This heat exchanger is provided with an inner tube 2, a first flow passage 3 formed inside the inner tube 2, an outer tube 4 disposed coaxially with the inner tube 2 on the radially outer side thereof, a second flow passage 5 formed between the inner tube 2 and the outer tube 4, annular separating walls P1 to P4 which divide the second flow passage 5 into a plurality of spaces S1 to S5 in the axial direction of the outer tube 4, and space outlets E formed in one location in the circumferential direction of each separating wall P1 to P4, wherein the spaces S1 to S5 are configured to cause a second fluid to swirl about second axes Y perpendicular to a first axis X positioned at the center of the outer tube 4.

An improved blow-by gas return structure minimizes the occurrence of a drawback caused by freezing at a low temperature by bringing a state where freezing minimally occurs in a blow-bay gas passage such as a pipe disposed outside an engine. The blow-by gas return structure is configured such that a blow-by gas is introduced into an intake manifold through an inner passage formed in a head cover. The blow-by gas return structure includes an outer pipe which connects a blow-by gas outlet of the head cover and a blow-by gas inlet of a main pipe of the intake manifold in a communicable manner, and a temperature elevating mechanism configured to elevate a temperature of the blow-by gas inlet. The temperature elevating mechanism is configured such that a cooling water transfer passage is formed in a portion of the blow-by gas inlet of the main pipe.

In an internal combustion engine, the cylinder block includes a first blowby gas passage and a first oil return passage. The cylinder head includes a second blowby gas passage connecting the first blowby gas passage with a connection passage connected with a gas-liquid separator, an oil return chamber separated from a valve operating chamber and the second blowby gas passage by first and second partition walls, respectively, and provided with a first oil return hole connected with the gas-liquid separator, and a second oil return passage connecting the valve operating chamber with the first oil return passage. The first partition wall is formed with a second oil return hole connecting the oil return chamber with the valve operating chamber. The second partition wall is formed with a ventilation hole connecting the oil return chamber with the second blowby gas passage at a higher position than the second oil return hole.

Apparatuses, systems and methods are disclosed including an internal combustion engine. The internal combustion engine can include an engine block defining a combustion cylinder and a crankcase, a piston moveable within the combustion cylinder; a cylinder head coupled to the engine block adjacent to and in fluid communication with the combustion cylinder, and a purge system. The purge system can be in fluid communication with the crankcase. The purge system can supply air to the crankcase and to the cylinder head. The purge system can comprise a valve cover coupled to the cylinder head, a breather coupled to the valve cover, and a fumes disposal line coupled with the breather. The fumes disposal line can transport fumes from the breather and away from the cylinder head.

Apparatuses, systems and methods are disclosed including an internal combustion engine. The internal combustion engine can include an engine block defining a combustion cylinder and a crankcase, a piston moveable within the combustion cylinder; a cylinder head coupled to the engine block adjacent to and in fluid communication with the combustion cylinder, and a purge system. The purge system can be in fluid communication with the crankcase. The purge system can supply air to the crankcase and to the cylinder head. The purge system can comprise a valve cover coupled to the cylinder head, a breather coupled to the valve cover, and a fumes disposal line coupled with the breather. The fumes disposal line can transport fumes from the breather and away from the cylinder head.

A crankcase ventilation system is provided for an internal combustion engine that includes a crankcase. An internal combustion engine including such a system is also provided.

This heat exchanger is provided with an inner tube 2, a first flow passage 3 formed inside the inner tube 2, an outer tube 4 disposed coaxially with the inner tube 2 on the radially outer side thereof, a second flow passage 5 formed between the inner tube 2 and the outer tube 4, annular separating walls P1 to P4 which divide the second flow passage 5 into a plurality of spaces S1 to S5 in the axial direction of the outer tube 4, and space outlets E formed in one location in the circumferential direction of each separating wall P1 to P4, wherein the spaces S1 to S5 are configured to cause a second fluid to swirl about second axes Y perpendicular to a first axis X positioned at the center of the outer tube 4.

A crankcase ventilation system is provided for an internal combustion engine that includes a crankcase. An internal combustion engine including such a system is also provided.

In an internal combustion engine, the cylinder block includes a first blowby gas passage and a first oil return passage. The cylinder head includes a second blowby gas passage connecting the first blowby gas passage with a connection passage connected with a gas-liquid separator, an oil return chamber separated from a valve operating chamber and the second blowby gas passage by first and second partition walls, respectively, and provided with a first oil return hole connected with the gas-liquid separator, and a second oil return passage connecting the valve operating chamber with the first oil return passage. The first partition wall is formed with a second oil return hole connecting the oil return chamber with the valve operating chamber. The second partition wall is formed with a ventilation hole connecting the oil return chamber with the second blowby gas passage at a higher position than the second oil return hole.

A vapor separation system including a cooler having an inlet configured to receive an air-oil-water mixture, and an outlet configured to discharge separated oil and water in two different phases of matter. A first sensor is at the outlet of the cooler. A controller is communicatively coupled to the cooler, wherein the controller is configured to receive temperature feedback from the first sensor, and increase or reduce the amount of cooling, with the cooler and based on the temperature feedback, the oil-water mixture to a separation temperature configured to liquefy at least a portion of the oil in the air-oil-water mixture, while maintaining at least a portion of the water in the air-oil-water mixture in a vaporized state.