JPH01300098A - Impeller of centrifugal blower - Google Patents

Abstract

PURPOSE:To improve air blowing efficiency and reduce generation of noise by composing an impeller of blades of at least two kinds of long and short lengths, and inclining a tip edge on the intake side of short blade. CONSTITUTION:A blade of impeller 12 is composed of long and short blades 24a, 24b, and the tip edge on an intake port 25 side of the short blade 24b is formed such that a front shroud 21 side 27 is recessedly inclined substantially lineary to an blow out side 28. Consequently, the density of blades of intake port 25 in the impeller 12 is alleviated, and due to this flow arrangement effect, air flow can be smoothly flowed in. Since the arranged air flow collides on the short blade 24b with time lags, it is possible to improve air blowing efficiency, reduce noises and provide extremely high quality impellers 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an impeller for a centrifugal blower for generating suction pressure used in a vacuum cleaner or the like.

2. Description of the Related Art Conventionally, as shown in FIG. 7, an impeller of this type has a front shroud 1 and a rear shroud 2 made of sheet metal, and blades 3 located between the two shrouds 1.2.
These are caulked and integrated by caulking portions 4 located on concentric circles.

In the above configuration, the impeller 5 rotates at high speed to generate airflow and suction pressure.

Problems to be Solved by the Invention However, since there are a large number of blades 3 at the suction port of the impeller 5 having such a configuration, it becomes difficult for airflow to flow into the impeller 5, and this is the cause of the reduction in efficiency. They had become one. As a countermeasure against such a decrease in efficiency, an impeller 8 having two types of blade lengths, long blades 6 and short blades 7, as shown in FIG. 8, has been devised. In such an impeller 8, the incoming airflow that has been rectified by the long blades 6 inside the impeller 8 collides with the tip edge 9 of the short blade 7 on the suction port side, causing abnormal noise, and the overall noise is increased. It had the problem of getting bigger.

The present invention solves these problems by making the lengths of the blades in the impeller different and by devising the shape of the tip edge of the short blades on the suction port side, thereby creating a centrifugal blower with high air blowing efficiency and low noise. The purpose is to provide impellers.

Means for Solving the Problems And in order to achieve the above object, the impeller of the centrifugal blower of the present invention has two or more types of blade lengths, long and short, and the tip edge of the short blade on the suction port side is sloped. It is something.

Effect In the above configuration, the blades in the impeller have different lengths, so the number of blades can be reduced at the suction port of the impeller, making it easier for airflow to flow into the impeller, and increasing the flow inside the impeller. In this case, the rectified airflow will not collide with the tip edge of the short blade at the same time (
Since the collisions occur at different times, the energy of the collisions is alleviated, and in combination with the configuration of the number of blades described above, it is possible to increase the air blowing efficiency and reduce noise.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In FIG. 6, 10 is a motor, 11 is its rotating shaft, 1
2 is an impeller fixed to the rotating shaft 11. An air guide 13 is located on the outer periphery of the impeller 12, and has an enlarged passage 14 whose passage area gradually increases and a return passage 15 following the enlarged passage 14. A casing 16 covers the impeller 12 and the air guide 13, and is press-fitted into the motor bracket 17 and fixed thereto. 18 is a suction port, 19 is a bearing on the impeller side, and 20 is a bearing holding portion on the opposite side to the bearing 19.

1 to 4 show embodiments of the present invention, and the impeller 12 described above is integrated with a front shroud 21 and a rear shroud 22 made of sheet metal by a plurality of caulking parts 23 disposed between them. The blades 24 have different lengths, and the long blades 24 have different lengths.
4a and short blades 24b, and the shape of the tip edge of the 25 examples of the suction ports of the short blades 24b is made such that the front shroud 21 side 27 is receded approximately linearly from the rear shroud 22 (1126) toward the air outlet 28 side. It is tilted at an angle.

When the impeller 12 having the above configuration is used, the congestion of the blades 24 of the suction port 25 in the impeller 12 can be reduced compared to the conventional one, and this rectifying effect allows the airflow to flow smoothly. Inside the impeller 12, the rectified airflow collides with the tip edge of the short blade 24b with a time lag.
An extremely high quality impeller with high air blowing efficiency and low noise can be obtained.

Next, FIG. 5 shows another embodiment, in which the shape of the tip edge of the short blade 29 of the impeller 12 on the suction port 25 side is changed from the front shroud 21 side 30 to the rear shroud 22 [31].
The air outlet 28M is tilted back toward the air outlet 28M in a substantially straight line.

In this embodiment, the motor 10f is guided by the shape of the tip edge of the short blade 29 on the suction port 25 side.
This has the additional effect of increasing efficiency since it is guided to lil.

Effects of the Invention As described above, in the impeller of the centrifugal blower of the present invention, the length of the blades is made up of two or more types, long and short, and the tip edge of the short blade on the suction port side is sloped.
At the suction port of the impeller, the number of blades can be reduced to rectify the airflow into the impeller and make it easier to flow in. Inside the impeller, the rectified airflow is It is possible to reduce the generation of collision noise.Therefore, the effects of increasing air blowing efficiency and reducing noise can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of an impeller of a centrifugal blower showing an embodiment of the present invention, FIG. 2 is a sectional view of the same side, and FIG. Figure 4 is an explanatory diagram of the short blade shape of the same impeller, Figure 5 is a side sectional view of an impeller of another embodiment, and Figure 6 is a partially cutaway side view of an electric blower equipped with the impeller of the present invention. 7 and 8 are side sectional views showing conventional impellers. 12... Impeller, 21... Front shroud, 22
...Rear shroud, 24b, 29...Short blade. Agent's name: Patent attorney Toshio Nakao and 1 other person 2 Figure 22
-, rear shroud Fig. 3 Fig. 4 2z 3/ Fig. 6

Claims (1)

[Claims] It consists of a front shroud, a rear shroud, and a plurality of blades arranged between these and integrated by a plurality of caulking parts, and the blades have two or more lengths, long and short, and a short length and a short length. A centrifugal blower impeller with a sloped tip edge on the suction side of the blade.