JP2018105268A - Blowing device and cleaner equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blowing device capable of improving ventilation efficiency, and a cleaner equipped with the blowing device.SOLUTION: A blowing device is equipped with a fan casing 2 which stores an impeller 10 and a motor housing 21 storing a motor, and configures a channel between the motor housing and the fan casing. An upper part of the fan casing covers an upper part of the impeller and is equipped with an intake port 3 opening in a vertical direction. On a lower part of the fan casing, an exhaust port 4 communicating with the intake port through the channel is provided. The impeller has a base portion 11 expanding its diameter downward, and a plurality of blades 12 arranged in parallel in a circumferential direction on an outer peripheral surface of the base portion. On a lower surface of the base portion, an annular impeller projecting portion 11p is provided, and on an upper surface of the motor housing, an annular groove portion 21g depressed downward is provided. The groove portion stores at least a part of the projecting portion.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a blower and a vacuum cleaner provided with the blower.

  A conventional electric blower (blower) is disclosed in Patent Document 1. This electric blower is mounted on a vacuum cleaner and includes an impeller that rotates around a central axis that extends vertically, and an electric motor that is disposed above the impeller. The impeller has a plurality of blades formed of a curved surface, and is housed in a fan case that opens an intake port upward. The electric motor has a cylindrical bracket, and a rotor and a stator are accommodated in the bracket. The rotor is connected to the rotation shaft of the impeller. A communication port is provided on the outer peripheral portion of the upper surface of the bracket. An exhaust port is provided on the lower surface of the bracket.

  An air guide having an air passage that connects the lower end of the impeller and the communication port of the bracket is provided below the fan case. A space is provided between the upper surface of the bracket and the impeller in the vicinity of the connection portion between the rotor and the rotation shaft of the impeller.

  In the electric blower configured as described above, when the rotor rotates, air flows into the fan case through the air inlet. The air that has flowed into the fan case flows between adjacent blades, and accelerates radially outward along the blades. The air accelerated toward the outer side in the radial direction is blown downward on the outer side in the radial direction of the impeller and flows through the air passage. The airflow flowing through the air passage flows into the bracket via the communication port, and is exhausted from the exhaust port to the outside of the electric motor.

JP 2005-307985 A

  However, according to the blower described in the above patent document, a part of the air current enters the space when the impeller rotates. For this reason, there existed a problem that the ventilation efficiency of an air blower was bad.

  An object of this invention is to provide the air blower which can improve ventilation efficiency, and a cleaner provided with the same.

  An exemplary blower of the present invention is a blower, an impeller that rotates around a central axis that extends vertically, a motor that is disposed below the impeller and that rotates the impeller, and a motor that houses the motor And a fan casing that houses the impeller and the motor housing and forms a flow path in the gap between the motor housing, and an upper portion of the fan casing covers the top of the impeller and is vertically An exhaust port that opens to the bottom of the fan casing, and an exhaust port that communicates with the intake port via the flow path is provided in the lower portion of the fan casing. A plurality of blades juxtaposed in the circumferential direction on the outer peripheral surface of the base portion, and an annular impeller convex portion is provided on the lower surface of the base portion. The upper surface of the motor housing is provided with an annular groove recessed in the lower, it said the groove at least a portion of the convex portion is housed.

  According to the exemplary present invention, it is possible to provide an air blower capable of improving the air blowing efficiency and a vacuum cleaner including the air blower.

FIG. 1 is a perspective view of a vacuum cleaner provided with a blower according to an embodiment of the present invention. FIG. 2 is a perspective view of the air blower according to the embodiment of the present invention. FIG. 3 is a front view of the inside of the air blower according to the embodiment of the present invention. FIG. 4 is a side cross-sectional view of the air blower according to the embodiment of the present invention. FIG. 5 is a perspective view of the blower according to the embodiment of the present invention cut from a horizontal section passing above the inlet and viewed from above. FIG. 6 is a cross-sectional plan view of the air blower according to the embodiment of the present invention. FIG. 7 is a perspective view of the impeller of the air blower according to the embodiment of the present invention. FIG. 8 is a plan view of the impeller of the air blower according to the embodiment of the present invention. FIG. 9 is a plan cross-sectional view passing through the lower end portion of the impeller of the blower according to the embodiment of the present invention. FIG. 10 is a cross-sectional view taken along a cross section perpendicular to the outer peripheral surface of the base portion along the circumferential direction of the upper end portion of the impeller of the blower according to the embodiment of the present invention. FIG. 11 is a cross-sectional view taken along a cross section perpendicular to the outer peripheral surface of the base portion along the circumferential direction of the lower end portion of the impeller of the blower according to the embodiment of the present invention. FIG. 12 is a side cross-sectional view for explaining the relationship between the blades and the stationary blades of the blower according to the embodiment of the present invention. FIG. 13 is an enlarged cross-sectional view of a cross section (a cross section including the central axis) along the radial direction of the peripheral portion of the motor housing and the impeller of the blower according to the embodiment of the present invention. FIG. 14 is an enlarged plan cross-sectional view in which a stationary blade of a blower according to a first modification of the embodiment of the present invention is enlarged. FIG. 15 is an enlarged cross-sectional view of a cross section (a cross section including a central axis) along a radial direction of a peripheral portion of a motor housing and an impeller of a blower device according to a second modification of the embodiment of the present invention. FIG. 16 is an enlarged side cross-sectional view of the upper peripheral portion of the motor housing of the blower according to the second modification of the embodiment of the present invention. FIG. 17 is an enlarged plan cross-sectional view of the vicinity of the inlet of the blower according to the third modification of the embodiment of the present invention.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this specification, in the blower device 1, the direction parallel to the central axis C of the blower device 1 is “axial direction”, the direction orthogonal to the central axis C of the blower device 1 is “radial direction”, and The direction along the arc centered on the central axis C is referred to as “circumferential direction”. Similarly, for the impeller 10, the directions that coincide with the axial direction, the radial direction, and the circumferential direction of the blower device 1 in the state of being incorporated in the blower device 1 are simply “axial direction”, “radial direction”, and “circumferential direction”, respectively. Called “direction”. Further, in the present specification, in the blower device 1, the shape and the positional relationship of each part will be described with the axial direction being the vertical direction and the air inlet 3 side of the fan casing 2 being up with respect to the impeller 10. The vertical direction is simply a name used for explanation, and does not limit the actual positional relationship and direction. Further, “upstream” and “downstream” indicate upstream and downstream, respectively, in the flow direction of the air sucked from the intake port 3 when the impeller 10 is rotated.

