由於空間的限制，磁懸浮之小型軸流式泵通常只含有一組主動式磁力軸承做轉子軸向位移控制，徑向則以兩組被動式磁力軸承平衡。因為只有軸向有控制，轉子於高速運轉時易產生徑向振盪。為改善轉子振盪問題，本論文提出一新型之主動式磁力軸承用的電磁鐵，此電磁鐵含有四個電流單獨控制之極，若在各極加上適當的電流則電磁鐵除了可產生軸向力外，亦可以產生相當明顯可以控制的徑向力，此徑向力可用來抑制轉子徑向振盪。此外，本論文亦提出一利用六顆單軸霍爾感測元件來量測轉子之軸向及徑向位移之方法，因為使用霍爾感測元件，故量測系統所占空間小，極適合用於小型軸流式泵。除了以理論及有限元素方法分析提出的方法之外，本論文亦包含實驗結果以驗證提出之方法的可行性。 Due to the space limitations, miniature magnetically levitated axial flow pump usually has an active magnetic bearing for rotor axial direction control, and two passive magnetic bearings to balance the radial directions. Since only the axial direction is controlled, rotor is oscillatory in the radial directions. This thesis proposed a new electromagnetic actuator for axial direction control to reduce rotor oscillations. The actuator has four independently controlled poles. When the poles are properly excited, the actuator can produce controllable axial as well as radial forces. In addition, a method which uses six Hall-effect sensors to measure rotor axial and radial displacements is also proposed. The measurement system requires very small space since Hall sensors are used. Therefore, it is suitable for miniature axial flow pump applications. Besides theoretical and finite-element analysis, experimental verifications of the proposed methods are also included in this thesis.
