A Stirling engine including a crosshead mechanism includes a low-pressure space and a high-pressure space. In the high-pressure space, a piston is driven by a heating/cooling cycle of a working fluid. The low-pressure space accommodates a crosshead portion connected to the piston via a piston rod, and a crank mechanism that rotates a crankshaft along with movement of the crosshead portion. A high-pressure gas seal in which a lip angle of a seal lip on the high-pressure side is smaller than that on the low-pressure side is provided around the piston rod at a partition between the low-pressure space and the high-pressure space.

Methods and systems are provided for a cooling arrangement. In one example, a system comprises a separator arranged in a block coolant jacket. The separator fluidly separates an upper portion of the block coolant jacket from a lower portion of the block coolant jacket.

A cylinder block assembly may include a cylinder block, a cylinder body disposed in the cylinder block, with a plurality of cylinder bores formed in the cylinder body, a fluid jacket, which is formed between an inner circumferential surface of the cylinder block and an outer circumferential surface of the cylinder body, and through which coolant flows, and a block insert disposed in the water jacket and configured to guide a flow of coolant, wherein the cylinder block may include a second block coolant outlet, which is formed at a second side in a surface of an exhaust side of the cylinder block, and through which the coolant in the water jacket is discharged, and wherein the exhaust side may include a side at which combustion gas is exhausted out of the cylinder body.

An HT cooling system cools at least a cylinder block with HT cooling water. An LT cooling system cools an intake port with LT cooling water that is at a lower temperature than the HT cooling water. A controller performs an ignition retard control that involves correcting the ignition timing based on the result of detection of a knock by a knock sensor, and a cooling enhancement control that involves enhancing cooling by the LT cooling system in the case where a knock is detected compared with the case where no knock is detected. The way of cooling by the HT cooling system is unchanged whether a knock is detected.

A water jacket spacer is provided that ensures that a cylinder bore wall has a uniform temperature. When a contact member that comes in contact with the all surface of a groove-like coolant passage is provided to either or both of the inner wall side and the outer wall side of the water jacket spacer along the longitudinal direction of the water jacket spacer to divide the groove-like coolant passage into an upper part and a lower part, it is possible to separately control the flow rate of the coolant that flows through the upper passage of the groove-like coolant passage, and the flow rate of the coolant that flows through the lower passage of the groove-like coolant passage, and separately adjust the degree of cooling with respect to the upper part and the lower part of the cylinder bore wall.

A water jacket coolant passage division member includes: a partition member that has a planar shape that conforms to a groove-like coolant passage provided to a cylinder block that is provided to an internal combustion engine; an inner-side rubber member that is provided to an inner side of the partition member, and comes in contact with a cylinder bore-side wall surface of the groove-like coolant passage; and an outer-side rubber member that is provided to an outer side of the partition member, and comes in contact with an outer wall surface of the groove-like coolant passage. An internal combustion engine in which a cylinder bore wall has a uniform temperature can be provided by utilizing the water jacket coolant passage division member.

An engine cooler capable of suppressing a piston slap sound is provided. The engine cooler includes a cylinder block including a cylinder barrel and a water jacket, and a spacer stored in the water jacket, the water jacket surrounds the cylinder barrel, and the spacer encloses the cylinder barrel. Given that a width direction of the cylinder block is a lateral direction, a pressed member is pressed between the cylinder barrel and the spacer on lateral sides of the cylinder barrel, and a lower end of the pressed member is disposed above a lower end of each of right and left skirts of a piston located at a top dead center.

An internal combustion engine includes: an engine body; an exhaust pipe fastened to the engine body; an engine body cooling water passage provided in the engine body and having a cooling water injection port and a cooling water discharge port; an exhaust pipe cooling water passage provided in the exhaust pipe; a supply passage that connects the engine body cooling water passage with the exhaust pipe cooling water passage such that cooling water flows from the engine body cooling water passage to the exhaust pipe cooling water passage through the supply passage; and a return passage that connects the engine body cooling water passage with the exhaust pipe cooling water passage such that the cooling water flows from the exhaust pipe cooling water passage to the engine body cooling water passage through the return passage.

Methods and systems are provided for a water jacket diverter. In one example, the water jacket diverter has a continuous upper rail with a profile including curved and linear portions where the profile of the upper rail is optimized to moderate coolant flow through the water jacket. The water jacket diverter further includes at least one protrusion extending outwards from an outer face of the diverter, the at least one protrusion positioned in front of a coolant inlet.

The present disclosure provides a split cooling apparatus for an internal combustion engine, the apparatus including: a base inserted into a water jacket of a cylinder block, the base surrounding an outside of a cylinder along a shape of the cylinder; an insertion groove formed on the base by being depressed into an inner surface of the base; and a sealing member inserted into the insertion groove, wherein when a temperature of cooling water supplied into the water jacket reaches a preset temperature or higher, the sealing member expands so as to close a flow passage between the base and the cylinder, thereby increasing flow resistance of the cooling water and thus reducing a heat transfer rate of the cylinder.