JPS5974396A - Motor fan - Google Patents

Abstract

PURPOSE:To eliminate air flow between a casing and an impeller for improving the efficiency of a fan by providing an annular rib having diameter larger than the outer diameter of the impeller and projecting from the surface of the casing opposed to the impeller. CONSTITUTION:When an impeller 12 is rotated, air flow 15 from the impeller 12 is hindered by an annular rib 14 of a casing 11 to flow in an air guide 13 without entering a gap 16 between the casing 11 and the impeller 12, and thus a circulating flow will not occur. Also, since the size of the gap between the impeller 12 and the casing 11 can be maintained similarly to the conventional one, the impeller 12 does not contact the casing 11 dangerously.

Description

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

Figure 1 shows a conventional electric blower used in vacuum cleaners, etc. In other words, 1 is a casing, and an air intake port 2 is formed in the center of the earthen part of the casing. The opposite side is attached to the motor frame 3 to prevent air leakage. 4 is an impeller - by rotating it, kinetic energy, that is, dynamic pressure,
Generates pressure energy, ie static pressure. Reference numeral 6 denotes an air guide in which a volute portion 6a for converting the dynamic pressure generated by the impeller 4 into static pressure and an exhaust passage 5b for guiding the exhaust gas 6 into the inside of the motor are integrally formed.

6 is a motor. By rotating the motor 6, the airflow is directed from the intake port 2 of the casing 1 to the inside of the impeller 4.
The air passes through the air guide 6 → inside the motor 6 and is discharged to the outside.

Now, let's pay attention to the gap γ between the impeller 4 and the casing 1. By rotating impeller 4.

The pressure is lowest 1 near the inlet portion 8 of the impeller 40. As a result, air is sucked in through the inlet 2 of the casing 1 - not only through the inlet 2 but also through the gap 9 between the back side of the inlet 2 of the casing 1 and the impeller inlet. It turns out. Due to this,
An airflow 1o will be generated in the gap 7 between the impeller 4 and the casing 1. This airflow 1o will flow between the inside of the impeller and the gap 7.
This becomes a circular flow that circulates between Since this circulating flow does no work for the outside, it results in a loss for the blower as a whole, and this is one of the causes of poor fan efficiency. An easy way to eliminate this circulation flow and reduce losses is to
, 9 may be made smaller to make it difficult for the air to flow all at once. However, this method is difficult to implement for the following reasons.

That is, if the gap is made smaller, impeller 4
If the fixing direction of the impeller 4 suddenly changes while it is rotating (such as when the vacuum cleaner falls over while the blower is installed in the vacuum cleaner), the outer edge of the impeller 4 may swing due to the gyro. There is a possibility that it will collide with casing 1. Furthermore, even when the gap 9 is made smaller, there is a possibility that the casing 1 and the impeller 4 will come into contact with each other.

The purpose of the present invention is to increase fan efficiency by eliminating the above-mentioned circulating flow, and to achieve good rotational operation of the inflator.To this end, in the electric blower of the present invention, the impeller of one casing is opposed to the other. It has a structure in which an annular lip with a diameter larger than the outer diameter of the impeller is protruded from the surface of the impeller. is maintained at a value that does not interfere with the rotational operation of the impeller.

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

In FIG. 2, 11 is a casing, and 12 is an impeller 13 is an air guide.The casing 11 has an annular lip 14 facing the impeller 12 and having a diameter larger than the outer diameter of the impeller. It is a protruding structure.

In the above configuration, when the impeller 12 is rotated, the air flow 16 coming out of the impeller 12 flows through the casing 11.
The air flows into the air guide 13 without entering the gap 16 between the casing 11 and the impeller 12 because it is obstructed by the annular rib 14 of the air, so that no circulating flow occurs. Further, since the size of the gap between the impeller 12 and the casing 11 can be maintained as in the conventional case, there is no possibility of the impeller 12 and the casing 11 coming into contact with each other.

As described above, according to the present invention, the circulating flow that has conventionally occurred in the blower is increased, and the loss can be reduced to 1.

Therefore, according to the present invention, a blower with high efficiency can be obtained easily.

Also, since the annular lip has a larger diameter than the impeller,
The gap between the impeller and the casing can be set to a sufficient value that remains the same as before.

This can prevent damage caused by contact between the two, and also allows one impeller to rotate smoothly, further increasing efficiency.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of a conventional electric blower, and FIG. 2 is a cross-sectional view of essential parts of an electric blower according to an embodiment of the present invention. 11...Casing-12...Impeller 14...Rep. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] An electric blower in which an annular rib having a diameter larger than the outer diameter of the impeller is protrudingly installed on the surface of the casing facing the impeller.