LOW-NOISE BLADELESS FAN

Abstract

A low-noise bladeless fan includes a base, a nozzle at the top of the base and noise-reduction components located within the base. The noise-reduction components include a first noise-reduction component, a second noise-reduction component and a third noise-reduction component. The first noise-reduction component is located at an interface between air outlets and an internal passage for airflow reduces noise by isolating, obstructing and separating noise created inside the outer casing. The second noise-reduction component is disposed within an impeller fixture reduces noise by absorbing noise created inside the outer casing. Through-holes are disposed in the bottom of the outer casing act as the third noise-reduction component and also reduce noise. The arrangement of noise-reduction components can reduce noise created in the fan, thereby cooling users with natural and soft wind.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to Chinese Patent Application No. 201110234196.7, filed on Aug. 16, 2011, which is owned by the instant application and the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to bladeless fan, and particularly relates to a low-noise bladeless fan.

BACKGROUND OF THE INVENTION

Traditional fans are operated in such a way: an electric motor drives blades to rotate so as to create wind and to speed up air flow in the surrounding environment, for cooling and heat-relieving and ventilation. But such kind of traditional fans are prone to danger (e.g. some kids may put their fingers into a fan when they are not carefully watched and thereby would be hurt by the blades), including some hidden dangers, and are not easy to clean.

A type of bladeless fan device for creating airflow is disclosed in an patent application, publication number CN10142478A, which eliminates the above deficiencies in the traditional fans. Yet to meet the designing demand of bladeless fan, the designer would design some abrupt changes in shapes or bosses at the connecting portion between the base for housing an impeller and a nozzle, as a result, when flowing into the internal passage for airflow in the nozzle through the air inlets of the base, the airflow will pass by the abrupt changes or the bosses and then the resistance increases. And noise will be caused at the interface between the air outlets and the internal passage for airflow under the action of air shear forces and other acting forces. In addition, about 90% of the interior space of the base is occupied by the impeller assembled; so there is only about 10% of the interior space of the base available for airflow that flows into the outer casing. It is to say, the space provided by the duct for the airflow is the gap between the impeller and the outer casing. When airflow flows into the air ducts, it will give rise to loud whistlers due to abrupt change of its flowing passage. Meanwhile the impeller will also create noise during its operation. The air inlets of the base, which are in communication with the outside, are prone to being influenced from the external environment. Dust, oil stain and the like from the external environment are likely to come inside the fan through the air inlets during the operation of the fan, which also cause more noise.

Further, bladeless fan devices are also disclosed in other patent reference documents, such as CN201568337U, KR100985378, HK1146191; but no solutions are raised to efficiently reduce the noise created in the bladeless fan.

SUMMARY OF THE INVENTION

In order to make up the deficiencies that rotating blades may hurt people and to lower the noise from the fan, the present invention provides a safe low-noise blades fan.

In order to have the above technical problem addressed, the present invention provides the following technical solutions:

A low-noise bladeless fan comprises a base provided with an impeller fixture and a nozzle located on the top of the base. The nozzle comprises an internal passage for receiving airflow flowing through air outlets and an air exhaust port. The internal passage is annular and forms a continuous loop or pipe within the nozzle. The air exhaust port comprises a conical region tapered to an exit. As a component which is internally hollow and having through-holes in its outer wall thereof, the impeller fixture contiguously or alternately surrounds the impeller and is in annular shape or other shape. There are noise-reduction components are provided within the base, including a first noise-reduction component and a second noise-reduction component. The first noise-reduction component is set on the inner wall of the outer casing, at the interface between the air outlets and the internal passage for airflow, and in the space between the outer side of the impeller and the inner wall of the outer casing. The first noise-reduction component is used for isolating, obstructing and separating noise created in the outer casing during operation of the fan. The second noise-reduction component is set inside the impeller fixture for absorbing noise generated in the outer casing, with its position and shape fitting to the position and shape of the impeller fixture.

Preferably, the nozzle extends substantially orthogonally about the axis to define an opening. The opening has a shape which is circular in an inner track thereof and egg-shaped in an outer track thereof.

Preferably, the first noise-reduction component is trapezoidally distributed from the outer casing to the air outlets along the inner wall of the outer casing, with the sectional area in the vicinity of the air outlets smaller than the sectional area in the vicinity of the air inlets. There is a gap between the first noise-reduction component and the impeller.

