Rocker arm assembly for engine braking

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode, the exhaust valve rocker arm assembly comprising:

• a rocker shaft that defines a pressurized oil supply conduit;
• a rocker arm configured to receive the rocker shaft and configured to rotate around the rocker shaft, the rocker arm including a rocker arm oil supply passage defined therein;
• a valve bridge configured to engage a first exhaust valve at a spherical elephant foot and a second exhaust valve at a cylindrical elephant foot;
• a hydraulic lash adjuster assembly disposed on the rocker arm and including a first plunger body movable between a first position and a second position, wherein in the first position, the first plunger body extends rigidly for cooperative engagement with the valve bridge, the hydraulic lash adjuster assembly including an actuator configured to selectively release pressure in the hydraulic lash adjuster assembly;
• and
• a pressure relief valve assembly disposed on the rocker arm and configured to selectively release oil from the hydraulic lash adjuster assembly,
• wherein, in the engine braking mode, pressurized oil is communicated through the pressurized oil supply conduit, through the rocker arm oil supply passage, and against the actuator, such that the first plunger body occupies the first position and acts on the valve bridge during rotation of the rocker arm to a first angle, opening the first exhaust valve a predetermined distance while the second exhaust valve remains closed.