JP2019097373A - Blower and cleaner - Google Patents

Abstract

To provide a blower capable of concurrently satisfying suppression of degradation in a blowing efficiency and cooling of a circuit board.SOLUTION: The blower comprises: a motor 10 including a shaft 11 disposed along the central axis extending vertically; an impeller 20 fixed onto the shaft and rotating around the central axis; a motor housing 30 at least a portion of which is disposed outward thereof in the radial direction of the motor; a blower case 40 at least a portion of which is disposed more outward in the radial direction than an outer surface of the motor housing in the radial direction; and a circuit board 50 disposed below the motor housing and is arranged with a plurality of circuit elements. The motor housing includes a housing contraction part 321, at a lower end part, in which a radial length of the motor housing becomes shorter as it goes more downward.SELECTED DRAWING: Figure 2

Description

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

  Japanese Patent Laid-Open No. 2002-21794 includes a motor unit including a stator, a rotor, and a bracket for supporting the rotor, an impeller rotating on an output shaft of the rotor, and a fan unit including a casing covering the impeller. An electric blower is disclosed in which a circuit unit for controlling the power of the motor unit is disposed in the unit. In the electric blower, the heat-generating component of the circuit portion can be cooled efficiently.

  More specifically, in the motor unit, a housing is formed by a load side bracket made of metal which is a conductive material and a non-load side bracket. The circuit unit is composed of a first substrate and a second substrate. The first substrate and the second substrate are disposed so as to be covered by a load-side bracket and a non-load-side bracket, which are metal casings of the motor unit. The fan unit covers the impeller attached to the upper end of the rotary shaft of the rotor, an air guide which is disposed on the outer periphery of the impeller and forms a ventilation path for guiding the air flow flowing out of the impeller into the motor unit. And a casing attached to the load side bracket.

  When the electric blower rotates, the impeller rotates and a suction force is generated, and air flows into the impeller from the suction port of the casing and is discharged from the outer periphery of the impeller. The air flow discharged from the outer periphery of the impeller reaches the upper surface of the load side bracket of the motor unit, passes through the opening of the load side bracket, and is led to the first substrate and the second substrate of the circuit unit. Since a plurality of through holes penetrating the front and back of the substrate are provided in the first substrate and the second substrate, the air flow discharged from the outer periphery of the impeller reaches the upper surface of the load side bracket, and then the motor unit Flow into the interior of the

Unexamined-Japanese-Patent No. 2002-21794

  In the electric blower disclosed in Japanese Patent Application Laid-Open No. 2002-21794, since the circuit board is disposed in the axial direction of the impeller and the stator, the circuit board becomes a blowing resistance, and the blowing efficiency may be reduced. There is.

  An object of this invention is to provide the technique which can make suppression of the fall of ventilation efficiency, and cooling of a circuit board make compatible.

  An exemplary blower of the present invention comprises a motor having a shaft disposed along a central axis extending up and down, an impeller fixed to the shaft and rotating about the central axis, at least a portion of the motor A motor housing disposed radially outward, a blower case at least a portion of which is disposed radially outward of the radial outer surface of the motor housing, and a plurality of circuits disposed below the motor housing And a circuit board on which the element is disposed. The motor housing has, at its lower end portion, a housing contraction portion in which the radial length of the motor housing decreases as it goes downward.

  An exemplary vacuum cleaner of the present invention comprises the blower described above.

  According to the exemplary embodiment of the present invention, it is possible to achieve both the suppression of the decrease in the blowing efficiency of the blower and the cooling of the circuit board.

FIG. 1 is a perspective view of a blower according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a blower according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing an enlarged part of the lower side of the blower. FIG. 4 is a schematic cross-sectional view showing the relationship between the housing reduction portion and the circuit element. FIG. 5 is a perspective view of the lower housing as viewed obliquely from below. FIG. 6 is a perspective view of the lower housing as viewed obliquely from above. FIG. 7 is a plan view of the lower housing. FIG. 8 is a perspective view showing the configuration of the housing enlarged portion and the periphery thereof. FIG. 9 is a view showing the relationship between the housing through hole and the first circuit element. FIG. 10 is a view for explaining the relationship between the leg portion and the enlarged housing portion. FIG. 11 is a perspective view of a vacuum cleaner according to an embodiment of the present invention.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, in the description of the blower 100, a direction parallel to the central axis C of the blower 100 shown in FIG. 2 is “axial direction”, a direction orthogonal to the central axis C is “radial”, and the central axis C is The direction along the arc of the center is referred to as "circumferential direction". Further, in the present specification, with the axial direction as the vertical direction and the impeller 20 side up with respect to the motor 10 shown in FIG. The vertical direction is merely a name used for explanation and does not limit the actual positional relationship and direction. In the present specification, “upstream” and “downstream” indicate upstream and downstream of the flow direction of the air flow S generated when the impeller 20 is rotated, respectively.

  Further, in the present specification, in the description of the cleaner 200, the shape of each part is referred to as “downward” while the direction approaching the floor F (surface to be cleaned) in FIG. 11 is “downward” and the direction away from the floor F is “upper”. And explain the positional relationship. Note that these directions are merely names used for explanation, and do not limit the actual positional relationship and direction.

  Further, in the present specification, with respect to a plurality of elements having a width in the circumferential direction, the circumferential interval between the elements is defined as an interval between circumferentially intermediate positions of each element unless otherwise specified. However, this is a definition used for the convenience of description, and the circumferential distance between elements may be defined on another basis.

