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 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: 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 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: 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 with a clutch that may be disposed in a transmission. A hydraulic fluid source supplies pressurized hydraulic fluid for the clutch actuator. An on-off valve is disposed in fluid communication between the clutch actuator and the hydraulic fluid source; the on-off valve configured to fill the clutch actuator with hydraulic fluid. An accumulator is disposed in parallel with the on-off valve and in fluid communication with the clutch actuator. The accumulator is adapted to receive hydraulic fluid redirected from the clutch actuator and to provide a counter-pressure for modulating 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.

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 clutch assembly is provided. The clutch assembly includes a basket member, an input member and an actuator that is disposed within the basket member. A hub member, having a hub spline and an inclined portion is disposed adjacent to the actuator. A cam member, having a cam spline and cam lobes is rotatably disposed on the input member. A shaft member, having a shaft spline and plurality of slots is rotatably disposed on the input member. The hub spline is engaged with the cam spline in a disengaged position of the actuator. The clutch assembly further includes a plurality of balls received within the corresponding slots of the shaft member. While moving towards an engaged position of the actuator, the cam spline aligns with the shaft spline thereby the hub spline engages with the shaft spline in the engaged position of the actuator.

Abstract: A clutch plate for a clutch assembly is provided. The clutch plate includes a body defining an outer circumference. A plurality of extensions projects radially from the outer circumference of the body. A first separating member is formed by bending a portion of at least one of the plurality of extensions along a first direction. The first separating member is configured to resiliently separate the clutch plate from an adjoining clutch plate of the clutch assembly along the first direction in a disengaged condition of the clutch assembly. A second separating member is formed by bending a portion of at least another of the plurality of extensions along a second direction. The second separating member is configured to resiliently separate the clutch plate from another adjoining clutch plate of the clutch assembly along the second direction in the disengaged condition of the clutch assembly.

Abstract: A clutch assembly is provided. The clutch assembly includes a basket member, an input member and an actuator that is disposed within the basket member. A hub member, having a hub spline and an inclined portion is disposed adjacent to the actuator. A cam member, having a cam spline and cam lobes is rotatably disposed on the input member. A shaft member, having a shaft spline and plurality of slots is rotatably disposed on the input member. The hub spline is engaged with the cam spline in a disengaged position of the actuator. The clutch assembly further includes a plurality of balls received within the corresponding slots of the shaft member. While moving towards an engaged position of the actuator, the cam spline aligns with the shaft spline thereby the hub spline engages with the shaft spline in the engaged position of the actuator.

Abstract: In an embodiment, torque control operation is provided in a transmission having a variable displacement variator with a hydraulic actuator. The transmission is engaged in a neutral state such that the variator output experiences substantially zero torque, and a first hydraulic pressure sweep to the hydraulic actuator is commanded while a corresponding sweep of motor speed ratio of the variator is recorded. The transmission is engaged into a locked mode providing a fixed output speed and a second hydraulic pressure sweep to the hydraulic actuator is commanded, and a corresponding sweep of variator output torque is recorded during this sweep. A torque/pressure map is then constructed relating motor torque, motor speed ratio, and actuator pressure by scaling the sweep of motor speed ratios and the sweep of variator output torque. The resultant map is usable to provide feed forward torque control of the transmission.

Abstract: A machine is described that includes an engine, a multi-clutch transmission and a controller. The controller is configured with computer-executable instructions for managing operation of the multi-clutch transmission to avoid autoengagement of a disengaged clutch. The computer-executable instructions configure the controller to receive sensor signals indicative of current operating status of the machine; determine, based upon the sensor signals, a configured minimum engine speed needed to avoid autoengagement of the disengaged clutch; and conditionally increase an engine speed based upon a comparison of the configured minimum engine speed and a sensed current engine speed.

Abstract: A machine is described that includes an engine, a multi-clutch transmission and a controller. The controller is configured with computer-executable instructions for managing operation of the multi-clutch transmission to avoid autoengagement of a disengaged clutch. The computer-executable instructions configure the controller to receive sensor signals indicative of current operating status of the machine; determine, based upon the sensor signals, a configured minimum engine speed needed to avoid autoengagement of the disengaged clutch; and conditionally increase an engine speed based upon a comparison of the configured minimum engine speed and a sensed current engine speed.

Abstract: In an embodiment, torque control operation is provided in a transmission having a variable displacement variator with a hydraulic actuator. The transmission is engaged in a neutral state such that the variator output experiences substantially zero torque, and a first hydraulic pressure sweep to the hydraulic actuator is commanded while a corresponding sweep of motor speed ratio of the variator is recorded. The transmission is engaged into a locked mode providing a fixed output speed and a second hydraulic pressure sweep to the hydraulic actuator is commanded, and a corresponding sweep of variator output torque is recorded during this sweep. A torque/pressure map is then constructed relating motor torque, motor speed ratio, and actuator pressure by scaling the sweep of motor speed ratios and the sweep of variator output torque. The resultant map is usable to provide feed forward torque control of the transmission.

Abstract: A calibration system for calibrating a transmission provides a calibrated clutch fill time for an oncoming clutch by activating a parking brake of a machine associated with the transmission and calibrating each clutch by setting a transmission characteristic parameter to an initial value, and then activating a clutch solenoid associated with the clutch. The transmission characteristic is periodically measured, and when the measured value of the transmission characteristic exceeds the initial value for a predetermined number of consecutive periods, the fill time for the clutch is set equal to the time elapsed during the total number of measurement periods minus one less than the predetermined number of consecutive periods.