Patent Application
20240392799
The present disclosure relates to an impeller, and more particularly to an impeller and a cleaner which employs the same.
There are small, lightweight stick-type cleaners that operate wirelessly and are easy to handle. Such 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 about 50,000 rpm or more while delivering a suitable amount of torque has been used as a motor for rotating the impeller.
Because stick-type cleaners also require a high suction force equal to or higher than that of conventional canister-type cleaners, high-speed rotation of motors is progressing, and recently, motors that rotate at ultra-high speeds exceeding about 100,000 rpm have been realized. Accordingly, the impellers are also required to be high performance impellers.
According to an aspect of the present disclosure, a cleaner includes a main body portion including a filtration chamber and an exhaust chamber, and a dust case connected to the main body portion. An impeller is included and is disposed in the main body portion, where the impeller generates a suction force to suck air from the dust case into the main body portion through an air passage, while being rotated by a motor. The impeller includes a boss portion to which a shaft of the motor is fixed, a base portion that slopes downward from an upstream side of the air passage toward a downstream side of the air passage based on the boss portion, and has a diameter that gradually increases from the upstream side of the air passage toward the downstream side of the air passage. The impeller further includes a plurality of blades disposed radially on the base portion to generate a suction force within the air passage, where each of the plurality of blades has a pressure surface which is a front surface of each of the plurality of blades with respect to a rotational direction of the impeller. The pressure surface is curved concavely toward the rotational direction.
According to an aspect of the present disclosure, an impeller is installed in an air passage to generate a suction force while being rotated by a motor. The impeller includes a boss portion to which a shaft of the motor is fixed, a base portion that slopes downward from an upstream side of the air passage toward a downstream side of the air passage based on the boss portion, and has a diameter that gradually increases from the upstream side of the air passage toward the downstream side of the air passage and a plurality of blades disposed radially on the base portion to generate a suction force within the air passage. Each of the plurality of blades has a pressure surface, which is a front surface of each of the plurality of blades with respect to a rotational direction of the impeller, where the pressure surface is curved concavely toward the rotational direction.
It should be understood that various embodiments of the disclosure and terms used herein are not intended to limit the technical features described herein to particular embodiments and that the disclosure includes various modifications, equivalents, or substitutions of the embodiments of the disclosure.
With regard to the description of the drawings, like reference numerals may be used to represent like or related elements.
A singular form of a noun corresponding to an item may include one or a plurality of the items unless the context clearly indicates otherwise.
As used herein, each of the phrases such as “A or B,” “at least one of A and B, “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C” may include any one of the items listed together in a corresponding one of the phrases, or all possible combinations thereof.
The term “and/or” includes any combination of a plurality of associated elements listed, or any one of the plurality of associated listed elements.
Terms such as “first,” “second,” etc. may be used simply to distinguish an element from other elements and do not limit the elements in any other respect (e.g., importance or order).
It will be understood that when an element (e.g., a first element) is referred to, with or without the term “functionally” or “communicatively”, as being “coupled” or “connected” to another element (e.g., a second element), the element may be coupled to the other element directly (e.g., in a wired manner), wirelessly, or via a third element.
Moreover, terms such as “comprise,” “include,” or “have” are intended to specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.
It will also be understood that when an element is referred to as being “connected,” “coupled,” “supported,” or “in contact” with another element, this includes not only when the elements are directly connected, coupled, supported, or in contact, but also when they are indirectly connected, coupled, supported, or in contact via a third element.
It will also be understood that when an element is referred to as being located “on” another element, the element may be directly disposed on the other element, or intervening elements may also be present therebetween.
Also, sizes of elements in the drawings may be exaggerated or reduced for convenience of explanation. For example, because sizes and thicknesses of elements in the drawings are arbitrarily illustrated for convenience of explanation, the invention is not limited thereto. That is, for convenience of explanation, the size, thickness, and ratio of elements illustrated in the drawings may be exaggerated and/or simplified for clarity. Accordingly, spatially relative terms such as “below,” “under,” “lower,” “above,” “upper,” etc. are terms used herein to easily describe a relationship of one element or feature.
