An oil passageway structure for IC engines includes a generator provided on one end side of a crankshaft, a generator cover that covers the generator and is fixed to an engine crankcase, a protective cover provided outside the generator cover and a water pump attached to an outer surface of the protective cover and having a drive shaft coaxially connected to one end of the crankshaft. The generator cover includes oil passageways that supply engine oil from the crankcase to the generator, and a generator cover-side guide portion that flows out engine oil collected from a generator housing space housing the generator toward the protective cover, and the protective cover includes a protective cover-side guide portion that guides and supplies the engine oil flowing out from the generator cover-side guide portion to the drive shaft of the water pump.

The present disclosure is directed towards an engine assembly comprising a crankcase, a crankshaft, a lubrication system and fluid guide arrangement. During rotation the crankshaft is configured to drive a crankcase fluid flow in a crankcase chamber. The lubrication system comprises a lubricant drain for a drain fluid flow therethrough extending to a drain aperture at the crankcase chamber. The fluid guide arrangement is located adjacent or in proximity to the drain aperture. The fluid guide arrangement is configured for guiding crankcase fluid flow away from the drain aperture and/or for reducing the pressure of the crankcase fluid flow past the drain aperture, such that drain fluid flows from the lubricant drain.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

An internal combustion engine includes a one-piece cylinder block casting, a flywheel supported for rotation at a front block end, and a back gear train supported for rotation at a back block end. Cast-in pump inlet and outlet passages are formed in the cylinder block casting and open in a pump mounting face at the back block end. An oil pump is clamped to the pump mounting face and includes a pump inlet and a pump outlet fluidly connected, respectively, to the cast-in pump inlet passage and the cast-in pump outlet passage.

An internal combustion engine includes a one-piece cylinder block casting, a flywheel supported for rotation at a front block end, and a back gear train supported for rotation at a back block end. Cast-in pump inlet and outlet passages are formed in the cylinder block casting and open in a pump mounting face at the back block end. An oil pump is clamped to the pump mounting face and includes a pump inlet and a pump outlet fluidly connected, respectively, to the cast-in pump inlet passage and the cast-in pump outlet passage.

A seal system for a bearing chamber (22) of a turbomachine includes the baffle element (70) encircling the axis (25) of the machine. The baffle element is formed with front surface including both a recess (73) which defines a circumferentially-extending oil-receiving channel (74), and an oil-deflecting surface (78) on a gutter (77). The channel decreases in cross-sectional area close to the oil-deflecting surface, and a circular line which is within the channel distant from the gutter, intersects with the oil-deflection surface. This forces the oil to change direction at the gutter, and urges the oil radially outward. Thus, a high rotational velocity of the body of oil may be maintained, whilst improving the drainage efficiency of the seal system at the gutter.

An oil supply structure which supplies lubricating oil to a portion to be lubricated in a casing, the oil supply structure comprises an opening portion provided on a wall portion of the casing which corresponds to a shaft end portion of a rotary shaft supported by a bearing in the casing, and an oil passage configured to provide communication from the opening portion to at least the bearing.

A straddle vehicle includes: a prime mover; a hydraulically actuated main clutch; an oil control valve unit; a power unit case accommodating at least the main clutch; an oil pan mounted beneath the power unit case; a clutch-dedicated pump; a primary filter disposed in an oil passage between the oil pan and the clutch-dedicated pump; and a secondary filter disposed in an oil passage between the clutch-dedicated pump and the oil control valve unit. The primary filter and the secondary filter are mounted on a bottom surface of the power unit case and covered from below by the oil pan.

The present invention improves the drainability of lubricating oil at a thrust bearing. The present invention comprises: a rotating shaft; a thrust bearing that is provided to the rotating shaft and restricts the axial-direction movement of the rotating shaft; and an oil reservoir part (20) that has formed therein an oil reservoir space (20a) that is provided to be adjacent to the thrust bearing in the axial direction and to open downward, the oil reservoir space (20a) having formed therein an inclined surface (20aa) that, in a region that is in and below a horizontal plane H that passes through the center of the rotating shaft, protrudes to the thrust bearing side and is inclined along the rotational direction of the rotating shaft.