MULTI-CYLINDER TWO STROKE ENGINE CRANKCASE SEALING

摘要

A multi-cylinder two stroke cycle internal combustion engine of known construction having an individual crankcase compartment for each cylinder (11) formed in a crankcase (12), said crankcase (12) including a wall (25, 26) separating two adjacent crankcase compartments. A crankshaft (13) extends through the wall (25, 26) with a journal (29) thereof supported in a bearing assembly (30) having an outer bearing ring (32) non-rotatably mounted in the wall (25, 26). The outer bearing ring (32) having an axial extent greater than the thickness of the wall (25, 26) to provide an internal annular surface co-axial with a shoulder (36) on the crankshaft that presents an opposing external annular surface to the internal annular surface of the bearing ring (32). A fluid seal is provided between the internal and external annular surfaces to prevent the passage of gas between the crankcase cavities.