Terms used to describe space, direction, etc. in the present specification are terms for describing the space and direction illustrated in the drawings, but may be understood as terms for describing various other directions or various viewpoints. For example, when a device or element illustrated in the drawings is turned over, the device or element described as “below” may be interpreted in a different direction (e.g., rotated 90 degrees, an opposite direction, etc.). For example, when a device or element illustrated in the drawings is turned over, the device or element described as “on” may be interpreted as a different direction (e.g., rotated 90 degrees, an opposite direction, etc.). Accordingly, “below” and “on” may include both upward and downward directions. In addition, a device or element may be oriented differently from the drawings, and the description of space or direction described herein may be variously interpreted.
The order of processes or the order of methods understood in the description of processes, manufacturing methods, etc. in the present specification may be different from the stated order. For example, two consecutively described processes or methods may be performed simultaneously or substantially simultaneously or may be performed in the order opposite to the described order.
The x-axis, the y-axis, and the z-axis are not limited to three axes of the rectangular coordinate system and may be interpreted in a broader sense. For example, the x-axis, the y-axis, and the z-axis may be perpendicular to one another or may represent different directions that are not perpendicular to one another.
It will be understood that the terms “first,” “second,” “third,” etc. may be used herein to describe specific elements, and the terms “first,” “second,” “third,” etc. may be only used to distinguish one element from another.
The terms as used in the present specification are only used to describe specific embodiments and are not intended to limit the invention. The singular forms “a” and “an” as used herein are intended to include the plural forms as well unless the context clearly indicates otherwise.
For example, the expressions “mixing,” “mixture,” “mix,” “have,” etc. specify the presence of the stated features, integers, steps, operations, elements, and/or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups.
For example, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, the expression “A and/or B” indicates only A, only B, or both A and B. The expressions such as “at least one” may be used to indicate one or more elements among a plurality of elements. For example, the expressions “at least one of a, b, or c” and “at least one selected from a, b, and c” may indicate “only a,” “only b,” “only c,” “a and b,” “b and c,” “a and c,” or “all of a, b, and c.”
For example, “substantially,” “about,” and terms similar thereto are used as terms of approximation rather than terms of degree, and may be terms used to describe inherent fluctuations in measured or calculated values that may be recognized by those of ordinary skill in the art. For example, terms such as “be able to,” “may,” etc. may be used to mean “one or more embodiments disclosed herein.”
For example, in the present specification, the expression “one layer has the same layer structure as another layer” may mean that a plurality of layers included in one layer may be included in the other layer in the same order. For example, a plurality of layers included in one layer and a plurality of layers included in another layer may each include the same material and may be formed in the same order.
In an embodiment, a cleaner, for example, a cordless stick type cleaner, is provided with a blower. The blower includes an impeller and a motor that rotates the impeller. In order to realize high suction power, motors are becoming smaller and faster, and, along with this, impellers are required to be smaller and have a higher performance capability. The present disclosure provides a high-performance impeller suitable for high-speed rotation or ultra-high-speed rotation, and a cleaner which employs the high-performance impeller. The present disclosure also provides a small impeller which is capable of providing a high suction force, and a cleaner which employs the small impeller. The present disclosure provides a small impeller suitable for stick type cleaners and having an improved suction force, and a cleaner which employs the small impeller. However, the technical problems solved by the disclosure are not limited to the above-mentioned technical problems, and solutions to other technical problems not mentioned will be clearly understood by a person skilled in the art to which the disclosure pertains.
In an embodiment, an impeller and a cleaner which employs the same, will now be described more fully with reference to the accompanying drawings so that the embodiments may be easily performed by one of ordinary skill in the art to which the present disclosure pertains. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted for the simplicity of explanation, and like reference numbers refer to like elements throughout.
In an embodiment, an impeller 20 is mounted in the cleaner 1. The cleaner 1 may include a main body 3 including a filtration chamber 31 and an exhaust chamber 30, and a dust case 4 connected to the main body 3. The cleaner 1, according to an embodiment, may further include a pipe 2 and a handle 5, wherein the handle 5 is a part that a user holds, and is connected to the main body 3. A user is capable of using the cleaner 1 while holding the handle 5 with one hand.
In an embodiment, the pipe 2 may be an elongated, cylindrical member. A head 2a of the cleaner 1 for suctioning dust is mounted on an end portion of the pipe 2. The main body 3 and the handle 5 may be integrated with the other end portion of the pipe 2. A blower 10 is accommodated within the main body 3 and a battery 6 may be accommodated in the handle 5. The battery 6 may be a rechargeable secondary battery, and will supply electrical energy to the blower 10. The electric energy supplied from the battery may drive a motor 13, which will be described later, which is installed in the blower 10 to rotate the impeller 20.
