US20220120287A1 - Electric blower - Google Patents
Electric blower Download PDFInfo
- Publication number
- US20220120287A1 US20220120287A1 US17/422,422 US201917422422A US2022120287A1 US 20220120287 A1 US20220120287 A1 US 20220120287A1 US 201917422422 A US201917422422 A US 201917422422A US 2022120287 A1 US2022120287 A1 US 2022120287A1
- Authority
- US
- United States
- Prior art keywords
- fan case
- opening
- fan
- spacer
- electric blower
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/08—Sealings
- F04D29/16—Sealings between pressure and suction sides
- F04D29/161—Sealings between pressure and suction sides especially adapted for elastic fluid pumps
- F04D29/162—Sealings between pressure and suction sides especially adapted for elastic fluid pumps of a centrifugal flow wheel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
- F04D29/4226—Fan casings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
- F04D17/08—Centrifugal pumps
- F04D17/16—Centrifugal pumps for displacing without appreciable compression
- F04D17/165—Axial entry and discharge
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/02—Selection of particular materials
- F04D29/023—Selection of particular materials especially adapted for elastic fluid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
- F04D29/4213—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps suction ports
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
- F04D29/4226—Fan casings
- F04D29/4253—Fan casings with axial entry and discharge
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/60—Mounting; Assembling; Disassembling
- F04D29/62—Mounting; Assembling; Disassembling of radial or helico-centrifugal pumps
- F04D29/624—Mounting; Assembling; Disassembling of radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
Definitions
- the present disclosure relates to an electric blower.
- Electric blowers are used in various electric apparatuses such as vacuum cleaners.
- An electric blower disposed in a vacuum cleaner employs, as a rotary fan, a centrifugal fan capable of providing a high suction pressure.
- the centrifugal fan is attached to the rotary shaft of a motor and rotates at high speed to generate a desired air pressure.
- An electric blower employing a centrifugal fan includes, for example, a motor, a centrifugal fan attached to the rotary shaft of the motor, a fan case covering the centrifugal fan, and a fan case spacer attached to the fan case (see PTL 1, for example).
- An object of the present disclosure is to provide an electric blower or the like capable of improving the airtightness between the fan case and the fan case spacer.
- an electric blower includes: a rotor that includes a rotary shaft; a centrifugal fan that includes a first opening and is attached to the rotary shaft; a fan case that includes a second opening and covers the centrifugal fan, the second opening including an opening end that is located outside an opening end of the first opening; and a fan case spacer that includes a third opening and is attached to the fan case, the third opening being in communication with the first opening.
- the fan case spacer includes: a spacer part that closes off a gap between the opening end of the first opening and the opening end of the second opening; and a cover part that extends outward from the opening end of the second opening and covers an outer surface of the fan case.
- the cover part includes a protrusion that is annular, protrudes toward the outer surface of the fan case, and surrounds the second opening.
- the protrusion is located between the opening end of the second opening and a tip part of the cover part and is in contact with the outer surface of the fan case.
- An electric blower according to the present disclosure can enhance the airtightness between the fan case and the fan case spacer, and thus the blowing efficiency of the electric blower can be improved.
- FIG. 1 is an external perspective view of an electric blower according to an exemplary embodiment.
- FIG. 2 is a cross-sectional view of the electric blower according to an exemplary embodiment.
- FIG. 3 is an exploded perspective view of a fan case spacer, a fan case, and a centrifugal fan, as the electric blower according to an exemplary embodiment is viewed from an upper direction.
- FIG. 4 is an exploded perspective view of the fan case spacer, the fan case, and the centrifugal fan, as the electric blower according to an exemplary embodiment is viewed from a lower direction.
- FIG. 5 is a perspective view of the fan case spacer of the electric blower according to an exemplary embodiment.
- FIG. 6 is an enlarged cross-sectional view of a region VI enclosed by a broken line in FIG. 2 in the electric blower according to an exemplary embodiment.
- FIG. 7 is a partially enlarged cross-sectional view of the electric blower according to an exemplary embodiment taken along a section passing through a fixing part of the fan case spacer.
- FIG. 8 is a diagram illustrating how the fan case spacer is assembled to the fan case of the electric blower according to an exemplary embodiment.
- FIG. 9 is an enlarged cross-sectional view of an electric blower of a comparative example.
- FIG. 1 is an external perspective view of electric blower 1 according to an exemplary embodiment.
- FIG. 2 is a cross-sectional view of electric blower 1 .
- FIG. 2 shows a cross section of electric blower 1 taken along a plane passing through shaft center C of rotary shaft 13 . Note that FIG. 2 only shows line drawings appearing on a cross section. Bold arrows shown in FIG. 2 each indicate a flow of air drawn into electric blower 1 .
- shaft center C extends along a vertical direction.
- centrifugal fan 20 is located above rotor 11 on the upper output shaft side, while second bearing part 17 is located below rotor 11 on the lower side opposite to the output shaft side.
- the vertical direction is defined as above for ease of understanding the following description. Therefore, the vertical direction may be different from an actual vertical direction depending on, for example, the state in which electric blower 1 is used.
- electric blower 1 in the present exemplary embodiment includes motor 10 , centrifugal fan 20 , fan case 30 , fan case spacer 40 , air guide 50 , and motor case 60 .
- Motor 10 includes rotor 11 and stator 12 .
- Centrifugal fan 20 is attached to rotary shaft 13 , which is included in motor 10 .
- Fan case 30 covers centrifugal fan 20 .
- Fan case spacer 40 is attached to fan case 30 .
- To air guide 50 the air discharged from the centrifugal fan 20 flows.
- Motor case 60 houses motor 10 .
- Motor 10 is an electric motor that causes centrifugal fan 20 to rotate.
- Motor 10 in the present exemplary embodiment is a commutator motor with a brush, and includes rotor 11 , stator 12 , rotary shaft 13 , commutator 14 , brush 15 , first bearing part 16 , and second bearing part 17 .
- Rotor 11 (rotating part) includes rotary shaft 13 .
- Rotor 11 is an inner rotor disposed inside stator 12 , as illustrated in FIG. 2 .
- rotor 11 is surrounded by stator 12 via a small air gap between rotor 11 and stator 12 .
- Rotor 11 rotates around shaft center C of rotary shaft 13 as a rotation center.
- Rotor 11 rotates as fast as, for example, 40,000 rpm.
- Rotor 11 is an armature.
- Rotor 11 includes rotor core 11 a (rotor iron core) and wound coil 11 b wound around rotor core 11 a via an insulator.
- FIG. 2 shows wound coil 11 b schematically.
- Rotor core 11 a is a magnetic body made of a magnetic material.
- rotor core 11 a is a stacked body in which multiple electromagnetic steel plates are stacked along the direction of shaft center C of rotary shaft 13 (shaft center direction).
- Rotor core 11 a includes a plurality of teeth parts protruding in a radial direction. When a current flows through wound coil 11 b , each teeth part generates a magnetic force to act on stator 12 .
- Stator 12 (stationary part), which is located to face rotor 11 , generates a magnetic force to act on rotor 11 .
- Stator 12 is disposed so as to surround rotor 11 .
- Stator 12 is configured such that N poles and S poles alternately appear in the circumferential direction on the air gap surface.
- stator 12 may be configured such that a plurality of permanent magnets is arranged in the circumferential direction, or may include a stator core having a plurality of teeth parts and a wound coil being wound around the stator core.
- Stator 12 is fixed to, for example, motor case 60 .
- Rotary shaft 13 is a shaft serving as a center around which rotor 11 rotates.
- Rotary shaft 13 extends in the longitudinal direction, which is the shaft center direction.
- Rotary shaft 13 is, for example, a metal rod.
- Rotary shaft 13 is fixed to rotor 11 .
- rotary shaft 13 is fixed to rotor core 11 a with, for example, rotary shaft 13 passing through the center of rotor core 11 a of rotor 11 .
- rotary shaft 13 is fixed to rotor core 11 a by press-fitting or shrink-fitting rotary shaft 13 into a center hole created in rotor core 11 a.
- first bearing part 16 One end of rotary shaft 13 (the end on the centrifugal fan 20 side) is supported by first bearing part 16 .
- second bearing part 17 The other end of rotary shaft 13 is supported by second bearing part 17 .
- first bearing part 16 and second bearing part 17 is, for example, a ball bearing that supports rotary shaft 13 .
- a slide bearing or some other bearing may be used as first bearing part 16 and second bearing part 17 . In this way, both ends of rotary shaft 13 are rotatably held by first bearing part 16 and second bearing part 17 .
- Centrifugal fan 20 is attached to the tip part of rotary shaft 13 .
- Commutator 14 is attached to rotary shaft 13 .
- Commutator 14 is fixed on rotary shaft 13 between rotor 11 and first bearing part 16 .
- Commutator 14 is electrically connected to wound coil 11 b included in rotor 11 , and is in sliding contact with brush 15 .
- Commutator 14 is made up of a plurality of segments insulated and isolated from each other in the rotation direction of rotary shaft 13 .
- Brush 15 is a power supply brush for supplying electric power to rotor 11 by being in contact with commutator 14 .
- Brush 15 supplies an armature current to commutator 14 by being in contact with commutator 14 .
- Brush 15 is, for example, a carbon brush.
- Brush 15 is in a long and substantially rectangular solid shape.
- Brush 15 is disposed so as to be in sliding contact with commutator 14 .
- a pair of brushes 15 is provided.
- the pair of brushes 15 is disposed to face each other across commutator 14 so as to sandwich commutator 14 .
- the inner tip of each of the pair of brushes 15 abuts on commutator 14 .
- An end face of brush 15 on the inner side (on the rotary shaft 13 side) with respect to the longitudinal direction of brush 15 is the face in contact with commutator 14 .
- Centrifugal fan 20 draws air into an outer casing (housing) made up of fan case 30 and motor case 60 .
- Centrifugal fan 20 which is attached to a predetermined part of rotary shaft 13 of motor 10 , is caused to rotate by rotation of rotary shaft 13 .
- Centrifugal fan 20 is attached to the tip part of rotary shaft 13 .
- Centrifugal fan 20 can be fixed to rotary shaft 13 by, for example, press-fitting rotary shaft 13 into a through hole formed in centrifugal fan 20 .
- centrifugal fan 20 may be pressed and held on rotary shaft 13 by tightening a fastening nut with a screw provided on the end face of rotary shaft 13 .
- Centrifugal fan 20 includes inlet 20 a (intake port) for drawing air and outlet 20 b (outtake port) for discharging the air drawn from inlet 20 a .
- Inlet 20 a of centrifugal fan 20 is a first opening.
- Inlet 20 a opens on the side opposite to the position where rotor 11 is attached to rotary shaft 13 with respect to the direction along which shaft center C extends.
