An engine valve actuation system includes a rotatable camshaft, a first valve lifter, and a second valve lifter, structured to actuate valves in an engine in response to rotation of cams of the camshaft. The engine valve actuation system includes an anti-rotation device having a collar with a sleeve portion and a boss portion, and a bridge connector structured to couple with one of the valve lifters. Another one of the valve lifters is slidably received in the sleeve portion. The anti-rotation device reciprocates with the one of the valve lifters, and each of the valve lifters is restricted from rotation during service.

An engine valve actuation system includes a rotatable camshaft, a first valve lifter, and a second valve lifter, structured to actuate valves in an engine in response to rotation of cams of the camshaft. The engine valve actuation system includes an anti-rotation device having a collar with a sleeve portion and a boss portion, and a bridge connector structured to couple with one of the valve lifters. Another one of the valve lifters is slidably received in the sleeve portion. The anti-rotation device reciprocates with the one of the valve lifters, and each of the valve lifters is restricted from rotation during service.

A synchronous drive is provided in which a non-circular rotor generates a fluctuating corrective torque to counteract a fluctuating load torque on a driven rotor. The angular orientation of the non-circular rotor can vary relative to the driven rotor so as to change the phase angle of the fluctuating corrective torque relative to the driving rotor. The arrangement may be applied in internal combustion engines with variable valve timing (VVT) systems, wherein the phase angle of a fluctuating load torque presented on a cam rotor, due to forces arising from actuation of intake and/or exhaust valves by the camshaft, varies relative to the crankshaft. The phase angle of the fluctuating corrective torque is also varied relative to the crankshaft to maintain phase relationship with the fluctuating load torque and thereby maintain reduced cam torsional vibrations and span tensions provided by the non-circular rotor during operation.

A variable camshaft timing assembly that comprises a hub including at least one vane extending radially-outwardly away from a center axis; an elongated camshaft sleeve, configured to be received at least partially by an inner cavity of a camshaft, having a substantially annular outer surface including a distal bearing section, an end bearing section, and a hub section: the distal bearing section configured to be positioned radially-inwardly from and concentric with a distal bearing of the camshaft and to provide support to the distal bearing; the end bearing section, axially spaced from the distal bearing section, configured to be positioned radially-inwardly from and concentric with an end bearing of the camshaft and to provide support to the end bearing; and the hub section, configured to engage the hub, located axially between the distal bearing section and the end bearing section.

A method is disclosed for adaptively controlling an engine system of a motor vehicle comprising the steps of evaluating the outputs from angular position sensors associated with inlet and exhaust camshafts of an engine of the engine system to establish whether differences between the currently measured positions and previously saved positions are the result of elongation of an endless drive used to drive the camshafts or due to some other reason. If it is confirmed that the differences are due to elongation of the endless drive then the measured values of angular position are used in the control of a number of engine functions.

A cam-switching device switches between first and second cams provided so as to correspond to intake exhaust valves of an engine. In a case of switching from the first cam to the second cam, a cylinder resting unit stops the opening and closing operations of the intake and exhaust valves in the same combustion cycle, and a cam shaft moving unit starts sliding the cam shaft in a first cam angle range. In a case of switching from the second cam to the first cam, the cylinder resting unit stops the opening and closing operations of the intake and exhaust valves in the same combustion cycle, and the cam shaft moving unit starts sliding the cam shaft in a second cam angle range.

A synchronous drive is provided in which a non-circular rotor generates a fluctuating corrective torque to counteract a fluctuating load torque on a driven rotor. The angular orientation of the non-circular rotor can vary relative to the driven rotor so as to change the phase angle of the fluctuating corrective torque relative to the driving rotor. The arrangement may be applied in internal combustion engines with variable valve timing (VVT) systems, wherein the phase angle of a fluctuating load torque presented on a cam rotor, due to forces arising from actuation of intake and/or exhaust valves by the camshaft, varies relative to the crankshaft. The phase angle of the fluctuating corrective torque is also varied relative to the crankshaft to maintain phase relationship with the fluctuating load torque and thereby maintain reduced cam torsional vibrations and span tensions provided by the non-circular rotor during operation

A variable camshaft timing assembly that comprises a hub including at least one vane extending radially-outwardly away from a center axis; an elongated camshaft sleeve, configured to be received at least partially by an inner cavity of a camshaft, having a substantially annular outer surface including a distal bearing section, an end bearing section, and a hub section: the distal bearing section configured to be positioned radially-inwardly from and concentric with a distal bearing of the camshaft and to provide support to the distal bearing; the end bearing section, axially spaced from the distal bearing section, configured to be positioned radially-inwardly from and concentric with an end bearing of the camshaft and to provide support to the end bearing; and the hub section, configured to engage the hub, located axially between the distal bearing section and the end bearing section.

A control device includes an engine valve and a variable valve actuation mechanism that is able to change at least one of a valve operating angle and valve lift of the engine valve. When the at least one of the valve operating angle and the valve lift is larger than or equal to a prescribed upper limit, the control device increases an operating speed of the variable valve actuation mechanism as compared with when the at least one of the valve operating angle and the valve lift is smaller than the prescribed upper limit.

A cam-switching device switches between first and second cams provided so as to correspond to intake exhaust valves of an engine. In a case of switching from the first cam to the second cam, a cylinder resting unit stops the opening and closing operations of the intake and exhaust valves in the same combustion cycle, and a cam shaft moving unit starts sliding the cam shaft in a first cam angle range. In a case of switching from the second cam to the first cam, the cylinder resting unit stops the opening and closing operations of the intake and exhaust valves in the same combustion cycle, and the cam shaft moving unit starts sliding the cam shaft in a second cam angle range.