Methods and systems are provided for estimating engine oil temperature during conditions when sensors used for engine oil temperature measurement are not functional or not reliable. A null duty cycle of a solenoid spool valve of a variable cam timing mechanism is estimated. Then, a calibrated relationship between the duty cycle, an angular velocity of the associated cam, and the engine oil temperature is used to estimate an engine oil temperature when existing sensors used in the calculation of engine oil temperature calculation become unreliable.

A continuous variable valve duration apparatus may include first cam portion including first cam, of which relative phase angle of the first cam is variable, internal bracket transmitting rotation of the camshaft to the first cam portion, control shaft, of which a control gear is mounted thereto, slider housing in which the internal bracket is rotatably inserted, to be movable perpendicular to the camshaft and the slider housing on which a guide wall is formed, rocker shaft, first rocker arm rotatably disposed to the rocker shaft of which a first end portion contacts with the first cam and of which a second end portion is connected to a first valve, moving gear disposed within the guide wall, engaged with the control gear and the moving gear to move the slider housing according to rotation of the control shaft and a controller selectively rotating the control shaft.

A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Reducing engagement noise in a chain drive or belt drive for an internal combustion engine having a crankshaft having a driving sprocket and at least one shaft having a first driven sprocket and a second driven sprocket, where the driving sprocket and at least one of the first driven sprocket and the second driven sprocket contain a pattern of pitch radii such that the radial variation of the pitch radii excite tensions at non-prevalent orders in a drive system of the internal combustion engine. The non-prevalent engine cycle orders excited by each of the driving sprocket, the first driven sprocket and the second driven sprocket are different.

A differential includes a drive rotating body rotatable about a rotation axis, a planetary rotating body that is rotatable and is revolvable about the rotation axis, and a driven rotating body rotatable about the rotation axis. The planetary rotating body is made to mesh with each of the drive rotating body and the driven rotating body, so that a first speed reducer is constituted between the planetary rotating body and the drive rotating body and so that a second speed reducer is constituted between the planetary rotating body and the driven rotating body. The planetary rotating body is driven by an electric motor, and the drive rotating body is driven by a driving force from an engine. The intake camshaft is provided on the driven rotating body, and the exhaust camshaft is provided on the drive rotating body.

A camshaft phaser arrangement configured for a concentric camshaft assembly having an inner camshaft and an outer camshaft is provided. The camshaft phaser arrangement can facilitate independent phasing of intake and exhaust valves. The camshaft phaser arrangement includes a first driven wheel and a second driven wheel, both configured to be driven by a driving wheel. A first camshaft phaser is connected to the first driven wheel and configured to be connected to either the inner or outer camshaft. A second camshaft phaser is connected to the second driven wheel and configured to be connected to either the inner or outer camshaft which is not connected to the first driven wheel. A motion transfer assembly can connect the second camshaft phaser to the concentric camshaft assembly. One or both of the camshaft phasers can be an electric camshaft phaser or a hydraulic camshaft phaser.

Provided is a valve control apparatus for an engine that opens and closes an exhaust valve and intake value of the engine while rotating in conjunction with a crankshaft of the engine, the valve control apparatus including an exhaust valve opening and closing device opening and closing the exhaust valve during a first exhaust valve opening period and an intake valve opening and closing device opening and closing the intake valve during a first intake valve opening period.

A three valve cylinder head assembly includes a cylinder head mountable to an internal combustion engine. The cylinder head has a combustion chamber which has a sloped roof such that the combustion chamber has a wedge shape. Additionally, the cylinder head has an exhaust port and a pair of intake ports. An exhaust valve is movably integrated into the cylinder head for opening and closing the exhaust port. A pair of intake valves is each movably integrated into the cylinder head for opening and closing a respective one of the intake ports. A cam shaft is rotatably disposed on the cylinder head and the cam shaft engages the exhaust valve and each of the intake valves. The cam shaft sequentially opens the exhaust valve and each of the intake valves as the cam shaft rotates for supporting operation of the internal combustion engine.

A novel cylinder head arrangement for an in-line four cylinder or eight cylinder engine. A modified arrangement allows additional space for installation of wider rocker arm assemblies used for variable valve lift (VVL), cylinder deactivation (CDA) and other types of variable valve actuation (VVA). In one embodiment, cam towers adjacent the end two cylinders are not used. At least one end support is used, which may be an outboard bearing on a camshaft for each end. The wider rocker assemblies may then be installed. In another embodiment, cam towers adjacent the inner two cylinders are eliminated and a single camshaft support piece with a support bearing is installed between the inner cylinders to provide support for the camshafts. The wider rocker assemblies may then be installed on at least one of the middle cylinders. A novel oil control valve operates latches in switching rocker arm assemblies.

The present invention is capable of more smoothly changing a phase of a cam shaft in a rotation direction. A variable valve mechanism changes an opening/closing timing of an intake valve or an exhaust valve in response to an engine rotation speed. The variable valve mechanism includes: a cam sprocket which rotates in response to a rotation of a crank shaft; an intake cam shaft which is integrated with an intake cam and is provided to be rotatable relatively to the cam sprocket; and a link member that transmits a rotation from the cam sprocket to the intake cam shaft. The link member is supported by the cam sprocket to be swingable and swings in response to a change in rotation speed of the cam sprocket to rotate the intake cam shaft relatively to the cam sprocket.