200936893 九、發明說明： 【發明所屬之技術領域】 之葉輪。 本發明涉及-種散熱風扇，尤指—種散熱風扇 【先前技術】 隨著電腦產業之迅速發展，CPU追求高速户化一力 能化及小型化所衍生之散熱問題越來越嚴重， 二' 3^任筆記型200936893 IX. Description of the invention: The impeller of the technical field to which the invention pertains. The invention relates to a kind of cooling fan, in particular to a kind of cooling fan. [Prior Art] With the rapid development of the computer industry, the problem of heat dissipation derived from the pursuit of high-speed householdization and miniaturization of the CPU is becoming more and more serious. 3^ notebook type
電腦等内部空間狹小之電子裝置巾更為突出。如果無去將 筆記本電腦内之mi等電子元件所產生之熱量及財效地 散發出去，將極大地f彡響電子元件之工倾能，還會縮減 電子元件之使用哥命，故必須對電子元件進行散熱 目前在電腦内，常採用由導熱體、埶營 a , ， *、’、s 散熱片及散 熱風扇組成之散熱模組對電子元件散熱。 〒热體貼設於電 子元件上’導熱體與散⑽藉由熱管連接，散熱風扇產生 之氣流吹拂散熱片並與散熱片發生熱交換以最終將熱量散 發出去。故，散熱風扇在散熱模組中起著極為重要之作1。 散熱風扇之轉速越高、流速越快、風量越大，則與散熱片 交換之熱量也就更多’從而有效地將電子元件之熱量散 發。然這會導致散熱風扇之噪音増加。利用=FD (Computational Fluid Dynamics，計算流體力學）軟體對習知 散熱風扇_不_驗及流場模擬發現，在散熱風扇之相 鄰葉片之間區域内’伴隨有諸多高次諧波之疊加，從而使 得散熱風扇噪音較大。 【發明内容】 200936893 . 鑒於此，有必要提供一種具較小噪音之散熱風扇及其 . 葉輪。 一種葉輪，包括輪轂及呈放射狀分佈於輪轂週圍之複 數個葉片，該葉片具有一迎風面以及一與該迎風面相對之 背風面，該背風面上開設有複數個軸向凹槽，該複數個軸 向凹槽沿徑向間隔排列，相鄰之二軸向凹槽之間形成一凸 起。 0 —種散熱風扇，包括一底板、一蓋板及連接於該蓋板 與底板之間之一側壁，該蓋板、底板與側壁共同形成容置 一葉輪之容置空間，葉輪包括輪轂及呈放射狀分佈於輪轂 週圍之複數個葉片，該葉片具有一迎風面以及一與該迎風 面相對之背風面，該背風面上開設有複數個軸向凹槽，該 複數個轴向凹槽沿徑向間隔排列，相鄰之二軸向凹槽之間 形成一凸起。 與習知技術相比，本發明之葉片之背風面上開設有軸 ❹ 向凹槽，該軸向凹槽使得葉片之背風面凹凸不平，從而減 少了噪音疊加，降低了散熱風扇之噪音。 【實施方式】 下面將結合圖式對本發明實施例作進一步之詳細說 明。 如圖1所示，散熱風扇10包括一扇框11、收容於扇框 11内之定子（圖中未示出）與葉輪16。 該扇框11包括一底板12、一與底板12平行之蓋板14 200936893 及連接於該蓋板14及底板12之間之側壁13。該蓋板i4、 底板12與側壁13共同形成一容置定子及葉輪16之容置空 間。該蓋板14之中央位置’形成第一入風口 141，該: 13之—側形成一出風口 131。 Λ ' 土 如圖2所示，葉輪16包括一輪較162以及呈玫射狀八 佈於輪fc 162週圍之複數個葉片164。本實施例中，= 16沿逆時針方向旋轉。 "茱輪 ^請—併參閱圖2、3、4,葉片164為-後傾式葉片 葉片托4之尾端輕度彎折並沿與旋轉方向相反之方向傾 斜使葉片164之尾端延伸方向與旋轉切線方向之間2夾 角為鈍角，該葉片164包括一迎風面16乜以及一與迎風面 164a相對之背風面164b。沿葉片164之延伸方向，迎風面 164a之末端和背風面164b之末端藉由一圓弧連接，從而在 背風面164b之末端上形成一圓弧狀之分流倒角168。相對 習知散熱風扇而言，本實施例散熱風扇1〇之迎風面Μ如 之掃風面積不變，保持了原有風壓及風量，分流甸角16^ 則降低了背風面164b對氣流之阻撞，使得氣流更順暢地進 入流道。可以理解地，分流倒角168也可為一斜面，即迎 風面164a之末端和背風面164b之末端藉由該斜面連接， 該斜面與葉片164之迎風面16如之間之夾角為銳角。 該葉片164之背風面164b形成為凹凸不平之結構，在 背風面164b上開設有三個形狀相同、沿徑向間隔排列之第 一軸向凹槽171、第二轴向凹槽172及第三軸向凹槽口3， 第一、第二、第三軸向凹槽171、172、173之開槽方向為 8 200936893 軸線方向’第一軸向凹槽171位於背風面164b上臨近輪轂 162 —側，第三轴向凹槽173位於背風面164b上遠離輪轂 162 —側，第二軸向凹槽172位於第一軸向凹槽171和第二 軸向凹槽173之間，且第一軸向凹槽ι71和第二軸向凹槽 172之間隔距離等於第三轴向凹槽173和第二軸向凹槽172 之間隔距離，相鄰之二軸向凹槽之間形成一凸起174。第 一、第二、第三軸向凹槽171、172、173分別為矩形槽， 其尚度與葉片164之高度相等，在軸向上貫通葉片164之 上、下表面，其邊緣處設有圓角。第一、第二、第三轴向 凹槽171、172、173之深度小於葉片之厚度，不貫通背風 面164b和迎風面164a。 散熱風扇10運轉時，在相鄰葉片164之間持續加壓形 成渴>’IL ’並形成货音豐加。由於第一、第二、第三軸向凹 槽171、172、173使得背風面164b凹凸不平，破壞了噪音 疊加，使得噪音降低。另，第一、第二、第三軸向凹槽171θ、 172、173還破壞了氣流邊界層，減少了分離渦流之產生。 本發明不限定於軸向凹槽之數量、形狀、寬度、深度及位 置，也不限定於軸向凹槽之形狀完全相同，只要在背風面 164b上開設有複數個轴向凹槽，即可實現本發明之技術效 果。例如，該軸向凹槽m、172、173也可為梯形槽，即 軸向凹槽之寬度隨著軸向凹槽之深度增加而逐漸變窄；該 軸向凹槽口卜則乃也可為圓弧槽，即軸向凹槽之底 面為—圓狐面。 圖5為本實施例散熱風扇及習知散熱風扇之頻譜對比 9 200936893 圖’比較兩者在相同轉速情況下噪音-頻率關係曲線，其中 第一曲線為本實施例風扇3〇〇〇轉/分鐘（rpm)時之頻譜曲 線’第二曲線為本實施例風扇4〇〇〇轉/分鐘（rpm)時之頻 谱曲線’第二曲線為習知風扇3〇〇〇轉/分鐘（rpm)時之頻 譜曲線，第四曲線為習知散熱風扇4〇〇〇轉/分鐘（rpm)時 之頻譜曲線。從整體上看’在5〇〇hz到10000HZ範圍内’ 第一、二曲線比第三、四曲線相對平滑，且分別低於第三、 四曲線，這表明在相同轉速情況下，本發明散熱風扇之渦 流減少，而且噪音比習知風扇低。 表1為在相同轉速下本發明散熱風扇及習知散熱風扇 之技術參數對比表。