An oil cooling structure of an engine is provided that is capable of enhancing cooling performance of oil while preventing an increase in number of components or an increase in required space from being involved as much as possible. In an oil cooling structure of an engine in which a transmission case is attached to one end wall of an engine body, and a transmission mechanism for an accessory drive is provided in the transmission case, the transmission case is formed into a potlid-shaped body having a plurality of rib walls along a front-rear direction, and is attached to an engine front wall with an engine cooling fan, and case inner chamber portions partitioned by the rib walls in the transmission case are configured as a transporting passage of oil circulated by an oil pump.

A cylinder liner is provided that includes a cylinder bore capable of housing a piston, a top end having an annular flange, a first cylindrical section, a second cylindrical section, and an annular ridge that separates the first cylindrical section and the second cylindrical section. When employed in an a liner bore of an engine bock, the cylinder liner provides for two channels that allow for coolant to be supplied to the cylinder liner.

An air-cooled internal combustion engine including a crankshaft rotating about a crankshaft axis, a first cylinder having a first cylinder head, a second cylinder having a second cylinder head, and a blower assembly. The blower assembly includes a blower housing, a first fan, and a second fan. The first fan is positioned proximate the first cylinder and the second fan is positioned proximate the second cylinder. The first fan and the second fan are each received within the blower housing.

An engine includes: a cylinder block in which a cooling water passage is formed; an oil cooler accommodated in an accommodation part provided in the cooling water passage and having a plurality of cores for cooling an engine oil; a first oil pipe and a second oil pipe configured to support an oil inflow port and an oil ejection port of each of the cores; a cooling water inflow port provided in a lower portion of one end portion of the accommodation part relative to a front-and-rear direction; a cooling water outflow port provided in an upper portion of the accommodation part; and a cooling water inflow passage having an inclined portion inclined downward and connecting to the cooling water inflow port.

In an internal combustion engine that includes a cylinder block and a cylinder head, and has a cam chain chamber on a side of the cylinder block, a beam member that traverses the cam chain chamber is disposed in the cam chain chamber.

A cooling system including a first sheet steel item having a first surface configured to accommodate one or more objects to be cooled, and a second surface joined to a first surface of a second sheet steel item forming a shell. The items may be joined by a weld, a rivet or a plurality thereof. At least one of the second surface of the first sheet steel item and the first surface of the second sheet steel item may be formed to produce one or more conduits for forming one or more channels, whereby said joining forms said channels for coolant in a space between the second surface of the first sheet steel item and the first surface of the second sheet steel item.

A cylinder block has a different amount of oil supply for each journal, in which a plurality of bearing saddles are arranged at intervals and main bearings, which support main journals of a crank shaft, are respectively mounted to the plurality of bearing saddles. The bearing saddles comprise oil galleries formed in the cylinder block. Oil chambers are recessed from surfaces of the plurality of bearing saddles, to which an oil is supplied through the oil galleries, and communicate with end portions of the oil galleries to store the oil supplied from the oil galleries. The main bearings have oil holes through which the oil introduced into the oil chambers flow to the main journals. The amount of oil supplied to the main journals is determined according to an overlapped amount between the oil chambers and the oil holes.

An engine-driven working machine capable of suppressing vibration, and further securing output power of an engine is provided. An engine-driven working machine 10 is a generator in which an outer case 12 is formed to be substantially rectangular in plan view that extends in a longitudinal direction, and an engine 15 is housed in an inside 13 of the outer case 12. In the generator 10, a crankshaft 41 is disposed to intersect the longitudinal direction of the outer case 12. Further, an intake port 44 and an exhaust port 45 are disposed in the longitudinal direction of the outer case 12. Furthermore, a carburetor 61 is disposed at a side of the intake port 44, and a muffler 67 is disposed at a side of the exhaust port 45.

An air-cooled internal combustion engine including a crankshaft rotating about a crankshaft axis, a first cylinder having a first cylinder head, a second cylinder having a second cylinder head, and a blower assembly. The blower assembly includes a blower housing, a first fan, and a second fan. The first fan is positioned proximate the first cylinder and the second fan is positioned proximate the second cylinder.

An engine according to the present disclosure includes: a crankcase which supports a crankshaft of the engine; a cylinder which is removably connected to the crankcase and protrudes from the crankcase in a cylinder axis direction; a cooling fan which is attached to the crankshaft and rotates in conjunction with the crankshaft; and a cover which guides cooling air generated by the cooling fan to an outer surface of the cylinder. The cover includes an opening part which allows a portion of the cooling air to flow toward an outer surface of the crankcase.