Patent attributes
The invention relates to a hydraulic drive, especially for two-cylinder thick matter pumps. Said hydraulic drive comprises at least one main pump (10) embodied as a hydraulic variable displacement pump, and two hydraulically actuatable drive cylinders (20, 22) that are each connected to a connection line (16, 18) of the main pump (10) by means of pump connections mounted on one end thereof, forming a closed hydraulic circuit, and communicate with each other at the ends thereof opposing the pump connections (24, 26) by means of a swinging oil line (28). The hydraulic drive also comprises a feed pump (42), by which means pressurized oil is fed from an oil tank to the current low-pressure side into the hydraulic circuit, and a flushing branch (52), by which means a flushing oil flow is branched off from the current low-pressure side under a limited pressure into the oil tank (44). In order to avoid low-pressure influxes during the reversal process of the main pump (10), the flushing oil flow is blocked and then released in a time-delayed manner during each reversal process of the main pump (10), independently of the differential pressure in the connection lines.
