Caterpillar Inc.

Jason Brinkman

Randall Todd Anderson

Jeffrey Lee Kuehn

Rustu Cesur

Grant Steven Peterson

John James Krone

Pengfei Ma

Jiao Zhang

Jeffrey Kent Berry

Hongliu Du

Chad Timothy Brickner

Richard A Carpenter

Shaun D Currier

Peter Spring

Lawrence J Tognetti

Timothy L Hand

Jerry A Wear

Wesley Thomas Payne

Matthew Stephen Marquette

Bryan A Johnson

Mark Vonderwell

Mikhail A Sorokin

Randall A Harlow

Paul Douglas Hagen

Andrew Kleitsch

Robert A Aarestad

Eric P Jakubiak

Aristoteles Rosa Neto

Kevin Bacon

Jeff L Kuehn

Chris R Cesur

George M Romack

Pinaki Gupta

Greg A Ferkol

A system for determining a health status of a tank is provided. The system includes a temperature sensor, a pressure sensor, a sensor coupled to a hydraulic actuator, a breather valve, and a controller. The controller is configured to receive a signal indicative of a temperature and a volume of a fluid within the tank from the temperature sensor and the sensor coupled to the hydraulic actuator respectively. The controller is configured to determine an estimated pressure of the fluid within the tank based on the received signals and a breather performance curve. The controller is configured to receive a signal indicative of a pressure of the fluid within the tank and compare it with the estimated pressure. The controller is also configured to determine the health status of the tank and to actuate one or more of an operator console display unit and the hydraulic actuator.

System and method for determining a health status of a tank

A valve assembly is disclosed. The valve assembly includes a valve housing defining a bore, a first valve, and a second valve. The first valve and the second valve are disposed within the bore and each of the first valve and the second valve include a first end and a second end. Further, the first end of the first valve and the first end of the second valve are configured to contact each other. The valve assembly further includes a pilot chamber defined within the bore. The pilot chamber is configured to receive a pilot fluid. Further, a pressure of the pilot fluid inside the pilot chamber is controlled to permit independent movement of the first valve and the second valve within the bore.

Valve assembly

An independent metering valve circuit includes an actuator, a set of independent metering valves, an independent metering valve pre-compensator, an inverse resolver, and a signal conditioning element. The set of independent metering valves are fluidly coupled to the actuator and configured to independently control a flow of a hydraulic fluid to the actuator. The independent metering valve pre-compensator is configured to control the flow of the hydraulic fluid to the set of independent metering valves. The inverse resolver is configured to receive a first pressure signal from the independent metering valve circuit and a second pressure signal from a load-sense hydraulic system and output a third pressure signal. The signal conditioning element is configured to receive the third pressure signal and output a forth pressure signal configured to control a pump fluidly coupled to the load-sense hydraulic system and the independent metering valve circuit.

Hydraulic system including independent metering valve with flowsharing

An overspeed protection method for a machine having an engine drivably coupled to a pump is disclosed. The method includes determining a speed of a rotatable component connected to the engine based on an engine speed and determining a minimum power limit based on the speed of the rotatable component. The minimum power limit corresponds to a minimum power required to retard the engine in order to prevent an overspeed condition of the rotatable component. The method further includes determining a minimum flow limit based on a predetermined relationship between the minimum power limit and the minimum flow limit. The minimum flow limit corresponds to a required flow of the pump in order to provide the minimum power limit. The method further includes regulating the pump in order to achieve the minimum flow limit.

Rotatable component overspeed protection method

This disclosure provides for pressure limiting a hydraulic system to a desired pressure value by a particular circuit by controlling and closing the compensator when the desired pressure setting is achieved. Closing the compensator will reduced the pressure head and flow in the circuit resulting in improved efficiency. One illustrated embodiment of the disclosure provides a relief valve in the pilot signal for a compensator. The method relates to limiting the pressure on an open side of the compensator, such that the pressure on the other side closes the compensator thereby limiting the pressure and also flow in the hydraulic circuit. In other words, the pressure on the open side is limited by the relief valve. Thus, the pressure on the other side increases thereby regulating the flow and pressure through the compensator. In another embodiment of the disclosure, instead of reducing the pressure on the open side, the pressure on the closed side is increased, thereby controlling the flow and pressure of the hydraulic circuit. The pressure can be increased by a pump or any other suitable mode.

Pressure limiting in hydraulic systems

A machine includes a hydraulic cylinder configured to raise and lower a boom of the machine, and an accumulator selectively fluidly connected to the hydraulic cylinder. The accumulator is configured to receive fluid from the hydraulic cylinder during lowering of the boom. The machine also includes a hydraulic motor fluidly connected to the accumulator via an independent metering valve. The machine further includes a fan driven by the hydraulic motor and configured to assist in cooling fluid displaced from the hydraulic cylinder.

Hydraulic energy recovery system

A hydraulic system for a machine is disclosed. The hydraulic system may include a fluid tank, a first manifold, a valve body, a second manifold, and a plurality of conduits. The first manifold may be operatively attached to the fluid tank and have at least two inlets and at least one outlet in fluid communication with the fluid tank. The number of the at least one outlet may be less than the number of the at least two inlets. The second manifold may be operatively attached to the valve body and have at least one inlet in fluid communication with the valve body and at least two outlets. The number of the at least one inlet may be less than the number of the at least two outlets. The plurality of conduits may fluidly connect the at least two inlets of the first manifold and the at least two outlets of the second manifold.

