JP3123288B2 - Electric blower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower used for a vacuum cleaner.

[0002]

2. Description of the Related Art In recent years, vacuum cleaners have been characterized by enhanced suction power and reduced operating noise.
The electric blowers used are also producing many new technologies related to efficiency and noise.

[0003] A conventional electric blower will be described below. In FIG. 5, a casing 1 includes an impeller 2 and an air guide 3 and is attached to a motor frame of a motor 4. The impeller 2 includes an umbrella-shaped front shroud 5, a flat rear shroud 6, and a plurality of blades 7, and is fastened to the motor 4.

The operation of the electric blower constructed as described above will be described below. First, the impeller 2 is rotated at a high speed by the motor 4 to obtain an air volume and a vacuum pressure. At this time, as shown by the arrow in the figure, the air flow passed through the air guide 3 from the inside of the impeller 2, passed through the inside of the motor 4, and flowed out.

The rotation of the impeller 2 generates a static pressure and a dynamic pressure as a flow velocity. When this air flow passes through the air guide 3, the dynamic pressure as the flow velocity is converted to a static pressure by deceleration, thereby increasing the vacuum pressure.

[0006]

However, in the above-described conventional configuration, the air flow is complicated inside the impeller 2 depending on the shape, the number of revolutions, the air flow, and the like, and is not always in a state of flowing smoothly. . Such a flow causes a large loss when the airflow passes through the inside of the impeller 2, which causes a reduction in the overall blowing efficiency.

SUMMARY OF THE INVENTION Accordingly, it is a first object of the present invention to obtain an electric blower having a high air-blowing efficiency in a small air volume range at a high speed rotation by using an umbrella-shaped front shroud.

A second object of the present invention is to obtain an electric blower having a high air-blowing efficiency in a large air volume range at a high rotation speed by using an umbrella-shaped front shroud.

A third object is to obtain an electric blower having a high air blowing efficiency in a small air volume region or a large air volume region at a low rotation speed by using a substantially flat front shroud.

[0010]

In order to achieve the first object, an electric blower according to the present invention has a front shroud constituting an impeller formed in an umbrella shape, and a rear shroud comprising:
The electric blower is formed so as to be convexly curved toward the front shroud side from the center toward the outer periphery, and is formed to be convexly curved toward the motor near the outlet.

According to another aspect of the present invention, there is provided an electric blower in which the front shroud constituting the impeller is formed in an umbrella shape, and the rear shroud is convex toward the motor from the center toward the outer periphery. The electric blower is formed so as to have a curved shape, and has a curved shape protruding toward the front shroud in the vicinity of the outlet.

In order to achieve the third object, the present invention is an electric blower in which the front shroud is formed in a substantially planar shape in the first or second means.

[0013]

According to the electric blower of the first means, the airflow is not forced to change direction rapidly near the inlet at the time of high rotation and small air volume due to the impeller structure, and the flow passage is restricted. As a result, the gas flows into the impeller without being disturbed by separation or the like. Since the flow path is wide at the outlet, the flow becomes slow and smooth, and the flow becomes highly efficient.

In the electric blower of the second means, due to its impeller structure, when the rotation is high and the air volume is large, the airflow is not forced to change direction rapidly near the inlet and the flow passage is wide. Because of this, it will slowly fill without disturbing and will flow into the impeller. At the outlet, since the flow path is narrowed, the flow becomes smooth without causing separation or the like, and the flow becomes highly efficient.

[0015] In the electric blower of the third means, the direction of the flow is changed substantially at a right angle in accordance with the front shroud near the inlet by the impeller configuration. Then, when the rotation speed is high and the flow rate is small, or when the rotation speed is low and the flow rate is large, the flow becomes smooth and the efficiency is high as in the first and second means.

[0016]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 8 denotes a casing provided with an intake hole 9 in the center, and a side opposite to the intake hole 9 has a motor frame of a motor 10 (here, an air guide 11).
It is attached so that there is no air leakage in the outer peripheral part. Reference numeral 12 denotes a centrifugal impeller. The casing 8 includes the air guide 11 and the impeller 12.

