An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode includes: a rocker shaft that defines a pressurized oil supply conduit; a rocker arm that receives the rocker shaft and rotates around the rocker shaft, the rocker arm including a rocker arm oil supply passage defined in the rocker arm; a valve bridge for engaging a first exhaust valve and a second exhaust valve; a hydraulic lash adjuster assembly, disposed on the rocker arm, including a first plunger body movable between a first position and a second position; and a check valve, disposed on the rocker arm, including an actuator for selectively releasing pressure in the hydraulic lash adjuster assembly. In the engine braking mode, by rotation of the rocker arm the pressurized oil supply conduit is brought into fluid communication with the rocker arm oil supply passage.

Even in the case where, due to distortion (undulation) or the like of an end surface of an adjusting screw abutting on a valve stem end, there exists a non-linear undulation movement amount in a movement amount of the end surface with respect to a rotation return angle of the adjusting screw, the undulation movement amount is continuously measured, and a screw return movement amount based on a screw pitch and on the rotation return angle is continuously calculated, and, when a total movement amount of the undulation movement amount and the screw return movement amount has attained a prescribed clearance, return rotation is ended.

Even in the case where, due to distortion (undulation) or the like of an end surface of an adjusting screw abutting on a valve stem end, there exists a non-linear undulation movement amount in a movement amount of the end surface with respect to a rotation return angle of the adjusting screw, the undulation movement amount is continuously measured, and a screw return movement amount based on a screw pitch and on the rotation return angle is continuously calculated, and, when a total movement amount of the undulation movement amount and the screw return movement amount has attained a prescribed clearance, return rotation is ended.

A fuel injection pump includes a cam rotating with a camshaft, a tappet reciprocating in response to rotation of the cam, a cylinder, a plunger, and a thrust washer. The thrust washer is located between the cam and a casing housing the camshaft at both ends of the cam in an axial direction of the cam. The tappet includes a tappet body, a roller, a supporting member, and a contact surface formed at an outer peripheral part of the tappet. The thrust washer includes a rotation restricting part that protrudes toward the tappet over a maximum lift position. The rotation restricting part restricts rotation of the tappet relative to a center axis of the tappet body by being contact with the contact surface.

A fuel injection pump includes a cam rotating with a camshaft, a tappet reciprocating in response to rotation of the cam, a cylinder, a plunger, and a thrust washer. The thrust washer is located between the cam and a casing housing the camshaft at both ends of the cam in an axial direction of the cam. The tappet includes a tappet body, a roller, a supporting member, and a contact surface formed at an outer peripheral part of the tappet. The thrust washer includes a rotation restricting part that protrudes toward the tappet over a maximum lift position. The rotation restricting part restricts rotation of the tappet relative to a center axis of the tappet body by being contact with the contact surface.

A fuel injection pump includes a cam rotating with a camshaft, a tappet reciprocating in response to rotation of the cam, a cylinder, a plunger, and a thrust washer. The thrust washer is located between the cam and a casing housing the camshaft at both ends of the cam in an axial direction of the cam. The tappet includes a tappet body, a roller, a supporting member, and a contact surface formed at an outer peripheral part of the tappet. The thrust washer includes a rotation restricting part that protrudes toward the tappet over a maximum lift position. The rotation restricting part restricts rotation of the tappet relative to a center axis of the tappet body by being contact with the contact surface.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode includes: a rocker shaft that defines a pressurized oil supply conduit; a rocker arm that receives the rocker shaft and rotates around the rocker shaft, the rocker arm including a rocker arm oil supply passage defined in the rocker arm; a valve bridge for engaging a first exhaust valve and a second exhaust valve; a hydraulic lash adjuster assembly, disposed on the rocker arm, including a first plunger body movable between a first position and a second position; and a check valve, disposed on the rocker arm, including an actuator for selectively releasing pressure in the hydraulic lash adjuster assembly. In the engine braking mode, by rotation of the rocker arm the pressurized oil supply conduit is brought into fluid communication with the rocker arm oil supply passage.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode includes: a rocker shaft that defines a pressurized oil supply conduit; a rocker arm that receives the rocker shaft and rotates around the rocker shaft, the rocker arm including a rocker arm oil supply passage defined in the rocker arm; a valve bridge for engaging a first exhaust valve and a second exhaust valve; a hydraulic lash adjuster assembly, disposed on the rocker arm, including a first plunger body movable between a first position and a second position; and a check valve, disposed on the rocker arm, including an actuator for selectively releasing pressure in the hydraulic lash adjuster assembly. In the engine braking mode, by rotation of the rocker arm the pressurized oil supply conduit is brought into fluid communication with the rocker arm oil supply passage.

A cam treatment to reduce the friction coefficient thereof relative to a counterpart in an area provided with a hard coating made from amorphous Diamond-Like Carbon or DLC, involves disposing the cams on a support, bringing the support and the cams into a chamber placed under vacuum so as to clean the cams, bringing the support into relative movement along a trajectory of travel relative to a coating source, and taking the cams off the support before assembling them on a camshaft; the method involves disposing the cams on the support in a fixed configuration which is defined in such a way that the cams are brought successively opposite the source with orientations and at distances substantially identical relative to the source, to deposit a hard coating made from amorphous Diamond-Like Carbon or DLC, selectively on the fraction of the section of the cams that is oriented towards the source.

A cam treatment to reduce the friction coefficient thereof relative to a counterpart in an area provided with a hard coating made from amorphous Diamond-Like Carbon or DLC, involves disposing the cams on a support, bringing the support and the cams into a chamber placed under vacuum so as to clean the cams, bringing the support into relative movement along a trajectory of travel relative to a coating source, and taking the cams off the support before assembling them on a camshaft; the method involves disposing the cams on the support in a fixed configuration which is defined in such a way that the cams are brought successively opposite the source with orientations and at distances substantially identical relative to the source, to deposit a hard coating made from amorphous Diamond-Like Carbon or DLC, selectively on the fraction of the section of the cams that is oriented towards the source.