  In the present specification, in the vacuum cleaner 100, the direction approaching the floor surface F (surface to be cleaned) in FIG. 1 is “downward” and the direction away from the floor surface F is “upward”. Will be explained. These directions are simply names used for explanation, and do not limit the actual positional relationship and direction. Further, “upstream” and “downstream” respectively indicate upstream and downstream in the flow direction of the air sucked from the air inlet 103 when the blower 1 is driven.

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

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

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

<2. Overall configuration of blower>
FIG. 2 is a perspective view of the blower 1 according to the present embodiment. FIG. 3 is a front view of the inside of the blower 1. The blower 1 is mounted on the vacuum cleaner 100 and sucks air.

  The blower 1 has a cylindrical fan casing 2 with a circular horizontal cross section, and the fan casing 2 houses an impeller 10 and a motor housing 21. The fan casing 2 has an upper case portion 2 a that covers the impeller 10 and a lower case portion 2 b that covers the motor housing 21.

  An air inlet 3 that opens in the vertical direction (axial direction) is provided in the upper portion (upper case portion 2a) of the fan casing 2. The intake port 3 is provided with a bell mouth 31 that is bent inward from the upper end and extends downward. Thereby, the diameter of the air inlet 3 becomes smaller smoothly from the upper side to the lower side. The upper part of the fan casing 2 covers the top of the impeller 10. Further, the lower surface of the fan casing 2 is opened in the vertical direction.

  The motor housing 21 houses the motor 20. A cylindrical motor housing 21 having a circular horizontal cross section houses a motor 20 (see FIG. 3) connected to the impeller 10. As the motor 20 rotates, the impeller 10 rotates in the rotation direction R around the central axis C extending vertically. More specifically, the motor 20 is disposed below the impeller 10 and rotates the impeller 10.

  In addition, the upper case part 2a and the lower case part 2b of the fan casing 2 may be configured by a single member or may be configured by different members from each other.

  FIG. 4 is a side sectional view of the blower 1. A flow path 5 (first flow path) is formed in the gap between the fan casing 2 and the motor housing 21. The flow path 5 communicates with the impeller 10 at the upper end (upstream end), and an exhaust port 4 is formed at the lower end (downstream end) of the flow path 5.

  An annular groove 21g that is recessed downward is provided on the upper surface of the motor housing 21. An impeller convex portion 11p that protrudes downward is provided on the lower surface of the base portion 11 of the impeller 10. At least a part of the impeller convex portion 11p is accommodated in the groove portion 21g.

<3. Motor configuration>
FIG. 5 is a perspective view of the blower 1 as viewed from above, and is cut by a horizontal cross section that passes above the inlet 21a. FIG. 6 is a plan sectional view passing through the inlet 21 a of the blower 1. As shown in FIG. 4, a motor 20 housed in a motor housing 21 is disposed below the impeller 10. The motor 20 is a so-called inner rotor type motor, and has a stator 24 and a rotor 28 facing each other.

  The stator 24 is disposed on the radially outer side of the rotor 28. The stator 24 has a stator core 24a and a plurality of coils (not shown). The stator core 24a is made of a laminated steel plate in which electromagnetic steel plates are laminated in the axial direction (vertical direction in FIG. 4), and has an annular core back 24b and a plurality of teeth 24t.

  The plurality of teeth 24t extend radially inward from the inner peripheral surface of the core back 24b toward the magnet (not shown) of the rotor 28 and are formed radially. Thereby, the plurality of teeth 24t are arranged in the circumferential direction. The coil is configured by winding a conductive wire around each tooth 24t via an insulator 24s.

  The inner peripheral surface and outer peripheral surface of the core back 24b are flat in the vicinity of the root of the tooth 24t. Thereby, it is possible to prevent the coil from collapsing while preventing the magnetic field lines from being disturbed. Further, the inner peripheral surface and the outer peripheral surface of the core back 24b other than the vicinity of the root of the tooth 24t are curved. Thereby, a gap GP (see FIGS. 5 and 6) is formed between at least a part of the core back 24 b and the inner surface of the motor housing 21. The gap GP is formed between the planar outer peripheral surface of the core back 24 b and the inner surface of the motor housing 21.

  A lead wire (not shown) is led out from the coil, and one end of the lead wire is connected to a drive circuit (not shown) on the substrate 80 disposed below the fan casing 2. Thereby, electric power is supplied to the coil. A capacitor 81 is mounted on the substrate 80.

  A disc-shaped lower lid 29 is disposed below the stator 24, and the lower surface of the motor housing 21 is covered with the lower lid 29. A protrusion 21b is provided on the inner surface of the motor housing 21, and an annular step 29t is provided on the lower lid 29 so as to face the lower surface of the protrusion 21b. A lower lid 29 is attached to the motor housing 21 by screwing a screw (not shown) penetrating the stepped portion 29t into the screw hole 21c of the protruding portion 21b. The lower lid 29 is provided with a plurality of outlets 29a penetrating in the axial direction.

  The rotor 28 is disposed on the radially inner side of the stator 24. The rotor 28 includes a cylindrical rotor housing 28a and a plurality of magnets (not shown). The plurality of magnets are disposed on the outer peripheral surface of the rotor housing 28a. The radially outer surface of each magnet faces the radially inner end surface of each tooth 24t. In the plurality of magnets, N-pole magnetic pole faces and S-pole magnetic pole faces are alternately arranged and arranged at equal intervals in the circumferential direction.

  Note that a single annular magnet may be used instead of the plurality of magnets. In this case, N poles and S poles may be alternately magnetized in the circumferential direction on the inner peripheral surface of the magnet. Further, the magnet and the rotor housing may be integrally formed of a resin containing magnetic powder.

