JP7354569B2 - Air blower and vacuum cleaner - Google Patents

Description

The present invention relates to an air blower and a vacuum cleaner.

An example of a conventional blower device is disclosed in Patent Document 1. The electric blower described in Patent Document 1 includes a centrifugal fan, an electric motor, and a fluid regulator. The electric motor includes a rotor, a stator, and a frame. The flow regulator includes an outer shell that supports and forms an outline of the frame, a main body disposed inside the outer frame, and an air passage formed between the outer frame and the main body. . The air passage portion has an inner diameter larger than an outer diameter of at least a portion of the stator core, and an outer diameter smaller than or equal to the inner diameter of the frame. Furthermore, the frame includes a regulating section. The regulating portion positions the frame in the circumferential direction with respect to the stator by stopping the stator core from rotating.

It is stated that with the above configuration, an air path from the air path section to the exhaust can be secured while suppressing the increase in size, and the air blowing efficiency of the electric blower can be improved.

Japanese Patent Application Publication No. 2018-084151

However, in the electric blower of Patent Document 1, it is difficult to cool the stator while suppressing a decrease in air blowing efficiency.

In view of the above situation, an object of the present invention is to provide an air blower that can cool a stator while suppressing a decrease in air blowing efficiency.

A blower device according to an exemplary embodiment of the present invention includes a rotor having a shaft arranged along a central axis extending vertically, a stator radially opposed to the rotor, and a stator fixed to the shaft and arranged at the central axis. It includes an impeller rotatable around an axis and a housing disposed below the impeller. The housing includes an annular inner annular portion fixed to the stator, and an annular inner annular portion arranged radially outward than the inner annular portion and forming a first flow path between the inner annular portion and the inner annular portion. The device includes an outer annular portion and a first rib connecting the inner annular portion and the outer annular portion. The stator communicates with the upper space of the first rib between the impeller and the inner annular portion in the axial direction, and the circumferential length at the radially outer end of the first rib is equal to the first rib. It is different from the circumferential length at the radially inner end of the rib.

According to the air blower of the present invention, the stator can be cooled while suppressing a decrease in air blowing efficiency.

FIG. 1 is a perspective view of a vacuum cleaner according to an exemplary embodiment of the invention. FIG. 2 is a perspective view of a blower device according to an exemplary embodiment of the invention. FIG. 3 is a longitudinal cross-sectional view of a blower device according to an exemplary embodiment of the invention. FIG. 4 is a top perspective view of a diffuser according to an exemplary embodiment of the invention. FIG. 5 is a perspective view from below of a diffuser according to an exemplary embodiment of the invention. FIG. 6 is a perspective view showing a housing and its surroundings according to an exemplary embodiment of the present invention. FIG. 7 is a plan view showing a housing and its surroundings according to an exemplary embodiment of the present invention. FIG. 8 is a cross-sectional view showing a housing and its surroundings according to an exemplary embodiment of the present invention. FIG. 9 is a plan view showing a housing and its surroundings according to an exemplary modification of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In this specification, the direction in which the central axis J of the blower 100 extends is referred to as a "vertical direction" or "axial direction," the direction perpendicular to the central axis J of the blower 100 is referred to as a "radial direction," and the center of the blower 100 is referred to as a "radial direction." A direction along an arc centered on the axis J is referred to as a "circumferential direction." However, the above-mentioned "vertical direction" does not limit the direction of the blower device 100 when it is actually incorporated into equipment. Further, in the drawings, the description in the drawings may differ from the actual structure for convenience.

Further, in this specification, the shape and positional relationship of each part of the vacuum cleaner A will be described with the direction approaching the floor surface F as "downward" and the direction away from the floor surface F as "upward." Note that these directions are simply names used for explanation, and do not limit the actual positional relationships and directions. Moreover, "upstream" and "downstream" respectively indicate upstream and downstream in the flow direction of the gas sucked in from the intake section 103 when the blower device 100 is driven.

A vacuum cleaner A according to an exemplary embodiment of the present invention will be described. FIG. 1 is a perspective view of a vacuum cleaner A according to an exemplary embodiment of the invention. The vacuum cleaner A is a so-called stick-type vacuum cleaner, and includes a housing 102 in which an intake section 103 and an exhaust section 104 are formed on the bottom and top surfaces, respectively. A power cord (not shown) is led out from the back of the housing 102. The power cord is connected to a power outlet (not shown) provided on the side wall of the living room, and supplies power to the vacuum cleaner A. Note that the vacuum cleaner A may be a so-called robot type, canister type, or handheld type vacuum cleaner.

