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US 11,441,526 B1Granted
Engine crank system and method
AssigneeGM Global Technology Operations LLC
InventorsPranjal Sharma, Chandra S. Namuduri, Suresh Gopalakrishnan
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Abstract
Internal combustion engine cranking is carried out including with a limited overlapping of cranking with a starter motor and a starter/generator during at least the initial compression stroke during a cranking cycle.
Claims20
A cranking system for an internal combustion engine, comprising:
- a first electric machine rotatably coupled to a crankshaft of the engine;
- a second electric machine rotatably coupled to the crankshaft of the engine;
- and
- a controller executing an engine cranking cycle, comprising:
- causing the first electric machine to crank the engine beginning from a stopped engine state and ending at a crankshaft angle substantially corresponding to a top dead center combustion position of a first piston undergoing a first compression stroke;
- and
- causing the second electric machine to crank the engine beginning at a crankshaft angle subsequent to a bottom dead center intake position of the first piston undergoing the first compression stroke.
4 more elements
A cranking system, comprising:
- an internal combustion engine including a crankshaft, a flywheel coupled to the crankshaft and a ring gear coupled to the flywheel at a perimeter thereof;
- a starter motor unit including a pinion gear rotatably coupled to an electric motor, the pinion gear being controllably engageable to the ring gear and the electric motor being controllably energizable to cause rotation of the pinion gear;
- a starter/generator unit rotatably coupled to the crankshaft;
- and
- a controller:
- causing the pinion gear to engage with the ring gear and energizing the electric motor to crank the engine beginning from a stopped engine state and ending at a crankshaft angle substantially corresponding to a top dead center combustion position of a first piston undergoing a compression stroke;
- and
- causing the starter/generator unit to crank the engine beginning at a crankshaft angle subsequent to a bottom dead center intake position of the first piston undergoing the compression stroke.
5 more elements
A method of performing an engine cranking cycle, comprising:
- cranking the engine with a starter motor during an initial cranking period beginning from a stopped engine state and ending at a crankshaft angle substantially corresponding to the end of a first compression stroke of a first piston to undergo a compression stroke;
- and
- cranking the engine with a starter/generator beginning no later than at a crankshaft angle during the first compression stroke and continuing until the engine crank cycle ends.
Dependencies are inferred from the claim text.