etc. The exhaust chamber 30 may be a cylindrical space with a closed end, and a plurality of inner exhaust holes 30 a may be formed along a circumference of the exhaust chamber 30. The filtration chamber 31 may surround the exhaust chamber 30. In the filtration chamber 31, a cylindrical filter 32 for capturing dust may be positioned around an entire circumference of the filtration chamber 31. In a cover 34 of the main body 3, which forms an outer circumferential boundary of the filtration chamber 31, a plurality of outer exhaust holes 33 may be formed, as shown in FIGS. 1 and 2 . The suction unit 10 may be accommodated inside the main body 3 in a state in which a portion of the suction unit 10 is inserted in the exhaust chamber 30.
The suction unit 10 may include a fan motor (electric motor) 13 and an impeller 20. The impeller 20 may be positioned in the main body 3 and generate a suction force for suctioning air from the dust case 4 to the main body 3 through the air passage 50 while rotating. The fan motor 13 may rotate the impeller 20. The fan motor 13 and the impeller 20 may have a common rotation axis A. The suction unit 10 may be provided with an upstream shroud 11 and a downstream shroud 12 that form a flow path (air passage 50) through which air flows.
The upstream shroud 11 may be a cylindrical member, and include a first large diameter portion 11 a with a large diameter, and a first diameter reduction portion 11 b which extends from the first large diameter portion 11 a and has a diameter that decreases gradually from the first large diameter portion 11 a. The first diameter reduction portion 11 b may be positioned downstream of the first large diameter portion 11 a in an air flow direction Y1. The first diameter reduction portion 11 b may extend from the first large diameter portion 11 a such that the diameter of the first diameter reduction portion 11 b decreases gradually from the first large diameter portion 11 a in the air flow direction Y1.
The downstream shroud 12 may also be a cylindrical member, and include a second large diameter portion 12 a with a large diameter, and a second diameter reduction portion 12 b which extends from the second large diameter portion 12 a and has a diameter that decreases gradually from the second large diameter portion 12 a. The second diameter reduction portion 12 b may be positioned upstream of the second large diameter portion 12 a in the air flow direction Y1. The diameter of the second diameter reduction portion 12 b may gradually increase in the air flow direction Y1, and the second large diameter portion 12 a may extend from a downstream end of the second diameter reduction portion 12 b. The second large diameter portion 12 a may be connected to the exhaust chamber 30. The second diameter reduction portion 12 b may extend from the second large diameter portion 12 a such that the diameter of the second diameter reduction portion 12 b decreases gradually from the second large diameter portion 12 a in an opposite direction of the air flow direction Y1, and the second diameter reduction portion 12 b may be connected to the first diameter reduction portion 11 b. A first diameter of the first large diameter portion 11 a may be equal to or different from a second diameter of the second large diameter portion 12 a.
The first diameter reduction portion 11 b of the upstream shroud 11 may be connected to the second diameter reduction portion 12 b of the downstream shroud 12. In an embodiment of the disclosure, the upstream shroud 11 may be integrated with the downstream shroud 12 with centers aligned. The first large diameter portion 11 a may be connected to the dust case 4, and the upstream shroud 11 may communicate with the dust case 4. The downstream shroud 12 may be positioned inside the exhaust chamber 30.
The fan motor 13 may be accommodated in the upstream shroud 11, in a state in which a shaft 13 a of the fan motor 13 is toward the downstream shroud 12 and the center of the upstream shroud 11 is aligned with the rotation axis A. The fan motor 13 may be very small. For example, the fan motor 13 according to an embodiment to the disclosure may have a size (so-called palm size) corresponding to an outer diameter of about 70 mm and a height of about 40 mm. Accordingly, the fan motor 13 may also be very light in weight. The fan motor 13 may have a structure capable of obtaining high efficiency and high output to provide sufficient performance to be used in the cleaner 1 with power of a battery. For example, the fan motor 13 according to an embodiment of the disclosure may have a structure capable of rotating, with consumption power of 600 W, at high speed of 50,000 r/min or more, even at ultra-high speed of 100,000 r/min or more, and obtaining suction power of 250 W or more.
