201038826 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種散熱風扇，尤其是一種可降低整 體轴向高度及縮減體積的微型風扇。 【先前技術】 習知散熱風扇’如中國公開第200610072272.8號「 薄型散熱機構」發明專利。請參照第1及2圖所示，該習 知散熱風扇8係包含一框體81，該框體81上方設有一蓋 板82，且該框體81具有一容置空間811 ,該容置空間 811内具有一基座812，該基座812可供設置一電路板83 及一線圈84 ;另外，該基座812設有至少二個以上的定 位元件85，且該基座812中央突設一軸管813，該轴管 813可供一轉子86結合於該框體81之容置空間811，其 中該轉子86内侧具有一磁鐵861，使該線圈84與該磁鐵 861之間可產生磁交鏈作用，以便帶動該轉子86旋轉作 動。藉此，該習知散熱風扇8可裝設於各式電子裝置或電 子儀器’以提供一預定散熱作用。 一般而言，現今電子產品普遍已朝向微型化趨勢等 方向研發設計，然而，由於該習知散熱風扇8之線圈84 係凸出設置於該電路板83之表面，導致該線圈84及該電 路板83兩者仍共同形成一定之軸向高度，造成具有該線 圈84及該電路板83的散熱風扇8難以再進一步縮減整體 軸向高度；因此，亦相對限縮習知散熱風扇8設計成更輕 薄短小化的可行性，而難以安裝於微小型之電子裝置或電 201038826 子儀器。 另一種習知散熱風扇，如中華民國公告第12931〇6號 「薄型風扇」發明專利^請參照第3及4圖所示，該習知 散熱風扇9包含一基座9卜一扇輪92、一片形磁鐵93及 一袖桿94。該基座91設有一轴孔911及一線圈組912 ; 該扇輪92具有數個彎折扇葉921 ;該片形磁鐵93結合於 該扇輪92底部；該轴桿94之一端插設於該基座:軸 〇 孔叫，另一端結合該級92。藉此，該習知散熱風扇$ 同樣可裝設於各式電子裝置或電子儀器，以提供一預定散 熱作用。 然而，上述習知散熱風扇9之基座91及線圈組912 兩者仍共同形成一定之軸向高度，造成該習知散熱風扇9 同樣難以再進一步縮減整體軸向高度，且亦相對限縮可設 。十成更輕薄短小化的可行性，而不適用於微小型之電子裝 置或電子儀器’故仍有加以改善之必要。 〇 【發明内容】 本發明係φξ:供一種微型風扇，用以解決前述各習知 散熱風扇不易朝向微型化方向設計之問題，為主要之發明 目的。 一種微型風扇，包含一框座、一基板及一扇葉。該 框座具有一承載部，該承載部設有一軸座；該基板結合該 框座之承載部，且該基板具有相對之一表層及一底層，該 表層及該底層之間具有一線圈組，該線圈組電性連接一驅 動電路；該扇葉設有一中心轴及一永久磁鐵，該中心轴結 201038826 合該框座之軸座，該永久磁鐵與該線圈組相對。藉此，該 線圈組可形成於該基板之表層及底層之間，使該線圈組^ 被整合於絲板内部，以制減少軸向高度及精簡結構複 雜度等諸多功效。 所述基板由數個電路層相互疊合所構成，該線圈組 包含相互電性連接的數個線圈，各該線圈分別形成於各該 電路層之表面。藉此，即可繞設更多線圈，進而達到提高 轉速及扭矩之功效。 所述基板之其中一電路層的任二相鄰線圈之間形成 一電路舖設區，該驅動電路設置於該電路舖設區。藉此， 以達到降低結構及組裝複雜度之功效。 所述基板之表層及底層可為一絕緣層；另外，該數 個電路層之間亦可各設有一絕緣層。藉此，可提供一絕緣 功效，以確保該微型風扇可正常運作。 +所述基板設有貫穿該表層及該底層之一通孔，該扇 葉之中心軸穿伸該基板之通孔並結合該框座之軸座。藉 此，可達到提升組裝便利性之功效。 一種微型風扇，包含一框座、一基板及一扇葉。該 框座具有-承載部，該承載部設有-軸座；該基板結合該 框座之承載部，且該基板具有一表層，該表層之一側面具 有一線圈組，該線圏組位於該表層與該承載部之間，且該 線圈組電性連接一驅動電路；該扇葉設有一中心軸及一永 久磁鐵，該中心軸結合該框座之軸座，該永久磁鐵與該線 圈組相對。藉此，同樣可達到減少軸向高度之功效，並更 進—步降低整體結構複雜度。 201038826 【實施方式】 為讓本㈣之上収其他目的 '賴域點能更明201038826 VI. Description of the Invention: [Technical Field] The present invention relates to a heat dissipating fan, and more particularly to a micro fan which can reduce the overall axial height and reduce the volume. [Prior Art] A conventional heat-dissipating fan has been invented as disclosed in the Chinese Patent No. 200610072272.8 "Thin-type heat-dissipating mechanism". As shown in the first and second embodiments, the conventional cooling fan 8 includes a frame 81. The cover 81 has a cover 82. The frame 81 has an accommodation space 811. The 811 has a base 812. The base 812 can be provided with a circuit board 83 and a coil 84. In addition, the base 812 is provided with at least two positioning elements 85, and a shaft is protruded from the center of the base 812. a tube 813, the shaft tube 813 is coupled to the accommodating space 811 of the frame 81, wherein the inner side of the rotor 86 has a magnet 861, so that a magnetic interlinkage can be generated between the coil 84 and the magnet 861. In order to drive the rotor 86 to rotate. Thereby, the conventional cooling fan 8 can be mounted on various electronic devices or electronic instruments to provide a predetermined heat dissipation. In general, today's electronic products have generally been developed in the direction of miniaturization, etc. However, since the coil 84 of the conventional cooling fan 8 is convexly disposed on the surface of the circuit board 83, the coil 84 and the circuit board are caused. The two still form a certain axial height together, so that the cooling fan 8 having the coil 84 and the circuit board 83 is difficult to further reduce the overall axial height; therefore, the