The dust case 4 is installed below the main body 3 and may be detachable from the main body 3. When the blower 10 is driven, a strong suction force is generated in a head 2a and dust suctioned through the head 2a is collected in the dust case 4 through the pipe 2.
In an embodiment and referring to a portion of
In an embodiment, the shroud 11 covers the outside of the air passage 50. When the impeller 20 rotates, the air in the air passage 50 flows as indicated by arrow Y1 in
In an embodiment and referring to
From a functional point of view of the air passage 50, the shroud 11 may include a moving blade portion 11P, a suction portion 11V extending upstream from the rotor portion 11P, and a static blade portion 11E extending downstream from the moving blade portion 11P. The moving blade portion 11P may include a portion extending from the small diameter portion 11c to the relay area 11d of the downstream large-diameter portion 11b. Accordingly, the moving blade portion 11P has a shape whose inner diameter gradually increases from the upstream side to the downstream side. The impeller 20 is accommodated in the moving blade portion 11P such that each of the plurality of blades 23 faces the inner surface of the moving blade portion 11P with a tip clearance disposed therebetween.
In an embodiment, the suction portion 11V may include the upstream large-diameter portion 11a, and the relay area 11d connecting the upstream large-diameter portion 11a to the small-diameter portion 11c. Therefore, the inner diameter of the suction portion 11V gradually becomes smaller from the upstream side of the air passage 50 to the downstream side of the air passage 50, and the air inside of the suction portion 11V flows from outside the suction portion 11V to inside the suction portion 11V in a diameter direction along an inner surface of the suction portion 11V. The motor 13 is accommodated in the suction portion 11V. The static blade portion 11E may include the downstream large-diameter portion 11b. The diffuser 15 is accommodated in the static blade portion 11E.
In an embodiment, the motor 13 may include a shaft 13a, a rotor 13b, and a stator 13c. A motor case 12 is inserted into and accommodated in the upstream large-diameter portion 11a. At the center of the motor case 12, the shaft 13a is rotatably supported by a bearing 12a. A rotor 13b is fixed to a middle portion of the shaft 13a and the stator 13c is assembled to the motor case 12 such that the stator 13c is positioned around the rotor 13b with a gap disposed therebetween. Accordingly, the motor 13 including the shaft 13a, the rotor 13b, and the stator 13c is disposed at a central portion of the suction portion 11V and is integrated with the motor case 12. The rotation axis A of the motor 13 coincides with respective centers of the motor case 12 and the shroud 11.
One end portion of the shaft 13a protrudes from the motor case 12. The motor case 12 is inserted into and accommodated in the shroud 11 such that the protruding end portion of the shaft 13a faces downstream. Accordingly, the air passage 50 described above is formed between the motor 13 and the inner surface of the suction portion 11V of the shroud 11, that is, the inner surface of the upstream large-diameter portion 11a.
In an embodiment, a controller 14 for controlling the motor 13 may be installed on the upstream side of the motor case 12. The controller 14 may include a printed circuit board on which an electronic component such as a motor driving IC is mounted. For example, in an embodiment, the motor 13 is located upstream of the impeller 20 within the air passage 50, and the controller 14 is disposed upstream of the motor 13 within the air passage 50. The controller 14 may be arranged so that a printed circuit board faces the air passage 50. The controller 14 controls the driving of the motor 13 according to a signal for manipulating the cleaner 1.
The motor 13 may be small. For example, according to an embodiment, the stator 13 may be the size of the palm of an average sized hand by having an outer diameter of about 40 mm and a height of about 70 mm. Accordingly, the motor 13 may also be very light in weight.
In an embodiment, the motor 13 may have a structure capable of obtaining a high output with a high efficiency, so as to obtain sufficient performance that is used in the cleaner 1 by using the power of the battery 6. For example, the motor 13, according to an embodiment, may have a structure capable of obtaining suction power of about 250 W or more by the impeller 20 being driven at a high speed rotation of about 50,000 rpm or more, at an ultra-high speed rotation of about 100,000 rpm or more, and even at an ultra-high speed rotation of about 130,000 rpm or more, with consumption power of about 600 W.
