200901601 九、發明說明 【發明所屬之技術領域】 本發明是關於當作FA( factory automation)或〇A( office automation)等的產業領域用的驅動電動機、或者 電動汽車用的驅動馬達來使用，並且具備有將迴轉磁場形 成用的複數個空心形狀線圈捲裝在定子鐵心而形成之電樞 繞組、及裝設在轉子軛之永久磁鐵之永磁式無刷電動機， 尤其是關於將迴轉檢測器配置在沒有用托架等來隔間的相 同空間中之附有迴轉檢測器的電動機的耐雜訊構造。 【先前技術】 過去’當作FA或OA等的產業領域用的驅動電動機 、或者近年’當作電動汽車用的驅動馬達來使用，並且具 備有將迴轉磁場形成用的複數個空心形狀線圈捲裝在定子 鐵心而形成之電樞繞組、及裝設在轉子軛之永久磁鐵之永 磁式無刷電動機’提案有例如日本專利文獻1中所述的構 成。這種構成的永磁式電動機，大多是將用來檢測出轉子 的位置之迴轉fe測器’配置在用托架來對於電樞繞組或永 久磁鐵進彳了隔間的另一個空間中的情況。 與上述構成不同’並沒有用托架來對於電樞繞組與永 久磁鐵進行隔間’將迴轉檢測器配置在與電樞繞組或永久 磁鐵相同空間而形成之附有迴轉檢測器的電動機，如同第 5圖的構成。此外，第5圖爲習知的永磁式無刷電動機之 側面剖面圖。第6圖爲表示沿著第5圖中的a — a線之電 -4- 200901601 動機的全體構成之正面剖面圖。此處則是以1 8個極、1 5 個線圈之內部轉子型間隙繞組電動機爲例來進行說明° 圖中，圖號1爲定子鐵心，圖號2爲空心線圈，圖號 3爲定子，圖號4爲框架’圖號5爲轉子軛’圖號6爲從 動軸，圖號7爲永久磁鐵，圖號8爲轉子’圖號9爲迴轉 檢測器，圖號10爲迴轉盤，圖號11爲軸承’圖號12爲 空隙部，圖號1 5爲基體。 永磁式電動機的定子3係由層積矽鋼板所成形之大致 圓筒狀的定子鐵心1、及以等間隔捲裝：隔著用來確保所 要的絕緣耐壓之薄絕緣板所捲裝的複數個空心線圏2而形 成之電樞繞組所構成。該電樞繞組係用樹脂來加以模塑或 浸滲，與定子1 一體緊固在一起。此外，空心線圈2的結 線則是藉由一線到底所繞捲的線圈所成形。 另外’轉子8係由與該定子3隔著磁隙呈同心圓狀配 置之大致杯状的轉子軛5、及裝設在該轉子軛5的鍔部5 a 並且具有交互極性不同的複數個磁極，且被分割成圓弧狀 之稀土類的永久磁鐵7所構成。然後，轉子8透過被嵌合 在從動軸6並且與定子8之間，安裝在從動軸6的內周之 軸承11而迴轉自如地支承著。 另外’迴轉盤10安裝在與轉子8 —體的從動軸6，檢 測出該迴轉盤的位置之迴轉檢測器，設置在位於轉子軛之 鳄部的內側的空間部。 專利文獻1 :日本專利特開2 〇 〇 2 _ 1 〇丨5 9 5號公報（提 案書中第2頁、第1〜2圖） 200901601 【發明內容】 <發明所欲解決之課題> 如同日本專利文獻1，相對於空心線圈2或永久磁鐵 7，迴轉檢測器9則是配置在用托架隔間的另外一個空間 之構成，可以避免受到來自空心線圈2之電磁雜訊的影響 ，但相反，零件件數增多，全長變長，故會有生產性、成 本上均變差的課題。 另外，如同第5圖所示的技術，並沒有用托架來隔間 ，在與定子線圈1或永久磁鐵7相同空間配置迴轉檢測器 9的情況，由於離定子線圈1的距離變近，故會有受到電 磁雜訊的影響或構造零組件造成FG ( frame ground )雜訊 的影響，使檢測脈衝波跳動等影響到可靠度的問題。 本發明係鑒於這問題點而提案，其目的是提供使安裝 在電動機之迴轉檢測器的耐雜訊提升，電動機可小型化， 生產性、可靠度、成本上均優異之永磁式無刷電動機。 <用以解決課題之手段> 爲了要解決上述問題，本發明由以下方式所構成。 本發明的申請專利範圍第1項所述之永磁式無刷直流 電動機，是一種具備有：由大致圓筒狀的定子鐵心及將迴 轉磁場形成用的複數個空心狀線圈，捲裝在該定子鐵心的 內周或外周的任一方而形成之電樞繞組所構成之定子' & 由隔著前述定子和磁隙呈同心圓狀對向配置之大致杯狀的 -6- 200901601 轉子軛、及裝設在該轉子軛的鍔部並且具有交互極性不同 的複數個磁極之永久磁鐵所構成之轉子、及被設置在位於 前述轉子軛之鍔部的內側之空間部，檢測出前述轉子的位 置之迴轉檢測器之永磁式無刷直流電動，其特徵爲：在前 述定子鐵心配置遮蔽板，該遮蔽板是用來將前述空心線圈 的線圏終端部與前述轉子軛所圍成的空隙部中從該空心狀 線圈所產生之電磁雜訊予以遮蔽。 本發明的申請專利範圍第2項所述之永磁式無刷直流 電動機，係如同申請專利範圍第1項所述之永磁式無刷直 流電動機，其中，前述遮蔽板爲以覆蓋前述空心線圈的線 .圏終端的方式，朝向前述永久磁鐵的端部呈大致L形狀彎 折的構成。 本發明的申請專利範圍第3項所述之永磁式無刷直流 電動機，係如同申請專利範圍第1項所述之永磁式無刷直 流電動機，其中，在前述定子鐵心的內周或外周的任一方 ，設置支撐該定子之框架，並且成爲將前述遮蔽板夾在前 述定子鐵心與前述框架之間的構成，使該遮蔽板的FG ( frame ground )連接、定位固定變容易。 本發明的申請專利範圍第4項所述之永磁式無刷直流 電動機，係如同申請專利範圍第1或2或3項所述之永磁 式無刷直流電動機，其中，前述遮蔽板係以可將呈直線狀 延伸的板材成形爲大致呈圓弧狀的方式’具有複數個切槽 〇 本發明的申請專利範圍第5項所述之永磁式無刷直流 -7- 200901601 電動機’係如同申請專利範圍第1項所述之永磁式無刷直 流電動機’其中，前述轉子軛的鍔部係比前述迴轉檢測部 的安裝位置還要更朝向反負荷側，在軸方向上延伸設置。 本發明的申請專利範圍第6項所述之永磁式無刷直流 電動機’係如同申請專利範圍第1或5項所述之永磁式無 刷直流電動機’其中，前述轉子軛的鍔部，形成爲壁厚從 與前述迴轉檢測器的安裝位置相對向的反負荷側的端部， 朝向負荷側的基部變大之推拔形狀。 [發明效果] 依據申請專利範圍第1項所述之永磁式無刷直流電動 機’因設有遮蔽板，可以防止由空心線圈所產生的電磁雜 訊來到迴轉檢測器，所以即使是定子線圈的附近仍能夠配 置迴轉檢測器。 依據申請專利範圍第2和3項所述之永磁式無刷直流 電動機，藉由將遮蔽板的剖面設成L形狀，夾入在定子鐵 心與框架之間，即使不使用螺絲等仍能夠定位，同時還可 以與FG連接。 另外，依據申請專利範圍第4項所述之永磁式無刷直 流電動機，設有可將遮蔽板成形爲圓弧狀的切槽，因而可 以呈直線狀製作遮蔽板，能夠改善作業性及削減成本。 另外，依據申請專利範圍第5項所述之永磁式無刷直 流電動機，由於是比迴轉檢測器的配置位置還要更朝向反 負荷側，延伸設置轉子軛的端面，迴轉檢測器則對於由空 -8- 200901601 心線圈所產生的電磁雜訊變成曲徑構造，故能夠大幅抑制 電磁雜訊，提高可靠度。 【實施方式】 以下，參考圖面來說明本發明的實施形態。 <實施例1 > 第1圖爲表示本發明的第1實施例的永磁式無刷電動 機之側面剖面圖。第2圖爲表示沿著第1圖中的A ~ A線 之電動機的全體構成之正面剖面圖。第3圖爲本發明的永 磁式無刷電動機所適用的遮蔽板之側面圖。第4圖爲將習 知的遮蔽板成形爲圓弧狀經展開之側面圖。 