HYDRAULIC DRIVE FOR WEIGHING-OUT AND LEVELLING CARGO PLATFORM Russian patent published in 1999 - IPC

FIELD: mechanical engineering; hydraulic drives; hoisting-and-conveying machinery for weighing-out (raising) and levelling cargo platforms and self-propelled units located on stationary flats. SUBSTANCE: hydraulic drive includes two pairs of hydraulic supports, supply source, first flow divider, three-position levelling distributors and controllable check valves. Hydraulic supports are mounted in corners of platform. Supply source is connected with piston and rod chambers of hydraulic supports by means of mains. First flow divider connects the supply source with piston chambers of pair of adjacent hydraulic supports. Above-valve chambers of valves are brought in communication with piston chambers of hydraulic supports. Drive includes also twin pumps-motors and throttling device for connecting the pumps-motors with tank. Each pump-motor is connected with rod chambers of controllable check valves. Above-valve chambers of check valves are brought in communication with piston chambers of one pair of hydraulic supports located diagonally. Three-position levelling distributors are made in form of two four-line spool valves whose inlet holes are connected with supply source and outlet holes are connected with tank. Outlet holes of each spool valve are connected with rod chambers of respective pair of hydraulic supports located diagonally and with piston chambers of controllable check valves. Above-valve chambers of check valves are brought into communication with piston chambers of hydraulic supports. EFFECT: enhanced reliability of hydraulic drive. 5 cl, 2 dwg