WO2011027519A1

WO2011027519A1 - Electric air blower and electric cleaner utilizing same

Info

Publication number: WO2011027519A1
Application number: PCT/JP2010/005257
Authority: WO
Inventors: 誠村上; 博之香山; 一繁中村; 健一渡邉
Original assignee: パナソニック株式会社
Priority date: 2009-09-02
Filing date: 2010-08-26
Publication date: 2011-03-10
Also published as: JP2011052591A

Abstract

Disclosed is an electric air blower comprised of a motor, an impeller, a motor case, and a fan case, wherein a stator is comprised of a molded portion obtained by molding a core and a coiled wire using a resin; a plurality of guide vanes which are projected from the molded portion and which extend into an air passage, and the stator are integrally molded; and the plurality of guide vanes form a plurality of airways in the air passage.

Description

Electric blower and electric vacuum cleaner using the same

The present invention relates to an electric blower and a vacuum cleaner using the same.

Conventionally, electric blowers that have a small motor cooling and low pressure loss are widely used in household vacuum cleaners (see, for example, Patent Documents 1 to 3). The input power of the vacuum cleaner is limited, and it is necessary to improve the blowing performance of the electric blower in order to obtain a stronger suction force. At the same time, from the viewpoint of ease of cleaning, it is desirable that the vacuum cleaner body is small, and it is necessary to reduce the size of the electric blower.

FIG. 12 is a cross-sectional view of a conventional electric blower for a vacuum cleaner described in Patent Document 1. The electric blower 35 of Patent Document 1 includes an impeller 29, an air guide 30, an electric motor 32, and a hub 33, and is configured such that an airflow that flows out of the impeller 29 passes through an outer frame 34 of the electric motor 32. . Here, the impeller 29 has a mixed flow type blade 28. The air guide 30 is disposed on the downstream side of the impeller 29. In the motor 32, an impeller 29 is fixed to the shaft end of the rotating shaft 31. The hub 33 is provided at the shaft end of the rotating shaft 31.

FIG. 13 is a cross-sectional view of another conventional electric blower described in Patent Document 2. The electric blower 50 of Patent Document 2 includes a motor including a rotor 37, a stator 38, a bearing 39, and a frame 40, and includes an impeller 42, an air guide 43, and a fan case 45. ing. Here, the rotor 37 has a rotation shaft 36. The stator 38 has a winding. The bearing 39 supports the rotating shaft 36. The frame 40 includes a stator 38 and holds a bearing 39. The impeller 42 has a plurality of blades 41 and is fixed to the rotary shaft 36. The air guide 43 is disposed on the outer periphery of the impeller 42. The fan case 45 has a suction port 44 in the front center portion and includes an impeller 42 and an air guide 43 and is fixed to the frame 40.

And in patent document 2, the air flow path 47 is formed between the flame | frame 40 and the outer cylinder 46 provided in the outer side, The air flow which generate | occur | produced in the impeller 42 is guide | induced to the air guide 43 along the outer periphery of the flame | frame 40. I try to make it flow. Further, in Patent Document 2, a driving semiconductor element 48 is installed outside the outer cylinder 46, and a cooling fin 49 is provided inside the outer cylinder 46, the other end abutting against the frame 40, and the airflow matches the longitudinal direction. ing. The cross-sectional area of the independent passage surrounded by the cooling fin 49, the outer cylinder 46, and the frame 40 is formed such that the frame 40 or the outer cylinder 46 that gradually expands in the downstream direction is inclined.

FIG. 14 is a cross-sectional view of still another conventional electric blower described in Patent Document 3. The electric blower 54 of Patent Document 3 includes an electric motor 51, a fan 52, and a rectifying plate 53. The electric blower 54 further includes a switching element 55, the rectifying plate 53 is formed of a material having high heat conductivity, and the switching element 55 is fixed to the rectifying plate 53 in close contact. The fan 52 is rotationally driven by the electric motor 51. The rectifying plate 53 rectifies the airflow from the fan 52 and has a diffuser action. The switching element 55 controls the rotation speed of the electric blower 54.

However, in the configuration of the electric blower 35 of Patent Document 1, the air guide 30 and the electric motor 32 are configured separately. Therefore, the heat generated inside the electric motor 32 is not sufficiently conducted to the stationary blades of the air guide 30. As a result, the inside of the electric motor 32 has a problem that it is not sufficiently cooled.

