隨著科技進步，馬達在各項產業的應用上日益增加，其中永磁無刷馬達在設計以及材料技術進步之下，價格已經可以與有刷馬達相提並論，且由於永磁無刷馬達有著低噪音、低摩擦、低維修費、無火花、高效率、高功率密度以及高加速性等多項優點，使其在近年工業自動化的需求下而蓬勃發展，也使得伺服馬達的發展更顯重要。
工業用馬達發展至今，由於各種機台的體積以及安裝空間的壓縮，故終端使用者對於伺服馬達小體積的要求越來越高，而導致馬達功率密度之提升。在功率密度提升的前提下，馬達本體溫度逐漸地上升，對於馬達各零組件的壽命以及可靠度會是嚴苛的挑戰;以搭配光學位置感測器的高精度伺服馬達來說，位置感測器內部LED是耐溫最低的元件，因此在現行伺服馬達設計趨勢下，如何最經濟且有效的降低LED溫度是當前的重要課題。

The servo motor is widely used in many fields and plays an important role in industrial automation. The servo motor is being asked to reduce its volume, resulting in increased servo motor power density. In order to obtain high motion accuracy, the servo motor must use an optical position sensor (encoder) in which an LED is usually employed. Hence, the LED inside the encoder is the weakest part of the high accuracy servo motor. So we want to reduce the LED temperature to increase servo motor life. By using CAE software we can analyse the temperature distribution of the servo motor. As the fin is the simplest method to remove heat dissipation, we use finite element software to optimize the temperature of motor by fin design.
The surface of the motor frame is the largest pathway for heat transfer to the surrounding while the rear-bracket is the component closest to the LED. Therefore, we add fins to the frame and the rear-bracket individually. When we design the rear-bracket with fin, the temperature has no significant change. However, after adding a fin to the frame surface, the temperature drops about 22~25℃. By this design, we can reduce temperature by 22~25℃ as compared with the original model.

參考文獻
[1]G. M. Rosenberry, “The Transient Stalled Temperature Rise of Cast-Aluminum Squirrel-Cage Rotors for Induction Motors,” AIEE Transactions, Vol. PAS-74, October 1955.
[2]T. J. Roberts, “The Solution of the Heat flow Equations in Large Electrical Machines,” Proceedings Industry Mechanical Engineer, Vol. 184. pt 3E, pp. 70-83, 1970.
[3]B. Yang, “Development of Thermal Models for Permanent-Magnet Traction Motors” Master of Science Thesis in Electrical Machines and Power Electronics at the School of Electrical Engineering Royal Institute of Technology Stockholm, Sweden, 2009.
[4]Y. Huai, V.N. Melnik , P. B. Thogersen,“Computational analysis of temperature rise phenomena in electric induction motors” Technical University of Darmstadt, Energie- und Kraftwerkstechnik, Petersenstraße 30, 64287 Darmstadt, Germany b Faculty of Science and Engineering, Mads Clausen Institute, University of Southern Denmark, Grundvigs Alle 150, Sonderborg, DK-6400, Denmark c Danfoss Drives A/S, Denmark Received 12 October 2002; accepted 20 December 2002.
[5]Y. Cui, G. Wu, G. Gao, Y. Luo, K. Cao, “Analysis and Calculation of Three-dimensional Temperature Field of Inverter-fed Traction Motor” School of Electrical Engineering, Southwest Jiaotong University Chengdu, China, 2012.
[6]O. Craiu, A. Machedon, T. Tudorache, M. Morega, “3D Finite Element Thermal Analysis of a Small Power PM DC Motor” University Politehnica of Bucharest, Faculty of Electrical Engineering, 2010.
[7]張仁豪，“永磁式直流無刷馬達熱流場之數值研究” 國立屏東科技大學 ，車輛工程系，碩士論文， 2010年。
[8]李冠賢，“垂直放置鰭片之自然對流熱傳性能實驗研究” 國立中央大學，機械工程系，碩士論文，2010年。
[9]黃繼震，“馬達控制系統的原理與應用” 中華民國職業訓練研究發展中心，訓練教材，2001年。
[10]郭明珠，“類神經網路於切換式磁阻馬達轉矩漣波控制之 應用” 國立中央大學，電機工程學系，碩士論文，2000年。
[11]高清芬，“旋轉編碼器之原理” 明道大學。
[12]M. J. Caruso and T. Bratland, “A New
Perspective on Magnetic Field Sensing” Honeywell, Inc.
[13]“Applications of Magnetic Position Sensors” Honeywell, Inc.
[14]Nidec, Inc.，http://www.nidec.com/en-NA/technology/rd/resolver/
[15]林俊廷， “汽車頭燈流場分析” 國立成功大學，工程科學系，碩士論文，2009年。
[16]Wekipedia，http://zh.wikipedia.org/wiki/%E9%9B%BB%E6%84%9F
[17]Dr. Duane Hanselman, "Brushless Permanent Magnet Motor Design", Electrical and Computer Engineering University of Maine Orono, 2006.
[18]蔡文昌， “高頻正弦電壓供應下非方向性電磁矽鋼片鐵損量測與評估分析” 高苑科技大學，電機系學報，2008年。
[19]劉益勝，“筆記型電腦可攜式電源供應器之散熱分析”中原大學，機械工程學系，碩士論文，2007年。