1339246 九、發明說明 【發明所屬之技術領域】 本發明是有關可適用於應用在各種用途的馬達、電子 機器和電源設備等之冷卻的風扇馬達之作爲軸承的軸承組 件。 【先前技術】 風扇馬達係爲載置在中央演算元件等的1C封裝上， 且設置在個人電腦和電源設備等的本體框等，藉由旋轉翼 的旋轉導入外氣，或是排出框內的空氣來冷卻電子機器等 。此種風扇馬達係在框形之機殻的中央部固定著馬達，具 有在該旋轉軸安裝風扇的構造。第5圖係槪略表示風扇馬 達之一實施例的縱剖面圖。轉子（回轉翼）係由藉鎖固在回 轉軸3的輪轂4、和形成在輪轂4的風扇5、和固定在輪 轂4之內周側的多極著磁的磁鐵7所構成。機殼係由形成 有空氣孔61的外盒6、和在被固定於外盒6內的軸承殼體 2，從開口部側固定著軸承1之構造的軸承組件、和具備 線圈8的定子9所構成。轉子的旋轉軸3係藉由機殼的軸 承1旋轉自如的支承，驅動轉子的馬達，係藉由轉子的磁 鐵7、機殻的線圈8以及定子9所構成。在此種風扇馬達 中，藉由通電至線圈8，並因線圈8與定子9所產生的旋 轉磁場和具有多極著磁之磁鐵7的磁場的作用，讓轉子被 旋轉驅動，利用形成在轉子的風扇5’產生既定方向的氣 流，從空氣孔6 1進行空氣的吸入或排出。 [S] -4- 1339246 在如上述構造的風扇馬達的軸承·，是採用燒結含油軸 承（例如專利文獻π ’燒結含油軸承是採用在青銅或鐵、 青銅系的多孔質燒結合金的氣孔內，浸漬碳化氫系的合成 油或在碳化氫系合金混合金屬皂作爲增稠劑的合成潤滑油 等的軸承。 〔專利文獻1〕日本特開平10-164794號公報 【發明內容】 〔發明欲解決之課題〕 此種風扇馬達其使用量乃隨著近年個人電腦和遊戲機 等之因高機能化的散熱量增加而增加。其中一方面，希望 風扇馬達之長壽命化和省電化，長壽命化和減低摩擦係數 對使用在風扇馬達的軸承更爲重要。因而，本發明係提供 長壽命、摩擦係數低的軸承爲其課題。 〔用以解決課題之手段〕 爲達成上述之長壽命化和低摩擦化，本發明之軸承組 件’係爲具有：一端形成開口，並且另一端被閉塞的圓筒 狀殻體：和由圓筒狀的燒結體與浸漬在前述燒結體之氣孔 中的潤滑油所形成，外周被固定在前述殼體的內周面’用 以將旋轉軸旋轉自如的支承在內周的圓筒狀燒結軸承的軸 承組件’其特徵爲：在前述燒結軸承的內周面，形成三~ 九條螺旋形的內周溝槽，前述內周溝槽，係在前述內周面 之展開圖中，對軸向呈5〜15。傾斜，並且一端連接至前述 [S3 -5- 1339246 燒結軸承的一端面’另一端自前述燒結軸承的另一端面隔 絕，將前述燒結軸承的一端面配置在前述機殼被閉塞的另 一端側。 〔發明效果〕 藉由本發明的軸承組件，由於能防止潤滑油漏洩’並 能良好的維持滑動面的潤滑狀態，因此使用作爲風扇用軸 承，藉此能延長軸承部分的壽命並減低摩擦係數’有助於 風扇馬達的超壽命化和省電化。 【實施方式】 〔用以實施發明的最佳形態〕 以下，參照圖面說明本發明之軸承組件的一實施形態 。第1圖是構成本發明之軸承組件的燒結含油軸承之一實 施形態，第1圖（a)是軸承I 〇之開放端側的端面圖，第1 圖（b)是軸承10之軸向剖面圖，第1圖（c)是軸承1之閉塞 端側的端面圖。第2圖是使用第1圖之軸承10的軸承組 件之軸向剖面圖，第3圖是第1圖之軸承10的內周面之 展開圖。 構成本發明之軸承組件的軸承1 〇係由燒結合金所製 成的燒結軸承，在其氣孔中浸漬著碳化氫系的合成油，或 在碳化氫系合成油中混合金屬皂作爲增稠劑之合成潤滑油 等的潤滑油。 一般風扇馬達用軸承係採用內徑爲1 .5〜3.5 mm左右， i S] -6- 1339246 軸向之長度爲5~15mm左右的軸承，·本發明之軸承10也 形成同樣的尺寸，藉此例如可適用‘作爲支承第5圖所示之 風扇馬達的回轉軸3的軸承1。於以下，雖是記載有關將 本發明的軸承組件共用於第5圖之風扇馬達的形態，但本 發明的軸承組件並不限於此。 如第1圖（b)所示，在軸承10的內周面11，形成有對 軸向傾斜的螺旋狀之內周溝槽12，該內周溝槽係連接至軸 承1 〇之一方的端面（圖中下側的閉塞側端面1 3 )，自另一 方的端面（圖中上側的開口側端面1 4)被隔絕，未連接。軸 承10係如第2圖所示，壓入或接著而固定在一端形成開 口並且另一端被閉塞之殼體20的內周面，藉此構成軸承 組件。此時，在殼體2 0之被閉塞的另一端側，配置連接 著上述軸承1 〇之內周溝槽的端面（圖中下側的閉塞側端面 1 3 )，在殼體2 0的開口側配置未連接上述軸承1 〇之內周 溝槽的端面（圖中上側的開放側端面1 4)。 上述內周溝槽1 2是作爲儲油的功能，具有將潤滑油 供給到內周面1 1 (滑動面）的作用。又，內周溝槽1 2係爲 如第3圖所示，在內周面11的展開圖中，在與回轉軸3 之滑動方向相反的方向，僅傾斜角度0的螺旋狀傾斜溝槽 。因而，旋轉軸3旋轉的話，旋轉軸3的滑動速度及對應 於sin 0所增加的流動壓，會從閉塞側端面1 3向著開放側 端面1 4施加於內周溝槽1 2的潤滑油。在本發明的軸承組 件中，如上述，形成使內周溝槽1 2傾斜並且連接至閉塞 側端面1 3 ’未連接至開放側端面1 4的構造，藉此可得到 1339246 (1)加大儲油之長邊方向的長度1，提高對滑動面之潤滑作 用的作用、（2 )產生潤滑油沿著內_溝槽1 2流至閉塞側端 面1 3的流動壓，提高閉塞側端面1 3附近的油壓，並提高 供給至內周面之油膜的強度之作用、以及（3 )產生潤滑油沿 著內周溝槽1 2流至閉塞側端面1 3的流壓，藉此防止潤滑 油從燒結含油軸承的開放側端面1 4漏洩，抑制因潤滑油 的消耗降低壽命的作用，爲了提高上述（1)〜（3)的效果，內 周溝槽12的寬以0.2〜1.5mm左右爲宜。但，第3圖之內 周溝槽爲了易於理解，故放大寬度而示之。 上述（1)〜（3)的效果，係在對軸承1〇之內周面的展開 圖之軸向的上述內周溝槽12的傾斜角度0爲20。以下之範 圍（〇<0 S20)觀察，實用上在5〜15。的範圍很有效。傾 斜角度0不滿5°的話’就不能充分獲得上述（1 )〜（3)的作用 。另一方面’傾斜角度0超過1 5。的話，雖然儲油之長邊 方向長度1加大’但由於潤滑油的流動壓變大，潤滑油易 從內周溝槽1 2退開到閉塞側端面1 3，因此結果會降低潤 滑油供給至內周面1 1的作用。因此，內周溝槽1 2的傾斜 角度0係對軸向爲5~15°最適合。 如上述設定內周溝槽12的傾斜角度0 ，內周溝槽12 連接至開放側端面1 4的話’藉由因隨著軸之旋轉的發熱 的潤滑油之膨脹’易發生潤滑油從開放側端面1 4漏洩， 降低軸承的壽命。因此’內周溝槽1 2必須爲未連接到開 放側端面1 4的構造。由此觀點，在上述之一般大小的風 扇馬達用軸承中’開放側之內周溝槽端部15與軸承的端 ' 8 - 1339246 面14之距離d設定在〇.5mm以上爲宜。但內周溝槽端部 15與開放側端面14之距離d過夭的話’由於軸承之內周 面11之往上述（1)的滑動面之潤滑作用下降’因此距離d 以不超過2mm的範圍爲宜。 內周溝槽12之條數太少的話，由於缺乏上述之作用 ，因此爲了使該作用普及到軸承之內周面Η的整體’因 此必須形成三條以上。另一方面，內周溝槽丨2之條數太 多的話，因爲滑動面的面積減少，承受滑動面的面壓增加 ，所以上限爲九條。又，垂直於內周溝槽1 2之長軸方向 的斷面形狀並未特別限定，在第2、4圖中，雖然是形成 溝底的寬小於溝槽之開口寬的梯形，但也可爲寬度一定之 斷面爲長方形的溝槽，或斷面爲三角形、半圓形或半橢圓 形等之溝底狹窄的溝槽。 在具有如上述之構造的軸承組件中，提高內周面11( 滑動面）之素材密度的話，由內周溝槽1 2所供給的潤滑油 變得難以通過燒結含油軸承的氣孔而漏出，潤滑油的壓力 昇高，潤滑油的油膜變堅固。其另一方面，內周溝槽1 2 之溝壁面的素材密度也提高的話，原本具有燒結含油軸承 的潤滑油之循環作用會減損。由該些觀點來看，內周面1 1 的氣孔率形成在5〜28%，內周溝槽12的溝壁面的氣孔率 形成在30〜45%爲宜。