摘要:
A hydraulic system has a valve assembly with two workports coupled to chambers of first and second cylinders which are connected mechanically in parallel to a machine component. A separation control valve is connected between first chambers of both cylinders, and a shunt control valve is connected between the workports. A recovery control valve couples an accumulator to the first chamber of the second cylinder. Opening and closing the valves in different combinations routes fluid from one or both cylinders into the accumulator where the fluid is stored under pressure, and thereafter enables stored fluid to be used to power one or both cylinders. The shunt control valve is used to route fluid exhausting from one chamber of each cylinder to the other chambers of those cylinders. Thus the hydraulic system recovers and reuses energy in various manners.
摘要:
A method provides several modes for recovering hydraulic energy produced by an overrunning load acting on cylinders connected in parallel to a machine component. In one mode, fluid from first chambers in both cylinders is routed into the accumulator, while other fluid is directed into second chambers of those cylinders. In a different mode, fluid is routed from the first chamber of only one cylinder into the accumulator, and fluid from the first chamber of the other cylinder goes into the second chambers of both cylinders. Yet another mode comprises routing fluid from the first chambers of both cylinders into the second chambers of both cylinders. In still another mode, fluid from the first chambers of both cylinders goes into the return conduit while the second chambers of both cylinders receive fluid from a supply conduit. Several modes of reusing the recovered energy are described.
摘要:
A method provides several modes for recovering hydraulic energy produced by an overrunning load acting on cylinders connected in parallel to a machine component. In one mode, fluid from first chambers in both cylinders is routed into the accumulator, while other fluid is directed into second chambers of those cylinders. In a different mode, fluid is routed from the first chamber of only one cylinder into the accumulator, and fluid from the first chamber of the other cylinder goes into the second chambers of both cylinders. Yet another mode comprises routing fluid from the first chambers of both cylinders into the second chambers of both cylinders. In still another mode, fluid from the first chambers of both cylinders goes into the return conduit while the second chambers of both cylinders receive fluid from a supply conduit. Several modes of reusing the recovered energy are described.
摘要:
A hydraulic system has a valve assembly with two workports coupled to chambers of first and second cylinders which are connected mechanically in parallel to a machine component. A separation control valve is connected between first chambers of both cylinders, and a shunt control valve is connected between the workports. A recovery control valve couples an accumulator to the first chamber of the second cylinder. Opening and closing the valves in different combinations routes fluid from one or both cylinders into the accumulator where the fluid is stored under pressure, and thereafter enables stored fluid to be used to power one or both cylinders. The shunt control valve is used to route fluid exhausting from one chamber of each cylinder to the other chambers of those cylinders. Thus the hydraulic system recovers and reuses energy in various manners.
摘要:
A valve assembly controls fluid flow between first and second ports of a hydraulic actuator and each of a supply line and a return line. A first electrohydraulic proportional valve is connected between the supply line and the first port, and second electrohydraulic proportional valve is connected between the supply line and the second port. A first counterbalance valve couples the second port to the return line and operates in response to pressure created by the first electrohydraulic proportional valve and the first port. A second counterbalance valve couples the first port to the return line and operates in response to pressure created by the second electrohydraulic proportional valve and the second port. Thus operation of the first counterbalance valve is slaved to the first electrohydraulic proportional valve, and the second counterbalance valve is slaved to the second electrohydraulic proportional valve.
摘要:
A valve assembly has a flow summation node coupled to a displacement control port of the first pump. Each valve in the assembly has a variable metering orifice controlling flow from an inlet to a hydraulic actuator and has a variable source orifice conveying fluid from a supply conduit to a flow summation node. The source orifice enlarges as the metering orifice shrinks. Each valve includes a variable bypass orifice and the bypass orifices of all the control valves are connected in series forming a bypass passage between a bypass node and a tank. The bypass node is coupled to the flow summation node and receives fluid from a second pump. At each valve, a source check valve conveys fluid from the supply conduit to the inlet and a bypass supply check valve conveys fluid from the bypass passage to the inlet.
摘要:
A valve assembly couples a plurality of hydraulic actuators to a variable displacement pump and to a tank. A separate valve is associated with each hydraulic actuator and comprises a variable flow source orifice between the supply conduit and a summation node coupled to a pump control port, a variable metering orifice between the summation node and the associated hydraulic actuator, and a variable bypass orifice between the summation node and the tank. As a valve operates to enlarge the metering orifice, the flow source orifice also enlarges, and the bypass orifice shrinks. When the valve operates to shrink the metering orifice, the flow source orifice also shrinks and the bypass orifice enlarges. Those operations vary fluid flow in and out of the summation node, which alters pressure applied to the pump control, thereby causing the pump output to vary as required to drive the associated hydraulic actuator.
摘要:
A valve assembly has a flow summation node coupled to a displacement control port of the first pump. Each valve in the assembly has a variable metering orifice controlling flow from an inlet to a hydraulic actuator and has a variable source orifice conveying fluid from a supply conduit to a flow summation node. The source orifice enlarges as the metering orifice shrinks. Each valve includes a variable bypass orifice and the bypass orifices of all the control valves are connected in series forming a bypass passage between a bypass node and a tank. The bypass node is coupled to the flow summation node and receives fluid from a second pump. At each valve, a source check valve conveys fluid from the supply conduit to the inlet and a bypass supply check valve conveys fluid from the bypass passage to the inlet.
摘要:
Fluid from two pumps is allocated to a plurality of hydraulic actuators based on a plurality of flow commands, each specifying a desired amount of flow to be applied to a different hydraulic actuator. For a given hydraulic actuator, the allocation involves (1) determining an apportionment of the desired amount of flow, if no other hydraulic actuator is active, and (2) altering the apportionment in response to all the plurality of flow commands, and (3) using the altered apportionment to determine a first amount of the flow for one pump to provide and a second amount of the flow for the other pump to provide. The process is repeated for all the hydraulic actuators. Supply valves for each hydraulic actuator are controlled by the associated first and second amounts and each pump is controlled in response to either the first or second amounts for all the hydraulic actuators.
摘要:
Fluid from two pumps is allocated to a plurality of hydraulic actuators based on a plurality of flow commands, each specifying a desired amount of flow to be applied to a different hydraulic actuator. For a given hydraulic actuator, the allocation involves (1) determining an apportionment of the desired amount of flow, if no other hydraulic actuator is active, and (2) altering the apportionment in response to all the plurality of flow commands, and (3) using the altered apportionment to determine a first amount of the flow for one pump to provide and a second amount of the flow for the other pump to provide. The process is repeated for all the hydraulic actuators. Supply valves for each hydraulic actuator are controlled by the associated first and second amounts and each pump is controlled in response to either the first or second amounts for all the hydraulic actuators.