從表1中我們可以發現，在相同轉速 下’相對習知風扇而言，本發明風扇之風壓及風量不變， 而噪音下降了 ldB。 轉速 (rpm) XJ& 也 木曰 (dB) 風壓 (毫米水柱） 風量 (cfm) 習知風扇 3000 29. 9 3. 98 4. 83 4000 39. 1 7. 08 6. 44 本發明風扇 3000 28. 9 4 4. 79 4000 38. 2 7. 11 6. 39 表1 圖6示出本發明之又一較佳實施例，與前述實施例不 同之處在於，葉片264為一直葉式葉片，即葉片264延伸 在一條直線上，葉片264之尾端延伸方向與旋轉切線方向 200936893 之夾角為直角。 本領域技術人員還可於本發明精神内做其他變化。例 如，本發明之葉片164還可為一前傾式葉片，即葉片164 之尾端朝旋轉方向前傾，使葉片164之尾端延伸方向與旋 轉切線方向之0為銳角。底板12之中央位置還可以設置 -第二入風口。這些依據本發明精制做之變化，均應包 含在本發明所要求保護之範圍之内。 ❹ ^所述，本發明符合發明專利之要件，妥依法提出 熟Μ本案2以上所述者僅為本發明之較佳實施例 ，舉凡 Ϊ ，在爰依本發明精神所作之等效修飾 次變化’皆應涵蓋_下之中請專利範圍内。Electronic devices such as computers with small internal space are more prominent. If you do not have to dissipate the heat and financial effects generated by the electronic components such as mi in the notebook computer, it will greatly reduce the work energy of the electronic components, and will also reduce the use of electronic components, so it must be electronic The heat dissipation of the components is currently in the computer, and the heat dissipation module composed of the heat conductor, the camping a, , *, ', s heat sink and the cooling fan is often used to dissipate heat from the electronic components. The heat insulator is attached to the electronic component. The heat conductor and the heat sink (10) are connected by a heat pipe, and the airflow generated by the heat radiating fan blows the heat sink and exchanges heat with the heat sink to finally dissipate the heat. Therefore, the cooling fan plays an extremely important role in the heat dissipation module. The higher the speed of the cooling fan, the faster the flow rate, and the larger the air volume, the more heat is exchanged with the heat sink' to effectively dissipate the heat of the electronic components. This will cause the noise of the cooling fan to increase. Using the =FD (Computational Fluid Dynamics) software for the conventional cooling fan _ non-test and flow field simulation, it is found that there is a superposition of many higher harmonics in the region between adjacent blades of the cooling fan. Therefore, the cooling fan is noisy. SUMMARY OF THE INVENTION In view of this, it is necessary to provide a cooling fan with less noise and its impeller. An impeller includes a hub and a plurality of blades radially distributed around the hub, the blade having a windward surface and a leeward surface opposite to the windward surface, the leeward surface being provided with a plurality of axial grooves, the plurality The axial grooves are arranged at intervals in the radial direction, and a protrusion is formed between the adjacent two axial grooves. A heat dissipation fan includes a bottom plate, a cover plate and a side wall connected between the cover plate and the bottom plate. The cover plate, the bottom plate and the side wall together form an accommodation space for accommodating an impeller, and the impeller includes a hub and a plurality of blades radially distributed around the hub, the blade having a windward surface and a leeward surface opposite to the windward surface, the leeward surface being provided with a plurality of