爲了形成此種氣孔率的構造，準備 具備氣孔率形成在30〜45%之內周溝溝的燒結含油軸承用 的燒結體素材，在進行分級（sizing )等的再壓縮之際， 使用圓筒狀的核心柱（core rod )，使內周面塑性變形， ί S3 -9- 1339246 消除氣孔，將開口在內周面的氣孔率調整至5〜28%，藉此 得到所要的軸承。 ‘ 在本發明的軸承組件中，如第4圖所示，更在內周溝 槽12連通的側端面13，向著旋轉軸3的旋轉方向，從外 徑側螺旋捲繞至內徑側，形成終端部與前述內周溝槽1 2 連通的端面溝槽1 6爲宜的形態。如上述，在軸承1 0的閉 塞側端面1 3上形成端面溝槽1 6的話，儲存在不隨著旋轉 φ 軸3的旋轉，藉由殻體20與軸承10的閉塞側端面13所 形成的空間的潤滑油，會沿著端面溝槽1 6被引入到旋轉 軸3的方向，將引入的潤滑油供給到內周溝槽1 2，就能提 高對上述（2)之潤滑油的內周面1 1的供給作用。雖然該端 面溝槽16可形成正好與內周溝槽12相同的數量，但也可 少於內周溝槽1 2。以端面溝槽1 6的斷面爲由外徑側向著 內徑側減少的方式形成端面溝槽1 6的話，引入潤滑油的 效率就很優良。 • 如上述，因爲本發明的軸承組件，係藉由具有特定形 態之內徑溝槽的燒結含油軸承與殻體的組合而簡潔的構成 ’所以即可放大軸承的尺又不會讓構造複雜化，能改善潤 滑油的保持性’提高耐久性。因而，例如使用本發明的軸 承組件作爲第5圖之風扇馬達的軸承1及殼體2，藉此提 昇風扇馬達的耐久性，並且可應用於以其他的馬達或各種 旋轉構件爲構成要素的機器裝置的軸承，有助於機器、裝 置的小型化、長壽命化。 [S] -10- 1339246 〔實施例〕 - 將在鐵粉末中添加45質量電解銅粉末、5質量％ 的范狀銅粉末、3質量％的錫粉末的比例所混合的原料粉 末’塡充到模具加以壓縮成型，得到外徑3.5mm、內徑 2.5mm、高度l〇mm之略圓筒形狀的軸承用的成型體（試 料1〜6 )。再者’如表1所示，對每個試料，改變傾斜角 度0，形成六條內周溝槽12。 內周溝槽12’係形成斷面爲寬〇.5mm的長方形，且 連接至一方的端面13 ’未連接至另一方的端面14，內周 溝槽12的端部15與內周溝槽未連接的開放側端面14之 距離爲1mm。又，爲了比較，亦準備內周溝槽12連接到 兩端面13、14的軸承（試料7)。再者，該些之成型體的密 度比係分別將模製壓力調整成7 0 %。將該些成型體在氨分 解氣體環境中以780 °C進行燒結後’再壓縮內周面n，使 內周面11的氣孔率成爲1〇%。再者，內周溝槽12的溝壁 面之氣孔率爲38%。 在已得到的試料’浸漬以具有相當丨s 〇 V G 6 8之粘度 的聚α -燃烴爲主成份的合成潤滑油（商品名FLOIL972P-68，關東化成工業（股）製），製作軸承（試料卜乃。 已得到的軸承（試料1〜7)，係如第2圖所示，以連通 內周溝槽1 2之閉塞側端面1 3與殼體2〇之底部面對面的 方式壓入固定在一端爲開口的不銹鋼製的殼體2〇，製作試 料1 ~ 7的軸承組件。在上述的軸承組件試料，插入由外徑 2.5mm相當】IS S45C材料所製成的旋轉軸3，在環境溫度 -11 - 1339246 80°C，使旋轉軸3以轉數：5000rpm旋轉，測定摩擦係數 ，並且旋轉軸3完成運轉2 0 0小時'後，測定軸承組件試料 的重量’並測定自軸承端面起的潤滑油的耗油率》該些結 果一倂標示於表1。再者，表1的內周溝槽之傾斜角度β ，係爲對內周面〗〗的展開圖的軸向之傾斜角度，6> 的 試料’係形成內周溝槽1 2平行軸向，內周溝槽並未傾斜 之情形的範例。又，試料7，係內周溝槽1 2亦連接在兩端 面1 3、1 4的任—面。 表1 傾斜角度0 (°) 摩擦 係數 耗油率 (% ) 備考 試料 1 0 0.16 17.0 試料 2 2 0.15 15.5 試料 3 5 0.11 8.0 試料 4 10 0.10 6.5 試料 5 15 0.12 8.5 試料 6 20 0.15 16.0 試料 7 10 0.16 27.5 內周溝溝連通至兩端1. Technical Field of the Invention The present invention relates to a bearing assembly as a bearing which can be applied to a fan motor for cooling a motor, an electronic device, and a power source device used in various applications. [Prior Art] The fan motor is placed on a 1C package such as a central calculation element, and is provided in a main body frame such as a personal computer or a power supply device, and is introduced into the outside air by the rotation of the rotary wing or discharged into the frame. Air to cool electronic machines, etc. Such a fan motor has a motor fixed to a central portion of a frame-shaped casing, and has a structure in which a fan is attached to the rotating shaft. Fig. 5 is a longitudinal sectional view showing an embodiment of a fan motor. The rotor (rotary wing) is composed of a hub 4 fixed to the revolving shaft 3 by a lock, a fan 5 formed on the hub 4, and a multi-pole magnet 7 fixed to the inner peripheral side of the hub 4. The casing is composed of an outer casing 6 in which an air hole 61 is formed, a bearing housing 2 fixed in the outer casing 6, a bearing assembly in which the bearing 1 is fixed from the opening side, and a stator 9 having the coil 8. Composition. The rotating shaft 3 of the rotor is rotatably supported by the bearing 1 of the casing, and the motor for driving the rotor is constituted by the magnet 7 of the rotor, the coil 8 of the casing, and the stator 9. In such a fan motor, by energizing the coil 8, and by the action of the rotating magnetic field generated by the coil 8 and the stator 9 and the magnetic field of the magnet 7 having the