Fan and fan impeller thereof

A fan includes a fan impeller. The fan impeller includes an inner frame, an outer frame and a disturbing structure. The inner frame rotates along a rotation axis. The outer frame is disposed around the inner frame. The blades are disposed between the inner frame and the outer frame and arranged radially. The disturbing structure has a plurality of protrusion columns disposed on the outer frame, and the protrusion columns are arranged surrounding the blades. The protrusion columns are provided to generate vortexes in the flow field for disturbing the flow as to reduce noise, and the wind pressure can be increased to obtain better operating characteristics.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally relates to a fan impeller, and more particularly, to a fan impeller with a comb-shaped disturbing structure.

Description of Related Art

Generally, the operating characteristics of a fan can be improved by adjusting the pitch angle of blades in the blade design or adjusting the extension direction of airfoil, the quantity of blades, and surfaces of existing blades. However, the outputted noise becomes louder as these characteristics are enhanced. As the requirements of heat dissipation in various types of devices are increasing day by day, these devices require a lower noise threshold to operate so as to not become a disturbance. Attempting to achieve a better balance under the two contradictory design parameters is a big problem. Therefore, the standard for evaluating performance of current fan designs is to consider its properties of heat dissipation at a constant noise level. Under this premise, the design of fan blades is a key factor for designing a fan with a low noise in a limited flow channel space, while having better properties of heat dissipation at the same flow resistance.

In the design concept of traditional blades, fan blades have rapid changes of speed and pressure fields at the ends of the blades, and as a side effect, the noise it creates gets louder. The existing technology varies only in pitch angles or blade quantity. However, the fan's operating characteristics cannot be effectively improved while keeping to noise requirements, which makes it difficult to achieve the best design balance of fan speed, its' operating characteristics, and the resulting noise level.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a fan and fan impeller thereof with comb-shaped disturbing structure.

In order to achieve the object mentioned above, the present invention provides a fan impeller including an inner frame, an outer annular frame, a plurality of blades and a disturbing structure. The inner frame rotates along a rotation axis. The outer annular frame is disposed around the inner frame. The blades are disposed between the inner frame and the outer annular frame and are arranged radially. The disturbing structure has a plurality of protrusion columns disposed on the outer annular frame, and the protrusion columns are arranged surrounding the blades.

In the fan impeller of the present invention, the protrusion columns are arranged in multiple layers and surround the blades.

In the fan impeller of the present invention, the outer annular frame has an annular plate body, and the protrusion columns are erected on at least one side of the annular plate body. The protrusion columns are erected on two sides of the annular plate body separately. At least a part of the protrusion columns is arranged along a radial outer edge of the annular plate body. One end of each blade is connected to an inner edge of the annular plate body. Each of the blades further extends to a surface of the annular plate body.

In the fan impeller of the present invention, each of the blades is spaced apart from an adjacent blade to form an outlet channel, and the outlet channel is disposed toward at least one of the protrusion columns. A part of the protrusion columns is arranged on an extension line of each blade.

In the fan impeller of the present invention, the blades include a plurality of long blades and a plurality of short blades staggered in order along a circumference of the inner frame. Two ends of each long blade are connected to the inner frame and the outer annular frame separately, and one end of each short blade is connected to the outer annular frame. Each of the long blades encloses an adjacent long blade to form an inlet channel in an axial direction of the inner frame.

In the fan impeller of the present invention, each of the protrusion columns is a cone column. At least a part of the protrusion columns is not equal in length.

In the fan impeller of the present invention, the inner frame and the outer annular frame constitute a blade plate; and the blades and the protrusion columns are arranged on a surface of the blade plate facing an air inlet.

The present invention further provides a fan including a frame body and a fan impeller as described above. The frame body has an air inlet and an air outlet. The fan impeller is accommodated and pivoted in the frame body. At least a part of the blades is exposed to the air inlet, and the disturbing structure is not exposed to the air inlet.

In the fan and fan impeller of the present invention, the outer circumference of the blade is provided with protrusion columns for disturbing the airflow. Thus, vortexes in the flow field can be generated to suppress the turbulence as to reduce noise, and the wind pressure can be increased to obtain better operating characteristics. Therefore, the fan impeller of the present invention can meet the requirements of heat dissipation and noise reduction of system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In cooperation with attached drawings, the technical contents and detailed description of the invention are described thereinafter according to a number of preferable embodiments, not being used to limit its executing scope. Any equivalent variation or modification made according to appended claims is all covered by the claims claimed by the present invention.

Please refer toFIG. 1toFIG. 3. The first embodiment of the present invention provides a fan. The fan includes a frame body10and a fan impeller20accommodated and pivoted in the frame body10, and the frame body10is configured in a shape of flat shoulder. One side of the frame body10is provided with an air inlet11, and an air outlet12is provided at one side edge of the frame body10. The fan impeller20includes an inner frame100, an outer annular frame200, a plurality of blades30and a disturbing structure400.

