The invention describes a device for winding/unwinding a link, comprising:



an input shaft (10) and a hollow through output shaft (20), the two shafts being coaxial and movable in rotation about a longitudinal axis (L),
a permanent magnet synchronous motor (30) comprising a rotor (31) integral in rotation with the input shaft (10),
a cycloidal reducer (50) comprising an eccentric cam (51) mounted integral in rotation with the input shaft (10), and a cycloidal disc (52) mounted integral in rotation with the cam (51), in such a way that a rotation of the cam (51) about the longitudinal axis (L) drives a rotation of the cycloidal disc (52) in an eccentric and cycloidal movement, and
a transmission member (60) suitable for transmitting an angular displacement of the cycloidal disc (52) to the output shaft (20).