Further, in the configuration of the electric blower 50 of Patent Document 2, the air flow generated in the impeller 42 takes the heat of the cooling fins 49 to cool the driving semiconductor element 48. However, since a part of the frame 40 of the motor and a part of the cooling fin 49 are only partially in contact with each other, the thermal contact resistance is large. Since the heat generated inside the electric motor is difficult to conduct to the cooling fins 49, there is a problem that the inside of the electric motor cannot be sufficiently cooled as in Patent Document 1.

Furthermore, in the configuration of the electric blower 54 of Patent Document 3, the rectifying plate 53 is used as a heat radiating plate of the switching element 55 by a material having high thermal conductivity. However, there is no description about the cooling of the electric motor 51, and a cooling means such as flowing cooling air inside the electric motor 51 is required separately. As a result, there is a problem that the size of the electric blower 54 is increased.

Japanese Patent Laying-Open No. 2005-307985 (FIG. 11) Japanese Patent Laid-Open No. 11-336696 (FIG. 4) JP 63-97130 A (Fig. 2)

The present invention relates to a rotor having a rotating shaft, a stator disposed on the outer periphery of the rotor, a motor configured to hold a bearing of the rotating shaft and cover the stator, an impeller fixed to the rotating shaft, and an outer peripheral surface of the stator And a fan case that covers the impeller and is fixed to the motor case. The stator is formed by molding a core and a winding with resin. A plurality of guide vanes that are configured and project from the mold portion and extend into the air passage and the stator are integrally formed, and the plurality of guide vanes are electric blowers that form a plurality of air passages in the air passage.

When the motor is driven, heat generated in the stator windings and the core is easily conducted to a plurality of guide blades integrally formed with the mold part. The airflow generated in the impeller is smoothly guided to the air passage, forcibly cooling the guide blades, and heat can be efficiently released to the outside of the motor. And since a some guide blade acts as a diffuser, while cooling a motor, the dynamic pressure of airflow can be converted into a static pressure.

In addition, since the impeller is rotationally driven by the motor, the motor itself can reduce heat generation, enable high-speed rotation by driving with large electric power, and realize a small and high-performance electric blower.

FIG. 1 is a partial cross-sectional view of the electric blower according to Embodiment 1 of the present invention. FIG. 2 is a partial cross-sectional perspective view of the electric blower. FIG. 3 is a partial cross-sectional perspective view of the impeller of the electric blower. FIG. 4 is a partial cross-sectional perspective view of the brushless motor of the electric blower. FIG. 5 is a partial cross-sectional perspective view of a stator of the electric blower. FIG. 6 is a cross-sectional view illustrating a configuration of a vacuum cleaner using the electric blower. FIG. 7 is a partial cross-sectional perspective view of the electric blower. FIG. 8 is a partial cross-sectional view of the electric blower according to Embodiment 2 of the present invention. FIG. 9 is a partial sectional perspective view of the electric blower. FIG. 10 is a partial cross-sectional perspective view of the brushless motor of the electric blower. FIG. 11 is a partial cross-sectional perspective view of a stator of the electric blower. FIG. 12 is a cross-sectional view of a conventional electric blower. FIG. 13 is a cross-sectional view of another conventional electric blower. FIG. 14 is a cross-sectional view of still another conventional electric blower.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a partial cross-sectional view of the electric blower according to Embodiment 1 of the present invention, FIG. 2 is a partial cross-sectional perspective view of the electric blower, FIG. 3 is a partial cross-sectional perspective view of the impeller of the electric blower, and FIG. FIG. 5 is a partial sectional perspective view of a brushless motor of the electric blower, and FIG. 5 is a partial sectional perspective view of a stator of the electric blower.

As shown in FIGS. 1 to 4, the electric blower 1a includes a brushless motor 7a, an impeller 8, a motor case 10a, and a fan case 11. Here, the brushless motor 7a includes a rotor 3 having a rotating shaft 2, a stator 4a disposed on the outer periphery of the rotor 3, and a frame 6 that holds the bearing 5 of the rotating shaft 2 and covers the stator 4a. The impeller 8 is fixed to the rotating shaft 2. The impeller 8 has six mixed flow type blades 8 a formed by a three-dimensional curved surface fixed to the rotary shaft 2. The motor case 10a is disposed with a space serving as the air passage 9 between the outer periphery of the stator 4a. The fan case 11 covers the impeller 8 and is fixed to the upstream side of the air passage 9, that is, the motor case 10 a. And the stator 4a is comprised by the mold part 13a which shape-molded the core 12a and the coil | winding wound around the core 12a with resin. The upstream side of the air passage 9 means the impeller 8 side, and the downstream side of the air passage 9 means the bearing 5 side.