<1. Blower>
<1-1. Outline of the blower>
FIG. 1 is a perspective view of a blower 100 according to an embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of a blower 100 according to an embodiment of the present invention. As shown in FIGS. 1 and 2, the blower 100 has a motor 10, an impeller 20, a motor housing 30, a blower case 40, and a circuit board 50.

  In the blower 100, the impeller 20 and a part of the motor housing 30 are accommodated in the blower case 40. Specifically, the blower case 40 accommodates the upper side of the motor housing 30. As shown in FIG. 2, a flow passage 60 is formed between the blower case 40 and the upper housing 31 of the motor housing 30, which will be described later, in the radial direction.

  The motor 10 is housed inside a motor housing 30. The motor 10 has a shaft 11 disposed along a central axis C extending up and down. The impeller 20 is fixed to the shaft 11 and rotates around the central axis C. The motor 10 is disposed below the impeller 20 to rotate the impeller 20. The rotation of the motor 10 causes the impeller 20 to rotate around the central axis C, thereby generating an air flow.

  The motor 10 is a so-called inner rotor type motor. However, the present invention may be applied to a so-called outer rotor type motor. The motor 10 has a rotor 12 and a stator 13 in addition to the shaft 11. In the present embodiment, the shaft 11 is cylindrical. As shown in FIG. 2, the shaft 11 passes through an upper shaft hole 314 provided in an upper housing top plate portion 311 described later of the upper housing 31. The impeller 20 is fixed to an end portion protruding upward from the upper housing top plate portion 311 of the shaft 11. The shaft 11 is rotatably supported by axially spaced upper and lower bearings Br1 and Br2.

  In the present embodiment, the upper bearing Br1 and the lower bearing Br2 are ball bearings. The shaft 11 is fixed to the inner ring of the upper bearing Br1 and the lower bearing Br2. The fixing method may be, for example, bonding or press-fitting. The outer ring of the upper bearing Br1 is fixed to the upper housing 31, and the outer ring of the lower bearing Br2 is fixed to the lower housing 32 described later. The bearing that rotatably supports the shaft 11 is not limited to a ball bearing, and may be, for example, a sleeve bearing. The number of bearings is not limited to two, and may be one or three or more.

  The rotor 12 is fixed to the shaft 11. The rotor 12 rotates with the shaft 11. In the present embodiment, the rotor 12 has a cylindrical magnet 121. The magnet 121 is disposed radially outward of the shaft 11 and is fixed to the shaft 11. On the radial outer surface of the magnet 121, N poles and S poles are alternately arranged in the circumferential direction. In addition, although the magnet 121 may be comprised by one magnet, you may be comprised by the some magnet piece.

  The stator 13 is disposed radially outward of the rotor 12. The stator 13 includes a stator core 131, an insulator 132, and a coil 133. The stator core 131 is a laminate in which electromagnetic steel sheets are stacked in the axial direction. However, the stator core 131 may be, for example, a single member configured by firing and casting of powder.

  The stator core 131 has an annular shape centered on the central axis C. The annular stator core 131 has an annular core back 134 and a plurality of teeth 135. The core back 134 is annular around the central axis C. The teeth 135 project radially inward from the radially inner surface of the core back 134. The plurality of teeth 135 are arranged at equal intervals in the circumferential direction.

  The insulator 132 is an insulating member that covers at least a part of the stator core 131. The coil 133 is configured by winding a conductive wire around each tooth 135 via the insulator 132. That is, the stator 13 has a plurality of coils 133. When power is supplied from the power source to each coil 133, a magnetic flux is generated in each tooth 135. The action of the magnetic flux generated at each tooth 135 and the magnetic field generated by the magnet 121 generates a torque in the circumferential direction. As a result, the rotor 12 rotates around the central axis C together with the shaft 11.

  The motor housing 30 is at least partially disposed radially outward of the motor 10. In the present embodiment, a portion is disposed radially outward of the motor 10. The motor housing 30 is made of, for example, metal or resin. The motor housing 30 has an upper housing 31 and a lower housing 32. The lower housing 32 is disposed below the upper housing 31. The upper housing 31 and the lower housing 32 can be connected by, for example, a screw, a snap fit, or an adhesive. By dividing the motor housing 30 into two members, mass productivity of the motor housing 30 having a complicated shape can be improved. Details of the configuration of the motor housing 30 will be described later.

  The impeller 20 is a so-called diagonal flow impeller made of resin such as engineering plastic, for example. Engineering plastics are resins which are superior in mechanical properties such as strength and heat resistance to other resins. The impeller 20 may be made of another type of material such as metal. The impeller 20 has a hub portion 21 and a plurality of blades 22. The diameter of the hub portion 21 increases downward. In other words, the hub portion 21 gradually expands in diameter downward. The hub portion 21 has a lower surface recess 211 and a boss portion 212.

  The lower surface recess 211 is recessed upward from the lower surface of the hub portion 21. The lower surface recess 211 is annular with the central axis C as a center. The hub portion 21 can be reduced in weight by providing the lower surface recess 211. By reducing the weight, power consumption can be reduced and the impeller 20 can be rotated at high speed.

  The boss portion 212 is provided radially inward of the lower surface recess 211. The boss portion 212 is cylindrical with the central axis C as a center. The boss portion 212 is provided with a hole portion 213 penetrating in the axial direction centering on the central axis C. The shaft 11 is pressed into the hole 213. Thereby, the impeller 20 and the shaft 11 are connected, and the impeller 20 rotates around the central axis C. In this embodiment, it rotates in the arrow A direction of FIG. In a plan view of the blower 100, the impeller 20 rotates in the counterclockwise direction.