  The rotor housing 28a holds a shaft 27 extending in the axial direction. The shaft 27 is supported by the upper and lower bearing portions 26 and rotates in the rotation direction R together with the rotor 28 about the central axis C. A boss portion 11 a is provided on the lower surface of the center portion of the base portion 11 of the impeller 10. The upper end of the shaft 27 is press-fitted into a hole 11b provided at the center (on the central axis C) of the boss 11a.

  The upper bearing portion 26 is disposed inside the core back 24 b in the radial direction, and the lower bearing portion 26 is disposed in the center portion of the lower lid 29. The upper bearing portion 26 is composed of a ball bearing, and the lower bearing portion 26 is composed of a sliding bearing. Note that the upper and lower bearing portions 26 may have other types of bearings.

  A plurality of inflow ports 21 a communicating with the flow path 5 are provided on the peripheral wall of the motor housing 21. The inflow port 21 a penetrates in the radial direction below the upper surface of the stator 24 fixed to the inner surface of the motor housing 21. In this embodiment, the inflow port 21a is arrange | positioned in the vicinity of each teeth 24t, and two are provided with respect to one teeth 24t.

  The motor housing 21 has a flow path 6 (second flow path) that extends upward from the inlet 21 a and communicates with a space JK above the stator 24. The flow path 6 includes a gap GP between the core back 24 b and the inner surface of the motor housing 21. The outer surface 24w (see FIG. 4) of the core back 24b constitutes the side surface of the flow path 6. The lower end of the flow path 6 is closed by a step portion 29 t of the lower lid 29. Thereby, all the airflow S which flowed into the flow path 6 goes upwards.

  Above the stator 24, the inner surface of the motor housing 21 tilts radially inward as it goes upward.

  That is, the blower 1 includes an impeller 10 that rotates around a central axis C that extends vertically. Further, the blower 1 includes a motor 20 that is disposed below the impeller 10 and has a stator 24 to rotate the impeller 10. The blower 1 includes a motor housing 21 that houses the stator 24. The blower device 1 includes a fan casing 2 that houses the impeller 10 and the motor housing 21 and forms a flow path 5 (first flow path) in a gap between the motor housing 21. The upper part of the fan casing 2 has an intake port 3 that covers the top of the impeller 10 and penetrates in the vertical direction, and an exhaust port 4 that communicates with the intake port 3 through the flow path 5 at the lower part of the fan casing 2. Provided. The motor housing 21 is provided with an inflow port 21 a that penetrates in the radial direction and communicates with the flow path 5 below the upper surface of the stator 24 fixed to the inner surface of the motor housing 21. The motor housing 21 has a flow path 6 (second flow path) that extends upward from the inlet 21 a and communicates with a space JK above the stator 24.

<4. Stator blade configuration>
A plurality of stationary blades 40 are provided on the outer peripheral surface 21 w of the motor housing 21. The stationary blade 40 is formed in a plate shape, and is inclined in a direction opposite to the rotation direction R of the impeller 10 as it goes upward. The stationary blade 40 is curved convexly on the impeller 10 side. The outer edges of the plurality of stationary blades 40 are in contact with the inner surface of the fan casing 2. The stationary blades 40 are juxtaposed in the circumferential direction, and guide the airflow S downward when the blower 1 is driven. The inflow port 21 a is provided below the upper end of the stationary blade 40.

  The upper edge 40h (see FIG. 3) of the stationary blade 40 extends upward as it goes outward in the radial direction. The vertical length of the outer end 40g (see FIG. 3) of the stationary blade 40 is longer than the vertical length of the inner end 40n (see FIG. 3) of the stationary blade 40. The outer end portion 40g is a portion extending in the vertical direction in contact with the inner surface of the fan casing 2. The inner end portion 40n is a portion extending in the vertical direction in contact with the outer peripheral surface 21w of the motor housing 21 on the radially inner side of the outer end portion 40g. An outer end 40b (see FIG. 3) at the lower edge of the stationary blade 40 is disposed below the inner end 40a (see).

  Moreover, the cross-sectional area Sk (refer FIG. 3) of the lower end of the flow path between the stationary blades 40 adjacent to the circumferential direction is wider than the cross-sectional area Sh (refer to FIG. 3) of the upper end. Thereby, the dynamic pressure of the air (airflow S) which distribute | circulates between the adjacent stationary blades 40 by the stationary blade 40 can be easily converted into a static pressure, and the ventilation efficiency of the air blower 1 can be improved.

<5. Impeller configuration>
FIG. 7 is a perspective view of the impeller 10. The impeller 10 is a so-called mixed flow impeller formed of a resin molded product, and includes a base portion 11 and a plurality of blades 12. The diameter of the base portion 11 increases as it goes downward. In other words, the impeller 10 has the base portion 11 whose diameter increases as it goes downward. That is, the base portion 11 gradually increases in diameter toward the lower side. As shown in FIG. 4, the upper end portion (tip portion) of the base portion 11 is disposed at substantially the same height as the lower end of the bell mouth 31.

  A hole 11b into which the shaft 27 of the motor 20 is press-fitted is provided at the center (on the central axis C) of the boss 11a of the base 11. Thereby, the boss | hub part 11a and the shaft 27 are connected, and the impeller 10 rotates to the rotation direction R (refer FIG. 2) centering | focusing on the central axis C. FIG.

  The plurality of blades 12 are juxtaposed in the circumferential direction on the outer peripheral surface 11 w of the base portion 11. In the present embodiment, the blades 12 are juxtaposed on the outer peripheral surface 11 w of the base portion 11 in the circumferential direction at a predetermined cycle, and are integrally formed with the base portion 11. The upper portion of the blade 12 is disposed in front of the rotation direction R with respect to the lower portion, and the outer end portion 12b is disposed in front of the rotation direction R with respect to the root 12a. Further, in the outer end portion 12b on the front surface 12p (pressure surface) arranged in front of the rotation direction R, the radial component of the unit normal vector NV1 of the upper end portion 12h is the unit of the lower end portion 12k with the outer peripheral side being the positive direction. It is smaller than the radial direction component of the normal vector NV2.

