JP2013029033A - Electric blower - Google Patents

Abstract

An electric blower that improves the strength of a front shroud, prevents the front shroud from being peeled off from a blade by centrifugal force during high-speed rotation, and has high blowing performance.
An impeller is rotatably driven by an electric motor. The impeller includes a front shroud having an air inlet, a rear shroud arranged to face the front shroud, a front shroud, and a rear shroud. A plurality of blades 26 sandwiched between the front and rear shrouds 23, each having a concave groove portion 38 projecting from the inner surface side of the front shroud 23. The concave groove portion 38 has the same bending direction as the blades 26, and is formed between each of the plurality of blades 26. By providing the flow path in the vicinity of the inner wall surface 37 of the front shroud 23 of the front shroud 23 so as to be divided substantially evenly, the strength improvement of the impeller front shroud is realized with a light weight and low pressure loss configuration, and an electric blower having high blowing performance It can be.
[Selection] Figure 4

Description

  The present invention relates to an electric blower that improves the strength of an impeller by providing a concave groove in a front shroud and improves the reliability of the impeller with a simple configuration.

  Conventionally, this type of electric blower has been widely used in household vacuum cleaners. Recent vacuum cleaners are required to have a strong suction force, and in order to obtain a stronger suction force, it is necessary to improve the blowing performance of the electric blower of the vacuum cleaner. In order to improve the blowing performance, it is desired to increase the fan output as well as the fan efficiency. In order to increase the fan output, it is essential to increase the rotation speed of the fan. As the rotation speed increases, the load on the impeller increases in proportion to the weight and radius, and increases in proportion to the square of the angular velocity. Improvement is also an essential technology. Therefore, in order to increase the strength of the impeller, the following techniques have been developed conventionally.

  For example, to improve the strength of the impeller, there is a configuration in which warpage of the rear surface shroud is prevented by providing a plurality of linear ribs from the center of the rear surface shroud of the impeller toward the outer periphery (see, for example, Patent Document 1).

10 to 11, FIG. 10 is a partial cross-sectional view of a conventional electric blower described in Patent Document 1, and FIG. 11 is a plan view of a rear shroud of an impeller of the electric blower.
In FIG. 10, this type of conventional electric blower 1 includes an electric motor 2, an impeller 4 having a plurality of blades 3, and an electric motor 2 having an impeller 4 fixed to the shaft end of a rotating shaft 5. An electric blower 1 for an electric vacuum cleaner in which air sucked from the upper center blows out from an outer peripheral portion 6 of an impeller 4 is disclosed. FIG. 11 is a view showing a configuration in which warpage of the rear shroud 7 is suppressed by providing a plurality of straight ribs 8 from the center of the rear shroud 7 to the outer periphery of the impeller 4. When the impeller 4 rotates at high speed, FIG. The vibration in the thrust direction can be suppressed and low vibration and low noise can be realized.

JP-A-7-189993

  However, the configuration of the conventional electric blower described in Patent Document 1 cannot improve the strength of the front shroud of the impeller, and cannot prevent the front shroud from being deformed in the thrust direction by centrifugal force during high-speed rotation. Further, since the rib 8 is provided at a position crossing the rear surface shroud 7 and the blade 3, air leaks through the gap of the rib 8 between the blade 3 and the rear surface shroud 7. Further, the rib 8 is present on the inner surface side through which the air of the rear surface shroud 7 passes so as to prevent the air flow and increase the pressure loss.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an electric blower that realizes improvement in strength of an impeller front shroud with a light weight and low pressure loss configuration and has high blowing performance.

In order to solve the above-described conventional problems, an electric blower of the present invention includes an electric motor having a rotating shaft and an impeller that is rotationally driven by the electric motor, and the impeller is opposed to the front shroud having an intake port and the front shroud. A rear shroud disposed on the front shroud and a plurality of blades sandwiched between the front shroud and the rear shroud, the inner surface of the front shroud is provided with a protruding concave groove, and the concave groove is the same as the bending direction of the blade, The flow path in the vicinity of the inner wall surface of the front shroud between each of the plurality of blades is arranged so as to be substantially evenly divided.

