JP2011052591A - Electric blower and vacuum cleaner using the same - Google Patents

Abstract

An electric blower that efficiently cools a motor and has high blowing performance and a vacuum cleaner using the electric blower are provided.
A brushless motor 7a including a rotor 3 having a rotating shaft, a stator 4a disposed on the outer periphery of the rotor 3, a frame 6 that holds a bearing 5 of the rotating shaft 2 and covers the stator 4a, and a rotation A motor case 10a arranged with a space serving as an air passage 9 between the impeller 8 fixed to the shaft 2 and the outer peripheral surface of the stator 4a, and a fan case 11 that covers the impeller 8 and is fixed to the motor case 10a. The stator 4a is composed of a molded part in which a core and a winding are molded with resin, and is molded integrally with a plurality of guide blades 14a protruding from the molded part 13a and extending into the air passage. The plurality of guide vanes 14 a form a plurality of air passages in the air passage 9.
[Selection] Figure 1

Description

  The present invention relates to an electric blower that realizes cooling of a motor with a small size and low pressure loss and has high blowing performance, and a vacuum cleaner using the same.

  Conventionally, this type of electric blower has been 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 easy cleaning, it is desired that the vacuum cleaner body has a small turn, and it is necessary to reduce the size of the electric blower.

  FIG. 12 is a diagram showing a cross-sectional configuration of an electric blower for a vacuum cleaner described in Patent Document 1. As shown in FIG. As shown in FIG. 12, the electric blower 35 of Patent Document 1 includes an impeller 29 having a mixed flow type blade 28, an air guide 30 disposed on the downstream side of the impeller 29, and an impeller at the shaft end of the rotating shaft 31. The motor 32 to which the motor 29 is fixed and the hub 33 provided at the shaft end of the rotary shaft 31 are provided so that the airflow flowing out from the impeller 29 passes through the frame outside 34 of the motor 32.

  FIG. 13 is a diagram showing a cross-sectional configuration of the electric blower described in Patent Document 2. As shown in FIG. As shown in FIG. 13, the electric blower 50 of Patent Document 2 includes a rotor 37 having a rotating shaft 36, a stator 38 having a winding, a bearing 39 that supports the rotating shaft 36, and a stator 38. An impeller 42 having a plurality of blades 41 and fixed to the rotary shaft 36, and an air guide 43 disposed on the outer periphery of the impeller 42. And a fan case 45 having a suction port 44 in the front center portion and including the impeller 42 and the air guide 43 and fixed to the frame 40.

  A ventilation path 47 is formed between the frame 40 and the outer cylinder 46 provided on the outside thereof, and the air flow generated by the impeller 42 is guided to the air guide 43 and flows along the outer periphery of the frame 40. Then, a driving semiconductor element 48 is installed outside the outer cylinder 46, and a cooling fin 49 is provided inside the outer cylinder 46 so that the other end contacts the frame 40 and the longitudinal direction coincides with the air flow. The frame 40 or the outer cylinder 46 is inclined so that the sectional area of the independent passage surrounded by the fins 49, the outer cylinder 46, and the frame 40 gradually increases in the downstream direction.

  FIG. 14 is a diagram illustrating a cross-sectional configuration of the electric blower described in Patent Document 3. As illustrated in FIG. As shown in FIG. 13, the electric blower 54 of Patent Document 3 includes an electric motor 51, a fan 52 that is rotationally driven by the electric motor 51, and a rectifying plate 53 that rectifies the airflow from the fan 52 and has a diffuser action. The electric blower 54 and the switching element 55 for controlling the rotational speed of the electric blower 54 are formed, and the rectifying plate 53 is formed of a material having high thermal conductivity, and the switching element 55 is closely attached and fixed to the rectifying plate 53. Yes.

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

  However, in the configuration of the electric blower 35 of Patent Document 1, since the air guide 30 and the electric motor 32 are configured separately, the heat generated inside the electric motor 32 is sufficiently conducted to the stationary blades of the air guide 30. As a result, the interior of the motor 32 cannot be sufficiently cooled.