cooling fan 8 is also designed to be lighter and thinner than the limited reduction. The feasibility of short-term is difficult to install in micro-miniature electronic devices or electric 201038826 sub-instruments. Another conventional cooling fan, such as the Republic of China Announcement No. 12931-6 "Thin Fan" invention patent ^ Please refer to Figures 3 and 4, the conventional cooling fan 9 includes a base 9 a fan wheel 92, A piece of magnet 93 and a sleeve 94. The base 91 is provided with a shaft hole 911 and a coil set 912; the fan wheel 92 has a plurality of bent blades 921; the sheet magnet 93 is coupled to the bottom of the fan wheel 92; one end of the shaft 94 is inserted therein Base: The shaft is called and the other end is combined with the stage 92. Thereby, the conventional cooling fan $ can also be installed in various electronic devices or electronic instruments to provide a predetermined heat dissipation effect. However, the pedestal 91 and the coil assembly 912 of the above-mentioned conventional cooling fan 9 still form a certain axial height together, which makes it difficult for the conventional cooling fan 9 to further reduce the overall axial height, and is also relatively limited. Assume. The feasibility of making it thinner and lighter and shorter, and not suitable for micro-electronic devices or electronic instruments, is still necessary for improvement. SUMMARY OF THE INVENTION The present invention is a micro-fan for solving the above-mentioned problems that the conventional heat-dissipating fan is not easily designed toward the miniaturization direction, and is a main object of the invention. A miniature fan includes a frame base, a substrate and a blade. The frame has a bearing portion, the bearing portion is provided with a shaft seat; the substrate is coupled to the bearing portion of the frame, and the substrate has a surface layer and a bottom layer, and a coil group is disposed between the surface layer and the bottom layer. The coil assembly is electrically connected to a driving circuit; the blade is provided with a central shaft and a permanent magnet, and the central shaft coupling 201038826 is coupled to the shaft seat of the frame, and the permanent magnet is opposite to the coil assembly. Thereby, the coil group can be formed between the surface layer and the bottom layer of the substrate, so that the coil group is integrated into the silk plate to reduce the axial height and the complexity of the structure and the like. The substrate is composed of a plurality of circuit layers stacked on each other, and the coil group includes a plurality of coils electrically connected to each other, and each of the coils is formed on a surface of each of the circuit layers. In this way, more coils can be wound to achieve improved speed and torque. A circuit laying area is formed between any two adjacent coils of one of the circuit layers of the substrate, and the driving circuit is disposed in the circuit laying area. Thereby, the effect of reducing the structure and assembly complexity can be achieved. The surface layer and the bottom layer of the substrate may be an insulating layer; in addition, an insulating layer may be disposed between the plurality of circuit layers. In this way, an insulation effect can be provided to ensure that the micro fan can operate normally. The substrate is provided with a through hole penetrating through the surface layer and the