JP2018193940A - Blower and cleaner - Google Patents

Abstract

SOLUTION: A blower comprises: an impeller which rotates around a vertically-extending center axis; a motor for rotating the impeller; a motor housing for accommodating the motor; and a fan casing which is arranged outside the motor housing in a radial direction, and constitutes a flow passage in a clearance between the motor housing and itself. A plurality of first stationary blades arranged in a peripheral direction, and extending in an axial direction, and second stationary blades arranged between the adjacent first stationary blades in the peripheral direction, and extending in the axial direction are arranged outside the motor housing in the radial direction, and upper ends of the second stationary blades are arranged at a lower side lower than upper ends of the first stationary blades and at a side higher than the lower ends of the first stationary blades.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a blower.

  A conventional centrifugal compressor is disclosed in Patent Document 1. The centrifugal compressor of Patent Document 1 includes a rotor, a diffuser, and a shroud.

  The rotor is configured by attaching an impeller and a bearing cartridge to a shaft. The diffuser has a hub, a peripheral wall, a plurality of radial vanes, and a plurality of axial vanes. Radial vanes are two-dimensional wings spaced circumferentially on the upper surface of the hub. The peripheral wall surrounds the hub at a distance from the hub. An axial vane is a two-dimensional wing that extends between a peripheral wall and a hub. The rotor is rotatably attached to the diffuser by a bearing cartridge. The shroud is attached to the diffuser so as to cover the impeller and the diffuser.

JP 2010-196705 A

  However, in Patent Document 1, since the radial vane and the axial vane are provided in different regions where air flows by the rotation of the impeller, the number of vanes is reduced in each region, and the peripheral vanes are surrounded by each other. The direction gap cannot be reduced. Therefore, there is a possibility that the air blowing efficiency is lowered.

  In view of the above situation, an object of the present invention is to provide a blower that can improve the blowing efficiency.

  An exemplary air blower of the present invention is disposed on an outer side in the radial direction of the motor housing, an impeller that rotates about a central axis that extends vertically, a motor that rotates the impeller, a motor housing that houses the motor, and the like. A fan casing that forms a flow path in a gap with the motor housing, and a plurality of first stationary blades that are arranged in the circumferential direction and extend in the axial direction on the radially outer side of the motor housing, and the circumferential direction A second stationary blade disposed between the first stationary blades adjacent to each other and extending in the axial direction, and an upper end of the second stationary blade is lower than an upper end of the first stationary blade, and It arrange | positions above the lower end of a said 1st stator blade.

  According to the exemplary air blower of the present invention, the air blowing efficiency can be improved.

FIG. 1 is a perspective view of a vacuum cleaner according to an embodiment of the present invention. FIG. 2 is a perspective view of a blower device according to an embodiment of the present invention. FIG. 3 is a perspective view showing a state where the fan casing is removed from the blower according to the embodiment of the present invention. FIG. 4 is a longitudinal sectional view of a blower device according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state in which a part of the fan casing is cut in the blower according to the embodiment of the present invention. FIG. 6 is a graph showing an example of the relationship between the number of stationary blades and the air blowing efficiency.

  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 of the blower extends is the “axial direction”, the direction orthogonal to the central axis of the blower is “radial”, and the direction along the arc centered on the central axis of the blower is These are referred to as “circumferential directions”, respectively. Further, the central axis extends in the “vertical direction”, and in this specification, the shape and positional relationship of each part will be described with the intake side as “upper side” with respect to the impeller. However, the above-mentioned “vertical direction” does not limit the positional relationship and direction when it is actually incorporated into a device. Further, “upstream” and “downstream” respectively indicate upstream and downstream in the flow direction of the air sucked from the intake port when the impeller is rotated.

  Further, in the present specification, in the vacuum cleaner, the shape and the positional relationship of each part will be described, assuming that the direction approaching the floor surface is “downward” and the direction away from the floor surface is “upward”. These directions are merely names used for explanation, and do not limit the actual positional relationship and direction. In addition, “upstream” and “downstream” respectively indicate upstream and downstream in the flow direction of the air sucked from the intake port when the blower is driven.

<1. Overall configuration of vacuum cleaner>
Here, a vacuum cleaner according to an exemplary embodiment of the present invention will be described. FIG. 1 shows a perspective view of a vacuum cleaner according to an embodiment of the present invention. A vacuum cleaner 100 shown in FIG. 1 is a so-called stick-type vacuum cleaner, and includes a housing 102 that opens an intake port 103 and an exhaust port 104 on a lower surface and an upper surface, respectively. A power cord (not shown) is led out from the back surface of the housing 102. The power cord is connected to a power outlet (not shown) provided on the side wall surface of the room and supplies power to the cleaner 100. The vacuum cleaner 100 may be a so-called robot type, canister type or handy type vacuum cleaner.

