Hydraulic transmission device allowing the recovery of energy

The device (10) has a fluid accumulator (22) to store and deliver pressurized fluid. A hydraulic motor (16) acts as a hydraulic pump (20) conveying the fluid in the accumulator in an energy recovery mode. The motor is driven by the fluid delivered by the pump in a driving mode. The pump supplies the motor with the fluid collected from a high-pressure-less reservoir in the driving mode. The motor is supplied with the fluid by the pump withdrawing the fluid from the reservoir in the energy recovery mode. An independent claim is also included for an assembly comprising a transmission device, a shaft and a mass.