此外，本實施例爲與習知例子相同之1 8個極、1 5個 線圈之內部轉子型間隙繞組電動機的一個例子，本發明的 構成要件中，有關與習知技術相同點，其說明則省略，只 針對不同點進行說明。 本發明與習知技術上的不同點，以下進行說明。 即是不同點爲在定子鐵心1配置遮蔽板1 3，該遮蔽板 則是在由空心線圏2的線圈終端部與轉子軛5所圍成的空 隙部1 2中用來將從該空心線圈2所產生的電磁雜訊予以 遮蔽’該遮蔽版1 3係形成爲以覆蓋空心線圏2的線圈終 端的方式，朝向永久磁鐵7的端部呈大致L形狀彎折的構 成。 另外’在定子鐵心1的內周，設置支撐該定子3之框 -9- 200901601 架4，並且成爲將遮蔽板13夾在定子鐵心1與框架4之間 的構成，使該遮蔽板13的FG( frame ground:框架接地 )連接、定位固定變容易。該遮蔽板係以可將呈直線狀延 伸的板材成形爲大致圓弧狀的方式，具有複數個切槽。 另外，迴轉軛5的鍔部5a係比迴轉檢測器9的安裝 位置還要更朝向反負荷側，在向軸方向上延伸設置，具體 上，最好是以當將鍔部5a的端部與將轉子軛5固定在從 動軸6的基部之間的軸方向長度設爲L 1，將迴轉檢測器9 的安裝位置與轉子軛5的基部之間的軸方向長度設爲L2 時，成爲L1>L2的關係的方式，規定鍔部5a的軸方向長 度。進而，迴轉軛5的鍔部5 a形成爲壁厚從與迴轉檢測 器9的安裝位置相對向的反負荷側之轉子軛5的端部，朝 向負荷側之轉子軛5的基部變大之推拔形狀。 其次，針對動作進行說明。 如同上述手段，在定子心1與框架4之間設置L形狀 的剖面形狀之遮蔽板1 3，再比迴轉檢測器9的安裝位置還 要更朝向反負荷側，延伸設置迴轉軛5的鍔部5 a，則由空 心線圏2所產生的電磁雜訊，藉由由呈L形狀彎折的遮蔽 板1 3、迴轉軛5的鍔部5 a所分別形成之曲徑構造來遮蔽 ’藉由此方式，即使迴轉檢測器9接近空心線圏的附近， 仍不會受到來自空心線圈2之電磁雜訊的影響。 另外，將轉子軛5的軛部5 a的內徑側改良成從反負 荷側的端部朝向負荷側的基部來使厚度變化的推拔狀，則 可以防止由轉子軛5所產生的電力線集中，即使迴轉檢測 -10- 200901601 器9接近轉子軛，仍不會受到來自轉子軛5之磁束的影響 〇 因此，本發明的實施例係因將遮蔽板設置在空心線圈 的線圈終端部與轉子軛所圍成之空隙部，並且將轉子軛的 軛部的端部向反負荷側延伸，分別構成覆蓋迴轉檢測器之 曲徑構造，所以可以利用定子與轉子之間的空隙部來遮蔽 由空心線圏所放出的電磁雜訊，該結果，可以防止電磁雜 訊來到迴轉檢測器9，可靠度提高。另外，將迴轉檢測器 配置在與空心線圈或永久磁鐵相同的空間，故電動機能夠 小型化。 另外，也可以遮蔽板的剖面設成L形狀，藉由夾入在 定子鐵心與框架之間’不使用螺絲等就能夠定位，同時與 F G連接。進而，呈直線狀製造遮蔽板，置入可成形爲圓 弧狀的切槽，能夠改善作業性及削減製造成本。 以上，可以獲得可靠度、作業性、成本上均優異之附 有迴轉檢測器的永磁式電動機。 [產業上的可利用性] 本發明的永磁式無刷電動機係以覆蓋空心線圈的線圈 終端的方式，設置：朝向永久磁鐵的端部呈大致L形狀彎 折的構成之遮蔽板，以防止由空心線圏所產生之電磁雜訊 來到迴轉檢測器’因即使是定子線圈的附近仍能夠配置迴 轉檢測器’所以除了 FA或OA等的產業領域的驅動電動 機的用途之外’還能夠應用於電動汽車用的驅動電動機的 -11 - 200901601 用途。 【圖式簡單說明】 第1圖爲表示本發明的第1實施例的永磁式無刷電動 機之側面剖面圖。 第2圖爲表示沿著第1圖中的A- A線之電動機的全 體構成之正面剖面圖。 第3圖爲本發明的永磁式無刷電動機所適用的遮蔽板 之側面圖。 第4圖爲將習知的遮蔽板成形爲圓弧狀經展開之側面 圖。 第5圖爲習知的永磁式無刷電動機之側面剖面圖。 第6圖爲表示沿著第5圖中的A - A線之電動機的全 體構成之正面剖面圖。 【主要元件符號說明】 1 :定子鐵心 2 :空心線圈 3 :定子 4 :框架 5 :轉子軛 5 a :鍔部 6 =從動軸 7 :永久磁鐵 -12- 200901601 8 :轉子 9 :迴轉檢測器 1 0 :迴轉盤 1 1 :軸承 1 2 :空隙部 1 3 :遮蔽板 1 4 :切槽 15 :基體 -13-200901601 IX. The present invention relates to a drive motor for an industrial field such as FA (factory automation) or 〇A (office automation), or a drive motor for an electric vehicle, and A permanent magnet type brushless motor including an armature winding formed by winding a plurality of hollow-shaped coils for forming a rotating magnetic field on a stator core, and a permanent magnet mounted on a rotor yoke, in particular, a rotary detector is disposed The noise-resistant structure of the motor with the rotary detector attached to the same space without a bracket or the like. [Prior Art] In the past, it used as a drive motor for industrial fields such as FA or OA, or as a drive motor for electric vehicles in recent years, and has a plurality of hollow-shaped coil packages for forming a rotating magnetic field. For example, a configuration of the armature winding formed in the stator core and the permanent magnet type brushless motor mounted on the permanent magnet of the rotor yoke is proposed. In the permanent magnet type motor of such a configuration, most of the rotary gyro's for detecting the position of the rotor are disposed in another space in which the bracket is used to enter the compartment for the armature winding or the permanent