  Further, in the configuration of the electric blower 50 of Patent Document 2, the air flow generated by the impeller 42 takes the heat of the cooling fins 49, thereby enabling the driving semiconductor element 48 to be cooled. 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, and the heat generated inside the motor is difficult to conduct to the cooling fin 49. As in Patent Document 1, there is a problem that the inside of the electric motor cannot be sufficiently cooled.

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

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide an electric blower that efficiently cools a motor and has high blowing performance, and a vacuum cleaner using the same.

  In order to solve the above-described conventional problems, an electric blower of the present invention includes a rotor having a rotating shaft, a stator disposed on the outer periphery of the rotor, and a frame that holds a bearing of the rotating shaft and covers the stator. A brushless motor that is configured, an impeller that is fixed to the rotating shaft, a motor case that is provided with a space serving as an air passage between the outer peripheral surface of the stator, and a motor case that covers the impeller and is fixed to the motor case The stator is formed of a molded part in which a core and a winding are molded with resin, and integrally with a plurality of guide blades protruding from the molded part and extending into the air passage. The plurality of guide blades are molded to form a plurality of air passages in the air passage.

  As a result, when the brushless motor is driven, the heat generated in the stator winding and core is easily conducted to the guide blades integrally molded with the mold part, and the airflow generated by the impeller is smoothly guided to the air passage. By forcibly cooling the guide vanes, 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 an airflow can be converted into a static pressure. In addition, by rotating the impeller with a brushless motor, the motor itself can reduce heat generation, enabling high-speed rotation by driving with large electric power, and realizing an electric blower that is small and has high blowing performance.

  In addition, since the electric vacuum cleaner of the present invention is equipped with an electric blower that is small and has high blowing performance, it has a strong suction force and good dust removal, and since the electric blower is lightweight, it is easy to use with a small turn. Is a good vacuum cleaner.

  The electric blower of the present invention transfers heat generated in the stator winding and core to a plurality of guide blades extending in the air passage, forcibly cools with the air flow generated by the impeller, and reduces the dynamic pressure of the air flow. Can be converted to static pressure. In addition, by rotating the impeller with a brushless motor, the motor itself can reduce heat generation and can be driven with a large amount of electric power, thereby realizing a small-sized electric blower having high blowing performance.

Moreover, the vacuum cleaner using such an electric blower has a strong suction force, good dust removal, and a lightweight electric blower, so it is easy to use with a small turn.

The partial cross section figure of the electric blower in the 1st Embodiment of this invention Partial sectional perspective view of the electric blower Partial cross-sectional perspective view of the impeller of the electric blower Partial cross-sectional perspective view of the brushless motor of the electric blower Partial cross-sectional perspective view of the stator of the electric blower Sectional drawing showing the structure of the vacuum cleaner using the electric blower Partial sectional perspective view of the electric blower Partial sectional drawing of the electric blower in the 2nd Embodiment of this invention Partial sectional perspective view of the electric blower Partial cross-sectional perspective view of the brushless motor of the electric blower Partial cross-sectional perspective view of the stator of the electric blower Cross section of a conventional electric blower Cross section of a conventional electric blower Cross section of a conventional electric blower

  According to a first aspect of the present invention, there is provided a brushless motor including a rotor having a rotating shaft, a stator disposed on an outer periphery of the rotor, a frame that holds a bearing of the rotating shaft and covers the stator, and the rotating shaft. A motor case arranged by providing a fixed impeller and a space serving as a ventilation path between the outer peripheral surface of the stator, and a fan case that covers the impeller and is fixed to the motor case. The core and the winding are formed of a molded part made of resin, and are integrally molded with a plurality of guide vanes that protrude from the mold part and extend into the air passage. The electric blower forms a plurality of air passages in the air passage.

  As a result, the heat of the stator generated in the windings and the core is easily conducted to a plurality of guide blades integrally formed with the stator. When the impeller is driven to rotate by the brushless motor, the airflow generated by the impeller is smoothly guided by the plurality of guide vanes and the guide vanes are forcibly cooled, so that heat can be efficiently released to the outside of the motor. In addition, since the guide vanes act as a diffuser, it is possible to cool the brushless motor and convert the dynamic pressure of the airflow into a static pressure to realize a small electric blower having high air blowing performance.