In the present embodiment, the inner frame100is preferably a torus. A rotor and a rotating shaft can be disposed in the inner frame100and are capable of rotating along a rotation axis A.

The outer annular frame20is disposed around the inner frame100. In the present embodiment, the outer annular frame200has an annular plate body210. The annular plate body210and the inner frame100are preferably arranged concentrically.

With referring toFIG. 3andFIG. 4, the blades300are disposed between the inner frame100and the outer annular frame200and are arranged radially. Preferably, the inner frame100, the outer annular frame200and the blade300are integrally formed as one piece, but the invention is not limited thereto. Specifically, one end of each blade300is connected to an inner edge of the annular plate body210, and one side of each blade300is connected to the annular plate body210. Each of the blades300can optionally extend to a surface of the annular plate body210(for example, the surface facing the air inlet11), but the invention is not limited thereto.

In the present embodiment, the blades300have a plurality of long blades310and a plurality of short blades320staggered in order along a circumference of the inner frame100. Two ends of each long blade310are connected to the inner frame100and the outer annular frame200separately, and one end of each short blade320is connected to the outer annular frame200. In addition to driving the airflow, each long blade310is connected between the inner frame100and the outer annular frame200as fan impeller structures. However, each short blade320is only used to drive the airflow without connecting to the inner frame100. Specifically, each of the long blades310encloses an adjacent long blade310to form an air inlet channel301in an axial direction of the inner frame100; each long blade310and an adjacent short blade320are arranged in staggered to form an outlet channel302. With long blades310and short blades320arranged alternately, the spacing between adjacent long blades310can be increased without reducing the airflow capacity of the blades300(that is, the quantity of blades300is not reduced). Thus, a larger inlet channel301can be formed to increase the air intake, and the resistance of flow field in the inlet channel301can be reduced.

Please refer toFIG. 4andFIG. 5. The disturbing structure400has a plurality of protrusion columns410disposed on the outer annular frame200. In the present embodiment, the protrusion columns410are cylinders with equal-length, which can reduce the resistance of flow field of airflow passing through the protrusion columns410, but the present invention is not limited thereto. The protrusion column410can also be a column of other cross-sectional shapes, such as a column with an elliptical or a drop-shaped cross section. Moreover, each of the protrusion columns410can be a cone column, and the length of the protrusion columns may not be equal. In the present embodiment, the protrusion columns410are erected on one side of the annular plate body210(in the present embodiment, the side facing the air inlet11). The protrusion columns410are arranged surrounding the blades300, and each outlet channel302is disposed toward at least one of the protrusion columns410, so that the airflow leaving the blade300through the outlet channels302can pass through the protrusion columns410. When the airflow passes through the protrusion columns410, the protrusion column410can induce vortexes on leeward sides thereof; thus, achieving the effect of directing airflow to reduce the noise of the flow field. Furthermore, the protrusion columns410can also increase the pressure difference between the upstream and downstream of the flow field to improve the performance of the fan impeller. Preferably, the protrusion columns410are arranged in multiple layers and surround the blades300to increase the density of vortexes. In addition, at least a part of the protrusion columns410are arranged along a radial outer edge of the annular plate body210, and a part of the protrusion columns410are arranged on an extension line of each blade300; thus, the outflow from each outlet channel302can also pass through the protrusion columns410, so that the airflow can induce vortexes by each protrusion column410. Therefore, a better effect of directing airflow will be achieved, and the noise of flow field can be reduced at the same time.

Please refer toFIG. 1. In the present embodiment, blade roots of the long blades310among the blades300of the fan impeller20of the fan are exposed to the air inlet11. The short blades320are covered by the frame body10without exposing to the air inlet11. Moreover, with referring toFIG. 6andFIG. 7, when the fan impeller20rotates, at least a part of the disturbing structure400is exposed to the air outlet12, and the disturbing structure400is shielded by the frame body without being exposed to the air inlet11. Therefore, the disturbing structure400can be ensured to only interfere with the outflow without obstructing the inflow.

The inner frame100and the outer annular frame200of the fan impeller20of the present embodiment are integrated to form a single blade plate, so that each blade300and each protrusion column410of the disturbing structure400are both disposed on the surface of the blade plate facing the air inlet11. The protrusion columns410can also induce vortexes; thereby achieving the effect of directing airflow to reduce the noise of the flow field. Please refer toFIG. 8toFIG. 10. The second embodiment of the present invention provides a fan. The fan includes a frame body10and a fan impeller20aaccommodated and pivoted in the frame body10. The frame body10is configured in a shape of flat shoulder. One side of the frame body10is provided with an air inlet11, and an air outlet12is provided at one side edge of the frame body10. The fan impeller20aincludes an inner frame100, an outer annular frame200, a plurality of blades30and a disturbing structure400.

