WINCH HYDRAULIC DRIVE Russian patent published in 2003 - IPC

FIELD: load handling facilities; crane winches. SUBSTANCE: hydraulic drive has reversible hydraulic motor with load lifting and lowering mains connected with crane hydraulic system by means of three-position distributor hydraulically controlled by remote control unit. Control mains of three position distributor are coupled through logic OR-OR valve with winch brake control mains, brake valve is installed in lifting mains in parallel with check valve, and tank is connected by drain mains with hydraulic motor. Hydraulic drive has two hydraulically controlled normally closed valves , one of which is installed in which brake control mains in parallel with check valve, and its control space is placed in communication through choke with lifting mains between hydraulic motor and brake valve. Other valve is installed in mains connecting lowering mains with brake valve control space, and control space of said valve is connected with winch brake control mains between said first hydraulically controlled normally closed valve and brake release mechanisms. Lifting mains between hydraulic motor and brake valve is connected through choke and check valve with lowering mains, and brake valve control space is coupled through choke with corresponding drain mains. EFFECT: provision of automatic disconnection of winch mechanism in case of breaks in mains laid to winch. 1 dwg