multipole magnetism, the rotor is rotationally driven and formed in the rotor. The fan 5' generates a flow of air in a predetermined direction, and air is sucked or discharged from the air hole 61. [S] -4- 1339246 The bearing of the fan motor constructed as described above is a sintered oil-impregnated bearing (for example, the patented π 'sintered oil-impregnated bearing is used in the pores of a porous sintered alloy of bronze or iron or bronze type, A synthetic lubricating oil which is impregnated with a hydrocarbon-based synthetic oil or a synthetic lubricating oil in which a hydrocarbon-based alloy is mixed with a metal soap as a thickener. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei 10-164794 (Invention) Problem: The use of such a fan motor has increased with the increase in the amount of heat generated by the high performance of personal computers and game machines in recent years. On the other hand, it is desirable to extend the life and power of the fan motor and to extend the life. The reduction of the friction coefficient is more important for the bearing used in the fan motor. Therefore, the present invention provides a bearing having a long life and a low friction coefficient as a problem. [Means for Solving the Problem] To achieve the above-mentioned long life and low friction The bearing assembly of the present invention has a cylindrical casing having an opening at one end and a closed end at the other end: and a cylindrical burning The body is formed of a lubricating oil immersed in the pores of the sintered body, and the outer circumference is fixed to the inner peripheral surface of the casing 'the bearing assembly of the cylindrical sintered bearing for supporting the inner circumference of the rotating shaft rotatably. It is characterized in that three to nine spiral inner circumferential grooves are formed on the inner circumferential surface of the sintered bearing, and the inner circumferential grooves are in the developed view of the inner circumferential surface, and the axial direction is 5 to 15 Tilting, and one end is connected to the other end of the [S3 -5 - 1339246 sintered bearing one end" and the other end is isolated from the other end surface of the sintered bearing, and one end surface of the sintered bearing is disposed on the other end side of the casing to be blocked [Effect of the Invention] According to the bearing assembly of the present invention, since the lubricating oil can be prevented from leaking and the lubricating state of the sliding surface can be maintained satisfactorily, the bearing for the fan can be used, whereby the life of the bearing portion can be prolonged and the friction coefficient can be reduced. [Embodiment] [Best Mode for Carrying Out the Invention] Hereinafter, a bearing assembly of the present invention will be described with reference to the drawings. Embodiment Fig. 1 is an embodiment of a sintered oil-impregnated bearing constituting a bearing assembly of the present invention, wherein Fig. 1(a) is an end view of the open end side of the bearing I, and Fig. 1(b) is a bearing 10; In the axial cross-sectional view, Fig. 1(c) is an end view of the bearing end side of the bearing 1. Fig. 2 is an axial sectional view of the bearing assembly using the bearing 10 of Fig. 1, and Fig. 3 is a first figure. Development view