Husco International, Inc.

Deere & Company

Incova Technologies, Inc.

Eric P Hamkins

Joseph Lawrence Pfaff

Dwight B Stephenson

Corey Quinnell

Jacob Ballweg

Keith A Tabor

Lynn A Russell

Jonathan M Starkey

Raud A Wilke

Curtis Lee Van Weelden

Kristen Dawn Cadman

Edward Aloysius Flynn

Michael C Layne

Steve Gary Fleischmann

Leif Pedersen

Gary J Pieper

Bradley James Kramer

Joe Pfaff

Mark Elton

Jace Birschbach

Casey Buschkopf

Mark Schultz

Darrell Hesse

Todd Michael Murray

Michael Gilling

Kyle Ballweg

A load sense pressure regulating system is provided. The load sense pressure regulating system can be operable between a flow regulation mode and a pressure limiting mode. When the load sense pressure control system is in the flow regulation mode, flow between a load sense inlet and a pilot vent are metered by a main poppet. The load sense pressure regulating system can also include a control valve downstream from the pilot vent that is configured to control a relief setting of a relief valve to regulate the load sense pressure within a desired operating range.

Electronically adjustable pressure compensated flow control with pressure limiting relief valve

A system and method for machinery performing work with hydraulic actuators. Radial hydraulic pumps are aligned end-to-end along a common driveshaft axis to form a multi-pump assembly having a plurality of piston/cylinder units extending in a radial direction. Two or more piston/cylinder units are associated with one another to form multiple piston/cylinder groups. A plurality of control valves combines individual output flows from the two or more associated piston/cylinder units into respective common output flows for each respective piston/cylinder group. A plurality of flow control devices varies the common output flow from each respective piston/cylinder group by throttling inlet flow to the two or more associated piston/cylinder units in each respective piston/cylinder group. Each respective common output flow is directed from each respective piston/cylinder group to a hydraulic actuator on the heavy machinery to control its direction of movement.

Radial piston pump assemblies and use thereof in hydraulic circuits

A hydraulic system and method for using the same are provided. The hydraulic system includes a pump, a first actuator having a first head chamber and a first rod chamber, and a second actuator having a second head chamber and a second rod chamber. The hydraulic system further includes a first control valve and a second control valve. The second control valve to selectively provide regeneration fluid flow from the first rod chamber to the first head chamber in response to a first function command is less than a first function command limit, a second function command is greater than a second function command limit, and a second function load is greater than a second function load limit.

Systems and methods for selectively engaged regeneration of a hydraulic system

A hydraulic control valve assembly to be integrated into a pressure compensated load sensing system including a fluid source is provided. The hydraulic control valve assembly includes a first working unit to control a first hydraulic function of a machine. The first working unit includes a first directional and return flow control in the form of a first spool, a first function flow control to selectively communicate a working pressure of the first function to the fluid source, and a first downstream flow control. The hydraulic control valve assembly further includes a second working unit arranged downstream of the first working unit. The second working unit to control a second hydraulic function of the machine. The first downstream flow control to selectively restrict a flow a fluid from the fluid source to the second working unit.

Metered fluid source connection to downstream functions in PCLS systems

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.

System for allocating fluid from multiple pumps to a plurality of hydraulic functions on a priority basis

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.

Command based method for allocating fluid flow from a plurality of pumps to multiple hydraulic functions

A system has a variable displacement pump that supplies pressurized fluid to power a plurality of hydraulic functions. Each hydraulic function has a control valve with a variable source orifice controlling fluid flow between the pump and a flow summation node, and a variable metering orifice controlling fluid flow between the flow summation node and a hydraulic actuator. Variable bypass orifices in the control valves are connected in series between the flow summation node and a tank. As the metering orifice in a control valve enlarges, the source orifice enlarges and the bypass orifice shrinks. This alters pressure at the flow summation node, which is used to control the output of the pump. Components are provided to give selected hydraulic functions different levels of priority with respect to consuming fluid flow from the pump.

Hydraulic system with fluid flow summation control of a variable displacement pump and priority allocation of fluid flow

A vehicle with a load sensing hydraulic control system is disclosed.

Differential pressure control

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.

Flow summation system for controlling a variable displacement hydraulic pump

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.

Energy recovery and reuse techniques for a hydraulic system

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.

Energy recovery and reuse methods for a hydraulic system

A vibration damper piston includes a piston body with a bore from which first and second apertures respectively provide paths to first and second chambers of the vibration damper. A valve spool in the bore defines a pilot chamber and controls fluid flow between the first and second apertures. First and second springs bias the valve spool in opposing directions. A control orifice provides a continuous fluid path between the first chamber and the pilot chamber, and a variable orifice provides another fluid path between the second chamber and the pilot chamber. An actuator is operably connected to adjust the variable orifice in response to a control signal.

Hydraulic vibration damper piston with an integral electrically operated adjustment valve

A solenoid operated valve has a valve body with a plurality of ports and a spool slidable within the body to interconnect the ports in different combinations. A solenoid, which is coupled to drive the spool, has a coil wound on an annular bobbin with a tube of an electrically conductive, non-magnetic metal within the bobbin. A first pole piece extends into one end of the tube and a second pole piece extends into another end of the tube. A separate bushing is located in an aperture in each pole piece. Each bushing has a tubular body with a first end section that has a larger outer diameter than a second end section and the second end section that has a smaller inner diameter than the first end section. The solenoid further includes an armature that is slidably received in the bushings and engaging the spool.

Electrohydraulic valve for controlling a cam shaft phasing mechanism of an internal combustion engine

A hydraulic fluid is supplied from a tank to a plurality of actuators by a variable displacement pump which produces an output pressure that is a constant amount greater than a pressure at a control input. A mechanism senses the greatest pressure among the workports to provide a first load-dependent pressure and a second load-dependent pressure which is greater than the first load-dependent pressure when the pump operates a maximum flow capacity. Each valve section includes a pressure compensating valve which controls the fluid flow to the associated actuator in response to a pressure differential between the metering orifice and either the first or second load-dependent pressures. When the pump operates at maximum flow capacity, actuators connected to the valve sections in which the pressure compensating valve responds to the first load-dependent pressure receive the fluid flow on a priority basis as compared to the other valve sections. Thus the system operates the priority actuators as normally as possible during a maximum pump flow situation by reducing the fluid flow to non-priority actuators.

Hydraulic control valve system with load sensing priority

An improved pressure-compensated hydraulic system for feeding hydraulic fluid to one or more hydraulic actuators. A remotely located, variable displacement pump provides an output pressure equal to input pressure plus a constant margin. A pressure compensation systems requires that a load-dependent pressure be provided to the pump input through a load sense circuit. A reciprocally spooled, multiported isolator transmits the load-dependent pressure to the pump input but prevents fluid in the load sense circuit from leaving the load sense circuit and flowing through a relatively long conduit leading to the remotely located pump. In a multi-valve array, at least one valve section has a backflow-preventing shuttle valve which prevents backflow through the pressure compensation system if a main relief valve is operative.

Growing community of inventors

Waukesha, WI, United States of America

Eric P Hamkins