The impeller 20 may be positioned in the air passage 50, for example, in the second diameter reduction portion 12 b. The impeller 20 may be accommodated in the second diameter reduction portion 12 b. The impeller 20 may include a boss portion 21 fixed to the shaft 13 a of the fan motor 13 that is aligned with the rotation axis A, a base portion 22 extending around the boss portion 21 and ring-shaped, and a plurality of blades 23 positioned on an upper surface of the base portion 22. The disclosure may particularly focus on a structure of the impeller 20. Details about the structure of the impeller 20 will be described below.
The suction unit 10 may include a diffuser 15. The diffuser 15 may be positioned downstream of the impeller 20. For example, the diffuser 15 may be accommodated in the second large diameter portion 12 a of the downstream shroud 12. The diffuser 15 according to an embodiment of the disclosure may have a two-stage structure of an upper diffuser 15U and a lower diffuser 15D. The diffuser 15 may be a one-stage diffuser 15 according to specifications of the suction unit 10.
Each of the upper diffuser 15U and the lower diffuser 15D may be a cylindrical member, and a plurality of vanes 15 a extending obliquely with respect to an axial direction (for example, the rotation axis A) may be formed on the circumferential surface of each of the upper diffuser 15U and the lower diffuser 15D. An inclination angle of the vanes 15 a in the lower diffuser 15D may be smaller than that of the vanes 15 a in the upper diffuser 15U. Each of the upper diffuser 15U and the lower diffuser 15D may be fixed to an inner circumferential surface of the second large diameter portion 12 a.
During an operation of the cleaner 1, the fan motor 13 may rotate to thereby rotate the impeller 20 at high speed in a preset rotation direction. Accordingly, as indicated by an arrow Y1, air may enter the upstream shroud 11 from the dust case 4, and thus, a suction force may be generated at a upstream side of the second diameter reduction portion 12 b. The air entered the upstream shroud 11 may pass through the first large diameter portion 11 a and the first diameter reduction portion 11 b while air-cooling the fan motor 13 and be suctioned into the second diameter reduction portion 12 b.
The air entered the second diameter reduction portion 12 b through an intake side 50 a may pass through a space between an inner wall surface 12 c of the second diameter reduction portion 12 b and the base portion 22 of the impeller 20 (specifically, between the blades 23), be discharged from the second diameter reduction portion 12 b, and enter the second large diameter portion 12 a. The air entered the second large diameter portion 12 a through a discharge side 50 b of the second diameter reduction portion 12 b may pass through a space between an inner wall surface of the second large diameter portion 12 a and circumferential surfaces of the upper diffuser 15U and the lower diffuser 15D (specifically, between the vanes 15 a) and enter the exhaust chamber 30.
The air rectified in the axial direction as indicated by an arrow Y2 by passing through the upper diffuser 15U and the lower diffuser 15D may enter the exhaust chamber 30. The air entered the exhaust chamber 30 may be discharged to the filtration chamber 31 through the inner exhaust holes 30 a, pass through the filter 32, and then be exhausted to outside of the main body 3 through the outer exhaust holes 33, as indicated by an arrow Y3.
In order to realize a higher suction force, the fan motor 13 may rotate at high speed, and accordingly, the impeller 20 may also be required to have high performance. The disclosure may provide the impeller 20 having a small size, suitable for the stick type cleaner 1, and capable of improving a suction force.
FIG. 3 is a perspective view and a schematic cross-sectional view showing a structure of the impeller 20 according to an embodiment of the disclosure. FIG. 4 is a view for describing a structure of the impeller 20 according to an embodiment of the disclosure, wherein the impeller 20 is seen in the intake side 50 a. As described above, the impeller 20 may include the boss portion 21, the base portion 22, and the plurality of blades 23. For convenience of descriptions, as shown in FIG. 3 , a side of the protruding end 21 a of the boss portion 21, in other words, the intake side 50 a of the air passage 50 is referred to as an upper side, and an opposite side thereof is referred to as a ‘lower side’.
More specifically, the impeller 20 may include the boss portion 21 fixed to the shaft 13 a, the base portion 22 ring-shaped and connected to the boss portion 21, wherein the diameter of the base portion 22 increases from the intake side 50 a of the air passage 50 toward the discharge side 50 b, and the plurality of blades 23 arranged radially on the upper surface of the base portion 22 and generating a suction force in the intake side 50 a of the air passage 50. The impeller 20 may be a resin molded product, and the boss portion 21, the base portion 22, and the plurality of blades 23 may be integrated into one body.