  In the present embodiment, the radial component of the unit normal vector NV1 is substantially 0, and the unit normal vector NV2 has a radial component toward the outer peripheral side. The radial component of the unit normal vector NV1 may be directed toward the inner periphery. When the radial components of the unit normal vector NV1 and the unit normal vector NV2 are directed toward the outer peripheral side, the absolute value of the radial component of the unit normal vector NV1 is smaller than the unit normal vector NV2.

  FIG. 8 is a plan view of the impeller 10. FIG. 9 is a plan sectional view passing through the lower end 12k of the impeller 10. As shown in FIG. FIG. 10 is a cross-sectional view of the upper end portion 12 h of the blade 12 of the impeller 10, which is cut in a cross section perpendicular to the outer peripheral surface 11 w of the base portion 11 along the circumferential direction. FIG. 11 is a cross-sectional view of the lower end portion 12k of the blade 12 of the impeller 10, and is cut along a cross section perpendicular to the outer peripheral surface 11w of the base portion 11 along the circumferential direction. The thickness Tk of the base 12a of the lower end portion 12k is larger than the thickness Th of the base 12a of the upper end portion 12h.

  That is, the impeller 10 includes a base portion 11 whose diameter increases toward the lower side and a plurality of blades 12 disposed on the outer peripheral surface 11w of the base portion 11. The upper part of the blade 12 is arranged forward of the rotational direction R with respect to the lower part. The thickness Tk of the base 12a of the lower end 12k is larger than the thickness Th of the base 12a of the upper end 12h.

  The lower edge 12u (see FIG. 3) of the blade 12 extends radially outward and upward from the root 12a. That is, the lower edge 12u of the blade 12 is inclined upward on the outer peripheral side.

  As shown in FIG. 12, the axial gap G1 between the inner edge of the lower edge 12u of the blade 12 and the inner edge of the upper edge of the stationary blade 40 is equal to the outer edge of the lower edge 12u of the blade 12 and the upper edge of the stationary blade 40. It is equal to the axial gap G2 with the outer end of. Thereby, the gap between the blade 12 and the stationary blade 40 can be made substantially constant in the radial direction. Further, the circumferential distance between the inner end and the outer end of the lower edge 12 u of the blade 12 is equal to the circumferential distance between the inner end and the outer end of the upper edge of the stationary blade 40. Note that “equal” includes not only strictly equal but also approximately equal.

  The curvature radius Rs of the base 12a of the suction surface 12s in the rearward direction R of the lower end 12k is larger than the curvature radius Rp of the base 12a of the front surface 12p (pressure surface) in the front of the rotation direction R of the blade 12.

  Further, in the negative pressure surface 12s of the blade 12, the circumferential inclination angle θh (see FIG. 10) of the upper end portion 12h with respect to the outer peripheral surface 11w of the base portion 11 is in the circumferential direction of the lower end portion 12k with respect to the outer peripheral surface 11w of the base portion 11. It is larger than the inclination angle θk (see FIG. 11).

<6. Relationship between Impeller Convex and Groove>
FIG. 13 is an enlarged cross-sectional view of a cross section (a cross section including the central axis C) along the radial direction of the peripheral portions of the motor housing 21 and the impeller 10. The impeller convex portion 11p and the groove portion 21g of the motor housing 21 face each other in the axial direction. The upper edge of the groove portion 21g is located above the lower end 11t of the impeller convex portion 11p. An outer peripheral end 21t on the upper surface of the motor housing 21 is an upper edge of the outer side in the radial direction of the groove 21g, and is disposed above the lower end 11t of the impeller convex portion 11p. The lower end 21k of the groove 21g is disposed below the outer peripheral end 21t on the upper surface of the motor housing 21.

  The lower surface of the base portion 11 (the outer peripheral surface 11s of the impeller convex portion 11p) extends downward from the outer edge 11g toward the radially inner side. That is, the lower surface of the base portion 11 is inclined downward from the outer edge 11g.

  An outer peripheral surface 11s of the impeller convex portion 11p extends radially inward and downward from the outer edge of the base portion 11. The radially outer side wall 21s of the groove 21g extends radially inward and downward from the upper end (the outer peripheral end 21t of the upper surface) of the outer peripheral surface 21w of the motor housing 21.

  The distance D1 of the gap between the radially outer side wall 21s of the groove 21g and the outer peripheral surface 11s of the impeller protrusion 11p is the same at the radially outer end and the radially inner end. “Same” includes not only exactly the same case but also substantially the same case.

  The inner peripheral surface 11n of the impeller convex portion 11p and the radially inner side wall 21n of the groove portion 21g extend radially inward and upward. The distance D2 between the inner peripheral surface 11n of the impeller convex portion 11p and the radially inner side wall 21n of the groove portion 21g is the distance between the outer peripheral surface 11s of the impeller convex portion 11p and the radially outer side wall 21s of the groove portion 21g. It is smaller than D1.

  Further, the upper surface of the motor housing 21 has a protruding portion 21p protruding upward, and the outer peripheral surface of the protruding portion 21p constitutes a radially inner side wall 21n of the groove portion 21g. The upper end of the protruding portion 21p is disposed above the lower end 11t of the impeller convex portion 11p. Further, the upper end of the protruding portion 21p is disposed above the upper end of the outer peripheral surface 21w of the motor housing 21 (the outer peripheral end 21t on the upper surface).

  In the cross section including the central axis C, the outer peripheral surface 11w of the base portion 11 and the outer peripheral surface 21w of the motor housing 21 are arranged on a straight line or a smooth curved line as indicated by a one-dot chain line L in the vicinity of the groove portion 21g.

  The radially outer side wall 21s of the groove portion 21 is parallel to a rotation surface formed of a conical surface obtained by rotating the lower edge 12u of the blade 12 around the central axis C (see FIG. 4). Further, the conical surface obtained by rotating the lower edge 12u of the blade 12 around the central axis C is perpendicular to the outer peripheral surface 11w of the base portion 11 on the vertical cross section including the central axis C, and the stationary blade 40 (see FIG. 3). It is parallel to the upper edge 40h. “Parallel” includes not only strictly parallel but also approximately parallel. “Orthogonal” includes not only strictly orthogonal but also substantially orthogonal.