of the inner peripheral surface of the bearing 10. The bearing 1 constituting the bearing assembly of the present invention is a sintered bearing made of a sintered alloy, impregnated with a hydrocarbon-based synthetic oil in its pores, or synthesized in a hydrocarbon-based system. A lubricating oil such as a synthetic lubricating oil in which a metal soap is mixed with a metal soap as a thickener. Generally, a bearing for a fan motor has an inner diameter of about 1.5 to 3.5 mm, and an i S] -6 to 1339246 has an axial length of 5 to 5 The bearing 10 of about 15 mm is also formed in the same size as the bearing 10 of the present invention. For example, the bearing 1 as the rotary shaft 3 for supporting the fan motor shown in Fig. 5 can be applied. In the following, the bearing assembly of the present invention is collectively used in the fan motor of Fig. 5, but the bearing assembly of the present invention is not limited thereto. As shown in Fig. 1(b), a spiral inner circumferential groove 12 which is inclined to the axial direction is formed on the inner circumferential surface 11 of the bearing 10, and the inner circumferential groove is connected to one end face of the bearing 1 (The lower end side end surface 1 3 in the figure) is isolated from the other end surface (the upper side opening side end surface 14 in the drawing), and is not connected. As shown in Fig. 2, the bearing 10 is press-fitted or attached to the inner peripheral surface of the casing 20 which is formed at one end and which is closed at the other end, thereby constituting a bearing assembly. At this time, on the other end side of the casing 20 that is closed, an end surface (the lower closing side end surface 1 3 in the figure) to which the inner circumferential groove of the bearing 1 is connected is disposed, and the opening of the casing 20 is opened. The side surface is not connected to the end surface of the inner circumferential groove of the above bearing 1 (the upper open side end surface 14 in the figure). The inner circumferential groove 12 functions as an oil reservoir and has a function of supplying lubricating oil to the inner circumferential surface 1 1 (sliding surface). Further, as shown in Fig. 3, the inner circumferential groove 12 is a spiral inclined groove which is inclined at an angle of 0 in a direction opposite to the sliding direction of the rotary shaft 3 in the developed view of the inner circumferential surface 11. Therefore, when the rotary shaft 3 rotates, the sliding speed of the rotary shaft 3 and the flow pressure corresponding to the increase of sin 0 are applied to the lubricating oil of the inner circumferential groove 12 from the closing side end surface 1 3 toward the open side end surface 14 . In the bearing assembly of the present invention, as described above, a configuration is formed in which the inner circumferential groove 12 is inclined and connected to the closing side end surface 1 3 ' not connected to the open side end surface 14 4, whereby 1339246 (1) is enlarged. The length 1 of the longitudinal direction of the oil storage increases the effect of the lubricating action on the sliding surface, and (2) the flow pressure of the lubricating oil flowing along the inner-groove 12 to the end surface 13 of the closing side, and the end surface 1 of the closing side is raised. The