Powertrain for a vehicle and an electromechanical apparatus coupleable to an engine

A powertrain for a vehicle, the powertrain comprising:

• an engine including a housing and a crankshaft at least partially disposed inside the housing, with the crankshaft being rotatable about a longitudinal axis;
• a ring gear disposed outside of the housing and attached to a first distal end of the crankshaft such that the ring gear and the crankshaft are rotatable in unison about the longitudinal axis;
• a crankshaft pulley disposed outside of the housing and coupleable to a second distal end of the crankshaft such that the crankshaft pulley and the crankshaft are rotatable in unison about the longitudinal axis;
• a motor-generator operable in a first mode to start the engine and a second mode after the engine is started;
• wherein the motor-generator includes a motor/generator shaft and a motor/generator pulley coupleable to the motor/generator shaft adjacent to a first end of the motor-generator, with the motor/generator shaft extending out of a second end of the motor-generator, and with the first and second ends of the motor-generator spaced from each other along a first axis, and with the motor/generator pulley and the motor/generator shaft each being rotatable about the first axis, and with the first axis being spaced from the longitudinal axis;
• an endless rotatable device disposed about the crankshaft pulley and the motor/generator pulley to selectively rotate the motor/generator pulley when the motor-generator is in the second mode to selectively transfer torque between the crankshaft and the motor/generator shaft;
• and
• a starter mechanism including a first starter gear coupleable to the motor/generator shaft, wherein the first starter gear is rotatable about a second axis when the motor-generator is in the first mode, with the second axis being spaced from the longitudinal axis, and with the first starter gear being movable along the second axis between a first position engaging the ring gear such that torque is transferred from the motor/generator shaft through the first starter gear and the ring gear to the crankshaft to start the engine, and a second position disengaged from the ring gear after the engine is started to rotatably disconnect the starter mechanism from the ring gear.

An electromechanical apparatus coupleable to an engine including a crankshaft;

• the apparatus comprising:
• a first rotatable element being rotatable about a first axis and a second rotatable element being rotatable about a longitudinal axis, with the first axis spaced from the longitudinal axis;
• an endless rotatable device disposed about the first and second rotatable elements to selectively transfer torque between the first and second rotatable elements;
• a gear set including a ring gear and a first gear each having external teeth and each being rotatable, with the first gear attached to a shaft such that the first gear and the shaft are rotatable about a second axis spaced from the longitudinal axis, with the ring gear coupleable to the crankshaft to transfer torque to the crankshaft when the external teeth of the first gear engage the external teeth of the ring gear to rotate the ring gear;
• a motor-generator including a motor/generator shaft being rotatable about the first axis, with the first rotatable element coupleable to the motor/generator shaft;
• a first coupling device operable for selectively transferring torque between the motor/generator shaft and the crankshaft through the endless rotatable device at a first ratio based on the first and second rotatable elements;
• and
• a second coupling device operable for selectively transferring torque between the motor/generator shaft and the crankshaft through the gear set at a second ratio based on the ring gear and the first gear, with the first and second ratios being different from each other;
• wherein the motor-generator is operable to start the engine by transferring torque directly to the second coupling device.