Patent Application
20200378398
The present disclosure relates to an impeller, a blower, and a vacuum cleaner.
As a conventional impeller, one that is provided in an electric blower is known, in which the impeller specific speed Ns (min−1, m3/min, m reference)=rotational speed N×√(flow rate Q)÷pump head H ¾=less than 1200, and the inlet area of the impeller is larger than the outlet area of the impeller.
In the conventional impeller, the above configuration allows efficiency to be improved by converting the kinetic energy of the fluid into static pressure at the outlet of the impeller. However, the conventional impeller is required to further improve the blowing efficiency.
An impeller according to an example embodiment of the present disclosure is rotatable about a vertically extending central axis. The impeller includes a base portion extending radially outward as it extends downward, a plurality of first blades circumferentially arrayed on the upper surface of the base portion and extending on one side in the circumferential direction as it extends upward, and a plurality of second blades between the circumferential direction of the circumferentially adjacent first blades and extending on one side in the circumferential direction as it extends upward. The radial outer end of the second blade is on one side in the circumferential direction relative to the middle in the circumferential direction of the radial outer end of the circumferentially adjacent first blade.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
Hereinafter, example embodiments of the present disclosure will be described with reference to the drawings. It is to be noted that in this description, the direction in which a central axis J of a blower B extends is referred to as “vertical” or “axial”, the direction orthogonal to the central axis J of the blower B is referred to as “radial”, and the direction along an arc centered on the central axis J of the blower B is referred to as “circumferential”. However, the above-mentioned “vertical” does not limit the direction of the blower B when it is actually incorporated into an apparatus. Furthermore, in the drawings, for the sake of convenience, the contents of the drawings such as dimensions may be different from the actual structure. In addition, in the drawings, hatching may be omitted for the sake of convenience. It is to be noted that in this description, the words such as vertical, axial, radial, and circumferential do not strictly indicate only these directions but also include directions slightly inclined from these directions.
In addition, in the present description, the shape and positional relationship of each part of a vacuum cleaner A will be described with the direction of approaching a floor surface F being “downward” and the direction of departing from the floor surface F being “upward”. It is to be noted that these directions are names used merely for explanation, and do not limit the actual positional relationships and directions.
The vacuum cleaner A according to an example embodiment of the present disclosure will be described.
An air passage (not shown) connecting the intake portion 103 and the exhaust portion 104 is formed in the chassis 102. A dust collecting portion (not shown), a filter (not shown), and the blower B are arranged in order from the upstream side toward the downstream side in the air passage. The blower B has an impeller 2 described later. Dust contained in gas flowing in the air passage is captured by the filter and collected in a dust collecting portion formed in a container shape. The dust collecting portion and the filter are configured removably to the chassis 102.
A grip portion 105 and an operation portion 106 are provided on the upper portion of the chassis 102. The user can move the vacuum cleaner A by gripping the grip portion 105. The operation portion 106 has a plurality of buttons 106a, and performs operation setting of the vacuum cleaner A by the operation of the buttons 106a. For example, the operation of the buttons 106a gives the blower B instructions of starting driving, stopping driving, and changing the number of rotations. The downstream end (upper end of the figure) of a rod-shaped suction pipe 107 is connected to the intake portion 103. A suction nozzle 108 is removably attached to the suction pipe 107 at the upstream end of the suction pipe 107. Dust on the floor surface F is sucked into the suction pipe 107 through the suction nozzle 108. The vacuum cleaner A has the blower B described later. This can improve the blowing efficiency of the blower B mounted on the vacuum cleaner A.
As shown in
The motor 1 has a stator 11, a rotor 12, a motor housing 13, a bearing 14, and a substrate 15. The rotor 12 is rotatable about the vertically extending central axis J and radially faces the stator 11. The motor housing 13 surrounds at least a part of the stator 11 and the rotor 12.
The stator 11 has a stator core 111, an insulator 112, and a coil 113. The stator core 111 is made of a magnetic material and has an annular core back and a teeth portion extending radially inward from the core back. At least a part of the teeth portion is surrounded by the insulator 112. The coil 113 is formed by winding a conductive wire around the teeth portion via the insulator 112.
