JPS63170589A - Impeller - Google Patents

Abstract

PURPOSE:To reduce noise by providing vanes at uneven spacings on the periphery of a hub in appro. cylindrical form, wherein the vanes shall have different projected figures on a plane which is perpendicular to the rotary shaft. CONSTITUTION:Vanes 12-16 having different projected figures on a plane, which is perpendicular to the rotary shaft, a provided on a hub 11 in approx. cylindrical form. They are arranged on the periphery of the hub in such a way that they are not overlapped with one another, and the hub 11 shall be provided with notches 17 where the vanes 12-16 are overlapped with the hub 11. Thus the vanes are arranged around the hub at uneven pitches to suppress Nz sound, and at the same time, sufficient vane area is obtained, which ensures high performance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an axial flow or mixed flow impeller widely used in air conditioning equipment.

2. Description of the Related Art As shown in FIG. 3, a conventional impeller of this type has a structure in which a plurality of vanes 2 of the same shape are provided on the peripheral wall surface of a substantially truncated conical hub 1, and a suitable casing such as an orifice or a casing is provided. In combination with this, the air blowing effect was achieved by rotating it. In addition, the blades do not overlap each other, and cutouts 3 are provided in the hub where the hub and blades overlap, allowing integral molding of the impeller.

On the other hand, when blades are provided at equal intervals on the hub, a noticeable blade rotation sound (NZ sound) is generated due to interference between the blades and surrounding fixed objects, so as shown in Figure 4, Unequal pitch impellers were also made with blades 4 spaced apart.

Problems to be Solved by the Invention However, in the above configuration, in order to arrange the blades at unequal intervals around the hub and to eliminate mutual overlap of the blades, it is necessary to reduce the projected area of the blades. In other words, when realizing an unevenly spaced blade arrangement using a blade shape that maximizes the projected area of the blades with an evenly spaced blade arrangement, unless the number of blades is reduced, there will be parts where the blades overlap, resulting in integral molding. becomes impossible. On the other hand, if the number of blades is reduced, integral molding is possible, but there is a problem in that it leads to a decrease in performance.

The present invention has been made to solve these conventional problems, and aims to provide an impeller that can reduce N2 sound without deteriorating performance and that can be integrally molded.

Means for Solving the Problems In order to solve the above problems, the impeller of the present invention has a plurality of blades provided at unequal intervals on the peripheral wall surface of a substantially cylindrical or substantially truncated conical hub, and a plurality of blades arranged at irregular intervals. The blades have a mixture of blades with different projection plane shapes on a plane perpendicular to the rotation axis, and the projection plane shapes of each blade do not overlap each other and are formed so as to almost cover the entire projection plane, and the projection of the blades is A notch is provided in the hub at a portion where the surface shape and the hub overlap.

According to the above-described configuration, the present invention has several types of blades with different projected surface shapes arranged on the peripheral wall surface of the hub, so that the projected area and shape of the blades can be arbitrarily selected. It is possible to arrange the blades at unequal intervals while maintaining the maximum projected area, and to eliminate overlapping blades. Therefore, it is possible to obtain an impeller shape that not only ensures and maintains sufficient aerodynamic performance but also can be integrally molded.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In FIGS. 1 and 2, 11 is a hub and 12 to 16 are blades. The projection plane shapes of the five blades 12 to 16 are all approximately fan-shaped, but the projection plane shapes are different from each other, and the central angle α of the approximately fan-shape is approximately 80',
65°, 70'.

The angles are 80° and 85°. Here, since the total center angle is approximately 360°, by arranging all the blades on the peripheral wall of the hub so that they do not overlap each other, the maximum blade area that covers almost 100% of the projection plane can be achieved. can get. Furthermore, a notch 17 is provided in the hub at a portion where the blades 12 to 16 and the hub 11 overlap. In addition, since the central angles of blades 12 to 16 are the above values, the installation intervals of each blade are 62.5°, 67.5°, and 7°.
5°.

The blades are arranged at a perfect pitch of 8265° and 72.5'.

In the above configuration, the blade area is approximately the maximum area without overlapping each other, and sufficient air blowing performance is obtained.In addition, since the hub is provided with a notch 17, integral molding is also possible. It has become. moreover,
Since the pitches of the blades are unequal, interference between the blades and surrounding fixed objects occurs at unequal intervals, which has the effect of suppressing the generation of N2 sound.

Effects of the Invention As described above, the impeller of the present invention provides the following effects.

(1) Since the blades are arranged around the hub at uneven pitches, N2 noise is suppressed and a low-noise impeller can be obtained.

(2) Each blade has a different shape and is formed so that it almost covers the entire projected surface of the impeller and does not overlap with each other, so the blade area is sufficiently large.
Not only does it provide high performance, but it also allows for integral molding by providing a notch in the hub.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an impeller according to an embodiment of the present invention, FIG. 2 is a perspective view of the same impeller, FIG. 3 is a plan view of a conventional impeller, and FIG. 4 is a plan view of another conventional impeller. FIG. 11...Hub, 12.13.14.15.16
...Feather, 17...Notch. Name of agent: Patent attorney Toshio Nakao and 1 other person

Claims (1)

[Claims] A plurality of blades are provided at unequal intervals on the peripheral wall surface of a substantially cylindrical or substantially truncated conical hub, and the plurality of blades include a mixture of blades having different projected plane shapes on a plane perpendicular to the rotation axis, and The projected surface shapes of each blade do not overlap with each other,
The impeller is formed to substantially cover the entire projection surface, and has a notch provided in the hub at a portion where the projection surface shape of the blade and the hub overlap.