An air passage (not shown) is formed within the housing 102 to connect the intake section 103 and the exhaust section 104. A dust collector (not shown), a filter (not shown), and a blower device 100 are arranged in this order from the upstream side to the downstream side in the air passage. The blower device 100 includes an impeller 30, which will be described later. Dust and other foreign substances contained in the gas flowing through the gas passage are blocked by the filter and collected in the dust collecting section formed in the shape of a container. The dust collecting section and the filter are configured to be removably attached to the housing 102.

A grip section 105 and an operation section 106 are provided at the top of the housing 102 . The user can move the vacuum cleaner A by gripping the grip part 105. The operation unit 106 has a plurality of buttons 106a, and the operation settings of the vacuum cleaner A are performed by operating the buttons 106a. For example, by operating the button 106a, instructions are given to start driving, stop driving, change the rotation speed, etc. of the blower device 100. A downstream end (upper end in the figure) of a rod-shaped suction pipe 107 is connected to the suction section 103 . A suction nozzle 108 is detachably attached to the upstream end of the suction tube 107 . Dust on the floor F is sucked into the suction pipe 107 through the suction nozzle 108.

The vacuum cleaner A includes a blower device 100, which will be described later. Thereby, in the vacuum cleaner A, the stator 20 can be cooled while suppressing a decrease in the air blowing efficiency of the air blower 100. The air blowing efficiency of the air blower 100 can be improved while cooling the motor 1 efficiently.

FIG. 2 is a perspective view of the blower device 100. FIG. 3 is a longitudinal cross-sectional view of the blower device 100. Referring to FIGS. 2 and 3, the blower device 100 includes a motor 1 and an impeller 30 that is rotationally driven by the motor 1. More specifically, the blower 100 includes a rotor 10, a stator 20, an impeller 30, and a housing 50. In this embodiment, the air blower 100 further includes a diffuser 40.

The motor 1 includes a rotor 10 and a stator 20. The rotor 10 includes a shaft 11 and a magnet 12. More specifically, the rotor 10 has a shaft 11 arranged along a central axis J that extends vertically. Magnet 12 is fixed to shaft 11. The magnet 12 includes a plurality of annular magnet pieces 121 arranged in the axial direction. An upper spacer 13 is arranged above the magnet 12, and a lower spacer 14 is arranged below. The upper surface of the magnet 12 contacts the lower surface of the upper spacer 13, and the lower surface of the magnet 12 contacts the upper surface of the lower spacer 14. In this embodiment, the magnet 12 is fixed to the radially outer surface of the shaft 11 with an adhesive. However, the magnet 12 may be fixed to the shaft 11 by other means, or may be fixed indirectly to the shaft 11 via another member.

Referring to FIGS. 3, 7, and 8, stator 20 includes a stator core 21, an insulator 22, and a coil 23. Stator 20 faces rotor 10 in the radial direction. More specifically, the stator 20 faces the magnet 12 in the radial direction. The stator 20 includes a stator core 21 made of a magnetic material, an insulator 22 made of an insulating material, and a coil 23. Stator core 21 includes an annular core back 211 and a plurality of teeth 212. The plurality of teeth 212 extend radially inward from the core back 211 and are arranged in the circumferential direction. The insulator 22 covers at least a portion of the upper surface of the teeth 212. More specifically, the insulator 22 includes an upper insulator 221 that covers at least a portion of the upper surface of the teeth 212 and a lower insulator 222 that covers at least a portion of the lower surface of the teeth 212.

The coil 23 is formed by winding a conductive wire around the teeth 212 via the insulator 22. That is, the stator 20 includes an annular core back 211, a plurality of teeth 212 extending radially inward from the core back 211 and arranged in the circumferential direction, and a plurality of coils 23 formed on the teeth 212. . The ends of the conductive wires are electrically connected to terminals 25 . The terminal 25 is housed in the terminal holder 24. The terminal holder 24 is a part of the lower insulator 222, and is formed as an integral member made of the same material as the lower insulator 222. The terminal 25 is electrically connected to a substrate 80, which will be described later. Thereby, for example, power from an external power source is supplied to the conductor via the substrate 80. Note that the terminal holder 24 may be configured as a separate member from the lower insulator 222. Further, the conductive wire may be electrically connected to the substrate 80 by other means or other members.

