A drive apparatus includes a first variable speed drive mechanism, a second variable speed drive mechanism, a first output half shaft, and a second output half shaft. The first variable speed drive mechanism includes a first reduction gear, a first planetary gear system, and a first brake mechanism. The second variable speed drive mechanism includes a second reduction gear, a second planetary gear system, and a second brake mechanism. The first planetary gear system includes a first sun gear, a first gear ring, a first planetary gear, and a first planet carrier. The first reduction gear is engaged with the first sun gear.

A system is configured to manage motor engagement in a vehicle by determining to engage a disengaged motor shaft with a drivetrain, and in response, activating a feedback controller based on a speed of the motor shaft and activating a feedforward controller. The system determines at least one metric for modifying an output of the feedforward controller. The at least one metric is based on the speed of the motor shaft and the desired speed, and may be applied as a gain to the output of the feedforward controller. The system generates a command based on the feedback controller, the feedforward controller, and the at least one metric, and causes the motor shaft and the drivetrain to be engaged based on the speed of the motor shaft and the desired speed. The system nulls output of the feedforward controller as the speed of the motor shaft approaches the desired speed.

A system in a vehicle includes a current regulator to obtain current commands from a controller based on a torque input and provide voltage commands and an inverter to use the voltage commands from the current regulator and direct current (DC) supplied by a battery to provide alternating current (AC). An electric traction motor provides drive power to a transmission of the vehicle based on injection of the AC from the inverter. A current observer obtains measured input current signals based on the AC for a current control cycle and provides predicted current signals for a next control cycle to the current regulator using a model. The current observer includes a controller to check output of the model against the measured input current signals. The current observer tunes parameters of the controller and the model used to generate the predicted current signals based on the measured input current signals.

A dual drive unit may include two motors, two power transfer mechanisms, and two output shafts. The output shafts are co-linear. The dual drive unit may include two single drive units, which may be similar to each other, coupled together at a joint, which may optionally include a clutch. A drive unit may be modular, and various components may be combined to provide power to an output shaft. For example, a drive unit may include a differential at a first interface, which may be removable, and two drive units may be coupled together at the first interface. A drive unit may have a Z configuration, wherein a motor on a first side of a vehicle powers a wheel on an opposite side of the vehicle.

An illustrative dual power inverter module includes a detection circuit configured to detect loss of low voltage DC electrical power supplied to a controller for a first power inverter and a second power inverter of a drive unit for an electric vehicle. A first backup power circuit is associated with the first power inverter and a second backup power circuit is associated with the second power inverter. Each backup power circuit is configured to convert high voltage DC electrical power to low voltage DC electrical power responsive to detection of loss of low voltage DC electrical power supplied to the controller. Three-phase short circuitry is configured to apply a same fault action to the first power inverter and the second power inverter responsive to detection of loss of low voltage DC electrical power supplied to the controller, wherein the same fault action includes applying equalized torque to each axle operatively coupled to the drive unit.

A method for controlling an electric vehicle driven by a plurality of electric motors including a first electric motor, in which a lubricant, which is used for lubricating the electric motors and power transmission systems therefor, is used for cooling the electric motors is provided. The method includes setting torque distributions for the plurality of electric motors on the basis of a driving force required by the electric vehicle controlling the drive of the plurality of electric motors on the basis of the set torque distributions and circulating intermittently the lubricant used for cooling the first electric motor when the torque distribution set for the first electric motor is smaller than a predetermined value which is regarded as a reference value.

An automotive propulsion system has a transmission including an output shaft, a variable voltage converter including an inductor disposed within a housing of the transmission such that transmission fluid within the housing contacts the inductor to cool the inductor, and a controller that maintains a magnitude of current through the inductor to less than a limit value that is defined by a speed associated with the output shaft and a switching frequency of the variable voltage converter.

A dual drive unit may include two motors, two power transfer mechanisms, and two output shafts. The output shafts are co-linear. The dual drive unit may include two single drive units, which may be similar to each other, coupled together at a joint, which may optionally include a clutch. A drive unit may be modular, and various components may be combined to provide power to an output shaft. For example, a drive unit may include a differential at a first interface, which may be removable, and two drive units may be coupled together at the first interface. A drive unit may have a Z configuration, wherein a motor on a first side of a vehicle powers a wheel on an opposite side of the vehicle.

A drive system includes a first drive train and a second drive train coupled by a differential assembly. Each drive train include a motor, an output gear, and a clutch assembly that engages and disengages the output gear from respective halfshafts. The differential assembly is configured to couple the first and second halfshafts, and connect/disconnect the first output gear and the first halfshaft. The differential assembly includes, for example, side gears, a spider gearset, and an actuator for engaging and disengaging the differential casing from the first output gear. A control system is configured to actuate actuators of clutch assemblies and/or a differential assembly to achieve one or more drive modes for each drive axis. The control system determines the first drive mode, controls the clutch assemblies and differential assemblies, and controls one or more motors. The drive modes include, for example, torque vectoring, fully locked, single motor, and neutral.

The present invention discloses a liquid-cooled integrative power system for electric forklift and a control method thereof. It includes an integrated transmission gearbox, an integrated motor controller, an oil pump and a vehicle controller. The integrated transmission gearbox includes a drive motor transmission mechanism and an oil pump motor transmission mechanism. The integrated motor controller includes a control unit for a drive motor and a control unit for an oil pump motor. The integrated transmission gearbox, the integrated motor controller, the drive motor, the oil pump motor, the oil pump and the vehicle controller are completely integrated and mounted to form the liquid-cooled integrative power system for electric forklift. The vehicle controller comprehensively controls the integrative power system.