In an embodiment, the diffuser 15 may be accommodated in the static blade portion 11E and may include an upper diffuser 15U and a lower diffuser 15D, and three or more diffusers 15 may be provided. Each of the upper diffuser 15U and the lower diffuser 15D may be a cylindrical member, and a plurality of vanes 15a disposed obliquely with respect to an axial direction (for example, the rotation axis A) are formed on the outer circumferential surface of each of the upper diffuser 15U and the lower diffuser 15D. An inclination angle of the vanes 15a in the lower diffuser 15D may be smaller than that of the vanes 15a in the upper diffuser 15U, where each of the upper diffuser 15U and the lower diffuser 15D may be fixed to an inner circumferential surface of the downstream large-diameter portion 11b.
As described above, the impeller 20 is disposed on the moving blade portion 11P of the shroud 11 forming the air passage 50. In an embodiment, the impeller 20 includes a boss portion 21 fixed to the shaft 13a of the motor 13 that is aligned with the rotation axis A, a base portion 22 extending around the boss portion 21 and having an annular shape, and a plurality of blades 23. The plurality of blades 23 are arranged radially on the base portion 22 and generate a suction force within the air passage 50.
During an operation of the cleaner 1, the impeller 20 is rotated by the motor 13 at high speed in a certain direction, and, in an embodiment, in a counterclockwise direction (see
The air entering the shroud 11 is sucked into the moving blade portion 11P while cooling the controller 14 or the motor 13 in an air-cooling manner. Because the amount of heat generated by the controller 14 and the motor 13 increases with increased speed or with high suction power, it is important to cool them. In the blower 10, according to an embodiment, because the motor 13 is disposed in the upstream side of the moving blade portion 11P, heat exchange between air of relatively low temperature, which is the same as that of the outside air, and the controller 14 and the motor 13 is possible. Accordingly, the cooling property of the controller 14 or the motor 13 is excellent.
In an embodiment, the air is concentrated within the suction part 11V while being curved from the outer circumference of the suction portion 11V and bent to the center thereof to flow to the moving blade portion 11P. In detail, the air flows in an axial direction along the inner surface of the upstream large-diameter portion 11a and a lateral portion of the motor 13, and then flows from an outer circumference side (outside in the diameter direction) toward a center side (inside in the diameter direction) along an inner surface of the relay area 11d which is connected to the upstream large-diameter portion 11a and the lateral portion of the motor 13 and is directed toward the moving blade portion 11P. Therefore, air flow may be in efficient contact with the controller 14 or the motor 13, and thus heat exchange with the controller 14 or the motor 13 is easy. Accordingly, the cooling property of the controller 14 or the motor 13 is further excellent.
In an embodiment, air entering the moving blade portion 11P passes through a space between an inner surface of the moving blade portion 11P and the base portion 22 of the impeller 20 (specifically, between the blades 23), and enters the static blade portion 11E. The air entering the static blade portion 11E passes through a space between an inner surface of the static blade portion 11E and an outer circumferential surface of the diffuser 15 (specifically, between the vanes 15a) and enters the exhaust chamber 30.
The air enters the exhaust chamber 30 while being rectified in the axial direction by passing through the diffuser 15. The air entering the exhaust chamber 30 flows out into the filtration chamber 31 through the inner exhaust holes 30a and is exhausted out of the main body 3 through the outer exhaust holes 33.
The impeller 20 is also small, like the motor 13. For example, an outer diameter of the impeller 20 may be about 10 mm to about 50 mm. According to an embodiment, the impeller 20 may have a size (so-called, a palm size) corresponding to an outer diameter of about 40 mm. When the motor 13 is driven, the impeller 20 rotates counterclockwise when viewed from the top, as indicated by arrow Yr in
The impeller 20 includes the boss portion 21 fixed to the shaft 13a with its protruding end side facing toward the upstream side of the air passage 50, and an annular base portion 22 having an annular shape that slopes downward and has a gradually larger diameter in a direction from the protruding end side of the boss portion 21 to a proximal end side thereof, that is, in a direction from the upstream side of the air passage 50 to the downstream side of the air passage 50. Accordingly, an inclined surface 22a is formed on the upper surface of the base portion 22, the inclined surface 22a sloping downwards and having a gradually increasing diameter in a direction from the protruding end side of the boss portion 21 to the proximal end side thereof, that is, from the upstream side of the air passage 50 to the downstream side thereof. The inclined surface 22a is curved gently upward to be concave in a direction from an inner circumference side to an outer circumference side, where an inclination angle of the inclined surface 22a may be about 30°, and may range from about 20° to about 40°.