  An air passage (not shown) that connects the intake port 103 and the exhaust port 104 is formed in the housing 102. In the air passage, a dust collecting part (not shown), a filter (not shown) and the blower 1 are arranged in this order from the upstream side to the downstream side. Dust such as dust contained in the air flowing through the air passage is shielded by a filter and collected in a dust collecting portion formed in a container shape. The dust collection unit and the filter are configured to be detachable from the housing 102. Thereby, the floor surface F can be cleaned.

  A grip part 105 and an operation part 106 are provided on the upper part of the housing 102. The user can move the cleaner 100 while holding the grip 105. The operation unit 106 includes a plurality of buttons 106a, and performs operation settings of the cleaner 100 by operating the buttons 106a. For example, the operation of the button 106a is instructed to start driving, stop driving, and change the rotation speed of the blower 1. A downstream end (upper end in the figure) of a rod-like suction pipe 107 is connected to the intake port 103. A suction nozzle 110 is detachably attached to the suction tube 107 at the upstream end of the suction tube 107.

<2. Overall configuration of blower>
Next, the whole structure of the air blower 1 is demonstrated. FIG. 2 is a perspective view of the blower 1 according to one embodiment of the present invention. FIG. 3 is a perspective view showing a state where the fan casing 2 is removed from the blower 1. FIG. 4 is a longitudinal sectional view of the blower 1.

  The blower 1 is roughly divided into a fan casing 2, an impeller 3, a motor housing 4, a motor 5, an upper bearing 6, a lower bearing 7, and a substrate 8. When the impeller 3 is rotationally driven around the central axis C by the motor 5 in the rotation direction R, air is sucked into the fan casing 2 from the upper side and exhausted downward from the fan casing 2.

<2.1 Fan casing>
The blower 1 has a cylindrical fan casing 2 that is circular in cross section in plan view. The fan casing 2 accommodates the impeller 3 and the motor housing 4. The fan casing 2 has an upper case portion 2A and a lower case portion 2B. The upper case portion 2 </ b> A covers the impeller 3. The lower case part 2 </ b> B covers the motor housing 4. The upper case portion 2A and the lower case portion 2B may be configured as the same member or may be configured as separate members.

  A bell mouth 21 that is bent inward from the upper end and extends downward is provided at the upper end of the upper case portion 2A. An intake port 211 that opens in the vertical direction is provided at the upper end of the bell mouth 21. The intake port 211 is located above the upper end of the impeller 3. An exhaust port 22 that opens in the vertical direction is provided at the lower end of the lower case portion 2B. In addition, in the vacuum cleaner 1, the air blower 1 is provided so that the inlet port 211 may face downward (FIG. 1).

<2.2 Impeller>
The impeller 3 is configured by a resin molded product. The impeller 3 includes a base portion 31 and a plurality of blades 32. The diameter of the base portion 31 increases as it goes downward.

  The base portion 31 has a boss portion 311 that protrudes downward. The boss 311 is connected to the upper part of the shaft 53 described later by press fitting. The impeller 3 is rotated in the rotation direction R about the central axis C by the motor 5.

  The plurality of blades 32 are arranged in the circumferential direction on the outer peripheral surface of the base portion 31. The blade 32 is configured as the same member as the base portion 31. The upper part of the blade 32 is disposed on the front side in the rotational direction R with respect to the lower part. As a result, when the impeller 3 rotates, the air sucked from the intake port 211 is guided to the front side and the lower side in the rotation direction R, and is guided to a later-described flow path FL positioned below the impeller 3.

<About the motor housing>
The motor housing 4 has an upper housing 41 and a lower housing 42. The upper housing 41 is disposed above the lower housing 42. The motor housing 4 houses the motor 5 therein.

  The upper housing 41 has a cup-shaped base 411. The base portion 411 includes a cylindrical portion 4111 that opens downward, and an upper lid portion 4112 that is positioned above the cylindrical portion 4111. In the center of the upper lid portion 4112, a hole portion 4112A penetrating in the vertical direction is provided. The upper bearing 6 is fixed to the lower part of the hole 4112A. The upper bearing 6 is constituted by a ball bearing, but may be constituted by a sleeve bearing or the like.

