｜應用於電動自行車之軸向磁通馬達設計發展

摘要：本文主要針對工研院應用在電動自行車的超薄型馬達進行設計分析，藉由研製、測試驗證馬達特性。工研院採用軸向磁通馬達設計以達到馬達超薄化，並透過解決機構上如結構強度與磁鐵吸力等問題，完成厚度僅37.6 mm輕量化直驅馬達，使電動自行車馬達相較傳統更輕薄。本文先比較軸向與徑向磁通馬達的特性差異，以BionX馬達作為標竿分析，定義設計規格。在馬達設計的過程中，進行電磁設計分析及解決軸向磁通馬達在機構上的問題，最終研製雛型並進行測試驗證。

Abstract: This paper presents an e-bike slim motor designed and analyzed by ITRI. The performance of the slim motor is tested and verified. To minimize the thickness of the motor, axial-flux motor design is chosen.  The mechanism problem like structure stiffness and magnet force has been carefully analyzed. A 37.6 mm thickness lightweight slim motor has been developed and tested.  It demonstrates that the design by ITRI can be thinner and lighter than traditional radius-flux e-bike motor.  In this paper, firstly, the difference between radius flux motor and axial flux motor are discussed. Secondly, the specifications of an ITRI slim motor are defined after benchmarking a BionX e-bike motor.  At the end of the paper, the ITRI e-bike motor designed according to the specifications is manufactured and verified accordingly.

關鍵詞：電動自行車、電動助力自行車、軸向磁通馬達

Keywords：E-bike, Pdelec, Axial flux motor

前言
電動馬達是現今文明世界中使用最多、隨處可見的動力元件，隨著溫室氣體減量及科技綠能化的要求下，以電動馬達驅動的電動車已是當今車輛產業最熱門的研發領域之一。在過往電動車發展初期，各廠商是以工業應用成熟的徑向磁通永磁與感應馬達等為基礎，發展車用動力馬達。同樣的，隨著薄、輕、高效率等產品精緻化需求，以相較徑向磁通馬達有較大磁通面積的軸向磁通馬達設計輕、薄、高扭力密度的盤型馬達，逐漸受到大家的重視而加以探討。本文即在分享說明工研院機械所研發之電動助力自行車用軸向磁通馬達研發成果及其關鍵技術。