magnet. . Different from the above configuration, 'there is no bracket for the armature winding and the permanent magnet.' The rotary detector is disposed in the same space as the armature winding or the permanent magnet, and the motor with the rotary detector is formed as the first The composition of the 5 figure. Further, Fig. 5 is a side sectional view showing a conventional permanent magnet type brushless motor. Fig. 6 is a front cross-sectional view showing the overall configuration of the electric motor -4-200901601 along the line a - a in Fig. 5. Here, an internal rotor type gap winding motor of 18 poles and 15 coils is taken as an example. In the figure, the figure 1 is the stator core, the figure 2 is the air core coil, and the figure 3 is the stator. Figure 4 is the frame 'Figure 5 is the rotor yoke' Figure 6 is the driven shaft, Figure 7 is the permanent magnet, Figure 8 is the rotor 'Figure 9 is the rotary detector, Figure 10 is the rotary disk, Figure No. 11 is a bearing 'Fig. 12 is a void portion, and Figure 15 is a base. The stator 3 of the permanent magnet motor is a substantially cylindrical stator core 1 formed by laminating a bismuth steel sheet, and is wound at equal intervals: a thin insulating plate for ensuring a desired insulation withstand voltage is wound. The armature winding formed by a plurality of hollow coils 2 is formed. The armature winding is molded or impregnated with a resin and integrally fastened with the stator 1. Further, the loop of the air-core coil 2 is formed by a coil wound by a line. Further, the rotor 8 is a substantially cup-shaped rotor yoke 5 which is concentrically arranged with a magnetic gap therebetween, and a crotch portion 5a attached to the rotor yoke 5 and has a plurality of magnetic poles having different alternating polarities. The permanent magnet 7 is divided into arc-shaped rare earth elements. Then, the rotor 8 is rotatably supported by a bearing 11 that is fitted between the driven shaft 6 and the stator 8 and attached to the inner circumference of the driven shaft 6. Further, the rotary disk 10 is attached to the driven shaft 6 which is a body of the rotor 8, and the rotation detector for detecting the position of the rotary disk is provided in a space portion located inside the crocodile portion of the rotor yoke. Patent Document 1: Japanese Patent Laid-Open No. 2 〇〇 2 _ 1 〇丨 5 9 5 (2nd page, 1st to 2nd drawings in the proposal) 200901601 [Summary of the Invention] <Problems to be Solved by the Invention> As in the Japanese Patent Document 1, the rotation detector 9 is configured to be disposed in another space of the bracket compartment with respect to the air-core coil 2 or the permanent magnet 7, and can be prevented from being affected by the electromagnetic noise from the air-core coil 2. On the contrary, the number of parts increases and the total length becomes longer, so there is a problem that both productivity and cost are deteriorated. Further, as in the technique shown in Fig. 5, the bracket is not used, and