A continuously variable automatic transmission comprising: an input shaft arranged so as to receive rotational movement and input torque from a movement source, a mechanical system that converts rotational movement and input torque into a rotational movement with an output torque that is adapted to the load requirements in each circumstance, an external output shaft of the transmission integrated in a mechanical sub-assembly, configured to deliver rotational movement and the torque adapted to the forces required in this output, where the input shaft of the transmission is connected to the input of at least one mechanical subsystem for energy accumulation with controlled output by a control device, this subsystem having its own input and output, the subsystem transforms the rotational movement of the input thereof into elastic potential energy contained in the inside thereof and may deliver the accumulated energy by means of the rotation of the output thereof, the rotation of the output thereof being controlled by a control system, the output shaft of the energy accumulation subsystem with controlled output is connected to the input of a mechanical filtering subsystem and output of the transmission, this subsystem having its own input and output, configured such that it has, connected to its own input, at least a first freewheel device and associated with its own output at least one connection with an inertial mass that accumulates kinetic energy; the output of the subsystem is connected to the output shaft of the transmission, characterized in that the input shaft arranged to receive input rotation and torque from a driving source is coupled to the input of the energy conversion system by means of a second freewheel device housed in the inner portion thereof, in order to transmit the rotational movement only in the charging direction of the energy accumulation system, the input shaft is directly connected through the outer portion thereof to the output element of the transmission through a third freewheel device to transmit movement only in the rotation direction of the output. an input shaft arranged so as to receive rotational movement and input torque from a movement source, a mechanical system that converts rotational movement and input torque into a rotational movement with an output torque that is adapted to the load requirements in each circumstance, an external output shaft of the transmission integrated in a mechanical sub-assembly, configured to deliver rotational movement and the torque adapted to the forces required in this output, where the input shaft of the transmission is connected to the input of at least one mechanical subsystem for energy accumulation with controlled output by a control device, this subsystem having its own input and output, the subsystem transforms the rotational movement of the input thereof into elastic potential energy contained in the inside thereof and may deliver the accumulated energy by means of the rotation of the output thereof, the rotation of the output thereof being controlled by a control system, the output shaft of the energy accumulation subsystem with controlled output is connected to the input of a mechanical filtering subsystem and output of the transmission, this subsystem having its own input and output, configured such that it has, connected to its own input, at least a first freewheel device and associated with its own output at least one connection with an inertial mass that accumulates kinetic energy; the output of the subsystem is connected to the output shaft of the transmission, characterized in that the input shaft arranged to receive input rotation and torque from a driving source is coupled to the input of the energy conversion system by means of a second freewheel device housed in the inner portion thereof, in order to transmit the rotational movement only in the charging direction of the energy accumulation system, the input shaft is directly connected through the outer portion thereof to the output element of the transmission through a third freewheel device to transmit movement only in the rotation direction of the output.