JPH0318697A - electric blower - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric blower used in a vacuum cleaner or the like.

2. Description of the Related Art A conventional electric blower of this type has an impeller as shown in FIG. 6, or a structure as shown in FIGS. 6 to 9, for example. That is, an impeller 4.14 is formed in the rear shroud 1.11 in which three-dimensionally shaped long blades 2.12 and short blades 3, 13 are arranged alternately to guide the axial flow toward the outer circumference. Said long blade 2.1
The suction side edges 21L, 121L of the impeller 4.14 are formed in a straight line from the approximate center to the outer periphery of the suction ports 4B, 14& of the impeller 4.14. 6.15 are impellers 4 and 14 respectively
This is an air guide placed around the outer periphery of the air guide.

The impeller 14 was covered with a casing 16 and rotated at high speed by a button and commutator motor 16 to obtain air volume and vacuum pressure. The airflow velocity at the outer periphery of the suction side edge 12a of the housing is shown as v, and approximately at the center is shown as 72.

Problems to be Solved by the Invention However, the impeller 4.1 used in the above-mentioned electric blower
Impeller 4 rotates at a very high speed.
, 14 airflow flows at high speed from the suction ports 4K, 14flL. The air is then guided into the impeller 4.14 through the suction side edges 2fi, 12a of the blades 2, 12, and flows into the air guide 5.15. Here, when considering the airflow at the suction side edges 21, 12&, the outer circumference of the suction side edges 2a, 122L is v
1 has a faster circumferential speed than the substantially central portion v2, so the speed of the air flowing in is faster. That is, the suction side edges 21,1
Air currents with different speeds flow from approximately the center to the outer periphery of 2&, resulting in turbulence in the flow speed. This leads to a decrease in the air blowing efficiency of the impellers 4 and 14 and an increase in noise.

SUMMARY OF THE INVENTION In order to solve the above problems, it is an object of the present invention to provide an electric blower that can smoothly flow air into an impeller without disturbance.

Means for Solving the Problems In order to achieve the above objects, the present invention provides an impeller in which a plurality of three-dimensionally shaped long blades and short blades are arranged alternately on the rear shroud for guiding the axial flow toward the outer circumference. The suction side edge of the long blade has a substantially curved shape that recedes from the substantially center of the suction port toward the outer periphery with respect to the impeller rotation direction.

In the impeller of the present invention, the suction side edge of the long blade has a substantially curved and tapered shape that recedes in the direction of rotation from the approximate center of the suction port toward the outer periphery. Because the speed of the incoming airflow is the same,
Since there is less turbulence in the flow velocity, it is possible to improve the air blowing efficiency of the impeller and reduce noise.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings.

FIGS. 1 to 4 show an embodiment thereof, in which 21 is a casing, and an intake hole 22 is opened in the center.

The opposite side of the air intake hole 22 is attached to an air guide 23 so as to prevent air leakage. Reference numeral 24 denotes an impeller having a suction port 26 in the center and a plurality of three-dimensionally shaped long blades 27 and short blades 28 arranged alternately to guide the axial flow toward the outer circumference of the rear shroud 26. The suction port 26 side of the long blade 27 is defined as a suction side edge 27a,
This suction side edge 27a has a substantially curved shape that recedes from the substantially center of the suction port 26 toward the outer periphery with respect to the rotational direction of the impeller 24. The velocity of the airflow near the approximate center of the suction side edge 27& of the housing is set as ▼5, and the speed near the outer periphery is set as 74. 30
This is a commutator motor for driving the impeller 24, and 31 is its exhaust port.

When the impeller 24 starts to rotate at high speed by the commutator motor 30 due to the above-mentioned loss, the impeller 24 is
The airflow flows into the inside of the motor 4, and the airflow discharged from the impeller 24 is guided to the air guide 23 and is exhausted from the exhaust port 31 while cooling the commutator motor 30.

Here, the long blade 27 through which the airflow flows into the impeller 24
When considering the flow velocity of the airflow near the suction side edge 27a at the tip, the flow velocity at approximately the center is expressed as ▼, . The flow velocity at the outer periphery is ▼4
In this case, since the suction side edge 27a has a substantially curved shape that recedes toward the outer circumference with respect to the rotation direction of the impeller 24, the airflow on the outer circumference is delayed and drawn into the impeller 24. Therefore, the outer peripheral speed v2 tends to become slower. In other words, the peripheral speed ▼4 is approximately the center speed ▼5.
As a result, the velocity of the airflow near the suction side edge 27 is made uniform, resulting in less turbulent airflow, improving the air blowing efficiency of the impeller and reducing noise.

Effects of the Invention As described above, the present invention improves the air flow at the impeller suction section by forming the suction side edge of the long blade into a substantially curved shape that recedes from the approximate center of the suction port toward the outer periphery with respect to the impeller rotation direction. Since the speed at which the air flows into the air is uniform at all positions, turbulence can be prevented, making it easier to improve the impeller's air blowing efficiency and reduce noise.

[Brief Description of the Drawings] Fig. 1 is a half-cut sectional view of an electric blower showing an embodiment of the present invention, Figs. 2 and 3 are plan and side sectional views of the same impeller, and Fig. 4 is Figure 6 is a partial perspective view of the suction section of the impeller, Figure 6 is a partial plan view of a conventional impeller, Figure 6 is a half-cut sectional view of a conventional electric blower, and Figures 7 and 8 are plan views of the same impeller. The button and side sectional view, and FIG. 9 is a partial perspective view of the suction portion of the same impeller. 24... impeller, 26... mountain shroud, 27... river... long blade. 27a... Suction side edge, 28. River... Short blade.

Claims (1)

[Claims] It has an impeller in which a plurality of three-dimensionally shaped long blades and short blades are arranged alternately on the rear shroud to guide the axial flow toward the outer circumference, and the suction side edge of the long blade is connected to the suction port. An electric blower with a substantially curved shape that recedes from the center to the outer circumference with respect to the impeller rotation direction.