Hydraulic system having dual manifolds

A hydraulic control system for a machine is disclosed. The hydraulic control system may have a hydraulic circuit, and a pump configured to supply pressurized fluid to the hydraulic circuit. The hydraulic control system may also have a first fluid actuator fluidly connected to receive pressurized fluid from the hydraulic circuit, a first valve arrangement movable to control a flow of fluid to the first fluid actuator, a second fluid actuator fluidly connected to receive pressurized fluid from the hydraulic circuit, and a second valve arrangement movable to control a flow of fluid to the second fluid actuator. The hydraulic control system may additionally have a controller in communication with the first and second valve arrangements. the controller may be configured to make a determination of a stall condition of the first fluid actuator, and to selectively change a flow command directed to the second valve arrangement based on the determination.

Hydraulic control system having cylinder stall strategy

A hydraulic system for a machine is disclosed. The hydraulic system may have a first pump with variable displacement and being load-sense controlled, and a first hydraulic circuit associated with the first pump. The hydraulic system may also have a second pump with variable displacement and being electro-hydraulically controlled, and a second hydraulic circuit associated with the second pump. The hydraulic system may further have a flow-sharing valve arrangement configured to selectively share fluid flow between the first and second hydraulic circuits.

Hydraulic system having implement and steering flow sharing

A hydraulic control system for a machine is disclosed. The hydraulic control system may have a hydraulic circuit, a pump configured to supply pressurized fluid, and a first sensor configured to generate a first signal indicative of a pressure of the hydraulic circuit. The hydraulic circuit may also have a first fluid actuator fluidly connected to receive pressurized fluid from the hydraulic circuit, a second sensor configured to generate a second signal indicative of a velocity of the first fluid actuator, and a controller in communication with the first and second sensors. The controller may be configured to receive an input indicative of a desired flow rate for the first fluid actuator, to determine an actual flow rate of the first fluid actuator based on the second signal, and to determine a stall condition of the first fluid actuator based on the desired flow rate, the actual flow rate, and the first signal.

A control for a variable displacement pump disposed in a hydraulic system obtains a requested signal from a manual control device and provides a command signal to a valve operating to adjust a displacement setting of the variable displacement pump. The control provides the command signal based on the requested signal, and scales the requested signal based on a sensed or calculated load of the system.

System and method for operating a variable displacement hydraulic pump

A fluid system for use with a machine that employs an actuator, that provides for rapid shaking of an implement. The fluid system includes a source for providing fluid flow to the actuator and an operator input device for enabling an operator to control the movement of the implement by inputting a plurality of commands that specify movement of the implement. A controller is provided for monitoring the commands received from the operator input device and entering a mode for controlling the displacement of the source when the controller detects a pattern of commands that indicates an operator-request for rapid movement of the implement.

System and method for rapidly shaking an implement of a machine

A hydraulic circuit is disclosed. The hydraulic circuit may have a variable displacement pump. The variable displacement pump may have a fluidic displacement control configured to vary a flow of pressurized fluid based on a fluid signal and an electronic displacement control configured to vary the flow of pressurized fluid based on an electronic signal. The flow of pressurized fluid may be controlled by the one of the fluidic and electronic displacement controls that requests the smallest flow of pressurized fluid. The hydraulic circuit may also have a control valve connected between the pump and the fluidic displacement control, and the control valve may be configured to transmit the fluid signal to the fluidic displacement control. The hydraulic circuit may further have a controller configured to transmit a fluid signal to cause the fluidic control to request a maximum flow of pressurized fluid, and transmit an electronic signal requesting a flow smaller than the maximum flow, which causes the electronic displacement control to vary the flow of pressurized fluid.

Hydraulic circuit for rapid bucket shake out

An energy recovery system for a machine is disclosed. The energy recovery system may have a pump configured to provide a flow of pressurized fluid. The energy recovery system may also have a first fluid actuator with a first chamber and a second chamber and being configured to receive the pressurized fluid, a second fluid actuator with a third chamber and a fourth chamber and being configured to receive the pressurized fluid, and a first valve fluidly connected between the pump and the first and second actuators. The energy recovery system may additionally include an isolation unit with a first selectively restrictable passageway fluidly connecting the first chamber, the third chamber, and a first outlet of the first valve, and a second selectively restrictable passageway fluidly connecting the second chamber, the fourth chamber, and a second outlet of the first valve, as well as an energy recovery unit in fluid communication with the isolation unit. The isolation unit may be configured to direct a flow of pressurized fluid from the second actuator to the energy recovery unit. The energy recovery unit may be configured to convert the flow of pressurized fluid to a first mechanical power output.

Energy recovery system

A cylinder assembly is disclosed. The cylinder assembly may include a cylinder body having an internal cavity therein and a piston and rod assembly disposed for axial movement within the internal cavity of the cylinder body. The piston and rod assembly may have an axial passage extending therein. The cylinder assembly may further include a tubular element received within the axial passage of the piston and rod assembly. At least a portion of the tubular element may extend out of the axial passage and into the internal cavity of the cylinder body between the axial passage and a wall of the cylinder body.

Growing community of inventors

Peoria, IL, United States of America

Jason Brinkman