JPH04209999A - Impeller - Google Patents

Abstract

PURPOSE:To suppress air leakage to increase air blowing efficiency by inclining impeller blades relative to the vertical plane of a rear shroud and adhering the upper and lower ends of the impeller blades closely on the rear shroud by an elasticity of the impeller blade itself. CONSTITUTION:Outer peripheral ends 16 of impeller blades 15 are perpendicular to a rear shroud 4, and inner peripheral ends 17 of them are twisted relative to longitudinal direction of the impeller blades 15 and provided so that they are inclined relative to the vertical plane of the rear shroud 4, and their top ends 18 are made in contact closely with a front shroud 3. By this, their top ends 18 are forced to return in the direction of arrow a by an elasticity of the impeller blades 15 themselves and their lower ends 19 are forced to return in the direction of arrow b to maintain adhesion of the blades with the front shroud 3 and the rear shroud 4. In addition, the lower ends 19 are crimped in the rear shroud 4 by their edges to prevent air securely from leaking.

Description

[Detailed description of the invention]

[00011

[Field of Industrial Application] The present invention relates to an impeller having a plurality of impeller blades arranged between an umbrella-shaped front shroud and a flat plate-shaped rear shroud. [0002] BACKGROUND OF THE INVENTION In recent years, impellers used in electric blowers for vacuum cleaners and the like are required to prevent air leakage and improve air blowing efficiency. [0003] Conventionally, this type of impeller generally had a configuration as shown in FIG. The configuration will be explained below. [00041] As shown in FIG. An impeller 7 was formed by providing an inducer 6 having an inducer plate 5 within the inner diameter of the impeller 7. [0005] Here, the inner peripheral end 8 of the implant blade 1 and the outer peripheral end 9 of the inducer blade 5 are brought into contact with each other. [0006] Such an impeller 7 was used to construct an electric blower for use in a vacuum cleaner as shown in FIG. [00071 In FIG. 7, the air guide 10 is arranged around the outer periphery of the impeller 7, and the impeller 7 is covered with a casing 11, and is rotated at high speed by a commutator motor 12 to obtain air volume and vacuum pressure. Note that 13 is a suction port of the casing 11, and 14 is an exhaust port. [0008]

[Problems to be Solved by the Invention] In such a conventional impeller, the commutator motor 12 rotates at high speed, so that the airflow passes through the suction port 13 of the casing 11 and from the suction port 2 of the front shroud 3 at high speed. The air flows into the air guide 10, flows into the commutator motor 12, and is exhausted from the exhaust port 14. [0009] Here, the outer peripheral end 9 of the inducer blade 5 of the inducer 6 is the inner peripheral end 8 of the impeller blade 1.
However, since the airflow flowing through the inducer 6 and the impeller blade 1 is at a very high speed and under a high vacuum, the airflow A tends to cause turbulence B at the contact portion. [00101 Figures 8 and 9 are simulation visualizations of the airflow between the inducer 6 and the impeller blades 1. Figure 8 represents the airflow between the impeller blades 1 when the impeller 7 is viewed from above, and Figure 9 represents the airflow on the longitudinal section of the impeller 7. [00111 In both cases, the airflow becomes irregular and becomes a turbulent flow B at the contact portion between the inducer 6 and the impeller blade 1. [0012] This is because the impeller blade 1 is arranged perpendicularly to the rear shroud 4, and the edge portion of the impeller blade 1 comes into linear contact with the three-dimensionally curved front shroud 3, making air leakage more likely. This resulted in a decrease in air blowing efficiency. [00131] The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to bring the upper and lower end surfaces of the impeller blade into close contact with the front shroud and the rear shroud, thereby suppressing air leakage and improving air blowing efficiency. [0014]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an inducer having a plurality of inducer blades, an umbrella-shaped front shroud having a suction port in the center, and a flat plate-shaped rear shroud. A plurality of impeller blades arranged between the rear shrouds are provided, and the impeller blades are inclined at least at the inner circumferential end with respect to the vertical plane of the rear shroud. [0015]