The rotor 12 has a shaft 121, a magnet 122, an upper spacer 123, and a lower spacer 124. The shaft 121 is arranged along the central axis J. The magnet 122 is fixed to the shaft 121 and radially faces the radial inner end of portion the teeth portion. The upper spacer 123 and the lower spacer 124 are fixed to the shaft 121, respectively. The upper surface of the magnet 122 is in contact with the lower surface of the upper spacer 123, and the lower surface of the magnet 122 is in contact with the upper surface of the lower spacer 124. The magnet 122 is fixed by being axially sandwiched by the upper spacer 123 and the lower spacer 124.
The motor housing 13 has an upper motor housing 131, a lower motor housing 132, and a fixing member 133. The lower motor housing 132 is arranged downward relative to the upper motor housing 131. The upper motor housing 131 and the lower motor housing 132 surround at least a part of the stator 11 and the rotor 12, respectively. The stator core 111, the upper motor housing 131, and the lower motor housing 132 are fixed by the fixing member 133. In the present embodiment, the fixing member 133 is a screw.
The bearing 14 includes an upper bearing 141 and a lower bearing 142. The upper bearing 141 and the lower bearing 142 are fixed to the upper motor housing 131 and the lower motor housing 132, respectively, and rotatably support the shaft 121 around the central axis J.
The substrate 15 is arranged downward relative to the stator core 111. An electronic component 151 is arranged on the upper surface of the substrate 15. The electronic component 151 is, for example, a capacitor, an FET, or the like. The substrate 15 is fixed to the lower motor housing 132 by a fixing member 152.
The impeller 2 has a base portion 21, a first blade 22, and a second blade 23. The impeller 2 is fixed to the shaft 121. A downward extending cylindrical hub 211 is arranged on the lower surface of the base portion 21. The hub 211 is provided with an upwardly recessed recess portion, and the upper end portion of the shaft 121 is fixed in a state of being inserted into the recess portion. Thus, the impeller 2 is rotatable about the central axis J integrally with the shaft 121. That is, the impeller 2 is rotatable about the vertically extending central axis J.
The housing 3 has an impeller cover 31, an outer housing 32, and an inner housing 33. The impeller cover 31 surrounds at least a part of the impeller 2 upward and radially outward. The center of the impeller cover 31 is provided with an axially opening intake port 311. The impeller cover 31 has a curved surface portion 312 extending radially outward as it extends downward, and a cylindrical portion 313 extending downward from the radial outer edge of the curved surface portion.
The outer housing 32 is an axially extending cylindrical portion. The upper end portion of the outer housing 32 is fixed to the cylindrical portion 313. The lower end portion of the outer housing 32 is fixed to the lower motor housing 132. The inner housing 33 is arranged radially inward of the outer housing 32. The inner housing 33 has a top plate portion 331 arranged downward of the base portion 21 and stretching in a direction intersecting with the central axis J, and a cylindrical portion 332 extending downward from the radial outer edge of the top plate portion. A flow path is formed in the radial direction between a radial inner surface of the outer housing 32 and a radial outer surface of the cylindrical portion 332.
The gas sucked into the impeller cover 31 from the intake port 311 is discharged downward and radially outward by the impeller 2, flows downward in the flow path between the outer housing 32 and the cylindrical portion 332, flows along the radial inner surface of the lower motor housing 132, and is then discharged to the external space of the blower B. The blower B has the impeller 2. This improves the blowing efficiency of the blower B.
Hereinafter, the structure of the impeller 2 will be described in detail with reference to
As shown in
As shown in
A radial outer edge 223 of the first blade 22 extends upward as it extends radially outward. This enlarges the area of the first blade 22, thereby improving the blowing efficiency. That is, the blowing efficiency is improved because the area of the pressure surface of the first blade 22 becomes larger as compared with a case where the radial outer edge extends upward along a direction parallel to the central axis J, for example. As shown in
As shown in
The plurality of second blades 23 are arranged in between the circumferential direction of the first blades 22 adjacent in the circumferential direction C. The plurality of second blades 23 extend on one side in a circumferential direction C as it extends upward. A radial inner edge 231 of the second blade 23 extends upward as it extends radially outward. This enlarges the area of the second blade 23, thereby improving the blowing efficiency. That is, the blowing efficiency is improved because the area of the pressure surface of the second blade 23 becomes larger than that in a case where the radial inner edge 231 extends radially outward along a plane orthogonal to the central axis J, for example.