  In the second aspect of the invention, in particular, the impeller of the first aspect of the invention has a mixed flow type blade that causes the airflow flowing in from the inlet to flow out at an intermediate angle between the axial direction and the radial direction. As compared with the above, the outer diameter can be reduced, and it is not necessary to provide a curved portion in the air passage of the diffuser, so that an air passage with less pressure loss can be configured.

  In the third aspect of the invention, in particular, since the mold part of the first or second aspect of the invention is molded from a resin having high thermal conductivity, heat generated in the stator winding and core is conducted to a plurality of guide vanes. Since the heat inside the brushless motor can be efficiently released to the outside, the cooling effect of the brushless motor can be improved.

  In the fourth aspect of the invention, in particular, since the resin of the mold part of the third aspect of the invention is filled with a filler, a heat conduction path serving as a heat path is formed inside the resin, and the heat conductivity of the resin is increased. It can be easily increased.

In the fifth invention, in particular, the plurality of guide vanes of any one of the first to fourth inventions form an independent passage in the air passage by abutting against the inner wall of the motor case, and from the upstream to the downstream of the air passage. Since the sectional area of the independent passage is gradually increased, the heat dissipation area of the guide vanes can be expanded to improve the cooling effect of the motor, and the airflow from the impeller can be guided smoothly, Since dynamic pressure can be converted into static pressure, an electric blower having a small size and high blowing performance can be realized.

  In the sixth aspect of the invention, in particular, since the plurality of guide vanes of any one of the first to fifth aspects are formed in a spiral shape on the outer periphery of the stator, the length of the air passage on the meridian surface is limited. However, it is possible to increase the length of the independent passage and increase the heat radiation area by making it spiral, and the cooling effect of the motor can be improved. Moreover, since the independent passage which can be used as a diffuser also becomes long, while improving ventilation performance, the sound insulation effect with respect to the noise which propagates air through a ventilation path is improved, and a small and low-noise electric blower can be realized.

  In the seventh invention, in particular, since the plurality of guide vanes of any one of the first to sixth inventions are continuously reduced in thickness from the upstream side to the downstream side of the air passage, the outer shape of the motor case is changed. In addition, since the sectional area of the independent passage can be continuously increased, a small diffuser that also serves to cool the motor can be easily configured.

  In the eighth invention, in particular, the outer shape of the motor case according to any one of the first to seventh inventions is continuously increased from the upstream to the downstream of the air flow, and the sectional area of the air passage is gradually increased. The air passage between the stator outer peripheral surface and the motor case can be continuously increased in the meridian plane, and the cross-sectional area of the air passage can be easily adjusted according to the outer shape of the motor case. Since adjustment is also possible, the cooling configuration required for the motor can be easily realized.

  The ninth aspect of the invention is particularly a vacuum cleaner equipped with any one of the electric blowers of the first to eighth aspects, so that it has a strong suction force, good dust removal, and a small body size. It becomes a vacuum cleaner that is easy to use and convenient.

  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 showing a configuration of an electric blower according to Embodiment 1 of the present invention, FIG. 2 is a partial cross-sectional perspective view of the electric blower, and FIG. 3 is an impeller used for the electric blower. FIG. 4 is a partial sectional perspective view of a brushless motor used in the electric blower, and FIG. 5 is a partial sectional perspective view of a stator used in the electric blower.

  As shown in FIGS. 1 to 3, the electric blower 1 a includes a rotor 3 having a rotating shaft 2 and composed of a permanent magnet, a stator 4 a disposed on the outer periphery of the rotor 3, and a bearing 5 of the rotating shaft 2. A brushless motor 7a composed of a frame 6 for holding the front and rear surfaces of the stator 4a, an impeller 8 having six mixed flow blades 8a formed by a three-dimensional curved surface fixed to the rotary shaft 2, and a stator The motor case 10a is provided with a space to be a ventilation path 9 between the outer peripheral surface of 4a and the fan case 11 that covers the impeller 8 and is fixed to the upstream side of the ventilation path 9 of the motor case 10a. . The stator 4a is composed of a mold part 13a in which a core 12a and a winding wound around the core 12a are molded with resin.