- Centrifugal fan 20 includes first lateral plate 21 provided with inlet 20 a , second lateral plate 22 facing first lateral plate 21 across a predetermined gap, and a plurality of fan blades 23 put between first lateral plate 21 and second lateral plate 22 .
- First lateral plate 21 , second lateral plate 22 , and the plurality of fan blades 23 are made of, for example, a metal plate such as an aluminum plate; however, this is not restrictive.
- First lateral plate 21 is an upper plate located upstream (on the fan case 30 side).
- Inlet 20 a (first opening) provided on first lateral plate 21 faces inlet 30 a (second opening) of fan case 30 .
- Inlet 20 a is, for example, a circular through hole.
- First lateral plate 21 is in a substantially truncated cone shape.
- Inlet 20 a is provided on the top of first lateral plate 21 .
- First lateral plate 21 in such shape can be formed by drawing a circular flat plate having a through hole corresponding to inlet 20 a into a substantially truncated cone shape.
- Second lateral plate 22 is a lower plate located downstream (on the motor case 60 side). Second lateral plate 22 is a circular flat plate. A through hole is provided in a central portion of second lateral plate 22 . Rotary shaft 13 is inserted into, and fixed to, the through hole via a fan boss, a backing plate, and the like.
- Each of the plurality of fan blades 23 is a plate curved in an arc and is disposed radially.
- the plurality of fan blades 23 is disposed between first lateral plate 21 and second lateral plate 22 at equal intervals so as to be vortex-shaped.
- Each fan blade 23 is fixed to each of first lateral plate 21 and second lateral plate 22 by swaging.
- the number of fan blades 23 is six, for example; however, the number of fan blades 23 is not limited to six but may be eleven, for example.
- the space surrounded by two adjacent fan blades 23 , first lateral plate 21 , and second lateral plate 22 is an air flow path through which the air flowing from inlet 20 a into centrifugal fan 20 passes.
- the opening radially outside the air flow path is outlet 20 b .
- a plurality of the air flow paths is spirally formed along a plane normal to shaft center C of rotary shaft 13 .
- outlet 20 b opens in a direction along shaft center C of rotary shaft 13
- a plurality of outlets 20 b is formed along the circumferential direction of centrifugal fan 20 .
- Fan case 30 is a cover covering centrifugal fan 20 and air guide 50 .
- fan case 30 is a metal cover made of a metal material.
- Fan case 30 has centrifugal fan 20 and air guide 50 inside fan case 30 . In other words, centrifugal fan 20 and air guide 50 are housed in fan case 30 .
- Fan case 30 includes lid part 31 (first fan case part) that covers an upper portion of centrifugal fan 20 and air guide 50 , and side wall part 32 (second fan case part) that covers side portions of centrifugal fan 20 and air guide 50 .
- Fan case 30 is fixed to motor case 60 .
- side wall part 32 of fan case 30 is connected to an opening end of motor case 60 , whereby fan case 30 and motor case 60 are fixed to each other.
- Fan case 30 includes inlet 30 a (intake port) for drawing outside air.
- Inlet 30 a is a circular through hole provided in a central portion of lid part 31 .
- Inlet 30 a which is a second opening, of fan case 30 faces inlet 20 a , which is the first opening, of centrifugal fan 20 .
- Opening end 30 al of inlet 30 a (second opening) of fan case 30 is located outward from opening end 20 al of inlet 20 a (first opening) of centrifugal fan 20 . That is, the opening diameter of inlet 30 a of fan case 30 is larger than the opening diameter of inlet 20 a of centrifugal fan 20 .
- opening end 30 al of fan case 30 surrounds opening end 20 al of centrifugal fan 20 . Therefore, in top view, there is an annular gap between opening end 20 al of centrifugal fan 20 and opening end 30 al of fan case 30 .
- Fan case spacer 40 is attached to fan case 30 .
- An outer surface of fan case 30 includes a mounting surface on which fan case spacer 40 is mounted.
- fan case spacer 40 is mounted on lid part 31 of fan case 30 so as to surround inlet 30 a of fan case 30 . That is, the mounting surface where fan case spacer 40 is attached to fan case 30 is part of the outer surface of lid part 31 .
- Fan case spacer 40 closes off the annular gap formed between opening end 20 al of centrifugal fan 20 and opening end 30 al of fan case 30 .
- centrifugal fan 20 rotates, air flows into fan case 30 from inlet 30 a of fan case 30 .
- the pressure around outlet 20 b of centrifugal fan 20 rises, and thus a difference in air pressure is caused in the space path between first lateral plate 21 of centrifugal fan 20 and lid part 31 of fan case 30 , and a circulating flow from outlet 20 b of centrifugal fan 20 directed toward inlet 30 a of fan case 30 is going to be generated.
- the circulating can be reduced by providing fan case spacer 40 as described above.
- the pressure can be prevented from escaping by providing fan case spacer 40 .
- the blowing efficiency of electric blower 1 can be improved.
- fan case 30 can be protected by providing fan case spacer 40 .
- Fan case spacer 40 includes inlet 40 a (intake port) for drawing outside air.
- Inlet 40 a is a circular through hole provided in a central portion of fan case spacer 40 .
- Inlet 40 a which is a third opening, of fan case spacer 40 is in communication with inlet 20 a , which is the first opening, of centrifugal fan 20 .
- the opening diameter of inlet 40 a of fan case spacer 40 is approximately equal to the opening diameter of inlet 20 a of centrifugal fan 20 .
- opening end 40 al of fan case spacer 40 is substantially overlaid with opening end 20 al of centrifugal fan 20 . Note that fan case spacer 40 will be described in detail later.
- the air drawn from inlet 30 a of fan case 30 by rotation of centrifugal fan 20 is drawn from inlet 20 a of centrifugal fan 20 , blown out from outlet 20 b , and flows into air guide 50 .
- Air guide 50 has a function of rectifying the air blown out from centrifugal fan 20 and smoothly flowing the rectified air into motor case 60 .
- Air guide 50 includes a plurality of diffuser blades 51 .
- Each of the plurality of diffuser blades 51 is plate-shaped, curved in an arc, and disposed radially. Specifically, the plurality of diffuser blades 51 is placed so as to be vortex-shaped.
- Air guide 50 is made of, for example, a resin material; however, this is not restrictive, and air guide 50 may alternatively be made of a metal material.
- Motor case 60 is a casing (frame) for housing motor 10 . Specifically, motor case 60 houses rotor 11 and stator 12 . In other words, motor case 60 has rotor 11 and stator 12 inside motor case 60 .
- Motor case 60 is, for example, a metal case made of a metal material.
- Motor case 60 has a bottomed cylindrical shape with an opening.
- Motor case 60 has a bottom and a cylindrical side wall.
- Motor case 60 includes a plurality of outlets 60 a disposed in the bottom and in the side wall for blowing out the air drawn by rotation of centrifugal fan 20 .
- outlets 60 a are outtake ports for discharging the air drawn into motor case 60 by centrifugal fan 20 .
- bracket 61 is disposed so as to partially cover the opening of motor case 60 .
- bracket 61 is disposed so as to extend across the opening of motor case 60 .
- Bracket 61 has a plurality of openings provided therein. The air rectified by air guide 50 passes through the openings of bracket 61 and motor case 60 in a portion not covered by bracket 61 to flow into motor case 60 .
- Bracket 61 is made of, for example, a resin material; however, this is not restrictive, and bracket 61 may alternatively be made of a metal material.
- centrifugal fan 20 rotates to draw air from inlet 30 a of fan case 30 into fan case 30 .
- the air flows from inlet 20 a of centrifugal fan 20 into centrifugal fan 20 .
- the air drawn into centrifugal fan 20 is compressed to a high pressure by fan blades 23 of centrifugal fan 20 , and is discharged in a radial direction from outlet 20 b on the outer perimeter side of centrifugal fan 20 .
- centrifugal fan 20 The air discharged from centrifugal fan 20 is guided to side wall part 32 of fan case 30 by diffuser blades 51 of air guide 50 surrounding centrifugal fan 20 to become a swirling flow, and flows into motor case 60 .
- the swirling flow flowing into motor case 60 is then discharged to the outside of electric blower 1 from outlets 60 a of motor case 60 while cooling rotor 11 and stator 12 of motor 10 .
- FIG. 3 is an exploded perspective view of fan case spacer 40 , fan case 30 , and centrifugal fan 20 , as electric blower 1 according to an exemplary embodiment is viewed from an upper direction.
- FIG. 4 is an exploded perspective view of fan case spacer 40 , fan case 30 , and centrifugal fan 20 , as electric blower 1 according to an exemplary embodiment is viewed from a lower direction.
- FIG. 3 is an exploded perspective view of fan case spacer 40 , fan case 30 , and centrifugal fan 20 , as electric blower 1 according to an exemplary embodiment is viewed from a lower direction.
- FIG. 5 is a perspective view of fan case spacer 40 of electric blower 1 according to an exemplary embodiment.
- FIG. 6 is an enlarged cross-sectional view of a region VI enclosed by a broken line in FIG. 2 in electric blower 1 according to an exemplary embodiment.
- FIG. 7 is a partially enlarged cross-sectional view of electric blower 1 according to an exemplary embodiment taken along a section passing through fixing part 413 of fan case spacer 40 .
- fan case spacer 40 includes spacer part 410 and cover part 420 .
- Fan case spacer 40 is made of a resin material.
- fan case spacer 40 is a resin molded product in which spacer part 410 and cover part 420 are integrally formed of a resin material.
- Fan case spacer 40 is made of a thermoplastic resin because fan case spacer 40 is to be fixed to fan case 30 by ultrasonic welding.
- Fan case spacer 40 is made of, for example, acrylonitrile butadiene styrene (ABS) resin or polypropylene.
- ABS acrylonitrile butadiene styrene
- spacer part 410 is formed so as to close off the gap between opening end 20 al of inlet 20 a (first opening) of centrifugal fan 20 and opening end 30 al of inlet 30 a (second opening) of fan case 30 .
- spacer part 410 is annular in top view, and is formed so as to extend across opening end 20 al of centrifugal fan 20 and opening end 30 al of fan case 30 .
- Inlet 40 a of fan case spacer 40 is provided on spacer part 410 .
- opening end 40 al of fan case spacer 40 is provided on spacer part 410 .
- Spacer part 410 includes first connecting part 411 connected to opening end 20 al of centrifugal fan 20 and second connecting part 412 connected to opening end 30 al of fan case 30 . As illustrated in FIG. 5 , first connecting part 411 and second connecting part 412 are each formed to protrude toward centrifugal fan 20 and to be annular.
- First connecting part 411 is formed into a cylindrical shape having a small thickness, and is connected to opening end 20 al of centrifugal fan 20 . Specifically, as illustrated in FIGS. 6 and 7 , the side wall surface of first connecting part 411 is in contact with the inner surface of first lateral plate 21 of centrifugal fan 20 . Therefore, first connecting part 411 is to be in sliding contact with first lateral plate 21 of centrifugal fan 20 when centrifugal fan 20 rotates.