Preferably, the second noise-reduction component is entirely or partially filled inside the impeller fixture.

Preferably, the first noise-reduction component is made of steel plates, lead plates, brick walls or other materials of higher density.

Preferably, the second noise-reduction component is made of slag wool, blankets or other porous sound absorbing materials.

Preferably, the first noise-reduction component is made of one of the materials or any combination of several of them.

Preferably, the second noise-reduction component is made of one of the materials or any combination of several of them.

Preferably, the noise-reduction components further include a third noise-reduction component which is through-holes disposed in the bottom of the outer casing. The third noise-reduction component is effective on enlarging the airflow into the fan and for reducing noise.

The present invention relates to a low-noise bladeless fan comprising a first noise-reduction component, a second noise-reduction component and a third-noise reduction component. The first noise-reduction component is located at the interface between the air outlets and the internal passage for airflow can reduce noise by isolating, obstructing and separating noise created in the outer casing during the operation of the fan. The second noise-reduction component disposed within the impeller fixture can reduce noise by absorbing noise generated in the outer casing. The through-holes disposed in the bottom of the outer casing act as the third noise-reduction component and also can reduce noise. Therefore, compared with the prior art, the present invention becomes safer by getting rid of the deficiency that people may be hurt by rotating blades and can remarkably reduce the noise created in the fan.

Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating the principles of the invention by way of example only.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of the invention described above, together with further advantages, may be better understood by referring to the following description taken in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

FIG. 1 is a side view of a low-noise bladeless fan of the present invention.

FIG. 2 is a structural schematic view of the low-noise bladeless fan of the present invention along an A-A cross-section.

FIG. 3 is a partial schematic view of the low-noise bladeless fan of the present invention.

DESCRIPTION OF THE INVENTION

FIG. 1 shows a side view of a low-noise bladeless fan 10 including a base 11 and a nozzle 12.

As shown in FIG. 2, the low-noise bladeless fan 10 comprises the nozzle 12 located at the top of the base 11, and noise-reduction components 13 located within the base 11.

As a major mounting assembly of the low-noise bladeless fan, the base 11 can have an arced shape, a cylindrical shape, a cuboid shape or other shapes.

The base 11 comprises an outer casing 111, air inlets 112, air outlets 113, air ducts 114 between the air inlets 112 and the air outlets 113, as well as an impeller 115 and an impeller fixture 116 accommodated in the outer casing 111.

The outer casing 111 is a casing body with an opening at one end thereof, the opening being in communication with the nozzle 12. The outer casing 111 has a shape designed based on actual design demand and not confined to the present embodiment.

The air inlets 112 are a plurality of through-holes disposed on a side face of the base 11 and run through the side wall of the outer casing 111, for communicating airflows inside and outside the outer casing 111. The air inlets 112 in the present embodiment are uniformly distributed on one side of the outer casing 111. Of course, the air inlets 112 also can be distributed all over the entire side wall or the other side walls of the outer casing 111. The detailed positions and distribution manners not confined to the present embodiment.

The air outlets 113 are located at the opening of the outer casing 111 and are in communication with the nozzle 12 for delivering airflow to the nozzle 12.

The air ducts 114 are located between the air inlets 112 and the air outlets 113 to provide channels for the airflow that flows from the air inlets 112 into the outer casing 111. During operation, the airflow flows into the outer casing 111 from the air inlets 112 and flows along the air ducts 114 to the air outlets 113.

The impeller 115 located in the air ducts 114 is fixed inside the outer casing 111 by the impeller fixture 116, for increasing pressure of air that flows from the air inlets 111 and delivering pressurized air to the air outlets 113.

The impeller fixture 116 is an internally hollow component with through-holes on its outer wall and encircles the impeller 115 contiguously or alternately. The shape of the impeller fixture 116 could be annular shape or other shape, and in this preferable embodiment it is annular shape.

As shown in FIG. 3, the nozzle 12 comprises an internal passage 121 for receiving the airflow from the air outlets 113 and an air exhaust port 122 where the airflow is emitted. The nozzle 12 extends substantially orthogonally or circumferentially about the axis X to define an opening 123 which could be in many shapes, such as a circular shape, an elliptical shape, a rounded rectangular shape, a partially annular shape, or other shapes. In the present embodiment, the inner track of the opening 123 is circular and the outer track is egg-shaped.