<7. Operation of vacuum cleaner and blower>
In the vacuum cleaner 100 having the above configuration, when the motor 20 of the blower 1 is driven, the impeller 10 rotates in the rotation direction R about the central axis C. As a result, air containing dust such as dust on the floor surface F sequentially flows through the suction nozzle 110, the suction pipe 107, the suction port 103 (all refer to FIG. 1), the dust collection unit, and the filter. The air that has passed through the filter is taken into the fan casing 2 through the air inlet 3 of the blower 1. At this time, the air sucked from the inlet 3 is rectified by the bell mouth 31 and is smoothly guided between the adjacent blades 12. Therefore, the intake efficiency of the blower 1 can be improved.

  The air taken into the inside of the fan casing 2 flows between the adjacent blades 12 and is accelerated downward in the radial direction by the rotating impeller 10. Air that has accelerated downward in the radial direction is blown out below the impeller 10. Air (airflow S) blown downward from the impeller 10 flows into the flow path 5. The air flowing into the flow path 5 flows between the stationary blades 40 adjacent in the circumferential direction. At this time, the cross-sectional area Sk at the lower end of the flow path between the stationary blades 40 adjacent in the circumferential direction is wider than the cross-sectional area Sh at the upper end. For this reason, the dynamic pressure of the airflow S flowing through the flow path 5 is easily converted into a static pressure.

  The airflow S that has passed through the lower end of the stationary blade 40 is exhausted to the outside of the fan casing 2 through the exhaust port 4. The airflow S exhausted to the outside of the fan casing 2 flows through the air passage in the housing 102 of the cleaner 100 and is exhausted to the outside of the housing 102 from the exhaust port 104 (see FIG. 1). Thereby, the cleaner 100 can clean the floor surface F.

  At this time, a part of the airflow S flowing through the flow path 5 flows into the flow path 6 through the inflow port 21a. The airflow S that has flowed into the flow path 6 flows upward and flows into the space JK above the stator 24. The airflow S flowing into the space JK flows along the upper surface of the stator 24 and then descends through the gap between the rotor 28 and the teeth 24t and is exhausted from the outlet 29a of the lower lid 29. Thereby, it becomes difficult for the heat of the stator 24 to accumulate in the motor housing 21, and the cooling efficiency of the stator 24 can be improved.

  Further, the upper part of the blade 12 is arranged in front of the rotation direction R with respect to the lower part. Further, in the outer end portion 12b on the front surface 12p (pressure surface) arranged in front of the rotation direction R, the radial component of the unit normal vector NV1 of the upper end portion 12h is the unit of the lower end portion 12k with the outer peripheral side being the positive direction. It is smaller than the radial direction component of the normal vector NV2. Thereby, the air sucked from the intake port 3 can be smoothly guided to the flow path 5 below the impeller 10. Further, the thickness Tk of the base 12a of the lower end 12k is larger than the thickness Th of the base 12a of the upper end 12h. Thereby, the intensity | strength of the lower end part 12k of the blade | wing 12 to which a pressure becomes large with the air sent out at the time of rotation of the impeller 10 can be improved.

  An annular impeller convex portion 11 p is provided on the lower surface of the base portion 11, and an annular groove portion 21 g recessed downward is provided on the upper surface of the motor housing 21. At least a part of the impeller convex portion 11p is accommodated in the groove portion 21g. Thereby, inflow to the inner side (space SP, refer to Drawing 4) of impeller 10 of air current S which circulates channel 5 can be prevented, controlling size enlargement of blower 1 in the direction of an axis. That is, the labyrinth effect is exhibited. Therefore, the blowing efficiency of the blower 1 can be improved.

<8. First Modification>
FIG. 14 is a side sectional view of a modified example of the stationary blade 40. As shown in the figure, the lower end portion 40k of the pressure surface 40p of the stationary blade 40 may be inclined forward in the rotational direction R of the blade 12 as it goes downward. In addition, the pressure surface 40p shows the surface where the rotating blade | wing 12 approaches. The suction surface 40s of the stationary blade 40 is a surface on which the rotating blade 12 moves away. The airflow S along the pressure surface 40p is larger than the airflow S along the negative pressure surface 40s. Thereby, rapid peeling at the lower end portion 40k (downstream portion) of the stationary blade 40 of the airflow S along the pressure surface 40p of the stationary blade 40 can be reduced. Therefore, the backflow of the airflow S can be reduced.

<9. Second Modification>
As shown in FIG. 15, a plurality of concave portions 21d may be arranged in the vertical direction on the radially inner side wall 21n of the groove portion 21g. Thereby, when the impeller 10 rotates, the air between the inner peripheral surface 11n of the impeller convex portion 11p and the radially inner side wall 21n of the groove portion 21g easily enters the concave portion 21d. Therefore, the air viscous resistance with respect to the impeller 10 can be reduced, and the blowing efficiency of the blower 1 can be improved.

  Further, as shown in FIG. 16, the upper surface 21 v of the motor housing 21 may be smoothly curved so as to protrude outwardly above the stator 24. For example, above the stator 24, the inner surface of the motor housing 21 may be curved like the inner surface of the dome.

<10. Third Modification>
As shown in FIG. 17, the cross section SC perpendicular to the radial direction of the tooth 24t and the inflow port 21a may face each other in the radial direction. Thereby, the vicinity of the teeth 24t that are likely to become high temperature can be efficiently cooled. Further, it is desirable that the number of inflow ports 21a and the number of teeth 24t are the same. That is, if one inflow port 21a is provided for one tooth 24t, the vicinity of the tooth 24t that tends to become high temperature can be efficiently cooled while maintaining the strength of the motor housing 21.

<11. Effects of this embodiment>
According to the present embodiment, the motor housing 21 has an inflow port that penetrates in the radial direction and communicates with the flow path 5 (first flow path) below the upper surface of the stator 24 fixed to the inner surface of the motor housing 21. 21a is provided. The motor housing 21 has a flow path 6 (second flow path) that extends upward from the inlet 21 a and communicates with the space JK above the stator 24. Thereby, a part of the airflow S flowing through the flow path 5 flows into the flow path 6 through the inflow port 21a and is guided to the space JK. Therefore, the stator 24 of the motor 20 can be efficiently cooled.

