A piston is provided for an internal combustion engine. The piston may include a cylindrical first piston portion having a first diameter, a cylindrical second piston portion of the first diameter, and a cylindrical third piston portion of a second diameter less than the first diameter located between the first piston portion and the second piston portion. The first piston portion may be configured such that prior to assembly, the first piston portion is separate from the second piston portion. The piston may also include a continuous, gapless piston ring circumscribing the third piston portion, where the piston ring may be configured such that when heated the piston ring deforms in an axial direction of the piston.

A piston is provided for an internal combustion engine. The piston may include a cylindrical first piston portion having a first diameter, a cylindrical second piston portion of the first diameter, and a cylindrical third piston portion of a second diameter less than the first diameter located between the first piston portion and the second piston portion. The first piston portion may be configured such that prior to assembly, the first piston portion is separate from the second piston portion. The piston may also include a continuous, gapless piston ring circumscribing the third piston portion, where the piston ring may be configured such that when heated the piston ring deforms in an axial direction of the piston.

A method of operating an internal combustion engine having a housing, a piston mounted in the housing for complex motion about a plurality of axes and coupled to a shaft, and wherein occur phases of compression, combustion, and expansion in the housing, and wherein, in the compression phase, air introduced through an intake port into the housing is compressed by reducing volume of a compression chamber in the housing from an initial volume to a second volume that is less than the initial volume, and in the expansion phase, byproducts of combustion expand from the second volume to a third volume that is greater than the initial volume.

An engine includes a compression chamber that intakes and compresses working fluid; an expansion chamber that expands and exhausts working fluid; and a transfer chamber that receives working fluid from the compression chamber and transfers working fluid to the expansion chamber, wherein an internal volume of the transfer chamber decreases during the transfer of working fluid.

An engine includes a compression chamber that intakes and compresses working fluid; an expansion chamber that expands and exhausts working fluid; and a transfer chamber that receives working fluid from the compression chamber and transfers working fluid to the expansion chamber, wherein an internal volume of the transfer chamber decreases during the transfer of working fluid.

An engine with a rotating valve assembly is disclosed. The valve assembly including a housing having an internal cavity, an open top, and an open bottom, the open top and open bottom being in fluid communication with the internal cavity; a valve barrel positioned in the internal cavity and adapted for rotation therein, the valve barrel having an annular peripheral surface and an aperture extending transversely therethrough communicating with the peripheral surface on opposite sides; a first seal assembly positioned in the open top and a second seal assembly positioned in the open bottom, the first and second seal assemblies each include a seal having a sealing surface in mating engagement with the peripheral surface and an aperture extending therethrough.

A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

The disclosure relates to an engine having a cylinder head which is divided into multiple sections which each delimit a combustion chamber of a cylinder of the engine and which each comprise inlet and outlet ducts, inlet and outlet valves, and a spark device which is fastened in a through hole of the cylinder head section, for at least one cylinder head section a throttle flap being provided for completely closing the corresponding inlet duct in the event of a deactivation of the associated cylinder. In the at least one cylinder head section, a first gas flow duct is formed between the through hole and the outlet duct, and the spark device is in the form of a rotary slide valve with integrated spark electrodes and is configured to selectively either keep the first gas flow duct closed or connect said first gas flow duct to the associated combustion chamber.

The disclosure relates to an engine having a cylinder head which is divided into multiple sections which each delimit a combustion chamber of a cylinder of the engine and which each comprise inlet and outlet ducts, inlet and outlet valves, and a spark device which is fastened in a through hole of the cylinder head section, for at least one cylinder head section a throttle flap being provided for completely closing the corresponding inlet duct in the event of a deactivation of the associated cylinder. In the at least one cylinder head section, a first gas flow duct is formed between the through hole and the outlet duct, and the spark device is in the form of a rotary slide valve with integrated spark electrodes and is configured to selectively either keep the first gas flow duct closed or connect said first gas flow duct to the associated combustion chamber.