Hydraulic control valve system with pressure compensated flow control

In a hydraulic system having a control valve with variable metering orifice through which hydraulic fluid flows from a pump to an actuator connected to the control valve at a workport, the pump producing an output pressure at an output that is a predefined amount greater than an input pressure at a control port, and the input pressure is determined in response to a pressure at the workport;

• a flow compensator comprising:
• a pressure compensating valve controlling flow of fluid between the variable metering orifice and the workport in response to a differential in pressures acting on opposite first and second sides of the pressure compensating valve, wherein the first side receives a pressure produced by the variable metering orifice;
• and
• a flow regulator valve controlling flow of fluid between the output of the pump and the second side of the pressure compensating valve in response to a pressure from the output of the pump acting to open the flow regulator valve, the pressure at the second side of the pressure compensating valve acting to close the flow regulator valve, and a biasing element that also acts to close the flow regulator valve.

In a hydraulic system having an array of control valve sections for controlling flow of hydraulic fluid from a pump to a plurality of actuators, each control valve section has a workport to which one actuator connects and having a metering orifice through which the hydraulic fluid flows from the pump to the workport, the pump produces an output pressure that is a predefined amount greater than a pressure at a control port, the array of control valve sections being of the type in which the greatest pressure among the workports is sensed to provide a load sense pressure that is transmitted to the control port;

• at least one of the control valve sections having a flow compensator comprising:
• a pressure compensating valve controlling flow of fluid between the variable metering orifice and the workport in response to a differential in pressures acting on opposite first and second sides of the pressure compensating valve, wherein the first side receives a pressure produced by the variable metering orifice;
• and
• a flow regulator valve controlling flow of fluid between the output of the pump and the second side of the pressure compensating valve in response to a pressure from the output of the pump acting on one side of the flow regulator valve, the pressure at the second side of the pressure compensating valve acting on another side of the flow regulator valve, and as biasing element that also acts on the another side of the flow regulator valve.