bottom layer, and a central axis of the blade extends through the through hole of the substrate and is coupled to the shaft seat of the frame. As a result, the convenience of assembly can be improved. A miniature fan includes a frame base, a substrate and a blade. The frame has a bearing portion, the bearing portion is provided with a shaft seat, the substrate is coupled to the bearing portion of the frame, and the substrate has a surface layer, and one side of the surface layer has a coil group, and the wire group is located at the frame Between the surface layer and the carrying portion, the coil assembly is electrically connected to a driving circuit; the blade is provided with a central shaft and a permanent magnet, the central shaft is coupled with the shaft seat of the frame, and the permanent magnet is opposite to the coil group . Thereby, the effect of reducing the axial height can also be achieved, and the overall structural complexity can be further reduced. 201038826 [Embodiment] In order to let other purposes above (4), the location of the Lai domain can be more clear.
發明之較佳實施例，並配合所附圖 請參照第5及6 ®所示，本發财-實施例之微型Preferred Embodiments of the Invention, and with reference to the drawings, please refer to Figures 5 and 6®, the mini of the Fortune-Example
.项瓜4耿凤式風扇之扇框，如 圖所示之實施例’係揭示該框座1〇為一軸流式風扇之扇 框。 該基板20具有-表層21，該表層21可為形成於該 基板20表面的一絕緣層（未標示）；又該基板2〇較佳 另具有-底層22 ’該底層22與該表層21相對，且該底 層22亦可為形成於該基板20表面的一絕緣層（未標示) ，使該基板20具有絕緣功能；而該基板2〇係結合該框座 1〇 ’且該基板2〇之底層22可貼接該承載部12。另外， 該基板20較佳選自一印刷電路板，以便利用佈線方式（ layout)於該表層21之一側面形成一線圈組23，該線圈 組23包含有相互電性連接的數個線圈231，並使該線圈 組23可位於該表層21與該承載部12之間；或者，當該 基板20具有一底層22時，該線圈組23較佳位於該基板 20的表層21及底層22之間。 201038826 又，該線圈組23另電性連接一驅動電路（未繪示） ’該驅動電路可直接設置於該基板2G上；或者，該驅動 電路亦可設置於該框座10之容置空間u外，再利用外接 方式電性連接至該線圈組23。另外，該基板2〇設有一通 孔24 ’該通孔24可經由該表層21軸向貫穿至該底層u ’而該線圈組23之各線圈23i較佳環繞於該通孔24周邊 ;藉此，當該基板20結合於該框座1〇之承载部12時， 該框座10之軸座13可穿伸該通孔24。 該扇葉3G包含-葉輪31及-永久磁鐵32。該葉輪 31設有-中心軸州’該中心轴阳穿伸該基板π之通 孔24後，可與該框座1〇之軸座13結合以便該 可於該框座10之容置空間u内旋轉作動;該永久磁鐵 32結合該葉輪31 ’且該永久磁鐵32與該線圈組幻相對 〇 本發明微型風扇於實際使用時，可藉由該驅動電路 致動該線圈組23，使該線圈組23與該永久磁鐵32之間 產生磁交鏈作用，進而帶動該扇葉3G旋轉作動；藉此， ^發明微型風扇可自該進風口 14引入氣流，並利用該扇 :、30之葉輪31進—步驅動該氣流經由該框座⑴之出風 15排散餅界㈣，以便該㈣風扇裝設於 裝置或電t儀器時，可達到一預定散熱作用。 藉由前揭之結構特徵，本發賴型風扇的主要特點 主要包含有：利用該線圈組23形成於該基板20之表層 21之則面（較佳係位於該表層及該底層u之間） 的結構5又5十’使該線圈組23可被整合於該基板内部， 201038826 進而確保該線圈組23不至於凸出該基板2〇的表層21 ; 更重要的是，藉此可使該扇葉30與該基板20的表層21 之間無任何線圈結構設計，且在該線圈組23以佈線方式 而被整合於該基板20内部的條件下，仍不至於過度增加 該基板20的軸向尚度，亦即相對可減少本發明微型風扇 之整體軸向高度，並兼具有精簡結構複雜度之優點；因此 ，當該基板20配合該框座1〇及該扇葉3〇構成本發明微 0 型風扇時，更可相對縮減本發明微型風扇之整體軸向高度 ’以便本發明微型風扇可朝向更輕薄短小化的方向研發設 計。 請參照第7圖所示，本發明第二實施例之微型風扇 同樣包含一框座1〇、一基板40及一扇葉30，其中該框座 1〇及該扇葉30之整體結構與前述第一實施例相同不再贅 述。 請參照第7及8圖所示，本發明第二實施例之基板 〇 40主要係由數個電路層相互疊合所構成；如圖所示之實 施例中，係揭示該基板40由一第一電路層40a、一第二 電路層40b、一第三電路層4〇c及一第四電路層40d所構 成°該數個電路層40a、40b、40c、40d所構成之基板40 同樣具有相對之一表層41及一底層42，該表層41及該 底層42較佳為形成於該基板20表面的一絕緣層（未標示 )’且亦可在該數個電路層4〇a、40b、40c、40d之間各設 有一絕緣層（未繪示）。 . 再者’該基板40同樣可利用佈線方式（layout)於 該表層41之一側面形成一線圈組43，該線圈組43包含 201038826 有相互電性連接的數個線圈431。另外，該基板4〇設有 一通孔44，該通孔44經由該表層41軸向貫穿至該底層 42 ,當該基板40結合該框座1〇之承載部12時，該框座 10之軸座13可穿伸該通孔44。 藉由該數個電路層40a、40b、40c、40d構成該基板 40之結構設計，該數個電路層40a、40b、40c、40d之表 面皆可分別利用佈線方式（layout)形成該數個線圈431 ，用以增加各該線圈431之繞線圈數，藉此，在該基板 20之整體軸向高度不至於過度增加，以及該基板4〇之徑 向寬度尺寸不變的條件下，本發明微型風扇即可繞設更多 線圈431 ’進而提高轉速及扭矩，並同樣可朝向更輕薄短 小化的方向研發設計。 又，請參照第8圖所示，該線圈組43亦可將一驅動 電路45直接形成於一個電路層；如圖所示之實施例中， 係於該第一電路層40a表面設置該驅動電路45，該第一 電路層40a可於任二相鄰線圈431之間形成一電路舖設區 (未標示），以便該驅動電路45具有足夠的空間可設置於 該第一電路層40a表面之電路舖設區；藉此，當該驅動電 路45亦整合於該基板10上時，更可達到降低結構及組裝 複雜度之優點。 