Parker-hannifin Corporation

Parker Hannifin Emea S.a.r.l.

Björn Eriksson

Ralf Gomm

Randall Denman Thompson

Vivek Bhaskar

Martin Ekstrand

Hans Bodén

The present disclosure relates to a hydraulic valve arrangement comprising a first pilot operated proportional directional control valve having a first valve member that is displaceable in a first and a second axial direction for controlling direction of supply and discharge of hydraulic fluid to and from a hydraulic actuator, a first proportional electro-hydraulic control valve for controlling displacement of the first valve member in the first axial direction, a second proportional electro-hydraulic control valve for controlling displacement of the first valve member in the second axial direction, and a second pilot operated proportional control valve having a second valve member configured to be controlled by the first and second proportional electro-hydraulic control valves via a shuttle valve arrangement. Individual meter-in and meter-out control of the hydraulic actuator is providable by having the second pilot operated proportional control valve configured to operate as a meter-in valve of the hydraulic actuator and the first pilot operated proportional directional control valve configured to operate as a meter-out valve of the hydraulic actuator, or by having the first pilot operated proportional directional control valve configured to operate as a meter-in valve of the hydraulic actuator and the second pilot operated proportional control valve configured to operate as a meter-out valve of the hydraulic actuator. The present disclosure also relates to a vehicle comprising a hydraulic actuator and a hydraulic valve arrangement for controlling the motion of the hydraulic actuator.

Hydraulic valve arrangement

A hydraulic system includes one or more hydraulic subsystems that have a source of additional flow for supplying an auxiliary system. The hydraulic system may include one or more actuator systems, a boost system, and a further hydraulic system, such as a steering system. The source of additional flow for supplying the auxiliary system may include: sizing the boost system for providing both full boost function and auxiliary function, sizing the steering system for providing both full steering function and auxiliary function, utilizing available flow from an unused actuator function, and/or utilizing a selector manifold for actively selecting the source of auxiliary flow based on the flow and pressure demands of the respective hydraulic systems. Such a hydraulic system enables flow to be available to an auxiliary function regardless of the flow requirements for the actuator functions and/or other vehicle functions, while also minimizing interactions and flow disruptions to the various hydraulic subsystems.

Auxiliary system for vehicle implements

Provided is a system and method to generate and control hydraulic fluid flow that exceeds the fluid flow capacity of an electrically driven pump to achieve high actuator retraction/extension speeds and/or electrical flow capacity of an electrical storage system to better control electrical storage. Electric machines and hydraulic pumps generally have a maximum speed beyond which they cannot be operated at. Further, electrical storage systems typically have storage capacities and rates beyond which they cannot be operated at. While an alternate approach could be to increase the hydraulic pump displacement, thus lowering the required electric machine and pump speed to generate a certain flow, it is typically desirable to reduce pump displacement in order to reduce required electric machine torque and minimize component size and losses.

Method of increasing electro-hydrostatic actuator piston velocity

Presented is a system and method to control hydraulic fluid flow, more specifically throttle hydraulic fluid flow, to achieve actuator deceleration rates greater than the maximum deceleration rate of an electrically driven pump. Electric machines and electric machine inverters generally have a maximum torque and current limit beyond which they cannot be operated at. To decelerate a large inertia load for example, high electric machine torque and inverter current are required to provide the braking torque, opposing the fluid flow and pressure generated by the load and hydraulic system.

Electro-hydrostatic actuator deceleration rate control system

A pressure controlling valve includes a slidable spool arranged to be spring loaded towards a neutral position. A first port and a second port are connected to allow a fluid flow through the valve. A first and a second pilot port are connected to a cavity adjacent a respective first and second end surface of the spool. The pilot ports are connected to a fluid conduit on either side of a fluid device causing a pressure drop in the fluid conduit and the fluid device is connected to one of the first or second ports. The spool is displaced against the spring load in response to a pressure difference between the first and the second pilot port, whereby a control surface of the spool is arranged to restrict the fluid flow through the valve when the control surface approaches a central cavity.

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Johanneshov, Sweden

Björn Eriksson