Caterpillar Inc.

Timothy A Lorentz

Mathew D Guldan

Hoon Ki Lee

Kevin A Vernagus

Bradley John Will

Matthew Michael Tinker

Chintan Govindbhai Kothari

Sridhar Deivasigamani

Brian Eugene Lister

John Parker Timmons

Kevin G Meyer

Larry Ellis Kendrick

James B Maddock

Mark Allen Batdorff

Craig W Riediger

David John Schuh

Jay Robert Steffen

Satish Yadav

Jeffrey T Ryan

James D Esterby

David J Andres

Robert Urban Murray

David Langsford Collins

Brian James Williams

Donald E Wilson

Brent G Drews

Gareth John Estebanez

In hydraulic systems having rotating-stationary component interfaces, a bore pressure regulating mechanism is provided to interact with the hydraulic fluid in a control volume to maintain a hydraulic fluid pressure in a longitudinal shaft bore at or approximately equal to a supply pressure when a gear shaft rotates within the control volume. In one aspect, the bore pressure regulating mechanism minimizes vortex flow of the hydraulic fluid induced by the rotation of the gear shaft. In another aspect, the bore pressure regulating mechanism provides a direct feed of pressurized hydraulic fluid proximate an opening of the longitudinal shaft bore through an end surface of the gear shaft, and thereby minimizes the opportunity for the hydraulic fluid to be forced into vortex flow by the gear shaft in the area of the longitudinal shaft bore.

Vortex diffuser for rotating/stationary interfaces

A transmission system is disclosed for use with a machine. The transmission system may have a first clutch configured to transfer power in a first direction, a second clutch configured to transfer power in a second direction, a brake, and an interface device configured to generate a first signal indicative of a desire to shift power transfer directions. The transmission system may also have a controller configured to cause disengagement of the first clutch in response to the first signal, to cause the brake to apply a retarding torque to a traction device, and to determine an amount of the retarding torque being applied to the traction device. The controller may also be configured to selectively transfer the retarding torque to the second clutch when a capacity of the second clutch to provide retarding torque is about equal to the amount of the retarding torque being applied by the brake.

Transmission system implementing automated directional shift braking

A transmission system is disclosed for use with a machine. The transmission system may have a first clutch to transfer power in a first direction, a second clutch to transfer power in a second direction, a brake, a sensor to generate a first signal indicative of speed, and an input device to generate a second signal indicative of a desire to shift directions. The transmission system may also have a controller to cause disengagement of the first directional clutch in response to the second signal, and to cause the brake to apply retarding torque. The controller may also be configured to determine an error value based on the second signal and a target transmission system speed, to selectively increase retarding torque when the error value increases, and to selectively transfer retarding torque to the second directional clutch when a value of the second signal is less than a threshold value.

A system for shifting a transmission includes an off-going clutch, an on-coming clutch, and an assisting clutch. A controller is configured to increase an amount of torque carried by each of the on-coming clutch and the assisting clutch. The controller is further configured to reduce an amount of torque carried by the off-going clutch and, after the off-going clutch is disengaged, to reduce the amount of torque carried by the assisting clutch.

System for controlling a transmission

A control system for a transmission engages at least three clutches to create braking within the transmission to slow a machine during a shuttle shifting operation. The control system may apply the clutches so as to allocate wear between the clutches equally or unequally, as desired.

System for allocating transmission clutch wear

A transmission assembly for a machine is disclosed. The transmission assembly may have a clutch pack, a first pressure chamber, and a second pressure chamber. The transmission assembly may also have a first piston configured to push against the clutch pack when pressurized fluid is directed into the first pressure chamber, and a second piston configured to push against the first piston when pressurized fluid is directed into the first pressure chamber and inhibited from pushing against the first piston when pressurized fluid is directed into the second pressure chamber.

Transmission assembly having variable force clutch

A control system for a transmission engages three clutches to create braking within the transmission to slow a machine during a shuttle shifting operation. The control system may apply the clutches so as to allocate wear between the clutches equally or unequally, as desired.

An exemplary power management system may include a power source and a transmission. The transmission may include a drive member and at least two shift ranges. The drive member may be driveably engaged with the power source. The power management system may also include a control system in communication with the power source and the transmission. The control system may be operative to cause a shift transition between the at least two shift ranges in response to a shift command. The control system may also be operative, during at least a portion of the shift transition, to modify at least one of a speed of the drive member and a speed of the power source based on at least one of a load condition of the power source, a speed of the power source, and the at least two shift ranges.

Power management system

A method and system may be provided to perform a process for controlling power provided by an engine in a machine. In an embodiment of the present invention, a process for controlling power provided by an engine operating in a machine is provided. The process may include determining a first power value reflecting a predetermined first power to be provided by the engine to a component operating in the machine and determining, during machine operations, at least one of a parasitic load power value and an intermittent power load value. A second power value may then be determined that reflects a second power provided by the engine based on the parasitic power value, the intermittent power value, and the net power value. The second power value is adjusted such that the engine substantially provides the predetermined net power to the component.

System for dynamically controlling power provided by an engine

A drive line assembly for a work machine is disclosed. The drive line assembly includes an engine driving an engine output shaft and an engine speed sensor which generates engine speed signals indicative of a speed of the engine output shaft. The drive line assembly further includes a fuel injector operable to regulate fuel flow to the engine and a transmission driven by the engine output shaft and having a number of gear ratios. The drive line assembly yet further includes a controller operable to store a predetermined maximum efficiency curve of engine speed versus torque output and determine the engine speed from the engine speed signals. The controller is further operable to limit the fuel flow the fuel injector supplies to the engine to cause the engine to operate along the predetermined maximum efficiency curve for the engine speed. The controller is yet further operable to control shift points between the number of gear ratios based on the predetermined maximum efficiency curve. A method for controlling a drive line assembly is also disclosed.

Method and apparatus for operating a transmission coupled to an engine for enhanced fuel efficiency characteristics

A method is provided for controlling a PTO clutch of a transmission subject to a varying inertial load. The method includes providing a signal to a pressure control valve selectively engaged with the PTO clutch configured to engage a drive source of the transmission with an implement. The signal to the pressure control valve is modulated based on a single predetermined profile.

Power take-off clutch control system

A method of determining shift points in a step gear transmission system to maximize fuel economy is disclosed. In operation, the method uses fuel economy data from a first gear ratio to determine a first series of constant fuel consumption curves for the first gear ratio. The method then uses fuel economy data from a second gear ratio to determine a second series of constant fuel consumption curves for the second gear ratio. Next, the method determines points of intersection where a respective fuel consumption curve for the first gear ratio intersects its corresponding fuel consumption curve for the second gear ratio. A decision curve is generated from the points of intersection.

Constant groundspeed autoshift method and apparatus for maximizing fuel economy

A drive line assembly for a work machine is disclosed. The drive line assembly includes an engine driving an engine output shaft and an engine speed sensor which generates engine speed signals indicative of a speed of the engine output shaft. The drive line assembly further includes a fuel injector operable to regulate fuel flow to the engine and a transmission driven by the engine output shaft and having a first on-coming clutch. The drive line assembly yet further includes a controller operable to determine the engine speed from the engine speed signals and determine the fuel flow through the fuel injector. The controller is further operable to determine an engine load based on the fuel flow and a predetermined maximum fuel flow for the engine at the engine speed and control engagement of the first on-coming clutch based on the engine load. A method for controlling a drive line assembly is also disclosed.

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Morton, IL, United States of America

Timothy A Lorentz