the rotation detector 9 is disposed in the same space as the stator coil 1 or the permanent magnet 7, since the distance from the stator coil 1 becomes close, It may be affected by electromagnetic noise or structural components causing FG (frame ground) noise, which may cause problems such as detection of pulse wave jitter and the like. The present invention has been made in view of the above problems, and an object thereof is to provide a permanent magnet type brushless motor which is improved in noise resistance of a rotary detector mounted on a motor, can be miniaturized, and is excellent in productivity, reliability, and cost. . <Means for Solving the Problem> In order to solve the above problems, the present invention is constituted by the following means. The permanent magnet type brushless DC motor according to the first aspect of the present invention is characterized in that: the stator core having a substantially cylindrical shape and a plurality of hollow coils for forming a rotating magnetic field are wound around A stator constituting an armature winding formed by either one of an inner circumference and an outer circumference of the stator core, and a substantially cup-shaped -6-200901601 rotor yoke that is disposed concentrically with the stator and the magnetic gap therebetween And a rotor including a permanent magnet provided with a plurality of magnetic poles having different polarities and a space portion provided inside the flange portion of the rotor yoke, and detecting the position of the rotor The permanent magnet type brushless DC electric motor of the rotary detector is characterized in that a shielding plate is disposed on the stator core, and the shielding plate is a space portion for enclosing the end portion of the hollow coil and the rotor yoke The electromagnetic noise generated from the hollow coil is shielded. The permanent magnet type brushless DC motor according to the second aspect of the invention is the permanent magnet type brushless DC motor according to claim 1, wherein the shielding plate covers the air core coil. The end of the wire is configured such that the end portion of the permanent magnet is bent in a substantially L shape. The permanent magnet type brushless DC motor according to the invention of claim 3, wherein the permanent magnet type brushless DC motor according to claim 1 is in the inner circumference or the outer circumference of the stator core In either case, the frame supporting the stator is provided, and the shielding plate is sandwiched between the stator core and the frame, and FG (frame ground) connection and positioning of the shielding plate are facilitated. The permanent magnet type brushless DC motor according to claim 4, wherein the shielding plate is the same as the permanent magnet type brushless DC motor according to claim 1 or 2 or 3. The sheet material extending in a straight line can be formed into a substantially arc-shaped manner, and has a plurality of slits. The permanent magnet type brushless DC-7-200901601 