oil pressure in the vicinity of 3, and the effect of increasing the strength of the oil film supplied to the inner peripheral surface, and (3) the flow pressure of the lubricating oil flowing along the inner circumferential groove 12 to the end surface 13 of the closing side, thereby preventing lubrication The oil leaks from the open end surface 14 of the sintered oil-impregnated bearing, and the effect of reducing the life due to the consumption of the lubricating oil is suppressed. In order to improve the effects (1) to (3), the width of the inner circumferential groove 12 is about 0.2 to 1.5 mm. It is appropriate. However, the inner groove of Fig. 3 is shown in an enlarged width for easy understanding. The effects of the above (1) to (3) are such that the inclination angle 0 of the inner circumferential groove 12 in the axial direction of the development view of the inner circumferential surface of the bearing 1 is 20 . The following range (〇 <0 S20) is observed, practically 5 to 15. The scope is very effective. If the inclination angle 0 is less than 5°, the effects of the above (1) to (3) cannot be sufficiently obtained. On the other hand, the tilt angle 0 exceeds 15. In this case, although the length 1 of the longitudinal direction of the oil storage is increased, 'the lubricating oil is easily retracted from the inner circumferential groove 12 to the closed side end surface 13 due to the large flow pressure of the lubricating oil, so that the lubricating oil supply is lowered as a result. The role of the inner peripheral surface 1 1 . Therefore, the inclination angle 0 of the inner circumferential groove 12 is most suitable for the axial direction of 5 to 15°. When the inclination angle 0 of the inner circumferential groove 12 is set as described above, and the inner circumferential groove 12 is connected to the open side end surface 14 4, the lubricating oil is easily generated from the open side by the expansion of the lubricating oil due to the heat generated by the rotation of the shaft. The end face 1 4 leaks, reducing the life of the bearing. Therefore, the inner peripheral groove 12 must have a configuration that is not connected to the opening side end face 14 . From this point of view, it is preferable that the distance d between the inner circumferential groove end portion 15 of the open side and the end portion 8 - 1339246 surface 14 of the bearing in the above-described bearing for a fan motor of a general size is set to 〇5 mm or more. However, if the distance d between the inner circumferential groove end portion 15 and the open side end surface 14 is too large, the lubrication effect of the sliding surface of the above (1) is lowered by the inner circumferential surface 11 of the bearing. Therefore, the distance d is not more than 2 mm. It is appropriate. If the number of the inner circumferential grooves 12 is too small, the above-mentioned effects are not obtained. Therefore, in order to spread the effect to the entire inner circumferential surface of the bearing, it is necessary to form three or more. On the other hand, if the number of the inner circumferential grooves 丨2 is too large, since the area of the sliding surface is reduced and the surface pressure of the sliding surface is increased, the upper limit is nine. Further, the cross-sectional shape perpendicular to the