JP2007092570A - Turbo fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To silence an air flow from the suction to the discharge. <P>SOLUTION: A turbo fan comprises a casing, a multiblade impeller rotatably pivoted within the casing, an impeller boss that is opposite to a suction port center section of the casing at the inner side of the multiblade impeller, and a drive motor installed in the impeller boss. An impeller boss outer peripheral surface continuous from a head part periphery which faces the suction port center section of the casing to an impeller holding substrate inner periphery has a circular arc cross-section surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an improvement in quietness of a turbofan, particularly a thin turbofan.

(Japanese Unexamined Patent Application Publication No. 2004-239188)

Improvements related to the quietness of the turbofan 1 have been diversified with the expansion of applications involving downsizing and thinning, and many measures have been proposed in addition to the well-known prior art documents. In reality, there are many improvements related to multi-blade impellers, which are noise generation sources during operation, for blade shape setting and blade arrangement based on fluid dynamics.

And as a structure of a multiblade impeller, in order to hold | maintain many blades 4 arranged in a cylinder as a rotary body, the impeller boss 6 linked with the axis | shaft 3-1 is provided, but the impeller boss 6 seen as a well-known structure is as follows. As illustrated in FIG. 4, a portion that is formed in a cup shape to accommodate the drive motor therein and communicates with the top portion that holds the rotor 3 and the inner peripheral edge of the impeller holding substrate 5 has a cylindrical shape 6. -2.

The operation sound of the turbo fan 1 is caused by the impeller 4 of the impeller as described above, and noise related to the impeller boss 6 due to the disturbance of the intake air is added, and noise propagation from around the impeller boss 6 is an improvement issue. There is no change, and it can be said that the improvement of the rigidity of the impeller boss 6 is an issue to be studied, and the smoothness of the air flow during intake is also to be improved. FIG. 3 shows a state of the wind flow f in the configuration of the turbofan 1 according to the prior art corresponding to the example of FIG. 4 described above, and a sudden change in the flow direction at the portion where the impeller boss 6 communicates with the holding substrate. This shows that turbulent flow f2 is generated.

Although the conventional configuration as described above has achieved the corresponding effect, the need for practical improvement does not stop, and even with small improvements, it is desirable to realize further calming by accumulation. The fact is that there is no change in being.

The present invention includes a casing 7, a multi-blade impeller (4) rotatably supported in the casing 7, an impeller boss 6 formed inside the multi-blade impeller (4), and the impeller boss. 6 has a drive motor built in, sucks air from a suction port formed in one side wall of the casing 7, and applies centrifugal force to the intake air by the rotation of the multi-blade impeller (4), The turbofan 1 that discharges high-pressure air from a discharge port formed in a part of the outer peripheral surface of the casing 7, and the inside of the impeller holding substrate 5 from the head periphery 6-1 that faces the suction port center of the casing 7. The impeller boss outer peripheral surface 6-2 that communicates with the periphery is configured to have a circular arc cross section.

The turbofan 1 according to the present invention achieves noise suppression by smoothing the flow of air from the intake to the exhaust by the configuration as described above.

A turbofan 1 according to the present invention includes a casing 7, a multi-blade impeller (4) rotatably supported in the casing 7, and an impeller boss formed inside the multi-blade impeller (4). 6 and a drive motor mounted in the impeller boss 6, sucks air from a suction port formed in one side wall of the casing 7, and converts the air into intake air by the rotation of the multi-blade impeller (4). A centrifugal force is applied to discharge high pressure air from a discharge port formed in a part of the outer peripheral surface of the casing 7, and an impeller holding substrate is formed from a head peripheral edge 6-1 facing the central portion of the suction port of the casing 7. The impeller boss outer peripheral surface 6-2 that communicates with the inner peripheral edge of 5 is formed in a circular arc shape in cross section.

FIG. 1 shows an example of a turbofan 1 according to the present invention, in which air flowing from a suction port flows in an axial direction along the impeller boss outer peripheral surface 6-2 and is forced to change direction at a communication portion with the impeller holding substrate 5. As shown in FIG. 2, as a means for suppressing the occurrence of turbulence, the shape of the outer peripheral surface extending from the top peripheral edge 6-1 of the impeller boss to the root portion of the holding substrate 5 is an arc of a cross section. is there.

The shape of the impeller boss outer peripheral surface 6-2 according to the present invention described above can be applied not only to a turbo fan but also to a general-purpose centrifugal fan.

The turbofan 1 according to the present invention is widely used as a configuration that is effective for quietness without stopping while responding to the needs for downsizing and thinning.

It is principal part sectional drawing of the example of the turbofan which concerns on this invention. FIG. 2 is a half-sectional perspective view showing the wind flow of the example of the present invention shown in FIG. 1. FIG. 5 is a half-sectional perspective view showing a state of wind flow in the example of the prior art shown in FIG. 4. It is principal part sectional drawing of the example of the turbofan used conventionally.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turbofan 2 Stator of drive motor 3 Rotor of drive motor 3-1 Rotating shaft 4 Impeller 5 Impeller holding board 5-1 Inner peripheral edge of impeller holding board 6 Imperos 6-1 Top peripheral edge of Imperas 6-2 Outer periphery of Imperas Surface 7 Turbofan outer casing (partial display)

Claims (1)

  A casing, a multi-blade impeller rotatably supported inside the casing, an impeller boss formed inside the multi-blade impeller, and a drive motor installed in the impeller boss, Air is sucked from a suction port formed on one side wall, centrifugal force is applied to the suction air by the rotation of the multi-blade impeller, and high-pressure air is discharged from a discharge port formed on a part of the outer peripheral surface of the casing. In the turbofan, the impeller boss outer peripheral surface communicating with the impeller holding substrate inner peripheral edge from the peripheral edge of the head facing the suction port central portion of the casing has an arcuate cross section.

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