The device is intended to supply a rotating linear displacement actuator capable of controlling the pitch of the blades of a propeller, according to separate operating states, from a rotary power assembly, the device being arranged so as to be located between the power assembly and the actuator, along a longitudinal axis, and being connected in rotation therewith. According to the invention, the device comprises supplies for supplying fluid interacting with the power assembly and defining as many supplies as there are operating states of the actuator, and a fluid distributor to which the supplies are connected and having separate channels for transporting the fluid in the direction of the actuator according to the operating states, by a tubular equipment connected to the distributor.