WO2022158000A1

WO2022158000A1 - Impeller, motor, and vacuum cleaner

Info

Publication number: WO2022158000A1
Application number: PCT/JP2021/021978
Authority: WO
Inventors: 心路竹本; 哲梶川
Original assignee: 日本電産株式会社
Priority date: 2021-01-25
Filing date: 2021-06-09
Publication date: 2022-07-28

Abstract

One aspect of an impeller of the present invention is an impeller that is rotated in the circumferential direction centered around the central axis extending in the axial direction and includes a plurality of first blades arranged circumferentially. Each of the plurality of the first blades includes: a centrifugal blade part that includes a centrifugal blade surface facing the circumferential direction; and an axial flow blade part that includes an axial flow blade surface facing the axial direction and is connected to the radially outer side of the centrifugal blade part. The centrifugal blade surface is a curved surface that is curved toward one side in the circumferential direction from the radially inner side to the radially outer side. The centrifugal blade surface has a radially inner end that is inclined toward the other side in the circumferential direction as it goes radially outward with respect to the radial direction.

Description

impeller, motor, and vacuum cleaner

The present invention relates to impellers, motors and vacuum cleaners.

An electric motor having a structure in which a rotor is provided with fins is known. For example, Patent Literature 1 describes a fin that sends air outward from the center side by centrifugal force.

Japanese Patent No. 5297398

For example, for the purpose of cooling the electric motor, it may be required to flow the air sent radially outward by the fins as described above along the axial direction of the electric motor. In such a case, the fins are required to efficiently flow air along the axial direction.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an impeller capable of improving the efficiency of blowing air in the axial direction, a motor provided with such an impeller, and a vacuum cleaner provided with such a motor.

One aspect of the impeller of the present invention is an impeller that rotates in the circumferential direction around a central axis that extends in the axial direction, and that includes a plurality of first blades arranged along the circumferential direction. Each of the plurality of first blades has a centrifugal blade portion having a centrifugal blade surface facing the circumferential direction and an axial blade portion having an axial blade surface facing the axial direction, and is connected to the radially outer side of the centrifugal blade portion. and have The centrifugal blade surface is a curved surface that curves to one side in the circumferential direction from the radially inner side to the radially outer side. The radially inner end portion of the centrifugal blade surface is inclined with respect to the radial direction so as to be located on the other side in the circumferential direction toward the radially outer side.

One aspect of the motor of the present invention includes the impeller described above and a motor main body that rotates the impeller.

One aspect of the vacuum cleaner of the present invention includes the motor described above.

According to one aspect of the present invention, the efficiency of blowing air in the axial direction by the impeller can be improved.

FIG. 1 is a cross-sectional view showing the motor of the first embodiment. FIG. 2 is a perspective view showing part of the impeller of the first embodiment. FIG. 3 is a top view of part of the impeller of the first embodiment. FIG. 4 is a cross-sectional view showing the axial flow blade portion of the first embodiment. FIG. 5 is a top view of part of the impeller of the second embodiment. FIG. 6 is a perspective view showing part of the impeller of the third embodiment. FIG. 7 is a perspective view showing the vacuum cleaner of one embodiment.

[Motor embodiment]
<First embodiment>
A motor 10 of the present embodiment shown in FIG. 1 is an inner rotor type motor. As shown in FIG. 1 , the motor 10 includes a motor main body 20, an impeller 30, a motor housing 40, an impeller housing 50, and a flow path member 60.

The motor main body 20 rotates the impeller 30 around the central axis J. The central axis J is a virtual line shown in FIG. In each figure, the direction in which the central axis J extends is indicated by the Z-axis. In the following description, the direction in which the central axis J extends, that is, the direction parallel to the Z axis, is simply referred to as the "axial direction," and the radial direction about the central axis J is simply referred to as the "radial direction." is simply referred to as the "circumferential direction".

The arrow θ appropriately shown in the figure indicates the circumferential direction. In the following description, of the circumferential direction, the side proceeding clockwise about the central axis J as viewed from above, that is, the side to which the arrow θ is directed (+θ side) is referred to as "one side in the circumferential direction". The side proceeding counterclockwise about the center axis J as viewed from above, that is, the side opposite to the side to which the arrow θ is directed (−θ side) is called the “other side in the circumferential direction”.