  The vanes 22 are provided on the outer surface of the hub portion 21. The plurality of blades 22 are spaced apart in the circumferential direction. In the present embodiment, the blades 22 are juxtaposed at predetermined intervals in the circumferential direction on the outer surface of the hub portion 21 and integrally molded with the hub portion 21. The upper portion of the blade 22 is disposed forward in the rotational direction with respect to the lower portion. That is, the blades 22 are inclined with respect to the central axis C.

  At least a part of the blower case 40 is disposed radially outward of the radial outer surface of the motor housing 30. In the present embodiment, a portion is disposed radially outward of the motor housing 30. The blower case 40 may be a separate member from the motor housing 30, or may be a single member with at least a part of the motor housing 30.

  Specifically, the blower case 40 has an upper case 41 and a lower case 42. That is, the blower case 40 is composed of two members. However, the blower case 40 may be configured by a single member.

  The upper case 41 has a cylindrical shape centered on the central axis C and tapered axially upward. The upper case 41 is disposed radially outward of the impeller 20. The upper case 41 has an intake port 43 at the top. The intake port 43 has a bell mouth 431 that bends inward from the upper end and extends downward. As a result, the diameter of the intake port 43 decreases smoothly as it goes from the upper side to the lower side. Air can be sucked smoothly by the upper case 41 having the bell mouth 431. As a result, the amount of air sucked from the intake port 43 when the impeller 20 rotates increases.

  The lower case 42 is a cylindrical shape extending in the axial direction centering on the central axis C. The lower case 42 is disposed below the upper case 41 and fixed to the upper case 41. The lower case 42 is disposed radially outward of the upper housing 31. A gap is provided between the lower case 42 and the upper housing 31 in the radial direction. In a radial gap between the lower case 42 and the upper housing 31, a plurality of stationary blades 33 described later are arranged at equal intervals in the circumferential direction. In the present embodiment, the lower case 42, the upper housing 31, and the plurality of vanes 33 are a single member.

  The circuit board 50 is disposed below the motor housing 30. The circuit board 50 is provided with a circuit for driving the motor 10, such as a power supply circuit and a control circuit. A plurality of circuit elements 51 are disposed on the circuit board 50. The plurality of circuit elements 51 are mounted on the top surface of the circuit board 50. The circuit board 50 has, for example, a printed wiring formed of a metal film, and the plurality of circuit elements 51 constitute a power supply circuit, a control circuit, and the like together with the printed wiring. In the present embodiment, the plurality of circuit elements 51 include a field effect transistor (FET) and an electrolytic capacitor.

  In addition, in this embodiment, although FET is employ | adopted as a transistor, it is not limited to this, For example, a bipolar transistor, IGBT, MOSFET etc. may be employ | adopted as a transistor. Further, in the present embodiment, an electrolytic capacitor is adopted as the capacitor, but not limited to this, for example, a ceramic capacitor, a film capacitor or the like may be adopted as the capacitor.

  As the motor 10 is driven, the shaft 11 is rotated, and the impeller 20 fixed to the shaft 11 is rotated. As indicated by thick arrows in FIG. 2, the air flow S is generated as the impeller 20 rotates. The air flow S generated by the rotation of the impeller 20 flows into the flow path 60 formed between the upper housing 31 and the lower case 42 in the radial direction. The air flow S flowing into the flow passage 60 is rectified by a stator blade 33 described later. The air flow S becomes a flow close to axial symmetry about the central axis C by the stationary blades 33. Then, the air flow S blows downward from the lower end of the blower case 40. A part of the air flow S blown downward flows to the outside of the blower 100. Further, another part of the air flow S blown downward flows toward the circuit board 50.

<1-2. Motor Housing Details>
As described above, in the present embodiment, the motor housing 30 is configured by the upper housing 31 and the lower housing 32. That is, the motor housing 30 is composed of two members. However, the motor housing 30 may be configured by a single member.

<1-2-1. Upper housing>
As shown in FIG. 2, the upper housing 31 has an upper housing top plate portion 311 and an upper housing cylindrical portion 312. The upper housing top plate portion 311 extends in the direction orthogonal to the central axis C. The upper housing top plate portion 311 has a circular shape centering on the central axis C in plan view from the axial direction. The upper housing cylindrical portion 312 extends axially downward from the radial outer edge of the upper housing top plate portion 311. The upper housing cylindrical portion 312 has a cylindrical shape centered on the central axis C. The upper housing top plate portion 311 and the upper housing cylindrical portion 312 are single members. The upper housing cylindrical portion 312 is disposed radially outward of the stator 13.

  The lower surface of the upper housing top plate portion 311 axially faces the rotor 12 and the stator 13. The upper housing top plate portion 311 has an upper bearing holding portion 313 and an upper shaft hole 314. The upper bearing holding portion 313 has a recess that is recessed upward at the center of the lower surface of the upper housing top plate portion 311. Further, the upper axial hole 314 is a through hole that passes through the central axis C in the axial direction. The centers of the upper bearing holder 313 and the upper shaft hole 314 coincide with each other. The outer ring of the upper bearing Br1 is fixed to the upper bearing holding portion 313. The shaft 11 passes through the upper shaft hole 314.

  The stator 13 is press-fitted into the inner peripheral surface of the upper housing cylindrical portion 312. A plurality of vanes 33 are provided on the outer peripheral surface of the upper housing cylindrical portion 312. The plurality of vanes 33 are disposed radially outward of the radially outer surface of the upper housing cylindrical portion 312 and radially inward of the radially inner surface of the lower case 42.