As shown in FIG. 5, the stator 4a is formed with a plurality of guide vanes 14a protruding from the mold portion 13a and extending into the air passage 9, and the longitudinal directions of the plurality of guide vanes 14a are inclined from the axial direction. A plurality of independent passages 15 are formed in the air passage 9 by contacting the inner wall of the motor case 10a, and the rotating shaft 2 extends from the upstream to the downstream of the air passage 9. It has a spiral shape centered around.

  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, and accordingly, the cross-sectional area of the independent passage 15 is continuously increased. In addition, the resin 13a of the mold part was filled with a filler in Poniphenylene Sulfide (PPS) to improve thermal conductivity, and the stator 4a was manufactured by injection molding. The core 12a and the outer peripheral surface of the mold part have substantially the same surface, and the frame 6 that covers the front and rear surfaces of the mold part holds the stator 4a on the outer peripheral surface of the stator 4a via the three columns 6a. The inlet tip of the impeller 8 and the suction port 11a of the fan case 11 are sealed via a PTFE resin ring 16 in a state where the impeller 8 is rotatable.

  About the electric blower 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. 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 and rearward in the impeller 8, and the inside of the impeller 8 becomes negative pressure, and the inside of the impeller 8 from the front of the suction port 11 a of the fan case 11. An airflow A flowing into the air is generated. The air flow A flows in the axial direction from the inlet tip of the impeller 8, flows along the six diagonal flow blades, and then flows out of the impeller 8 at an intermediate angle between the axial direction and the radial direction.

  The airflow flowing out from the impeller 8 flows into the plurality of independent passages 15 formed by the guide blades 14a, flows through the independent passages 15 along the outer peripheral surface of the stator 4a, and flows out to the outer periphery of the electric blower 1a. Since the sectional area of the independent passage 15 gradually increases from upstream to downstream, the dynamic pressure is converted to static pressure while the airflow is decelerated. The blowing performance of the electric blower 1a is expressed as a ratio between the electric power input to drive the electric blower 1a and the amount of work performed by the electric blower 1a (the product of the degree of vacuum generated by the rotation of the impeller 8 and the flow rate). 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 be at an intermediate angle between the axial direction and the radial direction, the outer diameter can be made smaller than that of the centrifugal type impeller 8. Further, the air path on the diffuser side can be configured as a straight air path with little pressure loss, and it is not necessary to provide a curved portion in the air path, so that an air path with less pressure loss can be configured.

  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, the amount of heat generated is smaller than that of an AC commutator motor. Heat generation of the stator 4a is generated in both the winding and the core 12a, and Joule heat generated by the current flowing through the winding is conducted to the plurality of guide blades 14a integrally formed by conducting heat through the mold portion 13a.

  On the other hand, eddy currents are generated due to changes in the magnetic flux density of the core 12a due to changes in the magnetic field and magnetic flux fluctuations passing through the core 12a, and heat is generated in the core 12a. When the gas flows along the outer peripheral surface, heat is transmitted from the guide blade 14a and the outer peripheral surface of the stator 4a to the air flow. As a result, the heat generated in the stator 4a is transported to the outside of the electric blower 1a. Cools well.

  That is, the guide vane 14a combines the function of a diffuser that performs pressure recovery and a function as a heat radiating fin. By adopting this configuration, not only the heat radiation efficiency is improved, but also the rotational movement is driven by the brushless motor 7a. The electric blower 1a can be reduced in size by reducing the amount of heat generated by itself.