In the following description, the side of the axis where the arrow of the Z-axis points (+Z side) is referred to as the "upper side", and the side of the axis opposite to the side where the arrow of the Z-axis points (-Z side). Call it "bottom". In this embodiment, the upper side corresponds to "one side in the axial direction" and the lower side corresponds to "the other side in the axial direction". Further, the upper side and the lower side are simply names for explaining the relative positional relationship of each part, and the actual arrangement relationship etc. may be an arrangement relationship etc. other than the arrangement relationship etc. indicated by these names. .

The motor main body 20 has a rotor 21 and a stator 22 . The rotor 21 is rotatable around a central axis J extending in the axial direction. The rotor 21 has a shaft 21a and a rotor body 21b. The shaft 21a has a columnar shape extending in the axial direction around the central axis J. As shown in FIG. The rotor body 21b is fixed to the outer peripheral surface of the shaft 21a. Although not shown, the rotor body 21b has a rotor core fixed to the shaft 21a and magnets held by the rotor core.

The stator 22 is arranged to face the rotor 21 with a gap in the radial direction. The stator 22 is positioned radially outside the rotor 21 . The stator 22 has a stator core 22a, an insulator 22b, and a plurality of coils 22c. The stator core 22a has an annular shape surrounding the rotor body 21b. A plurality of coils 22c are attached to stator core 22a via insulators 22b.

The motor housing 40 accommodates the motor body 20 inside. The motor housing 40 has a motor housing body 41 and a bearing holder 42 . The motor housing main body 41 has a cylindrical shape with a bottom portion on the lower side and an opening on the upper side. A stator 22 is fixed to the inner peripheral surface of the motor housing main body 41 . A bearing 43 that rotatably supports the shaft 21 a is held at the bottom of the motor housing main body 41 . The bearing holder 42 is attached to the upper opening of the motor housing main body 41 . The bearing holder 42 has a through hole 42a that passes through the bearing holder 42 in the axial direction. The shaft 21a is axially passed through the through hole 42a. An upper end of the shaft 21a protrudes above the motor housing 40 through the through hole 42a. A bearing 44 that rotatably supports the shaft 21a is held in the through hole 42a. In this embodiment, the

bearings

43 and 44 are ball bearings.

The impeller housing 50 is an annular member surrounding the central axis J. The impeller housing 50 is positioned above the motor housing 40 . The impeller housing 50 accommodates the impeller 30 inside. The impeller housing 50 has an impeller housing body 51 and an intake guide 52 .

The impeller housing body 51 has an annular shape surrounding the impeller 30 . The impeller housing main body 51 has a lid wall portion 51a and a peripheral wall portion 51b. The lid wall portion 51 a is positioned above the radially outer portion of the impeller 30 . The lid wall portion 51a has an annular shape surrounding the central axis J. As shown in FIG. The peripheral wall portion 51b has a tubular shape that protrudes downward from the radial outer peripheral edge portion of the lid wall portion 51a. The peripheral wall portion 51b is positioned radially outward of the impeller 30 . The air intake guide 52 has a cylindrical shape that protrudes upward from the radially inner peripheral edge of the impeller housing main body 51 . The intake guide 52 opens upward. An upper opening of the intake guide 52 is an intake port 50a.

The flow path member 60 is a tubular member that surrounds the motor housing 40 . The flow channel member 60 has a flow channel member body 61 and a plurality of stationary blades 62 . The flow path member main body 61 is located radially outside the motor housing 40 . The flow path member main body 61 has a cylindrical shape surrounding the motor housing 40 . An upper end portion of the flow path member main body 61 is fixed to a lower end portion of the peripheral wall portion 51 b of the impeller housing main body 51 .

The plurality of stationary blades 62 are positioned between the inner peripheral surface of the flow path member main body 61 and the outer peripheral surface of the motor housing 40 . Although not shown, the plurality of stationary blades 62 are arranged at intervals along the circumferential direction. The plurality of stationary vanes 62 protrude radially inward from the inner peripheral surface of the flow path member main body 61 .

