A camshaft cover, a camshaft assembly, and a double-cylinder engine are provided. The camshaft cover has an integral structure, and includes a first shaft cover portion, a second shaft cover portion, a first connecting portion and a second connecting portion. The first connecting portion and the second connecting portion are connected between the first shaft cover portion and the second shaft cover portion, and spaced apart axially.

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 oil passageway structure for internal combustion engines includes a cylinder head having an inter-bearing wall fluid communication oil passage for providing fluid communication between a plurality of bearing walls to allow oil to flow therebetween. The cylinder head further includes a bearing wall oil passage branched from the inter-bearing wall fluid communication oil passage to supply oil to a bearing surfaces of at least one of the bearing walls. The inter-bearing wall fluid communication oil passage is defined in one of facing side walls. The bearing wall oil passageway is defined in at least one of the bearing walls. The oil passageway structure is thus made up of a reduced number of parts, can be assembled with a reduced number of man-hours, can lead to productivity growth, and is inexpensive to manufacture.

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.

A valve drive for a cylinder head of an internal combustion engine has a camshaft which is rotatably mounted in a first and a second camshaft bearing and which includes at least one cam with a first cam curve and a second cam curve that differs from the first cam curve. A gas exchange valve can be actuated by the first or the second cam curve via a cam follower. A camshaft section is provided, by which the cam can be moved by an actuator such that the gas exchange valve can be actuated either via the first or the second cam curve via the cam follower. The camshaft and the cam have a fixed position relative to each other. The camshaft can be axially moved in the first and the second camshaft bearing. The camshaft bearings consist of a camshaft bearing block and a common bearing frame. A lubricant supply bore is provided which opens into a fourth lubricant groove in the bearing frame in order to supply the bearing points with lubricant. A first lubricant groove is provided in the first camshaft bearing block, and a second lubricant groove is provided in the second camshaft bearing block. These lubricant grooves correspond to the fourth lubricant groove and are open in the direction of the cam follower.

An engine camshaft has a lubricating oil passage formed along the longitudinal axis of the same, a cam communicating oil hole is radially formed from the lubricating oil passage to an outer peripheral surface of the camshaft at the same axial position as an engine valve. Cam lubrication holes are radially formed from the inside to cam surfaces of cam lobes formed around a cam carrier fitted around the camshaft. One of the cam lubrication holes of the cam lobes shifted to a position for operating the valve communicates with the cam communicating oil hole of the camshaft to supply lubricant oil.

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 backflow of oil to the engine's oil pump.

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.

The relates to an electromechanical camshaft adjuster comprising an electric motor and an adjusting gear, which has a housing two housing parts, that are sealed off with respect to each other by means of a static seal and with respect to the electric motor and a cylinder head by means of two dynamic seals. A first housing part of the adjusting gear a pot shape that tapers in a stepped manner towards a housing bottom of the housing part, said pot shape having three different inner diameter regions. In the region closest to the bottom with the smallest inner diameter, a stop plate that acts in the circumferential direction is held. In the region with the middle inner diameter, an output ring gear is mounted with play, and in the region with the largest inner diameter, an input ring gear is secured.

A valve drive for a cylinder head of an internal combustion engine has a camshaft which is rotatably mounted in a first and a second camshaft bearing and which includes at least one cam with a first cam curve and a second cam curve that differs from the first cam curve. A gas exchange valve can be actuated by the first or the second cam curve via a cam follower. A camshaft section is provided, by which the cam can be moved by an actuator such that the gas exchange valve can be actuated either via the first or the second cam curve via the cam follower. The camshaft and the cam have a fixed position relative to each other. The camshaft can be axially moved in the first and the second camshaft bearing. The camshaft bearings consist of a camshaft bearing block and a common bearing frame. A lubricant supply bore is provided which opens into a fourth lubricant groove in the bearing frame in order to supply the bearing points with lubricant. A first lubricant groove is provided in the first camshaft bearing block, and a second lubricant groove is provided in the second camshaft bearing block. These lubricant grooves correspond to the fourth lubricant groove and are open in the direction of the cam follower.