In an embodiment, each blade 23, which is in a thin plate shape, protrudes from the inclined surface 22a of the base portion 22 and extends so as to gradually shift backward with respect to the rotational direction Yr (i.e., in a direction opposite to the rotational direction Yr) in a radial direction from the lateral side of the boss portion 21. That is, each blade 23 is inclined such that its outer circumferential side is located behind its central side in the rotational direction Yr. When the impeller 20 rotates, air flows from inside to outside in the diameter direction and slips out of the impeller 20 through gaps between the plurality of blades 23 in a direction that is inclined with respect to the rotation axis A. Thus, a suction force is generated.
In an embodiment, the impeller 20 includes nine blades 23 arranged at equidistant intervals in a circumferential direction. Each blade 23 may be provided with two edges 23a and 23b spaced apart from each other in the diameter direction, and two edges 24k and 24t spaced apart from each other in a vertical direction, that is, in the direction of the rotation axis A. Each blade 23 has an outer appearance of a strip type in which one edge 23a in a radial direction is longer and the other edge 23b is shorter. The longer edge (wind-cutting edge) 23a in the radial direction is positioned on a center side of the base portion 22, and the shorter edge (wind-sending edge) 23b is positioned on an outer circumferential side of the base portion 22. The wind-cutting edge 23a includes a proximal end 23ak located on the side of the base portion 22 and a protruding end 23at spaced apart from the base portion 22. The proximal end 23ak is an end connected to the inclined surface 22a of the base portion 22, and the protruding end 23at is an end extending from the proximal end 23ak and being spaced apart from the inclined surface 22a of the base portion 22. The wind-sending edge 23b includes a proximal end 23bk on the side of the base portion 22 and a protruding end 23bt spaced apart from the base portion 22. The proximal end 23bk is an end connected to the inclined surface 22a of the base portion 22, and the protruding end 23bt is an end extending from the proximal end 23bk and being spaced apart from the inclined surface 22a of the base portion 22. Each blade 23 includes a wing root edge 24k and a wing tip edge 24t. The wing root edge 24k is an edge connecting the proximal end 23ak of the wind-cutting edge 23a to the proximal end 23bk of the wind-sending edge 23b, and is an edge connected to an upper surface of the base portion 22, that is, the inclined surface 22a. The wing tip edge 24t is an edge connecting the protruding end 23at of the wind-cutting edge 23a to the protruding end 23bt of the wind-sending edge 23b, and is an edge spaced upward from the upper surface of the base portion 22, that is, the inclined surface 22a. As shown in a lower drawing of
In an embodiment, each blade 23 may have a shape twisted from the wind-cutting edge 23a toward the wind-sending edge 23b. The wind-cutting edge 23a is inclined while being twisted in the rotation direction Yr in a direction from the proximal end 23ak to the protruding end 23at, and the wind-sending edge 23b is inclined while being twisted in an opposite direction of the rotation direction Yr from the proximal end 23bk to the protruding end 23bt. The wind-cutting edge 23a extends, as shown in
In each blade 23, the protruding end 23at of the wind-cutting edge 23a is positioned behind the proximal end 23ak of the wind-cutting edge 23a based on the rotation direction Yr. For convenience, this shape of the blade 23 is referred to as a swept-back wing shape. Due to the swept-back wing shape, air resistance of the blade 23 is reduced, so that an impeller 20 that is efficiently advantageous for high-speed rotation may be realized. Referring to the upper drawing of
In the case of the impeller 20, according to an embodiment, the protruding end 23at of the wind-cutting edge 23a is positioned at a higher location (the upstream side of the air passage 50) than the proximal end 23ak of the wind-cutting edge 23a. In detail, referring to the lower drawing of
The blade 23 may have a shape that corresponds to high-speed rotation or ultra-high-speed rotation. According to an embodiment, as schematically shown by a broken line in
In an embodiment, the cross-sectional view d1 shows a cross-sectional shape passing through a proximal end 23ak of a wind-cutting edge 23a of a first blade 23-1. The cross-sectional view d3 shows a cross-sectional shape passing through a protruding end 23at of the wind-cutting edge 23a of the first blade 23-1. The cross-sectional view d6 shows a cross-sectional shape passing through a proximal end 23bk of a wind-sending edge 23b of a second blade 23-2. A cross-section position of the first blade 23-1 in the cross-sectional view d6 roughly corresponds to a cross-sectional position of the second blade 23-2 in the cross-sectional view d3.
