The system has versatile hydraulic motors (1, 2) i.e. radial piston hydraulic motors, with a motor part (Va1) connected in series with hydraulic motors (3, 4) and another motor part (Va2) connected to a pump (P1) so that the motors (3, 4) are surrounded in derivation by oil circulation. A control connection generates partial volume from an inlet channel (A1) until an activator i.e. valve stem device, controls actuating mode, such that the activator closes the part (Va2) and the motors (1, 2) function with partial rotating volume when the channel pressure falls under a critical certain value.