- Second connecting part 412 is connected to opening end 30 a 1 of fan case 30 in such a way as to enter fan case 30 deeper than lid part 31 of fan case 30 . Specifically, the side wall surface of second connecting part 412 is in contact with the side surface of lid part 31 of fan case 30 along the thickness of lid part 31 .
- fan case spacer 40 includes fixing part 413 for fixing fan case spacer 40 to fan case 30 .
- Fixing part 413 is provided on spacer part 410 .
- a plurality of fixing parts 413 is provided as part of second connecting part 412 .
- the plurality of fixing parts 413 is formed to protrude from second connecting part 412 toward centrifugal fan 20 .
- multiple fixing parts 413 are equally spaced annularly so as to surround inlet 40 a of fan case spacer 40 .
- Eight fixing parts 413 are provided.
- each fixing part 413 is flush with the side wall surface of second connecting part 412 , and is in contact with the side surface of lid part 31 of fan case 30 along the thickness of lid part 31 , as with the side wall surface of second connecting part 412 .
- Each of fixing parts 413 is a welded part welded to opening end 30 a 1 of inlet 30 a (second opening) of fan case 30 .
- Fixing parts 413 are welded to opening end 30 a 1 of fan case 30 , whereby fan case spacer 40 is fixed to opening end 30 a 1 of fan case 30 .
- Fixing parts 413 are welded to opening end 30 a 1 of fan case 30 by, for example, ultrasonic welding. That is, fixing parts 413 made of a thermoplastic resin are, by ultrasonic vibration and welding force, melted and joined to fan case 30 made of metal.
- cover part 420 extends outward from opening end 30 a 1 of inlet 30 a (second opening) of fan case 30 and covers the outer surface of fan case 30 .
- Cover part 420 is annular in top view, and is formed to extend outward along the outer surface (mounting surface) of lid part 31 of fan case 30 . Note that, as illustrated in FIG. 3 , a plurality of ribs is formed radially from inlet 40 a on the upper surface of cover part 420 .
- cover part 420 includes protrusion 421 protruding toward the outer surface of fan case 30 .
- Protrusion 421 has a tapered shape on a cross section including shaft center C.
- protrusion 421 is in a ring shape surrounding inlet (third opening) 40 a of fan case spacer 40 .
- protrusion 421 is in a ring shape surrounding inlet 30 a (second opening) of fan case 30 .
- Protrusion 421 is annular.
- protrusion 421 is located between opening end 30 a 1 of inlet 30 a of fan case 30 and tip part 422 of cover part 420 , and is in contact with the outer surface of fan case 30 .
- protrusion 421 is located between fixing part 413 , which is included in spacer part 410 , and tip part 422 of cover part 420 .
- Protrusion 421 is in contact with the mounting surface of fan case 30 on which fan case spacer 40 is mounted.
- Protrusion 421 protrudes from the inner surface (bottom surface) of a recess provided on a surface of cover part 420 , the surface being on fan case 30 side.
- Protrusion 421 is in contact with the outer surface of lid part 31 of fan case 30 .
- protrusion 421 serves as a partition that partitions the gap between cover part 420 and fan case 30 .
- Protrusion 421 protrudes from the inner surface of cover part 420 , and at least the tip of protrusion 421 reaches the outer surface of fan case 30 .
- protrusion 421 is deformed to be curved and is inclined along the outer surface of fan case 30 . Therefore, protrusion 421 can be in close contact with the outer surface of fan case 30 to come into pressure contact with the outer surface of fan case 30 . That is, protrusion 421 is in pressure contact with the outer surface of fan case 30 .
- Protrusion 421 is curved so as to extend outward from inlet 30 a of fan case 30 . In other words, protrusion 421 is deformed from the base to the tip of protrusion 421 so as to extend in a direction away from opening end 30 a 1 of fan case 30 to come into pressure contact with the outer surface of fan case 30 .
- Tip part 422 of cover part 420 includes first pressure contact surface 422 a that adheres to the outer surface of fan case 30 annularly so as to surround inlet 30 a of fan case 30 .
- First pressure contact surface 422 a is in pressure contact with the outer surface of lid part 31 of fan case 30 . That is, on first pressure contact surface 422 a , tip part 422 of cover part 420 gives a pressing force to lid part 31 of fan case 30 .
- First pressure contact surface 422 a is, for example, in an annular shape having a constant width of 0.1 mm.
- cover part 420 includes pressure contact part 423 located between opening end 30 a 1 of inlet 30 a of fan case 30 and protrusion 421 .
- Pressure contact part 423 includes second pressure contact surface 423 a that comes into pressure contact with the outer surface of fan case 30 annularly so as to surround inlet 30 a of fan case 30 .
- second pressure contact surface 423 a is in pressure contact with the outer surface of lid part 31 of fan case 30 . That is, on second pressure contact surface 423 a , pressure contact part 423 gives a pressing force to lid part 31 of fan case 30 .
- Pressure contact part 423 is a projection protruding from tip part 422 toward the outer surface of fan case 30 . As illustrated in FIG. 5 , pressure contact part 423 is in an annular shape surrounding inlet 30 a of fan case 30 .
- the top surface of pressure contact part 423 which is a projection, is a ring-shaped flat surface having a constant width. The entire top surface of pressure contact part 423 is in surface contact with the outer surface of fan case 30 . Therefore, second pressure contact surface 423 a is a ring-shaped flat surface having a constant width. Second pressure contact surface 423 a is, for example, in an annular shape having a constant width of 1.0 mm.
- pressure contact part 423 is located between opening end 30 al of fan case 30 and protrusion 421 . That is, protrusion 421 is located between pressure contact part 423 and tip part 422 of cover part 420 .
- cover part 420 of fan case spacer 40 is in pressure contact with the outer surface of fan case 30 radially outward at three parts: pressure contact part 423 , protrusion 421 , and tip part 422 .
- cover part 420 brings pressure contact part 423 , protrusion 421 , and tip part 422 into pressure contact with fan case 30 .
- FIG. 8 is a diagram illustrating how fan case spacer 40 is assembled to fan case 30 of electric blower 1 according to an exemplary embodiment.
- protrusion 421 of fan case spacer 40 is neither curved nor deformed but extends straight toward fan case 30 .
- fan case spacer 40 When fan case spacer 40 is combined with fan case 30 , fan case spacer 40 is pressed against fan case 30 such that the side walls of second connecting part 412 and fixing part 413 of fan case spacer 40 come into contact with the side surface of lid part 31 of fan case 30 along the thickness of lid part 31 .
- cover part 420 of fan case spacer 40 comes into pressure contact with the outer surface of fan case 30 at three parts: pressure contact part 423 , protrusion 421 , and tip part 422 .
- tip part 422 and pressure contact part 423 lightly come into pressure contact with the outer surface of fan case 30 to have portions in pressure contact with fan case 30 designated as first pressure contact surface 422 a and second pressure contact surface 423 a , respectively.
- protrusion 421 protrudes from a surface that is along the inner surface of cover part 420 . Therefore, when fan case spacer 40 is assembled to fan case 30 , protrusion 421 is pressed against the outer surface of fan case 30 , bent, and deformed so as to be inclined.
- the shape of protrusion 421 in cross-sectional view is substantially an acute triangle in which the radially outer surface stands straight as compared with the radially inner surface (that is, substantially an acute triangle in which the radially outer surface has a smaller inclination angle with respect to the vertical direction than the radially inner surface face). Therefore, during the process of being pressed against the outer surface of fan case 30 , protrusion 421 is curved to extend outward to be deformed into the shape as illustrated in FIG. 7 .
- fan case spacer 40 is joined to fan case 30 by ultrasonic welding. That is, fixing parts 413 made of a thermoplastic resin are, by ultrasonic vibration and welding force, melted and joined to fan case 30 made of metal. In this way, fan case spacer 40 can be joined to fan case 30 . As a result, fan case spacer 40 can be assembled to fan case 30 in the state where three parts, namely pressure contact part 423 , protrusion 421 , and tip part 422 , are in pressure contact with the outer surface of fan case 30 .
- FIG. 9 is an enlarged cross-sectional view of electric blower 1 X according to a comparative example. Note that FIG. 9 corresponds to FIG. 6 .
- electric blower 1 X of the comparative example is similar in configuration to electric blower 1 according to the above-described exemplary embodiment, except that the configuration of fan case spacer 40 X is different.
- fan case spacer 40 of electric blower 1 according to the above-described exemplary embodiment includes protrusion 421 and pressure contact part 423 disposed in cover part 420
- fan case spacer 40 X of electric blower 1 X of the comparative example has neither protrusion 421 nor pressure contact part 423 disposed in cover part 420 X.
- cover part 420 of fan case spacer 40 includes protrusion 421 that is annular, protrudes toward the outer surface of fan case 30 , and surrounds inlet 30 a , which corresponds to the second opening, of fan case 30 .
- Protrusion 421 is located between opening end 30 al of inlet 30 a , which is the second opening, of fan case 30 and tip part 422 of cover part 420 , and is in contact with the outer surface of fan case 30 .
- the recess formed in cover part 420 on a surface facing fan case 30 has space H located closer to tip part 422 than protrusion 421 and space L located closer to inlet 40 a than protrusion 421 , where space H is to have a higher pressure and space L is to have a negative pressure. Accordingly, a force causing protrusion 421 to more closely adhere to fan case 30 acts on protrusion 421 . That is, protrusion 421 serves as an adhering part (tight part) where fan case spacer 40 and fan case 30 adhere to each other. Therefore, the airtightness between fan case spacer 40 and fan case 30 can be enhanced. As a result, the blowing efficiency of electric blower 1 can be improved.
- protrusion 421 is separated from fixing part 413 for fixing fan case spacer 40 to fan case 30 , stable airtightness can be obtained.
- protrusion 421 is inclined along the outer surface of fan case 30 .
- protrusion 421 is deformed to be further tilted by a difference in air pressure between the inside and outside of fan case 30 . Accordingly, as centrifugal fan 20 rotates at higher speed to cause a greater difference in air pressure between the inside and outside of fan case 30 , protrusion 421 and fan case 30 can be in contact with each other on a wider area. Therefore, as centrifugal fan 20 rotates at higher speed, the airtightness between fan case spacer 40 and fan case 30 can be enhanced.
- protrusion 421 is in a tapered shape. Specifically, as illustrated in FIG. 8 , protrusion 421 before deformed in cross-sectional view is substantially in an acute triangular shape having an aspect ratio of 2 or higher. Therefore, as illustrated in FIGS. 6 and 7 , protrusion 421 can be easily curved when pressed against fan case 30 .
