TWI810477B - Centrifugal fan impeller structure - Google Patents

Abstract

A centrifugal fan impeller structure includes a hub and multiple blades extending from an outer circumference of the hub. Each blade has a fixed end, a free end, an upper end face, a lower end face, a front end face and a rear end face. The fixed end and the free end are respectively positioned at two ends of the blade. The fixed end is securely connected with the hub. The upper and lower end faces are respectively positioned on upper and lower sides of the blade. The front and rear end faces are respectively positioned on front and rear sides of the blade. The front and rear end faces define therebetween a thickness. The thickness ranges from 0.05mm to 0.15mm. The blade is tapered from the upper end face to the lower end face, whereby there are two inclinations between the upper and lower end faces. The number of the blades is ≧ 71, whereby the thickness of the blade is minified to increase the number of the blades. By means of the inclinations, the blades are not subject to breakage in the demolding process.

Description

Centrifugal blade structure

The present invention relates to a fan blade structure, in particular to a centrifugal fan blade structure.

The conventional centrifugal fan blade structure is usually made of metal or plastic fan blades. Although the metal fan blade can be made very thin, the weight of the metal fan blade is heavy, which will affect the fan speed, the output air volume and the power used. In addition, the material cost of the metal fan blade and the metal fan blade need to be manufactured separately from the hub during the manufacturing process, resulting in high manufacturing costs.

As for the plastic fan blade, its advantage is that it is lighter in weight, and the material cost of the plastic fan blade is lower, and it can be integrally formed with the wheel hub during the manufacturing process, which can make the production cost lower. However, due to the limitation of the process, the plastic fan blade cannot be produced. It is as thin as a metal fan blade, which also affects the output air volume. It is known that although there are literatures pointing out that the thickness of the plastic fan blade can be made below 0.3mm. However, due to the limitations of the process, the thickness of the known plastic fan blades can only be made as thin as 0.3mm, and cannot be less than 0.3mm, and under this thickness condition, the number of fan blades is between 35 and 70. In actual implementation, due to the insufficient structural strength of the material, and the poor accuracy of the mold system through manual polishing in the conventional and current technology, it is difficult to reduce the thickness of the plastic blades or increase the number of blades. In addition, due to the lack of leaf shape design and insufficient strength of the material structure, the known plastic fan blades are not easy to pull out in the mold, and it is easy to cause draft fractures during the demoulding of the blades, resulting in a failure to reduce the manufacturing cost.

Therefore, how to solve the above-mentioned problems and deficiencies is the direction that researchers in this field will strive for.

One purpose of the present invention is to reduce the thickness of the blades and increase the number of blades to increase the air volume, and make the blades less likely to break during the drafting process.

In order to achieve the above object, the present invention provides a centrifugal fan blade structure, which includes: a plurality of blades extending around the outer edge of the hub, and the blades respectively have a fixed end, a free end, an upper end surface, a lower end surface, a front end surface and A rear end surface, the fixed end and the free end are respectively arranged on opposite ends of the blades, the fixed end is fixedly connected to the hub, the upper and lower end surfaces are respectively arranged on the upper and lower sides of the blades, the front and rear end surfaces are arranged on the front and rear sides of the blades, and define a thickness between the front and rear end faces, the thickness is between 0.05mm and 0.15mm, and the blades are tapered from the upper end face to the lower end face, There are two inclination angles between the upper and lower end faces, and the number of the blades is ≧71.

With the design of the present invention, the thickness of the blades can be reduced, the number of blades can be increased to increase the air volume, and the blades are not easily broken during the drafting process.

10:Centrifugal blade structure

11: hub

111: Outer edge peripheral side

12: blade

121: fixed end

122: free end

123: Upper end face

124: lower end surface

125: front face

126: Rear end face

127: front section

128: middle section

129: Posterior section

13: Fixed ring

t: thickness

t1: Thickness of the upper end face

t2: the thickness of the lower end surface

s: tilt angle

h: height

OD: outer diameter

Figure 1 is a three-dimensional schematic view of the centrifugal fan blade structure of the present invention; Figure 2 is a schematic top view of the centrifugal fan blade structure of the present invention; Figure 3 is an enlarged view of the blade of the centrifugal fan blade structure of the present invention; Figure 4 is It is a schematic cross-sectional view of the blade of the centrifugal fan blade structure of the present invention; the 5th figure is a straight plate-shaped schematic diagram of the blade cross section of the centrifugal fan blade structure of the present invention; the 6th figure is a curved fan of the blade cross section of the centrifugal fan blade structure of the present invention Leaf schematic diagram; the 7th figure is the gradually thickening schematic diagram of the blade of the centrifugal fan blade structure of the present invention; the 8th figure is the gradually thinning schematic diagram of the blade of the centrifugal fan blade structure of the present invention; the 9th figure is the centrifugal fan blade structure of the present invention Schematic diagram of the leaves gradually becoming thicker and then thinner; Figure 10 is a schematic diagram of the blades of the centrifugal fan structure of the present invention gradually becoming thinner and then thicker; Figure 11 is a schematic diagram of the blade fixing ring of the centrifugal fan structure of the present invention.

