The present invention provides a flexible actuator, a robot joint, a robot, and an exoskeleton robot that can be flexibly driven to an execution mechanism by a small structure and highly reliable transmission. A flexible actuator according to the present invention includes a drive mechanism, a transmission mechanism, and an output mechanism. The transmission mechanism includes a main rotation member, a driven rotation member, and a rope that form a rope transmission relationship. The rope is wound around the rotational surfaces of the main rotating member and the driven rotating member, the rotation center axis of the main rotating member is orthogonal to the rotation center axis of the driven rotating member, and the output end of the drive mechanism is the main rotating member. The output mechanism includes a flexible driving member 31 and an output member 32 for connecting to an external execution member, and the driven rotating member is connected to the output member by the flexible driving member. To drive the rotation. [Selection] Figure 1【課題】本発明は、小型の構造及び信頼性の高い伝達性によって実行機構へのフレキシブル駆動が図られるフレキシブルアクチュエータ、ロボット関節、ロボット及び外骨格ロボットを提供する。【解決手段】本発明に係るフレキシブルアクチュエータは、駆動機構１０、伝達機構２０及び出力機構３０を含み、伝達機構２０は、ロープ伝達関係を形成する主動回転部材２１、従動回転部材２２及びロープ２３を含み、ロープが、主動回転部材及び従動回転部材の回転表面に巻き付けられ、主動回転部材の回転中心軸が、従動回転部材の回転中心軸と直交し、駆動機構の出力端は、主動回転部材の回動を駆動させるように主動回転部材と接続され、出力機構は、フレキシブル駆動部材３１と、外部実行部材と接続するための出力部材３２とを含み、従動回転部材が、フレキシブル駆動部材によって出力部材の回動を駆動する。【選択図】図１