- protrusion 421 may be made of a resin material different from the material of parts of fan case spacer 40 other than protrusion 421 .
- protrusion 421 may be made of an elastomer having elasticity of rubber softer than cover part 420 .
- protrusion 421 can be easily deformed when pressed against the outer surface of fan case 30 .
- parts of fan case spacer 40 other than protrusion 421 may be made of an ABS resin, and protrusion 421 may be made of a silicone resin or the like having rubber elasticity.
- protrusion 421 and parts other than protrusion 421 can be produced by two-color molding.
- tip part 422 of cover part 420 includes first pressure contact surface 422 a that comes into close contact with the outer surface of fan case 30 annularly so as to surround inlet 30 a , which corresponds to the second opening, of fan case 30 .
- This configuration allows two parts, namely protrusion 421 and tip part 422 , to serve as adhering parts where fan case spacer 40 and fan case 30 adhere to each other.
- two parts namely protrusion 421 and tip part 422
- the airtightness between fan case spacer 40 and fan case 30 is likely to vary depending on the degree of adherence (the state of pressure contact) between fan case spacer 40 and fan case 30 , which may cause unstable airtightness between fan case spacer 40 and fan case 30 .
- the two parts namely protrusion 421 and tip parts 422 , serve as adhering parts where fan case spacer 40 and fan case 30 adhere to each other.
- variations in the airtightness between fan case spacer 40 and fan case 30 can be significantly reduced, as compared with the case where there is only one adhering part.
- variations in the airtightness between fan case spacer 40 and fan case 30 can be significantly reduced.
- high and stable airtightness between fan case spacer 40 and fan case 30 can be easily obtained. Therefore, the blowing efficiency of electric blower 1 can be kept high.
- cover part 420 includes pressure contact part 423 located between opening end 30 a 1 of inlet 30 a , which is the second opening, of fan case 30 and protrusion 421 .
- Pressure contact part 423 includes second pressure contact surface 423 a that comes into pressure contact with the outer surface of fan case 30 annularly so as to surround inlet 30 a , which corresponds to the second opening, of fan case 30 .
- This configuration additionally allows pressure contact part 423 to serve as an adhering part where fan case spacer 40 and fan case 30 adhere to each other. Therefore, high and stable airtightness between fan case spacer 40 and fan case 30 can be obtained more easily.
- the three parts namely protrusion 421 , tip part 422 , and pressure contact part 423 , serve as adhering parts
- variations in airtightness between fan case spacer 40 and fan case 30 can be much more significantly reduced.
- protrusion 421 as a third adhering part in addition to a first adhering part on tip part 422 and a second adhering part on pressure contact part 423
- variations in the airtightness between fan case spacer 40 and fan case 30 can be much more significantly reduced.
- high and stable airtightness between fan case spacer 40 and fan case 30 can be more easily obtained. Therefore, the blowing efficiency of electric blower 1 can be kept high more easily.
- fan case spacer 40 includes fixing part 413 for fixing fan case spacer 40 to fan case 30 .
- This configuration makes it easy to fix fan case spacer 40 to fan case 30 .
- fixing part 413 separately from the adhering parts on protrusion 421 , tip part 422 , and pressure contact part 423 , it is ensured that fixing part 413 fixes fan case spacer 40 to fan case 30 and the adhering parts obtain stable airtightness between fan case spacer 40 and fan case 30 .
- fixing part 413 is welded to opening end 30 al of inlet 30 a , which is the second opening, of fan case 30 .
- fixing part 413 is allowed to be joined to opening end 30 al of fan case 30 .
- fixing part (welded part) 413 is welded to opening end 30 al of inlet 30 a , which is the second opening, of fan case 30 by ultrasonic welding.
- fixing part 413 is preferably made of a thermoplastic resin.
- fixing part 413 can be melted by ultrasonic vibration and welding force and joined to opening end 30 al of fan case 30 .
- electric blower 1 of the present exemplary embodiment includes: rotor 11 that includes rotary shaft 13 ; centrifugal fan 20 that includes inlet 20 a and is attached to rotary shaft 13 , inlet 20 a being a first opening; fan case 30 that includes inlet 30 a and covers centrifugal fan 20 , inlet 30 a being a second opening whose opening end 30 a 1 is located outside opening end 20 a 1 of inlet 20 a , which is the first opening; and fan case spacer 40 that includes inlet 40 a and is attached to fan case 30 , inlet 40 a being a third opening in communication with inlet 20 a , which is the first opening.
- Fan case spacer 40 includes: spacer part 410 that closes off the gap between opening end 20 a 1 of inlet 20 a , which is the first opening, and opening end 30 a 1 of inlet 30 a , which is the second opening; and cover part 420 that extends outward from opening end 30 a 1 of inlet 30 a , which is the second opening, and covers the outer surface of fan case 30 .
- Cover part 420 includes a protrusion that is annular, protrudes toward the outer surface of fan case 30 and surrounds inlet 30 a , which is the second opening.
- Protrusion 421 is located between opening end 30 a 1 of inlet 30 a , which is the second opening, and tip part 422 of cover part 420 , and is in contact with the outer surface of fan case 30 .
- motor 10 employed in electric blower 1 ; however, motor 10 is not limited thereto.
- Motor 10 may be a brushless motor or the like.
- Electric blower 1 may be used for a vacuum cleaner, an air towel, or the like. Electric blower 1 may be applied not only to a vacuum cleaner or an air towel but also to equipment for cars, and to other household appliances or industrial equipment.
- the technology of the present disclosure can be used for various electric apparatuses in which an electric blower is used.
- the technology of the present disclosure is particularly useful for an electric blower disposed in a vacuum cleaner or the like in which a centrifugal fan is rotated at high speed.
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Abstract
An electric blower includes: a rotor that includes a rotary shaft; a centrifugal fan that includes a first opening and is attached to the rotary shaft; a fan case that includes a second opening and covers the centrifugal fan, the second opening including an opening end that is located outside an opening end of the first opening; and a fan case spacer that includes a third opening and is attached to the fan case, the third opening being in communication with the first opening. The fan case spacer includes: a spacer part that closes off a gap between the opening end of the first opening and the opening end of the second opening; and a cover part that extends outward from the opening end of the second opening and covers an outer surface of the fan case. The cover part includes a protrusion that is annular, protrudes toward the outer surface of the fan case, and surrounds the second opening. The protrusion is located between the opening end of the second opening and a tip part of the cover part and is in contact with the outer surface of the fan case.
Description
- The present disclosure relates to an electric blower.
- Electric blowers are used in various electric apparatuses such as vacuum cleaners. An electric blower disposed in a vacuum cleaner employs, as a rotary fan, a centrifugal fan capable of providing a high suction pressure. The centrifugal fan is attached to the rotary shaft of a motor and rotates at high speed to generate a desired air pressure.
- An electric blower employing a centrifugal fan includes, for example, a motor, a centrifugal fan attached to the rotary shaft of the motor, a fan case covering the centrifugal fan, and a fan case spacer attached to the fan case (see
PTL 1, for example). - In order to improve the blowing efficiency of the electric blower, it is important to secure airtightness between the fan case and the fan case spacer. However, conventional electric blowers fail to sufficiently secure airtightness between the fan case and the fan case spacer, leading to a decrease in the blowing efficiency.
- PTL 1: Unexamined Japanese Patent Publication No. 2008-180165
- The present disclosure has been made in order to solve such problem. An object of the present disclosure is to provide an electric blower or the like capable of improving the airtightness between the fan case and the fan case spacer.
- To achieve the above object, an electric blower according to one aspect of the present disclosure includes: a rotor that includes a rotary shaft; a centrifugal fan that includes a first opening and is attached to the rotary shaft; a fan case that includes a second opening and covers the centrifugal fan, the second opening including an opening end that is located outside an opening end of the first opening; and a fan case spacer that includes a third opening and is attached to the fan case, the third opening being in communication with the first opening. The fan case spacer includes: a spacer part that closes off a gap between the opening end of the first opening and the opening end of the second opening; and a cover part that extends outward from the opening end of the second opening and covers an outer surface of the fan case. The cover part includes a protrusion that is annular, protrudes toward the outer surface of the fan case, and surrounds the second opening. The protrusion is located between the opening end of the second opening and a tip part of the cover part and is in contact with the outer surface of the fan case.
- An electric blower according to the present disclosure can enhance the airtightness between the fan case and the fan case spacer, and thus the blowing efficiency of the electric blower can be improved.
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FIG. 1 is an external perspective view of an electric blower according to an exemplary embodiment. -
FIG. 2 is a cross-sectional view of the electric blower according to an exemplary embodiment. -
FIG. 3 is an exploded perspective view of a fan case spacer, a fan case, and a centrifugal fan, as the electric blower according to an exemplary embodiment is viewed from an upper direction. -
FIG. 4 is an exploded perspective view of the fan case spacer, the fan case, and the centrifugal fan, as the electric blower according to an exemplary embodiment is viewed from a lower direction. -
FIG. 5 is a perspective view of the fan case spacer of the electric blower according to an exemplary embodiment. -
FIG. 6 is an enlarged cross-sectional view of a region VI enclosed by a broken line inFIG. 2 in the electric blower according to an exemplary embodiment. -
FIG. 7 is a partially enlarged cross-sectional view of the electric blower according to an exemplary embodiment taken along a section passing through a fixing part of the fan case spacer. -
FIG. 8 is a diagram illustrating how the fan case spacer is assembled to the fan case of the electric blower according to an exemplary embodiment. -
FIG. 9 is an enlarged cross-sectional view of an electric blower of a comparative example. - An exemplary embodiment of the present disclosure will now be described with reference to the drawings. Any exemplary embodiment described below illustrates a specific example of the present disclosure. Accordingly, numerical values, shapes, materials, components, arranged positions and connection forms of the components, etc., to be used in the following exemplary embodiment are illustrative and are not to limit the scope of the present disclosure. Therefore, those components introduced in the following exemplary embodiment that are not recited in the independent claim(s) representing the most superordinate concept of the present disclosure are illustrated herein as optional components.
- Note that each drawing shows a schematic view that may not necessarily be precise illustration. Furthermore, the same reference numerals are given to substantially the same components in individual figures, and duplicate descriptions are omitted or simplified.