  As a result, when the electric motor is driven, force is applied to the front shroud of the impeller in the radial direction and the axial direction by the centrifugal force generated by the rotational force, but deformation is increased by increasing the strength by the recessed groove portion added to the front shroud. Can be suppressed. In addition, the shape of the added concave groove is the same as the bending direction of the blade, and the flow path in the vicinity of the inner wall surface of the front shroud between each of the plurality of blades is provided so as to be divided approximately evenly. Air leakage does not occur from the gaps in the front shroud, and the concave groove can also serve as the sub wing, enabling air to be blown out efficiently, and realizing an electric blower that is lightweight and has high blowing performance. it can.

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

  The electric blower of the present invention is provided with a protruding groove portion on the inner surface side of the front shroud, the groove portion being the same as the bending direction of the blade, and a flow path near the inner wall surface of the front shroud between each of the plurality of blades. Are arranged so as to be divided substantially evenly, thereby improving the strength of the impeller front surface shroud and suppressing deformation. In addition, air leakage does not occur from the gap between the blade and the front shroud, and the concave groove portion can also serve as a sub wing, so that air can be blown out efficiently.

The longitudinal cross-sectional view of the electric blower in the 1st Embodiment of this invention The perspective view which showed the components structure of the electric blower The longitudinal cross-sectional view which showed the structure of the electric vacuum cleaner using an electric blower Top view of front shroud of impeller of electric blower Partially enlarged sectional view of the impeller of the electric blower The top view of the front shroud of the impeller of the electric blower in the 2nd Embodiment of this invention Partially enlarged sectional view of the impeller of the electric blower The top view of the front shroud of the impeller of the electric blower in the 3rd Embodiment of this invention Partially enlarged sectional view of the impeller of the electric blower Partial longitudinal sectional view of a conventional electric blower Plan view of rear shroud of impeller of conventional electric blower

  1st invention is equipped with the electric motor which has a rotating shaft, the impeller which is rotationally driven by an electric motor, and the impeller is a front surface shroud which has an inlet, the rear surface shroud arranged so as to oppose the front surface shroud, and the front surface shroud, The front shroud is composed of a plurality of blades sandwiched by the rear shroud. The front shroud is provided with a protruding groove portion on the inner surface side, the groove portion being the same as the bending direction of the blade, and the front shroud between each of the blades. This is an electric blower configured to be arranged so as to divide the flow path in the vicinity of the inner wall surface substantially evenly.

  As a result, the impeller is rotated by driving the electric motor, air flows into the impeller, and the airflow passes through the plurality of blades, the front shroud, and the rear shroud and protrudes toward the inner surface of the front shroud. By providing the groove, the strength of the front shroud can be improved and the deformation of the front shroud can be suppressed, and the concave groove can exert a secondary wing action and efficiently send out the air flow in the centrifugal direction to achieve a small and high air flow. An electric blower having performance can be realized.

  In particular, since the second invention is provided with a plurality of concave grooves existing between the blades of the impeller of the first invention, the strength of the front shroud can be further improved, and deformation of the front shroud can be suppressed. An electric blower having a small size and high air blowing performance can be realized by the concave groove portion exhibiting the auxiliary blade action and efficiently sending the air flow in the centrifugal direction.

  In the third aspect of the present invention, since a plurality of concave grooves existing between the blades of the impeller of the first or second aspect are provided in a staggered manner, the strength of the front shroud is further improved, and deformation of the front shroud is suppressed. In addition, since the concave groove portion exerts the auxiliary blade action and efficiently sends the air flow in the centrifugal direction, a small electric blower having high air blowing performance can be realized.