The internal passage 121 is annular and forms a continuous loop or pipe that located inside the nozzle 12.

The air exhaust port 122 comprises a conical region 1222 tapered to an exit 1221.

Air from outside the fan device is drawn by the airflow emitted from the air exhaust port 122 through the opening 123.

During the operation of the low-noise bladeless fan of the present embodiment, airflow flows into the outer casing 111 from the air inlets 112 and pass by the air ducts 114. After being pressurized by the impeller 115, the airflow flows from the air outlets 113 into the internal passage 121.

Due to the designing demand of the low-noise bladeless fan, noise will be created when airflow flows into the internal passage 121 from the air inlets 113. As a result, there would be a first noise source 100 defined at the interface between the air outlets 113 and the internal passage 121. The impeller 115 as shown in the figures occupies about 90% of the space of the base 11, hence there would be only 10% of the space left for the airflow that flows into the outer casing 111; it is to say, the space in the air duct 114 is the space in the casing 111 subtract the volume of the impeller 115. When the airflow flows into the air ducts 114 from the space encircled by the outer casing 111, large noise will be created, plus, the impeller 115 would also create some noise; herein there would be a second noise source 101 defined. In order to reduce the noise, in the present embodiment, noise-reduction components 13 are set in the base 11.

The noise-reduction components 13 comprise a first noise-reduction component 131, and a second noise reduction component 132.

The first noise-reduction component 131 is disposed on the inner wall of the outer casing 111, and located at the interface between the air outlets 113 and the internal passage 121, and in the space between the outer side of the impeller 115 and the inner wall of the outer casing 111. The first noise-reduction component 131 is used for isolating, obstructing and separating the noise created in the outer casing 111 during the operation of the fan. The first noise-reduction component 131 is made of a material which reduces transmission sound energy from an incident sound source by reflecting the incident sound. The material is heavy and compact, free of pores or gaps and of a higher density (such as, steel plates, lead plates, brick walls or other materials of a higher density). The first noise-reduction component 131 mainly functions to obstruct noise from being delivered from the inside of the outer casing 111 to the space outside the outer casing 111 by reflecting the noise created in the space formed between the air ducts 114 and the air outlets 113 within the outer casing 111 (such as the noise created during operation of the impeller 115, the noise caused by the abrupt changes in the shape of the flow passage when airflow flows past the outer side of the impeller 115 or the connection portion between the outer casing 111 and the nozzle 12). Thereby the first noise reduction component prevents the inference of the noise. As can be seen from the above noise-reduction principle of the first noise-reduction component 131, the effect of noise reduction by using the first noise-reduction component 131 which is made from a soundproof material or of a sound proof configuration is much better than the effect of noise reduction by absorbing sound. The first noise-reduction component 131 in the present embodiment is disposed between the outer side of the impeller 115 and the inner wall of the outer casing 111, at the connection portion between the outer casing 111 and the nozzle 12, with its shape matching the shape of the outer casing 111. The first noise-reduction component 131 is trapezoidally distributed from the outer casing 111 to the air outlets 113 along the inner wall of the outer casing 111, with the sectional area in the vicinity of the air outlets 113 smaller than the sectional area in the vicinity of the air inlets 112. There is a gap between the noise-reduction component 131 and the impeller 115. Preferably, the air ducts 114 are partially filled with the first noise-reduction component in the present embodiment.

The second noise-reduction component 132 is disposed within the impeller fixture 116 which is internally hollow and provided with through-holes in the outer wall thereof, with its position and shape matching the position and the shape of the impeller fixture 116. The second noise-reduction component 132 is used for absorbing noise created in the outer casing 111. The second noise-reduction component 132 is made from a material which reduces transmission of the sound energy of an incident sound source by absorbing the incident sound. The material comprises a large quantity of porous sound-absorbing materials that are interpenetrating and having micro-porous from the exterior to the interior (such as: slag wool, blankets, or other porous sound-absorbing materials). The second noise-reduction component 132 mainly functions to absorb the noise created in the space formed by the air ducts 114 and the air inlets 112 within the outer casing 111 (such as, the noise created during the operation of the impeller 115, the noise caused by the changes in the shape of the circulation space when airflow flows past the outer side of the impeller 115 by the air inlets 112 or the airflow flows into the narrow air ducts 114 from a larger space in the lower portion of the base 11). The incidence of sound waves to the surface of the second noise-reduction component 132 causes vibration of air inside the micropores of the second noise-reduction component 132. Because of the friction resistance and the viscous resistance of air as well as thermal conduction, the second noise-reduction component 132 could convert a substantial portion of sound energy into heat. Then sound is absorbed, and the noise transfer from the inside of the outer casing 111 to its outside is obstructed. The inside of the impeller fixture 116 is partially or entirely filled with the second noise-reduction component 132. Preferably, the second noise-reduction component 132 in the present embodiment is disposed within the hollow impeller fixture 116 and has the hollow impeller fixture 116 entirely filled, with its shape matching the shape of the impeller fixture 116.

