Set of swashplates for controlling the pitch of rotor blades, a rotor and an aircraft having such a set

A set of swashplates for controlling the pitch of blades of a rotor, said set being provided with a non-rotary swashplate held against any rotation about an axis of rotation and a rotary swashplate suitable for rotating about the axis of rotation, the set including drive means for constraining the rotary swashplate and a rotor mast of the rotor in rotation about the axis of rotation, the drive means being provided with a drive arm driving rotation of the rotary swashplate about the axis of rotation, the drive arm extending in elevation from a first end towards a second end that is to be fastened to a rotor mast, wherein the drive arm drives rotation of the rotary swashplate about the axis of rotation by means of a plane connection including a fork, the first portion being held captive laterally between two lateral branches of the fork, the fork being hinged to the rotary swashplate by movement means giving the rotary swashplate a degree of freedom to move in rotation about a radial direction of the rotary swashplate relative to the fork.