  An annular groove 4112B that is recessed downward is provided on the upper surface of the upper lid portion 4112. Here, an annular impeller convex portion 31 </ b> A is provided on the lower surface of the base portion 31 of the impeller 3. At least a part of the impeller convex portion 31A is accommodated in the groove portion 4112B. Thereby, it can suppress that the airflow produced by rotation of the impeller 3 flows into the inner side (space SP) of the impeller 3. That is, the labyrinth effect is exhibited and the blowing efficiency of the blower 1 can be improved.

  A plurality of columnar protrusions (not shown) are provided on the inner peripheral surface of the cylindrical portion 4111. The columnar protruding portion protrudes radially inward from the inner peripheral surface of the cylindrical portion 4111 and extends in a column shape in the vertical direction. The columnar protrusion is provided with a screw hole (not shown) extending upward from the lower end.

  A plurality of first stationary blades 412 arranged in the circumferential direction are provided on the outer peripheral surface of the cylindrical portion 4111. The first stationary blade 412 extends in the axial direction. A plurality of second stationary blades 413 arranged in the circumferential direction are further provided on the outer peripheral surface of the cylindrical portion 4111. The second stationary blade 413 is disposed between the first stationary blades 412 adjacent in the circumferential direction. The configuration of the stationary blade will be described in detail later.

  The lower housing 42 is a cup-shaped member whose upper side opens. A bearing holding portion 421 is provided at the center of the bottom of the lower housing 42. The lower bearing 7 is held by the bearing holding portion 421. The lower bearing 7 is constituted by a sleeve bearing, but may be constituted by a ball bearing or the like.

  At the bottom of the lower housing 42, a plurality of exhaust ports 42 </ b> A opening in the circumferential direction are arranged on the outer side in the radial direction of the bearing holding portion 421. The exhaust port 42A is an opening for exhausting air that has cooled the stator 51, as will be described later.

  A plurality of base portions (not shown) projecting radially inward are provided on the inner peripheral surface side of the lower housing 42. The base part is provided with a screw hole (not shown) penetrating in the vertical direction. The relationship between the base portion and the columnar protrusion will be described later.

<2.4 Motor>
Below the impeller 3, a motor 5 accommodated in a motor housing 4 is disposed. The motor 5 includes a stator 51, a rotor 52, and a shaft 53. The stator 51 includes a stator core 511, a plurality of coils, and an insulator.

  The stator core 511 is configured by stacking electromagnetic steel plates in the vertical direction. The stator core 511 has an annular core back 5111 and a plurality of teeth (not shown). The plurality of teeth extend radially inward from the inner peripheral surface of the core back 5111 and are formed radially. The teeth are substantially T-shaped in plan view. The coil is configured to be wound around each of the teeth via an insulating insulator.

  In the vicinity of the base of the teeth, the inner peripheral surface and the outer peripheral surface of the core back 5111 are configured as flat surfaces. Thereby, coil collapse can be suppressed. Further, the inner peripheral surface and the outer peripheral surface of the core back 5111 other than the vicinity of the roots of the teeth are curved surfaces.

  The inner side surface of the above-described columnar protrusion of the upper housing 41 is configured as a flat surface, and the flat surface portion on the outer peripheral surface of the core back 5111 contacts the inner side surface, and the upper housing 41 is placed on the lower housing 42. The columnar protrusion of the upper housing 41 is placed on the base portion of the lower housing 42. The screw holes of the columnar protrusions and the screw holes of the base part are located in a row in the vertical direction, and bolts are screwed into both screw holes from below. Thereby, the upper housing 41 is fixed to the lower housing 42 with the bolts.

  In a state where the upper housing 41 is fixed to the lower housing 42, vent holes 411 </ b> A penetrating in the radial direction are provided at positions on both sides of the cylindrical protrusion 4111 in the circumferential direction and below the first stationary blade 412. Configured (FIG. 3). The operation of the vent hole 411A will be described later.

  Further, the curved surface portion on the outer peripheral surface of the core back 5111 is in contact with the curved inner peripheral surface of the cylindrical portion 4111. That is, the stator core 511 is in direct contact with the upper housing 41.

  The rotor 52 is disposed on the radially inner side of the stator 51. That is, the motor 5 is a so-called inner rotor type. The rotor 52 has a plurality of magnets.

  A shaft 53 extending in the vertical direction is fixed to the rotor 52. The shaft 53 is rotatably held by the upper bearing 6 and the lower bearing 7. The upper end portion of the shaft 53 is fixed to the boss portion 311 of the impeller 3.