As shown in FIG. 5, the stator 4a is formed with a plurality of guide vanes 14a extending from the mold portion 13a and extending into the air passage 9. The plurality of guide vanes 14a are arranged on the outer periphery of the stator 4a so that the longitudinal direction is inclined from the axial direction and becomes spiral. As shown in FIG. 2, a plurality of independent passages 15 a are formed in the air passage 9 by the guide blades 14 a coming into contact with the inner wall of the motor case 10 a. That is, the plurality of guide vanes 14 a form a plurality of air passages (independent passages 15 a) in the air passage 9. As a result, the heat radiation area of the guide vanes 14a is expanded and the cooling effect of the brushless motor 7a of FIG. 1 is improved. Moreover, since the airflow from the impeller 8 is smoothly guided and the dynamic pressure of the airflow can be converted into static pressure in the air passage 9, a small and high-performance electric blower can be realized.

Further, the plurality of guide vanes 14 a from the upstream side to the downstream side of the air passage 9 have a spiral shape with the rotary shaft 2 as the center.

The motor case 10a has a conical shape that expands at a predetermined angle from the upstream side to the downstream side of the air passage 9. Accordingly, the sectional area of the independent passage 15a is continuously increased. As a result, the air passage 9 between the outer peripheral surface of the stator 4a and the motor case 10a can be continuously increased. The cross-sectional area of the air passage 9 can be easily adjusted according to the outer shape of the motor case 10a, and at the same time, the heat radiation area of the guide vanes 14a can be adjusted, so that the cooling configuration necessary for the brushless motor 7a can be easily realized. .

Further, the resin of the mold part 13a is filled with a filler in polyphenylene sulfide (PPS) to improve thermal conductivity. When the filler is filled in the resin, a heat conduction path serving as a heat path is formed inside the resin, and the thermal conductivity of the resin can be easily increased.

Further, the stator 4a is manufactured by injection molding of resin. The core 12a and the outer peripheral surface of the mold part 13a have substantially the same surface. As shown in FIG. 4, the frame 6 covering the front and rear surfaces of the mold part 13a holds the stator 4a on the outer peripheral surface of the stator 4a via three columns 6a. As shown in FIG. 1, the inlet tip of the impeller 8 and the suction port 11a of the fan case 11 are sealed via a ring 16 made of PTFE (Polytetrafluoroethylene) resin in a state where the impeller 8 is rotatable.

About the electric blower 1a comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. In FIG. 1, a rotating magnetic field is generated by exciting the windings of the stator 4a, the rotor 3 rotates in synchronization with the rotating magnetic field, and the impeller 8 fixed to the rotating shaft 2 rotates. The centrifugal force generated by the rotation of the impeller 8 pushes the air in the impeller 8 to the outer periphery in the impeller 8 and to the rear. And the inside of the impeller 8 becomes negative pressure, and the airflow A flowing into the impeller 8 from the front of the suction port 11a of the fan case 11 is generated. The airflow A flows in the axial direction of the rotary shaft 2 from the inlet tip of the impeller 8, flows along the six diagonal flow blades 8a, and then at an intermediate angle between the axial direction and the radial direction of the rotary shaft 2. It flows out of the impeller 8.

The airflow flowing out from the impeller 8 flows into the plurality of independent passages 15a formed in the guide blades 14a, flows along the outer peripheral surface of the stator 4a through the independent passages 15a, and flows out to the outer periphery of the electric blower 1a. Since the cross-sectional area of the independent passage 15a gradually increases from the upstream side to the downstream side of the air flow A, the dynamic pressure is converted into static pressure while the air flow A is decelerated. The blowing performance of the electric blower 1a is expressed by the ratio between the electric power input to drive the electric blower 1a and the work amount (the product of the degree of vacuum generated by the rotation of the impeller 8 and the flow rate) performed by the electric blower 1a. . For this reason, increasing the degree of vacuum (static pressure) generated by the electric blower 1a at the actual flow rate is important for improving the blowing performance of the electric blower 1a.

