Caterpillar Inc.

Shin Caterpillar Mitsubishi Ltd.

Other

Caterpillar Japan Ltd.

Aleksandar M Egelja

Pengfei Ma

Jiao Zhang

Matthew James Beschorner

Mikhail A Sorokine

Michael Todd Verkuilen

Tetsuya Yoshino

Tonglin Shang

Hongliu Du

Dayao Chen

Kalpesh Patel

Sabri Cetinkunt

Kalpeshkumar N Patel

Benjamin Yoo

Santosh Ancha

Shoji Tozawa

Thomas P Muller

Justin Douglas Speichinger

Richard George Ingram

Rustu Cesur

Randy N Peterson

John Ferraz, Jr

Ryan Patrick McEnaney

Eric Hughes

Randal Peterson

Bryan A Johnson

Mark Vonderwell

Shogo Tada

David J Lomax

Unnat Pinsopon

Chenyao Chen

Hideki Nakajima

Barrett A Flinn

Aleem Junaidi

Yun Guo

Gene Richard St Germain

James D Linerode

Darren A Blum

Michael T VerKuilen

Trung Q Nguyen

Manu Murthy

Rangamani Srikrishnan

Mikhall A Sorokine

Michael A Sorokine

Robert Scot Lehmann

Todd Lawrence Baker

Jason J Podany

Takayuki Sasaki

Shuhei Orimoto

One embodiment of a hydraulic system for a machine has a first hydraulic circuit including a first pump coupled to a first hydraulic actuator configured to move a first implement of the machine. A second hydraulic circuit includes a second pump coupled to a second hydraulic actuator configured to move a second implement. An electric motor mechanically couples to the first pump and to the second pump. An operator interface receives input from an operator requesting movement of the first and second implements. A controller communicatively coupled to the electric motor and to the operator interface determines, based on the requested movement of the first and second implements respectively, first and second flow allocations respectively for the first and second pumps and determines respective target displacements for the first and second pumps. The controller also determines first and second target electric motor speeds based on the target displacements for the first and second pumps, respectively, and controls the electric motor to operate at the larger of the first and second target electric motor speeds.

Method and systems for controlling electrically-powered hydraulic circuits

A monitoring system includes a hydraulic accumulator including a piston movably disposed therein. At least one seal encompasses the piston. A first pressure sensor is configured to monitor pressure of a first fluid in a first chamber. A second pressure sensor is configured to monitor pressure of a second fluid in a second chamber. A first temperature sensor is disposed in the first chamber and configured to monitor the temperature of the first fluid. A second temperature sensor is disposed in the second chamber and configured to monitor the temperature of the second fluid. An electronic control unit is in communication with the sensors and programmed to in response to receiving pressure signals from the pressure sensors and temperature signals from the temperature sensors, determine a wear volume of the at least one seal; and compare the wear volume of the at least one seal to a predetermined threshold wear volume of the at least one seal to determine the remaining useful life of the hydraulic accumulator.

Hydraulic accumulator health monitoring and remaining life system

A hydraulic system is disclosed. The hydraulic system may include a source of pressurized fluid; a tank; a hydraulic actuator including a first chamber and a second chamber; a first independent metering valve disposed between and fluidly connected to the source, the tank, and the first chamber of the hydraulic actuator; and a second independent metering valve disposed between and fluidly connected to the source, the tank, and the second chamber of the hydraulic actuator. Each of the first independent metering valve and the second independent metering valve may include a spool and a valve actuator disposed on one side of the spool. The valve actuator may include a push coil, a pull coil, and a force feedback mechanism configured to balance a force of the push coil and the pull coil.

Split spool valve

A fluid system for a machine that includes a linkage. The fluid system includes an actuator, an accumulator, a pilot circuit, and a pressure reducing valve. The actuator is configured to manipulate the linkage. The accumulator is configured to store a fluid discharged by the actuator under pressure. The pilot circuit is fluidly coupled to the accumulator and is configured to receive the fluid from the accumulator. Further, the pressure reducing valve is positioned between the accumulator and the pilot circuit to regulate the pressure of the fluid delivered to the pilot circuit from the accumulator.

Fluid systems for machines with integrated energy recovery circuit

A system for determining an estimated output from a variable displacement hydraulic pump includes a prime mover, a torque sensor, a pressure sensor, and a displacement sensor. A controller is configured to determine the output torque from the prime mover, determine an input torque to the variable displacement hydraulic pump based upon the output torque, determine an output from one of the pressure sensor and the displacement sensor based upon the signals. The controller is further configured to determine a failure of another of the pressure sensor and the displacement sensor and determine an estimated output from the another of the pressure sensor and the displacement sensor based upon the input torque to the variable displacement hydraulic pump and the output from the one of the pressure sensor and the displacement sensor.

System for estimating a sensor output

A system for determining an estimated output from a variable displacement hydraulic pump includes a prime mover, and torque, pressure, and displacement sensors. A controller determines the output torque from the prime mover, determines an input torque to the variable displacement hydraulic pump based upon the output torque, determines an output from one of the pressure sensor and the displacement sensor, and determines an inertia torque loss based upon the angular acceleration of the prime mover. The controller further determines a failure of another of the pressure sensor and the displacement sensor and determines an estimated output from the another of the pressure sensor and the displacement sensor based upon the input torque to the variable displacement hydraulic pump, the output from the one of the pressure sensor and the displacement sensor, and the inertia torque loss.