As the first noise source 100 is located at the interface between the air outlets 113 and the internal passage 121, if a porous second noise-reduction component 132 is used at the first noise source 100, the quickly flowing airflow at the interface can easily induce the second noise-reduction component 132 to block the impeller. In addition, some oil and dust would enter the fan from the air inlets 112; the porous second noise-reduction component 132 which sucks oil and dust and so on becomes unable to reduce noise. As a result, in the present embodiment, the first noise-reduction component 131 which is rigid and firm is used at the first noise source 100. Although the second noise source 101 is also located in the air ducts 114, the impeller 115 creates some noise as well. For a better noise-reduction effect, the rigid and firm first noise-reduction component 131 is utilized in the space between the outer side of the impeller 115 and the inner wall of the outer casing 111, while the porous second noise reduction-component 132 is utilized within the hollow impeller fixture 116.

If the second noise-reduction component 132 is used separately, noise reduction can be accomplished only by absorbing sound by the sound-absorbing material. Yet, due to the properties of the second noise-reduction component 132, only part of the noise passing through the second noise-reduction component 132 can be absorbed, and further part thereof still can penetrate through the second noise-reduction component 132. It is to say, in this condition, the noise from the outside can't be effectively isolated. When the second noise-reduction component 132 cooperates with the first noise-reduction component 131, the sound transmission loss caused by the first noise-reduction component 131 is increased. It is to say, at the location of second noise source 101, cooperation between the second noise-reduction component 132 and the first noise-reduction component 131 helps to increase the sound transmission loss caused by the first noise-reduction component 131.

The detailed principle of noise reduction lies particularly as follows: when airflow comes to the first noise source 100 from the base 11, the noise therein can be reduced by the first noise-reduction component 131 which is rigid and compact; when airflow comes to the second noise source 102 from the air inlets 112, the first noise-reduction component 131 cooperates with the second noise-reduction component 132, thereby the noise therein is considerably reduced.

The base 11 is in communication with and is prone to influence from the external environment. During the operation of the fan, it is possible for dust, oil stain and so on in the external environment to come into the fan through the air inlets 112, which also may create some noise. In order to reduce the noise therein and meanwhile to enlarge the airflow into the fan, it is also feasible to set third noise-reduction component 133 in the bottom of the outer casing 111.

The third noise-reduction component 133 is through-holes disposed in the bottom of the outer casing 111.

The third noise-reduction component 133 is effective on both enlarging the airflow into the fan and reducing noise. The diameter of the through-hole is relevant with the wavelength of sound waves which can be calculated according to the frequency and sound speed. The said data can be measured by experiments. The principle of noise reduction of the through-holes is based on the frequency distribution curve of noise. When airflow flows past the through-holes, the frequency distribution curve of noise will move towards the high frequency or the ultrahigh frequency so as to remarkably reduce the audible sound in the frequency distribution curve, thereby abating the interference and damage to human bodies.

Made of a rigid and compact material, the first noise-reduction component 131 is difficult for airflow to pass through, thereby unable to increase the airflow volume into the entire fan through the bottom of the outer casing 111. As the bottom of the outer casing 111 is subjected to dust, oil stain and so on, the second noise-reduction component 132 is easily to block the impeller under the force of strong airflow. In addition, the porous second noise-reduction component 132 is possible to suck the oil, dust and so on in the external environment and become unable to reduce noise. As a result, in the bottom of the outer casing 111, it is appropriate to set a through-hole structure which is effective on reducing noise and enlarging the input of airflow, rather than the first noise-reduction component 131 and the second noise-reduction component 132. This through-hole structure is the third noise-reduction component 133.