<2.5 About the substrate>
The disc-shaped substrate 8 is disposed below the lower housing 42. The substrate 8 is configured by a rigid substrate or a flexible substrate. A lead wire (not shown) drawn from the coil of the motor 5 is electrically connected to a drive circuit (not shown) mounted on the substrate 8. Thereby, electric power can be supplied to the coil.

<About the configuration of 2.6 vanes>
As shown in FIG. 4, the space sandwiched between the outer peripheral surface of the upper housing 41 and the inner peripheral surface of the fan casing 2, and the space sandwiched between the outer peripheral surface of the lower housing 42 and the inner peripheral surface of the fan casing 2, A flow path FL is formed. A first stator blade 412 and a second stator blade 413 are disposed in the flow path FL.

  Here, in order to explain the configuration of the stationary blade, FIG. 5 shows a cross-sectional view of a state in which a part of the fan casing 2 is cut in the blower 1 to visualize the stationary blade. The first stationary blade 412 extending in the axial direction is disposed in the circumferential direction. The second stationary blade 413 extending in the axial direction is disposed between the first stationary blades 412 adjacent in the circumferential direction. The upper end of the second stationary blade 413 is disposed below the upper end of the first stationary blade 412 and above the lower end of the first stationary blade 412.

  Thereby, the air sucked from the intake port 211 by the rotation of the impeller 3 flows into the flow path FL from the upper end of the flow path FL and is sent to the first stationary blade 412. The air flowing between the first stator blades 412 adjacent in the circumferential direction is guided between the first stator blades 412, and then a part of the air flows between the pressure surface PS 1 of the first stator blade 412 and the second stator blade 413. Guided between the pressure surfaces MS2, and the other part is guided between the suction surface MS1 of the first stationary blade 412 and the pressure surface PS2 of the second stationary blade 413. The pressure surface is a surface on the rear side in the rotation direction R of the impeller 3 in the stationary blade, and the negative pressure surface is a surface on the front side in the rotation direction R of the impeller 3 in the stationary blade.

  The air guided between the stationary blades is exhausted from the lower exhaust port 22 to the outside. Here, the arrows shown in FIG. 4 indicate the flow of air. Thus, since the airflow is rectified by the first stationary blade 412 and the second stationary blade 413 and the air is blown, the blowing efficiency can be improved.

  That is, the blower 1 of the present embodiment has an impeller 3 that rotates about a central axis C that extends vertically, a motor 5 that rotates the impeller 3, a motor housing 4 that houses the motor 5, and a diameter that is larger than the motor housing 4. And a fan casing 2 which is disposed on the outer side in the direction and forms a flow path FL in a gap with the motor housing 4. And it arrange | positions in the radial direction outer side of the motor housing 4 between the some 1st stationary blade 412 arrange | positioned in the circumferential direction and extended in the axial direction, and the 1st stationary blade 412 adjacent in the circumferential direction, and extends in the axial direction. And the upper end of the second stationary blade 413 is disposed below the upper end of the first stationary blade 412 and above the lower end of the first stationary blade 412.

  As a result, a large number of stationary blades can be arranged in a specific region in the flow path FL, and the circumferential gap between the stationary blades can be reduced. Therefore, it is possible to improve the air blowing efficiency by the air flow generated by the rotation of the impeller 3. FIG. 6 shows an example of the relationship between the number of stationary blades and the air blowing efficiency. In the present embodiment, as an example, the number of first stationary blades 412 is 13, the number of second stationary blades 413 is 13, and the total number of stationary blades is 26. As shown in FIG. 6, it can be seen that the blowing efficiency increases as the number of stationary blades increases.

  As shown in FIG. 5, the lower end of the second stationary blade 413 is disposed below the lower end of the first stationary blade 412. As a result, air can be guided by the second stationary blade 413 even below the lower end of the first stationary blade 412, so that the blowing efficiency is improved as compared with the case where only the first stationary blade 412 is arranged. be able to.

  Further, at least a part of the first stationary blade 412 overlaps with the second stationary blade 413 in the axial direction view. Thereby, since more stationary blades can be arrange | positioned by arrange | positioning the 1st stationary blade 412 and the 2nd stationary blade 413 in the circumferential direction specific area | region in the flow path FL, ventilation efficiency can be improved.

  In addition, as described above, the stator core 511 directly contacts the upper housing 41. Here, if the upper housing 41 is made of metal, for example, the first stationary blade 412 and the second stationary blade 413 are made of metal. That is, at least a part of the motor 5 is in direct contact with the motor housing 4, and the first stationary blade 412 and the second stationary blade 413 are metal members.