Since the mixed flow type impeller 8 causes the air flow A to flow out of the impeller 8 at an intermediate angle between the axial direction and the radial direction, the outer diameter can be made smaller than that of the centrifugal impeller 8. Further, the air passage on the diffuser side can be configured as a linear air passage with little pressure loss, and it is not necessary to provide a curved portion in the air passage, so that an air passage with little pressure loss can be formed.

Since this type of brushless motor 7a does not need to supply power by mechanically contacting the commutator and the armature unlike an AC commutator motor, it generates less heat than an AC commutator motor. Heat generation of the stator 4a occurs in both the winding and the core 12a, and Joule heat generated by current flowing through the winding is transmitted to the plurality of integrally formed guide vanes 14a by heat conduction through the mold portion 13a.

On the other hand, an eddy current is generated due to a change in the magnetic flux density of the core 12a due to a change in the magnetic field and a change in the magnetic flux passing through the core 12a, and the core 12a also generates heat. However, when the airflow generated in the impeller 8 flows along the outer peripheral surfaces of the plurality of guide vanes 14a and the stator 4a, heat is transferred from the guide vanes 14a and the outer peripheral surface of the stator 4a to the airflow. As a result, the heat generated in the stator 4a is transported outside the electric blower 1a, and the stator 4a is efficiently cooled.

In other words, the guide vane 14a has both a function of a diffuser that performs pressure recovery and a function as a heat radiating fin. With this configuration, not only the heat dissipation efficiency is improved, but also the brushless motor 7a is rotationally driven to reduce the amount of heat generated by the brushless motor 7a, thereby reducing the size of the electric blower 1a. .

Further, the guide vanes 14a are formed in a spiral shape around the rotating shaft 2 on the outer periphery of the stator 4a. Therefore, even in the limited length of the air passage 9, it is possible to increase the length of the independent passage 15a and expand the heat radiation area. Further, by integrally molding the mold portion 13a constituting the stator 4a and the guide blade 14a, the heat generated from the stator 4a is efficiently radiated, and the cooling effect of the electric blower 1a is greatly improved. Furthermore, since the independent passage 15a that can be used as a diffuser also becomes longer, the air blowing performance can be improved, and the sound insulation effect can be improved against noise propagating through the air passage 9, thereby realizing a small and low-noise electric blower 1a.

Particularly, the rotational noise of the electric blower 1a, which is a problem as annoying noise, is caused by harmonics including a frequency determined by the product of the number of blades of the impeller 8 and the rotational speed, and harmonics of the frequency. The harmonic is a noise in a high frequency range in the audible frequency range, and has straightness when the noise propagates. Therefore, the spiral guide vane 14a also functions as a sound insulation wall.

FIG. 6 is a cross-sectional view showing the configuration of the electric vacuum cleaner using the electric blower of Embodiment 1 of the present invention. If the

sound absorbing materials

25a and 25b in which the frequency range for absorbing sound is matched with the frequency range of rotational noise are arranged in the cleaner body 22, the noise reduction effect can be further enhanced.

It is desirable to use a resin with high thermal conductivity for the mold part 13a. The Joule heat generated in the windings can easily conduct heat to the plurality of guide blades 14a in the mold part 13a having improved thermal conductivity, and can be efficiently cooled by the airflow generated in the impeller 8. When the resin of the mold part 13a is filled with a highly heat conductive powder or a filler such as a fiber, the heat conductivity is improved. Specifically, nylon or liquid crystal polymer (LCP: Liquid Crystal Polymer) or the like may be filled in polyphenylene sulfide resin (PPS) as a filler.

As the conductive filler, metal powder, graphite, carbon black or the like can be used, and as the insulating filler, a sintered ceramic such as aluminum nitride, boron nitride or alumina can be used. Depending on the necessity of insulation of each part, you may use a filler properly. In the present embodiment, since the mold part 13a around the windings needs to be insulated, an insulating filler is used and the guide blades 14a are integrally molded.

However, it is desirable to use a resin blended with a conductive filler for the plurality of guide blades 14a functioning as heat radiation fins, and the thermal conductivity can be increased as compared with a resin blended with an insulating filler. For this reason, a method may be employed in which the winding peripheral part and the guide vane 14a are separately formed with a resin in which an insulating filler and a conductive filler are blended, and then combined. Moreover, what is necessary is just to obtain | require an optimal value experimentally about the mixture ratio of a filler.

Next, a vacuum cleaner using the above-described electric blower will be described with reference to FIG.