The motor housing 40, the impeller housing 50, and the flow path member 60 constitute an exhaust flow path 70 extending in the axial direction. The exhaust flow path 70 extends downward from the radially outer side of the impeller 30 . The exhaust flow path 70 includes a first flow path portion 71 provided radially between the peripheral wall portion 51b and the impeller 30, and a first flow path portion 71 provided radially between the motor housing 40 and the flow path member main body 61. 2 channel portion 72 . The second channel portion 72 is connected to the lower side of the first channel portion 71 . A lower end portion of the second flow path portion 72 is an exhaust port 73 that opens downward. A plurality of stationary blades 62 are arranged in the second flow path portion 72 .

The impeller 30 is rotated in the circumferential direction about the axially extending central axis J by the motor main body 20 . In this embodiment, the impeller 30 is rotated in one circumferential direction (+θ direction). The impeller 30 is positioned above the bearing holder 42 . In this embodiment, the impeller 30 is fixed to a portion of the shaft 21a that protrudes above the through hole 42a. The impeller 30 includes a base portion 31 , a plurality of first blades 32 , a fixed portion 35 and a shroud 36 .

The base 31 is positioned above the bearing holder 42 . The base 31 widens in the radial direction. In this embodiment, the base 31 has a plate-like shape with a plate surface facing the axial direction. The base 31 has an annular shape surrounding the central axis J. As shown in FIG. A radially outer portion of the base portion 31 is positioned axially between the cover wall portion 51 a and the bearing holder 42 . The radial position of the radial outer edge of the base portion 31 is, for example, the same as the radial position of the outer peripheral surface of the motor housing 40 . A radially inner portion of the base portion 31 is exposed to the upper side of the motor 10 through the intake port 50a.

The fixed portion 35 protrudes downward from the radial inner edge of the base portion 31 . The fixed portion 35 has a cylindrical shape surrounding the shaft 21a. The fixed portion 35 is fixed to the shaft 21a by, for example, press fitting. A lower end portion of the fixed portion 35 is inserted into the through hole 42a. The lower end of the fixed portion 35 is in contact with the inner ring of the bearing 44 from above.

As shown in FIGS. 2 and 3, the plurality of first blades 32 are arranged along the circumferential direction. More specifically, the plurality of first blades 32 are arranged at regular intervals along the circumferential direction. In this embodiment, the plurality of first blades 32 protrude upward from the base portion 31 . The plurality of first blades 32 are provided on the radially outer portion of the base portion 31 . Each of the plurality of first blades 32 has a centrifugal blade portion 33 and an axial blade portion 34 .

The centrifugal blade portion 33 extends radially outward from the radially inner side. In this embodiment, the lower end of the centrifugal impeller 33 is connected to the base 31 . The radially outer end of the centrifugal vane portion 33 is positioned at the radially outer peripheral edge portion of the base portion 31 . As shown in FIG. 1, the radially inner end of the centrifugal vane portion 33 overlaps the intake port 50a when viewed in the axial direction. A radially inner end of the centrifugal blade portion 33 is exposed to the upper side of the motor 10 through the intake port 50a.

As shown in FIG. 3, the centrifugal blade portion 33 extends from the radially inner side toward the radially outer side while being inclined to the other circumferential side (-θ side) with respect to the radial direction. The radially outer end portion of the centrifugal blade portion 33 is located on the other circumferential side of the radially inner end portion of the centrifugal blade portion 33 . The centrifugal blade portion 33 has a curved shape protruding toward the other side in the circumferential direction when viewed in the axial direction. The centrifugal blade portion 33 is curved from the radially inner side toward the radially outer side in the circumferential direction (+θ side).

