Systems and methods for operating an engine with deactivating valves are presented. In one example, a groove in a camshaft controls oil flow to a valve operator that selectively activates and deactivates a poppet valve of a cylinder. The groove moves with the camshaft so that oil delivery to the valve operator is timed properly to deactivate and reactivate the cylinder.

A continuous variable valve duration apparatus includes a camshaft, a first and second cam portion, each including a cam and a cam key, where the camshaft is inserted into the first and second cam portions and where relative phase angles with respect to the camshaft are variable, a first and second inner bracket transmitting a rotation of the camshaft to the first and second cam portions respectively, a first and second slider housing, a cam cap rotatably supporting the first and second cam portions respectively, a slider pin rotatably inserted into the first sliding hole and slidably inserted into the camshaft, a cam pin on which a cam key slot for the cam key to be slidably inserted thereinto is formed, a control shaft disposed parallel to the camshaft and engaged with the first and second slider housings, and a control portion selectively rotating the control shaft.

A continuous variable valve duration apparatus may include a camshaft, a cam device, of which the camshaft is inserted thereto, of which a phase angle with respect to the camshaft is variable, and the cam device on which a cam key is formed, an inside bracket transmitting rotation of the camshaft to the cam device and on which a first slide opening and a second sliding opening are formed respectively, a slider housing in which the inside bracket is rotatably inserted and of which relative position with respect to the camshaft is variable, a controller selectively changing the relative position of the slider housing, a cam pin of which a cam key opening for the cam key to be slidably inserted thereto is formed and slidably inserted into the second sliding opening and a slider pin rotatably inserted into the first sliding opening and slidably inserted into the camshaft.

In a valve train of an internal combustion engine, an input sprocket mounting portion is provided on one end of an exhaust camshaft, and a valve operating cam portion is formed on the other end of the camshaft. A decompression shaft of a decompression device is inserted in a decompression shaft hole, which is formed from the input sprocket mounting portion toward the valve operating cam portion. The decompression shaft hole is formed at a position offset from an axis of the camshaft. A camshaft inner oil passage is formed in the camshaft to extend from one end toward the other end of the camshaft in parallel arrangement to the decompression shaft hole to supply lubricant from the bearing journal portion to the bearing journal portion. The above arrangement makes it possible to supply a sufficient amount of lubricant oil to slide portions of the valve train of a saddle riding vehicle.

An oil supply path passes through members separate from a cylinder head (4) to supply a lubricant to bearings (73, 74) of camshaft journals. The oil supply path includes an oil supply passage (66) for the camshaft above the camshaft (19, 20), a connection passage (64) for the camshaft between the oil supply passage for the camshaft and an internal passage (61, 62) in the cylinder head (4), and branch oil passages (68) for the camshaft journals. Each branch oil passage branches off from the oil supply passage for the camshaft, and is connected to one of the bearings (73, 74) from above. Each of the branch passages includes a throttle (168) with a smaller cross-sectional flow area than the oil supply passage for the camshaft.

An internal combustion engine includes at least one cylinder crankcase, at least one cylinder head (1), at least one overhead camshaft (2), at least two rocker arms (3) which are driven by the camshaft (2) and actuate the combustion valves, the camshaft(s) (2) being mounted in the cylinder head housing, and an oil supply line (9) which is situated in particular in the area of the top face of the cylinder head (1) for lubricating camshaft bearing brackets (10) and the rocker arm brackets (11).

A cam cap is placed on a journal of a camshaft attached to a sprocket to constitute a bearing supporting the journal. The cam cap includes an accommodating groove in which a thrust plate provided on the journal is accommodated, an oil passage having an opening at a position facing a camshaft oil groove of the journal, the oil passage communicating with the accommodating groove, and an oil reservoir provided in a first sidewall of the accommodating groove. The cam cap is placed on the journal such that the accommodating groove is located at a position closer to the sprocket than is the opening of the oil passage. When the thrust plate is accommodated in the accommodating groove, the oil passage and the oil reservoir communicate with each other at a position outward of an outer peripheral edge of the thrust plate in a radial direction of the thrust plate.

A oil supply structure of an internal combustion engine, includes: an oil flowing path which is formed to extend along a camshaft vertically above at least one of intake and exhaust camshafts (3a, 3b) of the internal combustion engine, and in which oil flows; an oil supply portion provided on one end side of the oil flowing path, and supplying oil to the oil flowing path; and oil ejection holes aligned along the oil flowing path, provided to be opened vertically downward, and through which the oil of the oil flowing path is ejected toward the camshaft, wherein, in the oil flowing path, a partitioning portion, which extends along the oil ejection holes toward the other end side opposite to the oil supply portion from one end side, and partitions the inside of the oil flowing path, is provided.

A cam carrier assembly includes a body made of a material lighter than aluminum. The body has a first side operably coupled with a cylinder head and a second side having bearing surfaces with bearing inserts. The bearing inserts support the camshaft. A series of apertures extend between the first and second sides of the body. Lobes of the camshaft operably couple with the valves of the cylinder head through the series of apertures extending between the first and second sides of the body.

Methods and systems are provided for regulating oil flow to advance and retard chambers of a variable cam timing (VCT) system and to a thrust bearing of a camshaft via an oil control valve. In one example, an oil control valve may be housed within a cam journal cap the cam journal cap comprising a thrust bearing for receiving and retaining a camshaft. The cam journal cap may include a vertical bore configured to house the control valve, where the vertical bore may include a first port for receiving oil from an oil pump, a second port for flowing oil to an advance chamber of a VCT system, a third port for flowing oil to a retard chamber of the VCT system, a fourth port, coupled to the thrust bearing for flowing oil thereto, and a drain port for flowing oil to an oil sump.