In planar view, the radial inner edge 231 of the second blade 23 is arranged on one side in the circumferential direction C as it extends radially outward. In the present embodiment, the radial inner edge 231 is a line-segment-shaped portion extending in a direction inclined to one side of the circumferential direction C relative to the normal direction of the base portion 21. This results in an increase in the area of the second blade 23, thereby improving the blowing efficiency. That is, the blowing efficiency is improved because the area of the pressure surface of the second blade 23 becomes larger than that in a case where the radial inner edge 231 extends in the normal direction of the base portion 21, for example.
In planar view, a radial outer end 237 at the radial inner edge 231 of at least one of the second blades 23 is arranged on the imaginary line L. More specifically, the radial outer end 237 at the radial inner edge 231 of the second blade 23 adjacent to one side in the circumferential direction C of a certain first blade 22 is arranged on the imaginary line L connecting the central axis J and the radial inner edge 221 of the first blade 22. Due to this, the radial outer end 237 of the radial inner edge 231 is arranged on the imaginary line L that overlaps the radial inner edge 221 of the first blade 22, and hence gas smoothly flows on both the pressure surface side and the negative pressure side of the second blade 23, thereby improving the blowing efficiency. It is to be noted that in the present embodiment, the radial outer end 237 at the radial inner edge 231 of the second blade 23 adjacent to one side in the circumferential direction C of all the first blades 22 is arranged on the imaginary line L connecting the central axis J and the radial inner edge 221 of the first blade 22 arranged on the other side in the circumferential direction C of the respective second blades 23. In addition, in the present embodiment, the radial outer end 237 at the radial inner edge 231 is a portion identical to an upper end 232 of the second blade 23.
A radial outer edge 233 of the second blade 23 extends upward as it extends radially outward. This enlarges the area of the second blade 23, thereby improving the blowing efficiency. That is, the blowing efficiency is improved because the area of the pressure surface of the second blade 23 becomes larger than that in a case where the radial outer edge 233 extends upward along a direction parallel to the central axis J, for example. As shown in
As shown in
As shown in
In the present embodiment, the radial outer ends 224 of the first blade 22 are arranged at equal intervals in the circumferential direction C. In addition, the radial outer ends 234 of the second blade 23 are also arranged at equal intervals in the circumferential direction C. This improves the rotational balance of the impeller 2. This allows the impeller 2 to accurately rotate about the central axis J even in a case where the impeller 2 rotates at a high speed.
As shown in
In planar view, the curvatures of the first connection region 25 and the second connection region 26 are not constant. In addition, the curvature of the first connection region 25 is larger than the curvature of the second connection region 26. More specifically, in planar view, the minimum value of a radius R1 of curvature in the first connection region 25 of the base portion 21 and the surface of the other side in the circumferential direction C of the first blade 22 is smaller than the minimum value of a radius R2 of curvature in the second connection region 26 of the base portion 21 and the surface of the other side in the circumferential direction C of the second blade 23. This can suppress the gas flowing in the vicinity of the first connection region 25 and the second connection region 26 from being separated from the negative pressure surfaces of the first blade 22 and the second blade 23, thereby improving the blowing efficiency of the impeller 2.
As shown in
The present disclosure can be used in an impeller, for example. Furthermore, the impeller of the present disclosure can also be used in a blower or a vacuum cleaner. In addition, the present disclosure can be used in other electrical apparatuses.
Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.
While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-079489 | Apr 2020 | JP | national |
The present application claims priority under 35 U.S.C. § 119 to United States of American Application No. 62/856,274 filed on Jun. 3, 2019 and Japanese Application No. 2020-079489 filed on Apr. 28, 2020, the entire contents of which are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62856274 | Jun 2019 | US |
