JPS60233396A - Fan for electric vacuum cleaner - Google Patents

Abstract

PURPOSE:To improve ventilating efficiency and prevent deformation upon assembling as well as the abnormal vibration of the fan by a method wherein the radius of curvature of shoulder section of a casing is formed larger than the height of entrance of an air guide to improve the rigidity of the casing and smoothen the flow of air stream. CONSTITUTION:The radius R of curvature of the shoulder 41 of casing 34 is formed larger than the height of entrance of the air guide 30, therefore, air, flowing from an impeller 21 toward the outer peripheral direction, is changed into the downward stream of a communicating path 32 along the radius of curvature R of shoulder 41 of the casing 34 smoothly and there is no possibility to be deflected by right angle or stagnated as before. According to this method, flow regulating effect, achieved by the air guide 30, may be maintained in a high level and the ventilating efficiency of the fan may be improved. Further, the rigidity of the casing 34 is improved, deformation caused upon assembling may be reduced, the abnormal vibration or the like of the casing 34 may be eliminated and noise may be reduced remarkably.

Description

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

Structure of the conventional example and its problems As shown in FIG. A plurality of volute chambers 4 are provided in the volute chamber 4, and from the volute chamber 4,
Passage 6 surrounded by fan case 3 and ventilation guide 2
The volute chamber 4 is formed by connecting a passage 6 formed below the impeller 1 to the air discharged from the outer circumference of the impeller 1.
→ Passage 6 → Passage 6 → Inside of motor 7 → Motor exhaust port 8
was flowing.

Therefore, in this type of electric blower, as shown in Fig. 2, in order to divert the air discharged by the impeller 1 and flowing toward the outer circumference from the passage 6 to the passage 6 due to centrifugal force, Energy loss occurs at the bend,
The air blowing efficiency was not very good at around 30 factors. In particular, the flow stagnates within the shoulder portion 9 of the fan case 3, which has the drawback of interfering with the rectifying effect of the air guide.

OBJECTS OF THE INVENTION The present invention overcomes these conventional drawbacks and provides a highly efficient electric blower.

Structure of the Invention In order to achieve this object, the blower for a vacuum cleaner of the present invention has a plurality of volute chambers provided on the outer periphery of an impeller, and the volute chambers smoothly guide air toward the outer periphery. A communication path is provided that communicates from the air guide to the lower part of the air guide.
The aim is to eliminate stagnation in the airflow and improve ventilation efficiency.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a cross section of a blower for a vacuum cleaner according to an embodiment of the present invention. In FIG. 3, reference numeral 21 denotes an impeller, with a suction port 22 opening at the front of its central portion, and a plurality of blades 23 provided around its outer periphery. The blade 23 is sandwiched between side plates 24 and 25 on both sides, and the outer periphery 26 is open. A shaft 28 of an electric motor 27 penetrates into the center of the impeller 21, and is fastened to the shaft 28 with a nut 29. 3o is an air guide made of a resin molded product, and includes a plurality of volute chambers 3 provided facing the outer periphery of the impeller 21.
1. A communication passage 32 that guides the volute chamber 31 to the outer periphery and goes around from the outer periphery to the back side, and a plurality of air passages 3 that go inward on the back side.
7 is formed. The communication passages 32 are divided by guide wings 32a, and above the air guide 30, each communication passage 3
2 are independent. The communication passage 32 continues downward on the outer periphery of the air guide 30, so that air flows downward through the air guide 30. 33 is an air guide inlet communicating with the communication path. The casing 34 surrounds the outer periphery of the air guide 30 and forms a communication path 32 together with the air guide 30, and also covers the front of the impeller 21, with a suction port 35 opposite the suction port 22 of the impeller 21 opening in the center of the casing 34. are doing. The casing 34 is still press-fitted onto the outer periphery of the bracket 36 of the electric motor 27 at the lower part of its outer periphery. When the back side of the air guide 30 is shown in FIG.
2 to an air passage 37 heading inside the air guide 30, and is divided by guide vanes 38. air passage 3
7 join at an inner end 39 thereof, and opposite to this inner end 39, an intake port 4o is provided in the bracket 36 of the electric motor 27.

The shoulder portion 41 of the casing 34 is formed to have a radius larger than the entrance height of the air guide.

The operation of the vacuum cleaner blower configured as described above will be described below.

As the electric motor 27 operates, the impeller 21 rotates together with the shaft 28. Therefore, the air flows from the suction port 36 of the casing 34 to the suction hole 22 of the impeller 21 to the inside of the impeller 21, is pushed by the blades 23, and is discharged from the outer periphery 26. Furthermore, the air is transferred to the guide blade 3 of the air guide 3o.
2a, and flows through the communication path 32 toward the outer circumference. The air that has entered the lower part of the air guide 30 through the communication passage 32 flows through the air passage 37 by the guide vane 38, and flows from the inner end 39 to the intake hole 4o to the inside of the electric motor 27, thereby cooling the electric motor 27.

