A drive system for an engine arrangement includes a gear reduction mechanism having at least three separate and rotatable junction elements, the rotation speeds of the junction elements being interdependent but not having a fixed ratio the ones relative to the others, and wherein, in the mounted position, among the junction elements, a first junction element is connected to an engine crankshaft, a second junction element is connected to an accessory pulley which is drivingly connected to an electric machine and at least one accessory, and a third junction element. A free wheel is connected to a non-rotating part of the engine arrangement in the mounted position, and the third junction element is configured to be coupled to the free wheel in a first operating phase of the drive system. The third junction element is further configured to be coupled to the engine crankshaft in a second operating phase.

A combination starter-generator device is provided for a work vehicle having an engine. The starter-generator device includes an electric machine and a gear set configured to receive rotational input from the electric machine and from the engine and to couple the electric machine and the engine in a first power flow direction and a second power flow direction. The gear set is configured to operate a first, second, or third gear ratio in the first power flow direction and a fourth gear ratio in the second power flow direction. At least one clutch is selectively coupled to the gear set to effect the first, second, and third gear ratios in the first power flow direction and the fourth gear ratio in the second power flow direction. A magnetic cam assembly is configured to shift the at least one clutch from a disengaged position into an engaged position.

A combination starter-generator device includes an electric machine and a gear set configured to receive rotational input from the electric machine and from the engine and to couple the electric machine and the engine in a first power flow direction and a second power flow direction. The gear set is configured to operate in one of multiple gear ratios in the first power flow direction and at least one gear ratio in the second power flow direction. The starter-generator device further includes a clutch arrangement with at least one active clutch selectively coupled to the gear set to effect the gear ratios in the first power flow direction and in the second power flow direction. The clutch arrangement further includes at least one drag clutch to apply a drag force on the gear set to slow the electric machine.

A combination starter-generator device is provided for a work vehicle having an engine. The starter-generator device includes an electric machine; and a gear set configured to receive rotational input from the electric machine and from the engine and to couple the electric machine and the engine in a first power flow direction and a second power flow direction. The gear set is configured to operate in one of multiple relatively high-torque, low-speed start gear ratios in the first power flow direction and a relatively low-torque, high-speed gear ratio in the second power flow direction.

A method is provided for starting an internal combustion engine with a driveshaft for a motor vehicle. A starting process is carried out, by which the internal combustion engine is started and thereby transferred from a deactivated state into a powered operation, wherein the starting process is carried out by a pinion starter and by a belt starter, by which the driveshaft is driven during the starting process.

A method is provided for starting an internal combustion engine with a driveshaft for a motor vehicle. A starting process is carried out, by which the internal combustion engine is started and thereby transferred from a deactivated state into a powered operation, wherein the starting process is carried out by a pinion starter and by a belt starter, by which the driveshaft is driven during the starting process.

A first controller includes a start control section and a passage determination section. After activating a second starter to start cranking, the start control section stops the operation of the second starter and starts the motor operation of the first starter at a predetermined timing. The passage determination section determines whether a predetermined passage conditional expression holds after cranking is started by the second starter. The start control section stops the operation of the second starter and starts the motor operation of the first starter if the passage conditional expression holds before the engine passes the first compression top dead center, regardless of whether the engine has passed the first compression top dead center.

A first controller includes a start control section and a passage determination section. After activating a second starter to start cranking, the start control section stops the operation of the second starter and starts the motor operation of the first starter at a predetermined timing. The passage determination section determines whether a predetermined passage conditional expression holds after cranking is started by the second starter. The start control section stops the operation of the second starter and starts the motor operation of the first starter if the passage conditional expression holds before the engine passes the first compression top dead center, regardless of whether the engine has passed the first compression top dead center.

A power control system is provided for a work vehicle with an engine. A combination starter-generator device has an electric machine and a gear set configured to receive rotational input from the electric machine and the engine and to couple the electric machine and the engine in two power flow directions. The gear set operates in one of multiple relatively high-torque, low-speed start gear ratios in one direction, including a first start gear ratio corresponding to a cold engine start mode and a second start gear ratio corresponding to a warm engine start mode, and in a relatively low-torque, high-speed gear ratio in another direction corresponding to a generation mode. First and second clutch assemblies are selectively coupled to the gear set to effect the start gear ratios during the engine start modes. A control valve is fluidly coupled to selectively apply a fluid pressure to the clutch assemblies.

A combination starter-generator device is provided for a work vehicle having an engine. The starter-generator device includes an electric machine and a gear set configured to receive rotational input from the electric machine and from the engine and to couple the electric machine and the engine in a first power flow direction and a second power flow direction. The gear set is configured to operate a first, second, or third gear ratio in the first power flow direction and a fourth gear ratio in the second power flow direction. At least one clutch is selectively coupled to the gear set to effect the first, second, and third gear ratios in the first power flow direction and the fourth gear ratio in the second power flow direction. A magnetic cam assembly is configured to shift the at least one clutch from a disengaged position into an engaged position.