The electric vacuum cleaner 17 includes a vacuum cleaner body 22, a dust bag 23, an electric blower 1a, a soundproof cover 24, and

sound absorbing materials

25a and 25b. Here, the vacuum cleaner main body 22 has a dust collection chamber 19 communicating with the main body intake port 18 and a blower chamber 21 provided with a main body exhaust port 20. The dust bag 23 is attached to the dust collection chamber 19 with the main body inlet 18. The electric blower 1 a is installed in the blower chamber 21. The soundproof cover 24 covers the electric blower 1a and is made of flame retardant resin. The

sound absorbing materials

25 a and 25 b are arranged above and below the blower chamber 21. Although not shown, a hose and an extension pipe are sequentially connected to the main body inlet 18, and a nozzle for sucking dust on the floor surface is attached to the tip of the extension pipe.

With this configuration, when the impeller 8 of the electric blower 1a is rotated, the dust collection chamber 19 is in a negative pressure state, and an air flow including dust sucked from a nozzle (not shown) passes through the main body intake port 18 to collect the dust. It flows into the chamber 19. The clean airflow obtained by filtering and separating dust in the dust bag 23 flows into the impeller 8 of the electric blower 1a and passes through the air guide formed in the plurality of guide blades 14a. Thereafter, a clean airflow obtained by separating and filtering out dust flows out from the main body exhaust port 20 of the soundproof cover and is released to the outside of the cleaner main body 22.

The electric blower 1a mounted on the vacuum cleaner 17 has good heat dissipation as described above, and reduces the heat generation of the brushless motor 7a itself by rotationally driving the impeller 8 by the brushless motor 7a. As a result, the brushless motor 7a can be rotated at a high speed by being driven with large electric power. Moreover, the vacuum cleaner 17 has a strong suction force, and has a small size and a high blowing performance.

Therefore, the vacuum cleaner 17 is good at sucking dust with a strong suction force by mounting a small electric blower 1a having high blowing performance. Since the small electric blower 1a is light in weight, the vacuum cleaner 17 is easy to use because of its small turning.

Moreover, as shown in FIG. 6, by mounting the small electric blower 1a in the cleaner body 22, the space in which the

sound absorbing materials

25a and 25b can be arranged can be expanded. By increasing the installation area of the

sound absorbing materials

25a and 25b provided in the cleaner main body 22, the sound absorbing effect can be expanded and the operation sound of the vacuum cleaner 17 can be reduced. In addition, if the

sound absorbing materials

25a and 25b in which the sound absorption frequency range is matched with the frequency range of the rotational noise are arranged in the cleaner body 22, the noise reduction effect can be further enhanced. Furthermore, the resonance-type noise reduction structure that exhibits a significant noise reduction effect for the sound of a specific frequency is used in combination with the

sound absorbing materials

25a and 25b, so that the noise reduction effect against rotational noise can be greatly improved.

As described above, in the first embodiment, the stator 4a and the core 12a and the windings are molded with a resin having high thermal conductivity. The stator 4a is formed with a plurality of spiral guide vanes 14a extending from the mold portion 13a to the air passage 9 by integral molding. A plurality of guide vanes 14a are arranged on the outer periphery of the stator 4a so that the longitudinal direction thereof is the axial direction of the rotary shaft 2, and the guide vanes 14a are brought into contact with the inner wall of the motor case 10a so that a plurality of independent passages are formed in the air passage 9. 15a is formed. Thus, the airflow generated from the impeller 8 is smoothly guided to the independent passage 15a. Further, the heat generated in the winding and the core 12a is conducted to the plurality of guide vanes 14a. Therefore, the heat can be transferred from the guide blade 14a and the outer peripheral surface of the stator 4a to the air flow and released to the outside of the electric blower 1a, and the brushless motor 7a is efficiently cooled.

Further, since the plurality of independent passages 15a formed in the air passage 9 also has a diffuser action, it is possible to recover the static pressure of the airflow. And since the guide blade 14a functions as a sound insulation wall with respect to the rotational noise which generate | occur | produced in the impeller 8, it can reduce noise and can improve ventilation performance.

In the first embodiment, the case where the independent passage 15a is formed by bringing the plurality of guide blades 14a into contact with the inner wall of the motor case 10a has been described. However, it is desirable that the guide vanes 14a and the inner wall of the motor case 10a are bonded to each other without gaps, and the flow in the gaps between the independent passages 15a may be suppressed to smoothly flow the airflow.

