Centrifugal fan with low noise

Abstract

A centrifugal fan with low noise includes a housing, a fan wheel and a recess unit. The fan wheel has a hub and a plurality of fan blade extending outward from the hub radially. The housing has a chamber therein to receive the fan wheel and has a recess unit at the surface thereof. The recess unit is composed of a projection part and a recess part for reducing noise transmission greatly.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention is related to a centrifugal fan with low noise and particularly to a centrifugal fan capable of attenuating noise. [0003] 2. Brief Description of the Related Art [0004] Application of the computer industry is getting popular along with the information technology being highly developed. Further, due to network being developed prosperously with a great deal of network transmissions and data processing, more computer equipment are needed for offering sufficient operation and processing capability. [0005] Owing to manufacturing process of integrated circuit being improved, fabrication of integrated circuit is getting delicate and complicated. Various computer equipments provide more powerful functions. But, the complicated circuit leads to huge power consumption and the power consumption results in a serious problem because of temperature of the equipment rising caused by the power consumption. [00...

AI Technical Summary

Benefits of technology

[0013] A main object of the present invention is to provide a centrifugal fan with low noise in which the housing has a recess unit at the surface thereof to lessen transmission and creation of noise.

[0014] Another object of the present invention is to provide a centrifugal fan with low noise in which the recess unit on the surface of the housing is formed with at least a projection part and a recess part for intensifying strength of the surface of the housing.

[0015] In order to achieve the preceding object, a centrifugal fan with low noise according to the present invention includes a housing and a fan wheel. The housing forms a chamber inside to receive the fan wheel and has a recess unit at the surface thereof to decrease noise being transmitted outward.

Problems solved by technology

Owing to manufacturing process of integrated circuit being improved, fabrication of integrated circuit is getting delicate and complicated.

But, the complicated circuit leads to huge power consumption and the power consumption results in a serious problem because of temperature of the equipment rising caused by the power consumption.

Because heat congregating in the equipment and being incapable of being dissipated outward properly, the electronic components inside are unable to work normally and the entire equipment will be influenced under this circumference.

As a result, the computer system will be shut down unexpectedly.

Further, flow field inside the centrifugal fan is quite complicated and fluid flows radially along with the fan wheel such that it produces phenomena such as recirculation, reversed flow and separation to complicate flow field in the fan wheel and produce high noise decibel.

However, a problem of the conventional centrifugal fan in practice resides in that the housing 11 is flat at the surface thereof with strengthen ribs 1122 being added at the reinforced position only such that the fluid accelerates with increasing flow energy after passing through the fan blades to impact the housing 11 while the fluid is entering the housing 11 via the first inlet 1111 and the second inlet 1121 and shooting outward speedily due to the fan blades 132 rotating and it results in vibration and louder noise because of the flat surface of the housing with too wick structural tension.

In addition, rotational noise with various frequencies occur during the fan is in operation and the noise with the frequencies especially with the narrow band frequency easily transmits outward to results in the user having uncomfortable feeling caused by the narrow band noise being sharp to the hearing sense of the user.

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