Impeller 30 is fixed to shaft 11. The impeller 30 includes a main plate 31, a plurality of moving blades 32, and a shroud 33. The main plate 31 is a portion that extends in a direction substantially perpendicular to the central axis J. The plurality of rotor blades 32 extend upward from the upper surface of the main plate 31 and are arranged at approximately equal intervals in the circumferential direction. The shroud 33 is disposed above the main plate 31, and the upper ends of the plurality of rotor blades 32 are connected to the shroud 33.

The impeller 30 is fixed to the upper end of the shaft 11 by an annular hub 34. Thereby, the impeller 30 is fixed to the shaft 11 and is rotatable around the central axis J. Note that the impeller may be a so-called mixed flow impeller. That is, the main plate 31 may be a curved surface that extends downward as it goes radially outward. Furthermore, the impeller may not be provided with a shroud. Moreover, the impeller 30 and the shaft 11 may be fixed by other means.

The shroud 33 has an axially opening opening 37 in the center. Therefore, when the impeller 30 rotates due to the rotation of the motor 1, the gas above the shroud 33 is sucked downward through the opening 37, flows radially outward by the rotor blades 32, and flows radially outward than the impeller 30. Expelled outward.

Impeller 30 is surrounded by impeller cover 70. That is, the impeller cover 70 surrounds the impeller 30 radially outward and above. An intake port 71 is configured at the center of the impeller cover 70. The intake port 71 communicates with the opening 37 . That is, the gas disposed near the intake port 71 is sucked into the impeller cover 70 as the impeller 30 rotates, and into the impeller 30 through the opening 37.

The diffuser 40 is arranged below the impeller 30 and above the inner annular portion 51. The inner annular portion 51 will be described later. The diffuser 40 includes a base portion 41 and a plurality of first stationary blades 42. The base portion 41 expands in a direction intersecting the central axis J. That is, the base plate 41 may extend in a direction substantially perpendicular to the central axis J, or may have, for example, an inclined surface or a curved surface that expands upward as it moves away from the central axis J. The plurality of first stationary blades 42 are arranged in the circumferential direction on the lower surface of the base portion 41. In this embodiment, the diffuser 40 further includes a second stationary blade 43 and an outer cylinder part 44. The outer cylinder portion 44 is a cylindrical portion that extends in the axial direction beyond the radial outer edge 411 of the base portion 41 in the radial direction. The radial outer edge 411 of the base portion 41 and the outer cylinder portion 44 are connected by the second stationary blade 43 . Details of the diffuser 40 will be described later.

The housing 50 will be described with reference to FIGS. 3 and 6 to 8. FIG. 6 is a perspective view showing the housing 50 and its surroundings according to an exemplary embodiment of the invention. FIG. 7 is a plan view showing the housing 50 and its surroundings according to an exemplary embodiment of the invention. FIG. 8 is a cross-sectional view showing the housing 50 and its surroundings according to an exemplary embodiment of the invention. Note that details of the housing 50 will be described later.

The housing 50 is arranged below the impeller 30. More specifically, the housing 50 is arranged below the diffuser 40. The housing 50 includes an annular inner annular portion 51, an annular outer annular portion 52, and a first rib 53. The inner annular portion 51 and the outer annular portion 52 are concentric. Inner annular portion 51 is fixed to stator 20 . More specifically, the inner annular portion 51 is arranged above the stator core 21 and fixed to each other by a fixing member 56. Note that the inner annular portion 51 and the stator 20 may be fixed by other means or other members.

The outer annular portion 52 is arranged radially outward than the inner annular portion 51. The outer annular portion 52 is a cylindrical portion extending in the axial direction. The upper end portion of the outer annular portion 52 is fixed to the outer cylinder portion 44 and the lower end portion of the impeller cover 70. The inner annular portion 51 and the outer annular portion 52 are connected by a first rib 53. The outer annular portion 52 forms a first flow path C1 between the outer annular portion 52 and the inner annular portion 51 in the radial direction. The first flow path C1 is a cylindrical space that extends in the axial direction beyond the impeller 30 in the radial direction. In this embodiment, the radial inner surface of the outer cylinder section 44 and the radial inner surface of the outer annular section 52 are substantially flush with each other, and the radial outer edge 411 of the base section 41 and the radial outer edge of the inner annular section 51 are substantially flush with each other. It is one. That is, the gas guided downward by the second stator vane 43 flows downward in the first flow path C1. The first flow path C1 is configured such that a cylindrical space centered on the central axis J is partitioned in the circumferential direction by first ribs 53. The gas discharged from the impeller 30 flows downward between the second stationary blades 43 of the diffuser 40 in the circumferential direction, and flows downward through the first flow path C1. In FIG. 3, the first flow path C1 is indicated by a dashed arrow. Note that the diffuser 40, the housing 50, and the impeller cover 70 may be fixed to each other using different configurations.

