Caterpillar Inc.

Brian Eugene Lister

Michael David Beyer

Gaurav Vasudeva

Chad Timothy Brickner

Michael John Barngrover

Konrad Garrett

Aaron Benjamin Crabtree

Christopher Rhoades

Sridhar Deivasigamani

Jason J Stoller

Brian Dean Kuras

Todd R Kabrich

Adam Martin Nackers

Adam Vaccari

Larry Ellis Kendrick

Timothy A Lorentz

James B Maddock

Richard B League

Glen Patrick Calvert

Vaibhav H Shah

Tyler Bowman

Kevin A Vernagus

Satish Yadav

David Langsford Collins

Robert Urban Murray

Alex M Fullenkamp

Tom Brosowke

Andrew W Sloan

Gareth John Estebanez

Mike Barngrover

Ryan R Leman

Bernard M Murphy

A transmission associated with a powertrain receives torque from a power source and includes a plurality of gear sets that can be selectively engaged and released. To shift gear sets, a shifting process conducted by an electronic controller may estimate a torque assist capacity of the power source to provide or accommodate changes in torque during the gear shift. If the torque assist capacity is less than a gear shift torque value, the shifting process prevents or ignores the gear shift.

Gear shifting process for powertrain transmission

A mobile machine can include a traction powertrain configured to operate on electrical power and which includes a traction motor coupled to a transmission. To lubricate the transmission, the mobile machine can include a lubrication system having a lubricant pump coupled with a pump motor. The traction motor and the pump motor are electrically arranged in parallel with each other. A powertrain sensor monitors rotational motion in the traction powertrain and an electronic controller can generate a lubricant supply command directing the lubricant pump to deliver a first lubricant quantity to the transmission.

Lubrication system for a traction powertrain

A system and method for controlling a motor of an electric drivetrain having a multi-speed transmission with at least a first clutch and a second clutch. The system and method includes initiating a transmission shift requiring engagement of the first clutch, applying synchronizing torque commands to the motor based on an engagement parameter of the first clutch until the shift is complete, and applying non-shifting torque commands to the motor after the shift is complete.

System and method for controlling a motor during clutch shifting in a multi-speed electric drivetrain

An electric powertrain includes an electric power source, an electric motor and a multi-speed transmission. The powertrain has an electronic controller. The controller determines a respective rimpull torque limit for the operating gear of the multi-speed transmission and determines whether the rimpull torque demand exceeds the rimpull torque limit. Upon determining that the rimpull torque demand exceeds the rimpull torque limit, the controller acts to either (i) shift the multi-speed transmission to a gear in which the respective rimpull torque limit is at or above the rimpull torque demand or (ii) reduce the electric motor torque command to a level for which the rimpull torque is below the respective rimpull torque limit for the operating gear of the multi-speed transmission.

Electric powertrain with rimpull torque limit protection

A machine can include an electric powertrain configured for electrical power and which includes a transmission. The transmission may be operatively associated with a hydraulic system that includes a hydraulic pump and a pressure relief valve disposed between the pump and the transmission. To reduce noise generated by the pressure relief valve, operation of the pressure relief valve may be regulated according to a pump function that relates operation of the pressure relief valve with a sensed pump operation associated with the hydraulic pump.

Electric powertrain and method of operation

An electric drive system for a machine includes a transmission, and an electric drive motor coupled to a transmission input. The electric drive system also includes a plurality of sensing subsystems, each monitoring a speed of rotation and a direction of rotation of one of the electric drive motor or the transmission input. An electric drive control system in the electric drive system includes an electronic controller structured to receive health data of the sensing subsystems, and determine a drive system control command, according to a sensor data sourcing pattern that is dependent upon the health data. Related methodology and control logic is also disclosed.

Electric drive system for machine configured for switching sensor data sourcing pattern based on health status

A variable drive system, to drive an accessory drive of a machine may include a first variable pulley to be mechanically coupled to the accessory drive and an engine output of an engine. The variable drive system may also include a second variable pulley to be mechanically coupled to a flywheel. The variable drive system may include a drive element to rotate, according to a clutch system, about the first variable pulley and the second variable pulley to at least one of: drive the second variable pulley to charge the flywheel with kinetic energy or drive the first variable pulley via kinetic energy from the flywheel.

Variable speed drive for an accessory drive in a hybrid power system

A transmission for a machine is disclosed. The transmission may comprise a first torque path for transmission of torque from an input shaft to an output shaft, and a single clutch element along the first torque path. The transmission may further comprise a clutch actuator configured to actuate engagement of the clutch element, and a clutch pressure control (CPC) valve configured to permit a flow of hydraulic fluid to the clutch actuator when in an open position to cause the clutch actuator to actuate engagement of the clutch element. The transmission may further comprise a FMR valve having a failure position obstructing flow of the hydraulic fluid from the CPC valve to the clutch actuator when the CPC valve is in the open position. The FMR valve actuated by pilot pressure from a CPC valve that controls actuation of other clutch elements that are not on the first torque path.