The impeller 20 may rotate in a counterclockwise direction indicated by an arrow Yr in FIGS. 3 and 4 , as seen from above, by driving of the fan motor 13. Also, each blade 23 of the impeller 20 may be inclined such that the circumference side, for example, the wind sending edge 23 b is positioned behind the center side, for example, the wind cutting edge 23 a in the rotation direction Yr, and may have a structure in which air passes between the blades 23 in a direction inclined with respect to the rotation axis A during rotation. The blade 23 may be referred to as a blade having a mixed flow fan structure. That is, the impeller 20 may correspond to a mixed flow fan.
The boss portion 21 may be a cylindrical portion, and the shaft 13 a may be fixed to a center portion of the boss portion 21. The base portion 22 may be a conical portion extending from an upper portion of the boss portion 21, and an upper surface of the base portion 22 may be inclined gently toward the discharge side 50 b of the air passage 50 while extending toward the circumferential side in a radial direction from the boss portion 21. An inclination angle of the upper surface of the base portion 22 may be about 30°, and range from about 20° to about 40°.
Each blade 23 may be a thin plate portion and protrude upward from the upper surface of the base portion 22. The impeller 20 according to an embodiment of the disclosure may have 9 blades 23 arranged at equidistant intervals in the circumferential direction. Each blade 23 may have an appearance of a strip type in which one 23 a of two edges 23 a and 23 b in the radial direction is long and another one 23 b is very short, and one 23 e of two edges 23 e and 23 f in a vertical direction may be connected to the base portion 22. The longer one (wind cutting edge) 23 a of the two edges 23 a and 23 b in the radial direction may be positioned in the center side of the base portion 22, that is, close to the boss portion 21, and the shorter one (wind sending edge) 23 b may be positioned in the circumferential side of the base portion 22, that is, away from the boss portion 21.
Each of the wind cutting edge 23 a and the wind sending edge 23 b may extend, for example, straightly from the edge 23 e in the vertical direction. Each blade 23 may have a shape twisted from the wind cutting edge 23 a toward the wind sending edge 23 b. A protruding end 23 d of the wind cutting edge 23 a may be inclined while being twisted in the rotation direction, and a protruding end 23 g of the wind sending edge 23 b may be inclined while being twisted in an opposite direction of the rotation direction. The wind cutting edge 23 a may extend, as shown in FIG. 4 , in the radial direction, as seen in the axial direction, that is, as seen from above. Accordingly, the protruded edge 23 f in the vertical direction of each blade 23 may extend along an inner circumferential surface of the second diameter reduction portion 12 b with a small gap from the inner circumferential surface of the second diameter reduction portion 12 b.
The wind cutting edge 23 a may include a proximal end 23 c and a protruding end 23 d. The proximal end 23 c may be an end toward the base portion 22, and the protruding end 23 d may be an opposite end of the proximal end 23 c. In the impeller 20 according to an embodiment of the disclosure, each blade 23 may have a shape (for convenience of description, referred to as a swept-back wing shape) in which the protruding end 23 d of the wind cutting edge 23 a is positioned behind the proximal end 23 c of the wind cutting edge 23 a in the rotation direction. Due to the swept-back wing shape, air resistance of the blade 23 may be reduced, which provides an advantage for high-speed rotation.
Also, the present applicants have found from results of fluid analysis on a swept-back angle θ2 (an angle by which the wind cutting edge 23 a is swept back with respect to a second reference line RL2 passing through a center of rotation of the impeller 20 and the proximal end 23 c of the wind cutting edge 23 a in the radial direction, see FIG. 4 ) of the swept-back wing shape that suction performance may be improved by selecting the swept-back angle θ2. This will be described below.
Also, the impeller 20 according to an embodiment of the disclosure may have the blades 23 each of which the protruding end 23 d of the wind cutting edge 23 a is positioned at a higher location (the intake side 50 a of the air passage 50) than the proximal end 23 c of the wind cutting edge 23 a. More specifically, as schematically shown in FIG. 3 , the wind cutting edge 23 a of each blade 23 may be inclined upward from the proximal end 23 c connected to the boss portion 21 toward the protruding end 23 d.
