JP2809867B2 - Electric blower - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower used for a vacuum cleaner or the like, and more particularly, to an electric blower with improved blowing efficiency.

2. Description of the Related Art The configuration of a conventional electric blower of this type is as shown in FIGS. Hereinafter, the configuration will be described with reference to the drawings.

The casing 1 contains an impeller 2 and an air guide 3, and the motor 4 rotates the impeller 2 at high speed to obtain the air volume and the vacuum pressure. The impeller 2 includes a plurality of blades 5, a front shroud 6 sandwiching the blades 5, and a rear shroud 7.

Problems to be Solved by the Invention In response to the recent trend of increasing the output of vacuum cleaners, the rotation speed of impellers in electric blowers has further increased. Accordingly, the vacuum pressure from the outlet 9 of the impeller 2 is further increased, and the pressure difference between the outlet 8 and the outlet 9 of the impeller 2 increases, so that the airflow discharged from the outlet 9 of the impeller 2 increases. A part of the so-called secondary flow, which partially flows through the small gap 10 between the impeller 2 and the casing 1 and flows into the impeller 2 from the suction port 8 of the impeller 2 again, has become a problem which has not been a problem so far. Efficiency losses due to secondary flows can no longer be ignored.

An object of the present invention is to solve the above-mentioned problems, and to provide an electric blower in which the efficiency loss due to the secondary flow is reduced and the blowing efficiency is improved.

Means for Solving the Problems In order to achieve the above object, the present invention comprises a motor, a casing attached to a motor frame of the motor, and including an impeller and an air guide, wherein the impeller has a front shroud of the impeller. A short blade that curves at a delay angle with respect to the rotation direction of the impeller protrudes from the upper surface of the outer periphery of the impeller, and the short blade extends integrally with the blade of the impeller.

Effect The electric blower of the present invention has the above-described configuration, in which the short blade that bends at a delay angle with respect to the rotation direction of the impeller protrudes from the upper surface of the outer peripheral portion of the front shroud of the impeller, thereby forming the front shroud of the impeller. The secondary flow, which tends to flow to the suction port of the impeller through the gap between the upper surface and the casing, can be pushed back by the short blade and flow into the motor through the air guide passage. Further, since the short blade is integrally extended with the blade of the impeller, the number of steps for mounting the short blade does not increase, and the impeller can be produced by the same method as in the related art.

Embodiment Hereinafter, an embodiment of the present invention will be described. First, a basic configuration will be described with reference to FIGS. 1 and 2. FIG. Second
As shown in the figure, a casing 21 has an intake hole 22 in the center of the upper surface.
The opening at the lower end is attached to the motor frame 24 of the motor 23 so that there is no air leakage. The centrifugal impeller 25 includes a front shroud 33 and a rear shroud 34.
And a plurality of blades 26 sandwiched between both shrouds 33 and 34, and an air guide 27 is provided below the impeller 25. The casing 21 includes the impeller 25 and the air guide 27, and includes the casing 21 and the air guide.
A diffuser 28 formed by 27 is disposed so as to have a passage that expands toward the outer periphery, and a return passage 29 is formed so as to smoothly and independently communicate with the end of the diffuser 28. The return passage 29 guides the airflow to the intake hole 30 of the motor. The motor 23 is a commutator motor for driving, and the airflow flowing into the intake hole 30 is discharged from the exhaust hole 31 while cooling the inside of the motor.

As shown in FIG. 1, the impeller 25 has a plurality of short blades 32 protruding from an upper surface of an outer peripheral portion of a front shroud 33 of the impeller 25 and curved at a delay angle with respect to the rotation direction of the impeller 25. . The number of the short blades 32 is desirably the same as the number of the blades 26, but is not limited thereto.

In the above configuration, when the impeller 25 is rotated by the motor 23, an airflow is discharged from the impeller outlet 35.
Part of the airflow discharged from the impeller outlet 35 tries to enter the impeller inlet 37 through the gap 36 between the casing 21 and the front shroud 33, but the short blade curved at a delay angle with respect to the rotation direction of the impeller 25. It is pushed back toward the outlet 35 by 32. Thereby, the secondary flow flowing through the gap 36 can be reduced.

One embodiment of the present invention has the basic configuration of the electric blower as described above, and the features of this embodiment will be described below with reference to FIG. As shown in FIG.
On the blade 26, a caulking portion 26a for caulking the front shroud 33 and the rear shroud 34 is formed above and below the blade 26,
A short blade 32 is integrally extended at the tip. The front shroud 33 is provided with a caulking hole 33a and a short blade insertion hole 33b. Also, the rear shroud 34
Is provided with a swaging hole 34a.

In the above configuration, the caulking portion 26a of the blade 26 is inserted into the caulking holes 33a, 34a of both shrouds 33, 34,
Insert the short blade 32 into the short blade insertion hole 3 in the front shroud 33a.
Fig. 3 (b)
The impeller 25 is assembled as shown in FIG.

By this assembling, the impeller can be produced by the same method as the conventional method without increasing the number of steps for attaching the short blade 32, and cost reduction and productivity improvement can be achieved.

Advantageous Effects of the Invention As is clear from the above description, according to the present invention, the secondary blade is formed on the upper surface of the front shroud of the impeller by projecting the short blade curved at a delay angle with respect to the rotation direction of the impeller. Since the flow is pushed back by the short blade and flows into the air guide passage, the amount of the secondary flow is reduced, and an electric blower with high blowing efficiency can be provided.

Further, since the short blade is integrally extended from the blade, it is possible to produce an impeller having a high air blowing efficiency without increasing the number of processes, thereby realizing cost reduction and performance improvement at once.

[Brief description of the drawings]

FIG. 1 is a perspective view of an impeller, FIG. 2 is a partially cutaway side view of an electric blower, FIG. 3 is a sectional side view of a main part of the impeller showing one embodiment of the present invention, (A) is an exploded view, (B) is an assembly drawing,
FIG. 4 is a side sectional view of a conventional impeller, and FIG. 5 is a perspective view of a main part of a conventional electric blower. 21 ... casing, 23 ... motor, 25 ... impeller, 26
…… Blade, 27 …… Air guide, 32 …… Short blade,
33 ... Front shroud.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 51-86666 (JP, U) Japanese Utility Model Sho 61-145899 (JP, U) Japanese Utility Model Sho 51-86664 (JP, U) (58) Field (Int.Cl. ⁶ , DB name) F04D 29/18-29/38

Claims (1)

(57) [Claims] 1. A motor, comprising: a motor; and a casing attached to a motor frame of the motor, the casing including an impeller and an air guide. An electric blower in which a short blade that curves at a delay angle is protruded, and the short blade extends integrally with the blade of the impeller.