Finally, it should be appreciated that the above embodiments are provided only for illustrating, but not for limiting, the technical solutions of the present invention. Although the present invention has been explained in detail in the above embodiments, those skilled in the art should understand that modification to or equivalent replacements of the present invention are allowed without departing from the spirit and scope of the present invention, and the appended claims are intended to cover all these modifications or equivalent replacements which fall within the sprite and scope of the present invention.

Claims

1. A low-noise bladeless fan, comprising a base provided with an impeller fixture and a nozzle located at the top of the base, wherein,

the nozzle comprises an internal passage for receiving airflow through air outlets and an exhaust port, the internal passage is annular and forms a continuous loop or pipe within the nozzle, the exhaust port comprises a conical region tapered to an exit;

being a component which is internally hollow and provided with through-holes in the outer wall thereof, the impeller fixture contiguously or alternately surrounds the impeller, with one of the possible shapes thereof being annular;

within the base, noise-reduction components are set and comprise: a first noise-reduction component, and a second noise-reduction component. Wherein the first noise-reduction component is set on the inner wall of the outer casing, at the interface between the air outlets and the internal passage, and in the space between the outer side of the impeller and the inner wall of the outer casing, for isolating, obstructing and separating noise created inside the outer casing during the operation of the fan;

the second noise-reduction component is disposed within the impeller fixture, with its position and shape matching the position and the shape of the impeller fixture, for absorbing noise created inside the outer casing.

2. The low-noise bladeless fan as claimed in claim 1, wherein,

the nozzle extends substantially orthogonally about the axis to define an opening, the opening having a shape which is circular in an inner track thereof and egg-shaped in an outer track thereof.

3. The low-noise bladeless fan as claimed in claim 1, wherein,

the first noise-reduction component is trapezoidally distributed from the outer casing to the air outlets along the inner wall of the outer casing, with the sectional area in the vicinity of the air outlets smaller than the sectional area in the vicinity of the air inlets, and there is a gap between the first noise-reduction component and the impeller.

4. The low-noise bladeless fan as claimed in claim 3, wherein,

the first noise-reduction component is made of steel plates, lead plates, brick walls or other materials of a greater density.

5. The low-noise bladeless fan as claimed in claim 4, wherein,

the first noise-reduction component is made of one of the materials or any combination of several of them.

6. The low-noise bladeless fan as claimed in claim 2, wherein,

the first noise-reduction component is trapezoidally distributed from the outer casing to the air outlets along the inner wall of the outer casing, with the sectional area in the vicinity of the air outlets smaller than the sectional area in the vicinity of the air inlets, and there is a gap between the first noise-reduction component and the impeller.

7. The low-noise bladeless fan as claimed in claim 6, wherein,

the first noise-reduction component is made of steel plates, lead plates, brick walls or other materials of a greater density.

8. The low-noise bladeless fan as claimed in claim 7, wherein,

the first noise-reduction component is made of one of the materials or any combination of several of them.

9. The low-noise bladeless fan as claimed in claim 1, wherein,

the second noise-reduction component is entirely or partially filled within the impeller fixture.

10. The low-noise bladeless fan as claimed in claim 9, wherein,

the second noise-reduction component is made of slag wool, blankets or other porous sound-absorbing materials.

11. The low-noise bladeless fan as claimed in claim 10, wherein,

the second noise-reduction component is made of one of the materials or any combination of several of them.

12. The low-noise bladeless fan as claimed in claim 2, wherein,

the second noise-reduction component is entirely or partially filled within the impeller fixture.

13. The low-noise bladeless fan as claimed in claim 12, wherein,

the second noise-reduction component is made of slag wool, blankets or other porous sound-absorbing materials.

14. The low-noise bladeless fan as claimed in claim 13, wherein,

the second noise-reduction component is made of one of the materials or any combination of several of them.

15. The low-noise bladeless fan as claimed in claim 1, wherein,

the noise-reduction components further comprise a third noise-reduction component which is through-holes disposed in the bottom of the outer casing.

16. The low-noise bladeless fan as claimed in claim 2, wherein,

the noise-reduction components further comprise a third noise-reduction component which is through-holes disposed in the bottom of the outer casing.