Further, in the first embodiment, the case where the outer diameter of the motor case 10a is expanded from the upstream side to the downstream side of the air passage 9 by a predetermined angle and the sectional area of the independent passage 15a is gradually increased has been described. However, the torsion pitch in the axial direction of the rotating shaft 2 of the guide blade 14a having a spiral shape may be gradually increased toward the downstream side to increase the cross-sectional area of the independent passage 15a.

In the first embodiment, the fan case 11 is fixed to the motor case 10a to describe the outer case of the electric blower 1a. However, as shown in FIG. 7 which is a partial cross-sectional perspective view of the electric blower according to Embodiment 1 of the present invention, an outer case 26 in which a fan case and a motor case are integrally molded is used, and the outer periphery of the brushless motor 7a is surrounded by an outer case. The case 26 may cover the case.

(Embodiment 2)
8 is a partial sectional view of the electric blower according to Embodiment 2 of the present invention, FIG. 9 is a partial sectional perspective view of the electric blower, FIG. 10 is a partial sectional perspective view of a brushless motor of the electric blower, and FIG. FIG. 2 is a partial cross-sectional perspective view of a stator of the electric blower. In the second embodiment of the present invention, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

8 to 10, the electric blower 1b includes a stator 4b, a motor case 10b, and an air passage 9, and integrally forms a plurality of guide vanes 14b and a mold portion 13b. The plurality of guide vanes 14 b are arranged on the outer periphery of the stator 4 b so that the longitudinal direction is inclined with respect to the axial direction of the rotating shaft 2. The plurality of guide vanes 14b abut on the inner wall of the motor case 10b to form a plurality of independent passages 15b in the air passage 9. Here, the stator 4b is configured by a molded portion 13b in which a core 12b and a winding are molded with resin. The motor case 10 b has substantially the same diameter from the upstream side to the downstream side of the air passage 9. The air passage 9 is between the outer peripheral surface of the stator 4b and the motor case 10b. The plurality of guide blades 14b protrude from the mold part 13b, extend to the ventilation path 9, and have a plate shape.

And as shown in FIG. 9, FIG. 10, the thickness of the guide vane 14b decreases continuously from the upstream side to the downstream side of the air passage 9. As a result, the cross-sectional area of the independent passage 15b can be continuously increased without changing the outer shape of the motor case 10b. Therefore, it is possible to easily configure a small diffuser that also serves to cool the brushless motor 7b.

Further, the guide vanes 14b are configured such that the cross-sectional area of the independent passage 15b is gradually increased by shortening the length of every other guide vane 14b arranged on the outer periphery of the stator 4b. The frame 27 that holds the front and rear surfaces of the mold part 13b forms substantially the same surface as the stator 4b, and holds the stator 4b via the four support columns 27a.

About the electric blower 1b comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

First, the operation of the electric blower will be described. In FIG. 8, a rotating magnetic field is generated by exciting the winding, the rotor 3 rotates in synchronization with the rotating magnetic field, and the impeller 8 fixed to the rotating shaft 2 rotates. Due to the centrifugal force generated by the rotation of the impeller 8, the air in the impeller 8 is pushed to the outer periphery of the impeller 8 and rearward, and the inside of the impeller 8 becomes negative pressure, and an air flow A flowing into the impeller 8 from the front is generated. To do. The airflow A flows in the axial direction of the rotary shaft 2 from the inlet of the impeller 8, flows along the six diagonal flow blades, and then from the impeller 8 at an intermediate angle between the axial direction and the radial direction of the rotary shaft 2. leak.

The airflow that has flowed out of the impeller 8 flows into a plurality of independent passages 15b formed by the guide vanes 14b, flows along the outer peripheral surface of the stator 4b through the independent passages 15b, and flows out of the electric blower 1b. Since the cross-sectional area of the independent passage 15b increases from the upstream side to the downstream side of the airflow A, the dynamic pressure is converted into static pressure while the airflow is decelerated.

Heat generation of the stator 4b occurs in both the winding and the core 12b. When the airflow generated by the impeller 8 flows along the outer peripheral surfaces of the plurality of guide vanes 14b and the stator 4b, heat is transferred from the outer surfaces of the guide vanes 14b and the stator 4b to the airflow. As a result, the heat generated in the stator 4b is transported to the outside of the electric blower 1b, and the stator 4b is efficiently cooled. That is, since the guide vane 14b functions as a diffuser that performs pressure recovery and a function as a heat radiating fin, it is possible to reduce the size of the electric blower 1b.

