Abstract: Operating an electric drive machine includes neutralizing a transmission in the electric drive machine operating in a first range, determining suitability of the electric drive machine for operating the transmission in a second range, and calculating a target transmission input speed, based on a speed parameter indicative of a transmission output speed, and the determined suitability for operating in a second range. A speed of an electric drive motor is varied based on the target transmission input speed, and a second clutch engaged to operate the transmission in the second range based on the varied speed of the electric drive motor. Related apparatus and control logic is also disclosed.

Abstract: An electric powertrain includes a transmission connected with a traction motor to receive motive power embodied as torque and speed. To adjust the torque and speed, the transmission has a plurality of gear sets that are selectively engaged by actuation of associated hydraulic clutches. For actuation, the hydraulic clutches receive hydraulic fluid from a hydraulic system. To calibrate actuation of the clutches, the traction motor is run at a reduced speed range under calibration conditions while the hydraulic system is operated at a operational speed range. Further, a torque/current limit is applied to the traction motor to limit torque applied to the transmission during calibration.

Abstract: 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.

Abstract: An electric powertrain includes a transmission connected with a traction motor to receive motive power embodied as torque and speed. To adjust the torque and speed, the transmission has a plurality of gear sets that are selectively engaged by actuation of associated hydraulic clutches. For actuation, the hydraulic clutches receive hydraulic fluid from a hydraulic system. To calibrate actuation of the clutches, the traction motor is run at a reduced speed range under calibration conditions while the hydraulic system is operated at a operational speed range. Further, a torque/current limit is applied to the traction motor to limit torque applied to the transmission during calibration.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Operating an electric drive machine includes neutralizing a transmission in the electric drive machine operating in a first range, determining suitability of the electric drive machine for operating the transmission in a second range, and calculating a target transmission input speed, based on a speed parameter indicative of a transmission output speed, and the determined suitability for operating in a second range. A speed of an electric drive motor is varied based on the target transmission input speed, and a second clutch engaged to operate the transmission in the second range based on the varied speed of the electric drive motor. Related apparatus and control logic is also disclosed.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.