The housing 50 includes a plurality of second ribs 54. Furthermore, the housing 50 further includes a bearing holding section 55. The second rib 54 extends from the inner annular portion 51 in a direction approaching the central axis J. The plurality of second ribs 54 are arranged in the circumferential direction. In this embodiment, three second ribs 54 extend radially inward and are arranged at equal intervals in the circumferential direction. The bearing holding portion 55 is connected to the radially inner end of the second rib 54 and has a cylindrical shape extending in the axial direction. The bearing holding part 55 is substantially coaxial with the inner annular part 51 and the outer annular part 52. A bearing 60 is fixed to the radially inner surface of the bearing holding portion 55 . The bearing 60 rotatably supports the shaft 11.

The second rib 54 extends upward as it approaches the central axis J. At least a portion of the bearing 60 is arranged above the lower end of the first stationary blade 42. That is, at least a portion of the bearing 60 overlaps the radially inner end of the first stationary blade 42 via the bearing holding portion 55 in the radial direction. As a result, compared to, for example, a case where the radially inner end of the first stator vane 42 extends close to the shaft 11 and the upper end of the bearing 60 is arranged below the lower end of the first stator vane 42, The length of the blower device 100 in the axial direction can be reduced. Furthermore, since the bearing 60 can be placed as close to the impeller 30 as possible, the load that the bearing 60 receives when the impeller 30 rotates is reduced compared to when the bearing 60 is placed lower than the above configuration. can do.

The inner annular portion 51, the outer annular portion 52, and the first rib 53 are integrally molded members made of the same material. That is, the inner annular portion 51, the outer annular portion 52, and the first rib 53 are integral members continuously molded from the same material. This improves the mass productivity of the housing 50 and improves its rigidity. Furthermore, since the inner annular part 51, the outer annular part 52, and the first rib 53 are made of a single member, the dimensional accuracy of the inner annular part 51, the outer annular part 52, and the first rib 53 is improved. The dimensional accuracy of the first flow path C1 is improved, and generation of turbulent flow within the first flow path C1 can be suppressed. Note that the inner annular portion 51, the outer annular portion 52, and the first rib 53 may be composed of two or more members.

A lower housing 58 is arranged below the stator 20. The lower housing 58 is fixed to the housing 50 by a fixing member 582. Note that the lower housing 58 may be fixed to at least a portion of the stator core 21 or the housing 50 by other fixing means. The lower housing 58 includes a first protrusion 581 that protrudes upward at the radially inner end. A bearing 60 is fixed to the radially inner surface of the first protrusion 581 . That is, the rotor 10 of this embodiment is rotatably supported around the central axis J by a bearing 60 disposed above the stator 20 and a bearing 60 disposed below the stator 20. A substrate 80 is arranged below the lower housing 58. The substrate 80 is a plate-shaped member that extends in a direction substantially perpendicular to the central axis J. The substrate 80 is fixed to the lower housing 58 by a fixing member 583.

Next, the diffuser 40 will be explained with reference to FIGS. 4 and 5. FIG. 4 is a top perspective view of a diffuser 40 according to an exemplary embodiment of the invention. FIG. 5 is a perspective view from below of a diffuser 40 according to an exemplary embodiment of the invention.

The diffuser 40 includes a base portion 41 and a plurality of first stationary blades 42. The base portion 41 expands in a direction intersecting the central axis J. In this embodiment, the base portion 41 expands in a direction substantially perpendicular to the central axis J. The plurality of first stationary blades 42 are arranged in the circumferential direction on the lower surface of the base portion 41. The plurality of first stationary blades 42 extend forward in the rotation direction R as they approach the central axis J. Thereby, a second flow path C2 that communicates between the radially outer side and the radially inner side of the inner annular portion 51 is configured. Therefore, a part of the gas flowing radially outward from the radially outer end 421 of the first stationary blade 42 is smoothly guided in a direction approaching the central axis J by the second flow path C2, so that the gas is By hitting the coil 23, the coil 23 can be efficiently cooled. The plurality of first stationary blades 42 form a curved surface that is convex forward in the rotation direction R of the impeller 30. The plurality of first stationary blades 42 are arranged above the inner annular portion 51.

The diffuser 40 further includes a plurality of second stationary blades 43 and an outer cylinder part 44. The plurality of second stationary blades 43 are portions that extend radially outward from the radially outer edge 411 of the base portion 41 . The outer cylinder portion 44 is a cylindrical portion that is connected to the radially outer ends 433 of the plurality of second stationary blades 43 and extends in the axial direction. The outer cylindrical portion 44 is substantially coaxial with the outer annular portion 52.