The centrifugal blade portion 33 has a centrifugal blade surface 33a facing the circumferential direction. In the present embodiment, the centrifugal impeller surface 33a is a surface of the centrifugal impeller portion 33 on one circumferential side (+θ side). That is, the centrifugal blade surface 33a is a surface facing one side in the circumferential direction. In this embodiment, the centrifugal blade surface 33a is a surface along the axial direction. The centrifugal blade surface 33a is, for example, parallel to the axial direction. The centrifugal blade surface 33a extends from the radially inner side to the radially outer side while being inclined to the other circumferential side (−θ side) with respect to the radial direction. The radially outer end of the centrifugal blade surface 33a is located on the other circumferential side of the radially inner end of the centrifugal blade surface 33a. The centrifugal blade surface 33a has a curved shape protruding toward the other side in the circumferential direction when viewed in the axial direction. The centrifugal blade surface 33a is a curved surface that curves from the radially inner side toward the radially outer side in the circumferential direction (+θ side).

The radially inner end of the centrifugal blade surface 33a is inclined toward the radially outer side in the circumferential direction (-θ side). In the present embodiment, the radially outer end of the centrifugal blade surface 33a is inclined with respect to the radial direction so as to be located on the other side in the circumferential direction toward the radially outer side. The radially inner end 33b of the centrifugal blade surface 33a has an inclination angle φ1 with respect to the radial direction that is greater than the radially inclined angle φ2 at the radially outer end 33c of the centrifugal blade surface 33a. The angle of inclination of the centrifugal blade surface 33a with respect to the radial direction decreases radially outward.

The axial vane portion 34 is connected to the radially outer side of the centrifugal vane portion 33 . In this embodiment, the axial vane portion 34 protrudes radially outward from the base portion 31 . In the present embodiment, the entire axial flow vane portion 34 is positioned radially outward of the base portion 31 . The axial flow blade portion 34 protrudes from the centrifugal blade portion 33 to the other side (−θ side) in the circumferential direction. The radial dimension of the axial vane portion 34 is smaller than the radial dimension of the centrifugal vane portion 33 . In other words, the radial dimension of the centrifugal vanes 33 is larger than the radial dimension of the axial vanes 34 . As shown in FIG. 1 , the axial vane portion 34 protrudes into the upper end portion of the exhaust passage 70 .

As shown in FIGS. 2 and 4, the axial vane portion 34 has an axial vane surface 34a facing the axial direction. The axial flow blade surface 34a is circumferentially inclined with respect to the axial direction. The axial flow blade surface 34a faces downward and obliquely to one side in the circumferential direction (+θ side). The axial flow blade surface 34a is positioned downward toward the other side (−θ side) in the circumferential direction. In this embodiment, the inclination angle φ3 of the axial flow blade surface 34a with respect to the axial direction increases radially outward. The radial inner end of the axial flow impeller surface 34a is connected to the radial outer end of the centrifugal impeller surface 33a.

As shown in FIG. 1, the shroud 36 is positioned above the first blade 32. The shroud 36 has an annular portion 36a and a cylindrical portion 36b. The annular portion 36a has an annular shape surrounding the central axis J. As shown in FIG. The annular portion 36a has a plate shape with a plate surface facing the axial direction. The upper end portions of the radially outer portions of the plurality of first blades 32 are connected to the lower surface of the annular portion 36a. In other words, the plurality of first blades 32 connect the base portion 31 and the annular portion 36a. A space between the base portion 31 and the annular portion 36 a in the axial direction is divided into a plurality of portions along the circumferential direction by the plurality of first blades 32 . The annular portion 36a is positioned between the cover wall portion 51a and the bearing holder 42 in the axial direction. The cylindrical portion 36b protrudes upward from the radial inner edge of the annular portion 36a. The cylindrical portion 36b has a cylindrical shape surrounding the central axis J. As shown in FIG. The cylindrical portion 36b is open upward. An upper opening of the cylindrical portion 36b is connected to the intake port 50a. The cylindrical portion 36b is located radially inside the lid wall portion 51a.

As shown by the arrow in FIG. 1, when the motor main body 20 rotates the impeller 30 in one circumferential direction (+θ direction), air flows into the impeller housing 50 from the intake port 50a. The air that has flowed into the impeller housing 50 flows into the impeller 30 through the upper opening of the cylindrical portion 36b. The air that has flowed into the impeller 30 flows radially outward in the space between the base portion 31 and the annular portion 36 a in the axial direction, and flows into the exhaust passage 70 . The air that has flowed into the exhaust passage 70 flows downward and is discharged from the motor 10 through the exhaust port 73 . The air flowing through the exhaust passage 70 cools the motor body 20 .