To explain the air flow in the communication passage 32 in more detail, as shown in FIG. The airflow flowing in the direction smoothly flows along the radius of the shoulder 41 of the casing 34.
The flow changes to flow downward through the communication path 32, and there is no need for the flow to change at right angles or for air to stagnate as in the conventional case. Therefore, the rectifying effect of the air guide 30 is maintained high, and the air blowing efficiency can be increased more than that of conventional blowers. Furthermore, since the shoulder portion 41 of the casing 34 is formed with a radius larger than the height of the air guide inlet, the rigidity of the casing is improved, deformation during assembly is reduced, and the defective rate during assembly is reduced. In addition, even if vibrations during operation of the electric motor 2 are transmitted to the casing 34 from the press-fitted part of the bracket 36, the casing 34
There is no possibility that abnormal vibrations will occur due to lack of rigidity.

According to experiments, the outer diameter of the impeller 21 was 1089, the number of blades 23 was 11, and the outer diameter of the air guide 30 was 136.
When the number of blades and guide vanes 32a was set to 16, the height A of the air guide inlet 33 (Fig. 6) was set to 6.5111B, and the R of the shoulder portion 41 of the casing 34 was examined, R)A
It has been found that the air blowing efficiency can be increased by doing so. In order to obtain high air blowing efficiency (for example, 42%), R = 1A ~
1.3A was sufficient, and a range of R=7 to 8 m was particularly good.

In particular, when R=am, the highest value of air blowing efficiency was obtained. In this embodiment, the number of guide blades 32a is 16, and the impeller 21 is
In the explanation, the number of blades 23 is 11, but the number may be larger or smaller, but according to the results of experiments, the number of guide vanes is 4 to 20, and the number of blades is about 6 to 13, which are almost the same. effect can be obtained. In addition, in this embodiment, the radius of R of the shoulder portion 41 of the casing 34 is set to be larger than the height A of the air guide inlet portion 33, but the shoulder portion p 1
The same effect can be obtained even if R is formed as a quadratic curve that is apparently larger than the height A of the air guide inlet portion 33.

In addition, the same effect should be obtained with the air guide 30 of the type without guide vanes 32a on the outer periphery of the impeller 21, but since the air coming out from the impeller outer periphery does not flow to an independent passage, the rotational speed of the impeller The streamline direction of the air flow varies depending on the outlet shape, the dimensions between the impeller outer diameter and the casing outer diameter, etc., and the relationship between the radius of the radius of the casing shoulder and the height of the air guide is fixed. I can't do it.

Effects of the Invention As described above, the present invention provides a plurality of volute chambers (passages) on the outer periphery of the impeller, and the volute chambers smoothly guide air toward the outer periphery, and the air flows around from the volute chamber to the back side of the air guide. A communication path is formed by an air guide and a casing surrounding the outer periphery of the air guide, and
By forming the radius of H on the casing shoulder to be larger than the height of the air guide inlet, the air flow changes smoothly and there is no stagnation, resulting in high air blowing efficiency.

■ The rigidity of the casing is improved and the rate of defects due to deformation during assembly can be reduced.

■ The rigidity of the casing is improved, eliminating abnormal vibrations of the casing, leading to a reduction in noise.

You can obtain effects such as, and the value is like a dog.

[Brief Description of the Drawings] Fig. 1 is a perspective view of a conventional vacuum cleaner blower, Fig. 2 is a partial sectional view thereof, and Fig. 3 is a partial sectional view of a vacuum cleaner blower according to an embodiment of the present invention. , FIG. 4 is a top view of the same, FIG. 6 is a plan view of the back side of the air guide section, and FIG. 6 is a partial sectional view for explaining the same operation. 21... Impeller, 30... Air guide,
31... Volute chamber, 32... Communication passage, 34...
Casing, 41...Shoulder. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] An impeller, a plurality of volute chambers provided opposite to the outer periphery of the impeller, and the volute chambers guided to the outer periphery;
An air guide having a communication passage that extends from the outer periphery to the back side, and an air passage that goes inward on the back side and guides exhaust air to the intake port of the electric motor, and surrounds the outer periphery and upper surface of the impeller and the air guide, A blower for a vacuum cleaner, comprising: a casing that forms the communicating path together with the air guide, and has a shoulder portion formed with a radius larger than the height of the inlet of the air guide.