超磁わい材料を用いたダイレクトドライブ油圧サーボバルブの開発

抄録

A nozzle-flapper-type servovalve has good characteristics (high response, compact design, low power consumption), and is thus used in many applications, e. g., aeroplanes and test machines. However, this type of servovalve needs first-stage flow which causes leakage, and the user should take care to keep contamination levels low. For these reasons, the need for direct-drive servovalves (DDV) is increasing. The DDV does not have first-stage flow and is not influenced by contamination. In this paper, we present a new DDV using a giant magnetostrictive material. Using this material, we can develop a high-performance DDV, i. e., with high output power, high response and high resistance to environmental factors (e. g., humidity, oil, etc).