motor of the present invention is in the fifth aspect of the invention. The permanent magnet type brushless DC motor according to the first aspect of the invention, wherein the dam portion of the rotor yoke extends further in the axial direction than the mounting position of the rotation detecting portion toward the counter load side. The permanent magnet type brushless DC motor according to claim 6 of the invention is the permanent magnet type brushless DC motor according to claim 1 or 5, wherein the crotch portion of the rotor yoke is The end portion on the counter-load side whose wall thickness faces the attachment position of the above-described rotation detector is formed in a push-out shape that becomes larger toward the base on the load side. [Effect of the Invention] According to the permanent magnet type brushless DC motor described in the first aspect of the patent application, since the shielding plate is provided, electromagnetic noise generated by the air-core coil can be prevented from coming to the rotary detector, so even the stator coil The revolving detector can still be configured nearby. According to the permanent magnet type brushless DC motor according to the second and third aspects of the patent application, the cross section of the shielding plate is set to an L shape, sandwiched between the stator core and the frame, and can be positioned even without using screws or the like. At the same time, it can also be connected to FG. Further, the permanent magnet type brushless DC motor according to the fourth aspect of the invention is provided with a slit in which the shielding plate can be formed into an arc shape, so that the shielding plate can be formed in a straight line, and workability and reduction can be improved. cost. In addition, according to the permanent magnet type brushless DC motor described in claim 5, since the end face of the rotor yoke is extended toward the counter load side more than the position of the rotary detector, the rotary detector is Empty-8- 200901601 The electromagnetic noise generated by the heart coil becomes a labyrinth structure, so electromagnetic noise can be greatly suppressed and reliability can be improved. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <First Embodiment> Fig. 1 is a side cross-sectional view showing a permanent magnet type brushless motor according to a first embodiment of the present invention. Fig. 2 is a front cross-sectional view showing the overall configuration of the motor along the line A to A in Fig. 1. Fig. 3 is a side view showing a shield plate to which the permanent magnet type brushless motor of the present invention is applied. Fig. 4 is a side view showing the conventional shield plate formed into an arc shape. Further, this embodiment is an example of an inner rotor type gap winding motor of 18 poles and 15 coils which is the same as the conventional example, and the constituent elements of the present invention are the same as those of the prior art, and the description thereof