The impeller 12 has a front shroud 13
-Consists of a rear shroud 14 and a plurality of blades 17. The front shroud 13 is formed in an umbrella shape,
The rear shroud 14 is gradually curved toward the front shroud 13 from the center toward the outer periphery in the vicinity of the inlet 15, and is formed to be convexly curved toward the motor 10 in the vicinity of the outlet 16. Are formed so as to be retracted toward the motor 10 as compared with the central portion. Between the front shroud 13 and the rear shroud 14, a plurality of blades 17 having a shape along the cross-sectional shape are integrated.

Next, the operation of this embodiment will be described. In this embodiment, the motor 10 is rotated at a high speed. Therefore, each part of the impeller 12 is at a high speed. Here, the front shroud 13 is formed in an umbrella shape, and the rear shroud 14 is gradually curved toward the front shroud 13 from the center toward the outer periphery near the inlet 15, and conversely near the outlet 16. Side, and the outer end is formed to recede toward the motor 10 side compared to the center, so that the air flow is rapid near the inlet 15 at high rotation and small air flow. Flow into the impeller 12 without being disturbed due to separation or the like since the flow path is restricted. Since the flow path is wide near the outlet 16, the flow becomes smooth and smooth, and the fan becomes highly efficient.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to FIG. The components other than the impeller are the same as those of the first embodiment, and the description is omitted by sharing the reference numerals. The front shroud 19 constituting the centrifugal impeller 18 has an umbrella shape, and the rear shroud 20 is
In the vicinity of 5, the shape is convexly curved toward the motor 10 from the center toward the outer periphery, and in the vicinity of the outlet 16, the shape is curved so as to be convex toward the front shroud 19. It is formed so as to retreat toward the motor 10 as compared with the portion. Between the front shroud 19 and the rear shroud 20, a plurality of blades 21 having a shape along the cross-sectional shape are integrated.

Next, the operation of this embodiment will be described. In this embodiment, the motor is rotated at a high speed. Therefore, each part of the impeller 18 has a high speed. Here, the front shroud 19 has an umbrella shape, and the rear shroud 20 is formed to be convexly curved toward the motor 10 from the center toward the outer periphery in the vicinity of the inlet 15 and conversely in the vicinity of the outlet 16. Due to the shape curved toward the 19th side, the airflow is not forced to change direction rapidly near the inlet 15 at high rotation speed and large air flow, and the flow path is widened. As a result, the air is slowly filled without causing disturbance and flows into the impeller 18. And exit 16
In the vicinity, since the flow path is narrowed, the flow becomes smooth without causing separation or the like, and the fan becomes highly efficient.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to FIG. The components other than the impeller are the same as those of the first embodiment, and the description is omitted by sharing the reference numerals. The front shroud 23 constituting the centrifugal impeller 22 is formed in a substantially planar shape, and the rear shroud 24 is
As in the first embodiment, near the inlet 15, the shape is gradually curved toward the front shroud 23 from the center toward the outer periphery, and near the outlet 16, the shape is convexly curved toward the motor 10. The outer edge is motor 1 compared to the center.
It is formed to recede to the 0 side. A plurality of blades 25 are integrated between the front shroud 23 and the rear shroud 24.

Next, the operation of this embodiment will be described. In this embodiment, the motor is rotated at a low speed, so that each part of the impeller 22 is at a low speed. Here, the front shroud 23 is formed in a substantially planar shape,
Since the rear shroud 24 is gradually curved toward the front shroud 23 from the center toward the outer periphery in the vicinity of the entrance 15 and is formed to be convexly curved toward the motor 10 in the vicinity of the exit 16, At low rotation and small air flow, near the inlet 15, the air flow changes its flow direction at almost right angles according to the front shroud 23, and since the flow path is restricted, there is no turbulence due to separation or the like. It flows into the impeller 23. Since the flow path is wide near the outlet 16, the flow becomes smooth and smooth, and the fan becomes highly efficient.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to FIG. The components other than the impeller are the same as those of the first embodiment, and the description is omitted by sharing the reference numerals. The front shroud 27 forming the centrifugal impeller 26 is formed in a substantially planar shape, and the rear shroud 28 is provided near the inlet 15 so that the motor 10
The outlet 16 has a curved shape that is convex toward the front shroud 27 side, and the outer peripheral end is receded toward the motor 10 compared to the center. Has formed. Between the front shroud 27 and the rear shroud 28, a plurality of blades 29 having a shape along the cross-sectional shape are integrated.

