Arm is rolled over with gyration in flexible joint

The utility model provides a flexible joint, the capacitor has a first end and a second end, first end connects in articulated portion with the second end hinge, articulated portion has at least one articulated shaft, the articulated shaft articulated and form cordwood system articulated relation step by step in proper order, it connects on the articulated shaft to pass dynamic wheel group, firstdrive wheel and secondary drive wheel with articulated shaft axial direction parallel have, first drive wheel has first tensioning face, the secondary drive wheel has second tensioning face, but the flexible element tensioning of connecting the first arm and second arm is on first tensioning face and/or second tensioning face, a gyration arm, includes the first arm, second arm, flexible element and flexible joint: the first arm is connected through flexible joint with the second arm, is equipped with first leading wheel on the first arm, is equipped with the second leading wheel on the secondarm, the flexible element