  In the present embodiment, the upper housing cylindrical portion 312 and the vane 33 are a single member. However, the upper housing cylindrical portion 312 and the vane 33 may be separate members. In this case, the stator vanes 33 may be fixed to the upper housing cylindrical portion 312 by, for example, bonding. Further, in the present embodiment, the vane 33 is a single member as well as the lower case 42. That is, the upper housing 31, the vanes 33, and the lower case 42 are single members.

  The plurality of vanes 33 are arranged at equal intervals in the circumferential direction on the radial outer surface of the upper housing 31. Each stationary blade 33 is formed in a plate shape, and inclines in the direction opposite to the rotation direction of the impeller 20 as it goes upward. The vanes 33 are convexly curved on the impeller 20 side. The radially outer surfaces of the plurality of vanes 33 are in contact with the radially inner surface of the lower case 42. The plurality of stationary blades 33 are arranged in parallel in the circumferential direction, and guide the air flow S downward when the blower 100 is driven. The vanes 33 are disposed inside the flow passage 60 and rectify the air flow S flowing in the flow passage 60.

  Further, the vanes 33 are arranged at equal intervals in the circumferential direction on the radial outer surface of the upper housing 31. As a result, the air flow S on the radial outer surface of the upper housing 31 can be made axially symmetrical, and the cooling characteristics of the upper housing 31 can be made uniform in the circumferential direction.

  In the motor 10, heat is generated from the coil 133 and its surroundings as the motor 10 rotates. The heat is transmitted to the upper housing 31. A stator blade 33 protruding radially outward is provided on the outer peripheral surface of the upper housing 31, and the stator blade 33 is disposed in the flow passage 60. Therefore, the vanes 33 not only rectify the air flow S, but also play a role as a radiation fin for dissipating the heat of the upper housing 31 to the outside. Thus, the upper housing 31 heated by the heat of the stator 13 can be efficiently cooled.

<1-2-2. Lower housing>
FIG. 3 is a schematic cross-sectional view showing a part of the lower side of the blower 100 in an enlarged manner. As shown in FIG. 1 to FIG. 3, the motor housing 30 has a housing contraction portion 321 at the lower end, in which the radial length of the motor housing 30 decreases as it goes downward. In the present embodiment, the lower housing 32 has a housing contraction portion 321. The housing contraction portion 321 has a specific shape provided on the radial outer surface of the lower housing 32.

  As shown in FIG. 3, the housing reduction portion 321 guides a portion of the air flow S blown out from the lower end of the blower case 40 through the flow passage 60 with the rotation of the impeller 20 downward and radially inward. Can. The air flow S induced by the housing reduction portion 321 can be directed to the circuit board 50 disposed below the motor housing 30 to cool the heat-generating component on the circuit board 50. In other words, the air flow S induced by the housing reduction portion 321 is smoothly guided toward the circuit board 50 inside the blower case 40 and is led to the outside of the blower case 40. For this reason, in the air blower 100, suppression of the fall of ventilation efficiency and cooling of the circuit board 50 can be made to make compatible.

  The other part of the air flow S blown out from the lower end of the blower case 40 flows to the outside of the air blower 100 without hitting the circuit board 50. At the lower end portion of the radial inner surface of the blower case 40, there is provided a blower case enlarged portion 421 which enlarges the inner diameter as it goes downward. In the present embodiment, the blower case enlarged portion 421 is provided in the lower case 42. By providing the blower case enlarged portion 421, the air flow S not directed to the circuit board 50 can be generated efficiently. By generating the air flow S not directed to the circuit board 50, it is possible to suppress that the air pressure under the impeller 20 becomes too high. That is, it is possible to suppress the decrease in the blowing efficiency by suppressing the load applied to the impeller 20 from becoming too large.

  In the present embodiment, the housing reduction portion 321 is a curved portion that is convex downward and radially outward. That is, the housing contraction portion 321 is a convex curved surface. With this configuration, the air flow S from the impeller 20 can be smoothly guided toward the circuit board 50. That is, the air flow S from the impeller 20 can be efficiently directed toward the circuit board, and the cooling efficiency can be improved.

  The housing reduction portion 321 may have another shape such as, for example, an inclined surface which is directed radially inward as it goes downward, or a curved surface which is recessed upward and in the radial direction.

  FIG. 4 is a schematic cross-sectional view showing the relationship between the housing reduction portion 321 and the circuit element 51. As shown in FIG. As shown in FIG. 4, the first circuit element 511 which becomes the highest temperature among the plurality of circuit elements 51 is positioned radially inward of the radially outer end of the housing reduced portion 321. In the present embodiment, the first circuit element 511 is a FET. The first circuit element 511 may be other than an FET. In addition, "it becomes the highest temperature" is the expression which compared the temperature in case the air flow S is not applied. According to the configuration of the present embodiment, the air flow S can be easily applied to the first circuit element 511 which becomes the highest temperature, and the first circuit element 511 and the circuit board 50 can be efficiently suppressed from becoming high temperature. .

  Preferably, the entire first circuit element 511 is positioned radially inward of the housing contraction portion 321. However, the first circuit element 511 may have a configuration in which a portion thereof is positioned radially inward of the housing reduction portion 321. When there are a plurality of first circuit elements 511, it is preferable that all the first circuit elements 511 be positioned radially inward of the radially outer end of the housing reduced portion 321. However, the plurality of first circuit elements 511 may include the first circuit element 511 located radially outward of the radially outer end of the housing reduced portion 321.

  Preferably, at least a part of the circumferential area of the housing reduction portion 321 radially overlaps the first circuit element 511. Thus, the air flow S induced by the housing reduction portion 321 can be applied directly to the first circuit element 511 which is the highest temperature, and the first circuit element 511 and the circuit board 50 can be efficiently cooled. .

