1. Braking system for a rotating chopping drum (14) of a forage harvester (10) driven by an engine (11) by means of a drive mechanism comprising a disconnecting clutch (21) and also driving a first pump (28) connected to the drum and pumping fluid along the hydraulic circuit, including an opening limiter (40) and an engine (29) driven by the first pump, driving the rollers (18) of the forage harvester, feeding plants to the chopping drum made with the possibility of braking the grinding drum (14) by disconnecting the coupling (21) and controlling the first pump (28) to pump fluid along the circuit through the open stop (40) when the drum continues to rotate, in order to convert the energy of its rotation into heat so that when disconnected couplings (21), the flow of fluid from the first pump (28) to the feed roll engine (29) was stopped, and the fluid pumped along the circuit by the first pump was diverted through the opening stop (40) .2. The system according to claim 1, in which the fluid supply from the first pump (28) to the feed roller engine is stopped by means of an electromagnetic on-off valve (37) for pressure relief directing the fluid flow from the first pump to the system collector (38) through the restrictor (45) and thus actuating the bypass valve (39) with servo control to divert the main stream from the first pump through an openable restrictor (40) .3. The system according to claim 1, in which, when the coupling (21) is disconnected, the charge pressure of the first pump (28) is maintained by the charge pressure of the second pump (35),1. Система торможения вращающегося измельчающего барабана (14) силосоуборочного комбайна (10), приводимого в движение двигателем (11) с помощью приводного механизма, содержащего разъединительную муфту (21) и также приводящего в действие первый насос (28), соединенный с барабаном и перекачивающий жидкость по гидравлическому контуру, включающему в себя открываемый ограничитель (40) и приводимый в действие первым насосо