long-axis direction of the inner circumferential groove 12 is not particularly limited, and in the second and fourth figures, although the width of the groove bottom is smaller than the width of the opening of the groove, it may be It is a groove having a rectangular shape with a constant width, or a groove having a narrow bottom at the bottom of a triangle, a semicircle or a semi-ellipse. In the bearing assembly having the above-described configuration, when the material density of the inner peripheral surface 11 (sliding surface) is increased, the lubricating oil supplied from the inner circumferential groove 12 becomes difficult to leak by sintering the pores of the oil-impregnated bearing, and is lubricated. The pressure of the oil rises and the oil film of the lubricating oil becomes firm. On the other hand, if the material density of the groove wall surface of the inner circumferential groove 12 is also increased, the circulation action of the lubricating oil originally having the sintered oil-impregnated bearing is degraded. From these viewpoints, the porosity of the inner peripheral surface 11 is 5 to 28%, and the porosity of the groove wall surface of the inner circumferential groove 12 is preferably 30 to 45%. In order to form a structure having such a porosity, a sintered body material for a sintered oil-impregnated bearing having a groove having a porosity of 30 to 45% is prepared, and a cylinder is used for recompression such as sizing. The core rod is plastically deformed, and the inner peripheral surface is plastically deformed. ί S3 -9- 1339246 eliminates the pores and adjusts the porosity of the inner peripheral surface to 5 to 28%, thereby obtaining the desired bearing. In the bearing assembly of the present invention, as shown in Fig. 4, the side end surface 13 that communicates with the inner circumferential groove 12 is spirally wound from the outer diameter side to the inner diameter side in the rotation direction of the rotary shaft 3. The end surface groove 16 in which the end portion communicates with the inner circumferential groove 1 2 is preferably in a form. As described above, when the end surface groove 16 is formed on the closing end surface 13 of the bearing 10, it is stored in the housing 20 and the closing side end surface 13 of the bearing 10 without being rotated by the rotation φ axis 3. The lubricating oil in the space is introduced into the direction of the rotating shaft 3 along the end groove 16, and the introduced lubricating oil is supplied to the inner peripheral groove 12, thereby improving the inner circumference of the lubricating oil of the above (2). The supply of surface 1 1 . Although the end face grooves 16 may be formed in the same number as the inner peripheral grooves 12, they may be smaller than the inner peripheral grooves 12. When the end surface groove 16 is formed such that the cross section of the end surface groove 16 is reduced from the outer diameter side toward the inner diameter side, the efficiency of introducing the lubricating oil is excellent. • As described above, since the bearing assembly of the present invention is simply constructed by a combination of a sintered oil-impregnated bearing having a specific shape of the inner diameter groove and the casing, the scale of the bearing can be enlarged without complicating the