  When there are a plurality of first circuit elements 511, it is preferable that all the first circuit elements 511 radially overlap at least a part of the circumferential area of the housing contraction portion 321. However, the plurality of first circuit elements 511 may include the first circuit elements 511 that do not overlap in the radial direction with the circumferential area of the housing reduced portion 321.

  As shown in FIG. 4, the motor housing 30 has a housing recess 322 which is recessed upward in the radial direction of the housing reduction portion 321. In the present embodiment, the lower housing 32 has a housing recess 322. The housing recess 322 is circular around the central axis C.

  As shown in FIG. 4, at least the upper portion of the second circuit element 512 having the longest axial length among the plurality of circuit elements 51 is accommodated in the housing recess 322. In the present embodiment, the second circuit element 512 is an electrolytic capacitor. The second circuit element 512 may be other than an electrolytic capacitor. The upper part of the second circuit element 512 is accommodated in the housing recess 322, and the lower part is located outside the housing recess 322.

  According to the configuration of the present embodiment, since the upper portion of the second circuit element 512 having the longest axial length is contained in the housing recess 322, the axial distance between the motor housing 30 and the circuit board 50 can be reduced. It can be made smaller. That is, the axial size of the blower 100 can be reduced. Further, there is no need to arrange the second circuit element 512 radially outward of the radially outer end of the motor housing 30 in order to reduce the axial size of the blower 100, and the size of the blower 100 in the radial direction Can also be smaller.

  When there are a plurality of second circuit elements 512, it is preferable that at least the upper part of all the second circuit elements 512 be accommodated in the housing recess 322. However, among the plurality of second circuit elements 512, the second circuit element 512 in which at least the upper part is not accommodated in the housing recess 322 may be included.

  FIG. 5 is a perspective view of the lower housing 32 as viewed obliquely from below. FIG. 6 is a perspective view of the lower housing 32 as viewed obliquely from above. FIG. 7 is a plan view of the lower housing 32. FIG.

  As shown in FIGS. 5 to 7, the lower housing 32 has a lower housing cylindrical portion 323 and a lower housing lid 324. The lower housing cylindrical portion 323 has a cylindrical shape extending in the axial direction centering on the central axis C. The lower housing cylindrical portion 323 has the housing contraction portion 321 on the outer surface in the radial direction, so the radial length becomes shorter as it goes downward. The lower housing lid portion 324 has a plate shape orthogonal to the central axis C. The lower housing lid 324 is disposed in the lower housing cylinder 323. The lower housing cylindrical portion 323 and the lower housing lid portion 324 are a single member. The lower housing lid 324 constitutes an upper wall of the housing recess 322 which is recessed upward.

  The lower housing lid portion 324 has a lower bearing holding portion 324a and a lower shaft hole 324b. The lower bearing holding portion 324 a has a recessed portion that protrudes upward from the central portion of the lower housing lid portion 324 and in which the central portion is recessed downward. The outer ring of the lower bearing Br2 is fixed to the recess of the lower bearing holding portion 324a. The lower axial hole 324 b is a through hole which axially penetrates the central portion of the lower housing lid 324. The shaft 11 passes through the lower shaft hole 324b. The lower bearing holding portion 324a and the lower shaft hole 324b have their centers aligned.

  The lower housing 32 is attached to the lower side of the upper housing 31. That is, the upper end portion of the lower housing cylindrical portion 323 contacts the lower end portion of the upper housing cylindrical portion 312. Thereby, at least a part of the lower surface of the upper housing 31 is covered by the lower housing 32. In the present embodiment, the lower housing 32 is fixed to the upper housing 31 using a screw. The upper housing 31 and the lower housing 32 may be made of the same material or different materials.

  As shown in FIG. 5, the lower housing 32 has a housing opening 325. In other words, motor housing 30 has a housing opening 325. The housing opening 325 penetrates between the housing contraction portion 321 and the housing recess 322 in the radial direction. In the present embodiment, the housing opening 325 is a notch that is recessed upward from the bottom surface of the lower housing 32. The notch is rectangular in plan view from the radial direction. However, the notch is not limited to a rectangular shape, and may have another shape such as a semicircular shape. Also, the housing opening 325 may be a through hole instead of a notch. The air flow S can escape from the housing opening 325 to reduce the amount of air flow stagnating in the housing recess 322. Thereby, the load applied to the impeller 20 can be reduced. Further, since the air flow can be suppressed from staying in the housing concave portion 322, for example, the circuit element 51 such as an electrolytic capacitor can be cooled efficiently.

  In the present embodiment, a plurality of housing openings 325 are provided in the circumferential direction. The plurality of housing openings 325 are arranged at equal intervals in the circumferential direction. In particular, lower housing 32 has three housing openings 325. The three housing openings 325 are provided at intervals of 120 ° in the circumferential direction. According to this, in the circumferential direction, the air flow S can be uniformly dissipated to the outside through the housing opening 325.

  As shown in FIGS. 5 and 6, the lower housing 32 has a housing groove 326 which is recessed radially inward in the housing contraction portion 321. In other words, the motor housing 30 has a housing groove 326 which is recessed radially inward in the housing contraction portion 321. The housing groove 326 is recessed radially inward from the curved surface that constitutes the housing contraction portion 321. In the present embodiment, the housing groove 326 extends from the upper end to the lower end of the housing contraction portion 321.

