Patent ID: 8720396
Filing Date: 2014-05-13
Classification: F02B,F02M

Abstract:
1. A compression-ignition “split-cycle” engine comprising: a cylinder block: an expansion cylinder having an expansion piston that is adapted to move alternatively in said expansion cylinder between a top dead center (ETDC) and a bottom dead center (EBDC) by a crankshaft mechanism, said crankshaft mechanism causing always a predetermined position of said expansion piston to correspond to a predetermined crankshaft angle; a compression cylinder having a compression piston that is adapted to move alternatively in said compression cylinder between a top dead center (CTDC) and a bottom dead center (CBDC) according to a predetermined angular phase shift in delay with respect to the crankshaft angle of said expansion cylinder, said compression cylinder arranged adjacent to said expansion cylinder; a cylinder head that closes said compression and expansion cylinders, and in which at least one crossover passageway is provided that connects said cylinders and comprises a compression-sided opening and an expansion-sided opening, said cylinder head comprising at least one intake valve which faces said compression cylinder for introducing a comburent fluid in said compression cylinder and at least one exhaust valve that faces said expansion cylinder for exhaustion of burnt gas exiting from said expansion cylinder; at least one transfer valve arranged at the compression-sided opening of the crossover passageway; a transfer valve gear for causing an open and close movement of said transfer valve at predetermined moments of the alternative cycle of said pistons; an intake valve gear for causing an open and close movement of said intake valve and an exhaust valve gear for causing an open and close movement of said exhaust valve at predetermined moments of the alternative cycle of said pistons; a fuel injector into said crossover passageway or in said expansion cylinder at predetermined moments of the alternative cycle of said pistons so that ignition of the fuel injected is caused upon reaching a temperature of autoignition by compression; wherein said crossover passageway defines a single combustion chamber in combination with said expansion cylinder with which it is in constant communication, wherein said transfer valve gear is arranged to open said transfer valve in advance with respect to the crankshaft angle of said ETDC, with an advance open movement higher or equal to 20° of crankshaft angle, in such a way that: from the opening instant of said transfer valve up to reaching said ETDC, there is a substantial equalization of instantaneous pressure between said compression cylinder and said expansion cylinder, and between said ETDC and said CTDC, a substantially total transfer occurs of said comburent fluid between said compression cylinder and said expansion cylinder through said crossover passageway; and wherein said fuel injector is arranged to inject said fuel substantially starting from the achievement of said ETDC by said expansion piston, such that said injection of fuel occurs simultaneously to the transfer of said comburent fluid through said crossover passageway.