  Further, since the guide vane 14a is formed in a spiral shape around the rotating shaft 2 on the outer periphery of the stator 4a, the length of the independent passage 15 is increased even in the limited length of the air passage 9 on the meridian surface. The heat dissipation area can be expanded. Moreover, by integrally molding the mold portion 13a and the guide vanes 14a constituting the stator 4a, the heat generated from the stator 4a can be efficiently radiated, and the cooling effect of the electric blower 1a can be greatly improved. Furthermore, since the independent passage 15 that can be used as a diffuser is also long, the air blowing performance is improved and the sound insulation effect is improved against the noise propagating through the air passage 9 to realize a small and low noise electric blower 1a. Can do.

  In particular, the rotational noise of the electric blower 1a, which is a problem as annoying noise, is caused by a frequency determined by the product of the number of blades and the rotational speed of the impeller 8 and a harmonic including its overtone, and has a high frequency even in an audible frequency range. The spiral guide blade 14a also functions as a sound insulation wall because it is a local noise and has a straight traveling property when the noise propagates. Further, if the sound absorbing materials 25a and 25b having the sound absorbing frequency range matched with the rotational noise frequency range are arranged in the cleaner body 22, the noise reduction effect can be further enhanced.

  It is desirable to use a resin 13a having a high thermal conductivity for the mold part 13a, and the Joule heat generated in the winding easily conducts heat to the plurality of guide blades 14a through the mold part 13a having improved thermal conductivity. The airflow generated by the impeller 8 can be efficiently cooled. The resin of the mold part 13a may be filled with a filler such as powder or fiber having high thermal conductivity to improve thermal conductivity. Specifically, polyphenylene sunfide resin 13a (PPS), nylon, liquid crystal A polymer (LCP) or the like may be filled.

  As the conductive filler, metal powder, graphite, carbon black or the like can be used, and as the insulating filler, sintered ceramics such as aluminum nitride, boron nitride or alumina can be used. The filler may be used properly according to the necessity of insulation of each part. In the present embodiment, since the mold part around the windings needs to be insulated, the guide blade 14a is made of an insulating filler. Including injection molding.

  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. Therefore, a method may be employed in which the winding peripheral part and the guide vane 14a are separately formed from a resin blended with an insulating filler and a conductive filler, 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. FIG. 6 is a cross-sectional view showing the configuration of the electric vacuum cleaner.

  As shown in FIG. 6, the vacuum cleaner 17 includes a vacuum cleaner main body 22 having a dust collection chamber 19 communicating with the main body intake port 18 and a blower chamber 21 having a main body exhaust port 20, and a main body in the dust collection chamber 19. A dust collection bag 23 that is airtightly attached to the air inlet 18, an electric blower 1 a installed in the blower chamber 21, a soundproof cover 24 made of flame-retardant resin that covers the electric blower 1 a, and an upper and lower portions of the blower chamber 21. Sound absorbing material 25a, 25b. 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 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 filtered and separated by the dust bag 23 flows into the impeller 8 of the electric blower 1a, passes through the air guide formed by the plurality of guide blades 14a, and then flows out from the body exhaust port 20 of the soundproof cover. Then, it is discharged to the outside of the cleaner body 22.

  The electric blower 1a mounted on the vacuum cleaner 17 has good heat dissipation as described above, and the impeller 8 is driven to rotate by the brushless motor 7a, thereby reducing the heat generated by the motor itself and driving at high power for high speed. Rotation is possible, a strong suction force can be provided, and a small size and high air blowing performance can be provided.

  Therefore, the electric vacuum cleaner 17 is equipped with a small electric blower 1a having high air blowing performance, so that dust removal is good due to a strong suction force, and the small electric blower 1a is light in weight, so it has a small turn and is easy to use. Good.

  Further, as shown in FIG. 6, by mounting a small electric blower 1 a in the cleaner body 22, the space in which the sound absorbing materials 25 a and 25 b can be arranged is expanded, and the sound absorbing material provided in the cleaner body 22. By increasing the installation area of 25a, 25b, the sound absorption effect can be expanded and the operation sound of the vacuum cleaner 17 can be reduced. Further, if the sound absorbing materials 25a and 25b having the sound absorbing frequency range matched with the rotational noise frequency range are arranged in the cleaner body 22, the noise reduction effect can be further enhanced. Furthermore, the use of a resonance type silencing structure that exhibits a significant silencing effect on the sound of a specific frequency in combination with the sound absorbing materials 25a and 25b can greatly improve the silencing effect on rotational noise.