is Omitted, only for different points. The difference between the present invention and the prior art will be described below. That is, the difference is that the shielding core 13 is disposed in the stator core 1, and the shielding plate is used for the hollow coil from the gap portion 12 surrounded by the coil end portion of the hollow coil 2 and the rotor yoke 5. The generated electromagnetic noise is shielded. The shielding plate 13 is formed so as to be bent in a substantially L shape toward the end portion of the permanent magnet 7 so as to cover the coil end of the hollow wire 2 . Further, on the inner circumference of the stator core 1, a frame -9-200901601 supporting the stator 3 is provided, and a configuration is adopted in which the shielding plate 13 is sandwiched between the stator core 1 and the frame 4, and the FG of the shielding plate 13 is made. (frame ground: frame ground) connection, positioning and fixing becomes easy. The shielding plate has a plurality of slits in which a plate material extending in a straight line shape is formed into a substantially arc shape. Further, the crotch portion 5a of the slewing yoke 5 is more toward the counter load side than the mounting position of the revolving finder 9, and extends in the axial direction. Specifically, it is preferable to use the end portion of the crotch portion 5a. When the length of the rotor yoke 5 fixed to the base portion of the driven shaft 6 in the axial direction is L1, when the length of the axial direction between the attachment position of the rotation detector 9 and the base of the rotor yoke 5 is L2, it becomes L1> The manner of the relationship of L2 defines the axial length of the crotch portion 5a. Further, the flange portion 5a of the slewing yoke 5 is formed so that the thickness of the yoke 5 on the counter load side facing the attachment position of the rotation detector 9 increases, and the base portion of the rotor yoke 5 on the load side becomes larger. Pull out the shape. Next, the action will be described. As described above, the shielding plate 13 having an L-shaped cross-sectional shape is provided between the stator core 1 and the frame 4, and is further extended toward the counter-load side than the mounting position of the rotation detector 9, and the crotch portion of the yoke 5 is extended. 5 a, the electromagnetic noise generated by the hollow coil 2 is shielded by a labyrinth structure formed by the shielding plate 13 bent in the L shape and the crotch portion 5 a of the slewing yoke 5 In this manner, even if the rotary detector 9 is close to the vicinity of the hollow coil, it is not affected by the electromagnetic noise from the air-core coil 2. In addition, when the inner diameter side of the yoke portion 5a of the rotor yoke 5 is improved to a thickness from the end portion on the counter load side toward the base portion on the load side, the power line concentration by the rotor yoke 5 can be prevented. Even if the slewing detection-10-200901601 9 is close to the rotor