The diffuser 40 has a plurality of second stator vanes 43 arranged in the circumferential direction radially outward from the radially outer edge 411 of the base portion 41 . The second stationary blade 43 extends downward in the forward rotation direction R. The second stationary blade 43 is arranged above the first flow path C1. Thereby, the gas flowing outside the base portion 41 in the radial direction can be smoothly guided downward. Therefore, the air blowing efficiency of the air blower 100 is improved. Furthermore, the efficiency of blowing the gas flowing through the first flow path C1 is also improved. The second stationary blade 43 extends downward as it goes forward in the rotation direction R of the impeller 30. A flow path partitioned in the circumferential direction by the plurality of second stator vanes 43 is configured in a space radially outward from the radially outer edge 411 of the base portion 41 .

Further, the stator 20 communicates with the upper space of the first rib 53 between the impeller 30 and the inner annular portion 51 in the axial direction. More specifically, the plurality of first stationary blades 41 constitute a second flow path C2 that communicates the radially outer side and the radially inner side of the inner annular portion 51. The second flow path C2 is indicated by a dashed arrow in FIG. 3 and by a solid arrow in FIG. 5. As a result, a part of the gas flowing radially outward from the radially outer end 421 of the first stationary blade 42 is smoothly guided in a direction approaching the central axis J by the second flow path C2. The coil 23 can be efficiently cooled by the gas hitting the coil 23. On the other hand, the other part of the gas flowing radially outwardly from the radially outer end 421 of the first stator blade 42 flows downwardly radially outwardly from the radially outer edge 411 of the base portion 41, It is discharged downward along the first flow path C1. That is, a part of the gas discharged radially outward from the impeller 30 flows radially outward and downward from the inner annular portion 51 along the first flow path C1, and the other part It flows in a direction approaching the central axis J along the second flow path C2. Thereby, the motor 1 can be cooled while improving the air blowing efficiency of the air blower 100.

It is preferable that at least a portion of the first stationary blade 42 opposes the inner annular portion 51 in the axial direction with a gap therebetween. As a result, compared to the case where the lower end of the first stationary blade 42 is in contact with the upper surface of the inner annular portion 51, the gas flows smoothly in the second flow path C2, so that the cooling characteristics of the motor 1 are improved. improves.

More specifically, the axial gap between the lower end of the first stator blade 42 and the upper surface of the inner annular portion 51 may be longer than half the axial length at the radially outer end 421 of the first stator blade 42. preferable. This makes it possible to increase the axial length of the first stator vane 42 and widen the axial gap between the lower end of the first stator vane 42 and the upper surface of the inner annular portion 51. Air blowing efficiency within C2 is improved. Therefore, the motor 1 can be efficiently cooled.

It is preferable that the lower end 432 at the radially inner end 431 of the second stator vane 43 is disposed higher than the lower end 422 at the radially outer end 421 of the first stator vane 42 . Thereby, the gas guided by the second stationary vanes 43 can be guided more smoothly to the second flow path C2, so that the motor 1 can be efficiently cooled.

To be more specific, the axial length of the second stator blade 43 at the radially inner end 431 of the second stator blade 43 is approximately half of the axial length at the radially outer end 421 of the first stator blade 42. It is preferable that there be. Thereby, the gas guided by the second stationary vane 43 can be guided more smoothly to the second flow path C2.

It is preferable that the lower end 434 at the radially outer end 433 of the second stator vane 43 is located lower than the lower end 422 at the radially outer end 421 of the first stator vane 42 . Thereby, the axial length of the second stator blade 43 near the radially outer end 433 of the second stator blade 43 can be increased. Therefore, among the gases flowing radially outward of the base portion 41, the gases flowing near the radially outer ends 433 of the second stator vanes 43 can be smoothly guided downward. Therefore, the air blowing efficiency of the air blower 100 is improved. Furthermore, the efficiency of blowing the gas flowing through the first flow path C1 is also improved.

It is preferable that the first stationary blades 42 are arranged at equal intervals in the circumferential direction. Thereby, the second flow paths C2 can be arranged at equal intervals in the circumferential direction. Therefore, the airflow flowing through the second flow path C2 can be made uniform in the circumferential direction, and the motor 1 can be cooled as uniformly as possible in the circumferential direction.