In an embodiment, the cross-sectional views d1 through d6 also show cross-sections from the middle of the first blade 23-1 to the center side thereof in an approximately lengthwise direction of the first blade 23-1. The cross-sectional views d3 through d6 show cross-sections from the middle of the second blade 23-2 to the outer circumferential side thereof in a lengthwise direction of the second blade 23-2. Because angular positions of the first blade 23-1 and the second blade 23-2 with respect to the rotation axis A are different, cross-sectional shapes of the second blade 23-2 shown in the cross-sectional views d3 through d6 are not completely the same as cross-sectional shapes at corresponding positions of the first blade 23-1. However, the curved shape of the axial cross-section of the pressure surface 25 over the entire lengthwise direction of the blade 23 may be understood from the shapes of the first blade 23-1 shown in the cross-sectional views d1 through d6 and the cross-sectional shapes of the second blade 23-2 shown in the cross-sectional views d3 through d6.
In an embodiment, the cross-sectional shapes of the blade 23 shown in the cross-sectional views d1 through d6 are strictly different from the cross-sectional shape in the span direction (width direction of the blade 23) of the blade 23 shown by a broken line in
However, in the case of the cross-section in the span direction, a wind-cutting edge 23a located on the center side of the blade 23 extends in a substantially straight line, as shown in the cross-sectional view d1. Therefore, in the case of the cross-section in the span direction, the wind-cutting edge 23a and its nearby portion (suction side end 26) are not curved. Therefore, in the case of the cross-section in the span direction, the curved cross-sectional shape of the pressure surface 25 is formed in an area excluding the suction side end 26 of the blade 23.
Generally, the blade 23 has a flat shape, and the cross section of the pressure surface 25 is straight. A fluid analysis was performed on the shape of the blade 23 to understand the blade under high-speed or ultra-high-speed rotation.
As a result of performing fluid analysis on the impeller 20C, according to the comparative example, and the impeller 20, according to the present embodiment, it is confirmed that, by forming the pressure surface 25 of the blade 23 into the above-described curved shape, according to the present embodiment, a flow velocity difference in the air within the moving blade portion 11P is reduced during high-speed rotation and ultra-high-speed rotation, thereby reducing friction loss and mixing loss and improving energy efficiency. Energy efficiency may be defined as a value obtained by dividing the suction power by the amount of power supplied.
As shown in
On the contrary, in the impeller 20, according to an embodiment, a flow velocity near the wing root edge 24t is relatively low, and a flow velocity near the wing tip edge 24t is relatively high, compared with the impeller 20C, according to the comparative example. Therefore, compared to the impeller 20C, according to the comparative example, it was found that the flow velocity difference along the span direction of the blade 23 was reduced. That is, both a local high-speed region near the wing root edge 24k and a low-speed region near the wing tip edge 24t may be reduced, so that the flow velocity is uniformized in the span direction. Accordingly, the flow velocity of air discharged from the moving blade portion 11P is stabilized. As a result, friction loss and mixing loss may be reduced, thereby improving energy efficiency.
In addition, in the impeller 20, according to an embodiment, a wake phenomenon may be suppressed.
In the comparative example, an air flow leading to the downstream side of the impeller 20C, that is, a wake, occurs at the outlet portion of the moving blade portion 11P. Because the wake serves as air resistance, it is necessary to suppress this wake in order to improve energy efficiency. On the contrary, in an embodiment, a wake like the comparative example hardly occurs, and the wake is suppressed compared to the comparative example. As a result, it is confirmed that, when the impeller 20, according to an embodiment, is employed, a suction force increases and energy efficiency is improved, compared to a case where the impeller 20C, according to a comparative example, is employed.
Thus, the curved shape of the pressure surface 25 of the impeller 20 may be optimized to minimize leakage vortices. According to an embodiment, a length of the blade 23 may be expressed as a percentage in which an end of the blade 23 located near (on a suction side of) the boss portion 21 in the center of the impeller 20 is set to about 0% and an end of the blade 23 located on the outside (an extraction side) in the diameter direction of the impeller 20 is set to about 100%. For example, in
By designing the degree of curvature of the pressure surface 25 in this way, a flow velocity near the wing tip edge 24t of the blade 23, shown in
Thus, a cleaner 1 and an impeller 20 employed therein are not limited to the above-described embodiments. For example, the cleaner 1 is not limited to a stick type cleaner 1, and may be a robot cleaner or an upright cleaner. In addition, the shape of the inclined surface 22a of the base portion 22 is not limited to a downwardly curved shape, and may be an upwardly curved shape or may be a shape inclined at a certain angle without being curved.
