JPH05133398A - Blower - Google Patents

Abstract

PURPOSE:To get an axial blower which has a large air quantity and low noise and improves its pressure properties and makes full use of its features in a low load area. CONSTITUTION:This blower is equipped with an orifice which surrounds an axial impeller entirely, and it is composed of some or all circular parts 5a and straight parts 5b on the suction side, in respect of the cross section of the said orifice, and a circular part 5c on discharge side, and the radius of the circular part on the suction side is made larger than the radius of the circular part 5c on the discharge side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower used in an air conditioner or the like.

[0002]

2. Description of the Related Art A conventional blower of this type has a structure in which a substantially cylindrical orifice 2 is arranged on the outer periphery of an impeller 1 as shown in FIG. (Tokukaihei 2-29869
(See No. 7) The hub portion of the impeller 1 is provided with a boss portion that connects the shaft of the motor 3 so that the motor 3 rotates the impeller 1. By the rotation of the impeller 1,
The flow indicated by the arrow a was generated to perform the air blowing action.

Here, in order to make up for the basic drawback that the axial flow impeller can obtain a small pressure, various modifications have been made to the shape of the orifice 2 and efforts have been made to obtain high pressure with the axial flow impeller. For example, the discharge side of the orifice 2 is made narrower than the suction side so that the flow on the discharge side does not flow back to the suction side.

[0004]

However, in the case of performing the air blowing action with the above-described structure, generally, noise increases and the air volume in the high pressure region increases, but the air volume on the release side decreases. Since it will end up with a low load, a large air volume, and
There was a problem that it was not useful when low noise was required.

The present invention solves the above-mentioned conventional problems, and aims to provide a blower with a large air volume and low noise, in which the pressure characteristics are improved and the characteristics of the axial flow impeller in the low load region are fully utilized. It is what

[0006]

In order to solve the above-mentioned problems, a blower of the present invention comprises an axial flow or mixed flow impeller and an orifice surrounding the outer circumference of the impeller, and the cross-sectional shape of the orifice is suction. Side arc portion, a straight line portion and a discharge side arc portion, the suction side arc portion has a larger arc radius than the discharge side arc portion, and further the outermost periphery of the impeller The axial position of the edge is set within the range of the axial position of the discharge side arcuate portion.

[0007]

According to the present invention, most of the impeller is brought out to the suction side of the orifice by the above-mentioned constitution, and the inflow is made not only from the front side of the impeller but also from the side surface, so that the inflow area is widened and the suction resistance is improved. Can be lowered. Further, since the discharge side of the orifice is formed as an arc, the flow in the vicinity of the orifice flows out while spreading along the discharge side arc portion, and the effect of centrifugal force due to the radial flow is added to obtain sufficient pressure characteristics. ..

[0008]

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

In FIG. 1, 4 is an impeller, 5 is an orifice, and 6 is a motor. The cross section of the orifice 5 is formed of a suction arc portion 5a, a straight line portion 5b and a discharge side arc portion 5c. Here, the radius of the discharge side arc portion 5c is smaller than the radius of the suction side arc portion 5a.

Further, the positional relationship between the impeller 4 and the orifice 5 is such that the axial position of the outermost peripheral trailing edge 4a of the impeller 4 is within the range of the discharge side arc portion 5a.

With the above construction, the suction area of the impeller 4 becomes large, and the suction resistance does not become large even when the air volume is large. That is, the flow flowing into the impeller 4 is indicated by the arrow b.
In addition to the flow from the front shown by, the inflow increases from the side surface of the impeller 4 indicated by the arrow c, the inflow velocity is small even when the air volume is large, and the inflow resistance does not increase so much. Also,
The flow passing in the vicinity of the orifice 5 flows out along the discharge-side arcuate portion 5c of the orifice 5 as shown by an arrow d, and thus has a velocity component outward in the radial direction. For this reason, the entire discharge flow becomes a slight oblique flow from the axial flow, and the pressurizing effect due to the centrifugal force is added, so that sufficient pressure characteristics can be obtained.

FIG. 2 shows a comparison of the PQ characteristics of a conventional air blower of this type and the air blower of the present invention, in which the air blower of the present invention exhibits airflow type characteristics and It can be seen that the noise is low.

[0013]

As described above, according to the air blower of the present invention, the relative position of the orifice and the impeller is set so that the suction area of the impeller is widened. The suction resistance is kept small without being too large, and as a result, low noise is maintained even with a large air volume. further,
Since the discharge side of the orifice is formed by a circular arc, the flow in the vicinity of the orifice flows outward along the circular arc portion on the discharge side. Therefore, the entire flow passing through the impeller changes from a perfect axial flow to a slightly oblique flow, and a pressure increasing action due to centrifugal force is applied, so that sufficient pressure characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along a plane including a rotation axis of a blower according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the air volume-pressure characteristics of the blower in comparison with a conventional blower.

FIG. 3 is a cross-sectional view taken along a plane including a rotation axis of a conventional blower.

[Explanation of symbols]

 4 Impeller 5 Orifice 5a Suction side arc part 5b Straight line 5c Discharge side arc part

Claims (2)

[Claims] 1. An axial flow impeller or a mixed flow impeller, and an orifice surrounding the outer periphery of the impeller, the cross section of the orifice having a partial or complete arc portion on the suction side, a straight line portion, and a discharge side arc portion. And a blower device in which the arc radius of the suction side arc portion is larger than the arc radius of the discharge side arc portion. 2. The blower according to claim 1, wherein the axial position of the trailing edge of the outermost periphery of the impeller is set within the range of the axial position of the arc portion on the discharge side.