COMBINED-ACTION PISTON STEPPED HYDRAULIC DRIVE Russian patent published in 2001 - IPC

FIELD: underwater shipbuilding. SUBSTANCE: the hydraulic drive has two double-cavity hydraulic motors with piston and rod cavities communicating through a controllable hydraulic control valve with pressure and drain lines installed for coming to a single phase in the extreme positions of the hydraulic drive, at least one hydraulic motor is installed on a fixed base for tight coupling to the other hydraulic motor. The unlike cavities of the hydraulic motors are hydraulically coupled in pairs and make up two combined cavities fed by two hydraulic lines only. In the extended position of the pistons the combined cavities are connected to the pressure line, and in the extended position of the piston of the hydraulic motor connected to the pressure line is the combined cavity formed by the piston cavity corresponding to it, and the other combined cavity is connected to the drain line. EFFECT: reduced quantity of the hydraulic lines connecting the hydraulic control valves to the users, enhanced efficiency of the drive at an emergency de-energizing. 2 cl, 1 dwg