Magnetic Lead Screw – 磁気式送りねじ

Development of a Magnetic Lead Screw (MLS) and an MLS driven Linear Actuator

Force-controllable actuators are essential for guaranteeing safety in human-robot interactions. Magnetic lead screws (MLSs) transfer force without requiring contact between parts. These devices can drive the parts with high efficiency and no frictional contact, and they are force limited when overloaded. We have developed a novel MLS that does not include spiral permanent magnets and an MLS-driven linear actuator (MLSDLA) that uses this device. This simple structure reduces the overall size of the device and improves productivity because it is constructed by a commonly used machined screw as a screw. The actuator can drive back against an external force and it moves flexibly based on the magnetic spring effect.




  1. 松岡,酒井, 仲田, 新口, 石黒, 平田, “螺旋型磁石を用いない磁気ねじアクチュエータの提案,” 日本AEM学会誌, vol.25, no.2, pp.224-229, 25th Jul., 2017.
  2. A. Heya, Y. Nakata, M. Sakai, H. Ishiguro, K. Hirata, “Force Estimation Method for a Magnetic Lead-Screw-Driven Linear Actuator,” IEEE Transactions on Magnetics, 2018. DOI: 10.1109/TMAG.2018.2845455


  1. 仲田, 酒井, 平田, (学生補助:部矢), “新コンセプトの小型磁気ねじを使ってみませんか?,” イノベーションジャパン2018, 東京ビッグサイト, 30th – 31th Aug., 2018. Link