According to this embodiment, each of the plurality of first blades 32 has a centrifugal blade portion 33 and an axial blade portion 34 connected to the radially outer side of the centrifugal blade portion 33 . Therefore, as indicated by the arrow in FIG. 2, the air sent radially outward by the centrifugal impeller 33 can be sent axially by the axial impeller 34 connected to the radially outer side of the centrifugal impeller 33. Accordingly, by rotating the impeller 30 by the motor body 20, air can be sent in the axial direction.

Further, according to the present embodiment, the centrifugal impeller surface 33a of the centrifugal impeller portion 33 is a curved surface that curves from the radially inner side to the radially outer side in the circumferential direction (+θ side). The radially inner end portion of the centrifugal blade surface 33a is inclined toward the radially outer side toward the other circumferential side (−θ side). Therefore, the inclination angle of the centrifugal vane surface 33a with respect to the radial direction becomes smaller toward the radially outer side. Here, the smaller the inclination angle of the centrifugal blade surface 33a with respect to the radial direction, the greater the resistance that the centrifugal blade surface 33a receives from the air. That is, the resistance that the centrifugal blade surface 33a receives from the air increases radially outward. As a result, the centrifugal vane surface 33a becomes more difficult to send air radially outward in a portion located radially outward. Therefore, the air that has flowed from the radially outer end of the centrifugal vane surface 33a to the axial vane surface 34a of the axial vane portion 34 is less likely to flow radially outward, and is more likely to flow axially due to the axial vane surface 34a. Become. Therefore, it is possible to suppress the direction of the air sent in the axial direction by the axial flow blade surface 34a from tilting radially outward. As a result, the air can be preferably sent in the axial direction by the first blades 32 . Therefore, the air sent radially outward from the impeller 30 can be suitably flowed in the axial direction without being redirected by another member such as the wall of the exhaust passage 70 . Therefore, the pressure loss caused in the air sent by the impeller 30 can be reduced compared to the case where the air sent radially outward from the impeller 30 can change its flow direction by another member. Therefore, the efficiency of blowing air in the axial direction by the impeller 30 can be improved.

In the example of the present embodiment, the air sucked into the impeller 30 through the intake port 50a can be efficiently flowed through the exhaust passage 70 and discharged downward through the exhaust port 73 . Further, the motor body 20 can also be cooled by the air flowing through the exhaust passage 70 . Therefore, the cooling efficiency of the motor main body 20 can also be improved. In addition, since it is easy to cool the entire axial direction of the motor main body portion 20 with a single impeller 30, the motor 10 is less likely to cool than, for example, a case where a plurality of impellers are provided to cool the entire axial direction of the motor main portion 20. increase in the number of parts can be suppressed. In addition, it is possible to suppress an increase in the size of the motor 10 as a whole.

Further, according to this embodiment, the axial flow blade surface 34a is inclined in the circumferential direction with respect to the axial direction. A circumferential inclination angle φ3 of the axial flow blade surface 34a with respect to the axial direction increases radially outward. Here, the larger the inclination angle φ3 of the axial flow blade surface 34a with respect to the axial direction, the smaller the resistance that the axial flow blade surface 34a receives from the air. That is, the resistance that the axial flow blade surface 34a receives from the air decreases toward the radially outer side. In this way, the centrifugal vane surface 33a increases radially outwardly the resistance received by the air from the centrifugal vane surface 33a, while decreasing the radially outwardly exerted resistance received by the axial vane surface 34a from the air. It is possible to easily flow the air from the axial flow blade surface 34a to the axial flow blade surface 34a, and the axial flow blade surface 34a makes it easier to flow the air in the axial direction. Therefore, the efficiency of blowing air in the axial direction by the impeller 30 can be further improved.

Further, according to this embodiment, the centrifugal blade surface 33a is a surface along the axial direction. Therefore, air can be easily sucked from above in the axial direction between the centrifugal blade portions 33 in the circumferential direction. As a result, the amount of air sucked into the impeller 30 by the centrifugal vanes 33 can be increased. Therefore, the amount of air that can be sent axially by the impeller 30 can be increased. Therefore, the efficiency of blowing air in the axial direction by the impeller 30 can be further improved.

