Centrifugal fan

Abstract

The invention relates to a centrifugal fan, which comprises a hub part and an impeller. The hub part is used to fix the centrifugal fan on a rotary shaft. The impeller consists of a plurality of vanes which are fixedly arranged on the outer edge of the hub part. The paraxial sides of the vanes are in a backward inclined vane structure while the abaxial sides thereof are in a forward vane structure. The vanes are further provided with chamfered structures on the paraxial sides to enlarge an air inlet of the fan. The opposite sides of the air inlets of the vanes further comprise protruding parts extending along the direction of the rotary shaft to increase the air flow through a fan motor. The centrifugal fan further comprises an anti-pressure relieving cover closed to the air inlet of the impeller to prevent axial flow of gas sucked so as to improve the pressure relieving condition.

Description

[0001] This application is a divisional application of the invention patent application with the application number 200310103883.0, the application date being November 18, 2003, and the invention name being "centrifugal fan". technical field [0002] The present invention relates to a fan, in particular to a centrifugal fan. Background technique [0003] Existing centrifugal fans, such as the centrifugal fan disclosed in U.S. Patent No. 5,813,831, mainly consist of a hub (not shown in the figure) and a plurality of blades 11, such as Figure 1a and Figure 1b shown. Used to fix the fan on the rotating shaft (not shown in the figure) to make the fan rotate; the proximal ends of the blades 11 are respectively fixed on the outer edge of the hub, and their arrangement is divided into forward-leaning blades (such as Figure 1a shown) and backward leaflets (such as Figure 1b shown). [0004] However, the above-mentioned centrifugal fan still has many shortcomings that must be i...

AI Technical Summary

Problems solved by technology

[0004] However, there are still many shortcomings in the above-mentioned centrifugal fans that must be improved.

For example, under the condition of the same fan speed, for the fan with backward inclined blades, although the fan with forward inclined blades can output higher wind pressure and provide better heat dissipation effect, it also increases the load on the motor a lot, so it is desirable to There is a technical bottleneck that is difficult to break through when increasing the speed of the forward-leaning fan

However, because the cooling effect of the backward-leaning fan is worse than that of the forward-leaning fan at the same speed, the speed must be increased to achieve the same heat dissipation effect as the forward-leaning fan.

However, due to the increase of the speed, the noise generated by it is also relatively increased.

[0005] In addition, there is a certain gap between the fan blades and the fan frame in the flow channel surrounded by the fan blades and the fan frame. If the gap is too small, the blades are likely to be damaged due to collisions with the fan frame due to vibration and other factors.

If the gap is too large, the inhaled gas will have space to flow axially, and pressure relief will occur, which will reduce the heat dissipation effect and generate greater noise

[0006] Existing centrifugal fans often reduce the area of ​​the air inlet in order to increase the work area of ​​the blade, that is, the width of both ends of the blade is equal, so when the air inlet volume is reduced, the heat dissipation effect is naturally relatively reduced

[0007] In addition, the existing fan design only pays attention to the heat dissipation of the system, and does not pay attention to the high temperature of the fan motor itself due to high-speed operation, so it is easy to stop the operation due to the high temperature of the fan motor itself or self-protection

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