  The stator 24 has an annular core back 24b. At least a part of the core back 24b forms a gap GP with the inner surface of the motor housing 21, and the flow path 6 includes the gap GP. Thereby, the flow path 6 is easily realizable, suppressing the enlargement of the air blower 1. FIG.

  The stator 24 has teeth 24t extending radially inward from the core back 24b. And the cross section perpendicular | vertical to the radial direction of the teeth 24t and the inflow port 21a may oppose radial direction. Thereby, the vicinity of the teeth 24t that are likely to become high temperature can be efficiently cooled.

  The number of inflow ports 21a and the number of teeth 24t are preferably the same. Thereby, the vicinity of the teeth 24t that are likely to become high temperature can be efficiently cooled while maintaining the strength of the motor housing 21.

  The outer surface of the core back 24 b constitutes the side surface of the flow path 6. Thereby, the vicinity of the core back 24b can be efficiently cooled.

  Above the stator 24, the inner surface of the motor housing 21 tilts radially inward as it goes upward. Thereby, the airflow S can be smoothly guided to the central portion of the motor 20.

  In addition, above the stator 24, the inner surface of the motor housing 21 may be smoothly curved so as to protrude outward. For example, above the stator 24, the inner surface of the motor housing 21 may be curved like the inner surface of the dome. Thereby, the airflow S can be smoothly guided by the central part of the motor 20.

  A lower lid 29 covering the lower side of the motor housing 21 is provided, and the lower lid 29 is provided with an outlet 29a penetrating in the axial direction. Thereby, the air heated by cooling the stator 24 can be easily exhausted from the outlet 29a. Therefore, the cooling efficiency of the stator 24 can be further improved.

  A plurality of stationary blades 40 arranged in the circumferential direction are provided on the outer peripheral surface 21 w of the motor housing 21, and the inlet 21 a is provided below the upper end of the stationary blade 40. Thereby, a part of the airflow S flowing through the flow path 5 is smoothly guided into the flow path 6 through the inflow port 21a. Therefore, the cooling efficiency of the stator 24 can be further improved.

  The cross-sectional area Sk at the lower end of the flow path between the stationary blades 40 adjacent in the circumferential direction is wider than the cross-sectional area Sh at the upper end. Thereby, the dynamic pressure of the airflow S flowing through the flow path 5 is easily converted into a static pressure, and a part of the airflow S flowing through the flow path 5 is more smoothly guided to the flow path 6 through the inflow port 21a. .

  The inflow port 21a may be provided below the stator 24. Thereby, the inside of the motor 20 is easily cooled via the stator 24.

  Since the vacuum cleaner 100 has the air blower 1, the vacuum cleaner 100 which improved the cooling efficiency of the stator 24 of the air blower 1 can be implement | achieved easily.

  The impeller 10 includes a base portion 11 whose diameter increases toward the lower side and a plurality of blades 12 arranged on the outer peripheral surface 11w of the base portion 11. The upper part of the blade 12 is arranged forward of the rotational direction R with respect to the lower part. In the outer end portion 12b on the front surface 12p (pressure surface) disposed in front of the rotation direction R, the radial component of the unit normal vector NV1 of the upper end portion 12h is the unit normal of the lower end portion 12k with the outer peripheral side being the positive direction. It is smaller than the radial component of the vector NV2. Thereby, the air sucked from the intake port 3 can be smoothly guided to the flow path 5 below the impeller 10. Further, the thickness Tk of the base 12a of the lower end 12k is larger than the thickness Th of the base 12a of the upper end 12h. Thereby, the intensity | strength of the lower end part 12k of the blade | wing 12 to which a pressure becomes large with the air sent out at the time of rotation of the impeller 10 can be improved. Furthermore, when the impeller 10 is molded by pulling a die (not shown) disposed between adjacent blades 12 radially outward and downward, the blades 12 can be prevented from being damaged. Therefore, the mass productivity of the blower 1 can be improved.

  The lower edge of the blade 12 extends radially outward and upward from the base 12a. Thereby, the air which circulated between the blades 12 of the impeller 10 can be easily guided downward (exhaust side). Therefore, the blowing efficiency of the blower 1 can be improved.

  The motor housing 21 that covers the motor 20 and has a plurality of stationary blades 40 disposed on the outer peripheral surface 21w is provided. The upper edge 40h of the stationary blade 40 extends upward as it goes radially outward. Thereby, the air sent out from the impeller 10 can be made to follow the stationary blade 40 without waste, and the ventilation efficiency of the air blower 1 can be improved.

  The lower edge 12u of the blade 12 extends upward as it goes radially outward, and the axial gap G1 between the inner end of the lower edge 12u of the blade 12 and the inner edge of the upper edge of the stationary blade 40 is the lower edge of the blade 12 It is equal to the axial gap G2 between the outer end of 12u and the outer end of the upper edge of the stationary blade 40. Thereby, the radial gap between the blade 12 and the stationary blade 40 can be made substantially constant. Therefore, the pressure distribution in the flow path 5 can be made uniform and the blowing efficiency of the blower 1 can be improved.

  The circumferential distance between the inner end and the outer end of the lower edge 12 u of the blade 12 is equal to the circumferential distance between the inner end and the outer end of the upper edge of the stationary blade 40. Thereby, the clearance in the circumferential direction between the blade 12 and the stationary blade 40 can be made substantially constant. Therefore, the pressure distribution in the flow path 5 can be made more uniform, and the blowing efficiency of the blower 1 can be improved.

  The vertical length of the outer end 40g of the stationary blade 40 is longer than the vertical length of the inner end 40n of the stationary blade 40. Thereby, the stationary blade 40 can be lengthened on the outer peripheral side of the flow path 5, and air can be guided downward without waste.

  The outer end 40b of the lower edge of the stationary blade 40 is disposed below the inner end 40a. Thereby, the stationary blade 40 can be lengthened on the outer peripheral side of the flow path 5, and air can be guided downward without waste.

  The lower end portion 40k of the pressure surface 40p of the stationary blade 40 may be inclined forward in the rotational direction R of the blade 12 as it goes downward. Thereby, the rapid peeling at the lower end portion 40k of the stationary blade 40 of the airflow S along the pressure surface 40p (surface on which the blade 12 approaches) of the stationary blade 40 can be reduced. Therefore, the backflow of the airflow S can be reduced.