In the second embodiment, since the guide blade 14b has a plate shape, it is easier to mold compared to the guide blade 14b having a curved surface like a spiral. Therefore, the number of blades that can be removed from the mold during injection molding can be increased. Moreover, since the guide blade 14b is plate-shaped, the heat radiation area of the guide blade 14b that functions as a heat radiation fin can be expanded. In addition, the cost can be reduced by simplifying the structure of the mold. In addition, since the core 12b only has a plurality of straight grooves, the core 12b can be manufactured by laminating the pressed electromagnetic steel sheets, and it is not necessary to have a complicated divided structure, and it is easy to manufacture.

The thickness of the guide blades 14b and the number of blades are the cross-sectional area required for the diffuser and the rate of change of the cross-sectional area for the plurality of independent passages 15b formed in the air passage 9, and the heat radiation area required for cooling the stator 4b. It is necessary to determine the optimum value experimentally.

As described above, in the second embodiment, the airflow generated from the impeller 8 is smoothly guided to the independent passage 15b. Further, the heat generated in the winding and the core 12b is conducted to the plurality of guide blades 14b, and the heat is transmitted from the outer surfaces of the guide blades 14b and the stator 4b to the air current, and can be released to the outside of the electric blower 1b. As a result, the brushless motor 7b can be efficiently cooled, and the guide blades 14b are plate-shaped, so that the mold configuration can be simplified, and the cooling performance can be improved by increasing the number of blades.

The configurations of the first embodiment and the second embodiment described above are not limited to this, and can be combined as appropriate.

As described above, the electric blower of the present invention improves heat dissipation from the stator, enables driving with large electric power, and obtains a small and high blowing performance. Applicable to vacuum cleaners.

DESCRIPTION OF

SYMBOLS

1a, 1b Electric blower 2 Rotating shaft 3

Rotor

4a, 4b Stator 5

Bearing

6, 27

Frame

6a,

27a Post

7a, 7b Brushless motor 8 Impeller 8a Diagonal blade 9

Air passage

10a, 10b Motor case 11 Fan case

11a Suction port

12a, 12b

Cores

13a,

13b Mold parts

14a,

14b Guide vanes

15a, 15b Independent passage 16 Ring 17 Vacuum cleaner 18 Main body intake port 19 Dust collection chamber 20 Main unit exhaust port 21 Blower chamber 22 Vacuum cleaner main unit 23 Dust collection bag 24

Soundproofing Cover

25a, 25b Sound absorbing material 26 Outer case

Claims

A motor including a rotor having a rotating shaft, a stator disposed on an outer periphery of the rotor, and a frame that holds a bearing of the rotating shaft and covers the stator;
An impeller fixed to the rotating shaft;
A motor case arranged by providing a space to be a ventilation path between the outer peripheral surface of the stator;
A fan case that covers the impeller and is fixed to the motor case;
The stator is configured by a mold part in which a core and a winding are molded by resin, and a plurality of guide vanes protruding from the mold part and extending into the air passage and the stator are integrally molded, and a plurality of the stators are formed. An electric blower characterized in that the guide vanes form a plurality of air passages in the air passage.
2. The electric blower according to claim 1, wherein the impeller includes a mixed flow type blade that causes an airflow flowing in from an inlet to flow out at an intermediate angle between an axial direction and a radial direction of the rotating shaft.
The electric blower according to any one of claims 1 and 2, wherein the mold part is formed of a polyphenylene sulfide resin.
The electric blower according to claim 3, wherein the resin is filled with a filler.
The plurality of guide vanes form an independent passage in the air passage by abutting against the inner wall of the motor case, and a cross-sectional area of the independent passage from upstream to downstream of the airflow generated by the rotation of the plurality of guide blades. The electric blower according to claim 1, wherein:
The electric blower according to claim 1, wherein the plurality of guide vanes are formed in a spiral shape on an outer periphery of the stator.
The electric blower according to claim 5, wherein the plurality of guide vanes are continuously reduced in thickness from upstream to downstream of the airflow.
The electric blower according to claim 5, wherein an outer diameter of the motor case is continuously increased from an upstream side to a downstream side of the air flow.
An electric vacuum cleaner equipped with the electric blower according to claim 1.