The second stationary blades 43 are preferably arranged at equal intervals in the circumferential direction. As a result, the airflow guided downward by the second stator blades 43 can be made uniform in the circumferential direction, so that generation of turbulence in the flow path formed between the second stator blades 43 in the circumferential direction can be suppressed. , the air blowing efficiency of the air blower 100 is improved.

It is preferable that the number of first stationary blades 42 and the number of second stationary blades 43 be equal. Further, it is preferable that the circumferential position of the radially outer end 421 of each first stator blade 42 is substantially the same as the circumferential position of the lower end of each second stator blade 43. As a result, the gas guided downward by each of the second stator vanes 43 is smoothly guided to the second flow path C2 by the first stator vanes 42, so that the motor 1 can be efficiently operated while improving the air blowing efficiency. Can be cooled.

Next, the configuration of the housing 50 and its surroundings will be described with reference to FIGS. 6 to 8. It is preferable that the upper surface 541 of the second rib 54 extends downward as it goes forward in the rotation direction R of the impeller 30. Thereby, the gas flowing forward and downward in the rotational direction R of the impeller 30 along the second flow path C2 can be smoothly guided below the second rib 54. Therefore, the motor 1 can be cooled more efficiently. Note that the entire upper surface 541 of the second rib 54 may extend downward as it goes forward in the rotation direction R of the impeller 30, or as in the present embodiment, a portion of the upper surface 541 extends in the rotation direction R of the impeller 30. It may extend downward as it goes forward in direction R.

It is preferable that the upper surface 531 of the first rib 53 extends downward as it goes forward in the rotation direction R of the impeller 30. Thereby, the gas flowing forward and downward in the rotational direction R of the impeller 30 in the first flow path C1 can be smoothly guided forward and downward in the rotational direction R. Therefore, the air blowing efficiency of the air blower 100 is improved. Note that the entire upper surface 531 of the first rib 53 may extend downward as it goes forward in the rotation direction R of the impeller 30, or as in the present embodiment, a portion of the upper surface 531 extends in the rotation direction R of the impeller 30. It may extend downward as it goes forward in direction R.

The second rib 54 is preferably arranged between the plurality of coils 23 in the circumferential direction. As a result, compared to the case where the second rib 54 and the coil 23 overlap in the axial direction, the gas flowing in the second flow path C2 flows downward between the second ribs 54 adjacent in the circumferential direction. Since it hits the coil 23, the motor 1 can be efficiently cooled.

The circumferential length L1 at the radially outer end of the first rib 53 is different from the circumferential length L2 at the radially inner end of the first rib 53. Thereby, the stator 20 can be cooled while suppressing a decrease in the air blowing efficiency of the air blower 100. That is, by improving the degree of freedom in designing the shape of the first rib 53, the cross-sectional area of the first rib 53 in the first flow path C1 can be adjusted, thereby suppressing an increase in air blowing resistance in the first flow path C1. can. Further, since the shape and area of the upper surface 531 of the first rib 53 can be adjusted, the flow velocity or air volume of the airflow guided to the stator 20 by the upper surface 531 of the first rib 53 can be increased. can be cooled efficiently.

The first rib 53 is arranged radially outward of the teeth 212. In other words, at least a portion of the first rib 53 overlaps the teeth 212 in the circumferential direction. This improves the cooling efficiency of the stator 20. In other words, since the first rib 53 is arranged radially outward of the location where the coil 23 that easily generates heat is arranged in the stator 20, the gas guided radially inward by the first rib 53 is likely to hit the coil 23. Therefore, the stator 20 can be efficiently cooled.

The circumferential length L2 of the first rib 53 at the radially inner end is longer than the circumferential length L3 of the teeth 212. Accordingly, by increasing the circumferential length L2 of the radially inner end of the first rib 53, the area of the upper surface 531 of the first rib 53 increases, so that it is possible to increase the airflow flowing toward the stator 20. Therefore, the stator 20 can be efficiently cooled. Note that when the circumferential length of the teeth 212 changes along the radial direction, the circumferential length at the radially outer end of the teeth 212 may be set as the circumferential length L3 of the teeth 212.

In this embodiment, the circumferential length L1 at the radially outer end of the first rib 53 is shorter than the circumferential length L2 at the radially inner end of the first rib 53. Thereby, the air blowing efficiency can be improved by widening the flow passage cross-sectional area in the radially outer region where the flow velocity is relatively high in the first flow passage C1. On the other hand, since the area of the upper surface 531 of the first rib 53 can be increased in the radially inner region where the flow velocity is relatively slow in the first flow path C1, the airflow can be guided toward the stator 20 side. Therefore, the stator 20 can be cooled while suppressing a decrease in the air blowing efficiency of the air blower 100.