yoke, it is not affected by the magnetic flux from the rotor yoke 5. Therefore, the embodiment of the present invention is to provide the shielding plate at the coil end portion of the air-core coil and the rotor yoke. The enclosed gap portion extends the end portion of the yoke portion of the rotor yoke toward the counter load side to form a labyrinth structure covering the rotation detector. Therefore, the gap portion between the stator and the rotor can be used to shield the hollow line. The electromagnetic noise emitted by the , can prevent electromagnetic noise from coming to the gyro detector 9, and the reliability is improved. Further, since the rotary detector is disposed in the same space as the air-core coil or the permanent magnet, the motor can be miniaturized. Further, the cross section of the shielding plate may be formed in an L shape, and sandwiched between the stator core and the frame, and can be positioned without using a screw or the like, and connected to the F G at the same time. Further, the shielding plate is formed in a straight line, and the slit which can be formed into a circular arc shape is placed, whereby the workability can be improved and the manufacturing cost can be reduced. As described above, it is possible to obtain a permanent magnet motor with a rotation detector which is excellent in reliability, workability, and cost. [Industrial Applicability] The permanent magnet type brushless motor of the present invention is provided with a shielding plate that is formed so as to be bent in a substantially L shape toward the end portion of the permanent magnet so as to cover the coil end of the air-core coil. The electromagnetic noise generated by the hollow coils is applied to the slewing detector 'because the slewing detector can be disposed even in the vicinity of the stator coils', so it can be applied in addition to the use of the drive motor in the industrial field such as FA or OA. -11 - 200901601 for the drive motor for electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side cross-sectional view showing a permanent magnet type brushless motor according to a first embodiment of the present invention. Fig. 2 is a front sectional view showing the overall configuration of the motor taken along the line A-A in Fig. 1. Fig. 3 is a side view showing a shield plate to which the permanent magnet type brushless motor of the present invention is applied. Fig. 4 is a side view showing the conventional shield plate formed into an arc shape. Fig. 5 is a side sectional view showing a conventional permanent magnet type brushless motor. Fig. 6 is a front sectional view showing the overall configuration of the motor taken along the line A - A in Fig. 5. [Main component symbol description] 1 : Stator core 2 : Air core coil 3 : Stator 4 : Frame 5 : Rotor yoke 5 a : Crotch part 6 = Drive shaft 7 : Permanent magnet -12- 200901601 8 : Rotor 9 : Rotary detector 1 0 : rotary disk 1 1 : bearing 1 2 : clearance portion 1 3 : shielding plate 1 4 : slot 15 : base 13 -