A camshaft adjusting system (1) is provided for a first camshaft (2) and a second camshaft (3) which are arranged concentrically with respect to one another, the second camshaft being arranged inside the first camshaft. A hydraulic camshaft adjuster (4) of the vane-cell type is set up for the adjustment of the first camshaft, and an electric camshaft adjuster (5) is set up for the adjustment of the second camshaft. A rotor contact flange (17) of an output ring (6) of the electric camshaft adjuster is arranged radially inside a first cover (23) of the hydraulic adjuster, the output ring which is equipped for the transmission of torque to the second camshaft is arranged at least partially radially and axially inside a rotor (7) of the hydraulic camshaft adjuster. A camshaft adjusting unit is also provided having a camshaft adjusting system of this type and two camshafts.

A camshaft adjusting system (1) is provided for a first camshaft (2) and a second camshaft (3) which are arranged concentrically with respect to one another, the second camshaft being arranged inside the first camshaft. A hydraulic camshaft adjuster (4) of the vane-cell type is set up for the adjustment of the first camshaft, and an electric camshaft adjuster (5) is set up for the adjustment of the second camshaft. A rotor contact flange (17) of an output ring (6) of the electric camshaft adjuster is arranged radially inside a first cover (23) of the hydraulic adjuster, the output ring which is equipped for the transmission of torque to the second camshaft is arranged at least partially radially and axially inside a rotor (7) of the hydraulic camshaft adjuster. A camshaft adjusting unit is also provided having a camshaft adjusting system of this type and two camshafts.

A valve bridge system comprises a valve bridge configured to extend between at least two engine valves of an internal combustion engine. In one embodiment, a valve bridge guide is operatively connected to the valve bridge and configured to extend between at least two valve springs respectively corresponding to the at least two engine valves, the valve bridge guide defining a surface conforming to a valve spring of the at least two valve springs. In another embodiment, the valve bridge guide may comprise at least a first member maintained in a first fixed position relative to and at a predetermined distance from the valve bridge. In both embodiments, the valve bridge guide is configured to avoid contact with the valve bridge in a controlled state, but to permit contact with valve bridge to resist uncontrolled movement of the valve bridge.

A valve bridge system comprises a valve bridge configured to extend between at least two engine valves of an internal combustion engine. In one embodiment, a valve bridge guide is operatively connected to the valve bridge and configured to extend between at least two valve springs respectively corresponding to the at least two engine valves, the valve bridge guide defining a surface conforming to a valve spring of the at least two valve springs. In another embodiment, the valve bridge guide may comprise at least a first member maintained in a first fixed position relative to and at a predetermined distance from the valve bridge. In both embodiments, the valve bridge guide is configured to avoid contact with the valve bridge in a controlled state, but to permit contact with valve bridge to resist uncontrolled movement of the valve bridge.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

A valve train for an internal combustion engine may include a cam shaft and a cam follower. The valve train may also include a first cam arranged on the cam shaft for conjoined rotation. The valve train may further include a second cam arranged on the cam shaft for conjoined rotation and axially adjacent to the first cam. The cam follower may be axially adjustable between a first position, in which the cam follower is drive-connected to the first cam, and a second position, in which the cam follower is drive-connected to the second cam. The cam follower may include a mechanical adjustment device interacting with the cam shaft for axially adjusting the cam follower between the first position and the second position.

A valve train for an internal combustion engine may include a cam shaft and a cam follower. The valve train may also include a first cam arranged on the cam shaft for conjoined rotation, and a second cam for conjoined rotation, arranged on the cam shaft axially adjacent to the first cam. The cam follower may be axially adjustable between a first position, in which the cam follower is drive-connected to the first cam, and a second position, in which the cam follower is drive-connected to the second cam. The cam follower may also include a mechanical adjustment device interacting with the cam shaft for axially adjusting the cam follower between the first position and the second position.

A valve train for an internal combustion engine may include a cam shaft and a cam follower. The valve train may also include a first cam arranged on the cam shaft for conjoined rotation, and a second cam for conjoined rotation, arranged on the cam shaft axially adjacent to the first cam. The cam follower may be axially adjustable between a first position, in which the cam follower is drive-connected to the first cam, and a second position, in which the cam follower is drive-connected to the second cam. The cam follower may also include a mechanical adjustment device interacting with the cam shaft for axially adjusting the cam follower between the first position and the second position.

A camshaft adjusting system (1) is provided for a first camshaft (2) and a second camshaft (3) which are arranged concentrically with respect to one another, the second camshaft (3) being arranged within the first camshaft (2). A vane-cell type hydraulic camshaft adjuster (4) is configured for adjusting the first camshaft (2) and an electric camshaft adjuster (5) is configured for adjusting the second camshaft (3). A front cover (7) which is fastened to a stator (6) of the hydraulic camshaft adjuster (4) and which closes off the camshaft adjuster (4) at a side facing away from the camshaft has an internal toothing (8) for supporting a flex pot (9) which is attached to the second camshaft (3) and which is designed for receiving torque from the electric camshaft adjuster (5). A camshaft adjusting unit having the camshaft adjusting system (1) and two camshafts (2, 3) is also provided.