The above-mentioned purpose of the present invention and its structural and functional characteristics will be described based on the preferred embodiments of the accompanying drawings.

Please refer to Figures 1 and 2, which are perspective views and top views of the first embodiment of the centrifugal fan blade structure of the present invention. As shown in the figure, the centrifugal fan blade structure 10 of the present invention is rotatable and includes a hub 11 and a plurality of blades 12. The hub 11 can be a metal hub or a plastic hub or a combination of the two. In the embodiment of the present invention, the blades are selected as plastic blades.

The hub 11 has an outer peripheral side 111, the outer peripheral side 111 extends the blades 12, and the blades 12 respectively have a fixed end 121, a free end 122, an upper end surface 123, a lower end surface 124, a front end surface 125 and a rear end surface 126, the fixed end 121 and the free end 122 are respectively arranged at the two ends of the blades 12, the fixed end 121 is connected and fixed to the outer edge peripheral side 111 of the hub 11, the upper and lower end surfaces 123 and 124 are respectively arranged on the upper and lower sides of the blades 12, and the front and rear end surfaces 125 and 126 are respectively arranged on the front and rear sides of the blades 12. The face 125 is indicated as the right side of the blade 12 and the rear face 126 is indicated as the left side of the blade 12 .

And define a thickness t between the front and rear end faces 125,126, the thickness t is between 0.05mm and 0.15mm, and the thickness t of the blades 12 is gradually from the upper end face 123 to the lower end face 124 shrink, so the thickness t1 of the upper end surface 123 is greater than the thickness t2 of the lower end surface 124, so that there are two inclination angles between the upper and lower end surfaces 123, 124, and the inclination angles s are between 0.4 degrees and 0.6 degrees. The inclination angle s is the same angle in this embodiment, and may also be a different angle in other embodiments.

A height h is also defined between the upper and lower end surfaces 123, 124, and the height h of the blades 12≦4mm. And the number of the blades 12 is ≧71, wherein the number of the blades 12 is a prime number and is between 71 and 113, and the blades 12 are arranged around the outer peripheral side 111 of the hub 11 to form an outer diameter OD , the outer diameter OD≦52mm of the blades 12 .

In the present embodiment, the thickness t of the blades 12 is 0.1mm, the thickness of the upper end surface 123 of the blades 12 is 0.1mm, and the thickness of the lower end surface 124 of the blades 12 is 0.08mm, and the inclination angles s is 0.5 degrees, the number of these blades 12 is 83 pieces, the height h of these blades 12 is 4mm, and the outer diameter OD of these blades 12 is 52mm, but it is not limited to this. The above parameters need to be changed.

And in the present embodiment, the cross section of these blades 12 is represented as S-shaped blade, but is not limited to this, in actual implementation, the cross section of these blades 12 also can be selected as straight plate shape (as the 5th As shown in the figure) and curved fan blades (as shown in the 6th figure) any one of them or the cross-section of these blades 12 are arranged in any combination of S-shaped blades, straight plate-shaped and curved fan blades.

And these blades 12 have a front section 127, a middle section 128 and a rear section 129, the rear section 129 is adjacent to the fixed end 121, the front section 127 is adjacent to the free end 122, and the middle section 128 connects the front and rear sections 127,129. Between, the thickness t of the front, middle and rear sections 127, 128, 129 is the same in this embodiment, and the thickness t of the front, middle and rear sections 127, 128, 129 is different in other embodiments.

For example, the thickness t of these blades 12 can also be selected to gradually become thicker from the fixed end 121 to the free end 122, that is, the thickness of the front section 127 is greater than that of the middle section 128 and greater than that of the rear section 129 (as shown in Figure 7) and gradually Thinning means that the thickness of the front section 127 is smaller than that of the middle section 128 and that of the rear section 129 (as shown in FIG. 8 ). In addition, the blades 12 can also be arranged in any combination of gradually thicker and gradually thinner blades.

And these blades 12 can also be selected to gradually become thicker and then thinner with a linear change from the fixed end 121 to the free end 122, that is, the thickness of the front and rear sections 127, 129 is smaller than the middle section 128 (as shown in Figure 9) And gradually become thinner and then thicker, that is, the thickness of the front and rear sections 127, 129 is greater than any one of the middle section 128 (as shown in Figure 10). In addition, the blades 12 can also be arranged in any combination of gradually thicker and then thinner blades and gradually thinner and thicker blades.

In an alternative embodiment, the free ends 122 of the blades 12 are connected to form a fixing ring 13 (as shown in FIG. 11 ), so as to enhance the structural strength and stability of the blades 12 during rotation.

