CN106050700A - A silent fan structure - Google Patents

Abstract

The invention provides a silent fan structure which comprises a case, an air inlet, an air outlet, a volute, a wind wheel and a motor, wherein the size of the air outlet is less than or equal to that of the air inlet; the volute comprises an inlet base circle, a volute molded line, a diffuser and a volute tongue, wherein the diffuser is expanded along the rotation direction of the volute, and the expansion angle a of the diffuser is = 6-8 degrees; the diameter of the inlet base circle is D, the radius r of the volute tongue is = (0.025-0.05) D, and the distance k between the volute tongue and the inlet base circle is = (0.04-0.1) D. The air outlet speed is greater than or equal to the air inlet speed, and enough air inlet amount is supplied to the wind wheel, so that the noise generated by vacuum is avoided; the expansion angle of the diffuser can reduce the air flow speed of the air outlet and convert part of kinetic energy into a static pressure value; meanwhile, the frequency of the airflow entering the expander inlet from the wind wheel is different from the frequency of the airflow entering the expander outlet, so that the airflow is prevented from forming resonance in the expander and generating noise; when the r and k values are in the range, the noise of the fan is low and the fan efficiency is high.

Description

A silent fan structure

technical field

The invention relates to the technical field of centrifugal fan noise reduction, in particular to a silent centrifugal fan structure without sound-absorbing materials.

Background technique

The existing box-type centrifugal fan is mainly composed of a box body, a volute, a wind wheel, an air inlet, an air outlet and a motor. There is an air inlet and an air outlet; if there is no noise reduction device outside the volute, the noise will be relatively large, and the ability of the box to reduce noise is limited, so the noise is usually reduced by installing a muffler structure or filling the sound-absorbing material , this method makes the structure of the fan more complicated, or the cost is higher; on the other hand, due to the unreasonable structural design of the centrifugal fan, the efficiency of the fan is lower.

Contents of the invention

The object of the present invention is to provide a structure of a quiet fan, which does not need sound-absorbing materials, has good quiet effect, and has high fan efficiency.

To achieve the above object, the technical solution adopted in the present invention is:

A silent fan structure, comprising a case, an air inlet and an air outlet respectively arranged at both ends of the case, a volute arranged in the case, a wind wheel arranged in the volute, and a drive for driving the wind wheel motor, the size of the air outlet is d, the size of the air inlet is d1, d≤d1; the volute includes an inlet base circle, a volute profile, a diffuser and a volute tongue, and the diffuser follows As the volute expands in the direction of rotation, the expansion angle of the diffuser a=6°~8°; the diameter of the base circle of the inlet is D, and the radius of the volute tongue r=(0.025~0.05)D, so The distance k=(0.04~0.1)D between the volute tongue and the inlet base circle.

In a preferred manner, the radius of the volute tongue is r=0.05D, and the distance between the volute tongue and the inlet base circle is k=0.0625D.

In a preferred manner, the expansion angle of the diffuser is a=6°.

In a preferred manner, the material hardness of the blades of the wind wheel is less than that of the volute. Further, the blades of the wind wheel are made of aluminum, and the volute is made of galvanized sheet.

In a preferred manner, the motor is a direct-connected or external rotor motor.

The beneficial effects of the present invention are: 1. d≤d1, so that the air outlet wind speed is greater than or equal to the air inlet wind speed, and there is enough air intake to supply the wind wheel, avoiding the noise caused by vacuum; 2. The expansion angle of the diffuser can be reduced The airflow velocity at the air outlet converts part of the kinetic energy into a static pressure value; at the same time, the frequency of the airflow entering the expander inlet from the wind wheel is different from that of the expander entering the air outlet, so as to avoid the resonance of the airflow in the expander and generate noise; 3. Referring to the measured data in the table below, when the diameter of the base circle of the inlet is D, the radius of the volute tongue is r=(0.025~0.05)D, and the distance between the volute tongue and the base circle of the inlet is k=(0.04~0.1)D, the noise of the fan Smaller and more efficient fan.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of the fan structure of the present invention.

detailed description

The present invention will be further described below in conjunction with accompanying drawing:

A silent fan structure, comprising a case 1, an air inlet 11 and an air outlet 12 respectively arranged at both ends of the case 1, a volute 2 arranged in the case 1, and a wind wheel arranged in the volute 2 3. And a motor for driving the wind wheel 3 .

The size of the air outlet 12 is d, the size of the air inlet 11 is d1, d≤d1. The air outlet wind speed is greater than or equal to the air inlet wind speed, and sufficient air intake is supplied to the wind wheel 3 to avoid vacuum and noise.

The volute 2 includes an inlet base circle 21, a volute profile 22, a diffuser 23 and a volute tongue 24, the diffuser 23 expands along the direction of rotation of the volute 24, and the diffuser 23 The expansion angle a=6°~8°, preferably a=6°. The expansion angle of the diffuser 23 can reduce the airflow velocity at the air outlet 11, and convert part of the kinetic energy into a static pressure value; at the same time, the frequency of the airflow entering the inlet of the expander 23 from the wind wheel 3 is different from the frequency at which the expander 23 enters the air outlet 12, Avoid air flow from forming resonance in the expander 23 and generating noise.

The diameter of the inlet base circle 21 is D, the radius of the volute tongue 24 is r=(0.025~0.05)D, and the distance between the volute tongue 24 and the inlet base circle 21 is k=(0.04~0.1)D; preferably The method is: the radius of the volute tongue 24 is r=0.05D, and the distance between the volute tongue 24 and the inlet base circle 21 is k=0.0625D. Refer to the measured data in the table below, when the r and k values are within this range, the noise of the fan is small and the efficiency of the fan is high.

The blade material hardness of the wind wheel 3 is less than that of the volute 2; further, the blades of the wind wheel 3 are made of aluminum, and the volute 3 is galvanized. Due to the different materials of the two, the impact frequency of the airflow on the blade and the volute 3 is different, and no resonance effect will be generated.

The motor is a direct-connected or external rotor motor. Secondary noise generated by multiple connected parts is reduced.

The above description does not limit the technical scope of the present invention in any way, and any modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solutions of the present invention.

Claims (6)

1. A silent blower fan structure, comprising a casing, an air inlet and an air outlet respectively arranged at two ends of the casing, a volute arranged in the casing, a wind wheel arranged in the volute, and driving the The motor of the wind wheel is characterized in that: the size of the air outlet is d, the size of the air inlet is d1, d≤d1; the volute includes an inlet base circle, a volute profile, a diffuser and a volute tongue, The diffuser expands along the rotating direction of the volute, and the expansion angle of the diffuser is a=6°~8°; the diameter of the base circle of the inlet is D, and the volute tongue radius r=(0.025 ~0.05) D, the distance between the volute tongue and the inlet base circle k=(0.04~0.1) D. 2 . The silent fan structure according to claim 1 , wherein the radius of the volute tongue is r=0.05D, and the distance between the volute tongue and the inlet base circle is k=0.0625D. 3. The silent blower structure according to claim 1 or 2, characterized in that the expansion angle of the diffuser is a=6°. 4 . The silent fan structure according to claim 1 or 2 , wherein the material hardness of the blades of the wind wheel is less than that of the volute. 5 . 5 . The silent fan structure according to claim 4 , wherein the blades of the wind wheel are made of aluminum, and the volute is made of galvanized sheet. 6 . 6. The structure of a silent fan according to claim 1 or 2, characterized in that the motor is a direct-connected or external rotor motor.