  Thereby, the rigidity of a stationary blade can be improved by using a metal member. Further, heat is transmitted from the motor 5 to the stationary blade by heat conduction, and is radiated from the stationary blade to the air by heat transfer. By increasing the thermal conductivity of the stationary blade by using the metal member, the cooling performance of the motor 5 can be improved. For example, the stator core 511 and the motor housing 4 may be brought into contact with each other via another member. That is, at least a part of the motor 5 may indirectly contact the motor housing 4. In this case, the another member is preferably made of a material having high thermal conductivity.

  As described above, as an example, the number of each of the first stationary blade 412 and the second stationary blade 413 is 13 respectively. That is, the number of first stationary blades 412 is equal to the number of second stationary blades 413. Thereby, generation | occurrence | production of a turbulent flow can be suppressed by distributing a stationary blade equally in the circumferential direction, and ventilation efficiency can be improved.

  Further, the circumferential thickness of the second stationary blade 413 is thinner than the circumferential thickness of the first stationary blade 412. Thereby, compared with the case where the thickness of the 2nd stator blade 413 is thick, in the area | region where the 2nd stator blade 413 in the flow path FL is arrange | positioned, with the adjacent 1st stator blade 412 and the 2nd stator blade 413, it is. The circumferential width of the partitioned flow path FL can be increased. Accordingly, since the cross-sectional area of the flow path in the region where both the first stationary blade 412 and the second stationary blade 413 are arranged in the flow path FL, the blowing efficiency can be improved.

  In addition, a first lower curved surface CS1 that curves forward in the rotational direction R of the impeller 3 as it goes downward is formed at the lower end of the pressure surface PS1 of the first stationary blade 412. A second lower curved surface CS2 that curves forward in the rotational direction R of the impeller 3 as it goes downward is formed at the lower end of the pressure surface PS2 of the second stationary blade 413. The radius of curvature of the second lower curved surface CS2 is longer than the radius of curvature of the first lower curved surface CS1.

  Thereby, the lower end portion of the first stationary blade 412 having a large thickness in the circumferential direction is further curved, so that the air that has flowed downward along the first lower curved surface CS1 is peeled off immediately below the first stationary blade 412. Therefore, the occurrence of turbulent flow directly below the first stationary blade 412 can be suppressed.

  The radius of curvature of the second lower curved surface CS2 is preferably 1.8 to 2.5 times the radius of curvature of the first lower curved surface CS1. Thereby, when the air flowing through the pressure surface PS1 of the first stationary blade 412 is guided from the lower end of the first stationary blade 412 to the front side in the rotation direction R along the first lower curved surface CS1, the second stationary blade. It can suppress hitting to pressure surface PS2 of 413. Therefore, it is possible to suppress the occurrence of turbulent flow on the lower side of the first stationary blade 412 and the second stationary blade 413 and make the air flow as uniform as possible.

  The first stationary blade 412 has a first stationary blade upper portion 4121 inclined in the circumferential direction toward the rear side in the rotation direction R of the impeller 3 from the lower side toward the upper side, and is axially lower than the first stationary blade upper portion 4121. 1st stationary blade lower part 4122 located in the side. The second stationary blade 413 is inclined in the circumferential direction toward the rear side in the rotation direction R of the impeller 3 from the lower side toward the upper side, and is axially lower than the second stationary blade upper portion 4131 and the second stationary blade upper portion 4131. 2nd stationary blade lower part 4132 located in this.

  Thereby, since the air exhausted to the front side in the rotation direction R of the impeller 3 can be smoothly guided to the lower side in the axial direction along the first stationary blade upper portion 4121 and the second stationary blade upper portion 4131, the air blowing efficiency is improved. be able to.

  The first stationary blade upper portion 4121 includes a first pressure curved surface 4121A that is curved on the pressure surface PS1 side, and a first negative pressure curved surface 4121B that is curved on the negative pressure surface MS1 side. The second stationary blade upper portion 4131 includes a second pressure curved surface 4131A that is curved on the pressure surface PS2 side, and a second negative pressure curved surface 4131B that is curved on the negative pressure surface MS2 side.

  That is, the first stationary blade upper portion 4121 has a first curved surface (4121A, 4121B) that is curved rearward in the rotational direction R of the impeller 3 relative to the first stationary blade lower portion 4122, and the second stationary blade upper portion 4131 is The second stationary blade lower portion 4132 has second curved surfaces (4131A, 4131B) that are curved toward the rear side in the rotation direction R of the impeller 3.