  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)
FIGS. 1-5 shows the structure of the electric blower in Embodiment 1 of this invention. FIG. 1 is a central longitudinal sectional view of the electric blower, FIG. 2 is a perspective view showing a component configuration of the electric blower, and FIG. 3 is a vertical cross section showing a configuration of a vacuum cleaner using the electric blower. FIG. 4 is a plan view of a front shroud of the impeller of the electric blower, and FIG. 5 is a partially enlarged sectional view of the impeller of the electric blower.

As shown in FIGS. 1 to 5, the electric blower 11 a includes a rotor 13 having a rotation shaft 12, a stator 14 disposed opposite to the outer periphery of the rotor 13, a bearing 15 of the rotation shaft 12, and a motor frame 16 that covers the stator 14. The impeller 18 fixed to the rotary shaft 12, the air guide 19 that forms a ventilation path on the outer periphery of the impeller 18, and the fan case that covers the impeller 18 and is fixed to the front surface of the air guide 19. 20.
The air guide 19 has a plurality of guide vanes 21 and is fixed in a state where the fan case 20 is in contact with the upper surface thereof, and an independent air passage 22 is formed between the guide vanes 21, so The air passage 22 has a channel cross-sectional area that continuously increases from the outer periphery of the impeller 18 to the outer periphery of the air guide 19. Further, the impeller 18 is configured by sandwiching an inducer 25 having a three-dimensional wing and a plurality of blades 26 by a front shroud 23 made of sheet metal and a rear shroud 24 facing the front shroud 24.

  In FIG. 3, the vacuum cleaner 27 includes a vacuum cleaner main body 32 having a dust collection chamber 29 communicating with the main body intake port 28 and a blower chamber 31 having a main body exhaust port 30, and a main body intake port 28 in the dust collection chamber 29. A dust bag 33 that is airtightly installed, an electric blower 11 a installed in the blower chamber 31, a soundproof cover 34 made of a flame-retardant resin that covers the electric blower 11 a, and a sound absorbing material arranged above and below the blower chamber 31. 35. Although not shown, a hose and an extension pipe are sequentially connected to the main body inlet 28, and a nozzle for sucking dust on the floor surface is attached to the tip of the extension pipe.

  About the electric blower comprised as mentioned above and the vacuum cleaner 27 using the same, the operation | movement and an effect | action are demonstrated below.

  First, the operation of the electric blower 11a will be described. In FIG. 1, a rotating magnetic field is generated by energizing and exciting the windings of the electric motor 11 b, the rotor 13 rotates in synchronization with the rotating magnetic field, and the impeller 18 fixed to the rotating shaft 12 rotates. Due to the centrifugal force generated by the rotation of the impeller 18, the air inside the impeller 18 is pushed outward and rearward inside the impeller 18, and the inside of the impeller 18 becomes negative pressure, and an airflow flowing into the impeller 18 from the front is generated. The airflow flows axially from the air inlet 39 of the impeller 18 and flows along a plurality of internal flow paths formed by the inducer 25, the plurality of blades 26, the front shroud 23, and the rear shroud 24, and then the impeller 18. It flows out to the outer periphery. The airflow that has flowed out of the impeller 18 flows into the independent air passages 22 formed by the plurality of guide vanes 21 in the air guide 19 and flows toward the outer periphery of the air guide 19. At that time, since the cross-sectional area of each independent air passage 22 increases from the outer periphery of the impeller 18 to the outer periphery of the air guide 19, the dynamic pressure is converted into static pressure while the flow velocity of the airflow flowing through the independent air passage 22 is reduced. Is done. If there is a gap between the blade 26 and the front shroud 23 or the rear shroud 24, air may leak from the gap and cause a loss.