A system can include one or more valve arrangements with a working chamber to receive a working fluid at a first pressure, and a control chamber to receive fluid at a second pressure. A dynamic seal can be disposed on a land of a valve element. A supply passage can be in communication between the control chamber and a tank and can include a check valve. A relief valve can be disposed between the check valve and the control chamber. A pilot pump and another relief valve may be disposed upstream of the check valve. The relief valve downstream of the check valve can have a higher pressure limit than the downstream one. A pressure sensor may be disposed between the check valve and the control chamber and used to warn the operator of a high pressure in the control chamber.

Dynamic seal wear mitigation system

A hydraulic control system for a machine is disclosed. The hydraulic control system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, an actuator, and a control valve configured to direct fluid from the pump to the actuator and from the actuator to the tank to move the actuator. The hydraulic system may also have a main relief valve movable away from a closed position to pass pressurized fluid to the tank when a pressure of the fluid directed to the actuator exceeds a first threshold pressure, and a controller in communication with the pump. The controller may be configured to selectively reduce a displacement of the pump after the main relief valve has moved away from the closed position when the pressure of the fluid directed to the actuator exceeds a second threshold pressure.

Hydraulic control system having over-pressure protection

An independent metering valve (IMV) assembly is disclosed that includes a metering stem including an inlet. The IMV assembly also includes a hydro-mechanical control valve in communication with a fluid source and the inlet. The control valve also including a spool with a closed end and an open end. The control valve includes a biasing member that biases the control valve or spool towards an open position thereby establishing communication between the fluid source and the inlet. The control valve also including a load signal line providing communication between an outlet of the control valve upstream of the inlet and the closed end of the spool. Wherein high pressure in the load signal line allowing the control valve to move towards a closed position thereby overcoming bias of the biasing member and reducing flow to the inlet during a high pressure condition.

Independent metering valve with flow limiter

A hydraulic system for an earth-moving vehicle may include first and second hydraulic cylinders, first and second hydraulic pumps and control valves including a combiner valve to modulate hydraulic fluid and pressure from the first and second hydraulic pumps to the first and second hydraulic cylinders as appropriate for the task being performed. If the task is digging, the first and second cylinders may be associated with tilting and lifting, respectively, and the control valves may be oriented so as to make each pump dedicated to one of the cylinders, and if demand is not being met, to then diminish power to the drivetrain to allow the tilting and lifting to be performed. The combiner valve may or may not be open during this time. If the task is not digging, the combiner valve can be opened to allow for cross-flow between the pumps and the cylinders.

Multi-function wheel loader linkage control with optimized power management

A control system for a machine is disclosed. The control system may have a pump, a low pressure reservoir, and at least one actuator connected to receive fluid pressurized by the pump and discharge fluid to the low pressure reservoir. The control system may also have a bypass passage situated to allow fluid to bypass the at least one actuator, and a warmup valve disposed within the bypass passage and being movable between a flow-passing position and a flow-blocking position. The control system may further have a hydraulic temperature sensor configured to generate a signal indicative of a temperature of the fluid, and a controller in communication with the pump, the warmup valve, and the hydraulic temperature sensor. The controller may be configured to move the warmup valve to the flow-passing position, fix a displacement position of the pump, and adjust an input speed of the pump in response to the signal.

Machine control system having hydraulic warmup procedure

A method of calibrating an electrically controlled hydraulic valve having a known relationship between flow rate through the valve and displacement of a valve element is disclosed. The method includes ascertaining a first current level for actuating the electrically controlled hydraulic valve to move the valve element to a position adjacent an inlet port, and a first displacement of the valve element responsive to the first current level. The method also includes ascertaining a second current level for actuating the electrically controlled hydraulic valve to move the valve element from the position adjacent the inlet port to a position permitting flow through the inlet port, and ascertaining a second displacement of the valve element responsive to the second current level. The method further includes establishing a relationship between current and displacement associated with the electrically controlled hydraulic valve.

Electrically controlled hydraulic valve calibration method and system

A method of controlling an electro-hydraulic system having an engine driving a variable displacement pump, a hydraulic valve and a hydraulic actuator in order to achieve more efficient engine operation is disclosed. The pressures in the electro-hydraulic system are monitored and commands are received indicating the desired movement of the hydraulic actuator. Based on the pressure and the commands, the operation being performed by the machine is determined and the engine is set to an efficient setting for the particular segment of machine operation.

Process for electro-hydraulic circuits and systems involving excavator boom-swing power management

The present disclosure is directed to a hydraulic system. The system includes a first source of pressurized fluid and at least one fluid actuator. The system also includes a first valve disposed between the first source and the at least one fluid actuator being configured to selectively communicate pressurized fluid from the first source to a source of low pressure. The system further includes a controller configured to determine a first amount of displacement of the first valve, determine a second amount of displacement of the first valve, and modify the first amount of displacement as a function of the second amount of displacement when a first pressure is less than or equal to a pressure of pressurized fluid acting on the at least one fluid actuator.

Hydraulic system having pressure compensated bypass

A hydraulic control system for a work machine is disclosed. The hydraulic control system has a fluid actuator, a supply of pressurized fluid, and a control valve movable to selectively pass pressurized fluid to the fluid actuator. The hydraulic control system also has a sensor configured to sense the pressure of the pressurized fluid passed to the fluid actuator and a controller in communication with the control valve and the sensor. The controller is configured to receive an input indicative of a desired velocity of the fluid actuator and to determine a fluid flow rate corresponding to the desired velocity. The controller is also configured to determine a ratio of the sensed pressure to a stall pressure of the supply and to scale down the determined flow rate an amount based on the determined ratio. The controller is further configured to move the control valve an amount corresponding to the scaled down flow rate.

Multi-actuator pressure-based flow control system

Growing community of inventors

Naperville, IL, United States of America

Aleksandar M Egelja