  Thereby, since air can be smoothly induced | guided | derived by a 1st curved surface and a 2nd curved surface, ventilation efficiency can be improved. In addition, in the upper part of a stationary blade, the curved surface should just be comprised by at least one of the pressure surface side and the suction surface side. For example, an inclined surface as a flat surface that does not curve may be configured on either the pressure surface side or the suction surface side.

  The circumferential length L1 between the rotation direction R rear end of the impeller 3 in the first stationary blade 412 and the rotation direction R front end of the impeller 3 in the pressure surface PS1 of the first stationary blade upper portion 4121 is the second stationary blade. It is longer than the circumferential length L2 between the rotation direction R rear end of the impeller 3 at 413 and the rotation direction R front end of the impeller 3 at the pressure surface PS2 of the second stationary blade upper portion 4131.

  As a result, the curved surface 4121A of the pressure surface PS1 of the first stationary blade upper portion 4121 is greatly curved, so that the air flow is guided downward by the first stationary blade 412 and the guided air is further lowered by the second stationary blade 416. Can be guided.

  Further, the radius of curvature of the pressure surface (4121A) in the first curved surface is smaller than the radius of curvature of the pressure surface (4131A) in the second curved surface. Thereby, the air which has the turning component which goes to the rotation direction R front side of the impeller 3 by the 1st stationary blade upper part 4121 can be guide | induced to an axial direction lower side, and ventilation efficiency can be improved. In particular, the radius of curvature of the pressure surface on the second curved surface is preferably 1.8 to 2.2 times the radius of curvature of the pressure surface on the first curved surface.

  The second stationary blade lower portion 4132 has an extending surface S21 extending in the axial direction on the pressure surface PS2 side at a position below the lower end of the first stationary blade 412. Thereby, the air guided by the first stationary blade 412 and away from the first stationary blade 412 is smoothly guided downward along the extending surface S21. Therefore, it can suppress that the air which left | separated from the 1st stationary blade 412 peels from the 2nd stationary blade 413, and can improve ventilation efficiency.

  The first stationary blade lower portion 4122 has a first surface S1 extending in the axial direction on the pressure surface PS1 side, and the second stationary blade lower portion 4131 is a second surface S2 extending in the axial direction on the pressure surface PS2 side. Have The axial length of the first surface S1 is shorter than the axial length of the second surface S2. The stretched surface S21 is included in the second surface S2. Thereby, since the axial direction length of 2nd surface S2 is long, it can suppress that the airflow bent in the axial direction by the 1st stator blade 412 can peel from the 2nd stator blade 413, and can improve ventilation efficiency. it can. In particular, the axial length of the second surface S2 is preferably 0.2 to 0.65 times the axial length of the second stationary blade lower portion 4132.

  The axial length of the second stationary blade upper portion 4131 is preferably 0.2 to 0.5 times the axial length of the second stationary blade 413. Thereby, the air flow efficiency can be improved by guiding the airflow downward in the axial direction by the second stationary blade upper portion 4131.

  Further, in a region where the first stationary blade lower portion 4122 and the second stationary blade lower portion 4132 overlap in the circumferential direction, the first stationary blade 412 adjacent in the circumferential direction is disposed on the rear side in the rotational direction R of the impeller 3. The circumferential width W1 between the first stator blade 412 and the second stator blade 413 is the circumference between the first stator blade 412 and the second stator blade 413 arranged on the front side in the rotation direction R of the impeller 3. It is preferably 1.1 to 1.3 times the direction width W2. Thereby, since an airflow can be guided more to the flow path between the stationary blades located in the rotation direction R rear side of the impeller 3, the air blowing efficiency can be improved.

  Further, in the region where the first stationary blade 412 and the second stationary blade 413 overlap in the circumferential direction, the circumferential center of the second stationary blade 413 is arranged at the circumferential center between the first stationary blades 412 adjacent in the circumferential direction. The Thereby, ventilation efficiency can be improved by making the flow path between each stationary blade as uniform as possible.

  The axial length between the upper end of the first stationary blade 412 and the upper end of the second stationary blade 413 is shorter than the length of the circumferential gap between the upper ends of the first stationary blades 412 adjacent in the circumferential direction. Thus, by widening the circumferential gap between the upper ends of the first stationary blades 412, the cross-sectional area of the flow path between the first stationary blades 412 is increased, and more air flows between the first stationary blades 412. You can guide to the road.

  The axial length of the region where the first stator blade 412 and the second stator blade 413 overlap in the circumferential direction is 0.5 to 0.8 times the axial length of the first stator blade. preferable. Thereby, ventilation efficiency can be improved.