By forming the wind cutting edge 23 a of each blade 23 in this shape, a blade load at an end of each blade 23 located in an air inlet side may be reduced, and leakage flow may be reduced. Also, the present applicants have found from results of fluid analysis on an inclination angle θ1 (an angle at which the wind cutting edge 23 a is inclined with respect to a first reference line RL1 that is orthogonal to the rotation axis A, see FIG. 3 ) of the wind cutting edge 23 a that suction performance may be improved by selecting the inclination angle θ1 together with the swept-back angle θ2.
FIG. 5 is a schematic diagram of an example of a fluid analysis model of the impeller 20 according to an embodiment of the disclosure. For fluid analysis, after a model of the air passage 50 in which the impeller 20 is accommodated, for example, the second diameter reduction portion 12 b, is set as shown in FIG. 5 , how suction efficiency (suction force/motor output) changes by changing the inclination angle 81 of the wind cutting edge 23 a facing the intake side 50 a of the air passage 50 were investigated, as indicated by arrows in FIG. 5 .
FIG. 6 is a graph showing an example of a relationship between the inclination angle θ1 of the wind cutting edge 23 a and suction efficiency according to results of fluid analysis. The vertical axis may be the suction efficiency and the horizontal axis may be the inclination angle θ1. As the inclination angle 81 increases, the suction efficiency may increase gradually and then decrease. It is seen that the suction efficiency peaks near the inclination angle θ1 of about 22°. More specifically, by setting the inclination angle θ1 of the wind cutting edge 23 a to range from 18° to 26°, the suction efficiency may be optimized.
Accordingly, the inclination angle θ1 of the wind cutting edge 23 a of the impeller 20 according to an embodiment of the disclosure may be set to range from 18° to 26°, and thereby may be optimized to improve a suction force. Although the inclination angle θ1 at which the suction efficiency peaks is most desirable, selecting the inclination angle θ1 within the above-mentioned range according to specifications of the impeller 20 may result in obtaining the same effect that may be obtained at the inclination angle θ1 at which the suction efficiency peaks.
Like the fluid analysis on the inclination angle θ1, after a model as shown in FIG. 5 is set for the swept-back angle θ2 of the wind cutting edge 23 a, how the suction efficiency changes by changing the swept-back angle θ2 were investigated. FIG. 7 is diagrams showing examples of fluid analysis results according to swept-back angles θ2 of the wind cutting edge 23 a.
The diagrams of FIG. 7 show results of flow analysis on air flowing along the second diameter reduction portion 12 b (specifically, between the blades 23) at three different swept-back angles θ2. The diagram (a) of FIG. 7 corresponds to a case in which the swept-back angle θ2 is 27°, the diagram (b) of FIG. 7 corresponds to a case in which the swept-back angle θ2 is 17°, and the diagram (c) of FIG. 7 corresponds to a case in which the swept-back angle θ2 is 7°. In the diagrams (a), (b), and (c) of FIG. 7 , areas R1 with a thick concentration represent areas with a relatively large air flow volume, and areas R2 with a light concentration represent areas with a relatively small air flow volume.
In the diagram (a) of FIG. 7 , corresponding to a great swept-back angle θ2, air flowing between the blades 23 may intend to flow biased to the base portion 22 in a downstream side of the second diameter reduction portion 12 b. Meanwhile, in the diagram (c) of FIG. 7 , corresponding to a small swept-back angle θ2, air flowing between the blades 23 may intend to flow biased to the inner wall surface of the second diameter reduction portion 12 b. Also, in the diagram (b) of FIG. 7 , corresponding to an intermediate swept-back angle θ2, air flowing between the blades 23 may intend to flow along middle spaces between the blades 23 without being biased to the base portion 22 or the inner wall surface of the second diameter reduction portion 12 b.
When air flows biased toward the base portion 22, discharge flow may become non-uniform, and flow separation may occur near the base portion 22 on the discharge side 50 b, resulting in mixing loss in the impeller 20. Accordingly, deterioration in suction force may be caused. When air flows biased to the inner wall surface of the second diameter reduction portion 12 b, leakage flow by which air leaks through the gaps between the blades 23 and the inner wall surface of the second diameter reduction portion 12 b may increase, which causes deterioration in suction force. Meanwhile, when air flows along the middle spaces between the blades 23 without being biased to the base portion 22 or the inner wall surface of the second diameter reduction portion 12 b, a rotation force of the impeller 20 may effectively influence the air, and a suction force may be efficiently generated.
