A continuously variable valve duration apparatus may include a camshaft, a plurality of first cams and second cams of which a cam key is formed respectively thereto, and of which relative phase angles with respect to the camshaft are variable, a plurality of rotation rings mounted to the camshaft and of which a ring key is formed thereto respectively, a plurality of inner brackets transmitting rotation of the camshaft to the cam keys of the first cams and the seconds respectively, a plurality of slider housings of which each inner bracket is rotatable inserted therein and of which a control slot is formed thereto respectively, an eccentric control shaft inserted into the control slots and a control portion selectively rotating the eccentric control shaft to move positions of the slider housing and change positions of the inner brackets.

A camshaft assembly is disclosed that comprises an inner shaft, an outer tube surrounding and rotatable relative to the inner shaft, and two groups of cam lobes mounted on the outer tube. The first group of cam lobes is fast in rotation with the outer tube and the second group is rotatably mounted on the outer surface of the outer tube and is connected for rotation with the inner shaft. A timing wheel is connected for rotation with the inner shaft to provide position information to a sensor, the timing wheel being formed as a separate part that is assembled to one of the cam lobes in the second group.

A variable valve gear for an internal combustion engine includes: a cam base portion integrally or separately provided in a camshaft, and immovably fixed to the camshaft; a cam lobe portion connected to the cam base portion so as to swing and shift between a first state where the cam lobe portion is positioned to project from an outer circumference of the base portion and a second state where the cam lobe portion is positioned to be lower than the cam base portion in the first state; a lock mechanism locking the cam lobe portion in the first and second state; and a biasing member biasing the cam lobe portion to be shifted to the first state, to such an extent that the cam lobe portion is shifted to the second state by reaction force from a cam follower when the locking mechanism is unlocked.

A rotational combustion engine that generates force from the reciprocal motion and centripetal motion of one or more pistons that is then converted into rotational motion of a first cam and second cam wherein the cams are separated by a 2-3 degree horizontal offset and an angle of 60 degrees as well as camshaft assembly and driving shaft to provide power to an entity such as an automobile.

A multiple variable valve lift apparatus may include a camshaft rotating by driving of an engine, a cam portion formed in a cylindrical shape having a hollow that the camshaft is inserted into, rotating together with the camshaft, configured to move along an axial direction of the camshaft, and forming a zero cam and a normal cam, a valve opening/closing device configured to be operated by at least one of the zero cam or the normal cam which are formed at the cam portion, an operating device disposed on an exterior circumference of the camshaft so as to move together with the cam portion, and a solenoid configured to selectively move the operating device along an axial direction of the camshaft, in which a journal, which has a radius being equal to a radius of the zero cam, is formed at the cam portion.

A camshaft for a multiple-cylinder internal combustion engine may include a sliding element comprising at least two cam elements, as well as a splined shaft that extends in an axial direction and on which the sliding element is received. The sliding element may comprise an internal spline system that interacts with an external spline system of the splined shaft such that the sliding element is seated fixedly on the splined shaft so as to rotate with the splined shaft. The sliding element may be received on the splined shaft such that the sliding element can, at least initially, be displaced axially. For axially-fixing the sliding element to the splined shaft, the sliding element may include a positively locking connection that is configured in the axial direction and is produced by way of at least one calked connection between the sliding element and the splined shaft. It should be understood that many camshafts include more than one sliding element.

A camshaft may include a shaft as well as a sliding element that is disposed on the shaft such that the sliding element is axially displaceable along a shaft axis. The shaft may comprise an external tooth for transmitting torque between the shaft and the sliding element. The external tooth may engage a mating tooth geometry formed in a passage of the sliding element. The sliding element on its axial end faces may comprise bearing collars that with the shaft form radial supporting bearings of the sliding element on the shaft. Further, the shaft may comprise cylindrical bearing portions for forming the radial supporting bearings, wherein the bearing portions can be configured with a diameter that is smaller than a diameter circumscribed by tips of the mating tooth geometry that protrude into the passage of the sliding element.

A valve train assembly includes a rocker arm assembly, and axial shifting cam assembly, and a lost motion device. The axial shifting cam assembly is movable between a first axial position and a second axial position on a camshaft, the cam assembly having a first cam having a first lobe, and a second cam having a second lobe. The first and second lobes are configured to each selectively engage the rocker arm assembly to respectively perform a first and a second discrete valve lift event. The lost motion device is operably associated with the rocker arm assembly and configured to perform a third discrete valve lift event, distinct from the first and second valve lift events.

A camshaft is equipped with an inner shaft which is arranged rotatably inside a cylindrical outer shaft. Further, in the inner shaft, a plurality of pin holes extend along diametrical directions thereof, and are disposed at intervals along the axial direction of the inner shaft. The directions in which adjacent pin holes extend are arranged at angles obtained by dividing 360 degrees by the number of cylinders. The inner shaft and the inner cams are fixed in a state in which large diameter portions of pins, each of which is provided with a small diameter portion and a large diameter portion, are press-fitted through insertion holes of the inner cams and notches of the outer shaft, and are press-fitted into the pin holes.

A composite profile evaluating method includes an adjusting step and a composite profile detecting step. In the adjusting step, a relative position between a fixed cam and a movable cam is adjusted. In the composite profile detecting step, at least either one of a first contact element, which is displaced along a diametrical direction of the fixed cam upon contacting a cam surface of the fixed cam, and a second contact element, which is displaced integrally with the first contact element and along a diametrical direction of the movable cam upon contacting a cam surface of the movable cam, is brought into contact with the cam surface of the fixed cam or the movable cam. In such a state, the composite profile is obtained by rotating the fixed cam and the movable cam, and detecting the amounts of displacement of the first and second contact elements.