如上所述’本發明微型風扇確實可藉由該基板2〇、 40之線圈組23、43位於該基板20、40之表層21、41之 —侧面（較佳係位於該表層21、41及該底層22、42之間 )的結構設計，以有效減少本發明微型風扇之軸向高度， 且相對亦可縮減該微型風扇之整體體積，進而達到便於朝 201038826 向微型化方向研發設計的功能β 雖然本發明已利用上述較佳實施例揭示，然其並非 用以限定本發明，任何熟習此技藝者在不脫離本發明之精 神和範圍之内’相對上述實施例進行各種更動與修改仍屬 本發明所保護之技術範轉，因此本發明之保護範圍當視後 ； 附之申請專利範圍所界定者為準。 【圖式簡單說明】 〇 第1圖：習知第一種散熱風扇之立體分解圖。 第2圖··習知第一種散熱風扇之組合剖視圖。 第3圖：習知第二種散熱風扇之立體分解圖。 第4圖：習知第二種散熱風扇之組合剖視圖。 第5圖·本發明第一實施例微型風扇的立體分解圖。 第6圖·本發明第一實施例微型風扇的組合剖視圖。 第7圖：本發明第二實施例微型風扇的立體分解圖。 第8圖：本發明第二實施例微型風扇之基板的立體分 〇 解圖。 【主要元件符號說明】 〔本發明〕 10框座 11容置空間 12承載部 13 轴座 14 進風口 15出風口 20基板 一 11 一 201038826 21表層 22 底層 23 線圈組 231 線圈 24 通孔 30扇葉 31葉輪 311 中心軸 32 永久磁鐵 40 基板 40a、40b、40c、40d 電路層 41 表層 42 底層 43 線圈組 431 線圈 44 通孔 45 驅動電路 〔習知〕 8 散熱風扇 81 框體 811 容置空間 812基座 813 軸管 82 蓋板 83 電路板 84 線圈 85 定位元件 86轉子 861 磁鐵 9 散熱風扇 91 基座 911 轴孔 912線圈組 92 扇輪 921扇葉 93 片形磁鐵 94 軸桿 —12 —The fan frame of the 瓜 耿 耿 fan, as shown in the figure, reveals that the frame 1 is a fan frame of an axial fan. The substrate 20 has a surface layer 21, which may be an insulating layer (not labeled) formed on the surface of the substrate 20; and the substrate 2b preferably has a bottom layer 22' opposite to the surface layer 21, The bottom layer 22 may also be an insulating layer (not labeled) formed on the surface of the substrate 20, so that the substrate 20 has an insulating function; and the substrate 2 is bonded to the frame 1' and the bottom layer of the substrate 2 22 can be attached to the carrying portion 12. In addition, the substrate 20 is preferably selected from a printed circuit board to form a coil group 23 on one side of the surface layer 21 by using a layout. The coil group 23 includes a plurality of coils 231 electrically connected to each other. The coil assembly 23 can be located between the surface layer 21 and the carrier portion 12; or, when the substrate 20 has a bottom layer 22, the coil assembly 23 is preferably located between the surface layer 21 and the bottom layer 22 of the substrate 20. 201038826 In addition, the coil assembly 23 is electrically connected to a driving circuit (not shown). The driving circuit can be directly disposed on the substrate 2G. Alternatively, the driving circuit can be disposed in the receiving space of the frame 10. In addition, the coil assembly 23 is electrically connected by an external connection. In addition, the substrate 2 is provided with a through hole 24 ′ through which the through hole 24 can be axially penetrated to the bottom layer u ′ and the coils 23 i of the coil group 23 preferably surround the periphery of the through hole 24 ; When the base plate 20 is coupled to the bearing portion 12 of the frame 1 , the shaft seat 13 of the frame 10 can extend through the through hole 24 . The blade 3G includes an impeller 31 and a permanent magnet 32. The impeller 31 is provided with a central axis, and the central axis is inserted into the through hole 24 of the substrate π, and can be coupled with the shaft seat 13 of the frame 1 so that the space can be accommodated in the frame 10. The internal rotation is performed; the permanent magnet 32 is coupled to the impeller 31' and the permanent magnet 32 is opposite to the coil assembly. When the microfan of the present invention is actually used, the coil assembly 23 can be actuated by the driving circuit to make the coil The group 23 and the permanent magnet 32 generate a magnetic interlinking action, thereby driving the blade 3G to rotate; thereby, the invention micro fan can introduce airflow from the air inlet 14 and utilize the fan: 30 impeller 31 The