In addition, according to the present embodiment, the radial dimension of the centrifugal vane portion 33 is larger than the radial dimension of the axial vane portion 34 . Therefore, the radial dimension of the centrifugal blade portion 33 can be made relatively large. As a result, the amount of air sucked into the impeller 30 by the centrifugal vanes 33 can be increased. Thus, a greater amount of air can be pumped axially by the impeller 30 . Therefore, the efficiency of blowing air in the axial direction by the impeller 30 can be further improved. In addition, the radial dimension of the axial flow blade portion 34 can be made relatively small. Therefore, it is possible to prevent the impeller 30 from increasing in size in the radial direction. As described above, in the present embodiment, the direction of flow of a relatively large amount of air sucked by the centrifugal vanes 33 is changed to the axial direction by the axial vanes 34, so that a relatively large amount of air can be preferably sucked in the axial direction. It is possible to make the impeller 30 compact in the radial direction while allowing the air to flow through.

Further, according to this embodiment, the plurality of first blades 32 protrude upward from the base portion 31 . The axial flow blade surface 34a faces downward. Therefore, the air sucked from above between the centrifugal blade portions 33 can be flowed downward by the axial flow blade surface 34a. As a result, for example, by arranging the impeller 30 on the upper side of the motor main body 20 as in the present embodiment, the air sucked from the upper side flows downward, and the entire axial direction of the motor main body 20 is preferably Allow to cool.

Further, according to the present embodiment, the axial vane portion 34 protrudes radially outward from the base portion 31 . Therefore, the base portion 31 does not block the air sent downward by the axial flow blade portion 34 . As a result, the impeller 30 can more preferably send the air in the axial direction. Therefore, the efficiency of blowing air in the axial direction by the impeller 30 can be further improved. In this embodiment, by arranging the axial vanes 34 protruding radially outward in the upper end portion of the exhaust passage 70 , the air sent downward by the axial vanes 34 is preferably distributed in the exhaust passage 70 . can flow downwards.

<Second embodiment>
As shown in FIG. 5, the base portion 231 of the impeller 230 of this embodiment has a concave portion 231a that is recessed radially inward from the radial outer edge. In the present embodiment, the interior of the recessed portion 231a has a substantially quadrangular shape that curves and extends along the circumferential direction when viewed in the axial direction. A plurality of recesses 231a are provided at intervals in the circumferential direction. A recess 231 a is provided for each first blade 232 .

Each of the plurality of first blades 232 has a centrifugal blade portion 233 and an axial blade portion 234. In the present embodiment, the radially outer end of the centrifugal blade portion 233 is positioned at the radially inner edge 231b of the recess 231a. In the present embodiment, the radially outer end of the axial flow vane portion 234 is located at the same radial position as the radially outer edge of the base portion 231 . Therefore, the axial vane portion 234 does not protrude radially outward from the base portion 231 . As a result, it is possible to prevent the axial flow blade portion 234 from colliding with other components and being damaged. The radially outer end of the axial flow blade portion 234 may be positioned radially inward of the radially outer edge of the base portion 231 .

The axial flow blade portion 234 overlaps the interior of the recessed portion 231a when viewed in the axial direction. Therefore, the air sent downward by the axial flow vane portion 234 can be suitably flowed downward from the base portion 231 via the recessed portion 231a. By providing the concave portion 231a in this way, the axial vane portion 234 does not protrude radially outward from the base portion 231, and the air sent downward by the axial vane portion 234 is prevented from being blocked by the base portion 231. can. Other configurations of the impeller 230 are similar to other configurations of the impeller 30 of the first embodiment.

<Third Embodiment>
As shown in FIG. 6, in the first blades 332 of the impeller 330 of the present embodiment, the axial blade portions 334 are arranged in the other circumferential direction with respect to the centrifugal blade portion 33 than the axial blade portions 34 of the first embodiment. side (−θ side). The circumferential dimension of the axial vane portion 334 is larger than the circumferential dimension of the axial vane portion 34 of the first embodiment. The axial vane surface 334a of the axial vane portion 334 has a circumferential inclination angle φ3 with respect to the axial direction that is larger than that of the axial vane surface 34a of the first embodiment at the radially outer end. Other configurations of the first blade 332 are the same as other configurations of the first blade 32 of the first embodiment.