FIG. 8 is a graph showing an example of a relationship between swept-back angles θ2 of the wind cutting edge 23 a and suction efficiency according to results of fluid analysis. As the swept-back angle θ2 increases, the suction efficiency may increase gradually and then decrease gradually. It is seen that the suction efficiency peaks near the swept-back angle θ2 of about 17°. More specifically, it is seen that the suction efficiency is optimized by setting the swept-back angle θ2 of the wind cutting edge 23 a to range from 15° to 19°.
Accordingly, the swept-back angle θ2 of the wind cutting edge 23 a of the impeller 20 according to an embodiment of the disclosure may be set to range from 15° to 19°, and thereby may be optimized to improve a suction force. Although the swept-back angle θ2 at which the suction efficiency peaks is most desirable, selecting the swept back angle θ2 within the above-mentioned range according to specifications of the impeller 20 may result in obtaining the same effect that may be obtained at the swept-back angle θ1 at which the suction efficiency peaks.
In the impeller 20 according to an embodiment of the disclosure, both the inclination angle θ1 and swept-back angle θ2θ2 of the wind cutting edge 23 a may be optimized. Accordingly, these effects may be combined to further improve a suction force. That is, the impeller 20 according to an embodiment of the disclosure may better achieve the performance of a motor that tends to rotate at high speed and generate a great suction force. Accordingly, by combining the impeller 20 according to an embodiment of the disclosure with the fan motor 13 that rotates at high speed, the cleaner 1 having high performance may be implemented.
The impeller 20 according to the disclosure is not limited to the above-described embodiments. For example, in the above-described embodiment, the impeller 20 with the blades 23 of a mixed flow fan structure is illustrated, however, the impeller 20 may include blades 23 of a centrifugal fan structure in which air passes between the blades 23 in the radial direction while the impeller 20 rotates. That is, the impeller 20 may correspond to a centrifugal fan.
Also, in the above-described embodiment of the cleaner 1, the fan motor 13 may be positioned in an upstream side of the impeller 20, however, the fan motor 13 may be positioned in the exhaust chamber 30 that is a downstream side of the impeller 20 in the air flow direction, as shown in FIG. 9 .
In the above-described embodiment, the impeller 20 that rotates in the counterclockwise direction is illustrated, however, the impeller 20 may rotate in a clockwise direction by reversing the direction of the blades 23, according to specifications.
A cleaner according to an aspect of the disclosure may include: a main body including a filtration chamber and an exhaust chamber; a dust case connected to the main body; an impeller positioned in the main body and configured to generate a suction force for suctioning air into the main body from the dust case through an air passage while rotating; and a fan motor configured to rotate the impeller, wherein the impeller may include: a boss portion fixed to a shaft of the fan motor; a base portion which is connected to the boss portion and has a diameter that increases gradually from an intake side of the air passage toward a discharge side of the air passage; and a plurality of blades arranged radially on the base portion and configured to generate a suction force in the intake side of the air passage, wherein each of the plurality of blades may include a wind cutting edge that is close to the boss portion, and a wind sending edge that is distant from the boss portion, the wind cutting edge may include a proximal end that is an end toward the base portion, and a protruding end that is an opposite end of the proximal end, the protruding end may be positioned behind the proximal end in a rotation direction of the impeller, and the protruding end of the wind cutting edge may be positioned closer to the intake side than the proximal end of the wind cutting edge with respect to the air passage. By forming each blade with the above-described shape in the intake side of the impeller, a suction force of the impeller may be improved. That is, by forming each blade in the swept-back wing shape, an advantage for high-speed rotation may be provided, and efficiency may increase. Also, a load on the wing surface may be reduced by slanting the protruding end of the wind cutting edge toward the intake side. By combining these shapes, suction efficiency may increase, and a suction force may be improved.
According to an embodiment, a swept-back angle of the wind cutting edge with respect to a second reference line passing through a center of rotation of the impeller and the proximal end of the wind cutting edge may range from 15° to 19°.