  The blower performance of the electric blower 11a is determined by the electric power input to rotationally drive the impeller 18 and the work performed by the electric blower 11a (the air output determined by the product of the degree of vacuum and the flow rate generated by the rotation of the impeller 18). It is expressed as a ratio. For this reason, increasing the degree of vacuum (static pressure) generated by the electric blower 11a at the actual flow rate is very important for improving the blowing performance of the electric blower 11a. In order to reduce the size of the electric blower 11a, it is necessary to rotate the impeller 18 at a high speed to reduce the diameter. The conventional electric blower 11a is driven at less than 50,000 rpm, and high speed rotation of 50,000 rpm or more is necessary for further miniaturization. In addition, when rotating at a high speed of 50,000 rpm or higher, the centrifugal force applied to the impeller 18 is proportional to the weight and radius and increases in proportion to the square of the angular velocity. Durability may reduce durability.

  Next, the operation of the electric vacuum cleaner 27 will be described. In FIG. 5, when the electric blower 11 a is started, the rotor 13 of the electric motor 11 b rotates, and the rotating shaft 12 rotates accordingly, and the impeller 18 attached to the rotating shaft 12 rotates. When the impeller 18 rotates, the dust collection chamber 29 is in a negative pressure state, and an air flow including dust sucked from a nozzle (not shown) passes through the main intake port and flows into the dust collection chamber 29. The clean airflow filtered and separated by the dust collection bag 33 flows into the impeller 18 of the electric blower 11a, passes through a plurality of air passages provided in the air passage, and then flows out from the exhaust port 30 of the soundproof cover 35. And released to the outside of the cleaner body 27.

  Since the electric vacuum cleaner 27 is equipped with the electric blower 11a which is small and has high air blowing performance, it has a strong suction force, good dust removal, the body size of the electric blower 11a is small, and a small turn makes it easy to use. Is good. Moreover, it is also possible to make the electric vacuum cleaner 27 with a low driving sound by extending the sound absorption area in the vacuum cleaner body 27 and the exhaust passage.

  As shown in FIG. 5, which is a cross-sectional view of a portion of the impeller 18 shown in FIG. 4, a protruding groove 38 is provided on the inner surface side of the front shroud 23. It is the same as the bending direction, and the flow paths in the vicinity of the inner wall surface 37 of the front shroud 23 between each of the plurality of blades 26 are arranged so as to be substantially evenly divided.

  As described above, in the present embodiment, the strength can be increased by providing the concave groove portion 38 in the front shroud 23 of the impeller 18. That is, when the impeller 18 is rotated at a high speed, the reliability can be secured, and a small and highly efficient electric blower 11a can be realized.

Furthermore, since the concave groove 38 is the same as the bending direction of the blade 26 and the flow path near the inner wall surface of the front shroud 23 between each of the plurality of blades 26 is arranged substantially equally, the blade 26. Since there is no gap between the front shroud 23 and the front shroud 23, there is no loss, and the channel groove in the vicinity of the inner wall surface 37 of the front shroud 23 exerts a secondary wing action to efficiently send airflow in the centrifugal direction. Thus, an electric blower having high blowing performance can be realized.

  In the present embodiment, the strength of the front shroud 23 is increased, so that the molding accuracy is improved and the vibration during rotation can be reduced, so that the effect of reducing the vibration of the impeller 18 can be obtained, and the vibration noise generated from the impeller 18 can be obtained. The noise of the entire electric blower can be reduced.

(Embodiment 2)
6 and 7 show the configuration of the electric blower according to Embodiment 2 of the present invention. 6 is a plan view of the front shroud 23 of the impeller 18 of the electric blower, and FIG. 7 is a partial cross-sectional view of the impeller 18 of the electric blower 11a (partial cross section seen from the AA direction of the impeller 18 of FIG. 6). Figure).
In addition, the same code | symbol is provided about the thing of the same structure as Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIGS. 6 and 7, the difference from the configuration of the first embodiment is that a plurality of concave grooves 38 of the front shroud 23 of the impeller 18 are provided and formed.

  In this way, a plurality of concave grooves 38 can be formed in the front shroud 23 of the impeller 18 as in the first embodiment.

