A valve gear includes a camshaft, a first cam and a second cam that drive an intake valve or an exhaust valve, and a synchronous cam that rotates in synchronism with the first and second cams. The valve gear includes a rocker shaft, a rocker arm, and a cam follower swingably supported by the rocker shaft and that comes into contact with the synchronous cam. The valve gear includes a thruster that converts the swinging motion of the cam follower into a thrust and moves the rocker arm to a first side or a second side in the axial direction. The valve gear makes the camshaft compact, and also increases the reliability of operation at high rotations and reduces an operation sound at low rotations.

A valve gear includes a camshaft, a first cam and a second cam that drive an intake valve or an exhaust valve, and a synchronous cam that rotates in synchronism with the first and second cams. The valve gear includes a rocker shaft, a rocker arm, and a cam follower swingably supported by the rocker shaft and that comes into contact with the synchronous cam. The valve gear includes a thruster that converts the swinging motion of the cam follower into a thrust and moves the rocker arm to a first side or a second side in the axial direction. The valve gear makes the camshaft compact, and also increases the reliability of operation at high rotations and reduces an operation sound at low rotations.

A lost motion mechanism can comprise a castellation device, comprising a casing, an upper castellation, and a lower castellation. The casing can comprise a first linear slot and a second linear slot perpendicular to the first linear slot. Upper castellation can comprise an upper body, spaced upper teeth extending from the upper body, the spaced upper teeth forming spaced upper gaps therebetween, and an actuation peg extending from the upper body into the first linear slot. Lower castellation can comprise a lower body, spaced lower teeth extending from the lower body, the spaced lower teeth forming spaced lower gaps therebetween, and an anti-rotation peg extending from the lower body into the second linear slot. An actuator can be configured with the lost motion mechanism so that a movable arm comprises a forked end configured to move on the actuation peg as the movable arm swivels.

A camshaft for an internal combustion engine, with a drivable basic shaft and a cam piece which is mounted in the basic shaft, wherein the basic shaft passes through a passage in the cam piece, and the cam piece is mounted in the basic shaft in a rotationally fixed and axially displaceable manner. In the case of such a camshaft, it is provided that the basic shaft has a polygonal profile, and the passage in the cam piece has a complementary polygonal profile for receiving the basic shaft. The camshaft is preferably used in a motorcycle which has an internal combustion engine with two cylinders.

A continuous variable valve duration apparatus may include a camshaft, a plurality of wheels mounted to the camshaft, of which a wheel key is formed thereto respectively, a plurality of cam portions of which a cam and a cam key are formed thereto respectively, of which the camshaft is inserted thereto, of which relative phase angle with respect to the camshaft is variable, a plurality of inner brackets connected with the each wheel key and the each cam key, a plurality of slider housings of which the each inner bracket is rotatably inserted thereto, and movable up and down direction of an engine, a control portion selectively moving the slider housings to adjust relative position of a rotation center of the inner brackets and a guider guiding movement of the sliding housings.

A continuously variable valve lift apparatus may include a camshaft, a cam portion on which a cam is formed and to which the camshaft is inserted, a slider housing to which the cam portion is rotatably inserted and is movable with respect to the camshaft, a control portion selectively changing the position of the slider housing, an output portion rotatable around a pivot shaft and to which a valve shoe is formed. The valve shoe drives a valve unit.

A variable valve mechanism includes a variable arm including a first arm and a second arm. The second arm is pivotally supported so as to be swingable by a support shaft. A position of the support shaft is a position where, during a base circle phase, in side view, a second segment connecting an axis of a roller to an axis of the support shaft is longer than a first segment connecting the axis of the roller to an axis of a camshaft, and an angle of the second segment formed with respect to a third segment connecting the axis of the roller to a swing axis of a roller arm is 60° to 120° toward the camshaft. The second arm extends from the support shaft such that a distal end portion of the second arm protrudes in between a cam and the roller.

A sliding camshaft is provided which may include a base shaft, an over-molded trigger wheel, and a distal axially movable structure. The distal axially movable structure may further include a distal journal in addition to at least one standard journal and lobe packs. A control groove is defined in the distal axially movable structure. The over-molded trigger wheel is mounted on the distal axially movable structure. The over-molded trigger wheel is operatively configured to move between at least a first position and a second position together with the distal axially movable structure via engagement between the control groove and an actuator. The over-molded trigger wheel may be press fitted on distal axially movable structure and is adapted to accurately communicate with a sensor regardless of the position of the distal axially movable structure.

A novel latch seat for a switching rocker arm assembly used in variable valve actuation (VVA) systems for internal combustion engines. The seat is formed interactively in the assembled switching rocker arm using a novel fixture and press. The press interactively creates a curved dimple of the correct curvature, position and depth while measuring several lash dimensions. Since the latch seat is formed on the assembled rocker arm assembly, the latch seat depth is designed to account for the inaccuracies in the rocker arm assembly parts which create lash. Therefore all of the parts may be made with less precision since the latch seat is sized to compensate for the inaccuracies of all of the parts. The rocker arm assembly parts now may be manufactured to less stringent standards, but result in a rocker arm assembly with same accuracy of rocker arm assemblies manufactured to previous standards.

A rocker arm assembly constructed in accordance to one example of the present disclosure includes an outer rocker arm and an inner rocker arm. The outer rocker arm has a first roller configuration that rotates around a first axis. The inner rocker arm has a second roller configuration that rotates around a second axis. The inner rocker arm is configured to move between a latched and unlatched position relative to the outer rocker arm. One of the first and second axes is positioned for alignment over an engine valve. The other of the first and second axes is offset from the engine valve.