structure. , can improve the retention of lubricating oil 'to improve durability. Therefore, for example, the bearing assembly of the present invention is used as the bearing 1 and the casing 2 of the fan motor of Fig. 5, whereby the durability of the fan motor is improved, and it can be applied to a machine having other motors or various rotating members as constituent elements. The bearing of the device contributes to downsizing and long life of the machine and the device. [S] -10- 1339246 [Examples] - A raw material powder in which a ratio of 45 mass of electrolytic copper powder, 5 mass% of normal copper powder, and 3 mass% of tin powder is added to the iron powder is charged The mold was compression-molded to obtain a molded body for a substantially cylindrical bearing having an outer diameter of 3.5 mm, an inner diameter of 2.5 mm, and a height of l〇mm (samples 1 to 6). Further, as shown in Table 1, for each sample, the inclination angle 0 was changed to form six inner circumferential grooves 12. The inner circumferential groove 12' is formed in a rectangular shape having a width of 〇5 mm, and is connected to one end surface 13' not connected to the other end surface 14, and the end portion 15 of the inner circumferential groove 12 and the inner circumferential groove are not The distance between the open side faces 14 of the joints is 1 mm. Further, for comparison, the inner circumferential groove 12 is also connected to the bearings of the both end faces 13, 14 (sample 7). Further, the density ratio of the molded bodies was adjusted to 70% by the molding pressure. These molded bodies were sintered at 780 °C in an ammonia decomposing gas atmosphere, and the inner peripheral surface n was recompressed so that the porosity of the inner peripheral surface 11 became 1%. Further, the groove wall surface of the inner circumferential groove 12 has a porosity of 38%. The obtained sample was impregnated with a synthetic lubricating oil (trade name: FLOIL972P-68, manufactured by Kanto Chemical Industry Co., Ltd.) containing a poly-α-burning hydrocarbon having a viscosity of 丨s 〇 VG 6 8 as a main component, and a bearing was produced ( The obtained bearing (samples 1 to 7) is press-fitted so as to face the bottom surface of the casing 2 连通 with the closing side end face 1 3 of the inner circumferential groove 12 as shown in Fig. 2 . A bearing assembly of Samples 1 to 7 was prepared in a stainless steel case 2 having an opening at one end. In the above-mentioned bearing assembly sample, a rotating shaft 3 made of an outer diameter of 2.5 mm equivalent IS S45C material was inserted in the environment. Temperature -11 - 1339246 80 ° C, the rotating shaft 3 was rotated at a number of revolutions: 5000 rpm, the coefficient of friction was measured, and after the rotating shaft 3 was completed for 200 hours, the weight of the bearing assembly sample was measured and measured from the bearing end face. The fuel consumption rate of the lubricating oil is shown in Table 1. In addition, the inclination angle β of the inner circumferential groove of Table 1 is the axial inclination angle of the developed view of the inner circumferential surface. , 6 > sample 'forms the inner circumferential groove 1 2 parallel axial, inside An example of the case where the circumferential groove is not inclined. Further, the sample 7, the inner circumferential groove 12 is also connected to any one of the end faces 13 and 14. Table 1 Tilt angle 0 (°) Friction coefficient fuel consumption Rate (%) Preparation material 1 0 0.16 17.0 Sample 2 2 0.15 15.5 Sample 3 5 0.11 8.0 Sample 4 10 0.10 6.5 Sample 5 15 0.12 8.5 Sample 6 20 0.15 16.0 Sample 7 10 0.16 27.5 Inner circumference groove connected to both ends