In this embodiment, the impeller 330 includes second blades 335 positioned between the axial flow blade portions 334 of the first blades 332 adjacent in the circumferential direction. The second blade 335 is positioned at the center of the axial flow blade portions 334 adjacent to each other in the circumferential direction. The second blade 335 is provided on the radial outer edge of the base 31 . The second blade 335 has a blade surface 335a facing in the axial direction. The shape of the second blade 335 is the same as the shape of the axial blade portion 334 . The shape of the blade surface 335a is the same as the shape of the axial flow blade surface 334a.

In this embodiment, the axial flow blade portion 334 and the second blade 335 that are adjacent in the circumferential direction partially overlap each other when viewed in the axial direction. More specifically, the end portion of the axial flow blade portion 334 on the other side in the circumferential direction (−θ side) is positioned below the second blade 335 adjacent to the other side in the circumferential direction. The end portion of the second blade 335 on the other side in the circumferential direction is positioned below the axial flow blade portion 334 adjacent to the other side in the circumferential direction. Other configurations of the impeller 330 are the same as the other configurations of the impeller 30 of the first embodiment.

According to this embodiment, in addition to the axial flow blade portion 334, the second blade 335 having the blade surface 335a can send air downward in the axial direction. Therefore, a greater amount of air can be sent axially by the impeller 330 . As a result, the efficiency of blowing air in the axial direction by the impeller 330 can be further improved. In addition, in the radially inner portion where the length of the entire circumference of the base portion 31 is relatively small, no other blade portion is provided between the centrifugal blade portions 33 that are adjacent in the circumferential direction. narrowing can be suppressed. Therefore, it is possible to prevent air from passing easily between the centrifugal blade portions 33 . As a result, it is possible to prevent the amount of air sucked by the centrifugal impeller 33 from decreasing. On the other hand, in the radially outer portion where the length of the entire circumference of the base portion 31 is relatively large, even if the second blade 335 is arranged between the axial flow blade portions 334, the axial flow blade portion 334 and the second blade 335 It is easy to sufficiently secure the space in the circumferential direction. Therefore, it is possible to prevent the air from becoming difficult to flow between the axial flow blade portion 334 and the second blade 335 .

Further, according to the present embodiment, the axial flow blade portion 334 and the second blade 335 partially overlap each other when viewed in the axial direction. By arranging the axial flow blade portion 334 and the second blades 335 in this manner, the static pressure of the air sent in the axial direction by the axial flow blade portion 334 and the second blades 335 can be increased. Therefore, a greater amount of air can be sent axially by the impeller 330 . As a result, the efficiency of blowing air in the axial direction by the impeller 330 can be further improved.

[Embodiment of Vacuum Cleaner]
As shown in FIG. 7, the cleaner 1000 of this embodiment is a stick-type cleaner. A vacuum cleaner 1000 includes the motor 10 of the first embodiment described above. As described above, the motor 10 can flow the air sucked from the intake port 50 a in the axial direction and efficiently discharge it from the exhaust port 73 . Therefore, by using the motor 10 in the cleaner 1000, the suction force of the cleaner 1000 can be efficiently improved. Instead of the motor 10, a motor equipped with the impeller 230 of the second embodiment may be mounted on the cleaner 1000, or a motor equipped with the impeller 330 of the third embodiment may be mounted on the cleaner 1000. good too. A vacuum cleaner equipped with the motor of each embodiment may be a canister type vacuum cleaner.

The present invention is not limited to the above-described embodiments, and other configurations and other methods can be adopted within the scope of the technical idea of the present invention. The number of first blades is not particularly limited as long as it is two or more. The centrifugal blade surface is a curved surface that curves to one side in the circumferential direction from the radially inner side to the radially outer side, and the radially inner end portion extends in the radial direction toward the radially outer side. It may have any shape as long as it is slanted toward the other side. The centrifugal impeller may have any shape as long as it has a centrifugal impeller surface. The axial flow blade surface may have any shape as long as it faces the axial direction. The inclination angle of the axial flow blade surface in the circumferential direction with respect to the axial direction may be the same throughout the radial direction. The axial vane portion may have any shape as long as it has an axial vane surface. An end portion of the axial flow blade portion on the other side in the axial direction may be connected to the base portion. The axial vane surface may be arranged axially opposite the base.