Next, the operation of this embodiment will be described. In this embodiment, the motor is rotated at a low speed. Therefore, each part of the impeller 26 is at a low speed. Here, the front shroud 27 is formed in a substantially planar shape, and the rear shroud 28 is formed so as to protrude toward the motor 10 from the center toward the outer periphery in the vicinity of the inlet 15 and conversely in the vicinity of the outlet 16 in the front. Shroud 27
Since it has a shape that is curved convexly to the side, the airflow changes its flow direction at almost a right angle according to the front shroud 27 near the inlet 15 at a low rotation and a large airflow, and Since the space is wide, the space is filled slowly without causing disturbance and flows into the impeller 26. In the vicinity of the outlet 16, since the flow path is narrowed, the flow becomes smooth without causing separation or the like, and the fan becomes a highly efficient fan.

[0025]

As described above, in the electric blower according to the present invention, the front shroud forming the impeller is formed in an umbrella shape.
The rear shroud is convexly curved toward the front shroud from the center toward the outer periphery, and is convexly curved toward the motor near the outlet. At this time, in the vicinity of the inlet, the air flow does not be forced to change direction rapidly, and flows into the impeller without being disturbed by separation or the like because the flow path is restricted. Since the flow path is wide at the outlet, the flow becomes slow and smooth, and the flow can be made highly efficient.

Further, in the electric blower of the present invention, the front shroud constituting the impeller is formed in an umbrella shape, and the rear shroud is formed in a convex shape toward the motor side from the center toward the outer periphery, and the vicinity of the outlet is formed. On the other hand, in the reverse direction, the airflow is curved convexly to the front shroud side, so at high rotation and large air volume, near the inlet, the airflow is not forced to change direction rapidly, and the flow path is Since it is wide, it fills slowly without disturbing and flows into the impeller. At the outlet, since the flow path is narrowed, the flow becomes smooth without causing separation or the like, and the flow becomes highly efficient.

In any one of the above-mentioned inventions, the electric blower according to the present invention has the front shroud formed in a substantially planar shape, so that the flow of the air near the inlet is changed substantially at right angles to the front shroud. When the rotation speed is high and the flow rate is small, or when the rotation speed is low and the flow rate is large, the flow is smooth and the efficiency is high.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an electric blower according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of an electric blower according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of an electric blower according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a main part of an electric blower according to a fourth embodiment of the present invention.

FIG. 5 is a half sectional view of a conventional electric blower.

[Explanation of symbols]

 12, 18, 22, 26 Impeller 13, 19, 23, 27 Front shroud 14, 20, 24, 28 Rear shroud 15 Inlet 16 Outlet 17, 21, 25, 29 Blade

Claims (3)

(57) [Claims] 1. A motor, comprising: a motor; and a casing mounted on a motor frame of the motor and including an impeller and an air guide, wherein the impeller has a front shroud.
A rear shroud and a plurality of blades, the front shroud is formed in an umbrella shape, and the rear shroud is formed so as to protrude toward the front shroud from the center toward the outer periphery. An electric blower that is curved in a convex shape to the side. 2. A motor, comprising: a motor; and a casing mounted on a motor frame of the motor and enclosing an impeller and an air guide, wherein the impeller has a front shroud.
The rear shroud is formed in an umbrella shape, and the rear shroud is formed in a convex shape toward the motor side from the center toward the outer periphery. An electric blower curved to form a convex shape. 3. The electric blower according to claim 1, wherein the shape of the front shroud is changed from an umbrella shape to a substantially planar shape.