According to an embodiment, an inclination angle of the wind cutting edge with respect to a first reference line that is orthogonal to a rotation axis of the impeller may range from 18° to 26°.
According to fluid analysis, by setting angles as described above, suction efficiency may be optimized, and a suction force may be improved compared to that of a conventional impeller. The impeller of the above-described type may be applied to a cleaner, for example, a stick type cleaner. Also, the above-described impeller may be a motor-driven impeller that may be driven by receiving electric energy from, for example, a battery, and may be applied to a cleaner. According to the impeller which has a very small size and provides a great suction force, a high performance cleaner that is easy to handle may be implemented.
According to an embodiment, the wind sending edge may be inclined while being twisted in an opposite direction of the rotation direction.
According to an embodiment, an upper surface of the base portion on which the plurality of blades are arranged may be inclined gently toward the discharge side of the air passage while extending toward a circumferential side in a radial direction from the boss portion.
According to an embodiment, an inclination angle of the upper surface of the base portion 22 may range from 20° to 40°.
According to an embodiment, the plurality of blades may have any one structure of a mixed flow fan structure and a centrifugal fan structure.
A cleaner according to an embodiment of the disclosure may include: an upstream shroud including a first large diameter portion connected to the dust case, and a first diameter reduction portion which extends from the first large diameter portion and has a diameter that decreases gradually from the first large diameter portion in an air flow direction; and a downstream shroud including a second large diameter portion connected to the exhaust chamber, and a second diameter reduction portion which extends from the second large diameter portion and has a diameter that decreases gradually from the second large diameter portion in an opposite direction of the air flow direction, wherein the impeller may be positioned in the second diameter reduction portion.
The cleaner according to an embodiment of the disclosure may include a diffuser accommodated in the second large diameter portion.
An impeller according to an aspect of the disclosure, which is positioned in an air passage and configured to suction air and discharge the air while rotating, may include: a boss portion fixed to a shaft of a fan motor; a base portion which is connected to the boss portion and has a diameter that increases gradually from an intake side of the air passage toward a discharge side of the air passage; and a plurality of blades arranged radially on the base portion and configured to generate a suction force in the intake side of the air passage, wherein each of the plurality of blades may include a wind cutting edge that is close to the boss portion, and a wind sending edge that is distant from the boss portion, the wind cutting edge may include a proximal end that is an end toward the base portion, and a protruding end that is an opposite end of the proximal end, the protruding end may be positioned behind the proximal end in a rotation direction of the impeller, and the protruding end of the wind cutting edge may be positioned closer to the intake side than the proximal end of the wind cutting edge with respect to the air passage.
According to an embodiment, a swept-back angle of the wind cutting edge with respect to a second reference line passing through a center of rotation of the impeller and the proximal end of the wind cutting edge may range from 15° to 19°.
According to an embodiment, an inclination angle of the wind cutting edge with respect to a first reference line that is orthogonal to a rotation axis of the impeller may range from 18° to 26°.
According to an embodiment, an upper surface of the base portion on which the plurality of blades are arranged may be inclined gently toward the discharge side of the air passage while extending toward a circumferential side in a radial direction from the boss portion.
According to an embodiment, an inclination angle of the upper surface of the base portion 22 may range from 20° to 40°.
According to an embodiment, the plurality of blades may have any one structure of a mixed flow fan structure and a centrifugal fan structure.
So far, although the embodiments have been described by specific embodiments and drawings, it should be interpreted that various modifications and changes are possible by one of ordinary skill in the related art from the above description. In addition, the scope of rights of the disclosure is not limited to these, and various modifications and improvements made by those skilled in the art using the basic concept of the disclosure defined in the following claims also fall within the scope of rights of the disclosure.

