Caterpillar Inc.

Beau Kuipers

Edward William Mate

David Mork

Andrew Nathan Schifferer

Daryl Belshan

Fuaad Sayeed

Patrick W Sullivan

Royce E Leaders

Ryan Robert Stoffel

Nathanael Garnet McRostie

Patrick William Sullivan, Jr

Glenn Stanfield

Gene Richard St Germain

A hydraulic system for a machine includes an implement pump, a valve, and an implement valve subsystem. The implement pump includes a load sensing control, and the valve controls the flow of hydraulic fluid to the implement pump. The implement valve subsystem includes one or more implement control subsystems to control movement of an implement. The valve is an electrohydraulic proportional relief valve and includes a solenoid configured to adjust the pressure of hydraulic fluid delivered to the implement pump proportionally to a current delivered through the solenoid.

Hydraulic system and methods for an earthmoving machine

A steering system for a machine is disclosed. The steering system may include a first pilot system including a first pilot source and a first set of electrohydraulic valves, and a second pilot system including a second pilot source and a second set of electrohydraulic valves. The first pilot system and the second pilot system may be configured to move the steering valve via pilot flow of the hydraulic fluid. The steering system may further include an electrohydraulic selector valve configured to regulate pilot flow to the first set of electrohydraulic valves and the second set of electrohydraulic valves. The electrohydraulic selector valve may be a two-position, five-way valve.

Electrohydraulic steering system with diagnostics

A steering control system includes a steering circuit, a primary control circuit and a redundant control circuit. The primary control circuit includes primary proportional control valves, and a primary pilot valve having a thermal bleed of pilot fluid to warm the primary pilot valve when not operating to control the steering circuit. The redundant control circuit includes secondary proportional control valves, and a pressure reducing valve having a thermal bleed orifice allowing fluid flow to warm the pressure reducing valve when not operating to control the steering circuit. The thermal bleeds may also flow past the proportional control valves to raise their temperatures. The circuits of the steering control system are contained in a single valve group housing.

Electro-hydraulic steering control system

A steering system and method for providing a force feedback to an operator input device are disclosed. The method may determine an actual position of the operator input device. The method may determine a desired steering mechanism position of a steering mechanism based on the actual position of the operator input device. The method may determine an actual steering mechanism position of the steering mechanism. The method may compare the actual steering mechanism position to the desired steering mechanism position and to a previous desired steering mechanism position. The method may generate a command that selectively activates force feedback to the operator input device based on the comparison.

System with smart steering force feedback

A machine includes a hydraulic fan system for circulating cooling air through an engine compartment. Periodically, the fan rotation direction is briefly reversed in order to dislodge any material debris that may have accumulated at the inlet to the engine compartment. When a fan reversal event is initiated, the fan motor will continue to rotate due to angular momentum even after the pump output flow has been switched from a first motor port to a second motor port. During this continued rotation as the fan decelerates to zero speed, vacuum pressure levels can arise at the first motor port, and a pressure spike can develop at the second motor port. In order to alleviate these conditions, a pressure transfer valve briefly opens to facilitate fluid flow directly from the second motor port to the first motor port as the fan motor decelerates towards zero speed before reversing direction, simultaneously alleviating vacuum and pressure spike conditions.

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Morris, IL, United States of America

Beau Kuipers