- First, the following describes an overall configuration of
electric blower 1 according to an exemplary embodiment with reference toFIGS. 1 and 2 .FIG. 1 is an external perspective view ofelectric blower 1 according to an exemplary embodiment.FIG. 2 is a cross-sectional view ofelectric blower 1.FIG. 2 shows a cross section ofelectric blower 1 taken along a plane passing through shaft center C of rotary shaft 13. Note thatFIG. 2 only shows line drawings appearing on a cross section. Bold arrows shown inFIG. 2 each indicate a flow of air drawn intoelectric blower 1. - For convenience, the description below assumes that shaft center C extends along a vertical direction. Specifically, in
FIG. 2 , with respect to the direction in which shaft center C extends, it is assumed thatcentrifugal fan 20 is located aboverotor 11 on the upper output shaft side, while second bearing part 17 is located belowrotor 11 on the lower side opposite to the output shaft side. The vertical direction is defined as above for ease of understanding the following description. Therefore, the vertical direction may be different from an actual vertical direction depending on, for example, the state in whichelectric blower 1 is used. - As illustrated in
FIGS. 1 and 2 ,electric blower 1 in the present exemplary embodiment includesmotor 10,centrifugal fan 20,fan case 30,fan case spacer 40,air guide 50, andmotor case 60.Motor 10 includesrotor 11 andstator 12.Centrifugal fan 20 is attached to rotary shaft 13, which is included inmotor 10.Fan case 30 coverscentrifugal fan 20.Fan case spacer 40 is attached tofan case 30. Toair guide 50, the air discharged from thecentrifugal fan 20 flows.Motor case 60houses motor 10. -
Motor 10 is an electric motor that causescentrifugal fan 20 to rotate.Motor 10 in the present exemplary embodiment is a commutator motor with a brush, and includesrotor 11,stator 12, rotary shaft 13, commutator 14, brush 15, first bearingpart 16, and second bearing part 17. - Rotor 11 (rotating part) includes rotary shaft 13.
Rotor 11 is an inner rotor disposed insidestator 12, as illustrated inFIG. 2 . Specifically,rotor 11 is surrounded bystator 12 via a small air gap betweenrotor 11 andstator 12.Rotor 11 rotates around shaft center C of rotary shaft 13 as a rotation center.Rotor 11 rotates as fast as, for example, 40,000 rpm. -
Rotor 11 is an armature.Rotor 11 includesrotor core 11 a (rotor iron core) andwound coil 11 b wound aroundrotor core 11 a via an insulator. Note thatFIG. 2 showswound coil 11 b schematically.Rotor core 11 a is a magnetic body made of a magnetic material. For example,rotor core 11 a is a stacked body in which multiple electromagnetic steel plates are stacked along the direction of shaft center C of rotary shaft 13 (shaft center direction).Rotor core 11 a includes a plurality of teeth parts protruding in a radial direction. When a current flows throughwound coil 11 b, each teeth part generates a magnetic force to act onstator 12. - Stator 12 (stationary part), which is located to face
rotor 11, generates a magnetic force to act onrotor 11.Stator 12 is disposed so as to surroundrotor 11.Stator 12 is configured such that N poles and S poles alternately appear in the circumferential direction on the air gap surface. In this case,stator 12 may be configured such that a plurality of permanent magnets is arranged in the circumferential direction, or may include a stator core having a plurality of teeth parts and a wound coil being wound around the stator core.Stator 12 is fixed to, for example,motor case 60. - Rotary shaft 13 is a shaft serving as a center around which
rotor 11 rotates. Rotary shaft 13 extends in the longitudinal direction, which is the shaft center direction. Rotary shaft 13 is, for example, a metal rod. Rotary shaft 13 is fixed torotor 11. Specifically, rotary shaft 13 is fixed torotor core 11 a with, for example, rotary shaft 13 passing through the center ofrotor core 11 a ofrotor 11. For example, rotary shaft 13 is fixed torotor core 11 a by press-fitting or shrink-fitting rotary shaft 13 into a center hole created inrotor core 11 a. - One end of rotary shaft 13 (the end on the
centrifugal fan 20 side) is supported by first bearingpart 16. The other end of rotary shaft 13 is supported by second bearing part 17. Each of first bearingpart 16 and second bearing part 17 is, for example, a ball bearing that supports rotary shaft 13. A slide bearing or some other bearing may be used as first bearingpart 16 and second bearing part 17. In this way, both ends of rotary shaft 13 are rotatably held by first bearingpart 16 and second bearing part 17. - One end of rotary shaft 13 protrudes from first bearing
part 16.Centrifugal fan 20 is attached to the tip part of rotary shaft 13. - Commutator 14 is attached to rotary shaft 13. Commutator 14 is fixed on rotary shaft 13 between
rotor 11 and first bearingpart 16. Commutator 14 is electrically connected to woundcoil 11 b included inrotor 11, and is in sliding contact with brush 15. Commutator 14 is made up of a plurality of segments insulated and isolated from each other in the rotation direction of rotary shaft 13. - Brush 15 is a power supply brush for supplying electric power to
rotor 11 by being in contact with commutator 14. Brush 15 supplies an armature current to commutator 14 by being in contact with commutator 14. Brush 15 is, for example, a carbon brush. Brush 15 is in a long and substantially rectangular solid shape. - Brush 15 is disposed so as to be in sliding contact with commutator 14. A pair of brushes 15 is provided. The pair of brushes 15 is disposed to face each other across commutator 14 so as to sandwich commutator 14. Specifically, the inner tip of each of the pair of brushes 15 abuts on commutator 14. An end face of brush 15 on the inner side (on the rotary shaft 13 side) with respect to the longitudinal direction of brush 15 is the face in contact with commutator 14.
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Centrifugal fan 20 draws air into an outer casing (housing) made up offan case 30 andmotor case 60.Centrifugal fan 20, which is attached to a predetermined part of rotary shaft 13 ofmotor 10, is caused to rotate by rotation of rotary shaft 13.Centrifugal fan 20 is attached to the tip part of rotary shaft 13.Centrifugal fan 20 can be fixed to rotary shaft 13 by, for example, press-fitting rotary shaft 13 into a through hole formed incentrifugal fan 20. Alternatively,centrifugal fan 20 may be pressed and held on rotary shaft 13 by tightening a fastening nut with a screw provided on the end face of rotary shaft 13. -
Centrifugal fan 20 includesinlet 20 a (intake port) for drawing air andoutlet 20 b (outtake port) for discharging the air drawn frominlet 20 a.Inlet 20 a ofcentrifugal fan 20 is a first opening.Inlet 20 a opens on the side opposite to the position whererotor 11 is attached to rotary shaft 13 with respect to the direction along which shaft center C extends. -
Centrifugal fan 20 includes firstlateral plate 21 provided withinlet 20 a, secondlateral plate 22 facing firstlateral plate 21 across a predetermined gap, and a plurality offan blades 23 put between firstlateral plate 21 and secondlateral plate 22. Firstlateral plate 21, secondlateral plate 22, and the plurality offan blades 23 are made of, for example, a metal plate such as an aluminum plate; however, this is not restrictive. - First
lateral plate 21 is an upper plate located upstream (on thefan case 30 side).Inlet 20 a (first opening) provided on firstlateral plate 21 facesinlet 30 a (second opening) offan case 30.Inlet 20 a is, for example, a circular through hole. Firstlateral plate 21 is in a substantially truncated cone shape.Inlet 20 a is provided on the top of firstlateral plate 21. Firstlateral plate 21 in such shape can be formed by drawing a circular flat plate having a through hole corresponding toinlet 20 a into a substantially truncated cone shape. - Second
lateral plate 22 is a lower plate located downstream (on themotor case 60 side). Secondlateral plate 22 is a circular flat plate. A through hole is provided in a central portion of secondlateral plate 22. Rotary shaft 13 is inserted into, and fixed to, the through hole via a fan boss, a backing plate, and the like. - Each of the plurality of
fan blades 23 is a plate curved in an arc and is disposed radially. The plurality offan blades 23 is disposed between firstlateral plate 21 and secondlateral plate 22 at equal intervals so as to be vortex-shaped. Eachfan blade 23 is fixed to each of firstlateral plate 21 and secondlateral plate 22 by swaging. The number offan blades 23 is six, for example; however, the number offan blades 23 is not limited to six but may be eleven, for example. - The space surrounded by two
adjacent fan blades 23, firstlateral plate 21, and secondlateral plate 22 is an air flow path through which the air flowing frominlet 20 a intocentrifugal fan 20 passes. The opening radially outside the air flow path isoutlet 20 b. A plurality of the air flow paths is spirally formed along a plane normal to shaft center C of rotary shaft 13. In other words,outlet 20 b opens in a direction along shaft center C of rotary shaft 13, and a plurality ofoutlets 20 b is formed along the circumferential direction ofcentrifugal fan 20. -
Fan case 30 is a cover coveringcentrifugal fan 20 andair guide 50. Specifically,fan case 30 is a metal cover made of a metal material.Fan case 30 hascentrifugal fan 20 andair guide 50 insidefan case 30. In other words,centrifugal fan 20 andair guide 50 are housed infan case 30. -
Fan case 30 includes lid part 31 (first fan case part) that covers an upper portion ofcentrifugal fan 20 andair guide 50, and side wall part 32 (second fan case part) that covers side portions ofcentrifugal fan 20 andair guide 50. -
Fan case 30 is fixed tomotor case 60. Specifically,side wall part 32 offan case 30 is connected to an opening end ofmotor case 60, wherebyfan case 30 andmotor case 60 are fixed to each other. -
Fan case 30 includesinlet 30 a (intake port) for drawing outside air.Inlet 30 a is a circular through hole provided in a central portion oflid part 31.Inlet 30 a, which is a second opening, offan case 30 facesinlet 20 a, which is the first opening, ofcentrifugal fan 20. - Opening