  Advantages compared with the first embodiment are that, in the case of this embodiment, the strength of the front shroud 23 is further improved and the projections of the plurality of concave groove portions 38 provided near the inner wall surface 37 of the front shroud 23 are provided. The blowing performance can be further improved by the auxiliary blade.

  For this reason, according to the present embodiment, the reliability performance can be improved and the blowing performance can be improved as compared with the case of the first embodiment.

  In the present embodiment, the strength of the front shroud 23 is increased, so that the molding accuracy is improved and the vibration during rotation can be reduced, so that the effect of reducing the vibration of the impeller 18 can be obtained, and the vibration noise generated from the impeller 18 can be obtained. And the turbulent flow noise is reduced, and the noise of the entire electric blower can be reduced.

(Embodiment 3)
8 and 9 show the configuration of the electric blower according to Embodiment 3 of the present invention. 8 is a plan view of the front shroud 23 of the impeller 18 of the electric blower, and FIG. 9 is a partial cross-sectional view of the impeller 18 of the electric blower 11a (partial cross section viewed from the AA direction of the impeller 18 of FIG. 8). Figure).
In addition, the same code | symbol is provided about the thing of the same structure as Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIGS. 8 and 9, the configuration of the first embodiment is different from that of the first embodiment in that a plurality of concave grooves 38 of the front shroud 23 of the impeller 18 are provided in a staggered manner.

  In this way, a plurality of concave grooves 38 can be formed in a staggered manner in the front shroud 23 of the impeller 18 as in the first embodiment.

  As an advantage compared with the first embodiment or the second embodiment, in the case of this embodiment, the strength of the front shroud 23 is further improved and a plurality of zigzags provided in the vicinity of the inner wall surface 37 of the front shroud 23. The air blowing performance can be improved by the auxiliary wing formed by the protrusion of the concave groove portion 38.

  For this reason, according to the present embodiment, the reliability performance can be improved and the blowing performance can be improved as compared with the case of the first embodiment.

  In the present embodiment, the strength of the front shroud 23 is increased, so that the molding accuracy is improved and the vibration during rotation can be reduced, so that the effect of reducing the vibration of the impeller 18 can be obtained, and the vibration noise generated from the impeller 18 can be obtained. And the turbulent flow noise is reduced, and the noise of the entire electric blower can be reduced.

  In addition, the structure of each Embodiment 1-3 mentioned above is not limited to this, It can comprise suitably combining as needed.

  As described above, the electric blower according to the present invention improves the strength of the front shroud, can suppress deformation of the front shroud, and can reduce vibration of the impeller by reducing vibration during rotation. In addition, since the concave groove portion exerts the auxiliary wing action and efficiently sends out the air flow in the centrifugal direction, it is possible to realize a small electric blower having high air blowing performance. Can be applied to vacuum cleaner.

DESCRIPTION OF SYMBOLS 11a Electric blower 11b Electric motor 12 Rotating shaft 13 Rotor 14 Stator 15 Bearing 16 Motor frame 17 Brushless motor 18 Impeller 19 Air guide 20 Fan case 23 Front shroud 24 Rear shroud 26 Blade 38 Concave groove part 37 Inner wall vicinity 39 Inlet port

Claims (3)

An electric motor having a rotating shaft, an impeller that is rotationally driven by the electric motor, and the impeller has a front shroud having an air inlet, a rear shroud disposed to face the front shroud, the front shroud, and the rear surface It is composed of a plurality of blades sandwiched by a shroud, and is provided with a protruding groove portion on the inner surface side of the front shroud, the groove portion being the same as the bending direction of the blade, and between each of the blades The electric blower arranged to divide the flow path in the vicinity of the inner wall surface of the front shroud in substantially evenly. The electric blower according to claim 1, wherein a plurality of concave grooves existing between blades of the impeller are provided. The electric blower according to any one of claims 1 to 2, wherein a plurality of concave grooves existing between blades of the impeller are provided in a staggered manner.