axial grooves, the plurality of axial grooves along the diameter Arranged at intervals, a protrusion is formed between the adjacent two axial grooves. Compared with the prior art, the leeward surface of the blade of the present invention is provided with a shaft yoke groove, which makes the leeward surface of the blade uneven, thereby reducing the noise superimposition and reducing the noise of the cooling fan. [Embodiment] Hereinafter, embodiments of the present invention will be further described in detail with reference to the drawings. As shown in FIG. 1, the heat dissipation fan 10 includes a frame 11, a stator (not shown) housed in the frame 11, and an impeller 16. The frame 11 includes a bottom plate 12, a cover plate 14 200936893 parallel to the bottom plate 12, and a side wall 13 connected between the cover plate 14 and the bottom plate 12. The cover plate i4, the bottom plate 12 and the side wall 13 together form a receiving space for accommodating the stator and the impeller 16. The central position ' of the cover plate 14' forms a first air inlet 141, and the side of the 13 defines an air outlet 131. Λ 'Soil As shown in Fig. 2, the impeller 16 includes a plurality of blades 164 and a plurality of blades 164 that are in the shape of a rose eight around the wheel fc 162. In this embodiment, = 16 is rotated in the counterclockwise direction. "茱轮^请— and referring to Figures 2, 3, and 4, the blade 164 is slightly bent at the trailing end of the rear-tilt blade blade holder 4 and is inclined in a direction opposite to the direction of rotation to extend the trailing end of the blade 164 The angle between the direction and the direction of the tangential rotation is an obtuse angle. The blade 164 includes a windward surface 16A and a leeward surface 164b opposite the windward surface 164a. Along the direction in which the vanes 164 extend, the end of the windward side 164a and the end of the leeward side 164b are joined by a circular arc to form an arcuate split chamfer 168 at the end of the leeward side 164b. Compared with the conventional cooling fan, the windward surface of the cooling fan 1 of the present embodiment has the same sweeping area, and maintains the original wind pressure and air volume. The splitting angle 16^ reduces the leeward surface 164b to the airflow. The collision prevents the airflow from entering the flow channel more smoothly. It can be understood that the split chamfer 168 can also be a slope, that is, the end of the windward surface 164a and the end of the leeward surface 164b are connected by the inclined surface, and the angle between the inclined surface and the windward surface 16 of the blade 164 is an acute angle. The leeward surface 164b of the blade 164 is formed into a rugged structure, and three first axial grooves 171, a second axial groove 172, and a third axis are formed on the leeward surface 164b and are arranged in the same radial direction. To the groove opening 3, the groove direction of the first, second, and third axial grooves 171, 172, 173 is 8 200936893. The direction