end 30 al ofinlet 30 a (second opening) offan case 30 is located outward from openingend 20 al ofinlet 20 a (first opening) ofcentrifugal fan 20. That is, the opening diameter ofinlet 30 a offan case 30 is larger than the opening diameter ofinlet 20 a ofcentrifugal fan 20. In top view, openingend 30 al offan case 30 surrounds openingend 20 al ofcentrifugal fan 20. Therefore, in top view, there is an annular gap between openingend 20 al ofcentrifugal fan 20 and openingend 30 al offan case 30. -
Fan case spacer 40 is attached tofan case 30. An outer surface offan case 30 includes a mounting surface on whichfan case spacer 40 is mounted. Specifically,fan case spacer 40 is mounted onlid part 31 offan case 30 so as to surroundinlet 30 a offan case 30. That is, the mounting surface wherefan case spacer 40 is attached tofan case 30 is part of the outer surface oflid part 31. -
Fan case spacer 40 closes off the annular gap formed between openingend 20 al ofcentrifugal fan 20 and openingend 30 al offan case 30. Whencentrifugal fan 20 rotates, air flows intofan case 30 frominlet 30 a offan case 30. At the same time, the pressure aroundoutlet 20 b ofcentrifugal fan 20 rises, and thus a difference in air pressure is caused in the space path between firstlateral plate 21 ofcentrifugal fan 20 andlid part 31 offan case 30, and a circulating flow fromoutlet 20 b ofcentrifugal fan 20 directed towardinlet 30 a offan case 30 is going to be generated. However, the circulating can be reduced by providingfan case spacer 40 as described above. That is, the pressure can be prevented from escaping by providingfan case spacer 40. Compared with the case wherefan case spacer 40 is not provided, the blowing efficiency ofelectric blower 1 can be improved. In addition,fan case 30 can be protected by providingfan case spacer 40. -
Fan case spacer 40 includesinlet 40 a (intake port) for drawing outside air.Inlet 40 a is a circular through hole provided in a central portion offan case spacer 40.Inlet 40 a, which is a third opening, offan case spacer 40 is in communication withinlet 20 a, which is the first opening, ofcentrifugal fan 20. The opening diameter ofinlet 40 a offan case spacer 40 is approximately equal to the opening diameter ofinlet 20 a ofcentrifugal fan 20. In top view, openingend 40 al offan case spacer 40 is substantially overlaid with openingend 20 al ofcentrifugal fan 20. Note thatfan case spacer 40 will be described in detail later. - The air drawn from
inlet 30 a offan case 30 by rotation ofcentrifugal fan 20 is drawn frominlet 20 a ofcentrifugal fan 20, blown out fromoutlet 20 b, and flows intoair guide 50. -
Air guide 50 has a function of rectifying the air blown out fromcentrifugal fan 20 and smoothly flowing the rectified air intomotor case 60.Air guide 50 includes a plurality ofdiffuser blades 51. Each of the plurality ofdiffuser blades 51 is plate-shaped, curved in an arc, and disposed radially. Specifically, the plurality ofdiffuser blades 51 is placed so as to be vortex-shaped.Air guide 50 is made of, for example, a resin material; however, this is not restrictive, andair guide 50 may alternatively be made of a metal material. -
Motor case 60 is a casing (frame) forhousing motor 10. Specifically,motor case 60houses rotor 11 andstator 12. In other words,motor case 60 hasrotor 11 andstator 12 insidemotor case 60.Motor case 60 is, for example, a metal case made of a metal material. -
Motor case 60 has a bottomed cylindrical shape with an opening.Motor case 60 has a bottom and a cylindrical side wall.Motor case 60 includes a plurality ofoutlets 60 a disposed in the bottom and in the side wall for blowing out the air drawn by rotation ofcentrifugal fan 20. In other words,outlets 60 a are outtake ports for discharging the air drawn intomotor case 60 bycentrifugal fan 20. - Furthermore,
bracket 61 is disposed so as to partially cover the opening ofmotor case 60. For example,bracket 61 is disposed so as to extend across the opening ofmotor case 60.Bracket 61 has a plurality of openings provided therein. The air rectified byair guide 50 passes through the openings ofbracket 61 andmotor case 60 in a portion not covered bybracket 61 to flow intomotor case 60.Bracket 61 is made of, for example, a resin material; however, this is not restrictive, andbracket 61 may alternatively be made of a metal material. - In
electric blower 1 configured as described above, whenrotor 11 ofmotor 10 rotates,centrifugal fan 20 rotates to draw air frominlet 30 a offan case 30 intofan case 30. As a result, the air flows frominlet 20 a ofcentrifugal fan 20 intocentrifugal fan 20. The air drawn intocentrifugal fan 20 is compressed to a high pressure byfan blades 23 ofcentrifugal fan 20, and is discharged in a radial direction fromoutlet 20 b on the outer perimeter side ofcentrifugal fan 20. The air discharged fromcentrifugal fan 20 is guided toside wall part 32 offan case 30 bydiffuser blades 51 ofair guide 50 surroundingcentrifugal fan 20 to become a swirling flow, and flows intomotor case 60. The swirling flow flowing intomotor case 60 is then discharged to the outside ofelectric blower 1 fromoutlets 60 a ofmotor case 60 while coolingrotor 11 andstator 12 ofmotor 10. - With reference to
FIGS. 3 to 7 , the following describes in detail a configuration offan case spacer 40, which is used inelectric blower 1 according to the present exemplary embodiment, the description including connection relationships amongfan case spacer 40,fan case 30, andcentrifugal fan 20.FIG. 3 is an exploded perspective view offan case spacer 40,fan case 30, andcentrifugal fan 20, aselectric blower 1 according to an exemplary embodiment is viewed from an upper direction.FIG. 4 is an exploded perspective view offan case spacer 40,fan case 30, andcentrifugal fan 20, aselectric blower 1 according to an exemplary embodiment is viewed from a lower direction.FIG. 5 is a perspective view of fan case spacer 40 ofelectric blower 1 according to an exemplary embodiment.FIG. 6 is an enlarged cross-sectional view of a region VI enclosed by a broken line inFIG. 2 inelectric blower 1 according to an exemplary embodiment.FIG. 7 is a partially enlarged cross-sectional view ofelectric blower 1 according to an exemplary embodiment taken along a section passing through fixingpart 413 offan case spacer 40. - As illustrated in
FIGS. 3 to 7 ,fan case spacer 40 includesspacer part 410 and coverpart 420.Fan case spacer 40 is made of a resin material. Specifically,fan case spacer 40 is a resin molded product in which spacerpart 410 and coverpart 420 are integrally formed of a resin material.Fan case spacer 40 is made of a thermoplastic resin becausefan case spacer 40 is to be fixed tofan case 30 by ultrasonic welding.Fan case spacer 40 is made of, for example, acrylonitrile butadiene styrene (ABS) resin or polypropylene. - As illustrated in
FIGS. 6 and 7 ,spacer part 410 is formed so as to close off the gap between openingend 20 al ofinlet 20 a (first opening) ofcentrifugal fan 20 and openingend 30 al ofinlet 30 a (second opening) offan case 30. Specifically,spacer part 410 is annular in top view, and is formed so as to extend across openingend 20 al ofcentrifugal fan 20 and openingend 30 al offan case 30.Inlet 40 a offan case spacer 40 is provided onspacer part 410. Accordingly, openingend 40 al offan case spacer 40 is provided onspacer part 410. -
Spacer part 410 includes first connectingpart 411 connected to openingend 20 al ofcentrifugal fan 20 and second connectingpart 412 connected to openingend 30 al offan case 30. As illustrated inFIG. 5 , first connectingpart 411 and second connectingpart 412 are each formed to protrude towardcentrifugal fan 20 and to be annular. - First connecting
part 411 is formed into a cylindrical shape having a small thickness, and is connected to openingend 20 al ofcentrifugal fan 20. Specifically, as illustrated inFIGS. 6 and 7 , the side wall surface of first connectingpart 411 is in contact with the inner surface of firstlateral plate 21 ofcentrifugal fan 20. Therefore, first connectingpart 411 is to be in sliding contact with firstlateral plate 21 ofcentrifugal fan 20 whencentrifugal fan 20 rotates. Second connectingpart 412 is connected to openingend 30 a 1 offan case 30 in such a way as to enterfan case 30 deeper thanlid part 31 offan case 30. Specifically, the side wall surface of second connectingpart 412 is in contact with the side surface oflid part 31 offan case 30 along the thickness oflid part 31. - As illustrated in
FIGS. 5 and 7 ,fan case spacer 40 includes fixingpart 413 for fixing fan case spacer 40 tofan case 30. Fixingpart 413 is provided onspacer part 410. Specifically, a plurality of fixingparts 413 is provided as part of second connectingpart 412. The plurality of fixingparts 413 is formed to protrude from second connectingpart 412 towardcentrifugal fan 20. Specifically, as illustrated inFIG. 5 , multiple fixingparts 413 are equally spaced annularly so as to surroundinlet 40 a offan case spacer 40. Eight fixingparts 413 are provided. The side wall surface of each fixingpart 413 is flush with the side wall surface of second connectingpart 412, and is in contact with the side surface oflid part 31 offan case 30 along the thickness oflid part 31, as with the side wall surface of second connectingpart 412. - Each of fixing
parts 413 is a welded part welded to openingend 30 a 1 ofinlet 30 a (second opening) offan case 30. Fixingparts 413 are welded to openingend 30 a 1 offan case 30, wherebyfan case spacer 40 is fixed to openingend 30 a 1 offan case 30. Fixingparts 413 are welded to openingend 30 a 1 offan case 30 by, for example, ultrasonic welding. That is, fixingparts 413 made of a thermoplastic resin are, by ultrasonic vibration and welding force, melted and joined tofan case 30 made of metal. - As illustrated in
FIGS. 6 and 7 , coverpart 420 extends outward from openingend 30 a 1 ofinlet 30 a (second opening) offan case 30 and covers the outer surface offan case 30. Coverpart 420 is annular in top view, and is formed to extend outward along the outer surface (mounting surface) oflid part 31 offan case 30. Note that, as illustrated inFIG. 3 , a plurality of ribs is formed radially frominlet 40 a on the upper surface ofcover part 420. - As illustrated in
FIGS. 6 and 7 , coverpart 420 includesprotrusion 421 protruding toward the outer surface offan case 30.Protrusion 421 has a tapered shape on a cross section including shaft center C. As illustrated inFIG. 5 ,protrusion 421 is in a ring shape surrounding inlet (third opening) 40 a offan case spacer 40. Accordingly,protrusion 421 is in a ringshape surrounding inlet 30 a (second opening) offan case 30.Protrusion 421 is annular. - As illustrated in
