A blow-by gas device of a supercharger-equipped engine includes a blow-by gas passage that introduces blow-by gas into an intake passage via a positive crankcase ventilation (PCV) valve. A supercharger has a supercharger rotor provided integrally with a rotation shaft rotatably supported on a bearing part. A space communicating with the bearing part is connected to a communication passage. The communication passage guides the blow-by gas into the space.

A lubrication structure for an internal combustion engine includes a crankcase, an oil pump, and a relief valve. The crankcase is configured by connecting an upper crankcase on a mating surface of a lower crankcase, and has an oil pan. The oil pump and the relief valve are installed in the lower crankcase. The oil pump sucks oil in the oil pan through a suction passage, and discharges the oil into a discharge passage. The relief valve performs a valve-opening operation according to pressure of oil in the discharge passage to return surplus oil in the discharge passage to the suction passage through a surplus passage. These passages are formed in the lower crankcase. A relief valve housing section housing the relief valve, and the surplus passage allowing the relief valve housing section and the suction passage to communicate with each other, are provided to communicate with the mating surface.

A bearing supporting an end of a layshaft in an internal combustion engine is lubricated by injection of oil through a flange that mounts the layshaft on the engine. A pressure responsive flow control valve controls delivery of oil through the flange to the bearing. A backflow prevention adapter prevents back flow of oil to the engine's oil pump.

An engine oil passage structure for an engine contributing to downsizing the engine and achieving protection of an oil passage against external forces is provided. Provided is an oil passage structure for an engine installed in a small vehicle, the engine including an engine body formed of a crankcase and a cylinder block and a cylinder head stacked inclined vehicle frontward on the crankcase, the crankcase, the cylinder block, and the cylinder head being integrally fastened. The oil passage structure includes, near a bent part formed by a case front wall of the crankcase and a cylinder front wall of the cylinder block forming a valley part by an obtuse angle, a right-left direction oil passage extending in a right-left direction along the valley part.

A valve opening/closing timing control device that sets a relative rotation phase between a driving-side rotating body and a driven-side rotating body using a driving force of an electric actuator is compactly configured. The device is provided with: a first bearing disposed between an inner periphery of the driven-side rotating body and an eccentric member; a second bearing disposed between the eccentric member and an input gear on a side of the first bearing away from a camshaft in a direction along a rotational axis; and a front plate fixed to the driving-side rotating body on a side of the second bearing away from the camshaft. An Oldham coupling is disposed on the side away from the camshaft of both the first bearing and the second bearing in the direction along the rotational axis.

An internal combustion engine has a lower link rotatably mounted to a crankpin of a crankshaft, an upper link having a first upper link end rotatably connected to a piston pin of a piston and a second upper link end rotatably connected to a first lower link end side of the lower link through a first connecting pin, and a control link having a first control link end supported on a cylinder block and a second control link end rotatably connected to a second lower link end side of the lower link through a second connecting pin. When viewed in an axial direction of the crankshaft, the second connecting pin is arranged to swing along a lateral direction substantially perpendicular to a center axis of a cylinder of the internal combustion engine.

An internal combustion engine has a lower link rotatably mounted to a crankpin of a crankshaft, an upper link having a first upper link end rotatably connected to a piston pin of a piston and a second upper link end rotatably connected to a first lower link end side of the lower link through a first connecting pin, and a control link having a first control link end supported on a cylinder block and a second control link end rotatably connected to a second lower link end side of the lower link through a second connecting pin. When viewed in an axial direction of the crankshaft, the second connecting pin is arranged to swing along a lateral direction substantially perpendicular to a center axis of a cylinder of the internal combustion engine.

A lubrication structure for an internal combustion engine includes a crankcase, an oil pump, and a relief valve. The crankcase is configured by connecting an upper crankcase on a mating surface of a lower crankcase, and has an oil pan. The oil pump and the relief valve are installed in the lower crankcase. The oil pump sucks oil in the oil pan through a suction passage, and discharges the oil into a discharge passage. The relief valve performs a valve-opening operation according to pressure of oil in the discharge passage to return surplus oil in the discharge passage to the suction passage through a surplus passage. These passages are formed in the lower crankcase. A relief valve housing section housing the relief valve, and the surplus passage allowing the relief valve housing section and the suction passage to communicate with each other, are provided to communicate with the mating surface.

A valve train assembly is provided, comprising an exhaust camshaft having an exhaust lobe and a brake lobe, an exhaust lever mounted adjacent the exhaust lobe, a brake lever mounted adjacent the brake lobe, wherein the exhaust lever is coupled to the brake lever to provide simultaneous movement of the exhaust lever and the brake lever in response to the exhaust lobe and independent movement of the brake lever in response to the brake lobe.

A pump, particularly a vacuum pump for boosting braking power on a motor vehicle, including a housing, a rotor mounted in the housing so as to be rotatable, an oil riser groove arranged in the housing in the area of the rotor mounting, and a transverse bore arranged in the rotor transverse to the longitudinal axis of the rotor and which can be connected to the oil riser groove. The rotor mounting area is connected to an oil supply bore. The transverse bore interacts with an axial bore in the rotor which leads to a coupling section within the rotor, in which a coupling is arranged which can be engaged by a fastener having a central bore running parallel to the longitudinal axis of the rotor.