The base does not have to be provided. The impeller and at least a portion of the rotor of the motor body may be part of the same single member. In this case, the first blade may be provided directly on the rotor. The first blade may be configured to allow air to flow axially through a radial gap between the rotor and the stator of the motor main body. In this case, the axial flow blade portion may be arranged, for example, at a position axially facing the radial gap between the rotor and the stator. The impellers may be provided on both axial sides of the motor body.

For example, in the first embodiment described above, the shaft 21a may be protruded below the motor housing 40, and another impeller may be attached to the protruding portion of the shaft 21a. In this case, the other impeller may be an axial-flow impeller that causes air to flow downward, and the blades of the other impeller may be arranged below the exhaust port 73 so as to face each other. This makes it easier for the air to flow downward in the exhaust passage 70 , and makes it easier for the air to be discharged from the exhaust port 73 .

The use of the impeller and motor to which the present invention is applied is not particularly limited. A motor including an impeller may be mounted on a device other than a vacuum cleaner, such as a dryer. The impeller may be used only for cooling the motor. The impeller may not be used for motor cooling. The type of motor provided with the impeller is not particularly limited. It should be noted that each configuration and each method described in this specification can be appropriately combined within a mutually consistent range.

DESCRIPTION OF SYMBOLS 10... Motor 20... Motor main-

body part

30, 230, 330... Impeller, 31, 231... Base part, 32, 232, 332... First blade, 33, 233... Centrifugal blade part, 33a... Centrifugal blade surface, 34, 234, 334...

Axial blade portion

34a, 334a... Axial blade surface 231a... Recess 335... Second blade 335a... Blade surface 1000... Vacuum cleaner J... Central axis φ3... Inclination angle

Claims

An impeller circumferentially rotated about an axially extending central axis, comprising:
A plurality of first blades arranged along the circumferential direction,
Each of the plurality of first blades,
a centrifugal blade portion having a centrifugal blade surface facing the circumferential direction;
an axial vane portion having an axial vane surface facing the axial direction and connected to the radially outer side of the centrifugal vane portion;
has
The centrifugal blade surface is a curved surface that curves from the radially inner side to the radially outer side in the circumferential direction,
The impeller, wherein the radially inner end portion of the centrifugal blade surface is inclined with respect to the radial direction so as to be located on the other side in the circumferential direction toward the radially outer side.
The axial flow blade surface is circumferentially inclined with respect to the axial direction,
2. The impeller according to claim 1, wherein the inclination angle of the axial flow blade surface in the circumferential direction with respect to the axial direction increases radially outward.
The impeller according to claim 1 or 2, wherein the centrifugal blade surface is a surface along the axial direction.
The impeller according to any one of claims 1 to 3, wherein the radial dimension of the centrifugal blade portion is larger than the radial dimension of the axial flow blade portion.
further comprising a base,
The plurality of first blades protrude from the base portion to one side in the axial direction,
The impeller according to any one of claims 1 to 4, wherein the axial flow blade surface faces the other side in the axial direction.
The impeller according to claim 5, wherein the axial flow blade portion protrudes radially outward from the base portion.
the radially outer end of the axial flow blade portion is located at the same position in the radial direction as the radially outer edge of the base or radially inwardly of the radially outer edge of the base;
The base has a recess that is recessed radially inward from the radial outer edge,
6. The impeller according to claim 5, wherein the axial vane portion overlaps the interior of the recess when viewed in the axial direction.
further comprising a second blade positioned between the axial flow blade portions of the first blades adjacent in the circumferential direction,
8. An impeller as claimed in any preceding claim, wherein the second blades have axially facing blade surfaces.
an impeller according to any one of claims 1 to 8;
a motor body that rotates the impeller;
a motor.
A vacuum cleaner comprising the motor according to claim 9.