A rear side surface 532 of the first rib 53 in the rotation direction R of the impeller 30 is disposed toward the front side in the rotation direction R as it goes radially outward. That is, the radially outer end of the rotation direction R rear side surface 532 is arranged on the front side in the rotation direction R than the radial inner end of the rotation direction R rear side surface 532. As a result, the airflow exhausted by the impeller 30 heads forward in the rotational direction R and outward in the radial direction, so that the shape of the rotational direction R rear side surface 532 becomes a shape that follows the airflow. The flow path resistance can be reduced compared to the case where the flow path extends to . Therefore, the air blowing efficiency of the air blower 100 can be improved.

A front side surface 533 of the first rib 53 in the rotational direction of the impeller 30 extends substantially in the radial direction. That is, the circumferential position of the radially outer end of the rotational direction front side surface 533 and the circumferential direction position of the radial inner end of the rotational direction front side surface 533 are substantially the same. As a result, for example, the radial outer end of the rotational direction front side surface 533 is disposed further forward in the rotational direction R than the radial inner end of the rotational direction front side surface 533, the periphery of the first rib 53 is Since the length in the direction can be shortened, the cross-sectional area of the first flow path C1 can be increased, so that the air blowing efficiency is improved.

The upper surface 531 of the first rib 53 and the upper surface of the inner annular portion 51 are smoothly connected. Thereby, the airflow hitting the upper surface 531 of the first rib 53 is smoothly guided in a direction approaching the central axis J, and the stator 20 can be efficiently cooled. Note that it is preferable that the upper surface 531 of the first rib 53 and the upper surface of the inner annular portion 51 are substantially flush with each other. Thereby, the airflow hitting the upper surface 531 of the first rib 53 is guided in a direction closer to the central axis J more smoothly.

The circumferential length of the first rib 53 is longer than the circumferential length of the second rib 54. Thereby, it is possible to increase the area of the upper surface 531 of the first rib 53 and efficiently guide the airflow in a direction approaching the central axis J, while widening the circumferential gap between the circumferentially adjacent second ribs 54. Therefore, the airflow efficiently hits the stator 20, and the stator 20 can be efficiently cooled.

FIG. 9 is a plan view showing a housing 50A and its surroundings according to an exemplary modification of the present invention. In the description of the modified example, only the features that differ from the exemplary embodiment described above will be described. Portions that have the same configuration in the above-described exemplary embodiment and the modified example are denoted by the same reference numerals, and explanations thereof may be omitted.

The circumferential length L2A at the radially inner end of the first rib 53A is shorter than the circumferential length L1A at the radially outer end of the first rib 53A. Accordingly, by widening the upper surface 531A of the first rib 53A in the radially outer region where the flow velocity is relatively high, more gas can be guided toward the stator 20 side. Therefore, the stator 20 can be efficiently cooled.

The rotation direction R rear side surface 532A of the impeller 30 in the first rib 53A is a curved surface that extends forward in the rotation direction R as it goes radially inward and is convex in the rotation direction R rear. That is, the radially inner end of the rotation direction R rear side surface 532A is arranged further forward in the rotation direction R than the radial outer end of the rotation direction R rear side surface 532A. As a result, the flow passage cross-sectional area of the first rib 53A increases, for example, compared to the case where the rear side surface 532A in the rotation direction R extends substantially radially from the radially inner end to the radially outer end. More airflow can be guided to the stator 20 side. Therefore, the stator 20 can be efficiently cooled. Further, since the circumferential length of the first rib 53A is long in the radially outer region where the flow velocity is relatively high in the first flow path C1, the strength around the radially outer end of the first rib 53A can be improved. .

The radial outer end of the rotation direction R rear side surface 532A is disposed further rearward in the rotation direction R than the rotation direction R rear side surface of the teeth 212. As a result, the airflow directed forward and downward in the rotational direction R hits the upper surface 531A of the first rib 53A in the rotational direction R rearward than the rearward side surface of the teeth 212 in the rotational direction, and is smoothly guided toward the central axis J. Since it hits the coil 23, the coil 23 can be efficiently cooled.

The various technical features disclosed in this specification can be modified and combined without departing from the spirit of the technical creation.

INDUSTRIAL APPLICATION This invention can be utilized for the air blower for a vacuum cleaner, for example.