of the first axial groove 171 is located on the leeward side 164b adjacent to the hub 162. The third axial groove 173 is located on the leeward surface 164b away from the hub 162, and the second axial groove 172 is located between the first axial groove 171 and the second axial groove 173, and the first axial direction The distance between the groove ι 71 and the second axial groove 172 is equal to the distance between the third axial groove 173 and the second axial groove 172, and a protrusion 174 is formed between the adjacent two axial grooves. The first, second, and third axial grooves 171, 172, and 173 are respectively rectangular grooves which are equal in height to the height of the vane 164, and penetrate the upper and lower surfaces of the vane 164 in the axial direction, and have rounds at the edges thereof. angle. The depths of the first, second, and third axial grooves 171, 172, and 173 are smaller than the thickness of the blade and do not penetrate the leeward surface 164b and the windward surface 164a. When the heat radiating fan 10 is in operation, the refrigerant is continuously pressed between the adjacent vanes 164 to form a thirst > 'IL ' and a cargo sound is formed. Since the first, second, and third axial grooves 171, 172, and 173 make the leeward surface 164b uneven, the noise superimposition is destroyed, so that the noise is lowered. In addition, the first, second, and third axial grooves 171θ, 172, and 173 also break the boundary layer of the airflow, reducing the generation of the separation vortex. The invention is not limited to the number, shape, width, depth and position of the axial grooves, and is not limited to the shape of the axial grooves being identical. As long as a plurality of axial grooves are formed on the leeward surface 164b, The technical effect of the present invention is achieved. For example, the axial grooves m, 172, 173 may also be trapezoidal grooves, that is, the width of the axial grooves gradually narrows as the depth of the axial grooves increases; the axial groove can also be used. It is a circular arc groove, that is, the bottom surface of the axial groove is a round fox face. FIG. 5 is a comparison of the frequency spectrum of the cooling fan and the conventional cooling fan of the present embodiment. 9 200936893 FIG. 2 compares the noise-frequency relationship curves of the two at the same rotation speed, wherein the first curve is the fan 3 rpm of the embodiment. (Performance curve at (rpm)' The second curve is the spectrum curve of the fan 4 revolutions per minute (rpm) of the embodiment. The second curve is the conventional fan 3 revolutions per minute (rpm). The spectrum curve, the fourth curve is the spectrum curve of the conventional cooling fan 4 rpm. As a whole, 'in the range of 5〇〇hz to 10000HZ', the first and second curves are relatively smoother than the third and fourth curves, and are lower than the third and fourth curves, respectively, which indicates that the heat dissipation of the present invention is the same at the same rotational speed. The eddy