Husco International, Inc.

David Schedgick

Matthew James Rades

Eric Norman Griesbach

Jason Greenwood

Bradley James Kramer

Joe Pfaff

Michael J Karolek

Douglas Carl Blotz

A pump system has a piston pump. The piston pump has a cylinder block with an inlet port, an outlet port, and a plurality of cylinders. Each cylinder in the plurality of cylinders is connected to the inlet port by an inlet passage and to the outlet port by an outlet passage. The piston pump has a plurality of pistons disposed in the plurality of cylinders. A drive shaft drives the pistons within the cylinders. A throttle member independently throttles flow in each inlet passage. The pump system has an electrohydraulic actuator governing movement of the throttle member.

Hydraulic piston pump with throttle control

A hitch on a vehicle is raised and lowered by a hydraulic actuator controlled by an electrically operated valve. A control system receives a command that indicates a designated velocity and uses the command to operate the valve. Based on a reference external force exerted on the hitch, the control system is configured with relationships for converting a plurality of command values to corresponding electric current levels for operating the valve. The control system compensates for effects due to differences between the actual force acting on the hitch and the reference external force. Velocity feedback adjusts the electric current level applied to the valve. The passive load force control provides a predictor of the hitch load force to eliminate overshoot/undershoot of hitch motion. During hitch motion, the velocity feedback also compensates for effects due to load and hitch geometry changes that occur.

Passive load and active velocity based flow compensation for a hydraulic tractor hitch

A system for operating a single acting hydraulic cylinder includes a directional valve that has one extreme position in which a workport is connected to a tank return conduit, another extreme position where the workport is connected to a pump supply conduit, and a closed intermediate a position where the workport is disconnected from both the pump and the tank. The directional valve is pilot operated and is biased toward the one extreme position by a spring. An electrically operated primary applies pilot pressure to the directional valve alternately from the pump supply conduit and the tank return conduit. A pilot operated check valve has a first state which restricts fluid flow only from the workport toward the chamber and a second state in which fluid can flows from the chamber to the workport. The system has a pressure compensation that also provides self priming of the directional valve.

Valve control valve circuit for operating a single acting hydraulic cylinder

The hitch on a vehicle is moved by a hydraulic actuator. A method for controlling the hydraulic actuator defines a draft force setpoint in response to separately averaging two forces acting on lateral sides of the hitch, while operating in a configuration mode. During regular operation, a draft load is calculated from sensing those two forces and deriving a draft force error from difference between the draft load and the draft force setpoint. The draft force error is used to control fluid flow to and from the hydraulic actuator. One aspect of the control method derates the draft force error as the hitch moves beyond a predefined threshold position.

Draft control method for operating an earth moving machine

A hydraulic suspension system for a vehicle includes a pair of cylinders on opposite sides of the vehicle. Each cylinder is divided by a piston into two chambers. When the vehicle is not making a significant turn, a switching valve connects the chambers in the same cylinder together and when a significant turn occurs, the switching valve cross connects the chambers of the two cylinders. That cross connection increases resistance of the suspension system to roll of the vehicle, as compared to when the cylinder chambers are not cross connected. A load leveling function also is included in the hydraulic suspension system.

Vehicle suspension with selectable roll stabilization

A suspension system dampens motion between two components of a vehicle, such as the wheels and the chassis. An assembly of a cylinder and a piston is connected to both components. The piston defines first and second chambers in the cylinder and has a shaft with an end surface exposed to pressure within a third chamber of the cylinder. A first accumulator is connected to the first chamber by a first accumulator valve and a second accumulator valve connects a second accumulator to the second chamber. A damping valve alternately connects the third chamber to either the second chamber or a fluid tank wherein that connection defines the stiffness of the suspension system and is made in response to force acting on the suspension system. A load leveling circuit also is described.

Hydro-pneumatic vehicle suspension system with a double acting cylinder and accumulators

A vehicle has an axle connected to a frame by at least one hydraulic cylinder with two chambers separated by a piston. A hydraulic circuit controls flow of fluid between two cylinder chambers and between the chambers and an accumulator to dampen motion of the frame relative to the axle. The hydraulic circuit includes a control valve and a pair of check valves arranged so that the single control valve is able to lock-out the cylinder to emulate a rigid connection of the frame to the axle, as needed.

Hydraulic suspension with a lock-out mechanism for an off-highway vehicle

A hydraulic actuator for an active of semi-active vehicle suspension system has a cylinder with a piston therein. A piston rod is attached to the piston and extends out of the cylinder. First and second chambers are formed on opposites sides of the piston enabling the piston to be driven in a manner that counteracts vibrations in the vehicle, A third chamber is provided in the cylinder for connection to a load leveling apparatus. A novel structure reduces the overall length of the hydraulic actuator. A displacement sensor is incorporated into the hydraulic actuator to provide an electrical signal that indicated how far the piston rod extends from the cylinder.

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Menasha, WI, United States of America

David Schedgick