  As described above, in the present embodiment, the stator 4a is formed by molding the core 12a and the winding with the resin 13a having high thermal conductivity, and the stator 4a is integrally molded from the resin 13a portion with the air passage. 9 is formed on the outer periphery of the stator 4a so that the longitudinal direction is the axial direction, and is brought into contact with the inner wall of the motor case 10a. By forming the plurality of independent passages 15 in the air passage 9, the airflow generated from the impeller 8 is smoothly guided to the independent passage 15 and the heat generated in the windings and the core 12a is transferred to the plurality of guide blades 14a. The heat can be transferred from the outer peripheral surfaces of the guide vanes 14a and the stator 4a to the air flow and released to the outside of the electric blower 1a, and the brushless motor 7a can be efficiently used. Possible retirement.

  Further, since the plurality of independent passages 15 formed in the air passage 9 also has a function of a diffuser, the air pressure is restored to static pressure, and the guide blade 14a serves as a sound insulation wall against the rotational noise generated by the impeller 8. Since it functions, low noise and air blowing performance can be improved.

  In the present embodiment, a case has been described in which the independent passage 15 is formed by contacting a plurality of guide vanes 14a with the inner wall of the motor case 10a. However, the guide vanes 14a and the inner wall of the motor case 10a are bonded to each other without any gap. It is desirable to configure, and the flow between the independent passages 15 can be suppressed and the airflow can flow smoothly.

  Further, in the present embodiment, the case has been described in which the outer shape of the motor case 10a is expanded at a predetermined angle from the upstream side to the downstream side of the air passage 9 to gradually increase the cross-sectional area of the independent passage 15. However, the motor case 10a has a spiral shape. The twisting pitch in the axial direction of the guide vanes 14a may be gradually increased toward the downstream, and the same effect can be obtained by increasing the cross-sectional area of the independent passage 15.

  In the present 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, the fan case and the motor case are integrated. The outer periphery of the brushless motor may be covered with the outer case 26 using the outer case 26 that has been molded, and the same effect can be obtained.

(Embodiment 2)
8-11 shows the structure of the electric blower in Embodiment 2 of this invention. 8 is a partial sectional view of the electric blower, FIG. 9 is a partial sectional perspective view of the electric blower, and FIG. 10 is a partial sectional perspective view of a brushless motor used in the electric blower. FIG. 3 is a partial cross-sectional perspective view of a stator used in the electric blower. About the same element as Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  8 to 10, the electric blower 1 b includes a stator 4 b configured by a molded portion 13 b in which a core 12 b and a winding are molded with a resin, and a motor case 10 b having substantially the same diameter from upstream to downstream of the air passage 9. And the air passage 9 between the outer peripheral surface of the stator 4b and the motor case 10b, and a plurality of plate-shaped guide vanes 14b and the mold portion 13b that protrude from the mold portion 13b and extend to the air passage 9 are integrally molded. The plurality of guide vanes 14b are arranged on the outer periphery of the stator 4b so that the longitudinal direction is inclined with respect to the axial direction, and a plurality of independent passages are formed in the air passage 9 by contacting the inner wall of the motor case 10b. 15 is formed.

  As shown in FIGS. 9 and 10, the guide vanes 14 b are continuously reduced in thickness from the upstream side to the downstream side of the air passage 9, and the length of the guide vanes 14 b disposed on the outer periphery of the stator 4 b is alternated. The sectional area of the independent passage 15 is gradually increased by shortening the distance. 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 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 windings, 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, the impeller 8 becomes negative pressure, and an airflow A flowing into the impeller 8 from the front is generated. . The airflow A flows in the axial direction from the inlet of the impeller 8, flows along the six mixed flow blades, and then flows out of the impeller 8 at an intermediate angle between the axial direction and the radial direction.

