A crankshaft bearing structure is provided, in which a crankshaft includes a first crank journal and a second crank journal, and a crank pin disposed therebetween. First upper-and-lower journal bearings and second upper-and-lower journal bearings are attached to the respective crank journals, and each upper bearing includes an oil hole connected to an oil passage to supply oil to between the crank journal and the journal bearings. An in-shaft oil passage is formed in the crankshaft to draw oil from an outer circumferential surface of the second crank journal to an outer circumferential surface of the crank pin. The second upper journal bearing has, on an inner circumferential surface thereof, a circumferential groove connected to the oil hole. The oil is supplied to between the first upper-and-lower journal bearings and the first crank journal, only through a passage passing through the oil hole of the first upper journal bearing.

An internal combustion engine includes an engine lubrication fluid storage system with a primary storage volume and a secondary storage volume that is separate from the primary storage volume. The secondary storage volume is linked to the primary storage volume with a fluid flow path that is throttled so that lubrication fluid is stored in the secondary storage volume during engine operation, and drains from the secondary storage volume to the primary storage volume when the engine is not running.

An internal combustion engine has a casing and a piston arrangement including a piston coupled to a track. The track is coupled to a shaft and has an inner cam surface and an outer cam surface. The piston is coupled to the track by followers which run on the respective inner and outer cam surfaces of the track to control motion of the piston. A sliding element is connected to the piston and extends below the piston head having a profiled slider surface which engages a corresponding profile in the casing. Also, the casing includes at least two plates having a cutout for receiving the track and a bore for receiving the shaft, and at least two end plates coupled transverse to the plates. At least one cylinder bore is formed in the end plates, and the piston is arranged to move in reciprocating motion in the cylinder bore.

A crankshaft and conrod assembly (100) comprising a crankshaft (110) and a conrod (150), wherein the crankshaft (110) comprises at least one main journal (111) and one crankpin journal (112), where the crankshaft (110) is provided with an oil supply structure for supplying the crankpin journal (112) with lubrication oil and the conrod (150) with an oil pressure, wherein the oil supply structure comprises: an oil supply conduit (113) provided between the main journal and the crankpin journal (112), at least a first and a second oil supply opening (114, 115) provided at the crankpin journal (112), and a connection point (116) where the oil supply conduit (113) connects to the first and second oil supply opening (114, 115).

A crankshaft oil supply structure includes: an upper engine block having upper end saddles positioned at both ends thereof and an upper crank saddle positioned between the upper end saddles; a lower engine block formed with a plurality of lower crank saddle; an upper end bearing formed with an end bearing hole and mounted on each of the upper end saddles; an upper main bearing formed with a main bearing hole and mounted on the upper crank saddle; a lower bearing mounted on each lower crank saddle of the plurality of lower crank saddles; and a crankshaft formed with an end journal supported by the upper end bearing, a main bearing journal supported by the upper main bearing, and a crank pin journal. In particular, the main bearing hole is larger than the end bearing hole.

A seal system for a bearing compartment of a gas turbine engine includes an annular rotating seal seat in contact with the seal element to form a dry seal interface therebetween to separate am oil-wetted zone from a dry zone. The annular rotating seal seat forms a dry zone annular space adjacent to the annular seal element and the rotating component. The annular rotating seal seat having an oil return passageway through the rotating seal seat to provide a communication path from the dry zone annular space outboard of the rotating component back to the oil-wetted zone.

A lubricating oil supply structure includes: a shaft; a bearing supporting the shaft and having an oil supply port, through which lubricating oil is supplied to between the shaft and the bearing, and an oil introduction port, through which the lubricating oil is introduced; a first oil passage, connected to the oil supply port, distributing the lubricating oil from an oil pump toward the oil supply port; a second oil passage, connected to the oil introduction port, supplying the lubricating oil introduced through the oil introduction port to a supply destination; a connection oil passage, formed by a gap between the bearing and the shaft, connecting between the first oil passage and the second oil passage, and a throttle portion, formed on a part of the connection oil passage, suppressing a flow of the lubricating oil from the oil supply port toward the oil introduction port.

An internal combustion engine has an oil circuit for supplying oil to powertrain components and cylinder head components of the internal combustion engine. At least one oil pump and one oil filter module are incorporated into the oil circuit. The oil circuit branches into a powertrain oil gallery and a cylinder head oil gallery in the oil filter module or downstream of the oil filter module in a flow direction. The oil circuit is designed so that a lower oil pressure prevails in the powertrain oil gallery than in the cylinder head oil gallery.

A crankshaft and conrod assembly (100) comprising a crankshaft (110) and a conrod (150), wherein the crankshaft (110) comprises at least one main journal (111) and one crankpin journal (112), where the crankshaft (110) is provided with an oil supply structure for supplying the crankpin journal (112) with lubrication oil and the conrod (150) with an oil pressure, wherein the oil supply structure comprises: an oil supply conduit (113) provided between the main journal and the crankpin journal (112), at least a first and a second oil supply opening (114, 115) provided at the crankpin journal (112), and a connection point (116) where the oil supply conduit (113) connects to the first and second oil supply opening (114, 115).

A control device controls an internal combustion engine including: an elastic wave sensor arranged and configured to output a signal responsive to the strength of an acoustic emission wave produced at a sliding portion; and a variable oil pump. The control device is configured to execute an oil pressure control such that the oil pressure approaches a target oil pressure according to an engine operating condition. This oil pressure control includes a first pressure-increase processing executed where an AE correlation value correlated with the strength or occurrence frequency of the acoustic emission wave detected by the elastic wave sensor is greater than a first threshold value. The first pressure-increase processing increases the target oil pressure associated with a first engine operating condition present when the AE correlation value becomes greater than the first threshold value, as compared to when the AE correlation value is not greater than that.