In the present embodiment, the inner frame100is preferably a cylindrical shell with one end closed. A rotor and a rotating shaft can be disposed in the inner frame100and are capable of rotating along a rotation axis A.

The outer annular frame200is disposed around the inner frame100. In the present embodiment, the outer annular frame200has an annular plate body210. The annular plate body210and the inner frame100are preferably arranged concentrically.

Please refer toFIG. 10toFIG. 12. The blades300are disposed between the inner frame100and the outer annular frame200and are arranged radially. Preferably, the inner frame100, the outer annular frame200and the blade300are integrally formed as one piece, but the invention is not limited thereto. Specifically, a center of one end of each blade300is connected to an inner edge of the annular plate body210; therefore, airflow enter through both sides of the annular plate210. In addition, each of the blades300can optionally extend to a surface of the annular plate body210, but the invention is not limited thereto.

In the present embodiment, the blades300have a plurality of long blades310and a plurality of short blades320staggered in order along a circumference of the inner frame100. Two ends of each long blade310are connected to the inner frame100and the outer annular frame200separately, and one end of each short blade320is connected to the outer annular frame200. In addition to driving the airflow, each long blade310is connected between the inner frame100and the outer annular frame200as fan impeller structures. However, each short blade320is used to drive the airflow without connecting to the inner frame100. Specifically, each long blade310encloses an adjacent long blade310to form an air inlet channel301in an axial direction of the inner frame100. Each blade300is spaced apart from an adjacent blade300to form an outlet channel302a,302bon both sides of the annular plate body210separately. With long blades310and short blades320arranged alternately, the spacing between adjacent long blades310can be increased without reducing the airflow capacity of the blades300(that is, the quantity of blades300is not reduced). Thus, a larger inlet channel301can be formed to increase the air intake, and the resistance of flow field in the inlet channel301can be reduced.

The disturbing structure400is preferably comb-shaped. Specifically, the disturbing structure400has a plurality of protrusion columns410a,410bdisposed on the outer annular frame200. In the present embodiment, the protrusion columns410a,410bare cylinders with equal-length, but the present invention is not limited thereto. The protrusion column410can also be a column of other cross-sectional shapes, such as a column with an elliptical or a drop-shaped cross section which can reduce the resistance of flow field of airflow passing through the protrusion columns410a,410b. Moreover, each of the protrusion columns410a,410bcan be a cone column, and the length of the protrusion columns410amay not be equal. In the present embodiment, the protrusion columns410a,410bare erected on two sides of the annular plate body210. The protrusion columns410a,410bare arranged surrounding the blades300, and each outlet channel302a,302bis disposed toward at least one of the protrusion columns410a,410b, so that the airflow leaving the blade300through the outlet channels302a,302bcan pass through the protrusion columns410a,410b. When the airflow pass through the protrusion columns410a,410b, the protrusion column410a,410bcan induce vortexes on leeward sides thereof; thereby achieving the effect of directing airflow to reduce noise of the flow field. Furthermore, the protrusion columns410a,410bcan also increase the pressure difference between the upstream and downstream of the flow field to improve the performance of the fan impeller. Preferably, the protrusion columns410a,410bare arranged in multiple layers and surround the blades300to increase the density of the vortexes. In addition, at least a part of the protrusion columns410a,410bare arranged along a radial outer edge of the annular plate body210, and a part of the protrusion columns410a,410bare arranged on an extension line of each blade300. Therefore, the outflow from each outlet channel302a,302bcan also pass through the protrusion columns410a,410b.

Please refer toFIG. 8. In the present embodiment, blade roots of the long blades310among blades300of the fan impeller20aof the fan are exposed to the air inlet11. The short blades320are covered by the frame body10without being exposed to the air inlet11. Moreover, with referring toFIG. 13andFIG. 14, when the fan impeller20arotates, at least a part of the disturbing structure400is exposed to the air outlet12, and the disturbing structure400is shielded by the frame body without exposing to the air inlet11. Therefore, the disturbing structure400can be ensured to only interfere with the outflow without obstructing the inflow.

In the present invention, the outer circumference of the blades300of the fan impeller are provided with protrusion columns410,410a,410bfor disturbing the airflow. Thus, vortexes in the flow field can be generated to suppress the turbulence as to reduce noise, and the wind pressure can be increased to obtain better operating characteristics. Therefore, the fan impeller of the present invention can meet the requirements of heat dissipation and noise reduction of the system.

Furthermore, the height of protrusion columns410,410a,410bof the fan impeller of the present invention can be directly adjusted on the molds to balance the fan impeller. The blade300can be produced by plastic injection, die casting, metal stamping or injection molding etc.