Crankcase ventilation system

摘要

A crankcase ventilation system for a vehicle includes an arrangement of flow conduits and control valves which cooperate with a two-chamber accumulator and with various vehicle components to route crankcase gases to the intake manifold. The primary vehicle components include a compressor, an aftercooler positioned downstream from the compressor, and an engine having an intake manifold and a crankcase. One chamber of the accumulator is coupled by one conduit to the inlet side of the compressor and by a second conduit to the outlet side of the compressor. These two conduits are controlled by a dual valve arrangement. The other chamber of the accumulator is connected by one conduit to the crankcase and by a separate conduit to the intake manifold. Each conduit includes a control valve. The system operates on pressure differences existing between these various components. The cycle begins by opening the conduit which is connected to the inlet side of the compressor. This creates a low pressure on that side of the diaphragm. Due to their higher pressure, the crankcase gases empty into the accumulator and when a predetermined pressure is reached, the various valves change state, allowing the high pressure side of the compressor to empty into the accumulator. This pushes the lower pressure crankcase gases out of the accumulator through a different conduit to the intake manifold. These crankcase gases are then burned in the cylinders and the crankcase gases are not vented directly to the atmosphere.