current of the fan is reduced and the noise is lower than that of the conventional fan. Table 1 is a comparison table of technical parameters of the cooling fan of the present invention and a conventional cooling fan at the same rotational speed. From Table 1, we can find that at the same speed, the wind pressure and air volume of the fan of the present invention are unchanged with respect to the conventional fan, and the noise is reduced by ldB. Speed (rpm) XJ& also raft (dB) Wind pressure (mm water column) Air volume (cfm) Conventional fan 3000 29. 9 3. 98 4. 83 4000 39. 1 7. 08 6. 44 Fan 3000 28 of the invention 9 4 4. 79 4000 38. 2 7. 11 6. 39 Table 1 Figure 6 shows a further preferred embodiment of the invention, which differs from the previous embodiment in that the blade 264 is a leaf blade, i.e. The vanes 264 extend in a straight line, and the trailing end of the vane 264 extends at a right angle to the angle of the rotational tangential direction 200936893. Other variations may be made by those skilled in the art within the spirit of the invention. For example, the vane 164 of the present invention may also be a forward-inclined vane, i.e., the trailing end of the vane 164 is inclined forwardly in the direction of rotation such that the trailing end of the vane 164 extends at an acute angle to the rotational tangential direction. The central position of the bottom plate 12 can also be provided with a second air inlet. These variations, which are made in accordance with the invention, are intended to be included within the scope of the invention as claimed. As described in the above, the present invention complies with the requirements of the invention patent, and is well-discussed according to the law. The above description is only a preferred embodiment of the present invention, and the equivalent modification of the equivalent modification in the spirit of the present invention. 'All should be covered _ under the scope of the patent.
11 200936893 【圖式簡單說明】 圖1為本發明散熱風扇一 圖。 較佳實施例之立體分解示 意 圖2為圖1中葉輪之立體圖。 圖3為圖1中葉輪之俯視圖。 圖4為圖3中葉輪局部放大圖。11 200936893 [Simple description of the drawings] Fig. 1 is a view of the cooling fan of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 2 is a perspective view of the impeller of Fig. 1. Figure 3 is a plan view of the impeller of Figure 1. Figure 4 is a partial enlarged view of the impeller of Figure 3.
散熱風扇及習知散熱風扇之頻譜對比圖。 圖6為本發明之葉輪之又―較佳實施例之立體圖。 主要元件符號說明】 10 扇框 11 12 侧壁 13 131 蓋板 14 141 葉輪 16 162 葉片 164 、 264 164a 背風面 164b 168 第一凹槽 171 172 174 墙 一 弟二凹槽 173 散熱風扇 底板 出風口 第一入風口 輪穀 迎風面 分流倒角 第二凹槽 凸起 12Spectrum comparison diagram of the cooling fan and the conventional cooling fan. Figure 6 is a perspective view of a preferred embodiment of the impeller of the present invention. Main component symbol description] 10 fan frame 11 12 side wall 13 131 cover plate 14 141 impeller 16 162 blade 164, 264 164a leeward surface 164b 168 first groove 171 172 174 wall one brother two groove 173 cooling fan bottom plate air outlet An air inlet trough windward surface diverting chamfer second groove protrusion 12