JPH01257796A - Impeller of centrifugal fan - Google Patents

Abstract

PURPOSE:To improve efficiency of the title impeller in such a way as to mini mize loss regardless of any leakage generated between calked parts by providing such constitution as inhibiting existence of calked parts of adjacent blades on concentric circles. CONSTITUTION:The impeller 12 of a centrifugal fan is composed of a front shroud 21, a rear shroud 22 and plural blades 24a, 24b integrated in one body with plural calked parts 23 arranged between those shrouds. The lengths of those blades 24a, 24b are made different from each other. Further, the positions of the calked parts 23 staying between blades 24a, 24b adjacent in a circumferential direction are not arranged in the same circumference. Therefore, the air flow caused by its leakage is obstructed by an adjacent calked parts 23 so as not to flow in the circumferential direction even if any clearance is generated between these calked parts 23.

Description

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

Conventionally, this type of impeller has a front shroud 1 and a rear shroud 2 made of sheet metal, and is located between the two shrouds 1 and 2, as shown in FIGS. 7 and 8. The blade 3 is integrally caulked by caulking portions 4 located in concentric circles.

In the configuration described in -1-, the impeller 5 rotates at high speed to generate airflow and suction pressure.

Problems to be Solved by the Invention However, in the impeller 5 having such a configuration, due to limitations in mold accuracy and non-uniformity of the sheet metal material (non-uniformity in thickness and ductility direction), as shown in FIG. In addition, a minute gap 6 will be created between the front shield 1 and the play 1'3, which are the tangent lines of the three-dimensional curves. These gaps 6 do not exist because the caulking force is exerted on the caulking portions 4, but are formed between the caulking portions 4. Furthermore, since the caulked portions 4 are located on concentric circles, the gaps 6 are also formed on concentric circles. As a result, when the impeller 5 rotates, the airflow leaks through the gap 6 in the circumferential direction, causing a decrease in the efficiency of the centrifugal blower2.
Furthermore, since there are many plates 3 in the suction core of the impeller 5, the airflow tends to flow into the impeller 5, which is also one of the causes of reduced efficiency.

The present invention solves these problems, and aims to provide an impeller for a centrifugal blower with high air blowing efficiency by changing the length of the plates in the impeller and devising the position of the caulking part. That is.

Means for Solving the Problems And in order to achieve the above object, the impeller of the centrifugal blower of the present invention includes a front shroud, a rear shroud, and a plurality of shrouds disposed between them and integrated with a plurality of caulked parts. The blades have different lengths, and the positions of the caulking portions between circumferentially adjacent blades are shifted from the same circumference.

Operation In the above configuration, adjacent and
Since the caulking part of the blade is constructed so that it does not exist on concentric circles, gaps do not exist consecutively on concentric circles, and the flow due to leakage that occurred in conventional t) is prevented and efficiency is improved. On the other hand, since the lengths of the plates 1 and 2 are uniform, the number of plates can be reduced at the impeller suction port, making it easier for airflow to flow into the impeller. Combined with the 414 configuration of the caulked portion, the air blowing efficiency can be increased.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In FIGS. 1 to 4, 10 is a motor, 11 is its rotating shaft, and 12 is an impeller fixed to the rotating shaft 11.

Reference numeral 13 denotes an air guide located on the outer periphery of the impeller 12, which has an enlarged passage 14 in which passage serum gradually expands, and a return passage 15 following this. 16 is a casing that covers the impeller 12 and the air guide 13, and the motor bracket 1
7 is press-fitted and fixed. IS is a suction port, one is a bearing on the impeller side, and 20 is a bearing holding portion on the opposite side to the bearing 19.

The impeller 12 of item 1 is composed of a front shroud 21 and a rear shroud 22 made of sheet metal, and a plurality of blades 24 disposed between these and integrated with a plurality of caulking parts 23. It consists of blades 24a and 24b having different lengths, and the positions of the caulking parts 23 between blades adjacent in the circumferential direction are all offset from the same circumference -1-.

When the impeller 12 with the above configuration is used, the congestion of the plates 24 of the suction port 18 in the impeller 12 can be reduced compared to the conventional one, and the airflow can be smoothly flowed in, and each plate In No. 24, the positions of the caulking portions 23 of adjacent blades in the circumferential direction are shifted, so even if a gap is created between the plate 24 and the front shroud 21, the blades will not close due to the influence of the caulking force of the adjacent plate 24. The pulling force between the front shroud 24 and the front shroud 21 is strong (so that gaps are less likely to form).Therefore, the air blowing efficiency is very high.

Moreover, even if a gap occurs, the flow due to leakage will be blocked by the adjacent caulked portion 23 and will no longer flow in the circumferential direction, so that the loss unlike the conventional one will be significantly reduced.

Next, in the embodiment shown in FIG. 5, only the innermost and outermost caulked portions 23 of the impeller 12 are located on the same circumference, and the other caulked portions 23 are not located on the same circumference. Configuring. This embodiment also provides the same effects as described above.

FIG. 6 shows one embodiment in which only the innermost caulking portion 23 of the short blade 24a is located offset from the same circumference of the caulking portion 23 of the long blade 24b. This embodiment also provides the same effects as described above.

Effects of the Invention As described above, in the impeller of the centrifugal blower of the present invention, the caulking portions of adjacent blades are configured so that they do not exist on concentric circles, so that gaps do not exist in two consecutive concentric circles. This prevents the flow caused by leakage that occurs in conventional models, and the moving element moves in the opposite direction.At the same time, since the plates have different lengths, the number of plays at the impeller suction port is increased. This has the effect of making it easier for the airflow to flow into the impeller and, in combination with the structure of the caulked portion, increasing the air blowing efficiency.

[Brief explanation of the drawing]

FIG. 1 is a 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.
Figures a and b are explanatory diagrams of the blade shape of the same impeller, Figure 4 is a partially cutaway side view of an electric blower equipped with the same impeller, and Figures 5 and 6 are illustrations of the impeller cut away. 7 is a plan view showing a conventional impeller, FIG. 8 is a side sectional view of the same impeller, and FIG. 9 is a plan view of another embodiment.
The figure is an enlarged sectional view of the main part. 12... Impeller, 21... Front shroud, 22
... Rear shroud, 23... Caulking part, 24...
・Plate, name of agent Patent attorney Toshio Nakao and 1 other figure 6? 3 Figure 7

Claims (1)

[Claims] It consists of a front shroud, a rear shroud, and a plurality of blades disposed between these and integrated by a plurality of caulking parts, and the blades have different lengths and a gap between adjacent blades in the circumferential direction. An impeller for a centrifugal blower in which the position of the caulked part is shifted from the same circumference.