FIGS. 6 and 7 ,protrusion 421 is located between openingend 30 a 1 ofinlet 30 a offan case 30 andtip part 422 ofcover part 420, and is in contact with the outer surface offan case 30. Specifically,protrusion 421 is located between fixingpart 413, which is included inspacer part 410, and tippart 422 ofcover part 420.Protrusion 421 is in contact with the mounting surface offan case 30 on whichfan case spacer 40 is mounted.Protrusion 421 protrudes from the inner surface (bottom surface) of a recess provided on a surface ofcover part 420, the surface being onfan case 30 side.Protrusion 421 is in contact with the outer surface oflid part 31 offan case 30. In other words,protrusion 421 serves as a partition that partitions the gap betweencover part 420 andfan case 30. -
Protrusion 421 protrudes from the inner surface ofcover part 420, and at least the tip ofprotrusion 421 reaches the outer surface offan case 30. Specifically,protrusion 421 is deformed to be curved and is inclined along the outer surface offan case 30. Therefore,protrusion 421 can be in close contact with the outer surface offan case 30 to come into pressure contact with the outer surface offan case 30. That is,protrusion 421 is in pressure contact with the outer surface offan case 30.Protrusion 421 is curved so as to extend outward frominlet 30 a offan case 30. In other words,protrusion 421 is deformed from the base to the tip ofprotrusion 421 so as to extend in a direction away from openingend 30 a 1 offan case 30 to come into pressure contact with the outer surface offan case 30. -
Tip part 422 ofcover part 420 includes firstpressure contact surface 422 a that adheres to the outer surface offan case 30 annularly so as to surroundinlet 30 a offan case 30. Firstpressure contact surface 422 a is in pressure contact with the outer surface oflid part 31 offan case 30. That is, on firstpressure contact surface 422 a,tip part 422 ofcover part 420 gives a pressing force tolid part 31 offan case 30. Firstpressure contact surface 422 a is, for example, in an annular shape having a constant width of 0.1 mm. - Furthermore, cover
part 420 includespressure contact part 423 located between openingend 30 a 1 ofinlet 30 a offan case 30 andprotrusion 421.Pressure contact part 423 includes secondpressure contact surface 423 a that comes into pressure contact with the outer surface offan case 30 annularly so as to surroundinlet 30 a offan case 30. As with firstpressure contact surface 422 a, secondpressure contact surface 423 a is in pressure contact with the outer surface oflid part 31 offan case 30. That is, on secondpressure contact surface 423 a,pressure contact part 423 gives a pressing force tolid part 31 offan case 30. -
Pressure contact part 423 is a projection protruding fromtip part 422 toward the outer surface offan case 30. As illustrated inFIG. 5 ,pressure contact part 423 is in an annularshape surrounding inlet 30 a offan case 30. The top surface ofpressure contact part 423, which is a projection, is a ring-shaped flat surface having a constant width. The entire top surface ofpressure contact part 423 is in surface contact with the outer surface offan case 30. Therefore, secondpressure contact surface 423 a is a ring-shaped flat surface having a constant width. Secondpressure contact surface 423 a is, for example, in an annular shape having a constant width of 1.0 mm. - As illustrated in
FIGS. 6 and 7 ,pressure contact part 423 is located between openingend 30 al offan case 30 andprotrusion 421. That is,protrusion 421 is located betweenpressure contact part 423 andtip part 422 ofcover part 420. - As described above, cover
part 420 offan case spacer 40 is in pressure contact with the outer surface offan case 30 radially outward at three parts:pressure contact part 423,protrusion 421, and tippart 422. Whenfan case spacer 40 is attached tofan case 30,cover part 420 bringspressure contact part 423,protrusion 421, and tippart 422 into pressure contact withfan case 30. - Description regarding this point is given below with reference to
FIG. 8 .FIG. 8 is a diagram illustrating howfan case spacer 40 is assembled tofan case 30 ofelectric blower 1 according to an exemplary embodiment. - As illustrated in
FIG. 8 , beforefan case spacer 40 is assembled tofan case 30,protrusion 421 offan case spacer 40 is neither curved nor deformed but extends straight towardfan case 30. - When
fan case spacer 40 is combined withfan case 30,fan case spacer 40 is pressed againstfan case 30 such that the side walls of second connectingpart 412 and fixingpart 413 offan case spacer 40 come into contact with the side surface oflid part 31 offan case 30 along the thickness oflid part 31. - At the same time, cover
part 420 offan case spacer 40 comes into pressure contact with the outer surface offan case 30 at three parts:pressure contact part 423,protrusion 421, and tippart 422. Specifically,tip part 422 andpressure contact part 423 lightly come into pressure contact with the outer surface offan case 30 to have portions in pressure contact withfan case 30 designated as firstpressure contact surface 422 a and secondpressure contact surface 423 a, respectively. - The tip of
protrusion 421 protrudes from a surface that is along the inner surface ofcover part 420. Therefore, whenfan case spacer 40 is assembled tofan case 30,protrusion 421 is pressed against the outer surface offan case 30, bent, and deformed so as to be inclined. The shape ofprotrusion 421 in cross-sectional view is substantially an acute triangle in which the radially outer surface stands straight as compared with the radially inner surface (that is, substantially an acute triangle in which the radially outer surface has a smaller inclination angle with respect to the vertical direction than the radially inner surface face). Therefore, during the process of being pressed against the outer surface offan case 30,protrusion 421 is curved to extend outward to be deformed into the shape as illustrated inFIG. 7 . - In the state described above,
fan case spacer 40 is joined tofan case 30 by ultrasonic welding. That is, fixingparts 413 made of a thermoplastic resin are, by ultrasonic vibration and welding force, melted and joined tofan case 30 made of metal. In this way,fan case spacer 40 can be joined tofan case 30. As a result,fan case spacer 40 can be assembled tofan case 30 in the state where three parts, namelypressure contact part 423,protrusion 421, and tippart 422, are in pressure contact with the outer surface offan case 30. - Operation and effects of
electric blower 1 according to the present exemplary embodiment will now be described with reference toFIG. 9 , including the background of obtainingelectric blower 1 according to the present exemplary embodiment.FIG. 9 is an enlarged cross-sectional view ofelectric blower 1X according to a comparative example. Note thatFIG. 9 corresponds toFIG. 6 . - As illustrated in
FIG. 9 ,electric blower 1X of the comparative example is similar in configuration toelectric blower 1 according to the above-described exemplary embodiment, except that the configuration of fan case spacer 40X is different. Specifically, fan case spacer 40 ofelectric blower 1 according to the above-described exemplary embodiment includesprotrusion 421 andpressure contact part 423 disposed incover part 420, whereasfan case spacer 40X ofelectric blower 1X of the comparative example has neitherprotrusion 421 norpressure contact part 423 disposed incover part 420X. - When
centrifugal fan 20 inelectric blower 1X of the comparative example illustrated inFIG. 9 is rotated, the pressure aroundoutlet 20 b ofcentrifugal fan 20 rises. Accordingly, a pressure difference is caused insidefan case 30, and the pressure aroundinlet 30 a offan case 30 becomes relatively negative. Therefore, althoughfan case spacer 40X that includesspacer part 410 and coverpart 420X is mounted onfan case 30, the difference in air pressure between the inside and outside offan case 30 may cause air to enterfan case 30 through the interface betweencover part 420X and the outer surface offan case 30, as indicated by the arrow inFIG. 9 . In other words, the airtightness betweenfan case 30 and fan case spacer 40X will be reduced. As a result, the blowing efficiency ofelectric blower 1X is reduced. In contrast, inelectric blower 1 according to the present exemplary embodiment, as illustrated inFIGS. 6 and 7 , coverpart 420 offan case spacer 40 includesprotrusion 421 that is annular, protrudes toward the outer surface offan case 30, and surroundsinlet 30 a, which corresponds to the second opening, offan case 30.Protrusion 421 is located between openingend 30 al ofinlet 30 a, which is the second opening, offan case 30 andtip part 422 ofcover part 420, and is in contact with the outer surface offan case 30. - As illustrated in
FIGS. 6 and 7 , in this configuration, the recess formed incover part 420 on a surface facingfan case 30 has space H located closer to tippart 422 thanprotrusion 421 and space L located closer toinlet 40 a thanprotrusion 421, where space H is to have a higher pressure and space L is to have a negative pressure. Accordingly, aforce causing protrusion 421 to more closely adhere tofan case 30 acts onprotrusion 421. That is,protrusion 421 serves as an adhering part (tight part) wherefan case spacer 40 andfan case 30 adhere to each other. Therefore, the airtightness betweenfan case spacer 40 andfan case 30 can be enhanced. As a result, the blowing efficiency ofelectric blower 1 can be improved. - Moreover, since
protrusion 421 is separated from fixingpart 413 for fixing fan case spacer 40 tofan case 30, stable airtightness can be obtained. - In addition, in
electric blower 1 according to the present exemplary embodiment,protrusion 421 is inclined along the outer surface offan case 30. -
- This configuration allows
protrusion 421 andfan case 30 to be in contact with each other on a wider area. Accordingly, the airtightness betweenfan case 30 andfan case spacer 40 can be further improved. Therefore, the blowing efficiency ofelectric blower 1 can be further improved. In addition, inelectric blower 1 according to the present exemplary embodiment,protrusion 421 is curved so as to extend outward frominlet 40 a, which corresponds to the third opening, offan case spacer 40.
