A valve timing control apparatus for an internal combustion engine includes a driving rotation member to which rotation of a crankshaft is transmitted, a driven rotation member coupled to a camshaft so as to be rotatable relative to the driving rotation member, an electric motor having a motor output shaft to cause rotation of the driven rotation member relative to the driving rotation member, a cover member arranged axially facing a front end portion of the motor output shaft and an electromagnetic induction type rotational angle detection mechanism disposed between the motor output shaft and the cover member so as to detect a rotational angle of the motor output shaft. The rotational angle detection mechanism has a detected part provided to the front end portion of the motor output shaft and a detecting part provided to a portion of the cover member axially facing the detected part.

A controller for controlling an internal combustion engine includes a valve timing adjuster, a variable valve lift mechanism and a processor. The processor controls a duty cycle of a drive signal in a selected one of control modes, thereby changing a relative rotational phase of a camshaft relative to an engine output shaft. The control modes include a specific control mode in which the duty cycle of the drive signal is adjusted to change a value of the current through a first motor. The processor performs, when changing the relative rotational phase through execution of the specific control mode, an abnormality diagnosis for the variable valve lift mechanism based on a comparison between the current value at the first motor and a reference current value. The processor sets the reference current value in accordance with a rotation angle of the output shaft of a second motor.

An internal combustion engine is provided with a plurality of cylinders, air intake valves provided to each of the cylinders, and a variable valve actuation mechanism for varying the valve actuation of the air intake valves. A motor drives the variable valve actuation mechanism. A motor controller controls the motor. The internal combustion engine is capable of operating in a cylinder deactivation mode, in which the air intake valves of some of the cylinders are kept shut. When the internal combustion engine is reactivated from the cylinder deactivation mode, the motor controller executes an air intake amount correction process, in which the opening duration of the air intake valves is temporarily increased, thereby increasing the amount of air taken in by operating cylinder for which the air intake valves have been opened or closed even during the cylinder deactivation mode.

An engine variable camshaft timing phaser (10) includes a sprocket (12), three ring gears (26, 28, 30), multiple planet gears (24), and a sun gear (22). The sprocket (12) receives rotational drive input from an engine crankshaft. One or more of the three ring gear(s) (26, 28, 30) receives rotational drive input from the sprocket (12) and rotates with the sprocket (12), and the remaining ring gear(s) (26, 28, 30) transmit rotational drive output to an engine camshaft (62). All three of the ring gears (26, 28, 30) engage with the planet gears (24). And the sun gear (22) also engages with the planet gears (24). In operation, relative rotational speeds between the sprocket (12) and the sun gear (22) causes the engine camshaft (62) to advance or retard engine valve opening and closing.

An electrically-actuated variable camshaft timing (VCT) phaser is employed for use with an internal combustion engine (ICE). The electrically-actuated VCT phaser includes a gear set assembly and a fixture. The gear set assembly has an input gear and an output gear, among other possible components. The input gear receives rotational drive input from an engine crankshaft, and the output gear transmits rotational drive output to an engine camshaft. The fixture is secured in the gear set assembly. Amid installation of the electrically-actuated VCT phaser on the ICE, the fixture constrains rotational movement of the gear set assembly. After installation, the fixture can be removed from the gear set assembly.

A valve timing adjusting device includes an intake variable valve mechanism and an exhaust variable valve mechanism. The exhaust variable valve mechanism includes an exhaust electric driving portion and an exhaust phase shifting portion including an input shaft. The exhaust phase shifting portion is disposed in a rotation transmission path between an exhaust camshaft and a crankshaft and configured to shift a rotation phase of the exhaust camshaft. The input shaft rotates in a rotational direction opposite to a rotational direction of the crankshaft when advancing the rotation phase. A phase of the exhaust phase shifting portion is configured to be shifted to a most advanced angle phase when the exhaust electric driving portion is de-energized or fails and when the exhaust phase shifting portion receives a torque in a forward rotational direction.

A two-stroke internal combustion engine has an engine block having a cylinder block and a cylinder head. The cylinder block defines a cylinder, an exhaust passage, and an exhaust valve passage. The engine also has a piston, an exhaust valve actuator operatively connected to at least one of the cylinder block and the cylinder head, and a reciprocating exhaust valve disposed at least in part in the exhaust valve passage. The exhaust valve has a shaft operatively connected to a valve actuator, and a blade connected to the shaft. A channel is defined along a face of the blade. The channel and a wall of the exhaust valve passage together define at least in part a valve passage. The valve passage permits flow of exhaust gas along the face of the blade. A width of the valve passage is at least a third of a width of the blade.

A drive-side rotor is rotated synchronously with a crankshaft. A driven-side rotor is rotated integrally with a camshaft. An internal gear section is formed at the driven-side rotor. An Oldham coupling includes: a driven Oldham flange that is formed at the drive-side rotor; a drive Oldham flange that is formed at the planetary rotor; and an Oldham intermediate that is configured to synchronize rotation of the driven Oldham flange and rotation of the drive Oldham flange while permitting eccentricity between the driven Oldham flange and the drive Oldham flange. There is satisfied a relationship of θ2<θ1 where: θ1 is a maximum tilt amount of the planetary rotor relative to the driven Oldham flange; and θ2 is a maximum tilt amount of the planetary rotor in a clearance formed at the Oldham coupling.

A harmonic drive includes an internally toothed housing element (2), a pot-shaped output element (4) which is mounted in the housing element (2), and a likewise pot-shaped, resilient drive element (19) which is connected to the output element (4) and has an external toothing system (13) which meshes with the internal toothing system (14) of the housing element (2). A spring element (35) is active between the housing element (2) and the output element (4), which spring element (35) is arranged in an annular chamber which is delimited radially to the inside by a sleeve section (24) of the resilient drive element (19), radially to the outside by a cylindrical section (5) of the output element (4), and in the axial direction firstly by an annular disc-shaped surface (23) of the housing element (2) and secondly by a bottom (9) of the output element (4).

A continuously variable valve duration apparatus includes a camshaft, a cam unit on which a cam is formed, a guide bracket including an upper guide boss, an internal wheel configured to transmit rotation of the camshaft to the cam unit, a wheel housing in which the internal wheel is rotatably inserted, wherein a guide thread is formed in a portion of the wheel housing, and of which a guide shaft is formed to be movably inserted into the upper guide boss, a worm wheel to which an internal thread engaging with the guide thread is formed in the worm wheel, and to which an external thread is formed thereon, a control shaft on which a control worm engaged with the external thread is formed, and an upper bushing mounted on a lower portion of the upper guide boss to support the guide shaft.