  In addition, the axial length of the second stationary blade 413 is longer than the axial length of the first stationary blade 412. Thus, by increasing the length of the second stationary blade 413, air is smoothly guided along the second stationary blade 413 also on the lower side of the flow path, so that turbulent flow is difficult to occur, and the air blowing efficiency Can be improved.

<3. About motor cooling>
As described above, the upper housing 41 is provided with the vent hole 411A. The vent hole 411A penetrates in the radial direction and communicates the flow path FL and the inside of the upper housing 41. As shown in FIG. 5, the vent hole 411 </ b> A is disposed immediately below the predetermined first stationary blade 412.

  Part of the air flowing through the flow path FL and rectified by the first stationary blade 412 and the second stationary blade 413 flows into the motor housing 4 through the vent hole 411A (FIG. 4). The air that has flowed in flows upward and flows into the space above the stator 51. The inflowing air passes downward through a gap formed in the stator 51 such as between the teeth, and is exhausted from the exhaust port 42 </ b> A of the lower housing 42. Thereby, the heat of the stator 51 becomes difficult to accumulate in the motor housing 4, and the cooling efficiency of the stator 51 can be improved.

  That is, the motor housing 4 is formed with a vent hole 411A that penetrates in the radial direction and communicates the flow path FL and the inside of the motor housing 4. Thereby, the cooling efficiency of the motor 5 can be improved.

<4. Other>
As described above, the vacuum cleaner 100 according to this embodiment includes the above-described blower 1. Thereby, the cleaner which improved ventilation efficiency is realizable. Note that the blower is not limited to a vacuum cleaner, and may be mounted on various OA equipment, medical equipment, transport equipment, or household electrical appliances other than the vacuum cleaner.

  Note that the above-described embodiment can be variously modified within the scope of the gist of the present invention.

  The present invention can be used for, for example, a blower for a vacuum cleaner.

  DESCRIPTION OF SYMBOLS 100 ... Vacuum cleaner, 1 ... Air blower, 2 ... Fan casing, 2A ... Upper case part, 2B ... Lower case part, 21 ... Bell mouth, 211 ... Intake port , 22 ... exhaust port, 3 ... impeller, 31 ... base part, 32 ... blade, 4 ... motor housing, 41 ... upper housing, 411 ... base part, 4111 ... · Cylindrical portion, 4112 ··· Upper lid portion, 411A ··· Ventilation hole, 412 ··· First stator blade, 4121 ··· Upper portion of first stator blade, 4121A · · · First pressure curved surface, 4121B · .. First negative pressure curved surface, 4122... First stationary blade lower portion, 413... Second stationary blade, 4131... Second stationary blade upper portion, 4131A. ..Second negative pressure curved surface, 4132 ... lower part of second stationary blade, 42 ... lower side how 42A ... exhaust port, 5 ... motor, 51 ... stator, 511 ... stator core, 5111 ... core back, 52 ... rotor, 53 ... shaft, 6 ... Upper bearing, 7 ... lower bearing, 8 ... substrate, PS1, PS2 ... pressure surface, MS1, MS2 ... negative pressure surface, CS1 ... first lower curved surface, CS2 ... second Lower curved surface, S1 ... first surface, S2 ... second surface, S21 ... extended surface, FL ... flow path, C ... center axis, R ... rotation direction

Claims (24)

