1. A method of operating a forage harvester for harvesting agricultural products provided with a replaceable unit, e.g., pickup or corn attachment and equipped with shredding blades (29) crushing drum (1), to which the direction (30) of the flow of crop material mounted hydrostatically driven rollers podpressovyvayuschie (2, 2 , 3, 3), wherein the hydrostatic drive comprises a motor (13) and hydraulic pump (12) kinematically coupled with the mechanical milling drum drive (1), characterized in that a hydraulic pump (12) can be used, on the one hand, as the hydrostatic pressure source for the hydraulic motor (13) for driving podpressovyvayuschih rollers (2, 2 , 3, 3) and, on the other hand, as a motor for the reverse driving milling drum (1) .2. An apparatus for carrying out the method according to claim 1, characterized in that the hydraulic pump (12) is adapted to use, on the one hand, as the hydrostatic pressure source for the hydraulic motor (13) for driving podpressovyvayuschih rollers (2, 2 , 3, 3 & apos ) and, on the other hand, as the drive motor to reverse the milling drum (1) .3. The apparatus according to claim 2, characterized in that the reverse process can be used for resharpening grinding blades (29) by means of a grinding device (33) .4. The apparatus according to claim 2, characterized in that the hydraulic pump of the hydraulic control system (12) is arranged to switch so that, on the one hand, in closed loop hydrostatic it can drive the hydraulic motor (13) for driving podpressovyvayuschih rollers (2, 2 , 3, 3) and, on the other hand, in an open loop it1. Способ эксплуатации полевого измельчителя для уборки сельскохозяйственной продукции, снабженного сменным аппаратом, например, подборщиком или кукурузной приставкой, и оснащенным измельчительными ножами (29) измельчительным барабаном (1), перед которым по направлению (30) потока убранной массы установлены приводимые гидростатически подпрессовывающие валики (2, 2, 3, 3), причем гидростатический приво
