JPH04179899A - Electric blower - Google Patents

Abstract

PURPOSE:To decrease efficiency loss caused by secondary flow and improve air sending efficiency by arranging protrusively short blades curving at an angle of delay to the rotating direction of an impeller on the top face in the outer peripheral part of a front shroud of the impeller. CONSTITUTION:Plural number of short blades 32 curving at an angle of delay to the rotating direction of an impeller 25 are arranged protrusively on the top face in the outer peripheral part of a front shroud 33 of the impeller 25. When the impeller 25 rotates, air flow is discharged from a blow-off port 35 of the impeller. Though a part of the air flow discharged from the blow-off port 35 of the impeller tries to enter into an inlet port 37 of the impeller by passing through the space 36 between a casing 21 and the front shroud 33, it is pushed back in the direction of the blow-off port 35 by means of the short blades 32 curving at an angle of delay to the rotating direction of the impeller 25. Thereby, secondary flow flowing into the space 36 can be reduced so that an electric blower having a high air sending efficiency can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric blower used in a vacuum cleaner or the like, and more particularly to an electric blower with improved air blowing efficiency.

2. Prior Art The structure of a conventional electric blower of this type is shown in FIGS. 4 and 5.
It was as shown in the figure.

The configuration will be described below with reference to the drawings.

The casing 1 contains an impeller 2 and an air guide 3, and a motor 4 rotates the impeller 2 at high speed to obtain air volume and vacuum pressure. The impeller 2 is composed of a plurality of blades 6, and a front shroud 6 and a rear shroud 7 that sandwich the blades 6.

Problems to be Solved by the Invention In response to the recent trend toward higher output power in vacuum cleaners, impellers in electric blowers have also been driven to rotate at higher speeds. Along with this, the vacuum pressure from the outlet 9 of the impeller 2 is also increased, the pressure difference between the outlet 8 and the outlet 9 of the impeller 2 increases, and water is discharged from the outlet 9 of the impeller 2. A part of the airflow passes through the small gap 10 between the impeller 2 and the casing 1, and then flows back into the impeller 2 from the suction port 8 of the impeller 2, which is a large amount of so-called secondary flow, which has been a problem until now. It has become impossible to ignore the efficiency Ronu caused by this secondary flow.

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and to provide an electric blower that reduces efficiency loss due to secondary flow and improves air blowing efficiency.

Means for Solving the Problems In order to achieve the above object, the present invention has a short grade protruding from the upper surface of the outer periphery of the front surface of the impeller, which curves at a lagging angle with respect to the rotational direction of the impeller. .

Additionally, short blades are extended from the blades of the impeller.

Moreover, the short blades are inclined toward the direction of rotation of the impeller.

Function: Electric feed f! of the present invention! Aircraft A has the above-mentioned configuration, with blades protruding from the upper surface of the front shroud of the impeller that are curved at a lagging angle with respect to the rotational direction of the impeller, so that the upper surface of the front shroud of the impeller and the casing are closely connected. The secondary flow that attempts to flow through the gap to the impeller suction port can be pushed back by the short blades and flowed into the motor through the air guide passage.

In addition, by extending the short blade from the blade,
Impellers can be produced in the same way as before, without increasing the number of steps required to install short blades.

In addition, by tilting the short blades toward the rotational direction of the impeller, the secondary flow that attempts to rotate through the short blades and flow into the gap between the casing and the casing is suppressed by the short blades. Secondary flow can be reduced reliably.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4. 1 and 4 show the first embodiment, and as shown in FIG. 3, the casing 2d has an intake hole 22 at the center of the upper surface, and the opening at the lower end is connected to the motor 23.
motor frame, 24K air (a h 75: installed as shown).The centrifugal impeller 25 is
A front shroud 33, a rear shroud 34, and a plurality of blades 26 sandwiched between both shrouds 33 and 34.
An air guide 27 is disposed below the impeller 25. The casing 21 is the impeller 26 and the air guide? A diffuser 28 formed by a casing 21 and an air guide 27 is arranged so as to have a passage that expands toward the outer periphery, and is smoothly and independently connected to the end of the diffuser 28 to form a return passage. 2
9 is formed. The return 9 passage 29 is the intake hole 3 of the motor.
This guides the airflow to 0. Note that the motor 23 described above
is a commutator motor for driving, and the airflow flowing into the intake hole 30 cools the inside of the motor and flows through the exhaust hole 3.
1 is ejected.