According to the present invention, the impeller blades are brought into pressure contact with the front shroud and the rear shroud due to the elasticity of the impeller blades, thereby reducing air leakage and improving air blowing efficiency. [0016]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Note that components having the same configuration as those of the conventional example are given the same reference numerals, and description thereof will be omitted. [0017] As shown in the figure, the outer peripheral end 16 of the impeller blade 15 is perpendicular to the rear shroud 14,
The inner circumferential end 17 is twisted with respect to the longitudinal direction of the impeller blade 15 and is inclined with respect to the vertical plane of the rear shroud 4. Its upper end surface 18 is in close contact with the front shroud 3, and the lower end surface 19 is in close contact with the rear shroud 4. Closely attached to. [0018] That is, since the inner peripheral end 17 of the impeller blade 15 is twisted and inclined with respect to the rear shroud 4, the upper end surface 18 of the impeller blade 15 tends to return in the direction of arrow a in FIG. 2 due to its own elasticity. , the lower end surface 19 tends to return in the direction of the arrow, so that close contact with the front shroud 3 and the rear shroud 4 is maintained. [0019] Furthermore, the lower end surface 19 bites into the rear shroud 4 at its edge portion, forming an impeller 20 that can firmly prevent air leakage, and rotates at high speed by attaching a commutator motor 12 as shown in FIG. [00201 To explain the operation in the above configuration, FIG.
5 and 5 are simulation visualizations of the airflow at the inducer 6 and the impeller blades 15, respectively. FIG. 4 shows the airflow when viewed from above the impeller 20, and FIG. Although the vacuum pressure near the outer peripheral end 16 of the blade 15 is higher than that at the inner peripheral end 17, the flow velocity is slow and the flow is laminar, so there is little turbulence in the airflow, and even if the twisting force of the impeller blade 15 is small, there is no air leakage. Less is enough. [00212 Near the inner peripheral end 17, the impeller blade 15
Since the pressure difference between the two parts is large and the flow velocity is faster in the front shroud 3 part than in the rear shroud 4 part, air leakage is likely to occur. Therefore, the effect of preventing air leakage is extremely high. [0022] As described above, according to the impeller of the embodiment of the present invention, since the impeller blades 15 are inclined with respect to the vertical plane of the rear shroud 4, the impeller blades 15 are moved toward the front shroud 3 due to the elasticity of the impeller blades 15 themselves. Pressure welds to reduce air leakage, for example, main body power is 30
When used in an electric blower for a 0W vacuum cleaner, the vacuum pressure is about 2000 mm of water column, but the loss due to air leakage was conventionally as high as 50 mm of water column, which significantly reduced the air blowing efficiency, but the present invention With this, there is almost no loss due to air leakage, and the air blowing efficiency of the electric blower can be significantly improved. [0023]

[Effects of the Invention] As described above, according to the present invention, since the impeller blades are inclined with respect to the vertical plane of the rear shroud, the upper and lower end surfaces of the impeller blades are respectively It can be in close contact with the front shroud and the rear shroud, suppressing air leakage even at the impeller inlet where the air flow inside the impeller is fast, and improving air blowing efficiency.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an impeller according to an embodiment of the present invention.

[Figure 2]
Enlarged cross-sectional view of the impeller near the inner peripheral end of the impeller blade

[Figure 3] Partially cutaway side view of an electric blower equipped with the same impeller

[Figure 4] Simulation visualization of airflow inside the impeller

[Figure 5] Simulation visualization of airflow inside the impeller

[Figure 6] Partial vertical cross-sectional view of a conventional impeller

[Figure 7] Partially cutaway side view of an electric blower equipped with the same impeller.

[Figure 8] A simulation visualization of the airflow inside the same impeller.

[Figure 9] A simulation visualization of the airflow inside the same impeller: “

[Explanation of symbols]

2 Suction port 3 Front shroud 4 Rear shroud 5 Inducer blade B Inducer 15 Impeller blade 17 Inner peripheral end

[Figure 4]

Claims (1)

[Claims] 1. An inducer having a plurality of inducer blades, and a plurality of impeller blades arranged between an umbrella-shaped front shroud having a suction port in the center and a flat plate-shaped rear shroud, the impeller having a plurality of inducer blades. An impeller in which the blades are inclined at least at the inner circumferential end with respect to the vertical plane of the rear shroud.