  The lower surface of the base portion 11 extends downward from the outer edge 11g toward the inner side in the radial direction. Thereby, the thickness of the base part 11 of the impeller 10 can be ensured substantially uniformly even at the lower end part. Therefore, the strength of the impeller 10 can be improved.

  The curvature radius Rs of the root 12a of the suction surface 12s of the blade 12 is larger than the curvature radius Rp of the root 12a of the front surface 12p (pressure surface) of the blade 12. Thereby, the intensity | strength of the root 12a of the blade | wing 12 can be improved easily, suppressing the fall of the ventilation efficiency of the air blower 1. FIG. Further, when the mold disposed between the adjacent blades 12 is pulled out radially outward and downward, interference between the mold and the lower end portion 12k of the blade 12 can be prevented, and the mold is easily pulled out. be able to.

  In the negative pressure surface 12 s of the blade 12, the circumferential inclination angle θh of the upper end portion 12 h with respect to the outer peripheral surface 11 w of the base portion 11 is larger than the circumferential inclination angle θk of the lower end portion 12 k with respect to the outer peripheral surface 11 w of the base portion 11. This prevents interference between the mold and the lower end portion 12k of the blade 12 when the mold disposed between the adjacent blades 12 is pulled outward in the radial direction and downward. Can be removed.

  An annular impeller convex portion 11 p is provided on the lower surface of the base portion 11, and an annular groove portion 21 g that is recessed downward is provided on the upper surface of the motor housing 21. At least a part of the impeller convex portion 11p is accommodated in the groove portion 21g. Thereby, inflow to the inner side of the impeller 10 of the airflow S which distribute | circulates the flow path 5 can be prevented, suppressing the enlargement of the axial direction of the air blower 1. FIG. That is, the labyrinth effect is exhibited. Therefore, the blowing efficiency of the blower 1 can be improved.

  The outer peripheral end 21t on the upper surface of the motor housing 21 is disposed above the lower end 11t of the impeller convex portion 11p. Thereby, the labyrinth effect of the air blower 1 can be improved.

  The lower end 21k of the groove 21g is disposed below the outer peripheral end 21t on the upper surface of the motor housing 21. Thereby, the increase in the axial direction length of the air blower 1 can be suppressed easily.

  The outer peripheral surface 11s of the impeller convex portion 11p extends radially inward and downward from the outer edge of the base portion 11, and the radially outer side wall 21s of the groove portion 21g is the upper end (the outer peripheral end 21t of the upper surface) of the outer peripheral surface 21w of the motor housing 21. ) Extending radially inward and downward. Thereby, contact with the rotating impeller 10 and the side wall 21s (inner wall) of the groove 21g can be easily prevented while exhibiting the labyrinth effect.

  The distance D1 of the gap between the radially outer side wall 21s of the groove 21g and the outer peripheral surface 11s of the impeller protrusion 11p is the same at the radially outer end and the radially inner end. Thereby, the labyrinth effect of the air blower 1 can be improved.

  The inner peripheral surface 11n of the impeller convex portion 11p and the radially inner side wall 21n of the groove portion 21g extend radially inward and upward, and the inner peripheral surface 11n of the impeller convex portion 11p and the radially inner side wall 21n of the groove portion 21g. The gap distance D2 is smaller than the gap distance D1 between the outer peripheral surface 11s of the impeller convex portion 11p and the radially outer side wall 21s of the groove portion 21g. Thereby, the labyrinth effect can be further improved while easily preventing contact between the rotating impeller 10 and the side walls 21s and 21n (inner walls) of the groove 21g.

  A plurality of concave portions 21d may be arranged in the vertical direction on the radially inner side wall 21n of the groove portion 21g. Thereby, when the impeller 10 rotates, the air between the inner peripheral surface 11n of the impeller convex portion 11p and the radially inner side wall 21n of the groove portion 21g easily enters the concave portion 21d. Therefore, the air viscous resistance with respect to the impeller 10 can be reduced, and the blowing efficiency of the blower 1 can be improved.

  The upper surface of the motor housing 21 has a protruding portion 21p protruding upward, and the outer peripheral surface of the protruding portion 21p constitutes a radially inner side wall 21n of the groove portion 21g. Thereby, the labyrinth effect can be improved easily.

  The upper end of the protruding portion 21p is disposed above the lower end 11t of the impeller convex portion 11p. Thereby, the labyrinth effect can be improved more easily.

  The upper end of the protrusion 21p is disposed above the upper end of the outer peripheral surface of the motor housing 21 (the outer peripheral end 21t on the upper surface). Thereby, a labyrinth effect can be improved more.

  In the cross section including the central axis C, the outer peripheral surface 11w of the base portion 11 and the outer peripheral surface 21w of the motor housing 21 are arranged on a straight line or a smooth curve in the vicinity of the groove portion 21g. Thereby, circulation of the air in the flow path 5 can be made smooth, providing the groove part 21g.

  A radially outer side wall 21 s of the groove portion 21 is parallel to the rotation surface of the lower edge 12 u of the blade 12. Thereby, the approach of the airflow S to the clearance gap between the impeller convex part 11p and the side wall 21s (inner wall) of the groove part 21g can be further prevented.

  On the cross section SC including the central axis C, the rotational surface of the lower edge 12u of the blade 12 is orthogonal to the outer peripheral surface 11w of the base portion 11. Thereby, the approach of the airflow S to the gap between the impeller convex portion 11p and the side wall 21s (inner wall) of the groove portion 21g can be further prevented.

  A plurality of stationary blades 40 arranged in the circumferential direction are provided on the outer peripheral surface 21 w of the motor housing 21, and the upper edge 40 h of the stationary blade 40 is parallel to the rotation surface of the lower edge 12 u of the blade 12. Thus, the air flowing between the adjacent blades 12 is made downward (exhaust side) of the flow path 5 while preventing the airflow S from entering the gap between the impeller convex portion 11p and the side wall 21s (inner wall) of the groove portion 21g. It can be sent out efficiently.