Clutch hydraulic control circuit with a pilot operated failure mode response valve

A transmission for a machine is disclosed. The transmission may comprise a torque path providing a path for transmission of torque from an input shaft to an output shaft, and a single clutch element along the torque path. The transmission may further comprise a clutch actuator configured to actuate engagement of the clutch element, and a clutch pressure control (CPC) valve configured to permit a flow of hydraulic fluid to the clutch actuator through a control pressure line when in an open position to cause the clutch actuator to actuate engagement of the clutch element. The transmission may further comprise a failure mode response (FMR) valve in the control pressure line between the CPC valve and the clutch actuator. The FMR valve may have a failure position obstructing flow of the hydraulic fluid from the CPC valve to the clutch actuator when the CPC valve is in the open position.

Machine transmission with clutch element hydraulic control

A launch control method for a continuously variable transmission (CVT) is provided, where the CVT comprises a hydro-mechanical variator, a summing transmission connected to an output side of the variator, and a clutch for selectively connecting the summing transmission to an output member. The method determines whether a launch has been requested, and adjusts a variable displacement pump of the variator to a predetermined fixed displacement. Engagement of the clutch is commenced, and the method then determines whether a predetermined degree of slip exists between input and output elements of the clutch. The clutch is held at its present state of engagement when the predetermined degree of slip has been established, and the variator is placed into a torque control mode. The method then determines when there is zero slip between the input and output elements of the clutch, and then instructs full engagement of the clutch. The method then holds the pump of the variator at its current displacement until a predetermined time period has elapsed, before reverting to a standard transmission control algorithm. A CVT is also provided.

Variator-assisted transmission and launch control methods for such a transmission

A hydraulic circuit includes a clutch actuator operatively associated with a clutch that may be disposed in a transmission. A hydraulic fluid source supplies pressurized hydraulic fluid for the clutch actuator. To measure the filling rate of the hydraulic actuator, a reference actuator having a predetermined filling rate is disposed in parallel with the hydraulic actuator and in fluid communication with the hydraulic fluid source. If hydraulic pressure associated with the reference actuator does not correspond to the hydraulic pressure associated with the clutch actuator, a compensation valve can appropriately respond by selectively directing hydraulic fluid to or from the clutch actuator. In a further embodiment, the reference actuator and compensation valve may be replaced with an electrohydraulic valve utilizing feedback from the hydraulic pressure present at the inlet of the clutch actuator.

Hydraulic circuit for clutch actuation

A machine may include an engine, a traction device, a continuously variable transmission (CVT) connecting the engine to the traction device, an operator input device outputting engine output command signals input by an operator, an engine speed sensor monitoring an engine output speed, and an electronic control module (ECM). The ECM controls a machine output of the machine by executing a transmission output control routine using transmission output parameters as feedback when transmission output parameter sensor signals are reliable. The ECM controls the machine output by executing a target engine speed control routine using an engine output speed sensor signals as feedback when the transmission output parameter sensor signals are nor reliable. In the target engine speed control routine, the ECM determines a CVT transmission ratio that will cause the CVT to apply a load to the engine that will cause the engine to run at the target engine speed.

CVT target engine speed control with unreliable output feedback

A machine may include an engine, a traction device, a continuously variable transmission (CVT) connecting the engine to the traction device, an operator input device outputting engine output command signals input by an operator, an engine speed sensor monitoring an engine output speed, and an electronic control module (ECM). The ECM may control the engine to a target engine speed using engine speed sensor signals as feedback. A desired percentage of peak power of the engine may be determined from the engine output command signals, and the target engine speed may be determined from the desired percentage of the peak power. The ECM determines a CVT transmission ratio that will cause the CVT to apply a load to the engine that will cause the engine to run at the target engine speed.

CVT target engine speed control with proportional power output governor

A machine may include an engine, a traction device, a continuously variable transmission (CVT) connecting the engine to the traction device, an operator input device outputting engine output command signals input by an operator, an engine speed sensor monitoring an engine output speed, and an electronic control module (ECM). The ECM may control the engine to a non-retarding target engine speed when a commanded engine output is greater than zero, a retarding target engine speed when the commanded engine output is zero and a commanded brake force is greater than zero, and a coasting target engine speed when the commanded engine output is zero and the commanded brake force is zero. The ECM may use engine speed sensor signals as feedback, and determine a CVT transmission ratio that will cause the CVT to apply a load to the engine that will cause the engine to run at the specified target engine speed.

CVT target engine speed control for coasting and retarding

A machine may include an engine, a traction device, a continuously variable transmission (CVT) connecting the engine to the traction device, an operator input device outputting engine output command signals input by an operator, an engine speed sensor monitoring an engine output speed, and an electronic control module (ECM). The ECM may control the engine to a target engine speed determined from the engine output command signals using engine speed sensor signals as feedback. The ECM determines a CVT transmission ratio that will cause the CVT to apply a load to the engine that will cause the engine to run at the target engine speed.

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Edwards, IL, United States of America

Brian Eugene Lister