As shown in FIG.
The impeller 25 is mounted on the upper surface of the outer periphery of the front shroud 33.
A plurality of short blades 32 are protruded and curved at a lag angle with respect to the rotation direction of the blade. It is desirable that the number of short blades 32 is the same as that of the blades 26, but the number is not limited to the same number.

In the above configuration, when the motor 23 rotates the impeller 26, airflow is discharged from the impeller outlet 36. A part of the airflow discharged from the impeller blowing port 35 tries to enter the impeller suction port 37 through the gap 36 between the casing 21 and the front shroud 33, but the airflow is curved at a lag angle with respect to the rotation direction of the impeller 26. The short blade 32 pushes it back toward the blowing hole 36. This makes it possible to reduce the secondary flow flowing through the gap ssK.

Next, a second embodiment of the present invention is shown in FIG.

As shown in FIG. 2H)K, the blade 26 is formed with caulking portions 26a on the top and bottom thereof, which are caulked to the front shroud 33 and the rear shroud 34, and a short blade 32 is integrally extended at the tip. ing. The front shroud 33 is provided with a caulking hole 33a and a short blade insertion hole 33b. Further, the rear shroud 34 is provided with a caulking hole 34a.

In the above configuration, the caulking portion 26a of the blade 26 is connected to the caulking holes 33a of both shrouds 33 and 34.

34a, the short blade 32 is inserted into the short blade insertion hole 33b of the front shroud 33a, and the caulking portion 26a is caulked, so that the impeller 25 is assembled as shown in FIG.

With this assembly, the impeller can be produced in the same manner as in the past without increasing the number of steps for attaching the short blades 32, and it is possible to reduce conuts and improve productivity.

Next, a third embodiment of the present invention is shown in FIG.

As shown in the figure, the short blades a2 are provided to be inclined toward the rotation direction of the impeller 25.

In the above configuration, as shown in the first embodiment, by arranging the short blades 32 on the upper surface of the front shroud 33, stones and secondary flow are significantly reduced.
There is an air current flowing into the gap 36. On the other hand, by tilting the short blades 32 in the direction of rotation of the impeller 26, the airflow that tries to go around the short blades 32 can be suppressed, and the secondary flow can be more reliably controlled. can be reduced.

Effects of the Invention As is clear from the above description, the present invention provides short blades that protrude from the upper surface of the front shroud of the impeller and are curved at a lagging angle with respect to the rotational direction of the impeller. Since the secondary flow is pushed back through the short blades and flows into the air guide passage, it is possible to provide an electric blower with a small amount of secondary flow and high air blowing efficiency.

In addition, by extending the short blades integrally from the blades, it is possible to produce impellers with high air blowing efficiency without increasing the number of processes, and it is possible to reduce conut and improve performance all at once.

In addition, by arranging the short blades at an angle in the direction of rotation of the impeller, it is possible to suppress the airflow that returns to the short blades, so it is possible to more reliably reduce the secondary flow. - An electric blower with high layer blowing efficiency can be provided.

[Brief explanation of drawings]

1 to 4 show an electric blower according to an embodiment of the present invention, FIG. 1 is a perspective view of the impeller of the first embodiment, and FIG. 2 is a side view of the main part of the impeller of the second embodiment. In the sectional views, p) is an exploded view, ←) is an assembled view, Fig. 3 is a perspective view of the main parts of the impeller of the third embodiment, Fig. 4 is a partially cutaway side view of the electric blower,
FIG. 5 is a side sectional view of a conventional impeller, and FIG. 6 is a perspective view of essential parts of a conventional electric blower. 21 River...Casing, 23...Song/Motor, 26.
... Impeller, 26, old... Blade, 27...
・Air guide, 32...Short blade, 33・
...Front shroud. Name of agent: Patent attorney Akira Okaji and two others 25-
Input compensation 26- Rate Fig. 1 Rotation'r3 direction 25--Impeller 26- Window Fig. 3 21 Casing 23 Motor 1--Casing 9--tIR setting 0 No. 50 1--Casing 4 - Motor Figure 6

Claims (3)

[Claims] (1) A motor; a casing that is attached to a motor frame of the motor and includes an impeller and an air guide; An electric blower with protruding short blades that curve at a delayed angle. (2) The electric blower according to claim 1, wherein the short blades extend from the blades of the impeller. (3) The electric blower according to claim 1, wherein the short blades are inclined toward the direction of rotation of the impeller.