由表1確認，相較於內周溝槽的傾斜角度不滿5。的試 料1及2 '傾斜角度超過15。的試料6，傾斜角度爲5~ 15。 的試料3〜5，係摩擦係數低，且在此範圍呈現良好的滑動 特性。又，試料7與試料3〜5相比，潤滑油的漏出量增多 ’摩擦係數也出現較大的値。由此情形了解到內周溝槽1 2 未連接到殼體20之開口側的端面1 4的構造是很重要的。 ί S1 -12- 1339246 〔產業上的可利用性〕 ' 本發明之軸承組件’最適合應用於風扇馬達等之旋轉 驅動機構，作爲風扇馬達的軸承使用’藉此可提昇馬達的 耐久性，有助於可靠性的提昇。 【圖式簡單說明】 第1圖是有關本發明之風扇馬達用燒結含油軸承之一 實施形態的模式圖’（a)是軸承之開放端側端面的俯視圖’ (b )係軸承之軸向剖面圖，（c)是軸承之閉塞端側端面的仰 視圖。 第2圖是有關本發明之軸承組件之一實施形態的軸向 剖面圖。 第3圖是有關本發明之風扇馬達用軸承之一實施形態 的第圖所示軸承之內周面的展開圖。 第4圖是有關本發明之風扇馬達用軸承之其他實施形 態，在連接內周溝槽之側的端面形成端面溝槽之軸承的俯 視圖。 第5圖是風扇馬達之一例的縱剖面圖。 【主要元件符號說明】 1、1 0 :軸承 1 1 :軸承內周面 1 2 :內周溝槽 1 3 :閉塞側端面 [S] -13- 1339246 1 4 :開放側端面 1 5 :內周溝槽端部 1 6 :端面溝槽 2、20 :軸承殻體 3 :旋轉軸 4 :輪轂（hub) 5 :旋轉翼（風扇） 6 :外盒 6 1 :空氣孔 7 :磁鐵 8 :線圈 9 :定子（stator)It is confirmed from Table 1 that the inclination angle of the inner circumferential groove is less than five. Samples 1 and 2' tilt angles exceed 15. Sample 6, the angle of inclination is 5~15. The samples 3 to 5 had a low coefficient of friction and exhibited good sliding characteristics in this range. Further, in the sample 7, the amount of leakage of the lubricating oil was increased as compared with the samples 3 to 5, and the friction coefficient was also large. From this, it is important to understand that the configuration in which the inner circumferential groove 12 is not connected to the end face 14 of the opening side of the casing 20 is important. ί S1 -12- 1339246 [Industrial Applicability] The bearing assembly of the present invention is most suitable for use in a rotary drive mechanism such as a fan motor, and is used as a bearing of a fan motor to thereby improve the durability of the motor. Helps improve reliability. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an embodiment of a sintered oil-impregnated bearing for a fan motor according to the present invention. (a) is a plan view of an open end side end surface of the bearing. (b) An axial section of the bearing Fig. (c) is a bottom view of the end face of the closed end of the bearing. Fig. 2 is an axial sectional view showing an embodiment of a bearing assembly of the present invention. Fig. 3 is a development view of the inner circumferential surface of the bearing shown in Fig. 1 showing an embodiment of the bearing for a fan motor according to the present invention. Fig. 4 is a plan view showing another embodiment of the bearing for a fan motor according to the present invention, in which a bearing for forming an end face groove is formed on an end face connecting the inner circumferential groove side. Fig. 5 is a longitudinal sectional view showing an example of a fan motor. [Description of main component symbols] 1. 1 0 : Bearing 1 1 : Inner peripheral surface of bearing 1 2 : Inner circumferential groove 1 3 : Closed side end face [S] -13 - 1339246 1 4 : Open side end face 1 5 : Inner circumference Groove end portion 16: end face groove 2, 20: bearing housing 3: rotating shaft 4: hub (hub) 5: rotating wing (fan) 6: outer casing 6 1 : air hole 7: magnet 8: coil 9 :stator