airflow drives the airflow through the air outlet 15 of the frame (1) to disperse the cake boundary (4), so that when the (four) fan is installed in the device or the electric instrument, a predetermined heat dissipation effect can be achieved. The main features of the fan of the present invention include: a surface formed on the surface layer 21 of the substrate 20 by the coil assembly 23 (preferably between the surface layer and the bottom layer u). The structure 5 and 50' enables the coil assembly 23 to be integrated inside the substrate, and 201038826 further ensures that the coil assembly 23 does not protrude from the surface layer 21 of the substrate 2; more importantly, the fan can be thereby There is no coil structure design between the blade 30 and the surface layer 21 of the substrate 20, and under the condition that the coil group 23 is integrated into the substrate 20 by wiring, the axial direction of the substrate 20 is not excessively increased. Degree, that is, relatively reducing the overall axial height of the microfan of the present invention, and having the advantage of reducing the complexity of the structure; therefore, when the substrate 20 is mated with the frame 1 and the blade 3, the invention is microscopically In the case of a 0-type fan, the overall axial height of the micro-fan of the present invention can be relatively reduced, so that the micro-fan of the present invention can be developed in a direction that is lighter, thinner and shorter. As shown in FIG. 7 , the micro-fan of the second embodiment of the present invention also includes a frame 1 , a substrate 40 , and a blade 30 . The overall structure of the frame 1 and the blade 30 is as described above. The first embodiment is the same and will not be described again. Referring to Figures 7 and 8, the substrate stack 40 of the second embodiment of the present invention is mainly composed of a plurality of circuit layers superposed on each other; in the embodiment shown in the figure, the substrate 40 is disclosed by a first A circuit layer 40a, a second circuit layer 40b, a third circuit layer 4〇c, and a fourth circuit layer 40d are formed. The substrate 40 formed by the plurality of circuit layers 40a, 40b, 40c, and 40d also has a relative The surface layer 41 and the bottom layer 42 are preferably an insulating layer (not labeled) formed on the surface of the substrate 20 and may also be in the plurality of circuit layers 4a, 40b, 40c. An insulating layer (not shown) is provided between each of 40d. Further, the substrate 40 can also be formed on a side surface of the surface layer 41 by a wiring pattern, and the coil group 43 includes a plurality of coils 431 which are electrically connected to each other in 201038826. In addition, the substrate 4 is provided with a through hole 44, and the through hole 44 extends axially through the surface layer 41 to the bottom layer 42. When the substrate 40 is coupled to the bearing portion 12 of the frame 1 , the axis of the frame 10 The seat 13 can extend through the through hole 44. The structure of the substrate 40 is formed by the plurality of circuit layers 40a, 40b, 40c, and 40d. The surfaces of the plurality of circuit layers 40a, 40b, 40c, and 40d can be respectively formed by using a layout. 