  The vacuum cleaner 100 has the air blower 1 described above. Thereby, the vacuum cleaner which has a ventilation device with high ventilation efficiency is realizable. In addition, in this embodiment, although the air blower 1 is mounted in the cleaner 100, the air blower 1 is mounted in various OA equipment, medical equipment, transport equipment, household electric appliances other than the vacuum cleaner 100, etc. May be.

  According to this invention, it can utilize for an air blower and a vacuum cleaner provided with the same.

DESCRIPTION OF SYMBOLS 1 ... Blower, 2 ... Fan casing, 2a ... Upper case part, 2b ... Lower case part, 3 ... Intake port, 4 ... Exhaust port, 5 ... Flow path (First flow path), 6 ... flow path (second flow path), 10 ... impeller, 11 ... base portion, 11a ... boss portion, 11b ... hole portion, 11g ... · Outer edge, 11n ··· inner peripheral surface, 11p ··· impeller convex portion, 11s ··· outer peripheral surface, 11t ··· lower end, 11w · · · outer peripheral surface, 12 ··· blades, 12a · · · root 12b: outer end, 12h: upper end, 12k ... lower end, 12p ... front surface (pressure surface), 12s ... negative pressure surface, 12u ... lower edge, 20 ... -Motor, 21 ... Motor housing, 21a ... Inlet, 21b ... Projection, 21c ... Screw hole, 21d ... Recess, 21g · Groove portion, 21k ··· lower end, 21n ··· side wall, 21p ··· projection, 21s ··· side wall, 21t ··· outer peripheral end, 21v ··· inner surface, 21w ··· outer peripheral surface, 24 · .., stator, 24a ... stator core, 24b ... core back, 24s ... insulator, 24t ... teeth, 24w ... outer surface, 26 ... bearing, 27 ... shaft, 28 .... Rotor, 28a ... Rotor housing, 29 ... Lower lid, 29a ... Outlet, 29t ... Stepped portion, 31 ... Bellmouth, 40 ... Stator blade, 40a ... Inner end, 40b ... outer end, 40g ... outer end, 40h ... upper edge, 40n ... inner end, 40p ... pressure surface, 40s ... negative pressure surface, 80 ...・ Board, 81... Capacitor, 100... Vacuum cleaner, 102. , 103 ... intake port, 104 ... exhaust port, 105 ... gripping part, 106 ... operation part, 106a ... button, 107 ... suction pipe, 110 ... suction nozzle, C ... Center axis, D1 ... Distance, D2 ... Distance, F ... Floor, GP ... Gap, JK ... Space, L ... Dash-dotted line, NV1 ... Normal Vector, NV2 ... normal vector, R ... rotational direction, Rp ... radius of curvature, Rs ... radius of curvature, S ... airflow, SP ... space, Sh ... cross-sectional area, Sk ... cross-sectional area, Th ... thickness, Tk ... thickness

Claims (16)

A blower,
An impeller rotating around a central axis extending vertically;
A motor arranged below the impeller to rotate the impeller;
A motor housing that houses the motor;
A fan casing that houses the impeller and the motor housing and forms a flow path in a gap with the motor housing;
With
The upper portion of the fan casing includes an intake port that covers the top of the impeller and opens in the vertical direction,
At the lower part of the fan casing, an exhaust port communicating with the intake port via the flow path is provided,
The impeller has a base portion whose diameter increases as it goes downward, and a plurality of blades juxtaposed in the circumferential direction on the outer peripheral surface of the base portion,
An annular impeller convex portion is provided on the lower surface of the base portion,
An annular groove recessed downward is provided on the upper surface of the motor housing,
An air blower in which at least a part of the convex portion is accommodated in the groove portion.   The blower device according to claim 1, wherein an outer peripheral end of an upper surface of the motor housing is disposed above a lower end of the convex portion.   The blower according to claim 1 or 2, wherein a lower end of the groove is disposed below an outer peripheral end of an upper surface of the motor housing. The outer peripheral surface of the convex portion extends radially inward and downward from the outer edge of the base portion,
4. The blower according to claim 1, wherein a radially outer side wall of the groove portion extends radially inward and downward from an outer peripheral end of an upper surface of the motor housing.   The air blower according to claim 4, wherein a distance between a radially outer side wall of the groove portion and an outer peripheral surface of the convex portion is the same at the radially outer end portion and the radially inner end portion. The inner peripheral surface of the convex portion and the radially inner side wall of the groove portion extend radially inward and upward,
The distance of the clearance gap between the inner peripheral surface of the said convex part and the radial direction inner side wall of the said groove part is smaller than the distance of the clearance gap between the outer peripheral surface of the said convex part, and the radial direction outer side wall of the said groove part. Or the air blower of Claim 5.   The blower according to claim 6, wherein a plurality of concave portions are arranged in a vertical direction on a radially inner side wall of the groove portion.   The upper surface of the motor housing has a protruding portion that protrudes upward, and an outer peripheral surface of the protruding portion constitutes a radially inner side wall of the groove portion. Blower device.   The blower according to claim 8, wherein an upper end of the protruding portion is disposed above a lower end of the convex portion.   The blower according to claim 8 or 9, wherein an upper end of the protrusion is disposed above an outer peripheral end of an upper surface of the motor housing.   11. The cross section including the central axis, wherein the outer peripheral surface of the base portion and the outer peripheral surface of the motor housing are arranged on a straight line or a smooth curve in the vicinity of the groove portion. The blower described in 1.   The blower according to any one of claims 1 to 11, wherein a radially outer side wall of the groove is parallel to a rotation surface of a lower edge of the blade.   The air blower according to claim 12, wherein the rotating surface is orthogonal to a peripheral surface of the base portion on a cross section including the central axis. A plurality of stationary blades arranged side by side in the circumferential direction are provided on the outer peripheral surface of the motor housing,
The blower according to claim 12 or 13, wherein an upper edge of the stationary blade is parallel to the rotating surface.   The blower device according to claim 14, wherein a cross-sectional area at a lower end of a flow path between the stationary blades adjacent in the circumferential direction is wider than a cross-sectional area at an upper end.   The vacuum cleaner which has a ventilation device in any one of Claims 1-15.