Claims

1. A cleaner comprising:

a main body;

a dust case;

a rotation shaft;

a fan motor to rotate the rotation shaft; and

an impeller that rotates by the rotation of the rotation shaft by the fan motor to generate a suction force for suctioning air into the main body from the dust case through an air passage, the impeller including:

a boss portion fixed to the rotation shaft,

a base portion extending from the boss portion and having a diameter that increases from an intake side of the air passage toward a discharge side of the air passage, and

a plurality of blades on the base portion, each blade of the plurality of blades including:

a wind cutting edge that has a proximal end at the base portion, and a protruding end that is opposite to the proximal end, is behind the proximal end in a rotation direction of the impeller, and is closer to the intake side than the proximal end is to the intake side, and

a wind sending edge that is farther from the boss portion than the wind cutting edge is from the boss portion.

2. The cleaner of claim 1, wherein

the wind cutting edge has a swept-back angle with respect to a reference line passing through a center of rotation of the impeller and the proximal end of the wind cutting edge in a radial direction in a range of 15° to 19°.

3. The cleaner of claim 1, wherein

the wind cutting edge has an inclination angle with respect to a reference line that is orthogonal to a rotation axis of the impeller in a range of 18° to 26°.

4. The cleaner of claim 1, wherein

the wind sending edge extends from an upper surface of the base portion at an angle relative to a direction orthogonal to the upper surface and opposite of the rotation direction.

5. The cleaner of claim 1, wherein

the plurality of blades are on an upper surface of the base portion which is sloped toward the discharge side of the air passage while extending toward a circumferential side of the impeller in a radial direction from the boss portion.

6. The cleaner of claim 5, wherein

the upper surface has an inclination angle with respect to a rotation axis of the impeller in a range of 20° to 40°.

7. The cleaner of claim 1, wherein

the plurality of blades include at least one of a mixed flow fan structure and a centrifugal fan structure.

8. The cleaner of claim 1, further comprising:

an upstream shroud at least partially upstream of the impeller and including:

a first diameter portion having a first diameter larger than an intake side of the impeller, and

a first diameter reduction portion which extends from the first diameter portion toward the intake side of the impeller and has a first reduction diameter that decreases from the first diameter portion toward the intake side of the impeller, and a downstream shroud at least partially downstream of the impeller and including:

a second diameter portion having a second diameter larger than a discharge side of the impeller, and

a second diameter reduction portion which extends from the second diameter portion toward the intake side of the impeller and has a second reduction diameter that decreases from the second diameter portion toward the intake side of the impeller, and

the impeller is in the second diameter reduction portion.

9. The cleaner of claim 8, further comprising:

a diffuser in the second diameter portion.

10. An impeller comprising:

a boss portion fixable to a rotation shaft of a fan motor so that the impeller is rotatable by rotation of the rotation shaft by the fan motor to generate a suction force for suctioning air through an air passage;

a base portion extending from the boss portion and having a diameter that, when the boss portion is fixed to the rotation shaft so that the impeller is rotatable by rotation of the rotation shaft by the fan motor to generate the suction force for suctioning air through the air passage, increases from an intake side of the air passage toward a discharge side of the air passage; and

a wind cutting edge that has a proximal end at the base portion, and a protruding end that is opposite to the proximal end, is behind the proximal end in a rotation direction of the impeller, and, when the boss portion is fixed to the rotation shaft so that the impeller is rotatable by rotation of the rotation shaft by the fan motor to generate the suction force for suctioning air through the air passage, is closer to the intake side of the air passage than the proximal end is to the intake side of the air passage, and

11. The impeller of claim 10, wherein

the wind cutting edge has a swept-back angle with respect to a reference line passing through a center of rotation of the impeller and the proximal end in a radial direction in a range of 15° to 19°.

12. The impeller of claim 10, wherein

13. The impeller of claim 10, wherein

the plurality of blades are on an upper surface of the base portion which, when the boss portion is fixed to the rotation shaft so that the impeller is rotatable by rotation of the rotation shaft by the fan motor to generate the suction force for suctioning air through the air passage, is sloped toward the discharge side of the air passage while extending toward a circumferential side of the impeller in a radial direction from the boss portion.

14. The impeller of claim 13, wherein

15. The impeller of claim 10, wherein