An impeller rotating around a central axis extending vertically;
A motor for rotating the impeller;
A motor housing that houses the motor;
A fan casing that is disposed radially outside the motor housing and forms a flow path in a gap with the motor housing;
With
On the radially outer side of the motor housing,
A plurality of first stationary blades arranged in the circumferential direction and extending in the axial direction;
A second stator blade disposed between the first stator blades adjacent in the circumferential direction and extending in the axial direction;
Is placed,
An air blower in which an upper end of the second stationary blade is disposed below an upper end of the first stationary blade and an upper side of a lower end of the first stationary blade.   The blower according to claim 1, wherein a lower end of the second stator blade is disposed below a lower end of the first stator blade.   The blower according to claim 1 or 2, wherein at least a part of the first stationary blade overlaps with the second stationary blade when viewed in the axial direction. At least a portion of the motor is in direct or indirect contact with the motor housing;
The blower according to any one of claims 1 to 3, wherein the first stationary blade and the second stationary blade are metal members.   The blower according to any one of claims 1 to 4, wherein the number of the first stationary blades is equal to the number of the second stationary blades.   The blower according to any one of claims 1 to 5, wherein a thickness of the second stator blade in a circumferential direction is thinner than a thickness of the first stator blade in a circumferential direction. At the lower end of the pressure surface of the first stationary blade, a first lower curved surface that is curved forward in the rotational direction of the impeller as it goes downward is formed.
A second lower curved surface that curves toward the front side in the rotational direction of the impeller as it goes downward is formed at the lower end of the pressure surface of the second stationary blade,
The blower device according to claim 6, wherein a curvature radius of the second lower curved surface is longer than a curvature radius of the first lower curved surface.   The blower device according to claim 7, wherein a radius of curvature of the second lower curved surface is 1.8 to 2.5 times a radius of curvature of the first lower curved surface. The first stationary blade is
An upper portion of the first stationary blade that inclines in the circumferential direction toward the rear side in the rotational direction of the impeller from the lower side toward the upper side;
A lower portion of the first stator blade, which is positioned axially lower than the upper portion of the first stator blade,
The second stationary blade is
An upper portion of the second stationary blade that inclines in the circumferential direction toward the rear side in the rotational direction of the impeller from the lower side toward the upper side;
The blower according to any one of claims 1 to 8, further comprising: a second stationary blade lower portion positioned on an axial lower side than the second stationary blade upper portion. The upper part of the first stationary blade has a first curved surface that is curved toward the rear side in the rotational direction of the impeller from the lower part of the first stationary blade,
The blower device according to claim 9, wherein the upper part of the second stationary blade has a second curved surface that is curved toward the rear side in the rotation direction of the impeller rather than the lower part of the second stationary blade.   The circumferential length between the rear end in the rotation direction of the impeller in the first stator blade and the front end in the rotation direction of the impeller on the pressure surface of the upper portion of the first stator blade is the rotation of the impeller in the second stator blade. The blower according to claim 10, wherein the blower is longer than a circumferential length between a direction rear end and a rotation direction front end of the impeller on a pressure surface of the upper part of the second stationary blade.   The blower according to claim 10 or 11, wherein a radius of curvature of the pressure surface in the first curved surface is smaller than a radius of curvature of the pressure surface in the second curved surface.   The blower device according to claim 12, wherein a radius of curvature of the pressure surface in the second curved surface is 1.8 to 2.2 times a radius of curvature of the pressure surface in the first curved surface.   The lower part of the second stationary blade has an extending surface extending in the axial direction on the pressure surface side at a position below the lower end of the first stationary blade, according to any one of claims 9 to 13. The blower described. The first stationary blade lower portion has a first surface extending in the axial direction on the pressure surface side, and the second stationary blade lower portion has a second surface extending in the axial direction on the pressure surface side,
The blower device according to claim 14, wherein an axial length of the first surface is shorter than an axial length of the second surface.   The blower device according to claim 15, wherein an axial length of the second surface is 0.2 to 0.65 times an axial length of the lower portion of the second stationary blade.   17. The axial length of the upper portion of the second stationary blade is from 0.2 to 0.5 times the axial length of the second stationary blade. 17. Blower. In a region where the lower part of the first stationary blade and the lower part of the second stationary blade overlap in the circumferential direction,
Of the first stationary blades adjacent in the circumferential direction, the circumferential width between the first stationary blade and the second stationary blade arranged on the rear side in the rotation direction of the impeller is:
18. The structure according to claim 9, wherein the circumferential width between the first stator blade and the second stator blade arranged on the front side in the rotational direction of the impeller is 1.1 to 1.3 times. The air blower of any one of these.   In the region where the first stationary blade and the second stationary blade overlap in the circumferential direction, the circumferential center of the second stationary blade is disposed at the circumferential center between the first stationary blades adjacent in the circumferential direction. The blower according to any one of claims 1 to 18.   The axial length of the upper end of the first stationary blade and the upper end of the second stationary blade is shorter than the length of the circumferential gap between the upper ends of the first stationary blades adjacent in the circumferential direction. The blower according to claim 19.   The axial length of a region where the first stator blade and the second stator blade overlap in the circumferential direction is 0.5 to 0.8 times the axial length of the first stator blade. The air blower according to any one of claims 20 to 20.   The blower according to any one of claims 1 to 21, wherein an axial length of the second stationary blade is longer than an axial length of the first stationary blade.   The blower according to any one of claims 1 to 22, wherein the motor housing includes a vent hole that penetrates in a radial direction and communicates the flow path and the inside of the motor housing.   A vacuum cleaner provided with the air blower of any one of Claims 1-23.

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