- This configuration allows
- In this configuration,
protrusion 421 is deformed to be further tilted by a difference in air pressure between the inside and outside offan case 30. Accordingly, ascentrifugal fan 20 rotates at higher speed to cause a greater difference in air pressure between the inside and outside offan case 30,protrusion 421 andfan case 30 can be in contact with each other on a wider area. Therefore, ascentrifugal fan 20 rotates at higher speed, the airtightness betweenfan case spacer 40 andfan case 30 can be enhanced. - In addition, in
electric blower 1 according to the present exemplary embodiment,protrusion 421 is in a tapered shape. Specifically, as illustrated inFIG. 8 ,protrusion 421 before deformed in cross-sectional view is substantially in an acute triangular shape having an aspect ratio of 2 or higher. Therefore, as illustrated inFIGS. 6 and 7 ,protrusion 421 can be easily curved when pressed againstfan case 30. - Note that
protrusion 421 may be made of a resin material different from the material of parts of fan case spacer 40 other thanprotrusion 421. Specifically,protrusion 421 may be made of an elastomer having elasticity of rubber softer thancover part 420. As a result,protrusion 421 can be easily deformed when pressed against the outer surface offan case 30. For example, parts of fan case spacer 40 other thanprotrusion 421 may be made of an ABS resin, andprotrusion 421 may be made of a silicone resin or the like having rubber elasticity. In the case whereprotrusion 421 and parts other thanprotrusion 421 are made of different resin materials,protrusion 421 and parts other thanprotrusion 421 can be produced by two-color molding. - In
electric blower 1 according to the present exemplary embodiment,tip part 422 ofcover part 420 includes firstpressure contact surface 422 a that comes into close contact with the outer surface offan case 30 annularly so as to surroundinlet 30 a, which corresponds to the second opening, offan case 30. - This configuration allows two parts, namely
protrusion 421 andtip part 422, to serve as adhering parts wherefan case spacer 40 andfan case 30 adhere to each other. As a result, high and stable airtightness betweenfan case spacer 40 andfan case 30 can be easily obtained. Specifically, in the case where there is only one adhering part wherefan case spacer 40 andfan case 30 adhere to each other, the airtightness betweenfan case spacer 40 andfan case 30 is likely to vary depending on the degree of adherence (the state of pressure contact) betweenfan case spacer 40 andfan case 30, which may cause unstable airtightness betweenfan case spacer 40 andfan case 30. In contrast, the two parts, namelyprotrusion 421 andtip parts 422, serve as adhering parts wherefan case spacer 40 andfan case 30 adhere to each other. As a result, variations in the airtightness betweenfan case spacer 40 andfan case 30 can be significantly reduced, as compared with the case where there is only one adhering part. For example, by providing an adhering part ontip part 422 in addition to the adhering part ofprotrusion 421, or providing an adhering part onprotrusion 421 in addition to the adhering part ontip part 422, variations in the airtightness betweenfan case spacer 40 andfan case 30 can be significantly reduced. As a result, high and stable airtightness betweenfan case spacer 40 andfan case 30 can be easily obtained. Therefore, the blowing efficiency ofelectric blower 1 can be kept high. - Furthermore, in
electric blower 1 according to the present exemplary embodiment, coverpart 420 includespressure contact part 423 located between openingend 30 a 1 ofinlet 30 a, which is the second opening, offan case 30 andprotrusion 421.Pressure contact part 423 includes secondpressure contact surface 423 a that comes into pressure contact with the outer surface offan case 30 annularly so as to surroundinlet 30 a, which corresponds to the second opening, offan case 30. - This configuration additionally allows
pressure contact part 423 to serve as an adhering part wherefan case spacer 40 andfan case 30 adhere to each other. Therefore, high and stable airtightness betweenfan case spacer 40 andfan case 30 can be obtained more easily. In particular, as the three parts, namelyprotrusion 421,tip part 422, andpressure contact part 423, serve as adhering parts, variations in airtightness betweenfan case spacer 40 andfan case 30 can be much more significantly reduced. For example, by providingprotrusion 421 as a third adhering part in addition to a first adhering part ontip part 422 and a second adhering part onpressure contact part 423, variations in the airtightness betweenfan case spacer 40 andfan case 30 can be much more significantly reduced. As a result, high and stable airtightness betweenfan case spacer 40 andfan case 30 can be more easily obtained. Therefore, the blowing efficiency ofelectric blower 1 can be kept high more easily. - Furthermore, in
electric blower 1 according to the present exemplary embodiment,fan case spacer 40 includes fixingpart 413 for fixing fan case spacer 40 tofan case 30. - This configuration makes it easy to fix fan case spacer 40 to
fan case 30. In particular, by providing fixingpart 413 separately from the adhering parts onprotrusion 421,tip part 422, andpressure contact part 423, it is ensured that fixingpart 413 fixes fan case spacer 40 tofan case 30 and the adhering parts obtain stable airtightness betweenfan case spacer 40 andfan case 30. - In addition, in
electric blower 1 according to the present exemplary embodiment, fixingpart 413 is welded to openingend 30 al ofinlet 30 a, which is the second opening, offan case 30. - Therefore, by
melting fixing part 413, fixingpart 413 is allowed to be joined to openingend 30 al offan case 30. - For example, fixing part (welded part) 413 is welded to opening
end 30 al ofinlet 30 a, which is the second opening, offan case 30 by ultrasonic welding. In this case, fixingpart 413 is preferably made of a thermoplastic resin. - Therefore, fixing
part 413 can be melted by ultrasonic vibration and welding force and joined to openingend 30 al offan case 30. - As described above,
electric blower 1 of the present exemplary embodiment includes:rotor 11 that includes rotary shaft 13;centrifugal fan 20 that includesinlet 20 a and is attached to rotary shaft 13,inlet 20 a being a first opening;fan case 30 that includesinlet 30 a and coverscentrifugal fan 20,inlet 30 a being a second opening whose openingend 30 a 1 is located outside openingend 20 a 1 ofinlet 20 a, which is the first opening; andfan case spacer 40 that includesinlet 40 a and is attached tofan case 30,inlet 40 a being a third opening in communication withinlet 20 a, which is the first opening.Fan case spacer 40 includes: spacerpart 410 that closes off the gap between openingend 20 a 1 ofinlet 20 a, which is the first opening, and openingend 30 a 1 ofinlet 30 a, which is the second opening; and coverpart 420 that extends outward from openingend 30 a 1 ofinlet 30 a, which is the second opening, and covers the outer surface offan case 30. Coverpart 420 includes a protrusion that is annular, protrudes toward the outer surface offan case 30 and surroundsinlet 30 a, which is the second opening.Protrusion 421 is located between openingend 30 a 1 ofinlet 30 a, which is the second opening, and tippart 422 ofcover part 420, and is in contact with the outer surface offan case 30. - As a result, the airtightness between
fan case 30 andfan case spacer 40 inelectric blower 1 can be enhanced, and thus the blowing efficiency ofelectric blower 1 can be improved. - An electric blower according to the present disclosure has been described above on the basis of an exemplary embodiment; however, the present disclosure is not limited to the above exemplary embodiment.
- For example, in the above exemplary embodiment, a commutator motor with a brush is used as
motor 10 employed inelectric blower 1; however,motor 10 is not limited thereto.Motor 10 may be a brushless motor or the like. -
Electric blower 1 according to the above exemplary embodiment may be used for a vacuum cleaner, an air towel, or the like.Electric blower 1 may be applied not only to a vacuum cleaner or an air towel but also to equipment for cars, and to other household appliances or industrial equipment. - In addition, the present disclosure includes other embodiments obtained by making various modifications conceived by those skilled in the art to the above exemplary embodiment, or other embodiments achieved by any combination of the components and functions in each exemplary embodiment without departing from the spirit of the present disclosure.
- The technology of the present disclosure can be used for various electric apparatuses in which an electric blower is used. The technology of the present disclosure is particularly useful for an electric blower disposed in a vacuum cleaner or the like in which a centrifugal fan is rotated at high speed.
-
-
- 1 electric blower
- 10 motor
- 11 rotor
- 11 a rotor core
- 11 b wound coil
- 12 stator
- 13 rotary shaft
- 14 commutator
- 15 brush
- 16 first bearing part
- 17 second bearing part
- 20 centrifugal fan
- 20 a inlet (first opening)
- 20 al opening end
- 20 b outlet
- 21 first lateral plate
- 22 second lateral plate
- 23 fan blade
- 30 fan case
- 30 a inlet (second opening)
- 30 al opening end
- 31 lid part
- 32 side wall part
- 40 fan case spacer
- 40 a inlet (third opening)
- 40 al opening end
- 50 air guide
- 51 diffuser blade
- 60 motor case
- 60 a outlet
- 61 bracket
- 410 spacer part
- 411 first connecting part
- 412 second connecting part
- 413 fixing part
- 420 cover part
- 421 protrusion
- 422 tip part
- 422 a first pressure contact surface
- 423 pressure contact part
- 423 a second pressure contact surface
Claims (10)
1. An electric blower comprising:
a rotor that includes a rotary shaft;
a centrifugal fan that includes a first opening and is attached to the rotary shaft;
a fan case that includes a second opening and covers the centrifugal fan, the second opening including an opening end that is located outside an opening end of the first opening; and
a fan case spacer that includes a third opening and is attached to the fan case, the third opening being in communication with the first opening,
wherein the fan case spacer includes: a spacer part that closes off a gap between the opening end of the first opening and the opening end of the second opening; and a cover part that extends outward from the opening end of the second opening and covers an outer surface of the fan case,
the cover part includes a protrusion that is annular, protrudes toward the outer surface of the fan case, and surrounds the second opening, and
the protrusion is located between the opening end of the second opening and a tip part of the cover part and is in contact with the outer surface of the fan case.
2. The electric blower according to claim 1 , wherein the protrusion is inclined along the outer surface of the fan case.
3. The electric blower according to claim 2 , wherein the protrusion is curved to extend outward from the third opening.
4. The electric blower according to claim 2 , wherein the protrusion is in a tapered shape.
5. The electric blower according to claim 1 , wherein the tip part of the cover part includes a first pressure contact surface that adheres annularly to the outer surface of the fan case, the first pressure contact surface surrounding the second opening.
6. The electric blower according to claim 5 , wherein the cover part includes a pressure contact part located between the opening end of the second opening and the protrusion, and the pressure contact part includes a second pressure contact surface that is annularly in pressure contact with the outer surface of the fan case, the second pressure contact surface surrounding the second opening.
7. The electric blower according to claim 1 , wherein the fan case spacer includes a fixing part for fixing the fan case spacer to the fan case.
8. The electric blower according to claim 7 , wherein the fixing part is welded to the opening end of the second opening.
9. The electric blower according to claim 8 , wherein the fixing part is welded to the opening end of the second opening by ultrasonic welding.
10. The electric blower according to claim 8 , wherein the fixing part includes a thermoplastic resin.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2019014858 | 2019-01-30 | ||
JP2019-014858 | 2019-01-30 | ||
PCT/JP2019/051322 WO2020158292A1 (en) | 2019-01-30 | 2019-12-26 | Electric blower |
Publications (1)
Publication Number | Publication Date |
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US20220120287A1 true US20220120287A1 (en) | 2022-04-21 |
Family
ID=71839968
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US17/422,422 Abandoned US20220120287A1 (en) | 2019-01-30 | 2019-12-26 | Electric blower |
Country Status (5)
Country | Link |
---|---|
US (1) | US20220120287A1 (en) |
EP (1) | EP3919753A4 (en) |
JP (1) | JPWO2020158292A1 (en) |
CN (1) | CN113348306A (en) |
WO (1) | WO2020158292A1 (en) |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4947204U (en) * | 1972-07-27 | 1974-04-25 | ||
JPH0633799B2 (en) * | 1985-08-29 | 1994-05-02 | 株式会社日立製作所 | Centrifugal blower |
JP2000064993A (en) * | 1998-08-21 | 2000-03-03 | Matsushita Electric Ind Co Ltd | Motor-driven blower |
JP4402250B2 (en) * | 1999-04-30 | 2010-01-20 | 国産電機株式会社 | Blower |
JP2007321670A (en) * | 2006-06-01 | 2007-12-13 | Matsushita Electric Ind Co Ltd | Electric blower and vacuum cleaner using same |
JP4984765B2 (en) * | 2006-09-11 | 2012-07-25 | パナソニック株式会社 | Electric blower |
JP4867677B2 (en) | 2007-01-25 | 2012-02-01 | パナソニック株式会社 | Electric blower and electric vacuum cleaner using it |
JP2009041391A (en) * | 2007-08-07 | 2009-02-26 | Panasonic Corp | Electric blower and vacuum cleaner using the same |
DE102013111051A1 (en) * | 2013-10-07 | 2015-04-09 | Miele & Cie. Kg | Blower assembly for a floor care appliance |
US11092162B2 (en) * | 2016-02-24 | 2021-08-17 | Denso Corporation | Centrifugal blower |
-
2019
- 2019-12-26 EP EP19913268.9A patent/EP3919753A4/en not_active Withdrawn
- 2019-12-26 JP JP2020569460A patent/JPWO2020158292A1/ja active Pending
- 2019-12-26 US US17/422,422 patent/US20220120287A1/en not_active Abandoned
- 2019-12-26 WO PCT/JP2019/051322 patent/WO2020158292A1/en unknown
- 2019-12-26 CN CN201980090474.0A patent/CN113348306A/en active Pending
Also Published As
Publication number | Publication date |
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WO2020158292A1 (en) | 2020-08-06 |
JPWO2020158292A1 (en) | 2020-08-06 |
EP3919753A4 (en) | 2022-03-23 |
EP3919753A1 (en) | 2021-12-08 |
CN113348306A (en) | 2021-09-03 |
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