A system and method for controlling engine starting in a hybrid vehicle having first and second electric machines include starting the engine in response to an engine start request using the first electric machine and releasing second electric machine reserved engine starting torque for use in propelling the vehicle. The first electric machine may be controlled to start the engine in response to the first engine start after key-on and when the vehicle speed is below a corresponding threshold, with the second electric machine used when vehicle speed is above the threshold. The first electric machine may be an integrated starter-generator.

A number of variations may include a product including a stator assembly and/or a rotor assembly wherein at least one of the stator assembly and/or rotor assembly includes a central cavity, and at least two clutch assemblies, wherein at least a portion of each of the two clutch assemblies is received in the cavity. A number of variations may include a module wherein a plurality of clutches and electric motor are received in the same housing to form a module wherein the electromagnetic (motor performance and clutch performance can be tested prior to installing the module in a vehicle.

A drive train for a vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device by an electrical power transmission system, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In all modes of operation where the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

A vehicle includes a power source configured to provide drive torque, a front axle, a rear axle, and a transfer case configured to distribute drive torque from the power source between the front axle and the rear axle. The vehicle additionally includes a clutch arranged between the front axle and the transfer case. The clutch has a disengaged state and an engaged state drivingly coupling the transfer case and the front axle. The vehicle also includes a regenerative braking system configured to, in response to a braking request, provide regenerative braking torque to the rear axle. The vehicle further includes a controller. The controller is configured to, in response to a braking request and the clutch being in the disengaged state, control the clutch to shift into the engaged state to couple the regenerative braking system to the front axle and provide regenerative braking torque to the front axle.

A vehicle is operable in three modes of operation. The vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In each of the three modes of operation, whenever the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

A system and method for integrated electrification of vehicle accessories conventionally driven by an internal combustion engine includes an electric motor coupled to a common accessory drive that drive a plurality of accessories, such as a power steering pump, an air conditioning compressor, an air compressor, a thermodynamic heater and/or a coolant pump. The integrated electrified accessory unit preferably has the electric motor, accessory drive and accessories arranged in a common housing which is configured to be mounted to a chassis frame rail of the vehicle, the common housing including wall penetrations which facilitate rapid connection of the accessories to external lines of the vehicle.

A vehicle is operable in three modes of operation. The vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In each of the three modes of operation, whenever the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

A method of operating a first electric machine and a second electric machine in a vehicle drive includes operating the vehicle drive in a first operating mode by operating the first electric machine to regulate electrical power at a bus to maintain a first voltage on the bus and operating the second electric machine to consume electrical power from the bus. The method includes operating the vehicle drive in a second operating mode by operating the first electric machine to consume electrical power from the bus and operating the second electric machine to regulate electrical power at the bus to maintain a second voltage on the bus. A sum of the electrical power regulated by the first electric machine, the electrical power losses, and the electrical power consumed by the second electric machine is zero in the first operating mode and in the second operating mode.

A drive train for a vehicle includes a first electromagnetic device, a second electromagnetic device electrically coupled to the first electromagnetic device by an electrical power transmission system, and an engine coupled to the first electromagnetic device and configured to drive the first electromagnetic device to provide electrical energy. In all modes of operation where the engine drives the first electromagnetic device to provide the electrical energy, the first electromagnetic device operates without providing the electrical energy to an energy storage device.

A vehicle drive includes a gear set, a first motor/generator coupled to the gear set, a second motor/generator at least selectively rotationally engaged with the gear set, and an engine at least selectively coupled to the gear set and at least selectively coupled to the second motor/generator. The second motor/generator is electrically coupled to the first motor/generator by an electrical power transmission system. The first motor/generator and the second motor/generator are electrically coupled without an energy storage device configured to at least one of (a) provide electrical energy to the first motor/generator or the second motor/generator to power the first motor/generator or the second motor/generator and (b) be charged by electrical energy from the first motor/generator or the second motor/generator.