A camshaft adjuster, comprising a drive element and an output element, wherein the drive element can be rotated in relation to the output element within an angular range between an early and a late position. The camshaft adjuster also includes a spring configured to brace the drive element with the output element, wherein the spring is configured to rotate the drive element in relation to the output element into a desired position within the angular range and is further configured to angularly adjust from both an early position and a late position into a direction of the desired position.

A camshaft housing includes two longitudinal frame bars and lateral frame bars. The longitudinal frame bars extend in the axial direction of a camshaft. The lateral frame bars extend between the longitudinal frame bars. A bearing portion is arranged in each of the lateral frame bars to rotationally support the camshaft. Each lateral frame bar has a bolt hole to receive a bolt that is inserted through the bolt hole to fix the camshaft housing to a cylinder head body. The bolt hole extends through the lateral frame bar and is arranged on the outer side of the bearing portion in the longitudinal direction of the lateral frame bar. Each longitudinal frame bar has a vibration reducing portion. The cross-sectional area of the longitudinal frame bar gradually changes in the longitudinal direction of the longitudinal frame bar.

An internal combustion engine valve timing control device includes a communication passage formed in a first rotating member to communicate with a working chamber, and including a first opening. The first opening is opened to a back pressure chamber when a tip portion of a lock member is inserted in a lock hole, and is closed by the lock member when the tip portion of the lock member is out of the lock hole. A first cross-sectional area is smaller than a second cross-sectional area, wherein the first cross-sectional area is a smaller one of a minimum cross-sectional area of the communication passage and an open cross-sectional area of the first opening, and the second cross-sectional area is a smaller one of a minimum cross-sectional area of an exhaust passage and an open cross-sectional area of an opening of the exhaust passage opened to the back pressure chamber.

A valve operating system for a multicylinder engine opens and closes a pair of valves provided on each of cylinders by means of a pair of rocker arms operated by a cam provided on a camshaft supported on a cam holder. When viewed in a direction of a cylinder axis, the pair of rocker arms of at least one of the cylinders are inclined in opposite directions to each other with respect to a direction orthogonal to a camshaft axis. Therefore, thrust loads acting on the camshaft from the pair of rocker arms are counteracted individually for each of the cylinders, thereby enabling the thrust load to be reduced and axial movement of the camshaft to be prevented.

A variable valve lift (VVL) system for an internal combustion engine is provided that utilizes hydraulic fluid supply pressure feedback to provide noise free operation. The VVL system includes a high pressure pump, a solenoid valve, a pressure translating device, a one-way valve, and a hydraulic fluid pressure sensor. The high pressure pump is fluidly connected to the solenoid valve and pressure translating device by at least one fluid gallery that forms a high pressure chamber. The solenoid valve selectively fluidly connects the high pressure chamber to a middle pressure chamber formed by at least one fluid gallery that fluidly connects the one-way valve to the solenoid valve. The hydraulic fluid pressure sensor is arranged to detect a hydraulic fluid supply pressure of the one-way valve and provides feedback to an electronic controller that determines a proper fluid intake opening timing of the solenoid valve.

A planetary gear assembly (30) and method of assembly in an electric camshaft phaser (20) with a split ring gear including a drive-side ring gear portion (32) rotatable by an engine crankshaft and an output-side ring gear portion (34) that can be connected to a camshaft (22). A plurality of rotatable planetary gears (36a, 36b, 36c) can be interposed between the split ring gear and the sun gear (28). The output-side ring gear portion (34) can have a different number of teeth than the drive-side ring gear portion (32) by a value corresponding to a multiple of the number of planetary gears (36a, 36b, 36c). A compliant planetary gear carrier (40, 140) can support the plurality of planetary gears (36a, 36b, 36c) allowing variance of a normally equidistant distance between separate spaced rotational axes of at least two of the planetary gears (36a, 36b, 36c) to selectively compensate for mechanical tolerances of the drive-side ring gear portion (32) and the output-side ring gear portion (34) of the split ring gear.

A driving rotor is rotational about a rotational shaft center in conjunction with a crankshaft. A driven rotor is rotational about the rotational shaft center in conjunction with the camshaft. A deceleration mechanism is configured to change a relative rotational phase between the driving rotor and the driven rotor by using a driving force of an electric motor. The deceleration mechanism includes an internal gear portion, which includes an internal tooth formed inward in a radial direction, and an external gear portion, which includes an external tooth formed outward in a radial direction and engages with the internal tooth. A linear expansion coefficient of the external gear portion is larger than a linear expansion coefficient of the internal gear portion.

A variable valve drive of an internal combustion engine is provided that includes at least one gas exchange valve, the valve stroke of said gas exchange valve predefined by cams of a camshaft, and by at least one switchable rocker arm. The switchable rocker arm, having a first lever and a second lever, selectively transmits cam lift to the gas exchange valve. The second lever is selectively coupled to the first lever by a coupling. The coupling is activatable by an elongated activation arm on which one leaf spring is disposed for the coupling of the switchable rocker arm. The elongated activation arm is longitudinally displaceable from a locking position to an unlocking position by a linear actuator. A damper mass is disposed or configured to be capable of oscillating on the elongated activation arm and/or on the leaf spring of the elongated activation arm.

A valve lifter with a variable lift mechanism is required to be deployed at a predetermined angle with respect to a cam unit, and the present invention is intended to achieve this requirement with a simple configuration without too much processing such as a fitting of the conventional longitudinal groove and a pin. A cam sliding contact surface of a valve lifter on which a high lift cam and a low lift cam slides is formed to be a smooth inclined surface and a cam slide starting point is lower than a cam slide terminating point, thereby establishing an elevation difference between the cam slide starting point and the cam slide terminating point. As a result, since the high lift cam and the low lift cam always move uphill on the cam sliding contact surface, namely, from the low cam slide starting point toward the high cam terminating point along the slope of the cam sliding contact surface, the valve lifter is not subjected to a force around the reciprocating axis from the cam and therefore, the direction of the valve lifter is maintained constant.

A valve opening and closing timing control apparatus includes: a driving side rotator disposed rotatably about a rotation axis and configured to rotate synchronously with a crankshaft of an internal combustion engine; a driven side rotator disposed rotatably about the rotation axis and configured to be rotatable relative to the driving side rotator and to rotate integrally with a valve opening and closing camshaft of the internal combustion engine; and a phase adjustment mechanism configured to set a relative rotation phase between the driving side rotator and the driven side rotator by a driving force of an electric actuator. The phase adjustment mechanism includes: an internally toothed ring gear; an inner gear; and a drive shaft, and the valve opening and closing timing control apparatus further includes: a biasing member; and a displacement regulation portion.