In addition, the fan blades 12 and/or the fixing ring 13 are configured by liquid crystal polymer (Liquid Crystal Polymer, LCP) material injection molding, and the liquid crystal polymer material can be mixed with carbon fiber material to increase The structural strength of the fan blades 12 . Due to the good fluidity of the liquid crystal polymer material and the fluid polishing on the surface of the mold, the surface precision of the mold is high, so that the thickness t of the blades 12 can reach 0.05 mm to 0.15 mm, and the thickness t of the blades 12 can be further reduced Finally, the number of blades ≧71 can be set on the outer peripheral side of the hub 11, so that the centrifugal fan blades can increase the air output. In addition, the inclination angles s of the blades 12 are a draft angle, and through the inclination angles s, the blades 12 are not easily broken during the drafting process in the mold.

The liquid crystal polymer (LCP) material is a general term for thermoplastic aromatic polyesters that exhibit liquid crystallinity when in a molten state. Liquid crystal polymers have a rigid molecular structure that is not easy to bend. Its outstanding feature is that the unique molecules of general polymer substances are entangled on it very lightly. Unlike general polymers, there are very few entanglements between molecular chains. Since a small shear force can cause its molecular orientation, the flow resistance during injection molding is very small, and it has excellent molding fluidity. And because the molecules maintain the same molecular configuration as in the molten state during solidification, the volume change of molecular rearrangement is very large. Small, high dimensional accuracy can be obtained. Based on the above characteristics, the liquid crystal polymer (LCP) material is quite suitable for making a thin centrifugal fan blade structure.

The fluid polishing technology can be used for detailed grinding treatment according to various technical requirements, and can also achieve mirror polishing according to different material characteristics and pre-production treatments, or solve the problem of surface treatment and adhesion difficulties. The principle is to add abrasive particles to the soft resin and high fluidity liquid glue according to the needs of grinding or polishing. It is made of a special soft flowing abrasive, which has the characteristics of fluidity and high content of abrasive powder, and passes through the surface of the workpiece in an up and down motion. And the use of super diamond particles and special polishing powder can polish the surface of the mold and achieve the mirror effect. For tungsten steel workpieces, the polishing removal amount is 25~40um, and the surface brightness can reach Ra0.08um. Precision molds require high-precision workpieces. Surface treatment and polishing can reach a surface roughness of Ra0.04um, and the removal amount is about 10um.

Compared with metal fan blades, the plastic centrifugal fan blade structure of the present invention has the advantages of lighter weight, and lower material and production costs. Due to the improvement of technology, the thickness of the plastic centrifugal fan blade structure is already equivalent to that of metal fan blades. Therefore, the plastic centrifugal fan blade structure of the present invention can be used to replace the conventional metal fan blades, thereby achieving the effect of reducing the manufacturing cost.

The present invention has been described in detail above, but what is described above is only a preferred embodiment of the present invention, and should not limit the scope of the present invention. That is, all equivalent changes and modifications made according to the application scope of the present invention shall still fall within the scope of the patent of the present invention.

10:Centrifugal blade structure

11: hub

111: Outer edge peripheral side

12: blade

125: front face

126: Rear end face

Claims (13)

A centrifugal fan blade structure, comprising: a plurality of blades extending around the outer edge of a hub, the blades respectively have a fixed end, a free end, an upper end surface, a lower end surface, a front end surface and a rear end surface, the fixed end and the free ends are respectively arranged at both ends of the blades, the fixed end is fixedly connected to the hub, the upper and lower end surfaces are respectively arranged on the upper and lower sides of the blades, and the front and rear end surfaces are respectively arranged at the front and rear of the blades two sides, and define a thickness between the front and rear end surfaces, the thickness is between 0.05mm and 0.15mm, so that the thickness of the blades is tapered from the upper end surface to the lower end surface, so that the upper and lower end surfaces There are two inclination angles between them, and the number of these blades is ≧71 pieces, and the blades have a front section, a middle section and a rear section, the rear section is adjacent to the fixed end, the front section is adjacent to the free end, and the middle section is connected to the front section. Between the rear segments, the thicknesses of the front, middle and rear segments are selected to be different. The centrifugal blade structure described in item 1 of the scope of the patent application, wherein the thickness of each blade is chosen to be equal, gradually thicker and gradually thinner from the fixed end to the free end, or any combination thereof. The centrifugal fan blade structure as described in item 1 of the scope of the patent application, wherein the thickness of each blade is selected to be either one or any combination of them. The centrifugal fan blade structure described in claim 1 of the patent application, wherein the inclination angle between the upper and lower end surfaces of the blades is between 0.4 degrees and 0.6 degrees. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the angles of the inclination angles are the same or different. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the number of the blades is a prime number ranging from 71 to 113. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the thickness of the upper end surface of the blades is 0.1mm, and the thickness of the lower end surface of the blades is 0.08mm. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the height of the blades≦4mm. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the outer diameter of the blades is ≦52mm. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the fan blades are configured by injection molding of liquid crystal polymer materials. The centrifugal fan blade structure described in item 10 of the scope of the patent application, wherein the liquid crystal polymer materials are mixed with carbon fiber materials. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the cross section of the blades is selected as any one of straight, S-shaped and arc-shaped fan blades or any combination thereof. The centrifugal fan blade structure described in item 1 of the scope of the patent application, wherein the free ends of the blades are connected to form a fixed ring.