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

  Heat generation of the stator 4b occurs in both the windings and the core 12b, and 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, from the outer peripheral surfaces of the guide vanes 14b and the stator 4b. Heat is transferred to the airflow, and 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, the guide vane 14b functions as a diffuser that performs pressure recovery and a function as a heat radiating fin. With this configuration, the electric blower 1b can be downsized.

  In the present embodiment, since the guide blade 14b has a plate shape, molding is easier than the guide blade 14b having a curved surface like a spiral, and the molded product is removed from the mold during injection molding. The number of wings that can be increased can be increased. In addition, it is possible to increase the heat radiation area of the guide vanes 14b functioning as heat radiation fins, and it is possible to reduce the cost by simplifying the configuration of the mold. In addition, since the core 12b has only a plurality of straight grooves, the core 12b can be manufactured by laminating the pressed electromagnetic steel sheets, so that it is not necessary to have a complicated divided structure and is easy to manufacture.

  The thickness of the guide blades 14b and the number of blades are such that the cross-sectional area required for the diffuser and the rate of change of the cross-sectional area with respect to the plurality of independent passages 15 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 present embodiment, the airflow generated from the impeller 8 is smoothly guided to the independent passage 15, and the heat generated in the winding and the core 12b is conducted to the plurality of guide blades 14b. The heat can be transferred from the outer peripheral surfaces of the guide vanes 14b and the stator 4b to the air flow and released to the outside of the electric blower 1b, the brushless motor 7b can be efficiently cooled, and the guide vanes 14b are plate-shaped. Therefore, the mold configuration can be simplified, and the cooling performance can be improved by increasing the number of blades.

  Note that the configurations of the first and second embodiments described above are not limited to this, and can be appropriately combined as necessary.

  As described above, the electric blower according to the present invention improves heat dissipation from the stator, enables driving with large electric power, and can obtain a small and high blowing performance. It can be applied to the vacuum cleaner.

DESCRIPTION OF SYMBOLS 1a, 1b Electric blower 2 Rotating shaft 3 Rotor 4a, 1b Stator 5 Bearing 6 Frame 7a, 7b Brushless motor 8 Impeller 9 Air passage 10a, 10b Motor case 11 Fan case 12a, 12b Core 13a, 13b Mold part 14a, 14b Guide blade 15a, 15b Independent passage 17 Vacuum cleaner

Claims (9)

A rotor having a rotating shaft; a stator disposed on an outer periphery of the rotor; a motor configured to hold a bearing of the rotating shaft and covering the stator; an impeller fixed to the rotating shaft; A motor case disposed with a space serving as an air passage between the stator and an outer peripheral surface; and a fan case that covers the impeller and is fixed to the motor case. And a plurality of guide vanes that protrude from the mold portion and extend into the air passage, and the plurality of guide vanes are formed in the air passage. Electric blower that forms the road. 2. The electric blower according to claim 1, wherein the impeller has a mixed flow type blade that causes the airflow flowing in from the inlet to flow out at an intermediate angle between the axial direction and the radial direction. The electric blower according to claim 1 or 2, wherein the mold part is formed of a resin having high thermal conductivity. The electric blower according to claim 3, wherein the resin of the mold part is filled with a filler. The plurality of guide blades are in contact with the inner wall of the motor case to form an independent passage in the air passage, and the sectional area of the independent passage is gradually increased from the upstream to the downstream of the air passage. The electric blower described in the item. The electric blower according to any one of claims 1 to 5, wherein the plurality of guide vanes are formed in a spiral shape on the outer periphery of the stator. The electric blower according to any one of claims 1 to 6, wherein the plurality of guide vanes gradually increase the cross-sectional area of the air passage by reducing the thickness continuously from the upstream to the downstream of the air passage. The electric blower according to any one of claims 1 to 7, wherein the outer diameter of the motor case is continuously increased from the upstream to the downstream of the airflow to gradually increase the cross-sectional area of the air passage. The vacuum cleaner carrying the electric blower of any one of Claims 1-8.

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