  The housing groove 326 is provided at a position overlapping the housing opening 325 in the radial direction. Specifically, in plan view from the radial direction, the housing groove 326 is larger than the housing opening 325, and the housing opening 325 is provided in the area of the housing groove 326. In the present embodiment, the number of housing grooves 326 is three, which is the same as the number of housing openings 325. The three housing grooves 326 are equally spaced in the circumferential direction.

  At the position where the housing groove 326 is provided, the air flow S along the housing contraction portion 321 does not occur, and it is difficult for most of the air flow S to have a component directed inward in the radial direction. For this reason, at the position where the housing groove 326 is provided, it becomes difficult for the air flow S to go to the circuit board 50. That is, by providing the housing groove 326, it is possible to suppress that the amount of air flow flowing toward the circuit board 50 becomes too large. That is, it is possible to suppress an increase in the amount of air flow rising against the circuit board 50 and to suppress an increase in air pressure in a space between the upper surface of the circuit board 50 and the lower end of the motor housing 30 in the axial direction. The load applied to the impeller 20 can be reduced.

  As shown in FIGS. 5 to 7, the lower housing 32 has a housing enlargement 327. In other words, the motor housing 30 has a housing enlargement 327. The housing enlarged portion 327 is disposed between the circumferential direction of the housing reduced portion 321 adjacent in the circumferential direction, and protrudes outward in the radial direction. The housing enlarged portion 327 protrudes radially outward from the radial outer surface of the lower housing cylindrical portion 323. The housing enlarged portion 327 is a single member with the lower housing cylindrical portion 323. However, the housing enlarged portion 327 may be a separate member from the lower housing cylindrical portion 323.

  As shown in FIGS. 6 and 7, the housing enlarged portion 327 has an enlarged outer wall portion 327 a and a pair of enlarged portion side walls 327 b. The enlarged outer wall portion 327 a is disposed radially outward of the housing reduced portion 321. The pair of enlarged portion side wall portions 327 b connects both circumferential end portions of the enlarged portion outer wall portion 327 a and the housing reduced portion 321. The housing enlarged portion 327 is substantially U-shaped in plan view from the axial direction. The housing enlarged portion 327 extends from the upper end to the lower end of the lower housing cylindrical portion 323 in the axial direction.

  In the position where the housing enlarged portion 327 is provided, the lower housing 32 has a radial length larger than the position where the housing enlarged portion 327 is not provided. In the present embodiment, a plurality of housing enlargements 327 are arranged at equal intervals in the circumferential direction. Specifically, the number of housing enlargements 327 is three. However, the number of housing enlargements 327 may be other than three, and may be singular. The housing groove 326 and the housing opening 325 are provided one by one between two circumferentially adjacent housing enlargements 327.

  An axially penetrating housing through hole 328 is provided radially inward of the radially outer surface of the housing enlarged portion 327. Specifically, the housing through hole 328 includes a space surrounded by the enlarged outer wall 327a and the pair of enlarged side walls 327b. The housing through hole 328 also includes a space axially penetrating a portion of the lower housing lid 324.

  In the present embodiment, a plurality of housing enlargements 327 are arranged at equal intervals at predetermined angles in the circumferential direction. For this purpose, a plurality of housing through holes 328 are arranged in the circumferential direction. In detail, three housing through holes 328 are arranged at equal intervals every 120 ° in the circumferential direction. In a plan view from the axial direction, at least a part of the housing through hole 328 overlaps with the flow passage 60 formed between the upper housing 31 and the lower case 42. For this reason, part of the air flow S blown downward from the flow passage 60 can pass through the housing through hole 328.

  As shown in FIGS. 6 and 7, among the pair of enlarged side wall portions 327b, the enlarged side wall portion 327bR disposed on the rear side in the rotational direction of the impeller has a through hole enlarged portion 327c. Arrows A in FIGS. 6 and 7 indicate the rotation direction of the impeller 20. The through hole enlarged portion 327 c is provided on the surface on the front side in the rotational direction of the impeller 20. The through hole enlarged portion 327 c is directed rearward in the rotational direction of the impeller 20 as it extends upward. In other words, by providing the through hole enlarged portion 327c, the upper end of the housing through hole 328 is wider than the lower end. According to this configuration, the air flow S having the rotation direction component of the impeller 20 can be smoothly guided downward along the through hole enlarged portion 327 c.

  FIG. 8 is a perspective view showing the configuration of the housing enlarged portion 327 and the periphery thereof. As shown in FIG. 8, the connection portion 52 is disposed in the housing through hole 328. The connection portion 52 electrically connects the motor 10 and the circuit board 50. The connection portion 52 has conductivity, and electrically connects the coil 133 and the circuit board 50. The connection unit 52 may be, for example, a tab terminal. In the present embodiment, the number of connection portions 52 is three, and one connection portion 52 is disposed in each housing through hole 328.

  According to this embodiment, since the connection portion 52 can be disposed outward in the radial direction of the circuit board 50, many circuit elements 51 can be disposed inward in the radial direction of the housing contraction portion 321. Further, the connection portion 52 can be cooled by the air flow S passing through the housing through hole 328. Further, in the present embodiment, since the plurality of housing through holes 328 are provided in the circumferential direction, each of the plurality of connecting portions 52 can be disposed in the housing through hole 328, and the respective connecting portions 52 are efficiently cooled. be able to.

  As shown in FIG. 7, the housing through hole 328 extends forward in the rotational direction of the impeller 20 as it extends radially inward. In the present embodiment, the shapes of the three housing through holes 328 are the same. That is, when one housing through hole 328 is rotated by 120 ° around the central axis C, it overlaps with another adjacent housing through hole 328. By configuring in this manner, it is possible to efficiently guide the air flow having the forward component in the rotational direction of the impeller 20.