A Vacuum cleaner F Floor surface J Central axis R Rotation direction C1 First flow path C2 Second flow path L1, L1A Circumferential length L2, L2A Circumferential length L3 Circumferential length 100 Air blower 102 Housing 103 Intake part 104 Exhaust part 105 Grip part 106 Operation part 106a Button 107 Suction pipe 108 Suction nozzle 1 Motor 10 Rotor 11 Shaft 12 Magnet 121 Magnet piece 13 Upper spacer 14 Lower spacer 20 Stator 21 Stator core 211 Core back 212 Teeth 22 Insulator 221 Upper insulator 222 Lower Insulator 23 Coil 24 Terminal holder 25 Terminal 30 Impeller 31 Main plate 32 Moving blade 33 Shroud 34 Hub 37 Opening 40 Diffuser 41 Base portion 411 Radial outer edge 42 First stationary blade 421 Radial outer end 422 Lower end 43 Second stationary blade 431 Radial direction Inner end 432 Lower end 433 Radial outer end 434 Lower end 44 Outer cylindrical part 50, 50A Housing 51 Inner annular part 52 Outer annular part 53, 53A First rib 531, 531A Upper surface 532, 532A Rear side 533 Front side 54 Second rib 541 Upper surface 55 Bearing holding part 56 Fixing member 58 Lower housing 581 Projection part 582 Fixing member 583 Fixing member 60 Bearing 70 Impeller cover 71 Intake port 80 Board

Claims (13)

a rotor having a shaft disposed along a central axis extending vertically;
a stator facing the rotor in a radial direction;
an impeller fixed to the shaft and rotatable around the central axis;
a housing disposed below the impeller;
Equipped with
The housing includes:
an annular inner annular portion fixed to the stator;
an annular outer annular portion that is disposed radially outward than the inner annular portion and defines a first flow path between the inner annular portion and the inner annular portion;
a first rib connecting the inner annular part and the outer annular part;
Equipped with
The stator communicates with the upper space of the first rib between the impeller and the inner annular portion in the axial direction,
The circumferential length at the radially outer end of the first rib is different from the circumferential length at the radially inner end of the first rib,
The first rib has no through hole when viewed from the impeller side in the central axis direction;
Air blower. The inner annular portion is disposed above the stator core of the stator, and the inner annular portion is arranged above the stator core of the stator, and
The blower device according to claim 1, wherein the upper part of the stator is radially opposed to the upper part of the stator. The stator is
a stator core having an annular core back and a plurality of teeth extending radially inward from the core back and arranged in a circumferential direction;
an insulator that covers at least a portion of the upper surface of the teeth;
a coil formed by winding a conductive wire around the teeth via the insulator;
Equipped with
The blower device according to claim 1 or 2 , wherein the first rib is arranged radially outward of the teeth. The blower device according to claim 3, wherein a circumferential length of the first rib at a radially inner end is longer than a circumferential length of the teeth. The housing further includes a plurality of second ribs extending from the inner annular portion in a direction approaching the central axis and arranged in a circumferential direction,
The blower device according to claim 3 or 4, wherein the second rib is arranged between the plurality of coils in the circumferential direction. The blower device according to any one of claims 1 to 5 , wherein the inner annular portion, the outer annular portion, and the first rib are integrally molded members made of the same material. The blower device according to any one of claims 1 to 6 , wherein a circumferential length of the first rib at its radially outer end is shorter than a circumferential length of the first rib at its radially inner end. The blower device according to claim 7 , wherein a rear side surface of the first rib in the rotational direction of the impeller is disposed toward the front side in the rotational direction of the impeller as it goes radially outward. The blower device according to any one of claims 1 to 6 , wherein a circumferential length of the first rib at its radially inner end is shorter than a circumferential length of the first rib at its radially outer end. The rear side surface of the first rib in the rotational direction of the impeller is a curved surface that extends forward in the rotational direction of the impeller as it goes radially inward and is convex rearward in the rotational direction of the impeller. Air blower. further comprising a diffuser disposed below the impeller and above the inner annular part,
The diffuser is
a base portion extending in a direction intersecting the central axis;
a plurality of first stationary blades that are arranged in a circumferential direction on the lower surface of the base portion and extend forward in the rotational direction of the impeller as they approach the central axis;
The air blower according to any one of claims 1 to 10 , comprising: The diffuser further includes a plurality of second stator vanes that are arranged in the circumferential direction radially outward from the radially outer edge of the base portion and extend downward as the impeller moves forward in the rotational direction of the impeller ,
The blower device according to claim 11 , wherein the second stator vane is arranged above the first flow path. A vacuum cleaner comprising the air blower according to any one of claims 1 to 12 .

Images