431, in order to increase the number of windings of each of the coils 431, thereby, the micro-invention of the present invention under the condition that the overall axial height of the substrate 20 is not excessively increased, and the radial width dimension of the substrate 4 is constant. The fan can be wound around more coils 431' to increase the speed and torque, and can also be designed in a direction that is lighter, thinner and shorter. Moreover, as shown in FIG. 8, the coil assembly 43 can also directly form a driving circuit 45 on a circuit layer. In the embodiment shown in the figure, the driving circuit is disposed on the surface of the first circuit layer 40a. 45. The first circuit layer 40a can form a circuit laying area (not labeled) between any two adjacent coils 431, so that the driving circuit 45 has sufficient space for circuit laying on the surface of the first circuit layer 40a. Therefore, when the driving circuit 45 is also integrated on the substrate 10, the advantages of reduced structure and assembly complexity can be achieved. As described above, the micro-fan of the present invention can be located on the side of the surface layers 21, 41 of the substrates 20, 40 by the coils 23, 43 of the substrate 2, 40 (preferably located on the surface layers 21, 41 and The structural design of the bottom layers 22, 42) is effective to reduce the axial height of the microfan of the present invention, and relatively reduce the overall volume of the microfan, thereby achieving the function of facilitating the development of the design toward the miniaturization direction of 201038826. The present invention has been disclosed by the above-described preferred embodiments, which are not intended to limit the invention, and it is intended that the invention may be modified and modified without departing from the spirit and scope of the invention. The technical scope of the protection is changed, and therefore the scope of protection of the present invention is considered to be the same as defined in the scope of the patent application. [Simple description of the diagram] 〇 Figure 1: An exploded perspective view of the first type of cooling fan. Fig. 2 is a cross-sectional view showing the combination of the first type of heat radiating fan. Figure 3: An exploded perspective view of a second type of cooling fan. Figure 4: A cross-sectional view of a combination of a conventional second type of cooling fan. Fig. 5 is an exploded perspective view showing the micro fan of the first embodiment of the present invention. Fig. 6 is a sectional view showing the combination of the micro fan of the first embodiment of the present invention. Fig. 7 is an exploded perspective view showing the micro fan of the second embodiment of the present invention. Fig. 8 is a perspective view showing the substrate of the microfan of the second embodiment of the present invention. [Main component symbol description] [Invention] 10 frame 11 accommodating space 12 bearing portion 13 Shaft seat 14 air inlet 15 air outlet 20 substrate one 11 one 201038826 21 surface layer 22 bottom layer 23 coil group 231 coil 24 through hole 30 fan blade 31 impeller 311 central shaft 32 permanent magnet 40 substrate 40a, 40b, 40c, 40d circuit layer 41 surface layer 42 bottom layer 43 coil group 431 coil 44 through hole 45 drive circuit [conventional] 8 cooling fan 81 frame 811 housing space 812 base Block 813 Shaft tube 82 Cover plate 83 Circuit board 84 Coil 85 Positioning element 86 Rotor 861 Magnet 9 Cooling fan 91 Base 911 Shaft hole 912 coil set 92 Fan wheel 921 Blade 93 Piece magnet 94 Shaft - 12 —