  FIG. 9 is a view showing the relationship between the housing through hole 328 and the first circuit element 511. As shown in FIG. FIG. 9 is a view assuming that the lower housing 32 is viewed from above. In FIG. 9, the first circuit element 511 overlaps the lower housing 32 in the axial direction and can not be seen originally. However, in FIG. 9, the first circuit element 511 is indicated by an alternate long and short dash line. In FIG. 9, the arrow A indicates the rotation direction of the impeller 20.

  As described above, the first circuit element 511 is a circuit element that becomes the highest temperature among the plurality of circuit elements 51. As shown in FIG. 9, it is preferable that at least one of the first circuit elements 511 be located on the rear side in the rotational direction of the impeller 20 than the circumferential intermediate position IP. The circumferential intermediate position IP is the rotational direction front end of the impeller in the housing through hole 328R disposed on the rear side in the rotational direction of the impeller 20 and the rotation of the impeller 20 between the circumferential directions of the housing through holes 328 adjacent in the circumferential direction. It is an intermediate position with respect to the rotational direction rear end of the impeller 20 in the housing through hole 328F disposed on the front side in the direction.

  With this configuration, the air flow S having the rotational direction component of the impeller 20 can be applied directly to the first circuit element 511, and the first circuit element 511 can be cooled efficiently. That is, the high temperature of the first circuit element 511 and the circuit board 50 can be efficiently suppressed. In addition, it is preferable that the whole 1st circuit element 511 is located in the rotation direction back side of the impeller 20 rather than circumferential direction intermediate position IP. However, the first circuit element 511 may be configured such that a portion of the first circuit element 511 is located rearward of the circumferential intermediate position IP in the rotational direction of the impeller 20.

  As shown in FIGS. 1, 5 and 6, the lower housing 32 has a plurality of legs 329. That is, motor housing 30 has a plurality of legs 329. The plurality of legs 329 project downward and are connected to the circuit board 50. In the present embodiment, the leg 329 protrudes downward from the lower end of the lower housing cylindrical portion 323. The leg portion 329 is in the form of a cylindrical tube that extends in the axial direction. A screw is passed through the leg 329 to connect the motor housing 30 and the circuit board 50. In the present embodiment, the number of legs 329 is three. The plurality of legs 329 are arranged at equal intervals at predetermined angles in the circumferential direction. The three legs 329 are arranged at equal intervals every 120 ° in the circumferential direction.

  FIG. 10 is a view for explaining the relationship between the leg 329 and the housing enlarged portion 327. As shown in FIG. FIG. 10 is a plan view of the lower housing 32 as viewed from below. In FIG. 10, arrow A indicates the rotation direction of the impeller 20.

  The three housing enlargements 327 and the three legs 329 are all arranged at equal intervals in the circumferential direction at predetermined angles α (= 120 °). However, circumferential positions of the housing enlarged portion 327 and the leg portion 329 are different. In other words, the circumferential positions of the housing enlarged portion 327 and the leg portion 329 are shifted.

Each housing enlarged portion 327 is disposed on the rear side in the rotational direction of the impeller 20 at an angle β smaller than a half of the predetermined angle α with reference to any one of the plurality of legs 329. That is, the following relational expression (1) holds for α and β. In the present embodiment, β is smaller than 60 ° because α = 120 °. Each housing enlargement 327 is preferably arranged as close as possible to the rear side of the impeller 20 with respect to each leg 329. With such a configuration, the air flow S generated by the rotation of the impeller 20 can be prevented from being disturbed by the leg portion 329, and the air volume of the blower 100 can be improved.
β <α / 2 (1)

  A housing opening 325 and a housing groove 326 are disposed on the rear side in the rotational direction of the impeller 20 with respect to the housing enlarged portion 327 between the circumferential direction of the two leg portions 329 adjacent in the circumferential direction.

<2. Vacuum cleaner>
Next, an embodiment of the cleaner 200 to which the air blower 100 of the present embodiment is applied will be described. FIG. 11 is a perspective view of a vacuum cleaner 200 according to an embodiment of the present invention. As shown in FIG. 11, the vacuum cleaner 200 has a blower 100. The vacuum cleaner 200 is a so-called stick-type vacuum cleaner. The vacuum cleaner having the blower 100 may be another type of vacuum cleaner such as a so-called robot type, a canister type, or a handy type.

  The vacuum cleaner 200 has a housing 201 provided with an intake part 202 and an exhaust part 203 on the lower surface and the upper surface, respectively. The vacuum cleaner 200 has a rechargeable battery (not shown) and is operated by the power supplied from the battery. However, the vacuum cleaner 200 may be operated by power supplied via a power cord having a power cord and connected to a power outlet provided on a wall of a living room.

  In the housing 201, an air passage (not shown) connecting the intake portion 202 and the exhaust portion 203 is formed. In the air passage, a dust collection unit (not shown), a filter (not shown), and a blower 100 are arranged in order from the intake unit 202 (upstream) to the exhaust unit 203 (downstream). Dust such as dust contained in the air flowing in the air passage is collected by a filter and collected in a dust collection unit formed in a container shape. The dust collection unit and the filter are detachably provided to the housing 201.