According to an embodiment, a cleaner 1 includes a main body 3 including a filtration chamber 31 and an exhaust chamber 30, a dust case 4 connected to the main body 3, an impeller 20 disposed in the main body 3 to generate a suction force to suck air from the 4 into the main body 3 through an air passage 50, while rotating and a motor 13 configured to rotate the impeller 20. The impeller 20 includes a boss portion 21 to which a shaft 13a of the motor 13 is fixed, a base portion 22 that slopes downward from an upstream side of the air passage 50 toward a downstream side of the air passage 50, based on the boss portion 21 and has a diameter that gradually increases from the upstream side of the air passage 50 toward the downstream side of the air passage 50 and a plurality of blades 23 disposed radially on the base portion 22 to generate a suction force in the air passage 50. Each of the plurality of blades 23 has a pressure surface 25, which is a front surface of each of the plurality of blades 23 with respect to a rotational direction (Yr) of the impeller 20. The pressure surface 25 is curved concavely toward the rotational direction (Yr).
By forming the pressure surface 25 of the blade 23 into the above-described curved shape, a flow velocity difference in the air flow within a moving blade portion 11P is reduced during high-speed rotation and ultra-high-speed rotation, and thus leakage vortices may be suppressed. This leads to reductions in friction loss and mixing loss in air flow. Therefore, energy efficiency may be improved.
According to an embodiment, a length of the blade 23 is expressed as a percentage, so that, when an end of the blade 23 disposed adjacent to the boss portion 21 is set to about 0% and an end of the blade 23 located on outside in the diameter direction is set to about 100%, a minimum radius of curvature of a cross-sectional shape of the pressure surface 25 may be minimum between the range of about 60% and about 95% of the lengthwise direction. Accordingly, the curved shape of the pressure surface 25 may be optimized. As a result, leakage vortices may be further suppressed, and thus friction loss and mixing loss may be further reduced. Therefore, energy efficiency may be further improved.
According to an embodiment, the base portion 22 may include an inclined surface 22a that slopes downward from the upstream side of the air passage 50 toward the downstream side of the air passage 50 and has a diameter that gradually increases from the upstream side of the air passage 50 toward the downstream side of the air passage 50. The plurality of blades 23 may protrude from the inclined surface 22a, and may extend to be shifted in a backward direction with respect to the rotational direction (Yr) in a radial direction from the boss portion 21. When the impeller 20 rotates, air within the air passage 50 flows from inside to outside in the diameter direction and slips out of the impeller 20 through gaps between the plurality of blades 23 in a direction inclined with respect to the rotation axis A, and thus a suction force may be generated on an upstream side of the air passage 50.
According to an embodiment, each of the plurality of blades 23 may include a wind-cutting edge 23a disposed close to the boss portion 21. The wind-cutting edge 23a may include a proximal end on the side of the base portion 22 and a protruding end spaced apart from the base portion 22. Each of the plurality of blades 23 may have a swept-back wing shape in which the protruding end of the wind-cutting edge 23a is located behind the proximal end of the wind-cutting edge 23a with respect to the rotation direction Yr. According to the blade 23 having the swept-back wing shape, air resistance is reduced, and thus the impeller 20 is efficiently advantageous for high-speed or ultra-high-speed rotation.
According to an embodiment, a swept-back angle of the wind-cutting edge 23a may be in the range of about 30° to about 50°. Accordingly, the swept-back wing shape may be optimized, and thus air resistance may be effectively reduced.
According to an embodiment, the wind-cutting edge 23a may be inclined to protrude toward an upstream side of the air passage 50 in a direction from the proximal end to the protruding end. Thus, a blade load at an end located on an air inlet side of the blade 23 may be reduced, and leakage flow may also be reduced. According to an embodiment, an inclination angle of the wind-cutting edge 23a may be in the range of about 10° to about 30°.
According to an embodiment, the cleaner 1 may include a shroud 11 configured to form the air passage 50. The shroud 11 may include a moving blade portion 11P with an inner diameter gradually increasing in a direction from an upstream side to a downstream side, in which the impeller 20 is accommodated such that each of the plurality of blades 23 faces an inner surface of the moving blade portion 11P with a tip clearance disposed therebetween, a suction portion 11V extending from the moving blade portion 11P to the upstream side and a static blade portion 11E extending from the moving blade portion 11P to the downstream side. The motor 13 may be disposed in the suction portion 11V.
