JPS5939196Y2 - Impeller for cross flow blower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates in particular to noise prevention means for a cross-flow blower.

Conventional cross-flow blowers are known to be capable of achieving considerably greater pressures, flow rates, and efficiencies than other blowers.

However, the extremely high-velocity fluctuating flow near the vortex center caused by the potential flow and the wing wake interferes with the casing tongue on one side of the inflow section, resulting in considerably high rotational noise and vortex noise with a wide frequency distribution. Noise is generated.

For this reason, it has been considered to increase the gap between the casing tongue and the impeller to reduce noise generation, but this has the drawback of adversely affecting performance.

In addition, as shown in Fig. 3, a proposal was made to prevent noise by making the casing tongue 50 slightly inclined with respect to the axis of the impeller 1 to continuously shift the phase of the rotation sound.
28), but in this case, since the tongue portion 50 is linear, the gap W between the tongue portion 50 and the impeller 1 is the center portion W.
1 is narrow, and both ends W2 are wide, making it impossible to make effective use of the entire length of the impeller, resulting in decreased performance.

This becomes more noticeable as the overall length of the impeller 1 increases.

In order to solve the above problem, the present invention is characterized by using an impeller that is twisted uniformly about the axis, and the conventional one in which the tongue of the casing is parallel to the blade plate can be used to its advantage and reduces noise. The purpose of the present invention is to provide a cross-flow blower that prevents the occurrence of such problems, has excellent performance, and is easy to manufacture.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIGS. 1 and 2 show a casing 5 extending in the longitudinal direction of the impeller 1 at a suitable location around the impeller 10, and a casing 5 whose tip is curved in an arc whose tip meets the tangential direction of the impeller. 5 shows a cross-flow impeller surrounded by a parallel casing 6 and an edge tongue 50 of the casing 5.

The casing 5 has a tongue portion 50 at the tip thereof extending in a direction eccentric to the radial direction of the impeller 1 by a predetermined degree to form an air inflow lower and an air outlet 8 between the casing 5 and the impeller 1 .

The impeller 1 has a plurality of mounting grooves 20, 20° 30 drilled at equal intervals on both ends and the circumference of the intermediate disk 2.2.3, and a predetermined length is formed into each corresponding mounting groove 20.30. It is formed in a cylindrical shape so as to pass through an integral vane plate 4 of the impeller 1, and is characterized in that each vane plate 4 is inclined at an appropriate angle in the same direction with respect to the axis of the impeller 1.

To form the impeller 1, attach the mounting grooves 20° 20.30 of each isk 2, 2.3 arranged in parallel at a predetermined interval.
After inserting and installing the straight wing plate 4, the disks 2 at both ends
, 2゛ are twisted and rotated in opposite directions.

The twist angle depends on the impeller dimensions and operating conditions.

For example, impeller length 47577Z77Z diameter 12677
277Z, number of blades per second: 33, impeller rotation speed: 160O
rpm, one end of the impeller is fixed and the other end is twisted to rotate the impeller to such an extent that the blades are tilted by 2 to r. In this state, the impeller 1 is subjected to thermoplastic processing, for example, by heating and then cooling. It can be easily formed by simply fixing it.

Alternatively, each vane 4 may be formed by twisting it at a predetermined angle in advance - the vane 4 can be formed by twisting each vane 4 into the mounting groove 20 of each disk 2, 2.3. 20.30
It can also be formed by penetrating it and attaching it.

The tongue portion 50 of the casing 5 has a linear shape parallel to the axis of the impeller 1, and the gap between the tongue portion 50 and the impeller 1 has a uniform width over the entire length.

As described above, in the present invention, each blade plate 4 is inclined at a predetermined angle in the same direction with respect to the axis of the impeller 1, so that, despite the simple structure, the fluctuating flow generated by the blade wake is caused by the casing tongue. This can be canceled out by continuously shifting the phase of the rotational noise generated due to interference, preventing noise generation and realizing quiet operation.

In addition, the gap between the casing tongue 50 and the impeller 1 has a uniform width over the entire length, and the gap between the impeller and the tongue is uniform as in the conventional case where the tongue is tilted with respect to the axis of the impeller. The gap between the two is not uniform and there is no reduction in efficiency.

However, the impeller 1 can be easily made by twisting the entire blade and tilting the two blades at the same time.

Furthermore, it has excellent practical effects, such as being able to use the existing casing just by replacing the impeller.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view showing the main parts, Figure 2 is Figure 1 -
3 is a cross-sectional view of the conventional example. 1... Impeller, 2... Discs at both ends, 3... Intermediate disk, 4... Wing plate.

Claims (1)

[Scope of utility model registration request] In a cylindrical transverse flow impeller whose axial length is sufficiently long relative to the diameter and is freely rotatable opposite the air inlet of the casing, the tip of the tongue of the casing is in a straight line parallel to the axis. It is formed into a shape and placed close to the circumferential surface of the impeller,
The impeller has a plurality of thin and narrow long vanes arranged at equal intervals on the circumference of the disk at both ends and the middle disk, tilted at a predetermined angle in the same direction with respect to the axis. A cross-flow blower characterized in that a gap between the section and the section is uniformly formed over the entire length.