  A grip portion 204 and an operation portion 205 are provided on the top of the housing 201. The user can move the cleaner 200 by holding the grip 204. The operation unit 205 has a plurality of buttons 205a. The user sets the operation of the cleaner 200 by operating the button 205a. For example, by the operation of the button 205a, the drive start, the drive stop, and the change of the number of rotations of the blower 100 are instructed. A rod-like suction pipe 206 is connected to the intake unit 202. A suction nozzle 207 is detachably attached to the suction pipe 206 at the upstream end of the suction pipe 206. The upstream end of the suction pipe 206 is the lower end of the suction pipe 206 in FIG.

  According to the vacuum cleaner 200 of the present embodiment, it is possible to cool the circuit board 50 of the air blower 100 while suppressing a decrease in air blowing efficiency. For this reason, the operation of the circuit of the blower 100 can be stabilized, and hence the operation of the cleaner 200 can be stabilized.

<3. Points to keep in mind>
Various technical features disclosed in the present specification can be variously modified without departing from the spirit of the technical creation. In addition, the plurality of embodiments and modifications shown in the present specification may be implemented in combination as far as possible.

  The present invention can be used, for example, in an electric device having a blower such as a vacuum cleaner.

DESCRIPTION OF SYMBOLS 1 ... air blower 10 ... motor 11 ... shaft 20 ... impeller 30 ... motor housing 31 ... upper housing 32 ... lower housing 40 ... blower case 50 ... circuit Substrate 51 ··· Circuit element 52 ··· Connection portion 100 ··· Blower 200 ··· Vacuum cleaner 321 ··· Housing contraction portion 322 ··· Housing recess 325 ··· Housing opening 326 ··· Housing Groove 327: housing enlarged portion 327a: enlarged portion outer wall portion 327b: enlarged portion side wall portion 327c: through hole enlarged portion 328: housing through hole 329: leg portion 511: fifth 1 circuit element 512: second circuit element C: central axis

Claims (16)

A motor having a shaft disposed along a central axis extending up and down;
An impeller fixed to the shaft and rotating about the central axis;
A motor housing at least a part of which is disposed radially outward of the motor;
A blower case at least a part of which is disposed radially outward of the radial outer surface of the motor housing;
A circuit board disposed below the motor housing and on which a plurality of circuit elements are disposed;
Have
The motor housing has a housing contraction portion at a lower end portion, in which a radial length of the motor housing becomes shorter as it goes downward.   The air blower according to claim 1, wherein the housing contraction portion is a curved portion that is convex downward and radially outward.   The air blower according to claim 1 or 2, wherein the first circuit element which becomes the highest temperature among the plurality of circuit elements is positioned radially inward of the radially outer end of the housing contraction portion.   The air blower according to claim 3, wherein a circumferential region of at least a part of the housing contraction portion radially overlaps the first circuit element. The motor housing has a housing recess that is recessed upward in the radial direction of the housing reduction portion,
The air blower according to any one of claims 1 to 4, wherein at least a top portion of a second circuit element having the longest axial length among the plurality of circuit elements is accommodated in the housing recess. The motor housing is
A housing recess which is recessed upward in the radial direction of the housing reduced portion;
A housing opening passing through a radial direction between the housing contraction portion and the housing recess;
The air blower of any one of Claim 1 to 4 which has these. A plurality of the housing openings are provided in the circumferential direction,
The air blower according to claim 6, wherein the plurality of housing openings are equally spaced in the circumferential direction.   The air blower according to any one of claims 1 to 7, wherein the motor housing has a housing groove which is recessed radially inward in the housing contraction portion. The motor housing is
Upper housing,
A lower housing disposed below the upper housing;
Have
The air blower according to any one of claims 1 to 8, wherein the lower housing has the housing contraction portion. The motor housing is disposed between the circumferential direction of the housing reduced portions adjacent in the circumferential direction, and has a housing enlarged portion projecting radially outward,
An axially penetrating housing through hole is provided radially inward of the radially outer surface of the housing enlarged portion,
The air blower according to any one of claims 1 to 9, wherein a connection portion electrically connecting the motor and the circuit board is disposed in the housing through hole.   The air blower according to claim 10, wherein the housing through hole extends to the rotational direction front side of the impeller as it goes radially inward.   At least one of the plurality of first circuit elements that becomes the highest temperature among the plurality of circuit elements is the housing penetration that is disposed on the rear side in the rotational direction of the impeller between circumferential directions of the housing penetration holes adjacent in the circumferential direction. More to the rear in the rotational direction of the impeller than at a circumferentially intermediate position of the rotational direction front end of the impeller in the hole and the rotational rear end of the impeller in the housing through hole disposed on the front side of the impeller in the rotational direction. The air blower according to claim 11, which is arranged.   The air blower according to any one of claims 10 to 12, wherein a plurality of the housing through holes are arranged in the circumferential direction. The housing enlargement is
An enlarged outer wall portion disposed radially outward of the housing reduced portion;
A pair of enlarged side wall portions connecting the circumferential end portions of the enlarged outer wall portion to the housing reduced portion;
Have
Of the pair of enlarged portion side wall portions, the enlarged portion side wall portion disposed on the rear side in the rotational direction of the impeller is directed to the upper side in the rotational direction front side of the impeller. The air blower according to any one of claims 10 to 13, further comprising a through hole enlarged portion directed to. A plurality of the housing enlargements are arranged at equal intervals in the circumferential direction at regular intervals,
The motor housing has a plurality of legs projecting downward and connected to the circuit board,
The plurality of legs are arranged at equal intervals in the circumferential direction at predetermined intervals.
The respective housing enlargements are disposed on the rear side in the rotational direction of the impeller with an angle offset smaller than a half of the predetermined angle with reference to any one of the plurality of legs. The blower according to any one of 14.   A vacuum cleaner comprising the blower according to any one of claims 1 to 15.

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