Because the amount of heat generated by the motor 13 increases as speed increases, it is important to cool the motor 13. Because the motor 13 is disposed in a suction section 11V, that is, on the upstream side of the moving blade portion 11P, heat exchange between air with a relatively low temperature which is the same as that of the outside air, and the motor 13 is possible. Therefore, the motor 13 may be effectively cooled.
According to an embodiment, an inner diameter of the suction portion 11V may gradually become smaller from the upstream side of the air passage 50 to the downstream side of the air passage 50 so that the air flows along the inner surface of the suction portion 11V from outside to inside in a diameter direction within the suction portion 11V. Accordingly, the air flowing in the suction portion 11V flows from outside to inside in the diameter direction along the inner surface of the suction portion 11V, and thus the air flow may efficiently contact the motor 13, making it easy to exchange heat between the air and the motor 13, thereby improving cooling performance.
According to an embodiment, the cleaner 1 may further include a controller 14 configured to control the motor 13. In the air passage 50, the motor 13 may be located on an upstream side of the impeller 20. The controller 14 may be located on an upstream side of the motor 13. Accordingly, the motor 13 and the controller 14 may be effectively cooled by external air.
According to an embodiment, an impeller 20 installed in an air passage 50 to generate a suction force while being rotated by a motor 13 includes a boss portion 21 to which a shaft 13a of the motor 13 is fixed, a base portion 22 that slopes downward from an upstream side of the air passage 50 toward a downstream side of the air passage 50, based on the boss portion 21, and has a diameter that gradually increases from the upstream side of the air passage 50 toward the downstream side of the air passage 50 and a plurality of blades 23 disposed radially on the base portion 22 to generate a suction force in the air passage 50. Each of the plurality of blades 23 has a pressure surface 25, which is a front surface of each of the plurality of blades 23 with respect to a rotational direction Yr of the impeller 20. The pressure surface 25 is curved concavely toward the rotational direction Yr.
According to an embodiment, a length of the blade 23 is expressed as a percentage, so that, when an end of the blade 23 disposed adjacent to the boss portion 21 is set to about 0% and an end of the blade 23 located on outside in the diameter direction 20 is set to about 100%, a minimum radius of curvature of a cross-sectional shape of the pressure surface 25 may be minimum between a range of about 60% and about 95% of the lengthwise direction.
According to an embodiment, the base portion 22 may include an inclined surface 22a that slopes downward from the upstream side of the air passage 50 toward the downstream side of the air passage 50 and has a diameter that gradually increases. The plurality of blades 23 may protrude from the inclined surface 22a, and may extend to be shifted backward with respect to the rotational direction Yr in a radial direction from the boss portion 21.
According to an embodiment, each of the plurality of blades 23 may include a wind-cutting edge 23a disposed close to the boss portion 21. The wind-cutting edge 23a may include a proximal end on the side of the base portion 22 and a protruding end spaced apart from the base portion 22. Each of the plurality of blades 23 may have a swept-back wing shape in which the protruding end of the wind-cutting edge 23a is located behind the proximal end of the wind-cutting edge 23a with respect to the rotation direction Yr.
According to an embodiment, the wind-cutting edge 23a may be inclined to protrude toward an upstream side of the air passage 50 in a direction from the proximal end to the protruding end.
As described above, an impeller 20 and a cleaner employing the same may, according to an embodiment, provide an improved suction force, compared to a conventional impeller and a cleaner employing the same. Therefore, by employing the impeller 20, according to an embodiment, in a stick-type cleaner 1, etc., a high-performance cleaner may be implemented.
The technical effects to be achieved in this document are not limited to the above-mentioned technical effects, and other technical effects not mentioned will be clearly understood by a person skilled in the art to which the present disclosure pertains.
As described above, although the cleaner and the impeller according to the present disclosure have been described using limited embodiments and drawings, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit thereof. It should be understood that embodiments described herein should be considered in a descriptive sense and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Moreover, the embodiments or parts of the embodiments may be combined in whole or in part without departing from the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-074202 | Apr 2023 | JP | national |
This application claims priority to PCT International Patent Application No. PCT/KR2024/003642, filed on Mar. 22, 2024, and Japanese Patent Application No. 2023-074202, filed on Apr. 28, 2023, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in their entirety are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2024/003642 | Mar 2024 | WO |
| Child | 18766852 | US |
