Hydraulic pressure intensifier D8.757 series

An oscillating pump piston, that will be automatically reversed in the end positions by a hydraulically-operated valve, is installed in the intensifier. The ratio of the piston areas corresponds to the intensification ratio. For unhindered flow in the low-pressure range, the pump piston will be bypassed by means of a bypass-line. A pilot-controlled check valve shuts off the high pressure. Functional principle The flow rate is supplied without pressure through input IN via the check valves RV3 and DV2 to the output H and thereby to the hydraulic cylinders. At the same time, the oscillating pump OP starts working. The flow rate at output H is getting smaller and smaller and is nearly zero when reaching the maximum operating pressure. The pump holds constant the pressure at H as long as low-pressure is available at IN. Between the ports IN and R there will be leakage of approx. 50 cm3/min, since due to functional reasons the pump elements cannot be sealed without leakage. If the input IN is depressurised, the check valve DV2 prevents a pressure drop at port H. To retract the cylinders, port IN will be depressurised and port R pressurised. The check valves DV1 and DV2 will be unlocked and allow a free return. Single-acting cylinders If only single-acting cylinders are connected, a double-acting valve function is required to control the pilot-operated check valves for unclamping (see hydraulic circuit diagram).