Camshaft Gear/Sprocket: Description and Operation

NOTE:
^ For additional information on the C36 model not specifically listed below refer to AMG.
^ Numbers in parentheses ( ) indicate a component or tool in the associated illustration.

Function
When the engine is running, the camshaft adjuster rotates the inlet camshaft hydraulically/mechanically relative to the camshaft sprocket by 32°, to the "advanced" position and back to the "retarded" position.

The camshaft adjuster is actuated electro-mechanically by the fuel system control module. The positioning time of approximately 1 second is dependent on the engine oil pressure at the camshaft adjuster and on the oil viscosity and oil temperature, respectively. The position indicator on the camshaft sprocket (13) provides the camshaft rotational speed to the position sensor (9) as an input parameter for the control module.

Engine Switched Off (Retarded)
The compression spring (17) pushes the control plunger (18) against the circlip (19). The engine oil pressure in the camshaft adjuster is eliminated.

From 0 To 1000 --> 2000 RPM (Retarded)
The torque of the internally helically toothed camshaft sprocket (13) acting in the direction of rotation of the engine pushes the externally helically toothed positioning piston (14) against the cover (12) as a result of the screw action. Consequently, the likewise internally helically toothed positioning piston (14) holds the externally helically toothed flanged shaft (16) together with the bolted on camshaft (22) in the "retarded" position. The compression spring (17) pushes the control plunger (18) against the circlip (19). The engine oil flows through two oblique drillings in the camshaft flange and in the flanged shaft (16) into the working chamber (A) and holds the positioning piston (14) additionally in the "retarded" position with the available engine oil pressure. Leak oil flows off over control and positioning piston surface, through the control plunger drilling and 2 drillings (23) in the camshaft flange.





"Retarded" Position
- Servo magnet (Y49) not energized.
- Control plunger (18) against rear stop.
- Positioning piston (14) against front stop.
- Oil pressure in working chamber (A).


From 1000 To 2000 --> 5000 RPM (Advanced)
The control plunger (18) is pulled forward as far as the stop in the flanged shaft (16) by the servo magnet (Y49) against the force of the compression spring (17). The control plunger (18) closes the oil feed to the working chamber "A" and at the same time allows oil to flow to the working chamber "B" through 2 drillings each in the flanged shaft (16) and adjusting piston (14). The engine oil pressure moves the adjusting piston (14) as far as the stop on the flanged shah (16). As a result of the axial movement of the adjusting piston (14), the camshaft (22) bolted to the flanged shaft (16) is turned into the "advanced" position. The turning action is achieved as a result of the effect of the helical teeth on the camshaft sprocket (13), positioning piston (14) and flanged shaft (16). The engine oil in working chamber "A" flows off, assisted by the pushing action of the adjusting piston (14), over the flanged shaft (16) and through 2 drillings (23) in the camshaft flange.





"Advanced" Position
- Servo magnet (Y49) energized.
- Control plunger (18) against front stop.
- Positioning piston (14) against mar stop.
- Oil pressure in working chamber (B).

From 5000 RPM (Retarded)
The electro-magnetic actuator (Y49) is not energized and allows the control plunger to move. The compression spring (17) pushes the control plunger (18) against the circlip (19). The oil feed to the working chamber "B" is closed Off and oil is able to flow to working chamber "A" along 2 drillings in the flanged shaft (16). As a result of the engine oil pressure the control plunger (18) is moved as far as the cover (12).

This axial movement of the adjusting piston (14) rotates the camshaft (22) bolted to the flanged shaft (16) into the "retarded" position.

The rotational movement is a result of the screw affect of the helical teeth on the camshaft sprocket (13), positioning piston (14) and flanged shaft (16). The engine oil in the working chamber (B) flows off, assisted by the pushing action of the adjusting piston (14). through 2 drillings each in the adjusting piston (14), flanged shaft (16) and control plunger (18) through the control plunger (18) and 2 drillings in the camshaft flange (23).

Leak oil flows off over the control plunger and adjusting piston surfaces through the control plunger drilling and 2 drillings in the camshaft flange (23).

C36 Information





The adjustment range of the camshaft timing adjuster has been reduced by replacing the cover with a new version with a higher collar (lower arrow)
The Adjustment range is 26° Crank Angle (CKA)
The bolts (arrows) cannot be reused.