LOAD SENSING HYDRAULIC CIRCUIT HAVING POWER MATCHING MEANS

摘要

A load sensitive hydraulic circuit for material handling equipment is energized by a prime mover. The hydraulic circuit includes variable displacement pumps coupled to the prime mover and having pressure and flow compensating control means for varying the volumetric output. Each pump is connected to a valve bank which controls various hydraulic actuators of the material handling equipment. Load pressure feedback is provided to the pump compensators for etablishing pump flows to operate the actuators at a fixed pressure differential in excess of load pressure. The valve banks contain pressure compensated valves for providing desired fluid flow rates and speeds in the hydraulic actuators. Means are provided to sense reductions in the prime mover speed resulting from excessive hydraulic loads. The means is connected to the pump compensators for simultaneously adjusting the volumetric output of the hydraulic pumps at the preselected pressure differential over the load pressure and power demands on the prime mover so that demands on the prime mover are matched to its available power output.